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Sample records for basin northwest china

  1. Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

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    C. Liu

    2015-05-01

    Full Text Available Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

  2. Modeled effects of irrigation on surface climate in the Heihe River Basin, Northwest China

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    Zhang, Xuezhen; Xiong, Zhe; Tang, Qiuhong

    2017-08-01

    In Northwest China, water originates from the mountain area and is largely used for irrigation agriculture in the middle reaches. This study investigates the local and remote impact of irrigation on regional climate in the Heihe River Basin, the second largest inland river basin in Northwest China. An irrigation scheme was developed and incorporated into the Weather Research and Forecasting (WRF) model with the Noah-MP land surface scheme (WRF/Noah-MP). The effects of irrigation is assessed by comparing the model simulations with and without consideration of irrigation (hereafter, IRRG and NATU simulations, respectively) for five growth seasons (May to September) from 2009 to 2013. As consequences of irrigation, daily mean temperature decreased by 1.7°C and humidity increased by 2.3 g kg-1 (corresponding to 38.5%) over irrigated area. The temperature and humidity of IRRG simulation matched well with the observations, whereas NATU simulation overestimated temperature and underestimated humidity over irrigated area. The effects on temperature and humidity are generally small outside the irrigated area. The cooling and wetting effects have opposing impacts on convective precipitation, resulting in a negligible change in localized precipitation over irrigated area. However, irrigation may induce water vapor convergence and enhance precipitation remotely in the southeastern portion of the Heihe River Basin.

  3. The Implication of Climate Signal for Precipitation in the Heihe River Basin, Northwest China

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    Fei Wang

    2016-01-01

    Full Text Available This paper studies the stochastic dynamic variability of precipitation, for the upper, middle, and lower reaches of the Heihe River basin in Northwest China, by employing Mann-Kendall statistic, Pettitt test, and wavelet transform methods. The possible associations with three prominent climatic patterns, El Niño-Southern Oscillation (ENSO, Artic Oscillation (AO, and Indian Ocean Dipole (IOD, are examined by using multiscale wavelet coherence method. No significant trend is identified for the interannual precipitation variability. However, about 2-year significant variability is detected for the lower reach of the Heihe River basin, and this dominating precipitation variability is essentially depicted by AO. The possible influences of ENSO are exerted on long-term timescale, 8–16 years. The obtained knowledge is helpful for the predications of extreme hydroclimatological events and better reservoir operations for regional water resources.

  4. Unconformity structures controlling stratigraphic reservoirs in the north-west margin of Junggar basin, North-west China

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    Wu, Kongyou; Paton, Douglas; Zha, Ming

    2013-03-01

    Tectonic movements formed several unconformities in the north-west margin of the Junggar basin. Based on data of outcrop, core, and samples, the unconformity is a structural body whose formation associates with weathering, leaching, and onlap. At the same time, the structural body may be divided into three layers, including upper layer, mid layer, and lower layer. The upper layer with good primary porosity serves as the hydrocarbon migration system, and also accumulates the hydrocarbon. The mid layer with compactness and ductility can play a role as cap rock, the strength of which increases with depth. The lower layer with good secondary porosity due to weathering and leaching can form the stratigraphic truncation traps. A typical stratigraphic reservoir lying in the unconformity between the Jurassic and Triassic in the north-west margin of the Junggar basin was meticulously analyzed in order to reveal the key controlling factors. The results showed that the hydrocarbon distribution in the stratigraphic onlap reservoirs was controlled by the onlap line, the hydrocarbon distribution in the stratigraphic truncation reservoirs was confined by the truncation line, and the mid layer acted as the key sealing rock. So a conclusion was drawn that "two lines (onlap line and truncation line) and a body (unconformity structural body)" control the formation and distribution of stratigraphic reservoirs.

  5. Baseflow simulation using SWAT model in an inland river basin in Tianshan Mountains, Northwest China

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    Y. Luo

    2012-04-01

    Full Text Available Baseflow is an important component in hydrological modeling. The complex streamflow recession process complicates the baseflow simulation. In order to simulate the snow and/or glacier melt dominated streamflow receding quickly during the high-flow period but very slowly during the low-flow period in rivers in arid and cold northwest China, the current one-reservoir baseflow approach in SWAT (Soil Water Assessment Tool model was extended by adding a slow- reacting reservoir and applying it to the Manas River basin in the Tianshan Mountains. Meanwhile, a digital filter program was employed to separate baseflow from streamflow records for comparisons. Results indicated that the two-reservoir method yielded much better results than the one-reservoir one in reproducing streamflow processes, and the low-flow estimation was improved markedly. Nash-Sutcliff efficiency values at the calibration and validation stages are 0.68 and 0.62 for the one-reservoir case, and 0.76 and 0.69 for the two-reservoir case. The filter-based method estimated the baseflow index as 0.60, while the model-based as 0.45. The filter-based baseflow responded almost immediately to surface runoff occurrence at onset of rising limb, while the model-based responded with a delay. In consideration of watershed surface storage retention and soil freezing/thawing effects on infiltration and recharge during initial snowmelt season, a delay response is considered to be more reasonable. However, a more detailed description of freezing/thawing processes should be included in soil modules so as to determine recharge to aquifer during these processes, and thus an accurate onset point of rising limb of the simulated baseflow.

  6. Organic petrology and geochemistry of mudrocks from the lacustrine Lucaogou Formation, Santanghu Basin, northwest China: Application to lake basin evolution

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    Hackley, Paul C.; Fishman, Neil; Wu, Tao; Baugher, Gregory

    2016-01-01

    Exploration for tight oil in the frontier Santanghu Basin of northwest China has resulted in recent commercial discoveries sourced from the lacustrine Upper Permian Lucaogou Formation, already considered a “world class source rock” in the Junggar Basin to the west. Here we apply an integrated analytical program to carbonate-dominated mudrocks from the Lucaogou Formation in Santanghu Basin to document the nature of organic matter (OM) in the context of an evolving lake system. The organic-rich samples (TOC 2.8–11.4 wt%; n = 10) were widely spaced from an ~ 200 m cored section, interpreted from textural and mineralogical evidence to document transition from a lower under-filled to an overlying balanced-filled lake. Organic matter is dominated by moderate to strongly fluorescent amorphous material with Type I geochemical signature (HI values 510–755; n = 10) occurring in a continuum from lamellar stringers, 10–20 μm thick, some ≥ 1 mm in length (possible microbial mat; preserved only in lower under-filled section) to finely-disseminated amorphous groundmass intimately intermixed with mineral matrix. Biomarkers for methanotrophs and photosynthetic cyanobacteria indicate a complex microbial consortium. A unicellular prasinophyte green alga(?), similar to Tasmanites in marine rocks, is present as discrete flattened discs 50–100 μm in diameter. Type III OM including vitrinite (some fluorescent) and inertinite also is abundant. Solid bitumen, indicating local kerogen conversion, fills voids and occurs throughout the cored section. Vitrinite reflectance values are 0.47–0.58%, consistent with strong OM fluorescence but may be “suppressed”. Other proxies, e.g., biomarker parameters, indicate the Lucaogou Formation is in the early oil window at this location. On average, slightly more amorphous OM and telalginite are present in the lower section, consistent with a shallow, stratified, saline environment with low sediment dilution. More

  7. Three-Dimensional Modeling of Groundwater Ages and Implications for Sustainable Groundwater Management in the Ordos Basin, Northwest China

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    Yu, C.; Cao, G.; Yao, Y.; Hu, F.; Zheng, C.

    2010-12-01

    The Ordos Basin is located in the arid northwest of China. The basin encompasses parts of Shaanxi, Gansu, Shanxi and Inner Mongolia provinces with a total area of 360,000 km2. The region has an abundant reserve of coal and natural gas, hence it is a key energy base for China. However, economic development in the region is hampered by severe water scarcity. Sustainable management of limited groundwater resources is of major concern. In this study, we applied a version of the MT3DMS solute transport model to simulate the three-dimensional distribution of mean groundwater ages in the confined Cretaceous sandstone aquifer in the Ordos Basin. The groundwater age model was constrained by comparing the simulated mean ages with carbon-14 age data collected at over 100 observation wells. Spatial distribution of groundwater ages in a large basin simulated by a solute transport model and calibrated by field-measured isotopic age data provides a unique opportunity to analyze and quantify the sustainability of groundwater resources. Younger groundwater represents a more dynamic system with a higher capability for recharge and renewal. On the other hand, older groundwater indicates a more stagnant system with a lower capability for recharge and renewal. Thus, numerical simulation of groundwater ages can be used as a valuable management tool to evaluate and ensure sustainability of groundwater resources.

  8. Groundwater sustainability and groundwater/surface-water interaction in arid Dunhuang Basin, northwest China

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    Lin, Jingjing; Ma, Rui; Hu, Yalu; Sun, Ziyong; Wang, Yanxin; McCarter, Colin P. R.

    2018-03-01

    The Dunhuang Basin, a typical inland basin in northwestern China, suffers a net loss of groundwater and the occasional disappearance of the Crescent Lake. Within this region, the groundwater/surface-water interactions are important for the sustainability of the groundwater resources. A three-dimensional transient groundwater flow model was established and calibrated using MODFLOW 2000, which was used to predict changes to these interactions once a water diversion project is completed. The simulated results indicate that introducing water from outside of the basin into the Shule and Danghe rivers could reverse the negative groundwater balance in the Basin. River-water/groundwater interactions control the groundwater hydrology, where river leakage to the groundwater in the Basin will increase from 3,114 × 104 m3/year in 2017 to 11,875 × 104 m3/year in 2021, and to 17,039 × 104 m3/year in 2036. In comparison, groundwater discharge to the rivers will decrease from 3277 × 104 m3/year in 2017 to 1857 × 104 m3/year in 2021, and to 510 × 104 m3/year by 2036; thus, the hydrology will switch from groundwater discharge to groundwater recharge after implementing the water diversion project. The simulation indicates that the increased net river infiltration due to the water diversion project will raise the water table and then effectively increasing the water level of the Crescent Lake, as the lake level is contiguous with the water table. However, the regional phreatic evaporation will be enhanced, which may intensify soil salinization in the Dunhuang Basin. These results can guide the water allocation scheme for the water diversion project to alleviate groundwater depletion and mitigate geo-environmental problem.

  9. Heat flow, deep formation temperature and thermal structure of the Tarim Basin, northwest China

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    Liu, Shaowen; Lei, Xiao; Feng, Changge; Li, Xianglan

    2016-04-01

    Geothermal regime of a sedimentary basin not only provides constraint on understanding the basin formation and evolution, but also offers fundamental parameters for hydrocarbon resources assessment. As one of three Precambrian blocks in China, the Tarim craton is also a current hydrocarbon exploration target where the largest sedimentary basin (Tarim Basin) develops with great potential. Although considerable advancement of geothermal regime of this basin has been made during the past decades, nearly all the temperature data in previous studies are from the exploration borehole formation testing temperatures. Recently, we have conducted the steady-state temperature logging in the Tarim basin, and measured abundant rock thermal properties, enabling us to re-visit the thermal regime of this area with more confidence. Our results show that the present-day geothermal gradients for the Tarim Basin vary from 23 K/km to 27 K/km, with a mean of 22 K/km; the values of heat flow range from 40 mW/m2 to 49 mW/m2, with a mean of 43 mW/m2. These new data confirmed that the Tarim Basin has relatively low heat flow and shares similar geothermal regime with other Precambrian cratons in the world. In addition, the new temperatures from the steady-state logs are larger than the bottom hole temperatures (BHT) as 22 degree Celsius, indicating the thermal non-equilibrium for the BHTs used in previous studies. Spatial distribution of the estimated formation temperatures-at-depth of 1~5km within the basin is similar and mainly controlled by crystalline basement pattern. Generally, the temperatures at the depth of 1km range from 29 to 41 degree Celsius, with a mean of 35 degree Celsius; while the temperatures at 3km vary from 63 to 100 degree Celsius, and the mean is 82 degree Celsius; at 5km below the surface, the temperatures fall into a range between 90 and 160 degree Celsius, with a mean of 129 degree Celsius. We further proposed the long-term low geothermal background and large burial

  10. Analysis of agricultural land use change in the middle reach of the Heihe River Basin, Northwest China.

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    Fu, Li; Zhang, Lanhui; He, Chansheng

    2014-03-04

    The Heihe River Basin (HRB) is the second largest inland river basin in arid Northwest China. The expanding agricultural irrigation, growing industrialization, and increasing urban development in the middle reach have depleted much of the river flow to the lower reach, degrading the corresponding ecosystems. Since the enactment of the State Council of China's new HRB water allocation policy in 2000 tremendous land use and land cover (LULC) changes have taken place to reduce water consumption in the middle reach and deliver more water downstream. This paper analyzes LULC changes during the period of 2000-2009 to understand how the changing land use patterns have altered water resource dynamics in the region. Results, while yet to be further verified in the field, show that from 2000 to 2009, urban, agricultural land, rangeland, and forest areas have increased, and barren area has decreased. Within the cropland, rice (a high water consumption crop) planting area decreased, while corn and wheat (relatively lower water consumption crops) planting areas increased. These changes in land use patterns, especially in the agricultural zones, have ensured the discharge of the required amount of water to the lower reach.

  11. The occurrence, sources and spatial characteristics of soil salt and assessment of soil salinization risk in Yanqi basin, northwest China.

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    Zhaoyong, Zhang; Abuduwaili, Jilili; Yimit, Hamid

    2014-01-01

    In order to evaluate the soil salinization risk of the oases in arid land of northwest China, we chose a typical oasis-the Yanqi basin as the research area. Then, we collected soil samples from the area and made comprehensive assessment for soil salinization risk in this area. The result showed that: (1) In all soil samples, high variation was found for the amount of Ca2+ and K+, while the other soil salt properties had moderate levels of variation. (2) The land use types and the soil parent material had a significant influence on the amount of salt ions within the soil. (3) Principle component (PC) analysis determined that all the salt ion values, potential of hydrogen (pHs) and ECs fell into four PCs. Among them, PC1 (C1-, Na+, SO4(2-), EC, and pH) and PC2 (Ca2+, K+, Mg2+and total amount of salts) are considered to be mainly influenced by artificial sources, while PC3 and PC4 (CO3(-) and HCO3(2-)) are mainly influenced by natural sources. (4) From a geo-statistical point of view, it was ascertained that the pH and soil salt ions, such as Ca2+, Mg2+ and HCO3(-), had a strong spatial dependency. Meanwhile, Na+ and Cl- had only a weak spatial dependency in the soil. (5) Soil salinization indicators suggested that the entire area had a low risk of soil salinization, where the risk was mainly due to anthropogenic activities and climate variation. This study can be considered an early warning of soil salinization and alkalization in the Yanqi basin. It can also provide a reference for environmental protection policies and rational utilization of land resources in the arid region of Xinjiang, northwest China, as well as for other oases of arid regions in the world.

  12. The occurrence, sources and spatial characteristics of soil salt and assessment of soil salinization risk in Yanqi basin, northwest China.

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    Zhang Zhaoyong

    Full Text Available In order to evaluate the soil salinization risk of the oases in arid land of northwest China, we chose a typical oasis-the Yanqi basin as the research area. Then, we collected soil samples from the area and made comprehensive assessment for soil salinization risk in this area. The result showed that: (1 In all soil samples, high variation was found for the amount of Ca2+ and K+, while the other soil salt properties had moderate levels of variation. (2 The land use types and the soil parent material had a significant influence on the amount of salt ions within the soil. (3 Principle component (PC analysis determined that all the salt ion values, potential of hydrogen (pHs and ECs fell into four PCs. Among them, PC1 (C1-, Na+, SO4(2-, EC, and pH and PC2 (Ca2+, K+, Mg2+and total amount of salts are considered to be mainly influenced by artificial sources, while PC3 and PC4 (CO3(- and HCO3(2- are mainly influenced by natural sources. (4 From a geo-statistical point of view, it was ascertained that the pH and soil salt ions, such as Ca2+, Mg2+ and HCO3(-, had a strong spatial dependency. Meanwhile, Na+ and Cl- had only a weak spatial dependency in the soil. (5 Soil salinization indicators suggested that the entire area had a low risk of soil salinization, where the risk was mainly due to anthropogenic activities and climate variation. This study can be considered an early warning of soil salinization and alkalization in the Yanqi basin. It can also provide a reference for environmental protection policies and rational utilization of land resources in the arid region of Xinjiang, northwest China, as well as for other oases of arid regions in the world.

  13. How to allocate water resources under climate change in the arid endorheic river basin, Northwest China

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    Zhang, A.; Feng, D.; Tian, Y.; Zheng, Y.

    2017-12-01

    Water resource is of fundamental importance to the society and ecosystem in arid endorheic river basins, and water-use conflicts between upstream and downstream are usually significant. Heihe river basin (HRB) is the second largest endorheic river basin in china, which is featured with dry climate, intensively irrigated farmlands in oases and significant surface water-groundwater interaction. The irrigation districts in the middle HRB consume a large portion of the river flow, and the low HRB, mainly Gobi Desert, has an extremely vulnerable ecological environment. The water resources management has significantly altered the hydrological processes in HRB, and is now facing multiple challenges, including decline of groundwater table in the middle HRB, insufficient environmental flow for the lower HRB. Furthermore, future climate change adds substantial uncertainty to the water system. Thus, it is imperative to have a sustainable water resources management in HRB in order to tackle the existing challenges and future uncertainty. Climate projection form a dynamical downscaled climate change scenario shows precipitation will increase at a rate of approximately 3 millimeter per ten years and temperature will increase at a rate of approximately 0.2 centigrade degree per ten years in the following 50 years in the HRB. Based on an integrated ecohydrological model, we evaluated how the climate change and agricultural development would collaboratively impact the water resources and ecological health in the middle and lower HRB, and investigated how the water management should cope with the complex impact.

  14. Hydrological Impacts of Land Use Change and Climate Variability in the Headwater Region of the Heihe River Basin, Northwest China

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    Zhang, Ling; Nan, Zhuotong; Xu, Yi; Li, Shuo

    2016-01-01

    Land use change and climate variability are two key factors impacting watershed hydrology, which is strongly related to the availability of water resources and the sustainability of local ecosystems. This study assessed separate and combined hydrological impacts of land use change and climate variability in the headwater region of a typical arid inland river basin, known as the Heihe River Basin, northwest China, in the recent past (1995–2014) and near future (2015–2024), by combining two land use models (i.e., Markov chain model and Dyna-CLUE) with a hydrological model (i.e., SWAT). The potential impacts in the near future were explored using projected land use patterns and hypothetical climate scenarios established on the basis of analyzing long-term climatic observations. Land use changes in the recent past are dominated by the expansion of grassland and a decrease in farmland; meanwhile the climate develops with a wetting and warming trend. Land use changes in this period induce slight reductions in surface runoff, groundwater discharge and streamflow whereas climate changes produce pronounced increases in them. The joint hydrological impacts are similar to those solely induced by climate changes. Spatially, both the effects of land use change and climate variability vary with the sub-basin. The influences of land use changes are more identifiable in some sub-basins, compared with the basin-wide impacts. In the near future, climate changes tend to affect the hydrological regimes much more prominently than land use changes, leading to significant increases in all hydrological components. Nevertheless, the role of land use change should not be overlooked, especially if the climate becomes drier in the future, as in this case it may magnify the hydrological responses. PMID:27348224

  15. Hydrological Impacts of Land Use Change and Climate Variability in the Headwater Region of the Heihe River Basin, Northwest China.

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    Zhang, Ling; Nan, Zhuotong; Xu, Yi; Li, Shuo

    2016-01-01

    Land use change and climate variability are two key factors impacting watershed hydrology, which is strongly related to the availability of water resources and the sustainability of local ecosystems. This study assessed separate and combined hydrological impacts of land use change and climate variability in the headwater region of a typical arid inland river basin, known as the Heihe River Basin, northwest China, in the recent past (1995-2014) and near future (2015-2024), by combining two land use models (i.e., Markov chain model and Dyna-CLUE) with a hydrological model (i.e., SWAT). The potential impacts in the near future were explored using projected land use patterns and hypothetical climate scenarios established on the basis of analyzing long-term climatic observations. Land use changes in the recent past are dominated by the expansion of grassland and a decrease in farmland; meanwhile the climate develops with a wetting and warming trend. Land use changes in this period induce slight reductions in surface runoff, groundwater discharge and streamflow whereas climate changes produce pronounced increases in them. The joint hydrological impacts are similar to those solely induced by climate changes. Spatially, both the effects of land use change and climate variability vary with the sub-basin. The influences of land use changes are more identifiable in some sub-basins, compared with the basin-wide impacts. In the near future, climate changes tend to affect the hydrological regimes much more prominently than land use changes, leading to significant increases in all hydrological components. Nevertheless, the role of land use change should not be overlooked, especially if the climate becomes drier in the future, as in this case it may magnify the hydrological responses.

  16. Probability Modeling of Precipitation Extremes over Two River Basins in Northwest of China

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    Zhanling Li

    2015-01-01

    Full Text Available This paper is focused on the probability modeling with a range of distribution models over two inland river basins in China, together with the estimations of return levels on various return periods. Both annual and seasonal maximum precipitations (MP are investigated based on daily precipitation data at 13 stations from 1960 to 2010 in Heihe River and Shiyang River basins. Results show that GEV, Burr, and Weibull distributions provide the best fit to both annual and seasonal MP. Exponential and Pareto 2 distributions show the worst fit. The estimated return levels for spring MP show decreasing trends from the upper to the middle and then to the lower reaches totally speaking. Summer MP approximates to annual MP both in the quantity and in the spatial distributions. Autumn MP shows a little higher value in the estimated return levels than Spring MP, while keeping consistent with spring MP in the spatial distribution. It is also found that the estimated return levels for annual MP derived from various distributions differ by 22%, 36%, and 53% on average at 20-year, 50-year, and 100-year return periods, respectively.

  17. Significance and effect of ecological rehabilitation project in inland river basins in northwest China.

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    Wang, Yu; Feng, Qi; Chen, Lijuan; Yu, Tengfei

    2013-07-01

    The Ecological Water Transfer and Rehabilitation Project in the arid inland area of northwest China is an important measure in restoring a deteriorated ecosystem. However, the sustainability of the project is affected by many socio-economic factors. This article examines the attitudes of the local populace toward the project, its impact on the livelihood of the people, and the positive effects of water-efficient agricultural practices in Ejina County. Related data were collected through questionnaire surveys and group discussions. The results identified three critical issues that may influence the sustainability of the project in the study area. The first issue relates to the impact of the project on the livelihood of local herdsmen. The potential for the sustainability of the project is compromised because the livelihood of the herdsmen greatly depends on the compensation awarded by the project. The second issue is that the project did not raise the water resource utilization ratio, which may undermine its final purpose. Finally, the compensation provided by the project considers losses in agriculture, but neglects the externalities and public benefit of eco-water. Thus, appropriate compensation mechanisms should be established and adopted according to local economic, environmental, and social conditions. Some recommendations for improving the sustainability of the project are provided based on the results of this study.

  18. Sediment provenance in the Shudu Lake basin, northwest Yunnan Province, China, as revealed by composite fingerprinting

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    Yao, Yuan

    2013-09-01

    Full Text Available Composite fingerprinting represents an effective method of reconstructing sediment-source changes in remote areas where long-term hydrological and sediment accretion records do not exist. A ca. 50-year record of sediment deposition was determined for a small catchment at Shudu, situated in northwest Yunnan Province, China. Woodland, pasture, shrubland and channel bank material are identified as the most likely sediment sources and this was confirmed using a composite sediment fingerprinting approach. Based on the findings of the fingerprinting technique, variations in the geochemical signature associated with lacustrine sediment deposits indicate that 49.2 % of the total catchment sediment yield over an approximate 50-year period originated from channel banks. In contrast, 19.2 % originated from pasture, 18.6 % originated from shrubland, and 13 % from woodland. The relative contributions of eroded sediment from both woodland and shrubland have generally remained stable over the period investigated, whereas the contribution of material from pasture has increased over recent decades. This is tentatively attributed to increased grazing pressure, which is probably due to increased stocking densities which have gradually exceeded the carrying capacity and regenerative capabilities of the available grassland.

  19. Evaluating Impacts of Industrial Transformation on Water Consumption in the Heihe River Basin of Northwest China

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    Feng Wu

    2014-11-01

    Full Text Available Growing water scarcity is one of the central challenges for sustainability in China, given its burgeoning industry and huge population, especially in the arid and semi-arid inland river basin where precipitation is very limited. Industrial transformation is an important engine of economic growth, which is required to be implemented by governments at all levels in China. Economic models have generally been applied to evaluate the effects of economic policy change (e.g., industrial transformation or adjustment of price on the allocation of production factors. The computable general equilibrium (CGE model is an effective tool to reallocate the primary factors across sectors for different industrial transformation scenarios. In this research, we first briefly introduced the principles and structure of the CGE model, which embeds water resources as a primary factor of production. Then we chose Zhangye as an example to evaluate the impacts of industrial transformation on water consumption under three designed scenarios with the water-embedded CGE model. Simulation results showed that there will be considerable water saving benefit from industrial transformation when the output value of secondary industry and tertiary industry increases and the contribution of the planting sector to the total output value decreases. Finally, we put forward a scheme that can improve water utilization efficiency in policy options.

  20. Responses of Vegetation Growth to Climatic Factors in Shule River Basin in Northwest China: A Panel Analysis

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    Jinghui Qi

    2017-03-01

    Full Text Available The vegetation response to climatic factors is a hot topic in global change research. However, research on vegetation in Shule River Basin, which is a typical arid region in northwest China, is still limited, especially at micro scale. On the basis of Moderate-resolution Imaging Spectroradiometer (MODIS Normalized Difference Vegetation Index (NDVI data and daily meteorological data, employing panel data models and other mathematical models, the aim of this paper is to reveal the interactive relationship between vegetation variation and climatic factors in Shule River Basin. Results show that there is a widespread greening trend in the whole basin during 2000–2015, and 80.28% of greening areas (areas with vegetation improvement are distributed over upstream region, but the maximum vegetation variation appears in downstream area. The effects of climate change on NDVI lag about half to one month. The parameters estimated using panel data models indicate that precipitation and accumulated temperature have positive contribution to NDVI. With every 1-mm increase in rainfall, NDVI increases by around 0.223‰ in upstream area and 0.6‰ in downstream area. With every 1-°C increase in accumulated temperature, NDVI increases by around 0.241‰ in upstream area and 0.174‰ in downstream area. Responses of NDVI to climatic factors are more sensitive when these factors are limiting than when they are not limiting. NDVI variation has performance in two seasonal and inter-annual directions, and the range of seasonal change is far more than that of inter-annual change. The inverted U-shaped curve of the variable intercepts reflects the seasonal change. Our results might provide some scientific basis for the comprehensive basin management.

  1. Analysis of Agricultural Land Use Change in the Middle Reach of the Heihe River Basin, Northwest China

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    Li Fu

    2014-03-01

    Full Text Available The Heihe River Basin (HRB is the second largest inland river basin in arid Northwest China. The expanding agricultural irrigation, growing industrialization, and increasing urban development in the middle reach have depleted much of the river flow to the lower reach, degrading the corresponding ecosystems. Since the enactment of the State Council of China’s new HRB water allocation policy in 2000 tremendous land use and land cover (LULC changes have taken place to reduce water consumption in the middle reach and deliver more water downstream. This paper analyzes LULC changes during the period of 2000–2009 to understand how the changing land use patterns have altered water resource dynamics in the region. Results, while yet to be further verified in the field, show that from 2000 to 2009, urban, agricultural land, rangeland, and forest areas have increased, and barren area has decreased. Within the cropland, rice (a high water consumption crop planting area decreased, while corn and wheat (relatively lower water consumption crops planting areas increased. These changes in land use patterns, especially in the agricultural zones, have ensured the discharge of the required amount of water to the lower reach.

  2. Organic geochemistry and petroleum geology, tectonics and basin analysis of southern Tarim and northern Qaidam basins, northwest China

    Science.gov (United States)

    Hanson, Andrew Dean

    Organic geochemistry of oils from the Tarim basin, NW China, distinguish at least seven genetic groups of oils. The largest group are derived from Middle-Upper Ordovician anoxic slope-facies marls coincident with the margins of structural uplifts. Other groups include non-marine derived oils in the Luntai uplift, from southwest Tarim, in the Kuqa depression, and west of the Bachu uplift. A seep sample from west of Kashi clusters with Luntai oils. These results suggest that numerous source-rock horizons occur, but they are really restricted. Organic geochemistry of oils from northern Qaidam defines a family of hypersaline, anoxic lacustrine derived oils. Cenozoic outcrop samples from northern Qaidam are too organic lean to be of source quality, but dark laminated upper Oligocene mudstones from the Shi 28 well are of fair to good quality. Biomarkers provide a good correlation between the oils and the core samples. Organic matter is from algae and bacteria and lacks terrestrial material. Hydrocarbons are contained in upper Oligocene, Miocene, and Pliocene reservoirs. Eight oils are from NW Qaidam, but one sample comes from NE Qaidam, an area previously believed to only produce oils derived from Jurassic source rocks. Thus an unidentified Cenozoic source rock occurs in NE Qaidam. Thermal modeling indicates generation occurred in northwestern Qaidam within the last 3 million years, agreeing with observed low maturity biomarker parameters. Cenozoic stratigraphy in northern Qaidam and southern Tarim basins record the tectonic history of the surrounding structural/topographic elements. Paleocurrents record flow away from adjacent ranges from the Miocene to the present. Provenance data tie sediments to adjacent structural elements. Petrography indicates increasingly immature sandstones in Miocene and younger sediments relative to pre-Miocene samples. Apatite fission-track results from southeastern Tarim yield a cooling age of 17 +/- 1 Ma indicative of unroofing since at

  3. Multi-tracer investigation of river and groundwater interactions: a case study in Nalenggele River basin, northwest China

    Science.gov (United States)

    Xu, Wei; Su, Xiaosi; Dai, Zhenxue; Yang, Fengtian; Zhu, Pucheng; Huang, Yong

    2017-11-01

    Environmental tracers (such as major ions, stable and radiogenic isotopes, and heat) monitored in natural waters provide valuable information for understanding the processes of river-groundwater interactions in arid areas. An integrated framework is presented for interpreting multi-tracer data (major ions, stable isotopes (2H, 18O), the radioactive isotope 222Rn, and heat) for delineating the river-groundwater interactions in Nalenggele River basin, northwest China. Qualitative and quantitative analyses were undertaken to estimate the bidirectional water exchange associated with small-scale interactions between groundwater and surface water. Along the river stretch, groundwater and river water exchange readily. From the high mountain zone to the alluvial fan, groundwater discharge to the river is detected by tracer methods and end-member mixing models, but the river has also been identified as a losing river using discharge measurements, i.e. discharge is bidirectional. On the delta-front of the alluvial fan and in the alluvial plain, in the downstream area, the characteristics of total dissolved solids values, 222Rn concentrations and δ18O values in the surface water, and patterns derived from a heat-tracing method, indicate that groundwater discharges into the river. With the environmental tracers, the processes of river-groundwater interaction have been identified in detail for better understanding of overall hydrogeological processes and of the impacts on water allocation policies.

  4. Towards a digital watershed, with a case study in the Heihe River Basin of northwest China

    Science.gov (United States)

    Li, X.; Cheng, G.-D.; Ma, M.-G.; Lu, L.; Ge, Y.-C.

    2003-04-01

    Integrated watershed study and river basin management needs integrated database and integrated hydrological and water resource models. We define digital watershed as a web-based information system that integrates data from different sources and in different scales through both information technology and hydrological modeling. In the last two years, a “digital basin” of the Heihe River Basin, which is a well-studied in-land catchment in China’s arid region was established. More than 6 Gb of in situ observation data, GIS maps, and remotely sensed data have been uploaded to the Heihe web site. Various database and dynamic web techniques such as PHP, ASP, XML, VRML are being used for data service. In addition, the DIAL (Data and Information Access Link), IMS (Internet Map Server) and other Web-GISs are used to make GIS and remote sensing datasets of the Heihe River Basin available and accessible on the Internet. We also have developed models for estimating the evapotranspiration, bio-physical parameters, and snow runoff. These methods can be considered as the elements to build up the integrated watershed model that can be used for integrated management of the Heihe River Basin. The official domain name of the digital Heihe River Basin is heihe.westgis.ac.cn

  5. Groundwater mixing and mineralization processes in a mountain-oasis-desert basin, northwest China: hydrogeochemistry and environmental tracer indicators

    Science.gov (United States)

    Ma, Bin; Jin, Menggui; Liang, Xing; Li, Jing

    2018-02-01

    Hydrogeochemistry and environmental tracers (2H, 18O, 87Sr/86Sr) in precipitation, river and reservoir water, and groundwater have been used to determine groundwater recharge sources, and to identify mixing characteristics and mineralization processes in the Manas River Basin (MRB), which is a typical mountain-oasis-desert ecosystem in arid northwest China. The oasis component is artificial (irrigation). Groundwater with enriched stable isotope content originates from local precipitation and surface-water leakage in the piedmont alluvial-oasis plain. Groundwater with more depleted isotopes in the north oasis plain and desert is recharged by lateral flow from the adjacent mountains, for which recharge is associated with high altitude and/or paleo-water infiltrating during a period of much colder climate. Little evaporation and isotope exchange between groundwater and rock and soil minerals occurred in the mountain, piedmont and oasis plain. Groundwater δ2H and δ18O values show more homogeneous values along the groundwater flow direction and with well depths, indicating inter-aquifer mixing processes. A regional contrast of groundwater allows the 87Sr/86Sr ratios and δ18O values to be useful in a combination with Cl, Na, Mg, Ca and Sr concentrations to distinguish the groundwater mixing characteristics. Two main processes are identified: groundwater lateral-flow mixing and river leakage in the piedmont alluvial-oasis plain, and vertical mixing in the north oasis plain and the desert. The 87Sr/86Sr ratios and selected ion ratios reveal that carbonate dissolution and mixing with silicate from the southern mountain area are primarily controlling the strontium isotope hydrogeochemistry.

  6. Model identification and control of development of deeply buried paleokarst reservoir in the central Tarim Basin, northwest China

    Science.gov (United States)

    Yu, Jingbo; Li, Zhong; Yang, Liu; Han, Yinxue

    2018-04-01

    The paleokarst reservoirs of the Ordovician Yingshan formation, rich in oil and gas, are deeply buried in the central Tarim Basin, northwest China. Dozens of imaging well-logs in this region reveal five typical paleokarst features, including solution vugs, solution-enlarged fractures, filled caves, unfilled caves and collapsed caves, as well as two typical paleokarst structures located in different paleotopographic sites, including paleokarst vadose and phreatic zones. For seismic data, the large wave impedance contrast between the paleocave system and the surrounding rocks leads to a strong seismic reflection, which is highlighted as a bead-like ‘bright spot’ in a seismic section. By quantitatively estimating the seismic resolution limits of deep seismic reflections, a single paleocave cannot be identified from a seismic profile, and the bead-like reflection represents an entire paleocave complex. The spectral decomposition technique was employed to depict the planar shape and semi-quantitatively measure the size of the paleocave complexes. The results indicate that the sizes of the paleokarst caves are all small, and most of the karst caves are nearly completely filled by clay and calcite. The small cave size and the effective support of cave fills for the overlying strata mean that some individual paleocaves in a paleocave complex are preserved at a burial depth of more than 6000 m. Paleotopography and faults strongly impact the distribution of paleokarst reservoirs. Well-developed paleokarst reservoirs are generally located in paleotopographic highlands and on slopes, and for a specific paleotopographic site, the distribution of paleokarst reservoirs is obviously controlled by NW-SE trending faults. The most favorable area for paleokarst development is the Tazhong No. 10 fault zone, a faulted anticline bounded by two NW-SE trending back thrusts.

  7. Behavior of Agricultural water users induced hydro-climatic cycle change in Heihe River Basin, in the northwest of china

    Science.gov (United States)

    Wu, F.; Deng, X.; Cai, X.; Zhang, X.; Zhang, Q.

    2017-12-01

    Water allocation unbalance is the most important driving force of ecological degradation in the Heihe River Basin, where it seems the lifeblood of environment and human society. Water commute complex and frequent in soil, atmosphere, surface and ground face. The balance analysis of Water's transformation based on the WRF (Weather Research Forecasting) and SWAT (Soil and Water Assessment Tool) simulations, puts forward the application of land governance in arid and semi-arid region. In this study, we designed an irrigation scheme using local field experiences and incorporated the irrigation scheme into WRF/Noah-MP model. Then, to test the effects of irrigation scheme on performance of WRF/Noah-MP model, we carried out two simulations with the Heihe watershed, Northwest China, as a case study area. Firstly, the irrigation simulation is meanly about 860 mm across all of 671 cropland grid cells within the Heihe watershed and gradually increases from about 500 mm nearby the foot of Qilian Mountain to the maximum about 1500 mm in the middle and lower reach of Heihe River. Both of regional mean value and spatial heterogeneity are close to ground measurements. Secondly, the irrigation simulation dramatically reduced the mean bias of specified humidity to -0.47 g kg-1 (accounting for 6.0% of observation) and RMSE of temperature to 0.47 °C, respectively, since the irrigation enhanced the surface latent heat and weakened sensible heat to atmosphere. Thirdly, Across the 8 agricultural sites, the correlation coefficient and RMSE increased from 0.75 to 0.80. Finally, we found the surface runoff will increase by 0.46% with SWAT model at irrigation months. Therefore, the irrigation may led to expansion of cultivated land through transformation from groundwater to surface water at some degree. Water authorities should strengthen the tough water management measures to implement measures of total quantity control and raise the efficiency of water resources.

  8. Assessing water footprint at river basin level: a case study for the Heihe River Basin in Northwest China

    NARCIS (Netherlands)

    Zeng, Z.; Liu, J.; Koeneman, P.H.; Zarate, E.; Hoekstra, Arjen Ysbert

    2012-01-01

    Increasing water scarcity places considerable importance on the quantification of water footprint (WF) at different levels. Despite progress made previously, there are still very few WF studies focusing on specific river basins, especially for those in arid and semi-arid regions. The aim of this

  9. Assessing water footprint at river basin level: a case study for the Heihe River Basin in northwest China

    NARCIS (Netherlands)

    Zeng, Z; Liu, J.; Koeneman, P.H.; Zarate, E.; Hoekstra, Arjen Ysbert

    2012-01-01

    Increasing water scarcity places considerable importance on the quantification of water footprint (WF) at different levels. Despite progress made previously, there are still very few WF studies focusing on specific river basins, especially for those in arid and semi-arid regions. The aim of this

  10. Organic geochemistry and hydrocarbon potential contrasts among lithologically different source rocks in the Qingxi Sag, Jiuquan Basin, Northwest China

    Science.gov (United States)

    Zhang, Weiwei; Huang, Zhilong; Gao, Gang; Yin, Yue; Li, Tianjun

    2017-04-01

    Jiuquan Basin, located in the eastern part of Hexi Corridor, is a medium- to small-sized superimposed basin in northwest China. Situated in the southwest of the basin is the Qingxi sag, in which the development of large sets of argillaceous dolomite dominate (lithological assemblage named as LSA) and dolomitic mudstone (LSB), partially being mudstone. From electronical and seismic profile features, the Lower Cretaceous can be divided into the Chijinpu Formation, Xiagou Formation, and Zhonggou Formation in the Qingxi Sag. Moreover, the Xiagou Formation can be divided into four members, represented as K1g0, K1g1, K1g2, and K1g3. The given lithological assemblages and occurrence of particular mineralogical combinations indicate that it is the product of hydrothermal deposition. Lithologically, the argillaceous dolomite and dolomitic mudstone are diametrically different in both mineral contents and types. The integration of field outcrop observation and sampling with laboratory analyses, including solvent extract, Rock-Eval (S1, S2, and Tmax), organic petrography (lithological identification, cement, grain, mineral, and maceral observation), and laboratory modeling of hydrocarbon generation, show that both LSA and LSB contains good hydrocarbon potentials but rather different mineralogical compositions. The concurrence of LSA and LSB indicates the alternate interaction between the hydrothermal deposition and normal lacustrine deposits. The LSA mainly contains Type I kerogen and much lower Pr/Ph ratio, indicating parental material sourced from lacustrine algae and bacteria and much stronger reduction depostional environment. However, the LSB mainly contains Type III kerogen, containing parental material mainly sourced from terrestrial higher plant. And in the mudstone, there is almost no Type I kerogen, indicating no substantial input of lacustrine phytoplankton. The LSA contains TOC value of 1.2-3.2% (wt), averaging 2.1% (wt); while the LSB contains 0.8-2.4% (wt) with

  11. The impact of the winter North Atlantic Oscillation on the frequency of spring dust storms over Tarim Basin in northwest China in the past half-century

    International Nuclear Information System (INIS)

    Zhao Yong; Huang Anning; Zhou Yang; Huang Ying; Zhu Xinsheng

    2013-01-01

    The relationship between the frequency of spring dust storms over Tarim Basin in northwest China and the winter North Atlantic Oscillation (NAO) is investigated by using the observed dust storm frequency (DSF) and the 10 m wind velocity at 36 stations in Tarim Basin and the National Centers for Environment Prediction/National Center for Atmospheric Research reanalysis data for the period 1961–2007. The spring DSF (winter NAO) index shows a clear decreasing (increasing) linear trend over 1961–2007. The winter NAO correlates well with the subsequent spring DSF over Tarim Basin on both interannual and interdecadal time scales and its interannual to interdecadal variation plays an important role in the spring DSF. Two possible physical mechanisms are identified. One is related to the large scale anomalous circulations in spring in the middle to high troposphere modulated by the winter NAO, providing the background of dynamical conditions for the dust storm occurrences. The other is related to the shifts in the local horizontal sea level pressure (SLP) gradients and 10 m wind speed, corresponding to changes in the large scale circulations in spring. The decrease in the local 10 m wind speed due to the reduced horizontal SLP gradients over Tarim Basin during the strong winter NAO years contributes to the decline of the DSF in the subsequent spring. (letter)

  12. Genesis Analysis of High-Gamma Ray Sandstone Reservoir and Its Log Evaluation Techniques: A Case Study from the Junggar Basin, Northwest China

    Directory of Open Access Journals (Sweden)

    Liang Wang

    2013-01-01

    Full Text Available In the Junggar basin, northwest China, many high gamma-ray (GR sandstone reservoirs are found and routinely interpreted as mudstone non-reservoirs, with negative implications for the exploration and exploitation of oil and gas. Then, the high GR sandstone reservoirs’ recognition principles, genesis, and log evaluation techniques are systematically studied. Studies show that the sandstone reservoirs with apparent shale content greater than 50% and GR value higher than 110API can be regarded as high GR sandstone reservoir. The high GR sandstone reservoir is mainly and directly caused by abnormally high uranium enrichment, but not the tuff, feldspar or clay mineral. Affected by formation’s high water sensitivity and poor borehole quality, the conventional logs can not recognize reservoir and evaluate the physical property of reservoirs. Then, the nuclear magnetic resonance (NMR logs is proposed and proved to be useful in reservoir recognition and physical property evaluation.

  13. Scenario-Based Impact Assessment of Land Use/Cover and Climate Changes on Watershed Hydrology in Heihe River Basin of Northwest China

    Directory of Open Access Journals (Sweden)

    Feng Wu

    2015-01-01

    Full Text Available This study evaluated hydrological impacts of potential climate and land use changes in Heihe River Basin of Northwest China. The future climate data for the simulation with Soil and Water Assessment Tool (SWAT were prepared using a dynamical downscaling method. The future land uses were simulated with the Dynamic Land Use System (DLS model by establishing Multinomial Logistic Regression (MNL model for six land use types. In 2006–2030, land uses in the basin will experience a significant change with a prominent increase in urban areas, a moderate increase in grassland, and a great decrease in unused land. Besides, the simulation results showed that in comparison to those during 1981–2005 the temperature and precipitation during 2006–2030 will change by +0.8°C and +10.8%, respectively. The land use change and climate change will jointly make the water yield change by +8.5%, while they will separately make the water yield change by −1.8% and +9.8%, respectively. The predicted large increase in future precipitation and the corresponding decrease in unused land will have substantial impacts on the watershed hydrology, especially on the surface runoff and streamflow. Therefore, to mitigate negative hydrological impacts and utilize positive impacts, both land use and climate changes should be considered in water resource planning for the Heihe River Basin.

  14. Post-Triassic thermal history of the Tazhong Uplift Zone in the Tarim Basin, Northwest China: Evidence from apatite fission-track thermochronology

    Directory of Open Access Journals (Sweden)

    Caifu Xiang

    2013-11-01

    Full Text Available The Tarim Basin is a representative example of the basins developed in the northwest China that are characterized by multiple stages of heating and cooling. In order to better understand its complex thermal history, apatite fission track (AFT thermochronology was applied to borehole samples from the Tazhong Uplift Zone (TUZ. Twelve sedimentary samples of Silurian to Triassic depositional ages were analyzed from depths coinciding with the apatite partial annealing zone (∼60–120 °C. The AFT ages, ranging from 132 ± 7 Ma (from a Triassic sample to 25 ± 2 Ma (from a Carboniferous sample, are clearly younger than their depositional ages and demonstrate a total resetting of the AFT thermometer after deposition. The AFT ages vary among different tectonic belts and decrease from the No. Ten Faulted Zone (133–105 Ma in the northwest, the Central Horst Zone in the middle (108–37 Ma, to the East Buried Hill Zone in the south (51–25 Ma. Given the low magnitude of post-Triassic burial heating evidenced by low vitrinite reflectance values (Ro < 0.7%, the total resetting of the AFT system is speculated to result from the hot fluid flow along the faults. Thermal effects along the faults are well documented by younger AFT ages and unimodal single grain age distributions in the vicinity of the faults. Permian–early Triassic basaltic volcanism may be responsible for the early Triassic total annealing of those samples lacking connectivity with the fault. The above arguments are supported by thermal modeling results.

  15. Soil erosion rates in two karst peak-cluster depression basins of northwest Guangxi, China: Comparison of the RUSLE model with 137Cs measurements

    Science.gov (United States)

    Feng, Teng; Chen, Hongsong; Polyakov, Viktor O.; Wang, Kelin; Zhang, Xinbao; Zhang, Wei

    2016-01-01

    Reliable estimation of erosion in karst areas is difficult because of the heterogeneous nature of infiltration and sub-surface drainage. Understanding the processes involved is a key requirement for managing against karst rock desertification. This study used the revised Universal Soil Loss Equation (RUSLE) to estimate the annual soil erosion rates on hillslopes and compared them with 137Cs budget in the depressions at two typical karst peak-cluster depression basins in northwest Guangxi, southwestern China. Runoff plots data were used to calibrate the slope length factor (L) of the RUSLE model by adjusting the accumulated area threshold. The RUSLE model was sensitive to the value of the threshold and required DEMs with 1 m resolution, due to the discontinuous nature of the overland flow. The average annual soil erosion rates on hillslopes simulated by the RUSLE were 0.22 and 0.10 Mg ha- 1 y- 1 during 2006 through 2011 in the partially cultivated GZ1 and the undisturbed GZ2 basins, respectively. The corresponding deposition rates in the depressions agreed well with the 137Cs records when recent changes in precipitation and land use were taken into consideration. The study suggests that attention should be given to the RUSLE-L factor when applying the RUSLE on karst hillslopes because of the discontinuous nature of runoff and significant underground seepage during storm events that effectively reduces the effects of slope length.

  16. Diamondoid Characterization in Condensate by Comprehensive Two-Dimensional Gas Chromatography with Time-of-Flight Mass Spectrometry: The Junggar Basin of Northwest China

    Science.gov (United States)

    Li, Shuifu; Hu, Shouzhi; Cao, Jian; Wu, Ming; Zhang, Dongmei

    2012-01-01

    Diamondoids in crude oil are useful for assessing the maturity of oil in high maturation. However, they are very difficult to separate and accurately quantify by conventional geochemical methods due to their low abundance in oil. In this paper, we use comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) to study the compounds in condensates from the Junggar Basin of northwest China and address their geological and geochemical applications. GC×GC-TOFMS improves the resolution and separation efficiency of the compounds. It not only separates the compounds that coelute in conventional GC-MS (e.g., 4, 8-dimethyl-diamantane and trimethyl-diamantane) but also allows the identification of compounds that were not previously detected (e.g., trimethyl-diamantane (15A)). A reversed-phase column system improves the separation capabilities over the normal phase column system. The diamondoid indexes indicate that a representative condensate from Well DX 10 is highly mature with equivalent Ro being approximately 1.5%. PMID:23109861

  17. [Ecology-economy harmonious development based on the ecological services value change in Yanqi Basin, Northwest China].

    Science.gov (United States)

    Mamat, Zulpiya; Halik, Umut; Aji, Rouzi; Nurmemet, Ilyas; Anwar, Mirigul; Keyimu, Maierdang

    2015-03-01

    In this paper, we used land use/cover ecosystem service value estimation model and ecological economic coordination degree model to analyze the changes of the ecosystem service value by the land use/cover changes during 1985, 1990, 1996, 2000, 2005 and 2011 in Yanqi Basin, Xin-jiang. Then we evaluated the ecology-economy harmony and the regional differences. The results showed that during 1985-2011, there was an increasing trend in the areas of waters, wetland, sand, cultivated land and construction land in Yanqi Basin. In contrast, that of the saline-alkali land, grassland and woodland areas exhibited a decreasing trend. The ecosystem service value in Yanqi Basin during this period presented an increasing trend, among which the waters and cultivated land contributed most to the total value of ecosystem services, while the grassland and the woodland had obviously declined contribution to the total value of ecosystem services. The research showed that the development of ecological economy in the study area was at a low conflict and low coordination level. So, taking reasonable and effective use of the regional waters and soil resources is the key element to maintain the ecosystem service function and sustainable and harmonious development of economy in Yanqi Basin.

  18. [Relationships among leaf traits and their expression in different vegetation zones in Yanhe River basin, Northwest China].

    Science.gov (United States)

    Guo, Ru; Wen, Zhong-ming; Wang, Hong-xia; Qi, De-hui

    2015-12-01

    This article selected zonal plant communities as the research objects in different vegetation zones in Yanhe River basin. We measured six leaf traits of the dominant species and main accompanying species in each community, and then analyzed the relationships and their changes along with environmental gradients between these traits in order to understand the plant adaptation strategies to the environment changes. The results showed that the specific leaf area was significantly negatively correlated to leaf tissue density, area-based leaf nitrogen and phosphorus concentrations, and significantly positively correlated to mass-based leaf phosphorus concentration. Both the scaling relationships among these traits and plant life strategies were different among the three vegetation zones, the scaling-dependent relationship between leaf tissue density and specific leaf area was stronger in steppe and forest-steppe zones than in forest zone, but the correlations among area-based leaf nitrogen/phosphorus concentrations and specific leaf area and leaf tissue density were more significant in forest zone than in steppe zone. In the arid grassland and forest-steppe zone, plants give priority to defensive and stress resistance strategies, and in relatively moist nutrient-rich forest zone, plants give priority to fast growth and resource optimization allocation strategies.

  19. High-resolution precipitation data derived from dynamical downscaling using the WRF model for the Heihe River Basin, northwest China

    Science.gov (United States)

    Zhang, Xuezhen; Xiong, Zhe; Zheng, Jingyun; Ge, Quansheng

    2018-02-01

    The community of climate change impact assessments and adaptations research needs regional high-resolution (spatial) meteorological data. This study produced two downscaled precipitation datasets with spatial resolutions of as high as 3 km by 3 km for the Heihe River Basin (HRB) from 2011 to 2014 using the Weather Research and Forecast (WRF) model nested with Final Analysis (FNL) from the National Center for Environmental Prediction (NCEP) and ERA-Interim from the European Centre for Medium-Range Weather Forecasts (ECMWF) (hereafter referred to as FNLexp and ERAexp, respectively). Both of the downscaling simulations generally reproduced the observed spatial patterns of precipitation. However, users should keep in mind that the two downscaled datasets are not exactly the same in terms of observations. In comparison to the remote sensing-based estimation, the FNLexp produced a bias of heavy precipitation centers. In comparison to the ground gauge-based measurements, for the warm season (May to September), the ERAexp produced more precipitation (root-mean-square error (RMSE) = 295.4 mm, across the 43 sites) and more heavy rainfall days, while the FNLexp produced less precipitation (RMSE = 115.6 mm) and less heavy rainfall days. Both the ERAexp and FNLexp produced considerably more precipitation for the cold season (October to April) with RMSE values of 119.5 and 32.2 mm, respectively, and more heavy precipitation days. Along with simulating a higher number of heavy precipitation days, both the FNLexp and ERAexp also simulated stronger extreme precipitation. Sensitivity experiments show that the bias of these simulations is much more sensitive to micro-physical parameterizations than to the spatial resolution of topography data. For the HRB, application of the WSM3 scheme may improve the performance of the WRF model.

  20. The Disastrous Effects of Salt Dust Deposition on Cotton Leaf Photosynthesis and the Cell Physiological Properties in the Ebinur Basin in Northwest China

    Science.gov (United States)

    Abuduwaili, Jilili; Zhaoyong, Zhang; Feng qing, Jiang; Dong wei, Liu

    2015-01-01

    Salt dust in rump lake areas in arid regions has long been considered an extreme stressor for both native plants and crops. In recent years, research on the harmful effects of salt dust on native plants has been published by many scholars, but the effect on crops has been little studied. In this work, in order to determine the impact of salt dust storms on cotton, we simulated salt dust exposure of cotton leaves in Ebinur Basin in Northwest China, and measured the particle sizes and salt ions in the dust, and the photosynthesis, the structure and the cell physiological properties of the cotton leaves. (1) Analysis found that the salt ions and particle sizes in the salt dust used in the experiments were consistent with the natural salt dust and modeled the salt dust deposition on cotton leaves in this region. (2) The main salt cations on the surface and inside the cotton leaves were Na+, Ca2+, Cl- and SO42-, while the amounts of CO3- and HCO3- were low. From the analysis, we can order the quantity of the salt cations and anions ions present on the surface and inside the cotton leaves as Na+>Ca2+>Mg2+>K+ and Cl->SO42->HCO3->CO3-, respectively. Furthermore, the five salt dust treatment groups in terms of the total salt ions on both the surface and inside the cotton leaves were A(500g.m-2)>B(400g.m-2)>C(300g.m-2)>D(200g.m-2)>E(100g.m-2)>F(0g.m-2). (3)The salt dust that landed on the surface of the cotton leaves can significantly influence the photosynthetic traits of Pn, PE, Ci, Ti, Gs, Tr, WUE, Ls, φ, Amax, k and Rady of the cotton leaves. (4)Salt dust can significantly damage the physiological functions of the cotton leaves, resulting in a decrease in leaf chlorophyll and carotenoid content, and increasing cytoplasmic membrane permeability and malondialdehyde (MDA) content by increasing the soluble sugar and proline to adjust for the loss of the cell cytosol. This increases the activity of antioxidant enzymes to eliminate harmful materials, such as the intracellular

  1. Spatial-temporal variability of soil water content in a cropland-shelterbelt-desert site in an arid inland river basin of Northwest China

    Science.gov (United States)

    Shen, Qin; Gao, Guangyao; Hu, Wei; Fu, Bojie

    2016-09-01

    Knowledge of the spatial-temporal variability of soil water content (SWC) is critical for understanding a range of hydrological processes. In this study, the spatial variance and temporal stability of SWC were investigated in a cropland-shelterbelt-desert site at the oasis-desert ecotone in the middle of the Heihe River Basin, China. The SWC was measured on 65 occasions to a depth of 2.8 m at 45 locations during two growing seasons from 2012 to 2013. The standard deviation of the SWC versus the mean SWC exhibited a convex upward relationship in the shelterbelt with the greatest spatial variation at the SWC of around 22.0%, whereas a linearly increasing relationship was observed for the cropland, desert, and land use pattern. The standard deviation of the relative difference was positively linearly correlated with the SWC (p statistics of temporal stability of the SWC could be presented equally well with a low frequency of observation (30-day interval) as with a high frequency (5-day interval). Sampling frequency had little effect on the selection of the representative locations of the field mean SWC. This study provides useful information for designing the optimal strategy for sampling SWC at the oasis-desert ecotone in the arid inland river basin.

  2. A double-layer structure model of uranium-bearing horizon in inland basins of medium to big size, North-west China, and its significance in metallogenic potential assessment

    International Nuclear Information System (INIS)

    Wang Zhilong.

    1985-01-01

    This paper presents a double-layer structure model of uranium-bearing horizon, i.e. uranium-bearing horizon = source rock (arkose red beds) + uranium trap (grey beds favourable to uranium precipitation) in inland basins of medium to big size, North-west China. The mechanism of its formation is: during diagenetic-epigenetic processes resulted in arkose red bed formation, feldspar was hydromicatized, feldspar and quartz were replaced by authigenic hematite, goethite and hydrogoethite and became red. In such oxidation process, part of uranium in detritus of silicates such as feldspar, quartz etc. was mobilized and released, but the released uranium can not be precipitated because of the oxidation environment, and it can be diffused during diagenetic dehydration and then precipitated in nearby grey beds with low Eh together with uranium-bearing 'stagnant water' fixed in pores, forming economic uranium concentration. It is evident that uranium deposit could not be formed owing to uranium dispersion in the case of absence of certain pervious grey beds rich in reductants, although arkose red beds could provide sufficient uranium source. Therefore, only the two conditions existed simultaneously, could the uranium-bearing horizons be formed. The significance of the model for uranium prospecting are as follows: 1. Uranium source range is much expanded concerning uranium prospecting in sandstone. Except the source in basement of the basin and its margins, we must also pay attention to the overlying red beds, especially the arkose red beds in inland basin of medium to big size. 2. For the potential assessment of basin and the selection of potential area, the model is an important prospecting criterion. 3. If we apply the main criterion uranium-bearing horizon-arkose red beds well, the buried ore bodies can be found provided that arkose red beds were regarded as a significant criterion of uranium-bearing horizon

  3. The red bed period of geological history in northwest China and regional uranium mineralization

    International Nuclear Information System (INIS)

    Quan Zhigao; Zhou Qiaosheng; Zhang Jinbiao.

    1990-01-01

    This paper clarifies that uranium mineralization temporally occurs in the period of regional tension and red beds and spatially belongs to rich uranium geological body and overlapped area of downfaulted red basin by comprehensively analysing the geological development history in Northwest China, regional red beds and uranium mineralization

  4. Combined multivariate statistical techniques, Water Pollution Index (WPI and Daniel Trend Test methods to evaluate temporal and spatial variations and trends of water quality at Shanchong River in the Northwest Basin of Lake Fuxian, China.

    Directory of Open Access Journals (Sweden)

    Quan Wang

    Full Text Available Understanding spatial and temporal variations in river water quality and quantitatively evaluating the trend of changes are important in order to study and efficiently manage water resources. In this study, an analysis of Water Pollution Index (WPI, Daniel Trend Test, Cluster Analysis and Discriminant Analysis are applied as an integrated approach to quantitatively explore the spatial and temporal variations and the latent sources of water pollution in the Shanchong River basin, Northwest Basin of Lake Fuxian, China. We group all field surveys into 2 clusters (dry season and rainy season. Moreover, 14 sampling sites have been grouped into 3 clusters for the rainy season (highly polluted, moderately polluted and less polluted sites and 2 clusters for the dry season (highly polluted and less polluted sites based on their similarities and the level of pollution during the two seasons. The results show that the main trend of pollution was aggravated during the transition from the dry to the rainy season. The Water Pollution Index of Total Nitrogen is the highest of all pollution parameters, whereas the Chemical Oxygen Demand (Chromium is the lowest. Our results also show that the main sources of pollution are farming activities alongside the Shanchong River, soil erosion and fish culture at Shanchong River reservoir area and domestic sewage from scattered rural residential area. Our results suggest that strategies to prevent water pollutionat the Shanchong River basin need to focus on non-point pollution control by employing appropriate fertilizer formulas in farming, and take the measures of soil and water conservation at Shanchong reservoir area, and purifying sewage from scattered villages.

  5. Combined multivariate statistical techniques, Water Pollution Index (WPI) and Daniel Trend Test methods to evaluate temporal and spatial variations and trends of water quality at Shanchong River in the Northwest Basin of Lake Fuxian, China.

    Science.gov (United States)

    Wang, Quan; Wu, Xianhua; Zhao, Bin; Qin, Jie; Peng, Tingchun

    2015-01-01

    Understanding spatial and temporal variations in river water quality and quantitatively evaluating the trend of changes are important in order to study and efficiently manage water resources. In this study, an analysis of Water Pollution Index (WPI), Daniel Trend Test, Cluster Analysis and Discriminant Analysis are applied as an integrated approach to quantitatively explore the spatial and temporal variations and the latent sources of water pollution in the Shanchong River basin, Northwest Basin of Lake Fuxian, China. We group all field surveys into 2 clusters (dry season and rainy season). Moreover, 14 sampling sites have been grouped into 3 clusters for the rainy season (highly polluted, moderately polluted and less polluted sites) and 2 clusters for the dry season (highly polluted and less polluted sites) based on their similarities and the level of pollution during the two seasons. The results show that the main trend of pollution was aggravated during the transition from the dry to the rainy season. The Water Pollution Index of Total Nitrogen is the highest of all pollution parameters, whereas the Chemical Oxygen Demand (Chromium) is the lowest. Our results also show that the main sources of pollution are farming activities alongside the Shanchong River, soil erosion and fish culture at Shanchong River reservoir area and domestic sewage from scattered rural residential area. Our results suggest that strategies to prevent water pollutionat the Shanchong River basin need to focus on non-point pollution control by employing appropriate fertilizer formulas in farming, and take the measures of soil and water conservation at Shanchong reservoir area, and purifying sewage from scattered villages.

  6. Combined Multivariate Statistical Techniques, Water Pollution Index (WPI) and Daniel Trend Test Methods to Evaluate Temporal and Spatial Variations and Trends of Water Quality at Shanchong River in the Northwest Basin of Lake Fuxian, China

    Science.gov (United States)

    Wang, Quan; Wu, Xianhua; Zhao, Bin; Qin, Jie; Peng, Tingchun

    2015-01-01

    Understanding spatial and temporal variations in river water quality and quantitatively evaluating the trend of changes are important in order to study and efficiently manage water resources. In this study, an analysis of Water Pollution Index (WPI), Daniel Trend Test, Cluster Analysis and Discriminant Analysis are applied as an integrated approach to quantitatively explore the spatial and temporal variations and the latent sources of water pollution in the Shanchong River basin, Northwest Basin of Lake Fuxian, China. We group all field surveys into 2 clusters (dry season and rainy season). Moreover, 14 sampling sites have been grouped into 3 clusters for the rainy season (highly polluted, moderately polluted and less polluted sites) and 2 clusters for the dry season (highly polluted and less polluted sites) based on their similarities and the level of pollution during the two seasons. The results show that the main trend of pollution was aggravated during the transition from the dry to the rainy season. The Water Pollution Index of Total Nitrogen is the highest of all pollution parameters, whereas the Chemical Oxygen Demand (Chromium) is the lowest. Our results also show that the main sources of pollution are farming activities alongside the Shanchong River, soil erosion and fish culture at Shanchong River reservoir area and domestic sewage from scattered rural residential area. Our results suggest that strategies to prevent water pollutionat the Shanchong River basin need to focus on non-point pollution control by employing appropriate fertilizer formulas in farming, and take the measures of soil and water conservation at Shanchong reservoir area, and purifying sewage from scattered villages. PMID:25837673

  7. Implementing Integrated River Basin Management in China

    NARCIS (Netherlands)

    Boekhorst, D.G.J. te; Smits, A.J.M.; Yu, X.; Lifeng, L.; Lei, G.; Zhang, C.

    2010-01-01

    This paper examines the role of the World Wildlife Fund for Nature China as policy entrepreneur in China. It illustrates the ways in which the World Wildlife Fund for Nature is active in promoting integrated river basin management in the Yangtze River basin and how the efforts at basin level are

  8. Implementing Integrated River Basin Management in China

    Directory of Open Access Journals (Sweden)

    Dorri G. J. te Boekhorst

    2010-06-01

    Full Text Available This paper examines the role of the World Wildlife Fund for Nature China as policy entrepreneur in China. It illustrates the ways in which the World Wildlife Fund for Nature is active in promoting integrated river basin management in the Yangtze River basin and how the efforts at basin level are matched with the advice of the China Council for International Cooperation on Environment and Development task force on integrated river basin management to the national government of China. This article demonstrates that the World Wildlife Fund for Nature uses various strategies of different types to support a transition process towards integrated river basin management. Successful deployment of these strategies for change in environmental policy requires special skills, actions, and attitudes on the part of the policy entrepreneur, especially in China, where the government has a dominant role regarding water management and the position of policy entrepeneurs is delicate.

  9. Comparison of Two Entropy Spectral Analysis Methods for Streamflow Forecasting in Northwest China

    Directory of Open Access Journals (Sweden)

    Zhenghong Zhou

    2017-11-01

    Full Text Available Monthly streamflow has elements of stochasticity, seasonality, and periodicity. Spectral analysis and time series analysis can, respectively, be employed to characterize the periodical pattern and the stochastic pattern. Both Burg entropy spectral analysis (BESA and configurational entropy spectral analysis (CESA combine spectral analysis and time series analysis. This study compared the predictive performances of BESA and CESA for monthly streamflow forecasting in six basins in Northwest China. Four criteria were selected to evaluate the performances of these two entropy spectral analyses: relative error (RE, root mean square error (RMSE, coefficient of determination (R2, and Nash–Sutcliffe efficiency coefficient (NSE. It was found that in Northwest China, both BESA and CESA forecasted monthly streamflow well with strong correlation. The forecast accuracy of BESA is higher than CESA. For the streamflow with weak correlation, the conclusion is the opposite.

  10. Progress and prospects of climate change impacts on hydrology in the arid region of northwest China.

    Science.gov (United States)

    Chen, Yaning; Li, Zhi; Fan, Yuting; Wang, Huaijun; Deng, Haijun

    2015-05-01

    The arid region of Northwest China, located in the central Asia, responds sensitively to global climate change. Based on the newest research results, this paper analyzes the impacts of climate change on hydrology and the water cycle in the arid region of Northwest China. The analysis results show that: (1) In the northwest arid region, temperature and precipitation experienced "sharply" increasing in the past 50 years. The precipitation trend changed in 1987, and since then has been in a state of high volatility, during the 21st century, the increasing rate of precipitation was diminished. Temperature experienced a "sharply" increase in 1997; however, this sharp increasing trend has turned to an apparent hiatus since the 21st century. The dramatic rise in winter temperatures in the northwest arid region is an important reason for the rise in the average annual temperature, and substantial increases in extreme winter minimum temperature play an important role in the rising average winter temperature; (2) There was a significant turning point in the change of pan evaporation in the northwest arid area in 1993, i.e., in which a significant decline reversed to a significant upward trend. In the 21st century, the negative effects of global warming and increasing levels of evaporation on the ecology of the northwest arid region have been highlighted; (3) Glacier change has a significant impact on hydrology in the northwest arid area, and glacier inflection points have appeared in some rivers. The melting water supply of the Tarim River Basin possesses a large portion of water supplies (about 50%). In the future, the amount of surface water will probably remain at a high state of fluctuation. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Community Service, Educational Performance and Social Responsibility in Northwest China

    Science.gov (United States)

    Luo, Renfu; Shi, Yaojiang; Zhang, Linxiu; Liu, Chengfang; Li, Hongbin; Rozelle, Scott; Sharbono, Brian

    2011-01-01

    The main goal of this paper is to analyse the effect of high school scholarships tied to community service on the development of secondary school students in Northwest China. Using data from three rounds of surveys of thousands of students in 298 classes in 75 high schools in Shaanxi province, the paper documents the implementation of the…

  12. Improving Knowledge about Children's Environmental Health in Northwest China.

    Science.gov (United States)

    Niu, Jingping; Qu, Qingshan; Li, Juansheng; Liu, Xingrong; Zhang, Benzhong; Li, Zhilan; Ding, Guowu; Sun, Yingbiao; Shi, Yanrong; Wan, Yaxiong; Hu, Xiaobin; Chen, Lung-Chi; Mendelsohn, Alan; Chen, Yu; Trasande, Leonardo

    2015-12-25

    The main purpose of this study was to identify policy maker opinions and attitudes towards children's environmental health (CEH), potential barriers to child-specific protective legislation and implementation in northwest China, and evaluate knowledge and attitudes about CEH before and after an educational conference. We conducted seventy-two interviews with regional officials, researchers and non-governmental organization representatives from five provinces, and surveyed participants (forty-seven) before and after an educational conference in northwest China about CEH. Interviews identified general consensus among participants of the adverse effects of air pollution on children, yet few participants knew of policies to protect them. Barriers identified included limited funding and enforcement, weak regional governments and absence of child-specific policy-making. After the conference, substantially greater self-efficacy was identified for lead, mercury, air pollution and polychlorinated biphenyls (+0.57-0.72 on a 1-5 Likert scale, p = 0.002-0.013), and the scientific knowledge for the role of environment in children's health (+0.58, p = 0.015), and health care provider control (+0.52, p = 0.025) were rated more strongly. We conclude that policy makers in Northwest China appreciate that children are uniquely vulnerable, though additional regulations are needed to account for that vulnerability. Further research should examine effectiveness of the intervention on a larger scale and scope, and evaluate the usefulness of such interventions in translating research into improved care/reduced exposure to environmental hazards.

  13. [Ecological and economic harmony evaluation and spatial evolution of the Hexi corridor, northwest China].

    Science.gov (United States)

    Liu, Hai-long; Shi, Pei-ji; Li, Sheng-mei; Tong, Hua-li; Nie, Xiao-ying; Wei, Wei

    2014-12-01

    The relationship between economic development and environment and the evolution characteristics of spatial pattern in Hexi Corridor of Northwest China were analyzed based on Landsat images in 1985, 1995, 2000 and 2011 with twenty counties in Hexi Corridor chosen as the basic research units. The ecological economic harmony during 1985-2011 was estimated according to ESV (ecosystem services value) and EEH (ecological and economic harmony) index with the ecosystem services value estimation methods. The results showed that the land type of the study area dramatically changed during the study period, the grassland decreased badly, and the construction land and cultivated land increased quickly. The ESV showed an overall downward trend, especially in the Shiyang River basin and the middle of Heihe River. The ESV in the Shule River basin in this period. After 2000, the economic growth speeded up visibly in the study area. The economic development concentrated in the resource-based cities and regional central cities, and declined from the center of corridor to the both sides. The ecological-economic relation in Hexi Corridor experienced a transformation of "preliminary deterioration--further deterioration--low grade coordination". The EEH had large changes in the Shiyang River basin and the middle of Heihe River, which experienced a transformation of "conflict--more conflicts--less conflicts", however, there was little change in Shule River basin. The development mode and the comprehensive reclamation of Shiyang River basin and Heihe River basin had a significant influence on the regional ecological and economic harmony.

  14. Advances on application of remote sensing technology to uranium prospecting in northwest of China

    International Nuclear Information System (INIS)

    Ye Fawang; Liu Dechang; Zhao Yingjun; Zhang Jielin; Fang Maolong

    2012-01-01

    Some advances on application of remote sensing technology to uranium prospecting in northwest of China since 21st century are presented in this paper. They included: (1) application of ETM multi-spectral remote sensing technology to identify the sandstone-type uranium ore-controlling structure in north of Ordos Basin and investigate the uranium metallogenetic geological conditions in Qiangtang Basin, Tibet, (2) application of ASTER multi-spectral and QuickBird high spatial resolution remote sensing technology to extract and analyze the oil-gas reduced alteration in Bashibulake uranium ore district, Xinjiang, (3) discovery of Salamubulake uranium metallogenetic belt in Keping, Xinjiang, using ASTER multi-spectral, QuickBird high spatial resolution, and CASI/SASI airborne hyper-spectral remote sensing comprehensively, and (4) application of CASI/SASI airborne hyper-spectral remote sensing technology to extract volcanicrock type uranium mineralization alteration in Baiyanghe area, Xinjiang. These application advances show the good application effects of remote sensing technology to uranium exploration in northwest of China, which provides important references for making further uranium prospecting using remote sensing technology. (authors)

  15. Exiled by Definition:The Salar of Northwest China

    Directory of Open Access Journals (Sweden)

    David SG Goodman

    2005-03-01

    Full Text Available The reform of state socialism came relatively late to Qinghai Province in the Northwest of the People’s Republic of China. One of Qinghai’s most dynamic groups in the social leadership of reform has been the Salar. The Salar were one of the officially recognized nationalities identified in the People’s Republic of China during the 1950s. A relatively small group of some 100,000 currently live along the upper reaches of the Yellow River, on the borders of Qinghai and Gansu Provinces. The Salar are characterised by their commitment to both Islam and China, and by their belief that they live in permanent exile, though there is considerable uncertainty about their origins. The evidence of recent research in Qinghai suggests the perspective of being Chinese citizens, yet a people in exile, significantly shapes recent Salar social and economic activism.

  16. The early-stage structural evolution of the Barmer Basin rift, Rajasthan, northwest India

    OpenAIRE

    Bladon, Andrew John

    2015-01-01

    The structural evolution of the Barmer Basin and the context of the rift within the northwest Indian region are poorly understood, despite being a prolific hydrocarbon province. In this work an integrated basin analysis is presented covering the outcrop-, seismic-, and lithosphere-scales. The early-stage structural evolution and the origin of poorly understood structural complications in the Barmer Basin subsurface are assessed. Subsequently, the findings are placed within the wider context o...

  17. The Local Residents’ Concerns about Environmental Issues in Northwest China

    Directory of Open Access Journals (Sweden)

    Fanus A. Aregay

    2016-03-01

    Full Text Available This paper analyzes public awareness and perception about current issues of environmental and water resources in China in comparison to the socio-economic issues. The ranking, Likert scale, and ordered logit analysis were applied to data from 1773 sample residents in northwest China. The results show that the residents rank the degradation of the ecological environment and water resources as the most important issue, and education, political involvement, gender, employment, and residential location play significant roles in explaining the observed differences in concern. Of the possible environmental and water resource restoration policies, residents ranked water quantity and quality, agricultural and industrial water use, erosion control, vegetation restoration, wildlife habitat, animal brooding and migration services, biodiversity landscape, and eco-tourism from one to nine in order of importance, respectively. The results are relevant for policymaking and imply that environmental restoration is a high public demand. Welfare gains from investments in it would be higher or equal to gains from other socio-economic and livelihood activities. Thus, public policies must emphasize restoring and maintaining a sustainable ecological environment.

  18. Preliminary site characterization at Beishan northwest China-A potential site for China's high-level radioactive waste repository

    International Nuclear Information System (INIS)

    Wang Ju; Su Rui; Xue Weiming; Zheng Hualing

    2004-01-01

    Chinese nuclear power plants,radioactive waste and radioactive waste disposal are introduced. Beishan region (Gansu province,Northwest China)for high-level radioactive waste repository and preliminary site characterization are also introduced. (Zhang chao)

  19. Hepatitis B virus genotypes and evolutionary profiles from blood donors from the northwest region of China

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2009-11-01

    Full Text Available Abstract Hepatitis B virus (HBV is prevalent in China and screening of blood donors is mandatory. Up to now, ELISA has been universally used by the China blood bank. However, this strategy has sometimes failed due to the high frequency of nucleoside acid mutations. Understanding HBV evolution and strain diversity could help devise a better screening system for blood donors. However, this kind of information in China, especially in the northwest region, is lacking. In the present study, serological markers and the HBV DNA load of 11 samples from blood donor candidates from northwest China were determined. The HBV strains were most clustered into B and C genotypes and could not be clustered into similar types from reference sequences. Subsequent testing showed liver function impairment and increasing virus load in the positive donors. This HBV evolutionary data for China will allow for better ELISA and NAT screening efficiency in the blood bank of China, especially in the northwest region.

  20. Evaluation of mulched drip irrigation for cotton in arid Northwest China

    NARCIS (Netherlands)

    Wang, Z.; Jin, M.; Simunek, J.; van Genuchten, M.T.

    2014-01-01

    Field experiments were conducted in arid Southern Xinjiang, Northwest China, for 3 years to evaluate sustainable irrigation regimes for cotton. The experiments involved mulched drip irrigation during the growing season and flood irrigation afterward. The drip irrigation experiments included control

  1. Extensive genetic divergence among Diptychus maculatus populations in northwest China

    Science.gov (United States)

    Meng, Wei; Yang, Tianyan; Hai, Sa; Ma, Yanwu; Cai, Lingang; Ma, Xufa; Gao, Tianxiang; Guo, Yan

    2015-05-01

    D. maculates is a kind of specialized Schizothoracinae fish has been locally listed as a protected animal in Xinjiang Province, China. Ili River located in north of Tianshan Mountain and Tarim River located in north of Qinghai-Tibetan Plateau were two main distribution areas of this fish. To investigate the genetic diversity and genetic structure of D. maculates, four populations from Tarim River system and two populations from Ili River system were collected in this study. A 570-bp sequence of the control region was obtained for 105 specimens. Twenty-four haplotypes were detected from six populations, only Kunes River population and Kashi River population shared haplotypes with each other. For all the populations examined, the haplotype diversity ( h) was 0.904 8±0.012 6, nucleotide diversity (π) was 0.027 9±0.013 9, and the average number of pairwise nucleotide differences ( k) was 15.878 3±7.139 1. The analysis of molecular variance (AMOVA) showed that 86.31% of the total genetic variation was apportioned among populations, and the variation within sampled populations was 13.69%. Genetic differences among sampled populations were highly significant. F st statistical test indicated that all populations were significantly divergent from each other ( P<0.01). The largest F st value was between Yurungkash River population and Muzat River population, while the smallest F st value was between Kunes River population and Kashi River population. NJ phylogenetic tree of D-loop haplotypes revealed two main clades. The neutrality test and mismatch distribution analysis suggested that the fish had went through a recent population expansion. The uplift of Tianshan Mountain and movement of Qinghai-Tibetan Plateau might contribute to the wide genetic divergence of D. maculates in northwest China.

  2. [Population difference of polypores in northwest and southeast of China].

    Science.gov (United States)

    Wang, Xiao-yan; Wei, Yu-lian

    2015-10-01

    Polypores are an important group of wood-rotting fungi and play a key role in decomposing wood in the forest ecosystem. Based on field investigations and laboratory analysis, fungal flora and diversity composition of polypores in Tianshan Moutains, Qilian Mountains, Baotianman Nature Reserve and Wuyi Mountains were analyzed. In total, 72 polypore species were found in Tianshan Mountains, 99 in Qilian Mountains, 124 in Baotianman Nature Reserve and 156 in Wuyi Mountains. There were fourteen common species in the four zones. The biogeography could be divided into 4 groups at genera level of the four zones, the important elements were North temperate element and cosmopolitan element, and floristic analysis showed a distinct north temperate character. The proportion of white rot polypores in the four zones increased from northwest to southeast of China, while the proportion of brown rot polypores decreased. Polypores preferentially grew on angiosperm trees compared to gymnosperm trees. Among the four zones, polypores in Baotianman had the highest proportion of species living on angiosperm trees. Rare and threatened species in Tianshan Mountains and Qilian Mountains were mainly found on conifer trees, while in the other two zones, most rare and threatened species were found on broadleaf trees. Generally, the distinctions of these four areas were mainly affected by the forest type.

  3. Pulsed strain release on the Altyn Tagh fault, northwest China

    Science.gov (United States)

    Gold, Ryan D.; Cowgill, Eric; Arrowsmith, J. Ramón; Friedrich, Anke M.

    2017-01-01

    Earthquake recurrence models assume that major surface-rupturing earthquakes are followed by periods of reduced rupture probability as stress rebuilds. Although purely periodic, time- or slip-predictable rupture models are known to be oversimplifications, a paucity of long records of fault slip clouds understanding of fault behavior and earthquake recurrence over multiple ruptures. Here, we report a 16 kyr history of fault slip—including a pulse of accelerated slip from 6.4 to 6.0 ka—determined using a Monte Carlo analysis of well-dated offset landforms along the central Altyn Tagh strike-slip fault (ATF) in northwest China. This pulse punctuates a median rate of 8.1+1.2/−0.9 mm/a and likely resulted from either a flurry of temporally clustered ∼Mw 7.5 ground-rupturing earthquakes or a single large >Mw 8.2 earthquake. The clustered earthquake scenario implies rapid re-rupture of a fault reach >195 km long and indicates decoupled rates of elastic strain energy accumulation versus dissipation, conceptualized as a crustal stress battery. If the pulse reflects a single event, slip-magnitude scaling implies that it ruptured much of the ATF with slip similar to, or exceeding, the largest documented historical ruptures. Both scenarios indicate fault rupture behavior that deviates from classic time- or slip-predictable models.

  4. Heavy metal pollution assessment, source identification, and health risk evaluation in Aibi Lake of northwest China.

    Science.gov (United States)

    Zhaoyong, Zhang; Xiaodong, Yang; Shengtian, Yang

    2018-01-08

    This study sought to analyze heavy metal (Pb, Zn, Cu, Ni, Mn, and Fe) pollution status in the waters of Aibi Lake in northwest China through the use of an applied comprehensive pollution index, health risk model, and multivariate statistical analyses in combination with the lake's land use types. Results showed that (1) the maximum (average) values of the heavy metals Pb, Zn, Cu, Ni, Mn, and Fe were 0.0644 (0.0123), 0.0006 (0.0002), 0.0009 (0.0032), 0.1235 (0.0242), 0.0061 (0.0025), and 0.0222 (0.0080) μg/L, respectively. Among these, in all the samples, Pb and Ni exceeded the standard and acceptable values put forth by the World Health Organization by 21.13 and 25.67%, respectively. Ni also exceeded (30.16%) the third grade of the Environmental Quality Standards for Surface Water of China. The levels of the six heavy metals were all within the fishery and irrigation water quality standard ranges in China. (2) The average values for single pollution index of heavy metals Pb, Zn, Cu, Ni, Mn, and Fe were 1.000, 0.0006, 0.0009, 3.000, 0.060, and 0.070, respectively, among which Ni levels indicated moderate to significant pollution, while others indicated healthy levels. (3) Health risk evaluation showed that the R n values for Pb, Zn, Cu, Mn, and Fe were 1.8 × 10 -4 , 5.33 × 10 -9 , 4.80 × 10 -7 , 1.08 × 10 -6 , and 2.51 × 10 -7  a -1 , respectively, of which, in all samples, Pb and Ni contents all exceeded the maximum acceptable risk levels according to the International Commission on Radiological Protection (ICRP) as well as the U.S. Environment Protection Agency. (4) Combining with multivariate statistical analyses along with the land use distribution within the lake basin, Pb, Zn, Cu, Ni, and Mn were mainly influenced by the agriculture production and emission from urban lives and traffics, and Fe mainly originated from the natural environment. The results of this research can provide reference values for heavy metal pollution

  5. Quaternary tectonic evolution of the Pamir-Tian Shan convergence zone, Northwest China

    Science.gov (United States)

    Thompson Jobe, Jessica Ann; Li, Tao; Chen, Jie; Burbank, Douglas W.; Bufe, Aaron

    2017-12-01

    The Pamir-Tian Shan collision zone in the western Tarim Basin, northwest China, formed from rapid and ongoing convergence in response to the Indo-Eurasian collision. The arid landscape preserves suites of fluvial terraces crossing structures active since the late Neogene that create fault and fold scarps recording Quaternary deformation. Using geologic and geomorphic mapping, differential GPS surveys of deformed terraces, and optically stimulated luminescence dating, we create a synthesis of the active structures that delineate the timing, rate, and migration of Quaternary deformation during ongoing convergence. New deformation rates on eight faults and folds, when combined with previous studies, highlight the spatial and temporal patterns of deformation within the Pamir-Tian Shan convergence zone during the Quaternary. Terraces spanning 130 to 8 ka record deformation rates between 0.1 and 5.6 mm/yr on individual structures. In the westernmost Tarim Basin, where the Pamir and Tian Shan are already juxtaposed, the fastest rates occur on actively deforming structures at the interface of the Pamir-Tian Shan orogens. Farther east, as the separation between the Pamir-Tian Shan orogens increases, the deformation has not been concentrated on a single structure, but rather has been concurrently distributed across a zone of faults and folds in the Kashi-Atushi fold-and-thrust belt and along the NE Pamir margin, where shortening rates vary on individual structures during the Quaternary. Although numerous structures accommodate the shortening and the locus of deformation shifts during the Quaternary, the total shortening across the western Tarim Basin has remained steady and approximately matches the current geodetic rate of 6-9 mm/yr.

  6. Water resource management in river oases along the Tarim River in North-West of China

    Science.gov (United States)

    Kliucininkaite, Lina; Disse, Markus

    2013-04-01

    Tarim River is one of the longest inland rivers in the world. It flows its water in the northern part of the Taklamakan desert in Xinjiang, North-west of China, which is a very hostile region due its climatic conditions and particularly due to low precipitation and very high evaporation rates. During the past five decades intensive exploitation of water resources, mainly by agricultural activities, has changed the temporal and spatial distribution of them and caused serious environmental problems in the Tarim River Basin. The support measures for oasis management along the Tarim River under climatic and societal changes became the overarching goal of this research. The temperature has risen by nearly 1° C over the past 50 years in the Tarim River Basin so more water was available in the mountainous areas of Xinjiang, leading to an increasing trend of the headstream discharges of the Tarim Basin. Aksu, Hotan and Yarkant Rivers are three tributaries of the Tarim River, as well as its main water suppliers. However, under the condition of water increase with the volume of 25×108 m3 in headstreams in recent 10 years, the water to the mainstream has increased less than 108 m3 (in Alar hydrological station), which is less than 3% of the increased water volume of runoff. Moreover, the region is one of the biggest cotton and other cash crops producers in China. In addition, expansion of urban and, in particular, of irrigation areas have caused higher water consumption at different parts of the river, leading to severe ecological effects on rural areas, especially in the lower reaches. Moreover, it also highly affects groundwater level and quality. The aim of this research is to support decision makers, planners and engineers to find right measures in the area for the further development of the region, as well as adaptation to changing climate. Different scenarios for water resource management, as well as water distribution and allocation in a more efficient and water

  7. Sources and characteristics of organochlorine pesticides in the soil and sediment along the Kaidu-Peacock River, Northwest of China

    Science.gov (United States)

    Chen, Wei; Qi, Shihua; Peng, Fei; Qu, Chengkai; Zhang, Yuan; Xing, Xinli; Zhang, Jiaquan

    2016-04-01

    Organochlorine pesticides (OCPs) are a sub-group of persistent organic pollutants (POPs), which have raised the concerns from researchers all around the world for several decades. But very little research has been conducted on POPs in the arid zone of Northwest China. More than 100 soil and sediment samples were collected from Kaidu-Peacock River of Xinjiang, Northwest of China, to investigate the organochlorine pesticides (OCPs) in this region analysed by the gas chromatograph equipped with a mass selective detector (GC-MSD). Our pre-study in 2006 (Chen et al. 2011) in the same region, showed that OCPs except o,p'-DDT were detected in sediments from the Peacock River. Similar results were found in the whole river catchment in this investigation. DDTs, HCHs, chlordanes and endosulfans were the dominant OCPs residual in the soil and sediments. This study confirmed that POPs, such as OCPs in this region were contributed to by both local emissions and long-term atmospheric transport and may pose risks to human health and the ecosystem. Chen, W., Jing, M., Bu, J., Ellis Burnet, J., Qi, S., Song, Q., Ke, Y., Miao, J., Liu, M. & Yang, C. (2011) Organochlorine pesticides in the surface water and sediments from the Peacock River Drainage Basin in Xinjiang, China: a study of an arid zone in Central Asia. Environmental Monitoring and Assessment, 177, 1-21.

  8. Assessing Dryland Ecosystem Services in Xinjiang, Northwest China

    Science.gov (United States)

    Siew, T. F.; Brauman, K. A.; Zuo, L.; Doll, P. M.

    2014-12-01

    Dryland ecosystems, including grassland, forest, and irrigated cropland, cover about 41% of earth's land area and are inhabited by over two billion people. In drylands, particularly arid and semiarid areas, the production of ecosystem services is primarily constrained by freshwater availability. Often, water allocated to production by one ecosystem or of one ecosystem service negatively impacts other ecosystems or ecosystem services (ESS). The challenge is to determine how much water should be allocated to which ecosystems (natural and manmade) such that multiple ESS are maximized, thus improving overall well-being. This strategic management decision must be supported by knowledge about spatial and temporal availability of water and its relationship to production (location and scale) of ESS that people receive. We assess the spatial and temporal relationships between water availability and ESS production in Xinjiang, Northwest China. We address four questions: (1) What services are produced by which ecosystems with water available? (2) Where are these services produced? (3) Who uses the services produced? (4) How the production of services changes with variability of water available? Using existing global, national, and regional spatial and statistical data, we assess food, fiber, livestock, and wood production as well as unique forest landscapes (as a proxy for aesthetic appreciation and habitats for unique animals and plants) and protection from dust storms. Irrigation is necessary for crop production in Xinjiang. The production of about 4.2 million tons of wheat and 500,000 tons of cotton requires more than 2 km3 of water each year. This is an important source of food and income for local residents, but the diverted water has negative and potentially costly impacts on downstream forests that potentially provide aesthetic services and protection from dust. Our analyses also show that cropland had increased by about 1.6 million ha from 1987 to 2010, while

  9. Petroleum system of Northwest Java basin based on gravity data analysis

    Science.gov (United States)

    Widianto, E.

    2018-01-01

    Energy management in the upstream oil and gas sector becomes very important for the country’s energy security. The renewal of energy resources and reserves becomes necessary and is a must. In the oil and gas industry, gravity data is usually used only for regional surveys, but with the development of instrumentation technology and gravity software development, this method can be used for assessing oil and gas survey stages from exploration to production. This study was conducted to evaluate aspects of petroleum system and exploration play concept in the part of Northwest Java Basin, covering source rock deposition regions (source kitchen area, migration direction), development of reservoirs, structural and stratigraphic trap, based on gravity data. This study uses data from Bouguer gravity anomaly map by filtering process to produce a residual map depicting sedimentation basin configuration. The mapping generated 20 sedimentary basins in Java Island with the total hydrocarbon resources of 113 BBOE (Billion Barrel of Oil Equivalent). The petroleum system analysis was conducted in the Northwest Basin section. The final map produced illustrates the condition of petroleum system and play concept that can be used as exploration direction, expectedly reducing the risk of drilling failure.

  10. Urbanization Process Monitoring in Northwest China based on DMSP/OLS Nighttime Light Data

    Science.gov (United States)

    Wang, K.; Bai, L. Y.; Feng, J. Z.

    2017-02-01

    In recent years, the DMSP/OLS nighttime light data have been widely applied to various fields such as monitoring and evaluation of urbanization, estimation of social economy, economical environment and health effects, hazards analysis, and fisheries research. The general urbanized level in China has rapidly developed since the 1990s, and the cities in northwest China, which were important population centres of the ancient silk road, have also been developed in a high speed thanks to China’s national strategy of Western Development. Given the Xinjiang autonomous region as a core area of One Belt and One Road, it is very necessary to study the urbanization processes and changes of its urban system and the whole northwest region of China. In this paper, we extracted built-up areas of the cities in northwest China in 1992, 1997, 2002, 2007, and 2012, evaluated urban expansion and spatial pattern through appropriate indexes, and also quantitatively analyzed the urbanized level of each city. The results showed that the cities in northwest China generally presented high strong and rapid expansion, but there were some large differences among cities. Urban expansion forms alternate with exterior expansion and interior filling, in general, the cities externally expandedafter 2002 and internally filledbefore 2002, meanwhile, there were a high positive correlation between urban built-up areas and population growth in Xinjiang autonomous.

  11. Changes and Relationships of Climatic and Hydrological Droughts in the Jialing River Basin, China.

    Science.gov (United States)

    Zeng, Xiaofan; Zhao, Na; Sun, Huaiwei; Ye, Lei; Zhai, Jianqing

    2015-01-01

    The comprehensive assessment of climatic and hydrological droughts in terms of their temporal and spatial evolutions is very important for water resources management and social development in the basin scale. To study the spatial and temporal changes of climatic and hydrological droughts and the relationships between them, the SPEI and SDI are adopted to assess the changes and the correlations of climatic and hydrological droughts by selecting the Jialing River basin, China as the research area. The SPEI and SDI at different time scales are assessed both at the entire Jialing River basin and at the regional levels of the three sub basins. The results show that the SPEI and SDI are very suitable for assessing the changes and relationships of climatic and hydrological droughts in large basins. Based on the assessment, for the Jialing River basin, climatic and hydrological droughts have the increasing tendency during recent several decades, and the increasing trend of climatic droughts is significant or extremely significant in the western and northern basin, while hydrological drought has a less significant increasing trend. Additionally, climatic and hydrological droughts tend to increase in the next few years. The results also show that on short time scales, climatic droughts have one or two months lag impact on hydrological droughts in the north-west area of the basin, and have one month lag impact in south-east area of the basin. The assessment of climatic and hydrological droughts based on the SPEI and SDI could be very useful for water resources management and climate change adaptation at large basin scale.

  12. Changes and Relationships of Climatic and Hydrological Droughts in the Jialing River Basin, China.

    Directory of Open Access Journals (Sweden)

    Xiaofan Zeng

    Full Text Available The comprehensive assessment of climatic and hydrological droughts in terms of their temporal and spatial evolutions is very important for water resources management and social development in the basin scale. To study the spatial and temporal changes of climatic and hydrological droughts and the relationships between them, the SPEI and SDI are adopted to assess the changes and the correlations of climatic and hydrological droughts by selecting the Jialing River basin, China as the research area. The SPEI and SDI at different time scales are assessed both at the entire Jialing River basin and at the regional levels of the three sub basins. The results show that the SPEI and SDI are very suitable for assessing the changes and relationships of climatic and hydrological droughts in large basins. Based on the assessment, for the Jialing River basin, climatic and hydrological droughts have the increasing tendency during recent several decades, and the increasing trend of climatic droughts is significant or extremely significant in the western and northern basin, while hydrological drought has a less significant increasing trend. Additionally, climatic and hydrological droughts tend to increase in the next few years. The results also show that on short time scales, climatic droughts have one or two months lag impact on hydrological droughts in the north-west area of the basin, and have one month lag impact in south-east area of the basin. The assessment of climatic and hydrological droughts based on the SPEI and SDI could be very useful for water resources management and climate change adaptation at large basin scale.

  13. Hydrocarbon seeps in petroliferous basins in China: A first inventory

    Science.gov (United States)

    Zheng, Guodong; Xu, Wang; Etiope, Giuseppe; Ma, Xiangxian; Liang, Shouyun; Fan, Qiaohui; Sajjad, Wasim; Li, Yang

    2018-01-01

    Natural hydrocarbon seepage is a widespread phenomenon in sedimentary basins, with important implications in petroleum exploration and emission of greenhouse gases to the atmosphere. China has vast petroleum (oil and gas) bearing sedimentary basins, but hydrocarbon seepage has rarely been the object of systematic studies and measurements. Based on the available Chinese literature, we report a first inventory of 932 hydrocarbon seeps or seepage zones (710 onshore seeps and 222 offshore seeps), including 81 mud volcanoes, 449 oil seeps, 215 gas seeps, and 187 solid seeps (bitumen outcrops). The seeps are located within the main 20 Mesozoic-Cenozoic petroliferous sedimentary basins, especially along the marginal, regional and local faults. The type of manifestations (oil, gas or mud volcano) reflects the type and maturity of the subsurface petroleum system and the sedimentary conditions of the basin. Oil seeps are particularly abundant in the Junggar Basin. Gas seeps mostly developed in the Lunpola Basin, in smaller basins of the eastern Guizhou and Yunnan provinces, onshore Taiwan and in the offshore Yinggehai Basin. Mud volcanoes developed in basins (Junggar, Qaidam, Qiangtang, onshore and offshore Taiwan) that experienced rapid sedimentation, which induced gravitative instability of shales and diapirism. In comparison to available global onshore seep data-bases, China results to be the country with the highest number of seeps in the world. The massive gas seepage in China could represent a considerable natural source of methane to the atmosphere, and a key process that may drive future hydrocarbon exploration.

  14. Groundwater quota versus tiered groundwater pricing : two cases of groundwater management in north-west China

    NARCIS (Netherlands)

    Aarnoudse, Eefje; Qu, Wei; Bluemling, B.; Herzfeld, Thomas

    2017-01-01

    Difficulties in monitoring groundwater extraction cause groundwater regulations to fail worldwide. In two counties in north-west China local water authorities have installed smart card machines to monitor and regulate farmers’ groundwater use. Data from a household survey and in-depth interviews are

  15. Relations between red beds times and uranic mineralization at the area of north-west China, Shaanxi and Inner Mongolia

    International Nuclear Information System (INIS)

    Zhou Qiaosheng; Quan Zhigao

    1989-04-01

    Rad beds played an important role in the uranic mineralization. After analyzing the geological evolution in North-West China, Saanxi and Inner Mongolia the red beds is divided into six periods. The evolution rules at each period are studied. The authors found that the time of uranic mineralication and formation of red beds (basin) is simultaneously, the uranic deposits and red beds are accompanying minerals in all places existing deposits. Uranic mineralization is bound up with the continental red beds which was formed under dry and hot climate, but has no relations with the marine red beds. The place where the deposits exist, the red beds must exist, conversely it is not true. In the section, a big uranic deposit is generated only under or above the red beds. The relations between red beds and rich deposit are also explored. The mineralization theory and the model of uranic mineralization in red beds times are presented

  16. Enhancing Agro-pastoralist Livelihoods in Northwest Yunnan, China ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Northwest Yunnan province has a considerable ethnic minority (Tibetan) living mainly in the mountainous rural areas and managing complex, fragile production systems. People face problems related to lack of crop diversification, conflicts over resource use (grasslands, forests) and poor service provision (extension, credit).

  17. Early villages and prehistoric sites in the Abharroud Basin, northwest of the Iranian Central Plateau

    Directory of Open Access Journals (Sweden)

    Sajjad Alibaigi

    2012-12-01

    Full Text Available The Abharroud basin is an important region in archaeological studies of the northwestern outskirts of the central plateau, and the west and northwest of Iran. Considering its environmental capabilities and geographical location, studying the region can leads us to a better understanding of regional relations and also inter-regional interaction between the cultural-geographical regions. During the two seasons of archaeological survey, 257 archaeological sites were discovered, dating from the lower Palaeolithic to recent ages. Of these, 34 sites contained prehistoric remains. Most of the identified sites are the remains of scattered villages and seasonal camps in different areas of the basin, on the plain and also impassable heights.

  18. The Tarim Basin, NW China: formation and aspects of petroleum geology

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q.M.; Coward, M.P. (Imperial College of Science, Technology and Medicine, London (United Kingdom). Dept. of Geology); Nishidai, T. (Japex Geoscience Inst., Inc., Tokyo (Japan))

    1992-01-01

    The formation and evolution since the Sinian of the Tarim Basin, in Northwest China, are introduced in this paper, on the basis of a study of stratigraphical and sedimentary facies, and an analysis of structural features. Mechanisms of basin formation have varied throughout this time, caused by frequent tectonic movements along the southern margin of the Eurasian Plate. As regards petroleum geology, six structural units have been classified from a consideration of the distribution of major source-rock sequences. An overall evaluation is made concerning hydrocarbon exploration in the individual structural units. Moreover, a general review is presented regarding source rocks, hydrocarbon reservoirs, trap structures, sealing layers and hydrocarbon generation, as well as possible recent exploration successes. (author)

  19. Detecting Variation Trends of Temperature and Precipitation for the Dadu River Basin, China

    Directory of Open Access Journals (Sweden)

    Ying Wu

    2016-01-01

    Full Text Available This study analyzes the variation trends of temperature and precipitation in the Dadu River Basin of China based on observed records from fourteen meteorological stations. The magnitude of trends was estimated using Sen’s linear method while its statistical significance was evaluated using Mann-Kendall’s test. The results of analysis depict increase change from northwest to southeast of annual temperature and precipitation in space. In temporal scale, the annual temperature showed significant increase trend and the annual precipitation showed increase trend. For extreme indices, the trends for temperature are more consistent in the region compared to precipitation. This paper has practical meanings for an effective management of climate risk and provides a foundation for further study of hydrological situation in this river basin.

  20. How Universities Work: Understanding Higher Education Organization in Northwest China

    Science.gov (United States)

    Berger, Joseph B.; Hudson, Katherine E.; Ramirez, Gerardo Blanco

    2013-01-01

    This study explores models of educational management used in postsecondary institutions in the five northwestern provinces of the People's Republic of China (Gansu, Ningxia, Qinghai, Shaanxi, and Xinjiang). As higher education in the People's Republic of China expands and undergoes significant changes, a nuanced understanding of the organizational…

  1. Rifting to India-Asia Reactivation: Multi-phase Structural Evolution of the Barmer Basin, Rajasthan, northwest India

    Science.gov (United States)

    Kelly, M. J.; Bladon, A.; Clarke, S.; Najman, Y.; Copley, A.; Kloppenburg, A.

    2015-12-01

    The Barmer Basin, situated within the West Indian Rift System, is an intra-cratonic rift basin produced during Gondwana break-up. Despite being a prominent oil and gas province, the structural evolution and context of the rift within northwest India remains poorly understood. Substantial subsurface datasets acquired during hydrocarbon exploration provide an unrivalled tool to investigate the tectonic evolution of the Barmer Basin rift and northwest India during India-Asia collision. Here we present a structural analysis using seismic datasets to investigate Barmer Basin evolution and place findings within the context of northwest India development. Present day rift structural architectures result from superposition of two non-coaxial extensional events; an early mid-Cretaceous rift-oblique event (NW-SE), followed by a main Paleocene rifting phase (NE-SW). Three phases of fault reactivation follow rifting: A transpressive, Late Paleocene inversion along localised E-W and NNE-SSW-trending faults; a widespread Late Paleocene-Early Eocene inversion and Late Miocene-Present Day transpressive strike-slip faulting along NW-SE-trending faults and isolated inversion structures. A major Late Eocene-Miocene unconformity in the basin is also identified, approximately coeval with those identified within the Himalayan foreland basin, suggesting a common cause related to India-Asia collision, and calling into question previous explanations that are not compatible with spatial extension of the unconformity beyond the foreland basin. Although, relatively poorly age constrained, extensional and compressional events within the Barmer Basin can be correlated with regional tectonic processes including the fragmentation of Gondwana, the rapid migration of the Greater Indian continent, to subsequent collision with Asia. New insights into the Barmer Basin development have important implications not only for ongoing hydrocarbon exploration but the temporal evolution of northwest India.

  2. Assessment of Climate Change Effects on Water Resources in the Yellow River Basin, China

    Directory of Open Access Journals (Sweden)

    Zhiyong Wu

    2015-01-01

    Full Text Available The water resources in the Yellow River basin (YRB are vital to social and economic development in North and Northwest China. The basin has a marked continental monsoon climate and its water resources are especially vulnerable to climate change. Projected runoff in the basin for the period from 2001 to 2030 was simulated using the variable infiltration capacity (VIC macroscale hydrology model. VIC was first calibrated using observations and then was driven by the precipitation and temperature projected by the RegCM3 high-resolution regional climate model under the IPCC scenario A2. Results show that, under the scenario A2, the mean annual temperature of the basin could increase by 1.6°C, while mean annual precipitation could decrease by 2.6%. There could be an 11.6% reduction in annual runoff in the basin according to the VIC projection. However, there are marked regional variations in these climate change impacts. Reductions of 13.6%, 25.7%, and 24.6% could be expected in the regions of Hekouzhen to Longmen, Longmen to Sanmenxia, and Sanmenxia to Huayuankou, respectively. Our study suggests that the condition of water resources in the YRB could become more severe in the period from 2001 to 2030 under the scenario A2.

  3. Tectonic evolution and hydrocarbon accumulation in the Yabulai Basin, western China

    Science.gov (United States)

    Zheng, Min; Wu, Xiaozhi

    2014-05-01

    The Yabulai petroliferous basin is located at the north of Hexi Corridor, western China, striking NEE and covering an area of 1.5×104 km2. It is bounded on the south by Beidashan Mountain to the Chaoshui Basin, on the east by Bayanwulashan Mountain to the Bayanhaote Basin, and on the northwest by Yabulai Mountain to the Yingen-Ejinaqi Basin. It is a Meso-cenozoic compressive depression residual basin. In view of regional geotectonics, the Yabulai basin sits in the middle-southern transition belt of Arershan massif in North China Craton. Driven by Indosinian movement at the late Triassic, two near EW normal faults were developed under the regional extensional stress along the northern fringe of Beidashan Mountain and the southern fringe of Yabulai Mountain front in the Arershan massif, forming the embryonic form of the Yabulai rift lake basin. Since Yanshan period, the Yabulai basin evolved in two major stages: Jurassic rift lake basin and Cretaceous rift lake basin. During early Yanshan period, EW striking Yabulai tensional rift was formed. Its major controlling fault was Beidashan normal fault, and the depocenter was at the south of this basin. During middle Yanshan period, collision orogenesis led to sharp uplift at the north of this basin where the middle-lower Jurassic formations were intensely eroded. During late Yanshan period, the Alashan massif and its northern area covered in an extensional tectonic environment, and EW striking normal faults were generated at the Yabulai Mountain front. Such faults moved violently and subsided quickly to form a new EW striking extensional rift basin with the depocenter at the south of Yabulai Mountain. During Himalayan period, the Alashan massif remained at a SN horizontal compressional tectonic environment; under the compressional and strike slip actions, a NW striking and south dipping thrusting nappe structure was formed in the south of the Yabulai basin, which broke the Beidashan normal fault to provide the echelon

  4. Seismic site characterization of the Kastelli (Kissamos) Basin in northwest Crete (Greece): Assessments using ambient noise recordings

    OpenAIRE

    Moisidi, M; Vallianatos, F; Kershaw, S; Collins, P

    2015-01-01

    Crete is actively seismic and site response studies are needed for estimating local site conditions subjected to seismic activity. In order to collect basic data, we performed ambient noise recordings to estimate the site response of the surface and near subsurface structure of the small-scale Kastelli Basin in northwest Crete. The spatial horizontal to vertical spectral ratios (HVSR) resonance pattern of the investigated sites in the centre of the Basin consists of either one or two peaks di...

  5. STP K Basin Sludge Sample Archive at the Pacific Northwest National Laboratory FY2014

    Energy Technology Data Exchange (ETDEWEB)

    Fiskum, Sandra K.; Smoot, Margaret R.; Schmidt, Andrew J.

    2014-06-01

    The Pacific Northwest National Laboratory (PNNL) currently houses 88 samples (~10.5 kg) of K Basin sludge (81 wet and seven dry samples) on behalf of the Sludge Treatment Project (STP), which is managed for the U.S. Department of Energy (DOE) by the CH2M Hill Plateau Remediation Company (CHPRC). Selected samples are intended to serve, in part, as sentinels to enhance understanding of sludge properties after long-term storage, and thus enhance understanding of sludge behavior following transfer to sludge transfer and storage containers (STSCs) and storage at the Hanford 200 Area central plateau. In addition, remaining samples serve in contingency for future testing requirements. At PNNL, the samples are tracked and maintained under a prescriptive and disciplined monthly sample-monitoring program implemented by PNNL staff. This report updates the status of the K Basin archive sludge sample inventory to April 2014. The previous inventory status report, PNNL 22245 (Fiskum et al. 2013, limited distribution report), was issued in February of 2013. This update incorporates changes in the inventory related to repackaging of 17 samples under test instructions 52578 TI052, K Basin Sludge Sample Repackaging for Continued Long Term Storage, and 52578 TI053, K Basin Sludge Sample Repackaging Post-2014 Shear Strength Measurements. Note that shear strength measurement results acquired in 2014 are provided separately. Specifically, this report provides the following: • a description of the K Basin sludge sample archive program and the sample inventory • a summary and images of the samples that were repackaged in April 2014 • up-to-date images and plots of the settled density and water loss from all applicable samples in the inventory • updated sample pedigree charts, which provide a roadmap of the genesis and processing history of each sample in the inventory • occurrence and deficiency reports associated with sample storage and repackaging

  6. Association of obesity with socioeconomic status among adults of ages 18 to 80?years in rural Northwest China

    OpenAIRE

    Pei, Leilei; Cheng, Yue; Kang, Yijun; Yuan, Shuyi; Yan, Hong

    2015-01-01

    Background Understanding social disparities in obesity are presently an essential element in establishing public health priorities. However, the association between socioeconomic status (SES) and obesity has not been assessed in rural Northwest China. This study aims to explore the effect of SES on overweight/obesity and abdominal obesity by gender and age in rural Northwest China. Methods A total of 3030 participants between the ages of 18 to 80?years from rural Hanzhong, Shaanxi province, N...

  7. Understanding Educational Leadership in North-West China

    Science.gov (United States)

    Militello, Matthew; Berger, Joseph B.

    2010-01-01

    The purpose of this study was to develop greater depth of understanding regarding educational leadership development in the five north-western provinces (Shaanxi, Xinjiang, Gansu, Qinghai and Ningxia) of the People's Republic of China. The researchers used a mixed method approach of surveys and focus group interviews to gather data regarding the…

  8. Land tenure security and land investments in Northwest China

    NARCIS (Netherlands)

    Ma Xian lei, Xianlei; Heerink, N.; Ierland, van E.C.; Berg, van den M.; Shi, X.

    2013-01-01

    Purpose - The purpose of this paper is to examine the effect of perceived land tenure security in China on farmers' decisions to invest in relatively long-term land quality improvement measures, taking into account the potential endogeneity of tenure security. Design/methodology/approach – Data from

  9. Interdecadal Variability of Winter Precipitation in Northwest China and Its Association with the North Atlantic SST Change

    Science.gov (United States)

    Liantong, Zhou

    2017-04-01

    Winter precipitation in Northwest China experienced an obvious interdecadal increase around 1987. Consistent increase in winter precipitation occurred in Middle Asia. The present study investigates associated changes in atmospheric circulation and sea surface temperature (SST). Analyses show that winter water vapor flux and atmospheric circulation over the North Atlantic Ocean and Eurasia and SST in the North Atlantic Ocean were very different before and after 1987. During 1987-2008, a significant enhancement of tropospheric moisture convergence and ascending motion was observed over Northwest China and Middle Asia. This contributed to the increase of winter precipitation in Northwest China and Middle Asia. The wind difference field before and after 1986/87 features cyclones over Middle Asia and northern Atlantic Ocean and anticyclones over East Asia and southern Europe-northern Africa, signifying an obvious change in the Eurasian (EU) teleconnection pattern over middle latitudes of Eurasia. The results indicate that the Middle Asia and Northwest China were under the influence of enhanced westerlies from the North Atlantic Ocean that strengthened the water vapor transport to Middle Asia and Northwest China after 1987. Moreover, the interdecadal variability in the EU pattern is associated with the SST increase in the North Atlantic Ocean. Thus, the North Atlantic SST change is likely an important reason for the winter precipitation increase in Middle Asia and Northwest China.

  10. Quantitative Analysis and Comparison of BMI among Han, Tibetan, and Uygur University Students in Northwest China

    OpenAIRE

    Jingya, Bai; Ye, He; Jing, Wang; Xi, Huanjiu; Tao, Hai

    2013-01-01

    Objectives. To fully analyze and compare BMI among Han, Tibetan, and Uygur university students, to discuss the differences in their physical properties and physical health, and thus to provide some theoretical suggestions for the improvement of students’ physical health. Methods. The cross-sectional random cluster sampling was used to investigate 10103 Han, Tibetan, and Uygur university students, aged 20–24 in Northwest China, and their height and weight were measured to calculate BMI. The BM...

  11. Establishment and assessment of cataract surgery in Day-care Unit at northwest of China

    OpenAIRE

    Xiu-Li Zhang; Xing Yang; Juan-Juan Yang; Bao-Jian Yan; Jing-Ming Li; Cheng Pei; Li Qin

    2018-01-01

    AIM: To describe the protocol and economic cost of the Day-care Unit cataract surgery procedure in northwest of China.METHODS: Patients who received phacoemulcification and intraocular lens implantation in both Day-care Unit and regular Unit were recruited from January 2016 to December 2016. The baseline data and average cost were recorded and analyzed. Furthermore, satisfaction questionnaire of patients were collected.RESULTS: Patients with Day-care Unit showed shorter registration duration,...

  12. Extreme Precipitation Changes in the Semiarid Region of Xinjiang, Northwest China

    OpenAIRE

    Yanwei Zhang; Quansheng Ge; Minzhe Liu

    2015-01-01

    This study focuses on extreme precipitation changes in Xinjiang Province of Northwest China, which has experienced an increase in climate disasters in recent years. This paper investigates extreme precipitation events in Xinjiang, using 54 stations with daily precipitation records from the period 1961–2008. Different statistical tests and approaches were used to check the significance of trends of single and Xinjiang regionally aggregated precipitation series for intensity and in frequency. T...

  13. Detecting changes in future precipitation extremes over eight river basins in China using RegCM4 downscaling

    Science.gov (United States)

    Qin, Peihua; Xie, Zhenghui

    2016-06-01

    To detect the frequency and intensity of precipitation extremes in China for the middle 21st century, simulations were conducted with the regional climate model RegCM4 forced by the global climate model GFDL_ESM2M under the middle emission scenario (RCP4.5). Compared with observed precipitation extremes for the reference period from 1982 to 2001, RegCM4 generally performed better in most river basins of China relative to GFDL. In the future period 2032-2051, more wet extremes will occur relative to the present period in most study areas, especially in southeast China while significantly less dry extremes will occur in arid and semiarid areas in northwest China. In contrast, areas in northwest China showed an increase in the trend of dry extremes (CDD) and a decrease in the trend of wet extremes (R95p and Rx5day), which might result in more drought in the future. Finally, we discuss in detail the possible reason of these processes, such as zonal wind, vertical wind, and water vapor. In the Huaihe river basin (HU), reduced south winds in summer (June-August) and a decrease of the upward vertical p velocity cause less future precipitation and might lead to changes of extreme events. We also completed correlation analysis between the precipitation extreme indices and the climate factors and found that the precipitation extremes were more sensitive to the annual and seasonal mean precipitation, total water vapor, and upward vertical wind relative to the geopotential height and 2 m temperature over most river basins in China. Perhaps the changes of some wet extremes could be verified partly through changes of annual precipitation due to their high consistence.

  14. Distribution of Actual Evapotranspiration over Qaidam Basin, an Arid Area in China

    Directory of Open Access Journals (Sweden)

    Xiaomei Jin

    2013-12-01

    Full Text Available Evapotranspiration is a major loss flux of the water balance in arid and semi-arid areas. The estimation of actual evapotranspiration has significance for hydrological and environmental purposes. The Surface Energy Balance System (SEBS algorithm was applied to estimate actual evapotranspiration in the Qaidam Basin and its eight hydrological sub-regions, Northwest China. There were 3,036 cloud-free and atmospherically corrected MODIS satellite images from 2001 to 2011 used in the SEBS algorithm to determine the actual evapotranspiration. The result indicated that the estimated annual actual evapotranspiration of the basin increased with time and the value varied from 72.7 to 182.3 mm. SEBS estimates were 7.5% and 14.1% of observed pan evaporation over the western and eastern areas, respectively. The variation of SEBS actual evapotranspiration is influenced by climate factors, vegetation, net radiation, land cover type and water table depth. The analysis of the evaporative behavior of different land cover types in the basin presented that water bodies, marsh, and farmland had relatively higher mean actual evapotranspiration though these land cover types make up less than 3.5% of the total basin. Bare soil has very low evapotranspiration and covered almost 60% of the study area. The actual evapotranspiration was observed to be decreased with an increase of water table depth. Overall, the SEBS algorithm proved to be useful and has potential for estimating spatial actual evapotranspiration on a regional scale.

  15. Water Availability for Shale Gas Development in Sichuan Basin, China.

    Science.gov (United States)

    Yu, Mengjun; Weinthal, Erika; Patiño-Echeverri, Dalia; Deshusses, Marc A; Zou, Caineng; Ni, Yunyan; Vengosh, Avner

    2016-03-15

    Unconventional shale gas development holds promise for reducing the predominant consumption of coal and increasing the utilization of natural gas in China. While China possesses some of the most abundant technically recoverable shale gas resources in the world, water availability could still be a limiting factor for hydraulic fracturing operations, in addition to geological, infrastructural, and technological barriers. Here, we project the baseline water availability for the next 15 years in Sichuan Basin, one of the most promising shale gas basins in China. Our projection shows that continued water demand for the domestic sector in Sichuan Basin could result in high to extremely high water stress in certain areas. By simulating shale gas development and using information from current water use for hydraulic fracturing in Sichuan Basin (20,000-30,000 m(3) per well), we project that during the next decade water use for shale gas development could reach 20-30 million m(3)/year, when shale gas well development is projected to be most active. While this volume is negligible relative to the projected overall domestic water use of ∼36 billion m(3)/year, we posit that intensification of hydraulic fracturing and water use might compete with other water utilization in local water-stress areas in Sichuan Basin.

  16. Rabies Outbreaks and Vaccination in Domestic Camels and Cattle in Northwest China.

    Directory of Open Access Journals (Sweden)

    Ye Liu

    2016-09-01

    Full Text Available In contrast to many countries where rabies has been well controlled in humans and livestock, even in wildlife, rabies is still endemic in almost regions of China. In Northwest China, rabies transmitted by stray dogs and wild foxes has caused heavy economic losses to local herdsmen, as well as causing numbers of human cases. In this study, as part of an investigation of ways to prevent rabies epidemics in livestock, we report an analysis of domestic cattle and camel rabies cases in Ningxia Hui (NHAR and Inner Mongolia Autonomous Region (IMAR and the immune efficacy of canine inactivated rabies vaccines in these animals. We found that rabies viruses from these animals are closely related to dog-hosted China I and fox-associated China III lineages, respectively, indicating that the infections originated from two different sources (dogs and wild foxes. As well as the previously reported Arctic and Arctic-related China IV lineage in IMAR, at least three separate phylogenetic groups of rabies virus consistently exist and spread throughout Northwest China. Since there is no licensed oral vaccine for wild foxes and no inactivated vaccine for large livestock, local canine inactivated vaccine products were used for emergency immunization of beef and milk cattle and bactrian (two-humped camels in local farms. Compared with a single injection with one (low-efficacy or three doses (high-cost, a single injection of a double dose of canine vaccine provided low-price and convenience for local veterinarians while inducing levels of virus neutralizing antibodies indicative of protection against rabies for at least 1 year in the cattle and camels. However, licensed vaccines for wildlife and large domestic animals are still needed in China.

  17. Rabies Outbreaks and Vaccination in Domestic Camels and Cattle in Northwest China.

    Science.gov (United States)

    Liu, Ye; Zhang, He-Ping; Zhang, Shou-Feng; Wang, Jin-Xiang; Zhou, Hai-Ning; Zhang, Fei; Wang, Yu-Mei; Ma, Long; Li, Nan; Hu, Rong-Liang

    2016-09-01

    In contrast to many countries where rabies has been well controlled in humans and livestock, even in wildlife, rabies is still endemic in almost regions of China. In Northwest China, rabies transmitted by stray dogs and wild foxes has caused heavy economic losses to local herdsmen, as well as causing numbers of human cases. In this study, as part of an investigation of ways to prevent rabies epidemics in livestock, we report an analysis of domestic cattle and camel rabies cases in Ningxia Hui (NHAR) and Inner Mongolia Autonomous Region (IMAR) and the immune efficacy of canine inactivated rabies vaccines in these animals. We found that rabies viruses from these animals are closely related to dog-hosted China I and fox-associated China III lineages, respectively, indicating that the infections originated from two different sources (dogs and wild foxes). As well as the previously reported Arctic and Arctic-related China IV lineage in IMAR, at least three separate phylogenetic groups of rabies virus consistently exist and spread throughout Northwest China. Since there is no licensed oral vaccine for wild foxes and no inactivated vaccine for large livestock, local canine inactivated vaccine products were used for emergency immunization of beef and milk cattle and bactrian (two-humped) camels in local farms. Compared with a single injection with one (low-efficacy) or three doses (high-cost), a single injection of a double dose of canine vaccine provided low-price and convenience for local veterinarians while inducing levels of virus neutralizing antibodies indicative of protection against rabies for at least 1 year in the cattle and camels. However, licensed vaccines for wildlife and large domestic animals are still needed in China.

  18. Spatial Preference Heterogeneity for Integrated River Basin Management: The Case of the Shiyang River Basin, China

    Directory of Open Access Journals (Sweden)

    Fanus Asefaw Aregay

    2016-09-01

    Full Text Available Integrated river basin management (IRBM programs have been launched in most parts of China to ease escalating environmental degradation. Meanwhile, little is known about the benefits from and the support for these programs. This paper presents a case study of the preference heterogeneity for IRBM in the Shiyang River Basin, China, as measured by the Willingness to Pay (WTP, for a set of major restoration attributes. A discrete choice analysis of relevant restoration attributes was conducted. The results based on a sample of 1012 households in the whole basin show that, on average, there is significant support for integrated ecological restoration as indicated by significant WTP for all ecological attributes. However, residential location induced preference heterogeneities are prevalent. Generally, compared to upper-basin residents, middle sub-basin residents have lower mean WTP while lower sub-basin residents express higher mean WTP. The disparity in utility is partially explained by the difference in ecological and socio-economic status of the residents. In conclusion, estimating welfare benefit of IRBM projects based on sample responses from a specific sub-section of the basin only may either understate or overstate the welfare estimate.

  19. Genetic variation in yield and chemical composition of wide range of sorghum accessions grown in north-west China

    NARCIS (Netherlands)

    Wang, J.S.; Wang, M.L.; Spiertz, J.H.J.; Liu, Z.; Han, L.; Xie, G.H.

    2013-01-01

    Sorghum can be grown on marginal and waste lands as a versatile feedstock for biofuel production in the vast areas of north-west China. Fifty-six sorghum accessions were grown in 2009 at the experimental station of Xinjiang Agricultural University, located at Urumchi, Xinjiang, China. A total of 31

  20. Discrete wavelet transform-based investigation into the variability of standardized precipitation index in Northwest China during 1960-2014

    Science.gov (United States)

    Yang, Peng; Xia, Jun; Zhan, Chesheng; Zhang, Yongyong; Hu, Sheng

    2018-04-01

    In this study, the temporal variations of the standard precipitation index (SPI) were analyzed at different scales in Northwest China (NWC). Discrete wavelet transform (DWT) was used in conjunction with the Mann-Kendall (MK) test in this study. This study also investigated the relationships between original precipitation and different periodic components of SPI series with datasets spanning 55 years (1960-2014). The results showed that with the exception of the annual and summer SPI in the Inner Mongolia Inland Rivers Basin (IMIRB), spring SPI in the Qinghai Lake Rivers Basin (QLRB), and spring SPI in the Central Asia Rivers Basin (CARB), it had an increasing trend in other regions for other time series. In the spring, summer, and autumn series, though the MK trends test in most areas was at the insignificant level, they showed an increasing trend in precipitation. Meanwhile, the SPI series in most subbasins of NWC displayed a turning point in 1980-1990, with the significant increasing levels after 2000. Additionally, there was a significant difference between the trend of the original SPI series and the largest approximations. The annual and seasonal SPI series were composed of the short periodicities, which were less than a decade. The MK value would increase by adding the multiple D components (and approximations), and the MK value of the combined series was in harmony with that of the original series. Additionally, the major trend of the annual SPI in NWC was based on the four kinds of climate indices (e.g., Atlantic Oscillation [AO], North Atlantic Oscillation [NAO], Pacific Decadal Oscillation [PDO], and El Nino-Southern Oscillation index [ENSO/NINO]), especially the ENSO.

  1. Tree-ring reconstruction of streamflow in the Snare River Basin, Northwest Territories, Canada

    Science.gov (United States)

    Martin, J. P.; Pisaric, M. F.

    2017-12-01

    Drought is a component of many ecosystems in North America causing environmental and socioeconomical impacts. In the ongoing context of climatic and environmental changes, drought-related issues are becoming problematic in northern Canada, which have not been associated with drought-like conditions in the past. Dryer than average conditions threatens the energy security of northern canadian communities, since this region relies on the production of hydroelectricity as an energy source. In the North Slave Region of Northwest Territory (NWT), water levels and streamflows were significantly lower in 2014/2015. The Government of the NWT had to spend nearly $50 million to purchase diesel fuel to generate enough electricity to supplement the reduced power generation of the Snare River hydroelectric system, hence the need to better understand the multi-decadal variability in streamflow. The aims of this presentation are i) to present jack pine and white spruce tree-ring chronologies of Southern NWT; ii) to reconstruct past streamflow of the Snare River Basin; iii) to evaluate the frequency and magnitude of extreme drought conditions, and iv) to identify which large-scale atmospheric or oceanic patterns are teleconnected to regional hydraulic conditions. Preliminary results show that the growth of jack pine and white spruce populations is better correlated with precipitation and temperature, respectively, than hydraulic conditions. Nonetheless, we present a robust streamflow reconstruction of the Snare River that is well correlated with the summer North Atlantic Oscillation (NAO) index, albeit the strength of the correlation is non-stationary. Spectral analysis corroborate the synchronicity between negative NAO conditions and drought conditions. From an operational standpoint, considering that the general occurrence of positive/negative NAO can be predicted, it the hope of the authors that these results can facilitate energetic planning in the Northwest Territories through

  2. Microstructures in landslides in northwest China - Implications for creeping displacements?

    Science.gov (United States)

    Schäbitz, M.; Janssen, C.; Wenk, H.-R.; Wirth, R.; Schuck, B.; Wetzel, H.-U.; Meng, X.; Dresen, G.

    2018-01-01

    Microstructures, mineralogical composition and texture of selected landslide samples from three landslides in the southern part of the Gansu Province (China) were examined with optical microscopy, transmission electron microscopy (TEM), x-ray diffraction (XRD) and synchrotron x-ray diffraction measurements. Common sheet silicates are chlorite, illite, muscovite, kaolinite, pyrophyllite and dickite. Other minerals are quartz, calcite, dolomite and albite. In one sample, graphite and amorphous carbon were detected by TEM-EDX analyses and TEM high-angle annular dark-field images. The occurrence of graphite and pyrophyllite with very low friction coefficients in the gouge material of the Suoertou and Xieliupo landslides is particularly significant for reducing the frictional strength of the landslides. It is proposed that the landslides underwent comparable deformation processes as fault zones. The low friction coefficients provide strong evidence that slow-moving landsliding is controlled by the presence of weak minerals. In addition, TEM observations document that grain size reduction in clayey slip zone material was produced mainly by mechanical abrasion. For calcite and quartz, grain size reduction was attributed to both pressure solution and cataclasis. Therefore, besides landslide composition, the occurrence of ultrafine-grained slip zone material may also contribute to weakening processes of landslides. TEM images of slip-zone samples show both locally aligned clay particles, as well as kinked and folded sheet silicates, which are widely disseminated in the whole matrix. Small, newly formed clay particles have random orientations. Based on synchrotron x-ray diffraction measurements, the degree of preferred orientation of constituent sheet silicates in local shear zones of the Suoertou and Duang-He-Ba landslide is strong. This work is the first reported observation of well-oriented clay fabrics in landslides.

  3. The water footprint of hydraulic fracturing in Sichuan Basin, China.

    Science.gov (United States)

    Zou, Caineng; Ni, Yunyan; Li, Jian; Kondash, Andrew; Coyte, Rachel; Lauer, Nancy; Cui, Huiying; Liao, Fengrong; Vengosh, Avner

    2018-02-23

    Shale gas is likely to play a major role in China's transition away from coal. In addition to technological and infrastructural constraints, the main challenges to China's sustainable shale gas development are sufficient shale gas production, water availability, and adequate wastewater management. Here we present, for the first time, actual data of shale gas production and its water footprint from the Weiyuan gas field, one of the major gas fields in Sichuan Basin. We show that shale gas production rates during the first 12 months (24 million m 3 per well) are similar to gas production rates in U.S. shale basins. The amount of water used for hydraulic fracturing (34,000 m 3 per well) and the volume of flowback and produced (FP) water in the first 12 months (19,800 m 3 per well) in Sichuan Basin are also similar to the current water footprints of hydraulic fracturing in U.S. basins. We present salinity data of the FP water (5000 to 40,000 mgCl/L) in Sichuan Basin and the treatment operations, which include sedimentation, dilution with fresh water, and recycling of the FP water for hydraulic fracturing. We utilize the water use data, empirical decline rates of shale gas and FP water productions in Sichuan Basin to generate two prediction models for water use for hydraulic fracturing and FP water production upon achieving China's goals to generate 100 billion m 3 of shale gas by 2030. The first model utilizes the current water use and FP production data, and the second assumes a yearly 5% intensification of the hydraulic fracturing process. The predicted water use for hydraulic fracturing in 2030 (50-65 million m 3 per year), FP water production (50-55 million m 3 per year), and fresh water dilution of FP water (25 million m 3 per year) constitute a water footprint that is much smaller than current water consumption and wastewater generation for coal mining, but higher than those of conventional gas production in China. Given estimates

  4. Influence of climate change and human activity on water resources in arid region of Northwest China: An overview

    Directory of Open Access Journals (Sweden)

    Yu-Jie Wang

    2017-12-01

    Full Text Available This study reviews the latest progress in research on climate change and water resources in the arid region of Northwest China, analyzes the cause of water resource changes within the region from the perspective of climate change and human activities, and summarizes future likely changes in water resources and associated adaptation strategies. The research shows that the climate in the region has experienced warming and wetting with the most significant warming in winter and the highest increase in summer precipitation since 1961. Areas with the most significant warming trends include the Qaidam Basin, the Yili River Valley, and Tacheng. Spatially, the increasing trend in precipitation becomes increasingly significant from the southeast to the northwest, and northern Xinjiang experienced the highest increase. Studies have shown a decrease in headwater of Shiyang River because runoff is mainly based on precipitation which shows a decrease trend. But an increase in western rivers was observed such as Tarim River and Shule River as well as Heihe River due to rapid glacier shrinkage and snowmelt as well as precipitation increase in mountain area. Meanwhile unreasonable human activities resulted in decrease of runoff in the middle and lower reaches of Haihe River, Shiyang River and Kaidu River. Finally, recommendations for future studies are suggested that include characteristics of changes in extreme weather events and their impacts on water resources, projections of future climate and water resource changes, climate change attribution, the selection of adaptation strategies relating to climate change and social economic activities, and use of scientific methods to quantitatively determine water resource allocation.

  5. Hydroclimate temporal variability in a coastal Mediterranean watershed: the Tafna basin, North-West Algeria

    Science.gov (United States)

    Boulariah, Ouafik; Longobardi, Antonia; Meddi, Mohamed

    2017-04-01

    One of the major challenges scientists, practitioners and stakeholders are nowadays involved in, is to provide the worldwide population with reliable water supplies, protecting, at the same time, the freshwater ecosystems quality and quantity. Climate and land use changes undermine the balance between water demand and water availability, causing alteration of rivers flow regime. Knowledge of hydro-climate variables temporal and spatial variability is clearly helpful to plan drought and flood hazard mitigation strategies but also to adapt them to future environmental scenarios. The present study relates to the coastal semi-arid Tafna catchment, located in the North-West of Algeria, within the Mediterranean basin. The aim is the investigation of streamflow and rainfall indices temporal variability in six sub-basins of the large catchment Tafna, attempting to relate streamflow and rainfall changes. Rainfall and streamflow time series have been preliminary tested for data quality and homogeneity, through the coupled application of two-tailed t test, Pettitt test and Cumsum tests (significance level of 0.1, 0.05 and 0.01). Subsequently maximum annual daily rainfall and streamflow and average daily annual rainfall and streamflow time series have been derived and tested for temporal variability, through the application of the Mann Kendall and Sen's test. Overall maximum annual daily streamflow time series exhibit a negative trend which is however significant for only 30% of the station. Maximum annual daily rainfall also e exhibit a negative trend which is intend significant for the 80% of the stations. In the case of average daily annual streamflow and rainfall, the tendency for decrease in time is unclear and, in both cases, appear significant for 60% of stations.

  6. Prevalence and determinants of metabolic syndrome among adults in a rural area of Northwest China.

    Directory of Open Access Journals (Sweden)

    Yaling Zhao

    Full Text Available To evaluate the prevalence and determinants of metabolic syndrome (MetS among adults in a rural area of Northwest China.A population-based cross-sectional study was conducted in 2010 among adults aged 18 to 80 years in rural areas of Hanzhong, in Northwest China. Interview, physical and clinical examinations, and fasting blood glucose and lipid measurements were completed for 2990 adults. The definitions of MetS proposed by the Third Report of the National Cholesterol Education Program Expert Panel (Adults Treatment Panel III, ATP III and the International Diabetes Federation (IDF, and the modified ATP III definition for Asian population were used and compared. Proportions were adjusted for age and sex.The prevalence of MetS was 7.9%, 10.8% and 15.1% according to ATP III, IDF and modified ATP III criteria, respectively. Agreement between ATP III and IDF criteria and that between ATP III and modified ATP III criteria were moderate (Kappa = 0.52 and 0.64, respectively, whereas agreement between IDF and modified ATP III criteria was good (Kappa = 0.83. The prevalence of MetS increased with age, and was higher in women than in men (10.4% versus 5.4%, 13.6% versus 8.1% and 17.4% versus 12.8%, according to ATP III, IDF and modified ATP III criteria, respectively. The most common MetS component was high blood pressure. Having family history of hypertension, lack of physical activity, high economical level, overweight and obesity were positively associated with MetS.MetS is prevalent among rural adults in Northwest China and high blood pressure is the most common MetS component. Prevention and treatment of hypertension and MetS should be a public health priority to reduce cardiovascular diseases in rural areas of Northwest China. More attention should be given to the elderly, women, people with family history of hypertension and obese people who are at high risk of MetS.

  7. Two new Gammarus species and a new name (Crustacea: Amphipoda: Gammaridae) from Northwest China.

    Science.gov (United States)

    Zhao, Shuangyan; Meng, Kaibaryer; Hou, Zhonge

    2017-06-02

    Two new species of the genus Gammarus are described and illustrated from Northwest China. A new species name Gammarus tianshan nom. nov. is proposed to replace G. montanus Hou et al., 2004. Gammarus simplex sp. nov. from Altay, Xinjiang, is characterized by uropod III with simple setae on both rami and urosomite I only with setae on dorsal margin. Gammarus glaber sp. nov. from Qinghai, is characterized by uropod III with few simple and plumose setae. Detailed morphological description and differences from related species are discussed. A distribution map of the new species and related species is provided.

  8. Prevalence and determinants of metabolic syndrome among adults in a rural area of Northwest China.

    Science.gov (United States)

    Zhao, Yaling; Yan, Hong; Yang, Ruihai; Li, Qiang; Dang, Shaonong; Wang, Yuying

    2014-01-01

    To evaluate the prevalence and determinants of metabolic syndrome (MetS) among adults in a rural area of Northwest China. A population-based cross-sectional study was conducted in 2010 among adults aged 18 to 80 years in rural areas of Hanzhong, in Northwest China. Interview, physical and clinical examinations, and fasting blood glucose and lipid measurements were completed for 2990 adults. The definitions of MetS proposed by the Third Report of the National Cholesterol Education Program Expert Panel (Adults Treatment Panel III, ATP III) and the International Diabetes Federation (IDF), and the modified ATP III definition for Asian population were used and compared. Proportions were adjusted for age and sex. The prevalence of MetS was 7.9%, 10.8% and 15.1% according to ATP III, IDF and modified ATP III criteria, respectively. Agreement between ATP III and IDF criteria and that between ATP III and modified ATP III criteria were moderate (Kappa = 0.52 and 0.64, respectively), whereas agreement between IDF and modified ATP III criteria was good (Kappa = 0.83). The prevalence of MetS increased with age, and was higher in women than in men (10.4% versus 5.4%, 13.6% versus 8.1% and 17.4% versus 12.8%, according to ATP III, IDF and modified ATP III criteria, respectively). The most common MetS component was high blood pressure. Having family history of hypertension, lack of physical activity, high economical level, overweight and obesity were positively associated with MetS. MetS is prevalent among rural adults in Northwest China and high blood pressure is the most common MetS component. Prevention and treatment of hypertension and MetS should be a public health priority to reduce cardiovascular diseases in rural areas of Northwest China. More attention should be given to the elderly, women, people with family history of hypertension and obese people who are at high risk of MetS.

  9. Multiple cooling episodes in the Central Tarim (Northwest China) revealed by apatite fission track analysis and vitrinite reflectance data

    Science.gov (United States)

    Chang, Jian; Qiu, Nansheng; Song, Xinying; Li, Huili

    2016-06-01

    Apatite fission track and vitrinite reflectance are integrated for the first time to study the cooling history in the Central Tarim, northwest China. The paleo-temperature profiles from vitrinite reflectance data of the Z1 and Z11 wells showed a linear relationship with depth, suggesting an approximately 24.8 °C/km paleo-geothermal gradient and 2700-3900 m of erosion during the Early Mesozoic. The measured apatite fission track ages from well Z2 in the Central Tarim range from 39 to 159 Ma and effectively record the Meso-Cenozoic cooling events that occurred in Central Tarim. Moreover, two cooling events at 190-140 Ma in the Early Jurassic-Early Cretaceous and 80-45 Ma in the Late Cretaceous-Paleocene revealed by measured AFT data and thermal modeling results are related to the collisions of the Qiangtang-Lhasa terranes and the Greater India Plate with the southern margin of the Eurasian Plate, respectively. This study provides new insights into the tectonic evolution of the Tarim Basin (and more broadly Central Asia) and for hydrocarbon generation and exploration in the Central Tarim.

  10. Late Quaternary stratigraphy, sedimentology, and geochemistry of an underfilled lake basin in the Puna (north-west Argentina)

    Science.gov (United States)

    McGlue, Michael M.; Cohen, Andrew S.; Ellis, Geoffrey S.; Kowler, Andrew L.

    2013-01-01

    Depositional models of ancient lakes in thin-skinned retroarc foreland basins rarely benefit from appropriate Quaternary analogues. To address this, we present new stratigraphic, sedimentological and geochemical analyses of four radiocarbon-dated sediment cores from the Pozuelos Basin (PB; northwest Argentina) that capture the evolution of this low-accommodation Puna basin over the past ca. 43 cal kyr. Strata from the PB are interpreted as accumulations of a highly variable, underfilled lake system represented by lake-plain/littoral, profundal, palustrine, saline lake and playa facies associations. The vertical stacking of facies is asymmetric, with transgressive and thin organic-rich highstand deposits underlying thicker, organic-poor regressive deposits. The major controls on depositional architecture and basin palaeogeography are tectonics and climate. Accommodation space was derived from piggyback basin-forming flexural subsidence and Miocene-Quaternary normal faulting associated with incorporation of the basin into the Andean hinterland. Sediment and water supply was modulated by variability in the South American summer monsoon, and perennial lake deposits correlate in time with several well-known late Pleistocene wet periods on the Altiplano/Puna plateau. Our results shed new light on lake expansion–contraction dynamics in the PB in particular and provide a deeper understanding of Puna basin lakes in general.

  11. Statistical Analysis of Acoustic Signal Propagating Through the South China Sea Basin

    Science.gov (United States)

    2016-03-01

    ANALYSIS OF ACOUSTIC SIGNAL PROPAGATING THROUGH THE SOUTH CHINA SEA BASIN by Meihuei Chen March 2016 Thesis Advisor...ACOUSTIC SIGNAL PROPAGATING THROUGH THE SOUTH CHINA SEA BASIN 5. FUNDING NUMBERS 6. AUTHOR(S) Meihuei Chen 7. PERFORMING ORGANIZATION NAME(S) AND...China Sea (SCS) basin to study the effects of nonlinear internal waves on 400- Hz acoustic signal propagation. The acoustic arrival structure for this

  12. Aeolian particle transport inferred using a ~150-year sediment record from Sayram Lake, arid northwest China

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    Long Ma

    2015-05-01

    Full Text Available We studied sediment cores from Sayram Lake in the Tianshan Mountains of northwest China to evaluate variations in aeolian transport processes over the past ~150 years. Using an end-member modeling algorithm of particle size data, we interpreted end members with a strong bimodal distribution as having been transported by aeolian processes, whereas other end members were interpreted to have been transported by fluvial processes. The aeolian fraction accounted for an average of 27% of the terrigenous components in the core. We used the ratio of aeolian to fluvial content in the Sayram Lake sediments as an index of past intensity of aeolian transport in the Tianshan Mountains. During the interval 1910-1930, the index was high, reflecting the fact that dry climate provided optimal conditions for aeolian dust transport. From 1930-1980, the intensity of aeolian transport was weak. From the 1980s to the 2000s, aeolian transport to Sayram Lake increased. Although climate in northwest China became more humid in the mid-1980s, human activity had by that time altered the impact of climate on the landscape, leading to enhanced surface erosion, which provided more transportable material for dust storms. Comparison of the Lake Sayram sediment record with sediment records from other lakes in the region indicates synchronous intervals of enhanced aeolian transport from 1910 to 1930 and 1980 to 2000.

  13. Planning for Regional Water Resources in Northwest China Using a Dynamic Simulation Model

    Science.gov (United States)

    Chen, C.; Kalra, A.; Ahmad, S.

    2014-12-01

    Problem of water scarcity is prominent in northwest China due to its typical desert climate. Exceedence of sustainable yield of groundwater resources has resulted in groundwater depletion, which has raised a series of issues such as drying wells, increasing pumping costs and environmental damage. With a rapid agricultural and economic development, population increase has added extra stress on available water resources by increasing municipal, agricultural and industrial demands. This necessitates efficient water resources management strategies with better understanding of the causes of water stress and options for sustainable development of economy and management of environment. This study focuses on simulating the water supply and demand, under the influence of changing climate, for Shanshan County, located in northwest of China. A dynamic simulation model is developed using the modeling tool Stella for monthly water balance for the period ranging from 2000-2030. Different future water demand and supply scenarios are developed to represent: (1) base scenario- with current practices; (2) change of the primary water source; (3) improvement of irrigation efficiency; (4) reduction of irrigation area; and (5) reduction of industrial water demand. The results indicate that besides growing demand, the low water use efficiency and low level of water reuse are the primary concerns for water scarcity. Groundwater recharge and abstraction could be balanced by 2030, by reducing industrial demand by 50% and using high efficiency irrigation for agriculture. The model provided a better understanding of the effect of different policies and can help in identifying water resources management strategies.

  14. [Markov process of vegetation cover change in arid area of northwest China based on FVC index].

    Science.gov (United States)

    Wang, Zhi; Chang, Shun-li; Shi, Qing-dong; Ma, Ke; Liang, Feng-chao

    2010-05-01

    Based on the fractional vegetation cover (FVC) data of 1982-2000 NOAA/AVHRR (National Oceanic and Atmospheric Administration/ the Advanced Very High Resolution Radiometer) images, the whole arid area of Northwest China was divided into three sub-areas, and then, the vegetation cover in each sub-area was classified by altitude. Furthermore, the Markov process of vegetation cover change was analyzed and tested through calculating the limit probability of any two years and the continuous and interval mean transition matrixes of vegetation cover change with 8 km x 8 km spatial resolution. By this method, the Markov process of vegetation cover change and its indicative significance were approached. The results showed that the vegetation cover change in the study area was controlled by some random processes and affected by long-term stable driving factors, and the transitional change of vegetation cover was a multiple Markov process. Therefore, only using two term image data, no matter they were successive or intervallic, Markov process could not accurately estimate the trend of vegetation cover change. As for the arid area of Northwest China, more than 10 years successive data could basically reflect all the factors affecting regional vegetation cover change, and using long term average transition matrix data could reliably simulate and predict the vegetation cover change. Vegetation cover change was a long term dynamic balance. Once the balance was broken down, it should be a long time process to establish a new balance.

  15. Land degradation mapping based on hyperion data in desertification region of northwest China

    Science.gov (United States)

    Cheng, Penggen; Wu, Jian; Ouyang, Ping; He, Ting

    2008-10-01

    Desertification is an alarming sign of land degradation in Henshan county of northwest china. Due to the considerable costs of detailed ground surveys of this phenomenon, remote sensing is an appropriate alternative for analyzing and evaluating the risks of the expansion of land degradation. Degradation features can be detected directly or indirectly by using image data. In this paper, based on the Hyperion images of Hengshan desertification region of northwest china, a new algorithm aimed at land degradation mapping, called Land Degradation Index (LDI), was put forward. This new algorithm is based on the classified process. We applied the linear spectral unmixing algorithm with the training samples derived from the formerly classified process so as to find out new endmembers in the RMS error imagine. After that, using neutral net mapping with new training samples, the classified result was gained. In addition, after applying mask processing, the soils were grouped to 3 types (Kappa =0.90): highly degraded soils, moderately degraded soils and slightly degraded soils. By analyzing 3 mapping methods: mixture-classification, the spectral angle mapper and mixturetuned matched filtering, the results suggest that the mixture-classification has the higher accuracy (Kappa=0.7075) than the spectral angle mapper (Kappa=0.5418) and the mixture-tuned matched filter (Kappa=0.6039). As a result, the mixture-classification is selected to carry out Land Degradation Index analysis.

  16. Ecosystem Evapotranspiration as a Response to Climate and Vegetation Coverage Changes in Northwest Yunnan, China.

    Science.gov (United States)

    Yang, Hao; Luo, Peng; Wang, Jun; Mou, Chengxiang; Mo, Li; Wang, Zhiyuan; Fu, Yao; Lin, Honghui; Yang, Yongping; Bhatta, Laxmi Dutt

    2015-01-01

    Climate and human-driven changes play an important role in regional droughts. Northwest Yunnan Province is a key region for biodiversity conservation in China, and it has experienced severe droughts since the beginning of this century; however, the extent of the contributions from climate and human-driven changes remains unclear. We calculated the ecosystem evapotranspiration (ET) and water yield (WY) of northwest Yunnan Province, China from 2001 to 2013 using meteorological and remote sensing observation data and a Surface Energy Balance System (SEBS) model. Multivariate regression analyses were used to differentiate the contribution of climate and vegetation coverage to ET. The results showed that the annual average vegetation coverage significantly increased over time with a mean of 0.69 in spite of the precipitation fluctuation. Afforestation/reforestation and other management efforts attributed to vegetation coverage increase in NW Yunnan. Both ET and WY considerably fluctuated with the climate factors, which ranged from 623.29 mm to 893.8 mm and -51.88 mm to 384.40 mm over the time period. Spatially, ET in the southeast of NW Yunnan (mainly in Lijiang) increased significantly, which was in line with the spatial trend of vegetation coverage. Multivariate linear regression analysis indicated that climatic factors accounted for 85.18% of the ET variation, while vegetation coverage explained 14.82%. On the other hand, precipitation accounted for 67.5% of the WY. We conclude that the continuous droughts in northwest Yunnan were primarily climatically driven; however, man-made land cover and vegetation changes also increased the vulnerability of local populations to drought. Because of the high proportion of the water yield consumed for subsistence and poor infrastructure for water management, local populations have been highly vulnerable to climate drought conditions. We suggest that conservation of native vegetation and development of water

  17. Ecosystem Evapotranspiration as a Response to Climate and Vegetation Coverage Changes in Northwest Yunnan, China.

    Directory of Open Access Journals (Sweden)

    Hao Yang

    Full Text Available Climate and human-driven changes play an important role in regional droughts. Northwest Yunnan Province is a key region for biodiversity conservation in China, and it has experienced severe droughts since the beginning of this century; however, the extent of the contributions from climate and human-driven changes remains unclear. We calculated the ecosystem evapotranspiration (ET and water yield (WY of northwest Yunnan Province, China from 2001 to 2013 using meteorological and remote sensing observation data and a Surface Energy Balance System (SEBS model. Multivariate regression analyses were used to differentiate the contribution of climate and vegetation coverage to ET. The results showed that the annual average vegetation coverage significantly increased over time with a mean of 0.69 in spite of the precipitation fluctuation. Afforestation/reforestation and other management efforts attributed to vegetation coverage increase in NW Yunnan. Both ET and WY considerably fluctuated with the climate factors, which ranged from 623.29 mm to 893.8 mm and -51.88 mm to 384.40 mm over the time period. Spatially, ET in the southeast of NW Yunnan (mainly in Lijiang increased significantly, which was in line with the spatial trend of vegetation coverage. Multivariate linear regression analysis indicated that climatic factors accounted for 85.18% of the ET variation, while vegetation coverage explained 14.82%. On the other hand, precipitation accounted for 67.5% of the WY. We conclude that the continuous droughts in northwest Yunnan were primarily climatically driven; however, man-made land cover and vegetation changes also increased the vulnerability of local populations to drought. Because of the high proportion of the water yield consumed for subsistence and poor infrastructure for water management, local populations have been highly vulnerable to climate drought conditions. We suggest that conservation of native vegetation and development of water

  18. Air pollution modeling over the Ganges basin and north-west Bay of Bengal in the early post-monsoon season using the NASA GEOS-5 model

    Science.gov (United States)

    Kishcha, Pavel; da Silva, Arlindo; Starobinets, Boris; Alpert, Pinhas

    2014-05-01

    The Ganges basin is characterized by a significant population growth accompanied by developing industry, agriculture, and increasing transportation. This has resulted in increased anthropogenic emissions and declining air quality. The NASA GEOS-5 model was used to extend the MERRA reanalysis with five atmospheric aerosol components (sulfates, organic carbon, black carbon, desert dust, and sea-salt). The model includes assimilation of bias-corrected Aerosol Optical Thickness (AOT) from the MODIS sensor on both Terra and Aqua satellites. The obtained eight-year (2002 - 2009) MERRA-driven aerosol dataset (MERRAero) was applied to study AOT and its trends over the Ganges basin and north-west Bay of Bengal (BoB) in the early post-monsoon season. This season is characterized by aerosol transport from the Ganges basin to north-west BoB by prevailing winds; lower cloud fraction compared to the monsoon season; and still significant rainfall of over 150 mm/month. In the early post-monsoon season (October), modeled data showed that AOT was lower over the east of the Ganges basin than over the north-west of the Ganges basin: this was despite the fact that the east of the Ganges basin should have produced higher anthropogenic aerosol emissions due to higher population density, increased industrial output and transportation. This is evidence that higher aerosol emissions do not always correspond to higher AOT over the areas where the effects of meteorological factors on AOT dominate those of aerosol emissions. MODIS AOT assimilation was essential for correcting modeled AOT mainly over the north-west of the Ganges basin, where AOT increments were maximal. Over the east of the Ganges basin and north-west BoB, AOT increments were low and MODIS AOT assimilation did not contribute significantly to modeled AOT. Our analysis showed that increasing AOT trends over north-west BoB (exceeding those over the east of the Ganges basin) were reproduced by GEOS-5, not because of MODIS AOT

  19. Electrical structures in the northwest margin of the Junggar basin: Implications for its late Paleozoic geodynamics

    Science.gov (United States)

    Zhang, Sheng; Xu, Yixian; Jiang, Li; Yang, Bo; Liu, Ying; Griffin, W. L.; Luo, Yong; Huang, Rong; Zhou, Yong; Zhang, Liangliang

    2017-10-01

    Recent geological, geochemical and geophysical data have inclined to support the presence of a remnant Paleozoic oceanic lithosphere beneath the Western Junggar, southwestern Chinese Altaids. However, regional high-resolution geophysical data have been rarely deployed to image its geometry, making it difficult to trace its evolution and final geodynamic setting. Presently, two magnetotelluric (MT) profiles are deployed across the northwest margin of the Junggar basin and the southern Darbut belt to image the electrical structure of the crust and lithospheric mantle. High-quality data at 102 sites and the quasi-2D indications of phase tensor skew angles and impedance phase ellipses for relatively short periods (up to 500 s) allow us to invert the two profile data by a 2-D scheme. The resistivity cross-section of a NW-SE striking LINE2 sheds light on a fossil intraoceanic subduction system, and reveals the Miaoergou intrusions as a bowl-like pluton, indicating that the multi-phase intrusions primarily formed in a post-collisional setting. The resistivity cross-section of striking NE-SW LINE1 reveals a possible oceanic slab with relatively lower resistivity underlying the low-resistivity sedimentary strata and high-resistivity mélange. Given that the profile of LINE1 cuts the out-rise zone of a subducted slab developed during the late Paleozoic, the 2-D resistivity model may thus represent the zone that have experienced heterogeneous deformation, reflecting subduction with barrier variation parallel to the ancient trench. Moreover, as shown in previous results, the new MT data also illustrate that the Darbut Fault is a thin-skinned structure, which has been erased at depths during the subsequent magmatism.

  20. Epidemiology of human fascioliasis and intestinal parasitosis among schoolchildren in Lake Tana Basin, northwest Ethiopia.

    Science.gov (United States)

    Fentie, Tsegaw; Erqou, Sebhat; Gedefaw, Molla; Desta, Almaw

    2013-08-01

    Parasitic diseases are the second most frequent cause of outpatient morbidity in Ethiopia. A cross-sectional study was conducted in Lake Tana Basin, northwest Ethiopia, from November 2007 to February 2008, to assess the magnitude and associated risk factors for parasitic diseases, including human fascioliasis. We examined 520 stool samples from randomly selected schoolchildren in six schools by microscopy. Rapid sedimentation and Kato-Katz techniques were used to detect and count Fasciola and Schistosoma eggs. The formol-ether concentration method was used for the identification of other helminth eggs, larvae and cysts of protozoan parasites. The overall prevalence of intestinal parasitic infections was 71.3% (95% CI 67.3-75.1%). Hookworm was the predominant intestinal parasite (23.5%, 95% CI 19.8-27.1%), followed by Ascaris lumbricoides (18.5%, 95% CI 15.2-21.9%) and Schistosoma mansoni (16.7%, 95% CI 13.5-19.9%). One hundred and sixty-three (31.4%) children had multiple parasitic infections. The most relevant finding was a prevalence of Fasciola spp. of 3.3% in an area where only sporadic cases have been reported previously. The risk of Fasciola spp. infection was significantly associated with raw vegetable consumption, use of unsafe drinking water sources, irrigation practices and sheep and/or cattle ownership. Irrigation practices, male gender, raw vegetable consumption and use of unsafe drinking water sources were risk factors for S. mansoni infection. A high prevalence of parasitic infections among children in the region was found, including a relatively high prevalence of Fasciola spp. infection. Epidemiological studies on the magnitude of parasitic infections in different regions will enable high-risk communities to be identified and allow for planning of appropriate interventions.

  1. Soya and isoflavone intakes associated with reduced risk of oesophageal cancer in north-west China.

    Science.gov (United States)

    Tang, Li; Lee, Andy H; Xu, Fenglian; Zhang, Taotao; Lei, Jun; Binns, Colin W

    2015-01-01

    To ascertain the association between soya consumption, isoflavone intakes and oesophageal cancer risk in remote north-west China, where the incidence of oesophageal cancer is known to be high. Case-control study. Information on habitual consumption of soya foods and soya milk was obtained by personal interview. The intakes of isoflavones were then estimated using the US Department of Agriculture nutrient database. Logistic regression analyses were performed to assess the association between soya consumption, isoflavone intakes and oesophageal cancer risk. Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region, China. Participants were 359 incident oesophageal cancer patients and 380 hospital-based controls. The oesophageal cancer patients consumed significantly less (P soya foods (mean 57·2 (sd 119·0) g/d) and soya milk (mean 18·8 (sd 51·7) ml/d) than the controls (mean 93·3 (sd 121·5) g/d and mean 35·7 (sd 73·0) ml/d). Logistic regression analyses showed an inverse association between intake of soya products and the risk of oesophageal cancer. The adjusted odds were OR = 0·33 (95 % CI 0·22, 0·49) and OR = 0·48 (95 % CI 0·31, 0·74) for consuming at least 97 g of soya foods and 60 ml of soya milk daily (the highest tertiles of consumption), respectively, relative to the lowest tertiles of consumption. Similarly, inverse associations with apparent dose-response relationships were found between isoflavone intakes and oesophageal cancer risk. Habitual consumption of soya products appears to be associated with reduced risk of oesophageal cancer in north-west China.

  2. White rice consumption and risk of esophageal cancer in Xinjiang Uyghur Autonomous Region, northwest China: a case-control study

    OpenAIRE

    Tang, Li; Xu, Fenglian; Zhang, Taotao; Lei, Jun; Binns, Colin W.; Lee, Andy H.

    2015-01-01

    This study investigated the association between white rice consumption and the risk of esophageal cancer in remote northwest China, where the cancer incidence is known to be high. A case-control study was conducted during 2008?2009 in Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region of China. Participants were 359 incident esophageal cancer patients and 380 hospital-based controls. Information on habitual white rice consumption was obtained by personal interview using a validated semi-qu...

  3. Survival and associated mortality risk factors among post-treatment pulmonary tuberculosis patients in the northwest of China

    NARCIS (Netherlands)

    Wang, X.H.; Ma, A.G.; Han, X.X.; Liang, H.; Wang, D.; Schouten, E.; Kok, F.

    2015-01-01

    OBJECTIVE: The tuberculosis (TB) program was carried out in the Changji zone in northwest of China. Directly Observed Treatment, Short-Course (DOTS) is a modern control strategy against tuberculosis recommended by World Health Organization. The purpose of this work is to describe the survival of

  4. A population-based study examining hepatitis B virus infection and immunization rates in Northwest China.

    Directory of Open Access Journals (Sweden)

    Zhaohua Ji

    Full Text Available BACKGROUND AND AIM: Current baseline data regarding the prevalence of hepatitis B virus (HBV infections and the immune status in hyperendemic areas is necessary in evaluating the effectiveness of ongoing HBV prevention and control programs in northwest China. This study aims to determine the prevalence of chronic HBV infections, past exposure rates, and immune response profiles in Wuwei City, northwest China in 2010. METHODS: Cross-sectional household survey representative of the Wuwei City population. 28,579 participants were interviewed in the seroepidemiological survey ≥1 year of age. House to house screening was conducted using a standard questionnaire. All serum samples were screened by enzyme-linked immunoassays for the presence of hepatitis B surface antigen, antibodies against HBV surface antigen, and antibodies to the hepatitis B core antigen. RESULTS: Among individuals ≥1 year of age, 7.2% (95%CI: 6.3-8.1% had chronic HBV infections, 43.9% (CI: 40.4-47.4% had been exposed to HBV, and 23.49% (CI: 21.6-25.3% had vaccine-induced immunity. Multi-factor weighted logistic regression analysis showed that having household contact with HBV carriers (OR = 2.6, 95%CI: 2.3-3.0 and beauty treatments in public places (OR = 1.2, 95%CI: 1.1-1.3 were the risk factors of HBV infection in whole population. Having household contact with HBV carriers (OR = 3.8, 95% CI: 2.2-6.5 and lack of hepatitis vaccination (OR = 2.0, 95% CI: 1.4-3.3 were the risk factors for HBV infection in children aged 1-14 years. CONCLUSIONS: Hepatitis B infection remains a serious public health problem in northwest China. Having household contact with HBV carriers and beauty treatments in public places represented HBV infection risk factors. Hepatitis B vaccine immunization strategies need further improvement, particularly by targeting the immunization of rural migrant workers.

  5. Quantitative Analysis and Comparison of BMI among Han, Tibetan, and Uygur University Students in Northwest China

    Directory of Open Access Journals (Sweden)

    Bai Jingya

    2013-01-01

    Full Text Available Objectives. To fully analyze and compare BMI among Han, Tibetan, and Uygur university students, to discuss the differences in their physical properties and physical health, and thus to provide some theoretical suggestions for the improvement of students’ physical health. Methods. The cross-sectional random cluster sampling was used to investigate 10103 Han, Tibetan, and Uygur university students, aged 20–24 in Northwest China, and their height and weight were measured to calculate BMI. The BMI classification criteria for Chinese established by Work Group on Obesity in China (WGOC were used for screening. Results. Han, Tibetan, and Uygur university students show low obesity rates but high overweight rates. Han, Tibetan, and Uygur university students present a high rate of underweight, normal weight, and overweight, respectively. Female Han students show higher underweight and normal weight rates, but lower overweight and obesity rates, than male Han students. Female Tibetan students show higher normal weight rate, but lower overweight and obesity rates, than male Tibetan students. BMI increases with age for male students but decreases with age for female students. Male Uygur students show higher obesity rate than female Uygur students. Tibetan and Uygur university students have higher BMI than other minorities in South China.

  6. Quantitative Analysis and Comparison of BMI among Han, Tibetan, and Uygur University Students in Northwest China

    Science.gov (United States)

    Jingya, Bai; Ye, He; Jing, Wang; Xi, Huanjiu; Tao, Hai

    2013-01-01

    Objectives. To fully analyze and compare BMI among Han, Tibetan, and Uygur university students, to discuss the differences in their physical properties and physical health, and thus to provide some theoretical suggestions for the improvement of students' physical health. Methods. The cross-sectional random cluster sampling was used to investigate 10103 Han, Tibetan, and Uygur university students, aged 20–24 in Northwest China, and their height and weight were measured to calculate BMI. The BMI classification criteria for Chinese established by Work Group on Obesity in China (WGOC) were used for screening. Results. Han, Tibetan, and Uygur university students show low obesity rates but high overweight rates. Han, Tibetan, and Uygur university students present a high rate of underweight, normal weight, and overweight, respectively. Female Han students show higher underweight and normal weight rates, but lower overweight and obesity rates, than male Han students. Female Tibetan students show higher normal weight rate, but lower overweight and obesity rates, than male Tibetan students. BMI increases with age for male students but decreases with age for female students. Male Uygur students show higher obesity rate than female Uygur students. Tibetan and Uygur university students have higher BMI than other minorities in South China. PMID:24453807

  7. NPP estimation and seasonal change research of Gansu province in northwest China

    Science.gov (United States)

    Han, Tao; Wang, Dawei; Hao, Xiaocui; Jiang, Youyan

    2018-03-01

    Based on GIS and remote sensing technology, this paper estimates the NPP of the 2015 year-round and every season of Gansu province in northwest China by using the CASA(Carnegie Ames Stanford Approach) light energy utilization model. The result shows that the total annual NPP of Gansu province gradually decline from southeast to northwest in the space, which is in accordance with the water and heat condition in Gansu province. The results show that the summer NPP in Gansu Province is the maximum in each season. The maximum value of summer NPP in Gansu Province reached 695 (gCm-2•season-1), and the maximum value was 473 in spring, and 288 in the autumn, and the NPP in the winter in Gansu province were under 60. The fluctuation range of NPP value is large, this is due to the diversity of ecosystem types in Gansu province, including desert, grassland, farmland and forest, among them, the grassland area is the largest, and the grassland type is very diverse, the grassland coverage is obviously different, especially the low coverage grassland growth is affected by precipitation and temperature and other meteorological factors obviously.

  8. Effects of irrigation and nitrogen management on hybrid maize seed production in north-west China

    Directory of Open Access Journals (Sweden)

    Hui RAN,Shaozhong KANG,Fusheng LI,Ling TONG,Taisheng DU

    2016-03-01

    Full Text Available Scientific irrigation and nitrogen management is important for agricultural production in arid areas. To quantify the effect of water and nitrogen management on yield components, biomass partitioning and harvest index (HI of maize for seed production with plastic film-mulching, field experiments including different irrigation and N treatments were conducted in arid north-west China in 2013 and 2014. The results indicated that kernel number per plant (KN was significantly affected by irrigation and N treatments. However, 100-kernel weight was relatively stable. Reducing irrigation quantity significantly increased stem partitioning index (PIstem and leaf partitioning index (PIleaf, and decreased ear partitioning index (PIear at harvest, but lowering N rate (from 500 to 100 kg N·hm-2 did not significantly reduce PIstem, PIleaf, and PIear at harvest. HI was significantly reduced by reducing irrigation quantity, but not by reducing N rate. Linear relationships were found between KN, PIstem, PIleaf, PIear at harvest and HI and evapotranspiration (ET.

  9. Empirical study on regional differentiation of rural household energy use in Northwest China

    Science.gov (United States)

    Wu, Wenheng; Zhang, Xin; Guo, Xiaodong

    2018-02-01

    To better understand regional differentiation of rural household energy use, data of energy use of 232 rural households in the Linwei District located in the lower reaches of the Weihe River of Northwest China were collected by questionnaires combined with face-to-face interview. Location quotient of energy use (LQEU) method is adopted in the paper. The results show that multiple energy sources are utilized due to market orientation in the plain area, and biogas is prominent as a result of policy orientation in the loess tableland, whereas firewood is dominant due to the influence of natural environment in the Qinling mountainous area. Regional differentiation of energy use is comprehensively affected by income level, air temperature, development conditions, energy policy, etc.

  10. Establishment and assessment of cataract surgery in Day-care Unit at northwest of China

    Directory of Open Access Journals (Sweden)

    Xiu-Li Zhang

    2018-04-01

    Full Text Available AIM: To describe the protocol and economic cost of the Day-care Unit cataract surgery procedure in northwest of China.METHODS: Patients who received phacoemulcification and intraocular lens implantation in both Day-care Unit and regular Unit were recruited from January 2016 to December 2016. The baseline data and average cost were recorded and analyzed. Furthermore, satisfaction questionnaire of patients were collected.RESULTS: Patients with Day-care Unit showed shorter registration duration, less cost including housing and nursing charge as well as higher rate of patient satisfaction. Meanwhile, Day-care Unit shorten the time the doctors and nurses spending on filling the medical charts.CONCLUSION:Day-care Unit cataract surgery procedure could benefit both patients and medical staffs and is worthy to generalize.

  11. Estimation of net primary productivity using a process-based model in Gansu Province, Northwest China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peijuan; Xie, Donghui; Zhou, Yuyu; E, Youhao; Zhu, Qijiang

    2014-01-16

    The ecological structure in the arid and semi-arid region of Northwest China with forest, grassland, agriculture, Gobi, and desert, is complex, vulnerable, and unstable. It is a challenging and sustaining job to keep the ecological structure and improve its ecological function. Net primary productivity (NPP) modeling can help to improve the understanding of the ecosystem, and therefore, improve ecological efficiency. The boreal ecosystem productivity simulator (BEPS) model provides the possibility of NPP modeling in terrestrial ecosystem, but it has some limitations for application in arid and semi-arid regions. In this paper we improve the BEPS model, in terms of its water cycle by adding the processes of infiltration and surface runoff, to be applicable in arid and semi-arid regions. We model the NPP of forest, grass, and crop in Gansu Province as an experimental area in Northwest China in 2003 using the improved BEPS model, parameterized with moderate resolution remote sensing imageries and meteorological data. The modeled NPP using improved BEPS agrees better with the ground measurements in Qilian Mountain than that with original BEPS, with a higher R2 of 0.746 and lower root mean square error (RMSE) of 46.53 gC/m2 compared to R2 of 0.662 and RMSE of 60.19 gC/m2 from original BEPS. The modeled NPP of three vegetation types using improved BEPS show evident differences compared to that using original BEPS, with the highest difference ratio of 9.21% in forest and the lowest value of 4.29% in crop. The difference ratios between different vegetation types lie on the dependence on natural water sources. The modeled NPP in five geographic zones using improved BEPS are higher than those with original BEPS, with higher difference ratio in dry zones and lower value in wet zones.

  12. Optical properties and source analysis of aerosols over a desert area in Dunhuang, Northwest china

    Science.gov (United States)

    Ma, Yongjing; Xin, Jinyuan; Ma, Yining; Kong, Lingbin; Zhang, Kequan; Zhang, Wenyu; Wang, Yuesi; Wang, Xiuqin; Zhu, Yongfeng

    2017-08-01

    Aerosol observational data for 2012 obtained from Dunhuang Station of CARE-China (Campaign on Atmospheric Aerosol Research Network of China) were analyzed to achieve in-depth knowledge of aerosol optical properties over Dunhuang region. The results showed that the annual average aerosol optical depth (AOD) at 500 nm was 0.32±0.06, and the Ångström exponent ( α) was 0.73 ± 0.27. Aerosol optical properties revealed significant seasonal characteristics. Frequent sandstorms in MAM (March-April-May) resulted in the seasonal maximum AOD, 0.41 ± 0.04, and a relatively smaller α value, 0.44±0.04. The tourism seasons, JJA (June-July-August) and SON (September-October-November) coincide with serious emissions of small anthropogenic aerosols. While in DJF (December-January-February), the composition of the atmosphere was a mixture of dust particles and polluted aerosols released by domestic heating; the average AOD and α were 0.29 ± 0.02 and 0.66 ± 0.17, respectively. Different air masses exhibited different degrees of influence on the aerosol concentration over Dunhuang in different seasons. During MAM, ranges of AOD (0.11-1.18) and α (0.06-0.82) were the largest under the dust influence of northwest-short-distance air mass in the four trajectories. Urban aerosols transported by northwest-short-distance air mass accounted for a very large proportion in JJA and the mixed aerosols observed in SON were mainly conveyed by air masses from the west. In DJF, the similar ranges of AOD and α under the three air mass demonstrated the analogous diffusion effects on regional pollutants over Dunhuang.

  13. Distribution and diversity of rhizobia associated with wild soybean (Glycine soja Sieb. & Zucc.) in Northwest China.

    Science.gov (United States)

    Zhao, Liang; Fan, Miaochun; Zhang, Dehui; Yang, Ruiping; Zhang, Feilong; Xu, Lin; Wei, Xiuli; Shen, Yaoyao; Wei, Gehong

    2014-09-01

    A total of 155 nodule isolates that originated from seven sites in Northwest China were characterized by PCR-RFLP of the 16S rRNA gene and sequence analysis of multiple core genes (16S rRNA, recA, atpD, and glnII) in order to investigate the diversity and biogeography of Glycine soja-nodulating rhizobia. Among the isolates, 80 were Ensifer fredii, 19 were Ensifer morelense, 49 were Rhizobium radiobacter, and 7 were putative novel Rhizobium species. The phylogenies of E. fredii and E. morelense isolates in a concatenate tree (assembly of all housekeeping genes) were generally consistent with those in individual gene trees. However, incongruence was found in the phylogenies of the different genes of Rhizobium isolates, indicating that lateral transfer or recombination possibly occurred in these gene loci. Despite their species identity, all the isolates in this study formed a single lineage related to E. fredii in nodAand nifH gene phylogenies, which also indicated that the symbiotic genes were laterally transferred between different species. Biogeographic patterns were found at the species and strain genomic type levels, as revealed by BOXA1R fingerprinting, demonstrating that the evolution of rhizobial populations in different geographic locations was related to soil types, altitude and spatial effects. This study is the first to report that E. morelense, R. radiobacter, and Rhizobium sp. are microsymbionts of G. soja, as well as showing that the diversity of G. soja rhizobia is enhanced and new rhizobia have evolved in Northwest China. Copyright © 2014 Elsevier GmbH. All rights reserved.

  14. Effects of smoking and alcohol consumption on lipid profile in male adults in northwest rural China.

    Science.gov (United States)

    Li, X X; Zhao, Y; Huang, L X; Xu, H X; Liu, X Y; Yang, J J; Zhang, P J; Zhang, Y H

    2018-04-01

    To determine the individual and combined influences of smoking and alcohol consumption on lipid profile in male adults in northwest rural China. Cross-sectional study. In total, 4614 subjects were enrolled in the cross-sectional study, performed between 2008 and 2012. The present study examined males aged ≥18 years from northwest rural China (n = 707). Data on current smoking and drinking status were collected. Logistic regression was used to estimate the individual and combined influences of smoking and alcohol consumption on lipid profile. Age, ethnic group, educational background, smoking (or alcohol consumption), waist circumference, body mass index, blood pressure and fasting blood glucose were adjusted as confounders. Total cholesterol (TC)/high-density lipoprotein cholesterol (HDL-C) ratio, triglycerides (TG)/HDL-C ratio, low-density lipoprotein cholesterol (LDL-C)/HDL-C ratio and visceral adiposity index (VAI) were significantly higher in smokers than in non-smokers, whereas HDL-C was lower in smokers. TG/HDL-C ratio, LDL-C/HDL-C ratio, TG, lipid accumulation product and VAI were significantly higher in drinkers than non-drinkers. After adjustment for confounders, significant relationships were observed between smoking status and any dyslipidemia, low HDL-C and high VAI (odds ratios [ORs]: 2.53 [95% confidence interval {CI}: 1.25-5.15], 6.13 [95% CI: 2.84-13.25] and 4.39 [95% CI: 2.02-9.54], respectively). The OR for any dyslipidaemia was 1.94 (95% CI: 1.09-3.48) for subjects who smoke and drank alcohol compared with subjects who did not smoke or drink alcohol. Abnormalities in lipid profile are correlated with smoking and alcohol consumption, which calls for intervention strategies to prevent dyslipidaemia and control risk factors for cardiovascular disease. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  15. Current attitudes toward organ donation after cardiac death in northwest China.

    Science.gov (United States)

    Pan, Xiaoming; Liu, Linjuan; Xiang, Heli; Ding, Chenguang; Ren, Li; Xue, Wujun

    2014-01-01

    People's attitude toward organ donation after cardiac death (DCD) has not come to an agreement in different countries and regions. Influenced by the local culture in China for thousands of years, the general public has different ideas about this issue. The purpose of this study was to investigate the current attitudes trend and characteristics of transplantation with organs donated after cardiac death in northwest China. This largest single-center cohort study was performed by an interview or by telephone using a questionnaire. The family members of potential DCD donors were recruited from the First Affiliated Hospital, medical college of Xi'an Jiaotong University located in a metropolitan area of northwest China. The 12-item attitude questionnaire was specifically developed from the literature review with coordinator, physician, and donor's family feedback. The participants were asked to rate the queries on a 5-point Likert intensity scale. The 174 participants included 56 (32.2%) women and 118 (67.8%) men. Most people were aged between 41 and 50 years (n = 63, 36.2%), 31 and 40 years (n = 59, 33.9%), and less than 30 years (n = 36, 20.7%). The top five attitudes of participants were the best person to suggest organ donation to a family was ranked as the DCD coordinator of Red Cross Organization (RCO, n = 160, 92%), donor is a hero (n = 143, 82.2%), honor to be a donor's family member (n = 136, 78.2%), improved relationship with colleagues (n = 124, 71.3%), and with recipient after donation (n = 123, 70.7%). The best person to suggest organ donation to a family was ranked as the coordinator of RCO (n = 160, 92%), doctor unrelated to transplantation (n = 104, 59.8%), social worker (n = 36, 20.7%), and doctor related to transplantation (n = 25, 14.4%). The top two reasons for non-consent to donation were that the family insisted on intact body after patient death and did not want to have surgery again (n = 51, 41.5%), and feared that they would be misunderstood by

  16. Long-term dynamic characterization of aeolian desertification in northwest Shanxi, China.

    Science.gov (United States)

    Xue, Zhanjin; Qin, Zuodong; Cheng, Fangqin; Ding, Guangwei; Li, Hongjian

    2017-07-01

    Northwest Shanxi is located on the farming-pastoral ecotone of northern China, where aeolian desertification is one of the most serious environmental and socioeconomic issues. The remote sensing image and geostatistical approach were implemented to estimate aeolian desertified land (ADL) dynamic variations from 1975 to 2015. Results showed that the ADL covered 11,685.21 km 2 (82.29%) of the study area in 2015, the majority of which was classified as a light or moderate degree. The area of ADL gradually expanded at an increasing rate of 87.37 km 2 a -1 during the 1975-2000 periods. More specifically, the area of ADL has increased by 1259.23 km 2 from 1975 to 1990 and by 924.96 km 2 from 1990 to 2000, respectively. In contrast, spatial transfer of ADL areas has dwindled by 2365.85 km 2 with a net decrease of 157.72 km 2 a -1 , and the mitigated areas of aeolian desertification were 10,602.24 km 2 between 2000 and 2015. During the past 40 years, the gravity center of ADL migrated to southeast until 2000 and moved northwest in 2000-2015. From 1975 to 2000, the migration distance of severe ADL was the largest, migrated toward the northwest by 19.03 km in 1975-1990 and by 20.16 km in 1990-2000, respectively. From 2000 to 2015, the migration distance of light ADL was the largest, 27.54 km migrated to the northwest. Aeolian desertification rapidly expanded from 1975 to 2000 under the combination of climate change and intensive human activities. Since the year of 2000, ecological engineering strategy initiated by the governments has been the dominant contributor to the aeolian desertification severity reversal. Aeolian desertification prevention is a complicated process. Both the central and local government should play a critical role in the rehabilitation of ADL in the long term.

  17. Badlands in humid regions - redbed desertification in Nanxiong Basin, China

    Science.gov (United States)

    Yan, Luobin; Hua, Peng; Simonson, Scott

    2016-04-01

    The redbed badlands in Nanxiong City, China, well represent badlands in humid regions. The erosion rate in humid regions is much higher than that in arid regions and can reach 1 cm per month during the summer. The purpose of this study is to introduce the research of badlands in China, which have not been extensively studied so far, and to compare the badlands between arid and humid regions. Furthermore, the aim is to study the impact of mineralogical and chemical composition on the disintegration of soft rock in Nanxiong Basin badlands. For the purpose of this study field observations, sampling, and digging profiles were done. The mineralogical and chemical compositions of the Nanxiong Basin badland lithologies were determined by XRD, XRF and thin sections. Weathering resistance, process of weathering, and disintegration features were studied by weathering experiments under natural conditions. Weathering profiles can be easily divided into four layers: regolith, a strongly weathered layer, a poorly weathered layer, and an unweathered sediment. The depth of the weathering profile is influenced by the weathering resistance of the soft rock. Weathering resistance affects the erosion rate and evolution of landforms in badlands by influencing the rate from unweathered rock to regolith. Analyzed sediments have high content of illite and illite-smectite interstratifications. This composition of clay minerals together with poor sediment consolidation jointly leads to weathering prone sediment. The weathering and disintegration of soft rock in Nanxiong Basin badlands has a close relationship with rainfall. Sheet erosion, a kind of solid-liquid phase flow, formed in the regolith of the badland during rainfall events and can be the most instrumental to erosion. The mineral composition and liquidity plasticity index were also analyzed, and the results show that the regolith are low liquid limit silts with liquid limit of 21%-25%, plastic limit of 13%-18% and plasticity index

  18. Public perception of an ecological rehabilitation project in inland river basins in northern China: Success or failure.

    Science.gov (United States)

    Feng, Qi; Miao, Zheng; Li, Zongxing; Li, Jianguo; Si, Jianhua; S, Yonghong; Chang, Zongqiang

    2015-05-01

    The need for environmental protection challenges societies to deal with difficult problems because strategies designed by scientists to protect the environment often create negative effects on impoverished local residents. We investigated the effects of China's national and regional policies related to environmental protection and rehabilitation projects in inland river basins, by studying the effect of projects in the Heihe and Shiyang river basins, in northwest China. Interviews and surveys were conducted at 30 sites in the lower reaches of these two arid basins, an area that has experienced severe ecological degradation. The survey results show the ecological rehabilitation projects adversely affected the livelihoods of 70.35% of foresters, 64.89% of farmers and 62.24% of herders in the Minqing region in the lower Shiyang River Basin; also, the projects negatively affected 51.9% of residents in the Ejin Qi in the lower Heihe River Basin. This caused 16.33% of foresters, 39.90% of farmers and 45.32% of herders in the Minqing region to not support the project and 37.5% of residents in the Ejin Qi region said they will deforest and graze again after the project ends. The negative impacts of the policies connected to the projects cause these attitudes. The projects prohibit felling and grazing and require residents to give up groundwater mining; this results in a great amount of uncompensated economic loss to them. Extensive survey data document the concerns of local residents, concerns that are supported by the calculation of actual incomes. In addition, the surveys results show poorer interviewees believe the projects greatly affected their livelihoods. While citizens in this region support environment protection work, the poor require considerable assistance if one expects them to support this type of work. Governmental assistance can greatly improve their living conditions, and hence encourage them to participate in and support the implementation of the projects

  19. Geochemical characteristics of fossil Solenites murrayana cuticles from the Jurassic in Lanzhou, northwest China

    Energy Technology Data Exchange (ETDEWEB)

    Sun, B.N.; Yan, D.F.; Xie, S.P.; Shi, Y.J.; Zhang, C.J.; Lin, Z.C. [Lanzhou University, Lanzhou (China)

    2006-07-01

    Through geochemical analysis on cuticles of the Jurassic fossil Solenites murrayuna L. et H. from the Yaojie Coalfield in Lanzhou, northwest China, and by comparison of geochemical features with its nearest living equivalent, Ginkgo biloba, we show that the characteristics of organic matter of the fossil plant cuticles accord with evolutionary features of asphalt in oil formation. The content analysis of organic matter indicates that the geochemistry is equivalent to rotten mud-sapropel humus types from Mesozoic and Cenozoic source rock in China. Some analysis data of organic matter indicate that Solenites murrayana cuticles are in a low mature stage, which coincides with the hydrocarbon generation model of cutinite in coal. Moreover, distribution features of soluble organic matter of cuticles show that fossil plant cuticles have a definite action in forming terrestrial high-wax oil, which has testified the contribution of high plants to waxness. The present study proves that Ginkgophytes abundant in the Jurassic were a high potential plant in the formation of coal-bed hydrocarbon.

  20. Analysis of economic burden for patients with cystic echinococcosis in five hospitals in northwest China.

    Science.gov (United States)

    Wang, Le; Wen, Hao; Feng, Xiaohui; Jiang, Xiaoming; Duan, Xinyu

    2012-12-01

    The direct and indirect economic burden of human cystic echinococcosis (CE) was investigated in the five specialist hydatid hospitals in Xinjiang, PR China, to provide information for health policy in the future. A total of 2018 CE patients (age range 2-88 years) attending the hospitals were studied between 2004 and 2008. The per-person direct medical cost was US$1493.12 (95% CI 1438.43-1547.80) and the per-person direct non-medical cost was US$19.67. The indirect economic cost was US$1435.96 per person, and the disability-adjusted life-years (DALY) lost was approximately 1.03 DALY/person. This study is the first to combine the human capital method with DALYs to analyse the indirect CE economic burden in northwest China. Factors such as age, occupation and hospital level should be considered when developing polices to reduce the economic burden of CE. Copyright © 2012 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  1. Energy investment and trade opportunities emerging in Central Asia, Northwest China

    International Nuclear Information System (INIS)

    Dorian, J.P.; Abbasovich, T.U.; Tonkopy, M.S.; Jumabekovich, O.A.; Qiu Daxiong

    1998-01-01

    Cooperation in the business of oil and natural gas among governments of Central Asia and Northwest China could help the countries overcome obstacles to development of their vast petroleum resources. The most important obstacle facing these countries is also the one most widely discussed: limited infrastructure for transporting energy. But there are other problems holding back oil and gas development. They include poor communications infrastructure, unstable government structures, political conflict, payments difficulties, and inadequate energy policies. For countries analyzed in a recent Asian Development Bank (ADB) study of economic cooperation in the region--Uzbekistan, Kazakhstan, the Kyrgyz Republic, and the Xinjiang autonomous region of the People's Republic of China (Xinjiang PRC)--oil and gas are the most abundant and valuable natural resources. While Central Asia is poised to become a major world supplier of energy, especially oil and gas, countries in the region emphasize energy self-sufficiency at the expense of developing new trading linkages. Governments thus tend to ignore the benefits of regional cooperation and remain reluctant to commit to area-wide trade and other forms of cooperation. The paper discusses oil and gas sectors; major energy trends, including restructuring, foreign investment, and energy diversification; opportunities for cooperation; impediments to cooperation; and models of cooperation

  2. Ethnicity and anticoagulation management of hospitalized patients with atrial fibrillation in northwest China.

    Science.gov (United States)

    Cheng, Xinchun; Zhou, Xianhui; Song, Shifei; Wu, Min; Baolatejiang, Roza; Lu, Yanmei; Li, Yaodong; Zhang, Wenhui; Lv, Wenkui; Ye, Yuanzheng; Zhou, Qina; Wang, Hongli; Zhang, Jianghua; Xing, Qiang; Tang, Baopeng

    2017-04-10

    The therapeutic management and health challenges caused by atrial fibrillation (AF) differ between different groups. The purpose of this study was to investigate the clinical features of patients hospitalized with AF and to explore the use of anticoagulation treatments in Han and Uygur patients in Xinjiang, northwest China. Data were collected from a retrospective descriptive study involving patients hospitalized at 13 hospitals in Xinjiang, China from Jul 1, 2014 to Jun 31, 2015. Anticoagulation management was measured according to guideline-recommended risk scores. A total of 4,181 patients with AF were included (mean age 69.5 ± 11.7 years, 41.4% females; 71.5% Han, 28.5% Uygur). The prevalence of AF in Uygur individuals may occur earlier than in Han individuals (mean age 64.9 vs 71.3, P < 0.001). Most of the hospitalized patients with AF had a high risk of stroke (CHA 2 DS 2 -VASc score ≥2; 80.6% Han vs 73.7% Uygur, P < 0.05); this risk was especially high in elderly patients. In AF patients, the application of anticoagulants according to the guidelines is far from expected, and the underutilization of anticoagulants exists in both ethnic groups.

  3. Chemical composition, sources and secondary processes of aerosols in Baoji city of northwest China

    Science.gov (United States)

    Wang, Y. C.; Huang, R.-J.; Ni, H. Y.; Chen, Y.; Wang, Q. Y.; Li, G. H.; Tie, X. X.; Shen, Z. X.; Huang, Y.; Liu, S. X.; Dong, W. M.; Xue, P.; Fröhlich, R.; Canonaco, F.; Elser, M.; Daellenbach, K. R.; Bozzetti, C.; El Haddad, I.; Prévôt, A. S. H.; Canagaratna, M. R.; Worsnop, D. R.; Cao, J. J.

    2017-06-01

    Particulate air pollution is a severe environmental problem in China, affecting visibility, air quality, climate and human health. However, previous studies focus mainly on large cities such as Beijing, Shanghai, and Guangzhou. In this study, an Aerodyne Aerosol Chemical Speciation Monitor was deployed in Baoji, a middle size inland city in northwest China from 26 February to 27 March 2014. The non-refractory submicron aerosol (NR-PM1) was dominated by organics (55%), followed by sulfate (16%), nitrate (15%), ammonium (11%) and chloride (3%). A source apportionment of the organic aerosol (OA) was performed with the Sofi (Source Finder) interface of ME-2 (Multilinear Engine), and six main sources/factors were identified and classified as hydrocarbon-like OA (HOA), cooking OA (COA), biomass burning OA (BBOA), coal combustion OA (CCOA), less oxidized oxygenated OA (LO-OOA) and more oxidized oxygenated OA (MO-OOA), which contributed 20%, 14%, 13%, 9%, 23% and 21% of total OA, respectively. The contribution of secondary components shows increasing trends from clean days to polluted days, indicating the importance of secondary aerosol formation processes in driving particulate air pollution. The formation of LO-OOA and MO-OOA is mainly driven by photochemical reactions, but significantly influenced by aqueous-phase chemistry during periods of low atmospheric oxidative capacity.

  4. An integrated workflow to assess the remaining potential of mature hydrocarbon basins: a case study from Northwest Germany (Upper Jurassic/Lower Cretaceous, Lower Saxony Basin)

    Science.gov (United States)

    Seyfang, Björn; Aigner, Thomas; Munsterman, Dirk K.; Irmen, Anton

    2017-04-01

    Mature hydrocarbon provinces require a high level of geological understanding in order to extend the lives of producing fields, to replace reserves through smaller targets and to reduce the risks of exploring for more and more subtle hydrocarbon traps. Despite a large number of existing wells in the area studied in this paper, the depositional environments and the stratigraphic architecture were still poorly known. In order to improve the geological understanding, we propose a workflow to assess the remaining reservoir potential of mature hydrocarbon areas, integrating cores, cuttings, well-logs, biostratigraphy and seismic data. This workflow was developed for and is exemplified with the northwest of the Lower Saxony Basin (LSB), a mature hydrocarbon province in northwest Germany, but can be applied in a similar fashion to other areas. Systematic integration of lithofacies analysis, chrono- and sequence stratigraphy, combined with electrofacies analysis and modern digital methods like neural network-based lithology determination and 3D facies modelling provides a high-resolution understanding of the spatial facies and reservoir architecture in the study area. Despite widely correlatable litho-units in the Upper Jurassic and Lower Cretaceous in the LSB, complex heterogeneous sedimentary systems can be found in the basin's marginal parts. Two new play types were determined in the study area, showing a remaining potential for stratigraphic hydrocarbon traps. The results of this exploration scale study also provide the basis for re-evaluations on a field development scale. On a basin scale, this study may encourage further data acquisition and re-evaluations to discover previously unknown reservoirs.

  5. Effects of climate change on spring wheat phenophase and water requirement in Heihe River basin, China

    Science.gov (United States)

    Han, Dongmei; Yan, Denghua; Xu, Xinyi; Gao, Yu

    2017-02-01

    Climate change has significantly altered the temperature rhythm which is a key factor for the growth and phenophase of the crop. And temperature change further affects crop water requirement and irrigation system. In the north-west of China, one of the most important crop production bases is Heihe River basin where the observed phenological data is scarce. This study thus first adopted accumulated temperature threshold (ATT) method to define the phenological stages of the crop, and analysed the effect of climate change on phenological stages and water requirement of the crop during growing season. The results indicated the ATT was available for the determination of spring wheat phenological stages. The start dates of all phenological stages became earlier and the growing season length (days) was reduced by 7 days under climate change. During the growing season, water requirement without consideration of phenophase change has been increased by 26.1 mm, while that with consideration of phenophase change was featured in the decrease of water requirement by 50 mm. When temperature increased by 1°C on average, the changes were featured in the 2 days early start date of growing season, 2 days decrease of growing season length, and the 1.4 mm increase of water requirement, respectively.

  6. Emergy evaluation of agricultural sustainability of Northwest China before and after the grain-for-green policy

    International Nuclear Information System (INIS)

    Wang, Xiuhong; Shen, Jianxiu; Zhang, Wei

    2014-01-01

    China’s grain-for-green policy (GFGP) was implemented with the goal of improving ecological security. Consequently, agricultural energy and agrochemical inputs have been significantly increased to improve food security and to increase the income of farmers in the regions where the GFGP was implemented. In analysis of the sustainability of the agricultural system affected by the GFGP, it is essential to consider both economic profitability and environmental sustainability. Using Yanchi County as a case study area, this study used an emergy synthesis to examine the sustainability of the agricultural system before and after the GFGP in Northwest China. We found that the total emergy input and energy output of the agricultural system in the study area increased from 1991 to 2008; however, the sustainability of the system declined, and this decline was especially evident after the GFGP was launched in 2001. Increasing inputs of non-renewable purchased resources will not only reduce the effectiveness of the GFGP in Northwest China, but also hinder the implementation of the energy-saving and emission-reduction policy that China launched in 2005. We suggest that sustainable agricultural development in Northwest China should be based on effective use of renewable resources and development of a low-carbon agricultural economy. - Highlights: • The total emergy input and energy output of the study system increased from 1991 to 2008. • The change of each emergy index was more evident after the GFGP launched in 2001. • The increase in input of non-renewable purchased resources will gradually reduce the function of the GFGP in West China. • Agricultural development in West China should be based on organic agriculture

  7. Air Pollution Over the Ganges Basin and Northwest Bay of Bengal in the Early Postmonsoon Season Based on NASA MERRAero Data

    Science.gov (United States)

    Kishcha, Pavel; Da Silva, Arlindo M.; Starobinets, Boris; Alpert, Pinhas

    2014-01-01

    The MERRA Aerosol Reanalysis (MERRAero) has been recently developed at NASA's Global Modeling Assimilation Office. This reanalysis is based on a version of the Goddard Earth Observing System-5 (GEOS-5) model radiatively coupled with Goddard Chemistry, Aerosol, Radiation, and Transport aerosols, and it includes assimilation of bias-corrected aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on both Terra and Aqua satellites. In October over the period 2002-2009, MERRAero showed that AOT was lower over the east of the Ganges basin than over the northwest of the Ganges basin: this was despite the fact that the east of the Ganges basin should have produced higher anthropogenic aerosol emissions because of higher population density, increased industrial output, and transportation. This is evidence that higher aerosol emissions do not always correspond to higher AOT over the areas where the effects of meteorological factors on AOT dominate those of aerosol emissions. MODIS AOT assimilation was essential for correcting modeled AOT mainly over the northwest of the Ganges basin, where AOT increments were maximal. Over the east of the Ganges basin and northwest Bay of Bengal (BoB), AOT increments were low and MODIS AOT assimilation did not contribute significantly to modeled AOT. Our analysis showed that increasing AOT trends over northwest BoB (exceeding those over the east of the Ganges basin) were reproduced by GEOS-5, not because of MODIS AOT assimilation butmainly because of the model capability of reproducing meteorological factors contributing to AOT trends. Moreover, vertically integrated aerosol mass flux was sensitive to wind convergence causing aerosol accumulation over northwest BoB.

  8. First report of Toxoplasma gondii infection in market-sold adult chickens, ducks and pigeons in northwest China

    Directory of Open Access Journals (Sweden)

    Cong Wei

    2012-06-01

    Full Text Available Abstract Background Toxoplasma gondii infection is a global concern, affecting a wide range of warm-blooded animals and humans worldwide, including poultry. Domestic and companion birds are considered to play an important role in the transmission of T. gondii to humans and other animals. However, little information on T. gondii infection in domestic birds in Lanzhou, northwest China was available. Therefore, this study was performed to determine the seroprevalence of T. gondii infection in domestic birds in Lanzhou, northwest China. Methods In the present study, the seroprevalence of T. gondii antibodies in 413 (305 caged and 108 free-range adult chickens, 334 (111 caged and 223 free-range adult ducks and 312 adult pigeons in Lanzhou, northwest China, were examined using the modified agglutination test (MAT. Results 30 (7.26% chickens, 38 (11.38% ducks and 37 (11.86% pigeons were found to be positive for T. gondii antibodies at the cut-off of 1:5. The prevalences in caged and free-range chickens were 6.23% and 10.19% respectively, however, statistical analysis showed that the difference was not significant (P > 0.05. The seroprevalences in caged and free-range ducks were 6.31% and 13.90% respectively, but the difference was not statistically significant (P > 0.05. Conclusions The results of the present survey indicated the presence of T. gondii infection in adult chickens, ducks and pigeons sold for meat in poultry markets in Lanzhou, northwest China, which poses a potential risk for T. gondii infection in humans and other animals in this region. This is the first seroprevalence study of T. gondii infection in domestic birds in this region.

  9. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China

    OpenAIRE

    Liu, Xin; Wang, Sufen; Xue, Han; Singh, Vijay P.

    2015-01-01

    Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigatio...

  10. A Pliocene–Quaternary analogue for ancient epeiric carbonate settings: The Malita intrashelf basin (Bonaparte Basin, northwest Australia)

    OpenAIRE

    Courgeon, Simon; Bourget, Julien; Jorry, Stephan

    2016-01-01

    During the Plio-Quaternary, the Bonaparte Basin is characterized by a very wide (> 600 km, > 370 mi) carbonate platform and 200 km-wide (125 mi-wide) intra-shelf basin (the Malita ISB). Using 3D and 2D seismic data combined with exploration well data, this study characterizes the stratigraphic evolution of the Malita ISB during the last 3.5 million years. Two third-order transgressive sequences can be distinguished. A late Pliocene transgression occurred over an irregular topography resulting...

  11. Evaluating the impacts of slope aspect on forest dynamic succession in Northwest China based on FAREAST model

    Science.gov (United States)

    Hu, Shanshan; Ma, Jianyong; Shugart, Herman H.; Yan, Xiaodong

    2018-03-01

    Mountain forests provide the main water resources and lumber for Northwest China. The understanding of the differences in forests growing among individual slope aspects in mountainous regions is of great significance to the wise management and planning of these natural systems. The aim of this study was to investigate the impacts of slope aspect on forest dynamic succession in Northwest China by using the dynamic forest succession model (FAREAST). First, the simulated forest composition and vertical forest zonation produced by the model were compared against recorded data in three sub-regions of the Altai Mountains. The FAREAST model accurately reproduced the vertical zonation, forest composition, growth curves of the dominant species (Larix sibirica), and forest biomass in the Altai Mountains. Transitions along the forest zones of the Altai Mountains averaged about a 400 m difference between the northern and southern sites. Biomass for forests on north-facing slopes were 11.0, 15.3 and 55.9 t C ha-1 higher than for south-facing slopes in the Northeast, Central and Southeast sub-regions, respectively. Second, our analyses showed that the FAREAST model can be used to predict dynamic forest succession in Northwest China under the influence of slope and aspect. In the Altai Mountains, the north-facing slopes supported the best forest growth, followed by the west- and east-facing slopes. South-facing slopes consistently exhibited the lowest growth, biomass storage and forest diversity.

  12. An input-output table based analysis on the virtual water by sectors with the five northwest provinces in China

    Science.gov (United States)

    Shi, Chenchen; Zhan, Jinyan

    Virtual water refers to the volumes of water required to produce a commodity or service. It reflects human's actual consumption of water resources and therefore has certain significance in water resources management. Over the years, the concept of virtual water has caught the attentions of water manager and decision maker. In order to utilize this concept, the accounting and estimation of virtual water is the foundation that lies in this issue. Till now, the accounting methods mainly include the method provided by Food and Agriculture Organization of the United Nations (FAO), water footprint and input-output analysis method. In this paper, we chose Northwest China, which is a typical arid region that is facing with rapid economic development, as the study area and built an Input-Output (IO) analysis method to estimate virtual water among different industry sectors in the northwest China. The accounting and estimation results could be used to give suggestions to increase water use efficiency and promote virtual water trade in the study area. Comparison of the proposed method with other prevailing method was also analyzed. The introduced method could be utilized for accounting and estimation of virtual water by sectors, with its superiority in characterizing industrial water consumption and the accounting results could lend certain credence to the water resource management and industrial transformation for the future economic development of northwest China.

  13. Common and Privatized: Conditions for Wise Management of Matsutake Mushrooms in Northwest Yunnan Province, China

    Directory of Open Access Journals (Sweden)

    Xuefei Yang

    2009-12-01

    Full Text Available Since Hardin's (1968 paper on the "Tragedy of the Commons," property rights of common-pool resources have been a central concern for natural resource management scholars. Matsutake, a common-pool resource, is an economically important mushroom in several locations around the world. Driven by growing international demand over the last few decades, matsutake management is a relatively new practice both for local communities and government agencies. In Northwest Yunnan, China, one of the most productive areas for matsutake globally, numerous local practices and systems have emerged in the last two to three decades. In this study, we investigate the differences between management systems in eight communities and the factors associated with them. The methods used for field research included key-informant interviews, household surveys, and questionnaires. Three main management patterns were identified through use of statistical clustering based on indicators such as physical environment, resource characteristics, tenure arrangements, regulations and implementation, harvesting behavior, income, and market regulation. It was found that private access - the principal characteristic of which is the exclusive use of resources - results in more income at lower labor cost per household than either of the other open-access management patterns. Even though under the context of ongoing Second Forest Tenure Reform in China - in which collective forest privatization is the key task - application of private-access regimes is limited because of site conditions including physical, institutional, and market environments. Common-access management systems have advantages in terms of managing conflict and balancing equity needs. No matter the type of access right, the key issue for wise matsutake management is institutional. Locally rooted innovative strategies should be encouraged, and institutional capacity building should be carried out to support innovations in

  14. Geological evolution history of petroliferous basins on continental shelf of China

    Energy Technology Data Exchange (ETDEWEB)

    Lidesheng

    1983-03-01

    Coastlines of China are about 18,000 km (11,118 mi) in length, and their aggregate continental shelf area within 200 m (656 ft) seawater depth is more than one million km/sup 2/ (386,102 mi/sup 2/). Recent geophysical exploration work and numerous petroleum drilling records are available and give a general understanding of the geological evolution history of these petroliferous basins. There are two tectonic types of basins distributed on the continental shelf areas: the tectonic types of Bohai Gulf, South Yellow Sea, and Beibu Gulf basins are the intraplate polyphase rifting-depression basins; the East China Sea, Pearl River mouth, and Yingge Sea basin are the epicontinental rifting-depression basins. They are believed to be extensional in origin. Because of the severe convergence of Indian plate with Eurasia plate, there has been produced NNE-spreading movement of the South China Sea basin, which permits two triple junctions on its northern margins. The extension mechanism could be derived from the rising of an upper mantle plume to produce two NNE weak fracturing zones, resulting in a series of intraplate and epicontinental rifting-depression basins. The depositional models and sea-level variations of these basins are interpreted from the drilling records and seismic profiles. They can be explained by the tectono-eustatic changes in sea level and Cenozoic climate changes of China.

  15. Why was the arid and semiarid northwest China getting wetter in the recent decades?

    Science.gov (United States)

    Peng, Dongdong; Zhou, Tianjun

    2017-09-01

    The arid and semiarid northwest China has experienced a significant wetting trend in summer during 1961-2010, but the reasons remain ambiguous. In this study, moisture budget analysis is employed to quantify the contributions of different factors to the wetting trend. The results show that more than 50% of the increasing precipitation is balanced by the increased evaporation. The convergence of moisture flux (the sum of horizontal moisture advection and wind convergence terms) has a significant positive contribution to the wetting trend. The increased net surface radiation, which is contributed by the increased downward longwave radiation, supplies more energy to favor the evaporation process of vaporization. The moisture flux convergence is further separated into thermodynamic component in association with changes in specific humidity and dynamic component due to changes in atmospheric circulation. The thermodynamic contribution to the wetting trend is induced by the increased specific humidity which is associated with enhanced evaporation. The dynamic contribution is dominated by an anomalous cyclone over central Asia. The anomalous cyclone is related with intensified horizontal vorticity advection which is associated with a significant southward displacement of Asian subtropical westerly jet. The results indicate that the changes of evaporation against the background of global warming deserve more attention in projecting the climate change in arid and semiarid regions.

  16. AHP 46: AN UNEXPECTED GIFT FROM THE GODS: BOYHOOD IN NORTHWEST CHINA

    Directory of Open Access Journals (Sweden)

    Yang Jialiang 杨佳亮

    2017-04-01

    Full Text Available My name is Chao. I'm an ordinary person from a poor mountain village in northwest China. Like most other human beings, I often ponder: Why do I exist? How should I live? What is the meaning of my life? I believe my life is not worthless. Everyone should be appreciated and each of us should be valued as a wonderful individual. This is why I wrote this book - to share with others the narrative of my life; to allow others to know another human being's life story. My parents had two children. Brother was born in 1982 and 10 years later in 1992, I was born. Mother was then 38 and Father was 42. I was an accident. My parents had decided to give me away because they were afraid of violating the one-child policy and because they were so poor. They had decided to give me to a rich family who would in return give them a truck. However, at that time Brother was very attached to me. He cried a lot when he heard that my parents would give me away. My parents then decided to keep me no matter the difficulties they faced.

  17. Land surface temperature retrieval from MODIS and VIRR data in northwest China

    International Nuclear Information System (INIS)

    Wang, L J; Zuo, H C; Ren, P C; Qiang, B

    2014-01-01

    By using the Gulang Heterogeneous Underlying Surface Layer Experiment (GHUSLE) data, the accuracy of land surface temperature (LST) in Northwest China retrieved by the Moderate-Resolution Imaging Spectroradiometer(MODIS) and Visible and InfraRed Radiometer(VIRR) data is verified. Furthermore, a new LST algorithm for heterogeneous underlying surface is developed and the LST retrieved by the two remote sensing data using three algorithms are compared with the observed data. Results suggest that the new algorithm is the best one in the case of heterogeneous underlying surface, Kerr algorithm accuracy is not satisfying and Becker algorithm is ranked just ahead Kerr algorithm. Especially, the differences in retrieval accuracy among them are more obvious when using the VIRR data. Compared with the observed LST, the root mean square errors of the LST retrieved by MODIS and VIRR data are the least when using the new algorithm, the specific values are 2.55 K and 3.78 K, respectively. The LST retrieved by MODIS data are closer to observed values and higher than its counterpart retrieved by VIRR data. When the new LST retrieval algorithm used, the LST retrieved by MODIS and VIRR data are the closest

  18. Seroprevalence and Risk Factors of Chlamydia abortus Infection in Tibetan Sheep in Gansu Province, Northwest China

    Directory of Open Access Journals (Sweden)

    Si-Yuan Qin

    2014-01-01

    Full Text Available Chlamydia abortus, an important pathogen in a variety of animals, is associated with abortion in sheep. In the present study, 1732 blood samples, collected from Tibetan sheep between June 2013 and April 2014, were examined by the indirect hemagglutination (IHA test, aiming to evaluate the seroprevalence and risk factors of C. abortus infection in Tibetan sheep. 323 of 1732 (18.65% samples were seropositive for C. abortus antibodies at the cut-off of 1 : 16. A multivariate logistic regression analysis was used to evaluate the risk factors associated with seroprevalence, which could provide foundation to prevent and control C. abortus infection in Tibetan sheep. Gender of Tibetan sheep was left out of the final model because it is not significant in the logistic regression analysis (P>0.05. Region, season, and age were considered as major risk factors associated with C. abortus infection in Tibetan sheep. Our study revealed a widespread and high prevalence of C. abortus infection in Tibetan sheep in Gansu province, northwest China, with higher exposure risk in different seasons and ages and distinct geographical distribution.

  19. Seroprevalence and risk factors of Chlamydia abortus infection in Tibetan sheep in Gansu province, northwest China.

    Science.gov (United States)

    Qin, Si-Yuan; Yin, Ming-Yang; Cong, Wei; Zhou, Dong-Hui; Zhang, Xiao-Xuan; Zhao, Quan; Zhu, Xing-Quan; Zhou, Ji-Zhang; Qian, Ai-Dong

    2014-01-01

    Chlamydia abortus, an important pathogen in a variety of animals, is associated with abortion in sheep. In the present study, 1732 blood samples, collected from Tibetan sheep between June 2013 and April 2014, were examined by the indirect hemagglutination (IHA) test, aiming to evaluate the seroprevalence and risk factors of C. abortus infection in Tibetan sheep. 323 of 1732 (18.65%) samples were seropositive for C. abortus antibodies at the cut-off of 1:16. A multivariate logistic regression analysis was used to evaluate the risk factors associated with seroprevalence, which could provide foundation to prevent and control C. abortus infection in Tibetan sheep. Gender of Tibetan sheep was left out of the final model because it is not significant in the logistic regression analysis (P > 0.05). Region, season, and age were considered as major risk factors associated with C. abortus infection in Tibetan sheep. Our study revealed a widespread and high prevalence of C. abortus infection in Tibetan sheep in Gansu province, northwest China, with higher exposure risk in different seasons and ages and distinct geographical distribution.

  20. Characteristics of meteorological drought pattern and risk analysis for maize production in Xinjiang, Northwest China

    Science.gov (United States)

    Li, Cheng; Wang, Ranghui; Ning, Husen; Luo, Qinghong

    2017-08-01

    Xinjiang is an important maize cultivation area in Northwest China. Investigating the relationship between meteorological drought and climate-driven maize yield can help to mitigate the negative impacts of drought on agricultural production in Xinjiang. In this study, multi-source data, including meteorological, agricultural, and socio-economic data, are collected to analyze the spatiotemporal patterns of drought and assess drought disaster risk. The standardized precipitation evapotranspiration index is calculated to classify different drought grades in the study area. The main results are as follows: (1) the relationship between drought and climate-driven maize yield is determined using a stepwise regression analysis, which indicates that drought conditions occurring from May to July are crucial for the yield in Xinjiang; (2) the modified Mann-Kendall test detects that the frequency-intensity-coverage of drought from May to July shows a decreasing tendency as a whole in the study area; (3) the correlation analysis shows that the multivariate ENSO index may be the dominant force in regional drought evolution; and (4) a drought disaster risk assessment system is constructed based on principles of natural disaster management. The drought disaster risk is higher in southwestern and northwestern Xinjiang, areas that should deserve more attention.

  1. Assessment of groundwater vulnerability in the Yinchuan Plain, Northwest China using OREADIC.

    Science.gov (United States)

    Qian, Hui; Li, Peiyue; Howard, Ken W F; Yang, Chao; Zhang, Xuedi

    2012-06-01

    Groundwater vulnerability assessments provide a measure of the sensitivity of groundwater quality to an imposed contaminant load and are globally recognized as an essential element of all aquifer management and protection plans. In this paper, the vulnerability of groundwaters underlying the Yinchuan Plain of Northwest China is determined using OREADIC, a GIS-based assessment tool that incorporates the key characteristics of the universally popular DRASTIC approach to vulnerability assessment but has been modified to consider important additional hydrogeological factors that are specific to the region. The results show that areas of high vulnerability are distributed mainly around Qingtongxia City, Wuzhong City, Lingwu City, and Yongning County and are associated with high rates of aquifer recharge, shallow depths to the water table, and highly permeable aquifer materials. The presence of elevated NO (3) (-) in the high vulnerability areas endorses the OREADIC approach. The vulnerability maps developed in this study have become valuable tools for environmental planning in the region and will be used for predictive management of the groundwater resource.

  2. The origin of high hydrocarbon groundwater in shallow Triassic aquifer in Northwest Guizhou, China.

    Science.gov (United States)

    Liu, Shan; Qi, Shihua; Luo, Zhaohui; Liu, Fangzhi; Ding, Yang; Huang, Huanfang; Chen, Zhihua; Cheng, Shenggao

    2018-02-01

    Original high hydrocarbon groundwater represents a kind of groundwater in which hydrocarbon concentration exceeds 0.05 mg/L. The original high hydrocarbon will significantly reduce the environment capacity of hydrocarbon and lead environmental problems. For the past 5 years, we have carried out for a long-term monitoring of groundwater in shallow Triassic aquifer in Northwest Guizhou, China. We found the concentration of petroleum hydrocarbon was always above 0.05 mg/L. The low-level anthropogenic contamination cannot produce high hydrocarbon groundwater in the area. By using hydrocarbon potential, geochemistry and biomarker characteristic in rocks and shallow groundwater, we carried out a comprehensive study in Dalongjing (DLJ) groundwater system to determine the hydrocarbon source. We found a simplex hydrogeology setting, high-level water-rock-hydrocarbon interaction and obviously original hydrocarbon groundwater in DLJ system. The concentration of petroleum hydrocarbon in shallow aquifer was found to increase with the strong water-rock interaction. Higher hydrocarbon potential was found in the upper of Guanling formation (T 2 g 3 ) and upper of Yongningzhen formation (T 1 yn 4 ). Heavily saturated carbon was observed from shallow groundwater, which presented similar distribution to those from rocks, especially from the deeper groundwater. These results indicated that the high concentrations of original hydrocarbon in groundwater could be due to the hydrocarbon release from corrosion and extraction out of strata over time.

  3. Estimation of wind erosion from construction of a railway in arid Northwest China

    Directory of Open Access Journals (Sweden)

    Benli Liu

    2017-06-01

    Full Text Available A state-of-the-art wind erosion simulation model, the Wind Erosion Prediction System and the United States Environmental Protection Agency's AP 42 emission factors formula, were combined together to evaluate wind-blown dust emissions from various construction units from a railway construction project in the dry Gobi land in Northwest China. The influence of the climatic factors: temperature, precipitation, wind speed and direction, soil condition, protective measures, and construction disturbance were taken into account. Driven by daily and sub-daily climate data and using specific detailed management files, the process-based WEPS model was able to express the beginning, active, and ending phases of construction, as well as the degree of disturbance for the entire scope of a construction project. The Lanzhou-Xinjiang High-speed Railway was selected as a representative study because of the diversities of different climates, soil, and working schedule conditions that could be analyzed. Wind erosion from different working units included the building of roadbeds, bridges, plants, temporary houses, earth spoil and barrow pit areas, and vehicle transportation were calculated. The total wind erosion emissions, 7406 t, for the first construction area of section LXS-15 with a 14.877 km length was obtained for quantitative analysis. The method used is applicable for evaluating wind erosion from other complex surface disturbance projects.

  4. [Effects of biological soil crust on soil erodibility in Hilly Loess Plateau region of Northwest China].

    Science.gov (United States)

    Gao, Li-Qian; Zhao, Yun-Ge; Qin, Ning-Qiang; Zhang, Guo-Xiu

    2013-01-01

    Based on the analysis of the effects of biological soil crust (biocrust) in re-vegetated grasslands on soil physical and chemical properties, and by using EPIC estimation model in combining with simulated rainfall trials, this paper studied the effects of biocrust with different biomass and different soil texture on the soil erodibility (K value) in Hilly Loess Plateau Region of Northwest China in different seasons. The results showed biocrust could significantly decrease soil erodibility, with the K value of biocrust soil decreased by about 17%, compared with subsoil. The soil erodibility decreased with the increasing biomass of biocrust. The K value of moss crust soil decreased by 21%, compared with cyanobacteria crust soil. The erodibiliy of biocrust soil differed with different seasons, being significantly higher in rainy season than before or after the rainy season due to the differences in the biological activity of the biocrust organisms. The erodibilty of biocrust soil with different texture also varied significantly, with the K value in the order of sandy loam soil > silt soil > sandy soil. The measurement under simulated rainfall showed that the development of biocrust could decrease the erodibility of biocrust soil by about 90%, compared with that of the subsoil (5-10 cm).

  5. Sources and potential health risk of gas phase PAHs in Hexi Corridor, Northwest China.

    Science.gov (United States)

    Mao, Xiaoxuan; Yu, Zhousuo; Ding, Zhongyuan; Huang, Tao; Ma, Jianmin; Zhang, Gan; Li, Jun; Gao, Hong

    2016-02-01

    Gas phase polycyclic aromatic hydrocarbons (PAHs) in Hexi Corridor, Northwest China were determined during heating and non-heating seasons, respectively, using passive air samplers. Polyurethane foam (PUF) disks were chosen as the sampling medium. Fifteen PAHs out of the 16 PAHs classified by the United States Environmental Protection Agency (U.S. EPA) were detected in this field sampling investigation. The atmospheric levels of sampled PAHs were higher at urban sites than that at rural sites among 14 sampling sites and increased during heating season. The highest concentration (11.34 ng m(-3)) was observed in Lanzhou during the heating season, the capital and largest industrial city of Gansu Province. PAH contamination in air was dominated by three aromatic ring congeners. Possible sources of PAHs were apportioned using PAH species ratios and the principle component analysis (PCA) combined with a multiple linear regression (MLR) method. Fossil fuel consumption was identified to be the predominant source of PAHs over Hexi Corridor, accounting for 43 % of the concentration of total (15) PAHs. Backward and forward trajectory and cluster analysis were also carried out to identify potential origins of PAHs monitored at several urban and rural sites. Lung cancer risk of local residents to gas phase PAHs via inhalation exposure throughout the province was found to be around a critical value of the lung cancer risk level at 10(-6) recommended by the U.S. EPA risk assessment guideline.

  6. Assessment of Paleozoic shale gas resources in the Sichuan Basin of China, 2015

    Science.gov (United States)

    Potter, Christopher J.; Schenk, Christopher J.; Charpentier, Ronald R.; Gaswirth, Stephanie B.; Klett, Timothy R.; Leathers, Heidi M.; Brownfield, Michael E.; Mercier, Tracey J.; Tennyson, Marilyn E.; Pitman, Janet K.

    2015-10-14

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 23.9 trillion cubic feet of technically recoverable shale gas resources in Paleozoic formations in the Sichuan Basin of China.

  7. Geological evolution, regional perspectives and hydrocarbon potential of the northwest Phu Khanh Basin, offshore Central Vietnam

    DEFF Research Database (Denmark)

    Fyhn, Michael Bryld Wessel; Nielsen, Lars H.; Boldreel, Lars Ole

    2009-01-01

    seeps are found at Dam Thi Nai, immediately landward of the basin. Geochemical analyses of the oil seeps indicate the existence of at least two early to peak mature source rocks. Maturation modelling, combined with the seismic analysis, suggests the likely presence of oil kitchens 40-50km downdip...... and subsidence rates increased after the Middle Miocene times due to eastward tilting of Central Vietnam and the adjacent offshore area. Potential direct hydrocarbon indicators (DHIs) in the Phu Khanh Basin include common amplitude anomalies, gas chimney-like features and seafloor gas seeps. In addition, oil...... in the basin, and a fairly simple oil migration route. The basin is probably charged from lacustrine syn-rift mudstones, humic coals and fore-reef marls. Potential reservoirs are turbidite, lowstand delta, shelf and coastal sandstones, as well as platform and reef carbonates and fractured basement. Various...

  8. Achieving Sustainability in a Semi-Arid Basin in Northwest Mexico through an Integrated Hydrologic-Economic-Institutional Model

    Science.gov (United States)

    Munoz-Hernandez, A.; Mayer, A. S.

    2008-12-01

    The hydrologic systems in Northwest Mexico are at risk of over exploitation due to poor management of the water resources and adverse climatic conditions. The purpose of this work is to create and Integrated Hydrologic-Economic-Institutional Model to support future development in the Yaqui River basin, well known by its agricultural productivity, by directing the water management practices toward sustainability. The Yaqui River basin is a semi-arid basin with an area of 72,000 square kilometers and an average precipitation of 527 mm per year. The primary user of water is agriculture followed by domestic use and industry. The water to meet user demands comes from three reservoirs constructed, in series, along the river. The main objective of the integrated simulation-optimization model is to maximize the economic benefit within the basin, subject to physical and environmental constraints. Decision variables include the water allocation to major users and reservoirs as well as aquifer releases. Economic and hydrologic (including the interaction of the surface water and groundwater) simulation models were both included in the integrated model. The surface water model refers to a rainfall-runoff model created, calibrated, and incorporated into a MATLAB code that estimates the monthly storage in the main reservoirs by solving a water balance. The rainfall-runoff model was coupled with a groundwater model of the Yaqui Valley which was previously developed (Addams, 2004). This model includes flow in the main canals and infiltration to the aquifer. The economic benefit of water for some activities such as agricultural use, domestic use, hydropower generation, and environmental value was determined. Sensitivity analysis was explored for those parameters that are not certain such as price elasticities or population growth. Different water allocation schemes were created based on climate change, climate variability, and socio-economic scenarios. Addams L. 2004. Water resource

  9. Evaluation of relative tectonic perturbations of the Kashmir Basin, Northwest Himalaya, India: An integrated morphological approach

    Science.gov (United States)

    Dubey, R. K.; Dar, Javid Ahmad; Kothyari, Girish Ch.

    2017-10-01

    Geomorphic and morphotectonic evaluations of the Kashmir Basin have been carried by implicating different geomorphic indices such as stream-gradient index (SL), hypsometric integral (HI), drainage basin asymmetry (AF), valley floor height and width ratio (Vf), transverse topographic symmetry factor (T), mountain front sinuosity (Smf), drainage basin shape (BS) and sinuosity index (SI) for the categorization of relative index of active tectonics (RIAT) through the use of geographic information systems (GIS) so as to decipher the role of neotectonics in geomorphologic evolution of the basin. The verified RIAT classes through field investigation and validation reveal the traverse of twenty-one active faults in the basin with demarcation of three RIAT classes viz., class-1 (inactive 20.07% of the area), class-2 (moderately active; 36.52% of the area) and class-3 (very active; 43.4% of the area). The observed values of RIAT distribution pattern are well corroborated with field observations. Ultimately, the overall geomorphic outputs and clustering of recent seismicity support the active tectonic control over the Kashmir basin, India.

  10. Apcocynum Pictum and Sustainable Agriculture Along the Tarim River In Arid Northwest, China

    Science.gov (United States)

    Aihemaitijiang, R.

    2014-12-01

    Water scarcity and population increase have been a major limiting factor in oasis development along the Tarim River in Xinjiang, Northwest China which has very continental and dry climate, and all the agriculture and livelihoods depend on glacier melt water from Tarim River. Due to vast land reclamation along the Tarim River to grow cotton, native plant species are facing a severe competition for water, which is essential for their survival. Decreasing river runoff and inefficient water use practices by agriculture and industry has exacerbated already serious situation even worse. In addition, a large influx of migrant famers from Eastern China is being settled in this region to cultivate new agricultural lands that consumed even more water. Under those conditions, the natural riparian vegetation and the irrigation agriculture, especially along the lower reaches, suffers water shortage leading the degradation and economic losses, respectively. Along with the enlargement of irrigation area and periods of water shortage, soil salinization has become a major concern for farmers in the area. Alternative cash crops are much needed to reduce water use, so both native vegetation and human demand for water would be fulfilled. We hypothesized Apocynum Pictum, perennial herb species with multiple uses as potential substitute. Multidisciplinary approach is being used in this study to investigate three related issues to offer a basis for Apocynum's role in sustainable agriculture, such as Biomass production of Apocynum; Water budget of Apocynum; and Economic utilization of Apocynum. A.Pictum is perennial plant distributed in Central Asia and China, which its roots are perennial, while the stems die every year. Thus, A.pictum grow under the arid climate of Central Asia and provide utilization options without irrigation. We initially estimate water requirement for this plant is much less than cotton. In order to validate our hypothesis, we have measured water consumption of the

  11. Neoproterozoic rift basins and their control on the development of hydrocarbon source rocks in the Tarim Basin, NW China

    Science.gov (United States)

    Zhu, Guang-You; Ren, Rong; Chen, Fei-Ran; Li, Ting-Ting; Chen, Yong-Quan

    2017-12-01

    The Proterozoic is demonstrated to be an important period for global petroleum systems. Few exploration breakthroughs, however, have been obtained on the system in the Tarim Basin, NW China. Outcrop, drilling, and seismic data are integrated in this paper to focus on the Neoproterozoic rift basins and related hydrocarbon source rocks in the Tarim Basin. The basin consists of Cryogenian to Ediacaran rifts showing a distribution of N-S differentiation. Compared to the Cryogenian basins, those of the Ediacaran are characterized by deposits in small thickness and wide distribution. Thus, the rifts have a typical dual structure, namely the Cryogenian rifting and Ediacaran depression phases that reveal distinct structural and sedimentary characteristics. The Cryogenian rifting basins are dominated by a series of grabens or half grabens, which have a wedge-shaped rapid filling structure. The basins evolved into Ediacaran depression when the rifting and magmatic activities diminished, and extensive overlapping sedimentation occurred. The distributions of the source rocks are controlled by the Neoproterozoic rifts as follows. The present outcrops lie mostly at the margins of the Cryogenian rifting basins where the rapid deposition dominates and the argillaceous rocks have low total organic carbon (TOC) contents; however, the source rocks with high TOC contents should develop in the center of the basins. The Ediacaran source rocks formed in deep water environment of the stable depressions evolving from the previous rifting basins, and are thus more widespread in the Tarim Basin. The confirmation of the Cryogenian to Ediacaran source rocks would open up a new field for the deep hydrocarbon exploration in the Tarim Basin.

  12. Identifying entry points to improve fertilizer use efficiency in Taihu Basin, China

    NARCIS (Netherlands)

    Ma, Li; Feng, S.; Reidsma, P.; Qu, F.; Heerink, N.

    2014-01-01

    Overuse of fertilizers in China causes environmental problems and high costs for farmers. In this paper we aim to identify entry points to improve fertilizer use efficiency in Taihu Basin, China. We use stochastic frontier analysis to estimate the technical and fertilizer use efficiency of rice

  13. A surprising discovery of American pika sites in the northwest Great Basin

    Science.gov (United States)

    Mackenzie R. Jeffress; K. Jane Van Gunst; Constance I. Millar

    2017-01-01

    Although the American pika (Ochotona princeps) continues to receive attention due to documented declines and range retractions, particularly in the Great Basin, thorough range inventories have yet to be completed in many parts of the region. Here we report on recently discovered populations in northwestern Nevada in areas not suspected to support...

  14. SWAT-simulated hydrological impact of land-use change in the Zanjanrood basin, Northwest Iran

    NARCIS (Netherlands)

    Ghaffari, G.; Ghodousi, J.; Ahmadi, H.; Keesstra, S.D.

    2010-01-01

    Understanding the impacts of land-use changes on hydrology at the watershed scale can facilitate development of sustainable water resource strategies. This paper investigates the hydrological effects of land-use change in Zanjanrood basin, Iran. The water balance was simulated using the Soil and

  15. Tectonic subsidence of the Zhu 1 Sub-basin in the Pearl River Mouth Basin, northern South China Sea

    Science.gov (United States)

    Tang, Xiaoyin; Yang, Shuchun; Zhu, Junzhang; Long, Zulie; Jiang, Guangzheng; Huang, Shaopeng; Hu, Shengbiao

    2017-12-01

    The Pearl River Mouth Basin, which is situated on the northern margin of the South China Sea, has attracted great attention not only because of its tectonic setting but also because of its abundant hydrocarbon resources. We have analyzed the Cenozoic tectonic subsidence history of 4 drilled wells and 43 artificial wells from the Zhu 1 Sub-basin of the Pearl River Mouth Basin by back-stripping, using newly interpreted seismic profiles. We also calculated the average tectonic subsidence rates of the four sags in the Zhu 1 Sub-basin. The rifting and post-rifting stages are separated by abrupt changes in the tectonic subsidence curves and average subsidence rates. In the eastern sags of the Zhu 1 Sub-basin, tectonic subsidence started to slow at ca. 30 Ma, compared with ca. 23.8 Ma in the western sags. This probably corresponds to the timing of break-up and suggests that rifting in the Pearl River Mouth Basin ended earlier in the eastern sags than in the western sags. Anomalously accelerated tectonic subsidence occurred at 17.5-16.4 Ma during the post-rifting stage, with average subsidence rates as high as 301.9 m/Myr. This distinguishes the Pearl River Mouth Basin from classical Atlantic passive continental marginal basins, which demonstrate exponentially decaying post-rift tectonic subsidence.

  16. [Magnetic Responses of Heavy Metals in Street Dust of Typical Mine-Based City, Northwest China].

    Science.gov (United States)

    Nie, Yan; Wang, Xin; Wang, Bo; Xu, Shu-jing; Gao, Fu-yuan; Yu, Ye; Xia, Dun-sheng; Xia, Xin-ming

    2015-09-01

    Magnetic characteristics and heavy metal properties of 43 street dust samples collected from Baiyin City, northwest of China were systematically analyzed. The results revealed that the main magnetic minerals were low-coercivity magnetite and maghemite with coarse pseudo single domain (PSD) and multi-domain (MD) in magnetic grain size. Compared with the domestic comprehensive cities, low frequency magnetic susceptibility(χlf) value of street dust samples in Binyin varied from 43. 75 x 10(-8) m3.kg-1 to 1 340. 08 x 10(-8) m3.kg-1 with the average value of 245. 98 x 10(-8) m3.kg-1, the magnetic mineral content in street dust samples of Binyin was low relatively, hut it varied among distinct districts with industrial district was the highest and the stripe traffic area was more higher than those of other regions(commercial district, new district). Different functional zones of Baiyin had a single pollution source relatively. Additionally, the contribution to strong magnetic minerals was predominated by industrial pollution and the distribution of pollution degrees in Bainyin showed a significant spatial difference. Concentrations of heavy metals(Cu, Pb, Zn) were generally high in Baiyin street dust. The significantly positive correlation between magnetic parameters(χlf, χARM, SIRM, SOFT) and pollution load index(PLI) and their consistent spatial characteristics confirm that magnetic concentration parameters can effectively monitor urban heavy metals pollution and determine the bounds and areas of pollution, providing a valuable tool for further urban pollution control.

  17. [Effects of mulching on soil moisture in a dryland winter wheat field, Northwest China].

    Science.gov (United States)

    Fan, Ying-Dan; Chai, Shou-Xi; Cheng, Hong-Bo; Chen, Yu-Zhang; Yang, Chang-Gang; Huang, Cai-Xia; Chang, Lei; Pang, Lei

    2013-11-01

    This paper studied the effects of different mulching modes on the soil moisture in a semi-arid rainfed area of Loess Plateau, Northwest China. Seven treatments were installed, i. e., mulching plastic film in summer (T1), mulching plastic film in autumn (T2), mulching 5 cm long wheat straw in summer (T3), mulching whole wheat straw in summer (T4), mulching plastic film in summer plus wheat straw (T5), mulching used plastic film after harvest (T6), and un-mulching (CK). In T6, the soil moisture in different layers at different crop growth stages was all higher than that in CK. In the other five mulching treatments, the soil moisture in 0-90 cm layer before flowering stage was obviously higher, but that in 0-90 cm layer after flowering stage and in 90-200 cm layer during the whole growth season was lower than that of CK. The soil moisture in 0-200 cm layer in T6 during the whole growth period was significantly higher than that in CK, with a difference of 0.9%, but the soil moisture in 0-200 cm layer in other mulching treatments was lower. As compared with plastic film mulching, straw mulching increased the soil moisture in 0-200 cm layer. The soil moisture under mulching with used plastic film after harvest was higher than that under mulching with new plastic film. As compared to CK, the grain yield of winter wheat with plastic film mulching was increased by 20.3%-29.0%, and that With straw mulching was increased by 5.0%-16.7%. There was a significant positive correlation between the crop productivity and the soil water consumption during the growth period (r = 0.77*).

  18. Spatiotemporal variability of temperature and precipitation in Gansu Province (Northwest China) during 1951-2015

    Science.gov (United States)

    Wen, Xiaohu; Wu, Xiaoqing; Gao, Meng

    2017-11-01

    Climate change is potentially challenging the sustainable development in many parts of the world, especially the semi-arid and arid regions on the earth. Northwest China (NWC) is one of the most arid areas in East Asia, and Gansu Province is located at the important climate transition zone in NWC. Spatiotemporal variability of both temperature and precipitation were analyzed based on the daily observation dataset at 29 meteorological stations over Gansu during 1951-2015. The Mann-Kendall trend test was utilized to detect monotonic trends in extreme climate indices, mean temperature, and total precipitation. The results revealed that the warming trends were statistically significant at most stations in Gansu, especially at the high altitude stations; however, the change trends in annual and seasonal precipitation over Gansu were not significant as expected. Furthermore, the 29 stations were spatially grouped using hierarchical clustering method. The regional-averaged temperature anomalies also showed a significant warming trend beginning at the end of 1970s. Spatial variations were also observed in the annual and seasonal precipitation over Gansu. In general, precipitation increased in the western part of Gansu while decreased in the eastern part. Additionally, the wavelet analyses revealed that the teleconnection between large scale circulation and summer precipitation varied not only from region to region, but also was different at different time scale and different time periods. Analysis of large-scale atmospheric circulation changes showed that a strengthening anticyclonic circulation, increasing geopotential height and rapid warming over the Eurasian continent were considered to be attributable to climate change in Gansu and even in NWC.

  19. Human paleodiet and animal utilization strategies during the Bronze Age in northwest Yunnan Province, southwest China.

    Directory of Open Access Journals (Sweden)

    Lele Ren

    Full Text Available Reconstructing ancient diets and the use of animals and plants augment our understanding of how humans adapted to different environments. Yunnan Province in southwest China is ecologically and environmentally diverse. During the Neolithic and Bronze Age periods, this region was occupied by a variety of local culture groups with diverse subsistence systems and material culture. In this paper, we obtained carbon (δ13C and nitrogen (δ15N isotopic ratios from human and faunal remains in order to reconstruct human paleodiets and strategies for animal exploitation at the Bronze Age site of Shilinggang (ca. 2500 Cal BP in northwest Yunnan Province. The δ13C results for human samples from Shilinggang demonstrate that people's diets were mainly dominated by C3-based foodstuffs, probably due to both direct consumption of C3 food and as a result of C3 foddering of consumed animals. Auxiliary C4 food signals can also be detected. High δ15N values indicate that meat was an important component of the diet. Analysis of faunal samples indicates that people primarily fed pigs and dogs with human food waste, while sheep/goats and cattle were foddered with other food sources. We compare stable isotope and archaeobotanical data from Shilinggang with data from other Bronze Age sites in Yunnan to explore potential regional variation in subsistence strategies. Our work suggests that people adopted different animal utilization and subsistence strategies in different parts of Yunnan during the Bronze Age period, probably as local adaptations to the highly diversified and isolated environments in the region.

  20. Cooling effect of agricultural irrigation over Xinjiang, Northwest China from 1959 to 2006

    International Nuclear Information System (INIS)

    Han Songjun; Yang Zhiyong

    2013-01-01

    The influences of agricultural irrigation on trends in surface air temperature from 1959 to 2006 over Xinjiang, Northwest China are evaluated using data from 90 meteorological stations. The 90 stations are located in landscapes with markedly different cultivated land uses. The increasing trends in daily average temperature (T a ), maximum temperature (T max ), and minimum temperature (T min ) for May–September (the main growing season) are negatively correlated with cultivated land proportions within 4 km of the meteorological stations, as indicated by year 2000 land use data. The correlations between the trends in T max and cultivated land proportions are the most significant. The trends in T a , T max , and T min for May–September are expected to decrease by −0.018, −0.014, and −0.016 ° C per decade, respectively, along with a 10% increase in cultivated land proportion. As irrigated cultivated land occupies over 90% of total cultivated land, the dependence of temperature trends on cultivated area is attributed to irrigation. The cooling effects on stations with cultivated land proportion larger than 50% are compared to temperature trends in a reference group with cultivated land proportion smaller than 10%. The irrigation expansion from 1959 to 2006 over Xinjiang is found to be associated with cooling of May–September T a , T max , and T min by around −0.15 ° C to −0.10 ° C/decade in the station group with extensive irrigation. Short periods of rapid irrigation expansion co-occurred with the significant cooling of the May–September temperature. (letter)

  1. Does migration benefit the schooling of children left behind?: Evidence from rural northwest China

    Directory of Open Access Journals (Sweden)

    Feng Hu

    2013-07-01

    Full Text Available BACKGROUND While many studies have found that migration can benefit home communities and family members left behind by increasing household income, thus easing liquidity constraints on investment; less is known about how "internal" migration and remittances affect the educational performance of the children who are left behind in the source communities. OBJECTIVE My aim in this paper is to examine the effects of migration on the educational attainment of left-behind rural children in northwest China. To gain a better understanding of whether the educational performance of these children improves or suffers when adult family members migrate, I attempt to disentangle the effects of remittances from the effects of migration. METHODS The data used in this study come from the 2004 wave of the Gansu Survey of Children and Families. To account for the possible endogeneity of migration-related variables, I use the migration network variables to instrument for different migration strategies. RESULTS The results show that the absence of adult household members, including parents, has a negative effect on the educational performance of the children left behind, but that remittances can partially compensate for this loss. Boys' educational performance does not seem to be greatly affected by the migration of adult household members. By contrast, the absence of adult household members is shown to have a large negative effect on girls' educational performance, and the positive effect of remittances is also found to be significant for girls. CONCLUSIONS The findings may be of interest to other developing countries with large internal migration flows and to the relevant policy makers, as the results suggest that remittances sent home by out-migrants may serve as a channel for investing in human capital in the migrants' regions of origin, and especially for investing in the human capital of girls.

  2. Variation characteristics of regional synchronous wind in Hami, Xinjiang of Northwest China

    Science.gov (United States)

    Huang, Linhong; Song, Lili; Li, Gang; Xin, Yu

    2015-04-01

    From several towers in Hami, Xinjiang of Northwest China, built by the national wind power resources professional observation network, we selected three towers with synchronous 10-min average wind speed data for one year (May 2011-April 2012) under strict quality control. The towers are located where large-scale wind power development is projected. We analyzed the frequency and variation of extreme wind speed at low wind condition (LWC), rated wind condition (RWC), and cut-out wind condition (CWC), which may significantly impact the electric power grid configuration in large-scale wind power development. The correlation between duration and frequency of LWC/RWC/CWC is obtained. Major findings are: 1) The frequency of CWC is the lowest among all conditions, its synchronous rate at all three towers tends to be zero, and the frequency of LWC is always greater than that of RWC. 2) Among the three towers, the synchronous rate of RWC steadily increases with height, and LWC differs little between different levels. The synchronous rate of LWC concentrates in winter, while that of RWC mainly occurs in spring and summer. Diurnal variation of LWC/RWC during the entire year is significantly different. 3) During the study year, the longest durations of synchronous LWC and RWC among the three towers are up to 640 and 700 min, respectively. The duration and frequency of LWC/RWC can be quantitatively well described by a logarithmic function. Consequently, the synchronous rates of LWC and RWC over any duration in the region can be easily calculated by using the fitting function equation from observed data. These results are of value to the planning of large-scale wind power transmission and grid dispatching in this area.

  3. Automated detection of cloud and aerosol features with SACOL micro-pulse lidar in northwest China.

    Science.gov (United States)

    Xie, Hailing; Zhou, Tian; Fu, Qiang; Huang, Jianping; Huang, Zhongwei; Bi, Jianrong; Shi, Jinsen; Zhang, Beidou; Ge, Jinming

    2017-11-27

    The detection of cloud and aerosols using a modified retrieval algorithm solely for a ground-based micropulse lidar (MPL) is presented, based on one-year data at the Semi-Arid Climate Observatory and Laboratory (SACOL) site (35.57°N, 104.08°E, 1965.8 m), northwest of China, from March 2011 to February 2012. The work not only identifies atmosphere particle layers by means of the range-dependent thresholds based on elastic scattering ratio and depolarization ratio, but also discriminates the detected layers by combining empirical thresholds of the atmosphere's thermodynamics states and scattering properties and continuous wavelet transform (CWT) analyses. Two cases were first presented in detail that demonstrated that the modified algorithm can capture atmosphere layers well. The cloud macro-physical properties including cloud base height (CBH), cloud geometrical thickness (CGT), and cloud fraction (CF) were then analyzed in terms of their monthly and seasonal variations. It is shown that the maximum/minimum CBHs were found in summer (4.66 ± 1.95km)/autumn (3.34 ± 1.84km). The CGT in winter (1.05 ± 0.43km) is slightly greater than in summer (0.99 ± 0.44km). CF varies significantly throughout year, with the maximum value in autumn (0.68), and a minimum (0.58) in winter, which is dominated by single-layered clouds (81%). The vertical distribution of CF shows a bimodal distribution, with a lower peak between 1 and 4km and a higher one between 6and 9km. The seasonal and vertical variations in CF are important for the local radiative energy budget.

  4. Temporal-Spatial Pattern of Carbon Stocks in Forest Ecosystems in Shaanxi, Northwest China.

    Directory of Open Access Journals (Sweden)

    Gaoyang Cui

    Full Text Available The precise and accurate quantitative evaluation of the temporal and spatial pattern of carbon (C storage in forest ecosystems is critical for understanding the role of forests in the global terrestrial C cycle and is essential for formulating forest management policies to combat climate change. In this study, we examined the C dynamics of forest ecosystems in Shaanxi, northwest China, based on four forest inventories (1989-1993, 1994-1998, 1999-2003, and 2004-2008 and field-sampling measurements (2012. The results indicate that the total C storage of forest ecosystems in Shaanxi increased by approximately 29.3%, from 611.72 Tg in 1993 to 790.75 Tg in 2008, partially as a result of ecological restoration projects. The spatial pattern of C storage in forest ecosystems mainly exhibited a latitude-zonal distribution across the province, increasing from north (high latitude to south (low latitude generally, which signifies the effect of environmental conditions, chiefly water and heat related factors, on forest growth and C sequestration. In addition, different data sources and estimation methods had a significant effect on the results obtained, with the C stocks in 2008 being considerably overestimated (864.55 Tg and slightly underestimated (778.07 Tg when measured using the mean C density method and integrated method, respectively. Overall, our results demonstrated that the forest ecosystem in Shaanxi acted as a C sink over the last few decades. However, further studies should be carried out with a focus on adaption of plants to environmental factors along with forest management for vegetation restoration to maximize the C sequestration potential and to better cope with climate change.

  5. Tectonostratigraphic history of the Neogene Maimará basin, Northwest Argentina

    Science.gov (United States)

    Galli, Claudia I.; Coira, Beatriz L.; Alonso, Ricardo N.; Iglesia Llanos, María P.; Prezzi, Claudia B.; Kay, Suzanne Mahlburg

    2016-12-01

    This paper presents the tectonostratigraphic evolution of the Maimará Basin and explores the relationship between the clastic sediments and pyroclastic deposits in the basin and the evolution of the adjacent orogeny and magmatic arc. The sedimentary facies in this part of the basin include, in ascending order, an ephemeral fluvial system, a deep braided fluvial system and a medial to distal ephemeral fluvial system. We interpret that Maimará Formation accumulated in a basin that has developed two stages of accumulation. Stage 1 extended from 7 to 6.4 Ma and included accelerated tectonic uplift in the source areas, and it corresponds to the ephemeral fluvial system deposits. Stage 2, which extended from 6.4 to 4.8 Ma, corresponds to a tectonically quiescent period and included the development of the deep braided fluvial system deposits. The contact between the Maimará and Tilcara formations is always characterized by a regional unconformity and, in the study area, also shows pronounced erosion. Rare earth element and other chemical characteristics of the tuff intervals in the Maimará Formation fall into two distinct groups suggesting the tuffs were erupted from two distinct late Miocene source regions. The first and most abundant group has characteristics that best match tuffs erupted from the Guacha, Pacana and Pastos Grandes calderas, which are located 200 and 230 km west of the study area at 22º-23º30‧S latitude. The members the second group are chemically most similar to the Merihuaca Ignimbrite from the Cerro Galán caldera 290 km south-southwest of the studied section. The distinctive geochemical characteristics are excellent tools to reconstruct the stratigraphic evolution of the Neogene Maimará basin from 6.4 to 4.8 Ma.

  6. New discovery on geopressured geothermal resources in China - case history from Ying-Qiong Basins, S. China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ji-yang; Xiong Liang-ping [Institute of Geology, Beijing (China)

    1996-12-31

    Geopressured geothermal resources are regarded as a new type of {open_quotes}high-energy-level{close_quotes} geothermal resources. In recent years, this kind of resources has been discovered in Ying-Qiong Basins at the northern margin of South China Sea. The geological environment and tectonic settings, geotemperature and heat flow pattern, high (over) pressure distribution and sedimentation rates of the basins as well as the perspectives of development and utilization of these resources were discussed briefly by the authors.

  7. Trend Patterns of Vegetative Coverage and Their Underlying Causes in the Deserts of Northwest China over 1982-2008.

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    Tianyi Zhang

    Full Text Available We identified the spatiotemporal patterns of the Normalized Difference Vegetation Index (NDVI for the years 1982-2008 in the desert areas of Northwest China and quantified the impacts of climate and non-climate factors on NDVI changes. The results indicate that although the mean NDVI has improved in 24.7% of the study region; 16.3% among the region has been stagnating in recent years and only 8.4% had a significantly increasing trend. Additionally, 45.3% of the region has maintained a stable trend over the study period and 30.0% has declined. A multiple regression model suggests that a wetter climate (quantified by the Palmer Drought Severity Index, PDSI is associated with higher NDVI in most areas (18.1% of significance but these historical changes in PDSI only caused an average improvement of approximately 0.4% over the study region. Contrasting the regression results under different trend patterns, no significant differences in PDSI impacts were detected among the four trend patterns. Therefore, we conclude that climate is not the primary driver for vegetative coverage in Northwest China. Future studies will be required to identify the impacts of specific non-climatic factors on vegetative coverage based on high-resolution data, which will be beneficial in creating an effective strategy to combat the recent desertification trend in China.

  8. Forest Evapotranspiration and Energy Flux Partitioning Based on Eddy Covariance Methods in an Arid Desert Region of Northwest China

    OpenAIRE

    Ma, Xiaohong; Feng, Qi; Su, Yonghong; Yu, Tengfei; Jin, Hua

    2017-01-01

    In this study, the characteristics of energy flux partitioning and evapotranspiration of P. euphratica forests were examined in the extreme arid region of Northwest China. Energy balance closure of the ecosystem was approximately 72% (H + LE = 0.72 ∗ (Rn-G)+7.72, r2=0.79, n=12095), where Rn is the net radiation, G is the soil heat flux, H is the sensible heat flux, and LE is the latent heat flux. LE was the main term of energy consumption at annual time scale because of higher value in the gr...

  9. Gas geochemistry and methane emission from Dushanzi mud volcanoes in the southern Junggar Basin, NW China

    Science.gov (United States)

    Zheng, Guodong; Ma, Xiangxian; Guo, Zhengfu; Hilton, David R.; Xu, Wang; Liang, Shouyun; Fan, Qiaohui; Chen, Wenxing

    2017-11-01

    There are many mud volcanoes in the southern margin of the Junggar Basin, northwest China, of which the Dushanzi area is the most typical and active one, emitting large amount of greenhouse gases associated with water and mud. The emitted gas is dominated by methane (average 90.1%), together with other gases, such as ethane (4.84-5.46%), propane (0.06-0.90%), CO2 (0.67-1.0%), and N2 (2.8-3.3%). The carbon (δ13C1) and hydrogen (δD) isotopic ratios of methane are in the ranges of -40.6‰ to -45.0‰ and -221‰ to -249‰, respectively, whereas carbon isotope ratios of ethane (δ13C2) are -25.2‰ to -27.6‰. Based on δ13C values, the released gas is characterized as a thermogenic coal-type and possibly originated from the middle-low Jurassic coal-bearing sequences according to the gas-source correlation and regional geology. Helium isotopes show a crustal source. The methane flux of Dushanzi mud volcanoes from both macro-seepage (craters/vents) and micro-seepage (ground soil exhalation) ranged over the orders of magnitude, from 0.4-2.7 kg d-1 and 4950 mg m-2 d-1 on average, respectively. Positive CH4 fluxes from dry soil were widespread throughout the investigated areas. The total CH4 emission from Dushanzi mud volcanoes is estimated to be at least 22.6 tons a-1, of which about 89% is from micro-seepage surrounding the mud volcano vents.

  10. Paleoseismic observations along the Langshan range-front fault, Hetao Basin, China: Tectonic and seismic implications

    Science.gov (United States)

    Dong, Shaopeng; Zhang, Peizhen; Zheng, Wenjun; Yu, Zhongyuan; Lei, Qiyun; Yang, Huili; Liu, Jinfeng; Gong, Huilin

    2018-04-01

    The Langshan range-front fault (LRF) is an active Holocene normal fault that borders Langshan Mountain and the Hetao Basin, northwest of the Ordos Plateau, China. In this study, paleoseismic trenching was undertaken at three sites (North-South): Dongshen village (TC1), Qingshan (TC2), and Wulanhashao (TC3). The paleoevents ED1, ED2, ED3 from TC1 were constrained to 6.0 ± 1.3, 9.6 ± 2.0, and 19.7 ± 4.2 ka, respectively. The single paleoevent (EQ1) from TC2 was constrained to about 6.7 ± 0.1 ka, and the paleoevents EW1, EW2, and EW3 from TC3 were constrained to 2.3 ± 0.4, 6.0 ± 1.0, and before 7.0 ka, respectively. With reference to previous research, the Holocene earthquake sequence of the LRF can be established as 2.30-2.43 (E1), 3.06-4.41 (E2), 6.71-6.80 (E3), 7.60-9.81 (E4), and 19.70 ± 4.20 (E5) ka BP. Events E1, E3, and E4 might have been caused by events with magnitudes of Mw 7.6-7.8 that ruptured the entire LRF. Event E2 might have been smaller magnitude, about M7.0, and ruptured only a portion of the fault. The vertical slip rate of the LRF at the Qingshan site is inferred as 0.9 or 1.4-1.6 mm/year in the last 6.8 ka. The slip rate at Wulanhashao is considered to have been close to, but not fault. Although the possibility of missing events in Late Pleistocene can not be dismissed, we argue the Holocene paleoearthquake history is complete, indicating an average recurrence interval of 2500 years.

  11. Stable isotope and hydrochemical evolution of groundwater in the semi-arid Hamersley Basin of subtropical northwest Australia

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    Dogramaci, Shawan; Skrzypek, Grzegorz; Dodson, Wade; Grierson, Pauline F.

    2012-12-01

    SummaryThe Hamersley Basin, in the semi-arid Pilbara region of northwest Australia, is currently subject to increasing pressure from altered hydrology associated with mining activities as well as water abstraction for regional development. Sustainable water management across the region must be underpinned by an understanding of the factors that constrain water supply in arid zones. We measured the amount and isotopic signature of individual rainfall events over three consecutive years (2009-2011) to determine the likely processes that control surface water pools in streams and groundwater recharge across the Hamersley Basin. We also measured concentrations of ions (in particular bromide and chloride) to define and quantify sources of major recharge. Stable isotope composition of precipitation across the basin forms a Local Meteoric Water Line (LMWL) defined by the equation: δ2H = 7.03 ± 0.17 × δ18O + 4.78 ± 1.45. Thus, the slope of the LMWL was similar to the Global Meteoric Water Line (GMWL). However, the intercept of the LMWL was significantly different to the GMWL, which is attributable to the amount or "rainout" effect. The stable isotope composition of rainfall events was highly variable and dependent on event size. However, the δ2H and δ18O values of fresh groundwater from the alluvium and fractured aquifers were similar and characterised by a very narrow range (alluvium aquifer δ18O -8.02 ± 0.83‰, δ2H -55.6 ± 6.0‰, n = 65; fractured aquifer δ18O -8.22 ± 0.70‰, δ2H -56.9 ± 5.0‰, n = 207). Our findings suggest that intense rainfall events of >20 mm with limited evaporation prior to infiltration contribute most to recharge. In contrast, the δ2H and δ18O values and chemical composition of the relatively saline groundwater in the terminal Fortescue Marsh suggest a combination of evaporation and cyclic drying and wetting of the marsh surface prior to recharge. Saline groundwater samples were more 18O enriched than fresh groundwater; δ2H

  12. Effect of Downscaled Forcings and Soil Texture Properties on Hyperresolution Hydrologic Simulations in a Regional Basin in Northwest Mexico

    Science.gov (United States)

    Ko, A.; Mascaro, G.; Vivoni, E. R.

    2017-12-01

    Hyper-resolution ( 10 km) scales. In this study, we address some of the challenges by applying a parallel version of the Triangulated Irregular Network (TIN)-based Real Time Integrated Basin Simulator (tRIBS) to the Rio Sonora Basin (RSB) in northwest Mexico. The RSB is a large, semiarid watershed ( 21,000 km2) characterized by complex topography and a strong seasonality in vegetation conditions, due to the North American monsoon. We conducted simulations at an average spatial resolution of 88 m over a decadal (2004-2013) period using spatially-distributed forcings from remotely-sensed and reanalysis products. Meteorological forcings were derived from the North American Land Data Assimilation System (NLDAS) at the original resolution of 12 km and were downscaled at 1 km with techniques accounting for terrain effects. Two grids of soil properties were created from different sources, including: (i) CONABIO (Comisión Nacional para el Conocimiento y Uso de la Biodiversidad) at 6 km resolution; and (ii) ISRIC (International Soil Reference Information Centre) at 250 m. Time-varying vegetation parameters were derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) composite products. The model was first calibrated and validated through distributed soil moisture data from a network of 20 soil moisture stations during the monsoon season. Next, hydrologic simulations were conducted with five different combinations of coarse and downscaled forcings and soil properties. Outputs in the different configurations were then compared with independent observations of soil moisture, and with estimates of land surface temperature (1 km, daily) and evapotranspiration (1 km, monthly) from MODIS. This study is expected to support the community involved in hyper-resolution hydrologic modeling by identifying the crucial factors that, if available at higher resolution, lead to the largest improvement of the simulation prognostic capability.

  13. Correlation between seismicity and geomorphology in Dingxi Basin, Gansu Province, China

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    Li Xue

    2013-01-01

    Full Text Available A M6.6 earthquake occurred on July 22, 2013 at Dingxi Basin in Gansu Province within the tectonially expanding northeastern margin of the Qinghai-Tibet Plateau. We analyzed the geomorphological features of the Dingxi Basin by using remote sensing technology and compared them with local seismic activity. We found that most of the river basins are at the robust stage of development and that the major local rivers and the development of some basins boundaries are controlled by the seismic faults. Among four zones identified to have significant tectonic activities, the northwestly-oriented one located in the south has the highest seismic activity, and it is where the M6. 6 earthquake occurrred.

  14. [Mechanisms of grass in slope erosion control in Loess sandy soil region of Northwest China].

    Science.gov (United States)

    Zhao, Chun-Hong; Gao, Jian-En; Xu, Zhen

    2013-01-01

    By adopting the method of simulated precipitation and from the viewpoint of slope hydrodynamics, in combining with the analysis of soil resistance to erosion, a quantitative study was made on the mechanisms of grass in controlling the slope erosion in the cross area of wind-water erosion in Loess Plateau of Northwest China under different combinations of rainfall intensity and slope gradient, aimed to provide basis to reveal the mechanisms of vegetation in controlling soil erosion and to select appropriate vegetation for the soil and water conservation in Loess Plateau. The grass Astragalus adsurgens with the coverage about 40% could effectively control the slope erosion. This grass had an efficiency of more than 70% in reducing sediment, and the grass root had a greater effect than grass canopy. On bare slope and on the slopes with the grass plant or only the grass root playing effect, there existed a functional relation between the flow velocity on the slopes and the rainfall intensity and slope gradient (V = DJ(0.33 i 0.5), where V is flow velocity, D is the comprehensive coefficient which varies with different underlying surfaces, i is rainfall intensity, and J is slope gradient). Both the grass root and the grass canopy could markedly decrease the flow velocity on the slopes, and increase the slope resistance, but the effect of grass root in decreasing flow velocity was greater while the effect in increasing resistance was smaller than that of grass canopy. The effect of grass root in increasing slope resistance was mainly achieved by increasing the sediment grain resistance, while the effect of canopy was mainly achieved by increasing the slope form resistance and wave resistance. The evaluation of the soil resistance to erosion by using a conceptual model of sediment generation by overland flow indicated that the critical shear stress value of bare slope and of the slopes with the grass plant or only the grass root playing effect was 0.533, 1.672 and 0

  15. Prevalence and associated factors of corneal blindness in Ningxia in northwest China

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    Xun-Lun Sheng

    2014-06-01

    Full Text Available AIM:To describe the prevalence and demographic characteristics of corneal blindness in an urban and rural region of Ningxia, located in the northwest part of China.METHODS:A stratified, randomized sampling procedure was employed in the study, including urban and rural area of all age group. Visual acuity, anterior segment and ocular fundus were checked. Related factor of corneal disease, including age, gender, education status, ethnic group, location and occupation, were identified according to uniform customized protocol. An eye was defined to be corneal blindness if the visual acuity was <20/400 due to a corneal disease.RESULTS:Three thousand individuals (1290 from urban area and 1710 from rural area participated in the investigation, with a response rate of 80.380%. The prevalence of corneal blindness was 0.023% in both eyes and 0.733% in at least one eye. The blindness in at least one eye with varied causes was present in 106 participants (3.533% and in bilateral eyes in 34 participants (1.133%. The corneal diseases accounted for 20.754% of blindness in at least one eye and 20.588% of bilateral blindness. The prevalence of corneal disease was higher in older and Han ethnic group, especially those who occupied in agriculture and outdoor work. People with corneal blindness were more likely to be older and lower education. Rural population were more likely to suffer from bilateral corneal blindness than the urban population in ≥59-year group (χ2=6.716, P=0.019. Infectious, trauma and immune corneal disease were the three leading causes of corneal disease. Trauma corneal disease was more likely leading to blindness in one eye. However, infectious and immune corneal diseases make more contribution to the bilateral corneal blindness.CONCLUSION: Corneal blindness is a significant burden of in Ningxia population, encompassing a variety of corneal infections and trauma; the majority of those were avoidable. Health promotion strategies and good

  16. Source apportionment of carbonaceous aerosols in a megacity of northwest China: insights from radiocarbon measurement

    Science.gov (United States)

    Ni, Haiyan; Huang, Rujin; Dusek, Ulrike

    2017-04-01

    Fine particulate matter (PM2.5) samples were collected from 5 July 2008 to 27 June 2009 at Xi'an, a very polluted megacity in Northwest China. The 24 h averaged PM2.5concentrations (ranged from 32 μg m-3 to 339 μg m-3) were 1-14 times higher than the WHO guideline for 24 h PM2.5(25 μg m-3). In this work, we unambiguously quantify fossil (e.g., vehicle emissions, coal burning etc.) and non-fossil (e.g., biomass burning, cooking, biogenic emissions etc.) contributions to organic carbon (OC) and elemental carbon (EC) of PM2.5using radiocarbon (14C) measurement. In addition, we measured PM2.5 major components and source markers, including OC and EC, ions, trace elements, polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (o-PAHs), anhydrous sugars and hopanes. The preliminary results of radiocarbon measurements in OC and EC show that the annual mean contributions from fossil-fuel combustion to EC was 76 ± 8% (6 ± 2 μg m-3). The remaining 24 ± 8% (2 ± 1 μg m-3) was attributed to biomass burning, with higher contribution in the cold period (˜33%) compared to the warm period (˜21%), due to enhanced emissions from local biomass burning activities in winter. In contrast with EC, OC was dominated by non-fossil sources, with an annual average of 54 ± 8 % (13 ± 10 μg m-3). Clear seasonal variations were seen in OC concentrations both from fossil fuel (OCff), and from non-fossil sources (OCnf), with maxima in the cold period and minima in the warm period, because of enhanced fossil and non-fossil activities in winter, mainly biomass burning and domestic coal burning. Further source apportionment of OC, including primary/secondary fossil OC, primary/secondary non-fossil OC, will be conducted by combining 14C results with positive matrix factorization (PMF) analysis of organic matter (OM).

  17. Systematic impact assessment on inter-basin water transfer projects of the Hanjiang River Basin in China

    Science.gov (United States)

    Zhou, Yanlai; Guo, Shenglian; Hong, Xingjun; Chang, Fi-John

    2017-10-01

    China's inter-basin water transfer projects have gained increasing attention in recent years. This study proposes an intelligent water allocation methodology for establishing optimal inter-basin water allocation schemes and assessing the impacts of water transfer projects on water-demanding sectors in the Hanjiang River Basin of China. We first analyze water demands for water allocation purpose, and then search optimal water allocation strategies for maximizing the water supply to water-demanding sectors and mitigating the negative impacts by using the Standard Genetic Algorithm (SGA) and Adaptive Genetic Algorithm (AGA), respectively. Lastly, the performance indexes of the water supply system are evaluated under different scenarios of inter-basin water transfer projects. The results indicate that: the AGA with adaptive crossover and mutation operators could increase the average annual water transfer from the Hanjiang River by 0.79 billion m3 (8.8%), the average annual water transfer from the Changjiang River by 0.18 billion m3 (6.5%), and the average annual hydropower generation by 0.49 billion kW h (5.4%) as well as reduce the average annual unmet water demand by 0.40 billion m3 (9.7%), as compared with the those of the SGA. We demonstrate that the proposed intelligent water allocation schemes can significantly mitigate the negative impacts of inter-basin water transfer projects on the reliability, vulnerability and resilience of water supply to the demanding sectors in water-supplying basins. This study has a direct bearing on more intelligent and effectual water allocation management under various scenarios of inter-basin water transfer projects.

  18. Epidermal characters of Tamarix L. (Tamaricaceae from Northwest China and their taxonomic and palaeogeographic implications

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    Jian-Wei Zhang

    2018-04-01

    implications of Tamarix in the Late Cenozoic of Northwest China are also discussed. Keywords: Anatomy, Arid region, Epidermis, Ecological adaptation, Phylogenetic evolution, Tamarix, Northwest China

  19. Quantifying the intra-annual uncertainties in climate change assessment over 10 sub-basins across the Pacific Northwest US

    Science.gov (United States)

    Ahmadalipour, Ali; Moradkhani, Hamid; Rana, Arun

    2017-04-01

    Uncertainty is an inevitable feature of climate change impact assessments. Understanding and quantifying different sources of uncertainty is of high importance, which can help modeling agencies improve the current models and scenarios. In this study, we have assessed the future changes in three climate variables (i.e. precipitation, maximum temperature, and minimum temperature) over 10 sub-basins across the Pacific Northwest US. To conduct the study, 10 statistically downscaled CMIP5 GCMs from two downscaling methods (i.e. BCSD and MACA) were utilized at 1/16 degree spatial resolution for the historical period of 1970-2000 and future period of 2010-2099. For the future projections, two future scenarios of RCP4.5 and RCP8.5 were used. Furthermore, Bayesian Model Averaging (BMA) was employed to develop a probabilistic future projection for each climate variable. Results indicate superiority of BMA simulations compared to individual models. Increasing temperature and precipitation are projected at annual timescale. However, the changes are not uniform among different seasons. Model uncertainty shows to be the major source of uncertainty, while downscaling uncertainty significantly contributes to the total uncertainty, especially in summer.

  20. Variations of Ecosystem Service Value in Response to Land-Use Change in the Kashgar Region, Northwest China

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    Aynur Mamat

    2018-01-01

    Full Text Available Increasing anthropogenic activities have significantly altered ecosystems in arid oasis regions. Estimating the impact on a wide range of ecosystem services is important for decision making and the sustainable development of these regions. This study analyzed time-series Landsat data to determine the influences of oasis land-use changes on the ecosystem services in the Kashgar region in Northwest China. The following results were found. The total value of the ecosystem services in the Kashgar region were approximately $10,845.3, $11,218.6, $10,291.7, and $10,127.3 million in 1986, 1996, 2005, and 2015, respectively. The water supply, waste treatment, biodiversity protection, and recreation and cultural services were the four ecosystem services with the highest service value, contributing 77.05% of the total ecosystem services. The combined contribution rate of food production and raw material value was only about 4.02%, relatively small. The sensitivity analysis indicated that the estimated total ecosystem service value (ESV for this study area was relatively inelastic with respect to the value coefficients. The findings of this study will be crucial for maintaining the stability and sustainable development of the oasis region, where socio-economic development and the integrity of the natural ecosystem complement each other. Furthermore, the results provide a scientific basis for decision makers in land use management, and provide a reference for researchers in the Northwest China.

  1. Chemical, Mechanical, and Durability Properties of Concrete with Local Mineral Admixtures under Sulfate Environment in Northwest China.

    Science.gov (United States)

    Nie, Qingke; Zhou, Changjun; Shu, Xiang; He, Qiang; Huang, Baoshan

    2014-05-13

    Over the vast Northwest China, arid desert contains high concentrations of sulfate, chloride, and other chemicals in the ground water, which poses serious challenges to infrastructure construction that routinely utilizes portland cement concrete. Rapid industrialization in the region has been generating huge amounts of mineral admixtures, such as fly ash and slags from energy and metallurgical industries. These industrial by-products would turn into waste materials if not utilized in time. The present study evaluated the suitability of utilizing local mineral admixtures in significant quantities for producing quality concrete mixtures that can withstand the harsh chemical environment without compromising the essential mechanical properties. Comprehensive chemical, mechanical, and durability tests were conducted in the laboratory to characterize the properties of the local cementitious mineral admixtures, cement mortar and portland cement concrete mixtures containing these admixtures. The results from this study indicated that the sulfate resistance of concrete was effectively improved by adding local class F fly ash and slag, or by applying sulfate resistance cement to the mixtures. It is noteworthy that concrete containing local mineral admixtures exhibited much lower permeability (in terms of chloride ion penetration) than ordinary portland cement concrete while retaining the same mechanical properties; whereas concrete mixtures made with sulfate resistance cement had significantly reduced strength and much increased chloride penetration comparing to the other mixtures. Hence, the use of local mineral admixtures in Northwest China in concrete mixtures would be beneficial to the performance of concrete, as well as to the protection of environment.

  2. Spatiotemporal changes in vegetation net primary productivity in the arid region of Northwest China, 2001 to 2012

    Science.gov (United States)

    Li, Zhen; Pan, Jinghu

    2018-03-01

    Net primary productivity (NPP) is recognized as an important index of ecosystem conditions and a key variable of the terrestrial carbon cycle. It also represents the comprehensive effects of climate change and anthropogenic activity on terrestrial vegetation. In this study, the temporal-spatial pattern of NPP for the period 2001-2012 was analyzed using a remote sensing-based carbon model (i.e., the Carnegie-Ames-Stanford Approach, CASA) in addition to other methods, such as linear trend analysis, standard deviation, and the Hurst index. Temporally, NPP showed a significant increasing trend for the arid region of Northwest China (ARNC), with an annual increase of 2.327 g C. Maximum and minimum productivity values appeared in July and December, respectively. Spatially, the NPP was relatively stable in the temperate and warm-temperate desert regions of Northwest China, while temporally, it showed an increasing trend. However, some attention should be given to the northwestern warm-temperate desert region, where there is severe continuous degradation and only a slight improvement trend.

  3. South China connected to north India in Gondwana: sedimentary basin and detrital provenance analyses

    Science.gov (United States)

    Yao, W.; Li, Z. X.; Li, W. X.; Li, X. H.; Yang, J. H.

    2015-12-01

    The paleoposition of South China during the Ediacaran-Silurian is important for understanding the assembly of Gondwana. We report here the tectonostratigraphic evolution of the Ediacaran-Silurian Nanhua foreland basin in South China, and discuss South China's connection with Gondwana and potential tectonic triggers for both the Wuyi-Yunkai orogeny in South China and the Bhimphedian orogeny in north India. The Nanhua basin was involved in a three-stage evolution, which are: Stage 1 (the Ediacaran-Cambrian) recording the start of tectonic subsidence with turbiditic marine clastic deposition, fed by exotic orogens outboard South China; Stage 2 (the Ordovician to earliest-Silurian) featured by migrating depocentres with dominant shallow marine to deltaic clastic deposition, fed by the local Wuyi-Yunkai orogen; and Stage 3 (the Silurian) showing the arrival of depocentre in the Yangtze Block during the waning stage of the Wuyi-Yunkai orogeny with deltaic deposition in the remanent foreland basin. Detrital zircon analyses of the Ediacaran-Silurian sandstones across the Nanhua basin reveal a prominent age population of 1100-900 Ma (with a peak age at ~980 Ma) and moderate populations of Archean-Paleozoic ages, grossly matching that of crystalline and sedimentary rocks in northern India. Zircon isotopes of the Stage 1 samples suggest three Precambrian episodes of juvenile crustal growth at 3.0 Ga, 2.5 Ga and 1.0 Ga, and a major crustal reworking at 580-500 Ma for the source areas, which are constraint to be northwestern India and its surrounding orogens. Together with other evidence, we propose that South China likely collided with northwestern India during the Gondwana assembly, generated the Bhimphedian orogeny in north India and formed two foreland basins on both the north India and South China sides. Far-field stress of the collision triggered the Ordovician-Silurian Wuyi-Yunkai orogeny in South China. The Stage 2-3 samples in the Nanhua basin of South China were shed

  4. Spatial distribution of soil organic carbon and its influencing factors in desert grasslands of the Hexi Corridor, northwest China.

    Science.gov (United States)

    Wang, Min; Su, Yongzhong; Yang, Xiao

    2014-01-01

    Knowledge of the distribution patterns of soil organic carbon (SOC) and factors that influence these patterns is crucial for understanding the carbon cycle. The objectives of this study were to determine the spatial distribution pattern of soil organic carbon density (SOCD) and the controlling factors in arid desert grasslands of northwest China. The above- and belowground biomass and SOCD in 260 soil profiles from 52 sites over 2.7×10(4) km2 were investigated. Combined with a satellite-based dataset of an enhanced vegetation index during 2011-2012 and climatic factors at different sites, the relationships between SOCD and biotic and abiotic factors were identified. The results indicated that the mean SOCD was 1.20 (SD:+/- 0.85), 1.73 (SD:+/- 1.20), and 2.69 (SD:+/- 1.91) kg m(-2) at soil depths of 0-30 cm, 0-50 cm, and 0-100 cm, respectively, which was smaller than other estimates in temperate grassland, steppe, and desert-grassland ecosystems. The spatial distribution of SOCD gradually decreased from the southeast to the northwest, corresponding to the precipitation gradient. SOCD increased significantly with vegetation biomass, annual precipitation, soil moisture, clay and silt content, and decreased with mean annual temperature and sand content. The correlation between BGB and SOCD was closer than the correlation between AGB and SOCD. Variables could together explain about 69.8%, 74.4%, and 78.9% of total variation in SOCD at 0-30 cm, 0-50 cm, and 0-100 cm, respectively. In addition, we found that mean annual temperature is more important than other abiotic factors in determining SOCD in arid desert grasslands in our study area. The information obtained in this study provides a basis for accurately estimating SOC stocks and assessing carbon (C) sequestration potential in the desert grasslands of northwest China.

  5. Spatial distribution of soil organic carbon and its influencing factors in desert grasslands of the Hexi Corridor, northwest China.

    Directory of Open Access Journals (Sweden)

    Min Wang

    Full Text Available Knowledge of the distribution patterns of soil organic carbon (SOC and factors that influence these patterns is crucial for understanding the carbon cycle. The objectives of this study were to determine the spatial distribution pattern of soil organic carbon density (SOCD and the controlling factors in arid desert grasslands of northwest China. The above- and belowground biomass and SOCD in 260 soil profiles from 52 sites over 2.7×10(4 km2 were investigated. Combined with a satellite-based dataset of an enhanced vegetation index during 2011-2012 and climatic factors at different sites, the relationships between SOCD and biotic and abiotic factors were identified. The results indicated that the mean SOCD was 1.20 (SD:+/- 0.85, 1.73 (SD:+/- 1.20, and 2.69 (SD:+/- 1.91 kg m(-2 at soil depths of 0-30 cm, 0-50 cm, and 0-100 cm, respectively, which was smaller than other estimates in temperate grassland, steppe, and desert-grassland ecosystems. The spatial distribution of SOCD gradually decreased from the southeast to the northwest, corresponding to the precipitation gradient. SOCD increased significantly with vegetation biomass, annual precipitation, soil moisture, clay and silt content, and decreased with mean annual temperature and sand content. The correlation between BGB and SOCD was closer than the correlation between AGB and SOCD. Variables could together explain about 69.8%, 74.4%, and 78.9% of total variation in SOCD at 0-30 cm, 0-50 cm, and 0-100 cm, respectively. In addition, we found that mean annual temperature is more important than other abiotic factors in determining SOCD in arid desert grasslands in our study area. The information obtained in this study provides a basis for accurately estimating SOC stocks and assessing carbon (C sequestration potential in the desert grasslands of northwest China.

  6. [Pollution and Potential Ecology Risk Evaluation of Heavy Metals in River Water, Top Sediments on Bed and Soils Along Banks of Bortala River, Northwest China].

    Science.gov (United States)

    Zhang, Zhao-yong; Abuduwaili, Jilili; Jiang, Feng-qing

    2015-07-01

    This paper focuses on the sources, pollution status and potential ecology risks of heavy metals (Cr, Cu, Hg, As, Cd, Pb, and Zn) in the surface water, top sediment of river bed and soil along banks of Bortala River, which locates in the oasis region of Xinjiang, northwest China. Results showed that: (1) As a whole, contents of 7 tested heavy metals of Bortala River were low, while the maximum values of Hg, Cd, Pb, and Cr in the river water were significantly higher than those of Secondary Category of the Surface Water Quality Standards of People's Republic of China (GB 3838-2002) and Drinking Water Guideline from WHO. Analysis showed that the heavy metals contents of top sediment on river bed and soils along river banks were significantly higher than those of the river water. (Correlation analysis and enrichment factor (EF) calculation showed that in the river water, top sediment on river bed and soils along river banks, Hg, Cd, Pb, and Cr mainly originated from industrial emissions, urban and rural anthropogenic activities, transportation and agricultural production activities; While Cu, Zn, and As mainly originated from natural geological background and soil parent materials. (3) Pollution assessment showed that in three matrices, the single factor pollution index(Pi) and the integrated pollution index (Pz) of 7 heavy metals were all lower than 1, and they all belonged to safe and clean levels. (4) Potential ecology risk evaluation showed that as a whole the single factor potential ecological risk (Eir) and the integrated potential ecology risks (RI) of 7 heavy metals were relatively low, and would not cause threats to the health of water and soil environment of river basin, while the potential ecology risks of Cd, Hg, Pb, and Cr were significantly higher than those of other heavy metals.

  7. Geophysical evidence for fluid flow in the Laminaria High, Bonaparte basin, Northwest shelf of Australia

    Science.gov (United States)

    Abdulkareem, Lamees; Hobbs, Richard; Imber, Jonathan

    2016-04-01

    Seismic amplitude anomalies ("bright spots") can result from changes in acoustic impedance caused by the presence of fluids and/or lateral changes in lithology. In this study, 3D seismic interpretation and well log data is used to investigate the nature and causes of seismic amplitude anomalies within the shallow subsurface on the Laminaria High on the north-west shelf of Australia. Here, the anomalies are associated with active faults that cut the seabed. Previous studies suggest that fault reactivation and fault geometry have an important role in causing hydrocarbon leakage from a deeper reservoir and that bends on the larger faults will influence the localization of shear strain, increasing the risk of leakage. However, these studies did not examine the influence of fault growth during reactivation on fluid migration, or how post-rift and syn-rift sedimentation may have influenced fluid leakage. In our study, preliminary results suggest that not all active faults are associated with amplitude anomalies or dry/partially-filled hydrocarbon traps at depth, implying that there could be a different mechanism for the creation of the amplitude anomaly observed on the Laminaria High. Specifically, these anomalies may be the result of preferential cementation, or the presence of gas trapped within sediments at or near the seabed, possibly originating from gas generation due to biogenic activity in recently deposited sediment. Detailed amplitude maps are extracted from syn- and pre- faulting seismic horizons down to the top reservoir level in order to understand the spatial extent of the high amplitude anomalies within the stratigraphic succession. The first two amplitude maps for the seismic horizons beneath the seabed show high amplitude anomalies associated with the same active faults that are present on the seabed, but with some different characteristics along these faults. Then we extract number of deeper amplitude maps to the top of reservoir, to reveal whether the

  8. Thermal-Mechanical Regime beneath Tarim Basin, Northwestern China and its Implications for Cenozoic Tectonics

    Science.gov (United States)

    Liu, S.; Wang, L.

    2005-12-01

    As one of the super-large scale sedimentary basins in China, the Tarim basin is also the strategic basement for Chinese `Natural gas transportation from west to east' project. To know its thermal regime is vital for understanding the deformation and oil gas resource in Tarim basin. Integrated the abundant data of geotemperature and rock thermophysical parameters collected and measured in the basin with corresponding geothermal modeling, here we present the characteristics of geotemperature field, thermal evolution and lithospheric thermo-rheological structure of the Tarim basin, along with the implications for formation and deformation of basin and hydrocarbon reservoir. Our results show that the average present-day heat flow of the basin is about 45 mW/m2 and 18-20°/km for geotemperature gradient, respectively. The basin is characterized by lower temperature in a whole. Lateral heterogeneities exist for the distribution of geotemperature field in the basin. The structural units of basin differ much in the geothermal features; generally, the depression areas are of relatively low geotemperature while high for those uplifts and highs in the basin. Thermal evolution modeling of the basin indicated that it has experienced four different phases since basin formation as follows: high heat flow phase from Sinian to Ordovician, thermal attenuation phase during Silurian to late Paleozoic, then stable thermal evolution phase in Mesozoic, and flexural deformation of lithosphere in Cenozoic. The thickness of the thermal lithosphere of basin is 168-192 km, and 25-28km for the crustal brittle-ductile transition depth; the total lithospheric strength is 1.6-7.8*10**13 N/m. The lithosphere beneath basin is characterized by the rigid block with low temperature but large strength, and deform in a whole. Responded to the far field effect of the Cenozoic India-Eurasia collision, the lithosphere beneath Tarim basin is characterized by flexure deformation, resulting in the intensive

  9. The Timan-Pechora Basin province of northwest Arctic Russia; Domanik, Paleozoic total petroleum system

    Science.gov (United States)

    Lindquist, Sandra J.

    1999-01-01

    The Domanik-Paleozoic oil-prone total petroleum system covers most of the Timan-Pechora Basin Province of northwestern Arctic Russia. It contains nearly 20 BBOE ultimate recoverable reserves (66% oil). West of the province is the early Precambrian Eastern European craton margin. The province itself was the site of periodic Paleozoic tectonic events, culminating with the Hercynian Uralian orogeny along its eastern border. The stratigraphic record is dominated by Paleozoic platform and shelf-edge carbonates succeeded by Upper Permian to Triassic molasse siliciclastics that are locally present in depressions. Upper Devonian (Frasnian), deep marine shale and limestone source rocks ? with typically 5 wt % total organic carbon ? by middle Mesozoic time had generated hydrocarbons that migrated into reservoirs ranging in age from Ordovician to Triassic but most focused in Devonian and Permian rocks. Carboniferous structural inversions of old aulacogen borders, and Hercynian (Permian) to Early Cimmerian (Late Triassic to Early Jurassic) orogenic compression not only impacted depositional patterns, but also created and subsequently modified numerous structural traps within the province.

  10. Late Mesozoic basin and range tectonics and related magmatism in Southeast China

    Directory of Open Access Journals (Sweden)

    Dezi Wang

    2012-03-01

    Full Text Available During the Late Mesozoic Middle Jurassic–Late Cretaceous, basin and range tectonics and associated magmatism representative of an extensional tectonic setting was widespread in southeastern China as a result of Pacific Plate subduction. Basin tectonics consists of post-orogenic (Type I and intra-continental extensional basins (Type II. Type I basins developed in the piedmont and intraland during the Late Triassic to Early Jurassic, in which coarse-grained terrestrial clastic sediments were deposited. Type II basins formed during intra-continental crustal thinning and were characterized by the development of grabens and half-grabens. Graben basins were mainly generated during the Middle Jurassic and were associated with bimodal volcanism. Sediments in half-grabens are intercalated with rhyolitic tuffs and lavas and are Early Cretaceous in age with a dominance of Late Cretaceous–Paleogene red beds. Ranges are composed of granitoids and bimodal volcanic rocks, A-type granites and dome-type metamorphic core complexes. The authors analyzed lithological, geochemical and geochronological features of the Late Mesozoic igneous rock assemblages and proposed some geodynamical constraints on forming the basin and range tectonics of South China. A comparison of the similarities and differences of basin and range tectonics between the eastern and western shores of the Pacific is made, and the geodynamical evolution model of the Southeast China Block during Late Mesozoic is discussed. Studied results suggest that the basin and range terrane within South China developed on a pre-Mesozoic folded belt was derived from a polyphase tectonic evolution mainly constrained by subduction of the western Pacific Plate since the Late Mesozoic, leading to formation of various magmatism in a back-arc extensional setting. Its geodynamic mechanism can compare with that of basin and range tectonics in the eastern shore of the Pacific. Differences of basin and range

  11. Structural characteristics of pre-Cenozoic erathem on continental margins of the Southwest Sub-basin, South China Sea and its geological implications

    Science.gov (United States)

    Zhu, Rongwei; Liu, Hailing; Yan, Pin; Yao, Yongjian; Zhou, Yang; Wang, Yin; Li, Yuhan

    2017-04-01

    Pre-Cenozoic structural characteristics on the conjugated continental margins, Zhongsha- Xisha block (ZSXSB) in the northwest and Nansha block (NSB) in the southeast, of the Southwest Sub-basin is fundamental to understand their tectonic contact relationship before the formation of the South China Sea. Some unpublished and published multi-channel seismic profiles together with published drillings and dredge data were correlated for interpretation. The strata of the study region can be divided into the upper, middle and lower structural layers. The upper and middle structural layers with extensional tectonics are Cenozoic, while the lower structural layer suffering compression is Mesozoic-Paleozoic in ZSXSB and Mesozoic in NSB, respectively. These compressional structures were formed mainly in Late Mesozoic Era. Further structural restoration was done to remove the Cenozoic tectonic influence and to calculate the pre-Cenozoic tectonic compression ratios. It is shown that tectonic compression ratios of NNW or NWW orientations gradually increase from the south to the north in the ZSXSB and southern NSB. While tectonic compression ratios of SSE orientations southward gradually decrease in the northern NSB. The variations of the compression ratios may be related to a spreading of the proto-South China Sea in late Jurassic to Early Cretaceous (then located in south of the NSB), which probably had pushed the NSB drifted northward and led to a soft collision suture between the ZSXSB and NSB. Thus the spreading of the Southwest Sub-basin may have started along suture zone pre-existed between the ZSXSB and NSB, which is tectonically weakness zone. Key words: Southwest Sub-basin of the South China Sea, conjugated continental margins, pre-Cenozoic compressive deformation structure, structural restoration, soft collision suture, proto-South China Sea Key words: Southwest Sub-basin of the South China Sea, Conjugated continental margins, Pre-Cenozoic structure, Structural

  12. Transcending an Urban-Rural Divide: Rural Youth's Resistance to Townization and Schooling, a Case Study of a Middle School in Northwest China

    Science.gov (United States)

    Lou, Jingjing

    2011-01-01

    Based on an ethnographic study in a rural middle school in Northwest China, the author explores how the transition of the rural countryside, specifically townization, has challenged the urban-rural dichotomy being reproduced in and by formal schooling. Rural students express criticism of the chaos, pollution, and corruption they have experienced…

  13. Biomass Carbon Sequestration Potential by Riparian Forest in the Tarim River Watershed, Northwest China: Implication for the Mitigation of Climate Change Impact

    Directory of Open Access Journals (Sweden)

    Tayierjiang Aishan

    2018-04-01

    Full Text Available Carbon management in forests has become the most important agenda of the first half of the 21st century in China in the context of the mitigation of climate change impact. As the main producer of the inland river basin ecosystem in arid region of Northwest China, the desert riparian forest maintains the regional environment and also holds a great significance in regulating the regional/global carbon cycle. In this study, we estimated the total biomass, carbon storage, as well as monetary ecosystem service values of desert riparian Populus euphratica Oliv. in the lower reaches of the Tarim River based on terrestrial forest inventory data within an area of 100 ha (100 plots with sizes of 100 m × 100 m and digitized tree data within 1000 ha (with 10 m × 10 m grid using a statistical model of biomass estimation against tree height (TH and diameter at breast height (DBH data. Our results show that total estimated biomass and carbon storage of P. euphratica within the investigated area ranged from 3.00 to 4317.00 kg/ha and from 1.82 to 2158.73 kg/ha, respectively. There was a significant negative relationship (p < 0.001 between biomass productivity of these forests and distance to the river and groundwater level. Large proportions of biomass (64% of total biomass are estimated within 200 m distance to the river where groundwater is relatively favorable for vegetation growth and biomass production. However, our data demonstrated that total biomass showed a sharp decreasing trend with increasing distance to the river; above 800 m distance, less biomass and carbon storage were estimated. The total monetary value of the ecosystem service “carbon storage” provided by P. euphratica was estimated to be $6.8 × 104 USD within the investigated area, while the average monetary value was approximately $70 USD per ha, suggesting that the riparian forest ecosystem in the Tarim River Basin should be considered a relevant regional carbon sink. The findings of

  14. Assessment of undiscovered continuous oil and gas resources in the Bohaiwan Basin Province, China, 2017

    Science.gov (United States)

    Schenk, Christopher J.; Tennyson, Marilyn E.; Mercier, Tracey J.; Woodall, Cheryl A.; Finn, Thomas M.; Brownfield, Michael E.; Le, Phuong A.; Klett, Timothy R.; Gaswirth, Stephanie B.; Marra, Kristen R.; Leathers-Miller, Heidi M.; Potter, Christopher J.

    2018-02-07

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered, technically recoverable continuous resources of 2.0 billion barrels of oil and 20.3 trillion cubic feet of gas in the Bohaiwan Basin Province, China.

  15. The role of social capital for farmers’ climate change adaptation in Lancang River basin in China

    NARCIS (Netherlands)

    Gong, Y.; Li, Hao; Parks, Moon; Fraiture, de C.M.S.

    2017-01-01

    This paper distinguishes between bridging and bonding social capital to assess their roles for individual farmers’ adaptation strategies taken through technology adoption. Based on primary data collected in Langcang River (LCR) basin area in southwestern China, the paper finds: (1) adaptation

  16. Assessment of Permian tight oil and gas resources in the Junggar basin of China, 2016

    Science.gov (United States)

    Potter, Christopher J.; Schenk, Christopher J.; Tennyson, Marilyn E.; Klett, Timothy R.; Gaswirth, Stephanie B.; Leathers-Miller, Heidi M.; Finn, Thomas M.; Brownfield, Michael E.; Pitman, Janet K.; Mercier, Tracey J.; Le, Phuong A.; Drake, Ronald M.

    2017-04-05

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 764 million barrels of oil and 3.5 trillion cubic feet of gas in tight reservoirs in the Permian Lucaogou Formation in the Junggar basin of northwestern China.

  17. Technical status and challenges of shale gas development in Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Pingli Liu

    2015-03-01

    This paper begins with the introduction of shale gas reserve distribution in China and the identified shale gas formation in Sichuan Basin. The following paper reviews the methodology employed in the geophysical prospecting, drilling and completion, and hydraulic fracturing process. Since China is in the early stage of shale gas development, there is a great technical gap between China and North America. Based on literature review, the major challenges faced in the exploration and production process are identified. What presented in this paper should be of particular interest to the personnels involved in shale gas production in China and countries that are about to set foot in shale gas business. It will also be of interest to researchers who are dedicated to developing these technologies to unlock unconventional gas resources in China.

  18. [Health assessment of river ecosystem in Haihe River Basin, China].

    Science.gov (United States)

    Hao, Li-Xia; Sun, Ran-Hao; Chen, Li-Ding

    2014-10-01

    With the development of economy, the health of river ecosystem is severely threatened because of the increasing effects of human activities on river ecosystem. In this paper, the authors assessed the river ecosystem health in aspects of chemical integrity and biological integrity, using the criterion in water quality, nutrient, and benthic macroinvertebrates of 73 samples in Haihe River Basin. The research showed that the health condition of river ecosystem in Haihe River Basin was bad overall since the health situation of 72. 6% of the samples was "extremely bad". At the same time, the health situation in Haihe River Basin exhibited obvious regional gathering effect. We also found that the river water quality was closely related to human activities, and the eutrophication trend of water body was evident in Haihe River Basin. The biodiversity of the benthic animal was low and lack of clean species in the basin. The indicators such as ammonia nitrogen, total nitrogen and total phosphorus were the key factors that affected the river ecosystem health in Haihe River Basin, so the government should start to curb the deterioration of river ecosystem health by controlling these nutrients indicators. For river ecosystem health assessment, the multi-factors comprehensive evaluation method was superior to single-factor method.

  19. Evaluation of the tourism climate in the Hexi Corridor of northwest China's Gansu Province during 1980-2012

    Science.gov (United States)

    Zhang, Fuxian; Zhang, Mingjun; Wang, Shengjie; Qiang, Fang; Che, Yanjun; Wang, Jie

    2017-08-01

    As a pivotal section of the Silk Road in northwest China, the Hexi Corridor is a popular tourist destination. In this study, the tourism climate conditions in this region were discussed using the Physiologically Equivalent Temperature (PET) and the Climate-Tourism/Transfer-information-Scheme (CTIS) from 1980 to 2012. Overall, cold or cool stress was prevalent in the area, and the optimal travel period was from May to September. With global warming, the annual numbers of cumulative days with relatively cold conditions decreased, and the annual numbers of cumulative days with comfortable and relatively hot conditions increased. Two typical stations, Wushaoling and Dunhuang, were compared and analysed for their tourism climate information according to the frequency of PET and CTIS conditions, respectively. In addition, regional variations in the tourism climate conditions based on geographic information systems (GIS) were investigated during the optimal travel period.

  20. Allele frequencies of 18 autosomal STR loci in the Uyghur population living in Kashgar Prefecture, Northwest China.

    Science.gov (United States)

    Zhang, Jian; Li, Zhenghui; Mo, Xiaoting; Ma, Wenhua; Zhang, Hantao; Lin, Ziqing; Ye, Jian

    2018-03-10

    There is currently no large population data-based data set in Kashgar Prefecture Uyghur. The allele frequencies of 18 autosomal short tandem repeat (STR) loci included in the DNATyper™ 19 kit were evaluated in 2600 Uyghur individuals living in Kashgar Prefecture, Northwest China. The values of combined power of discrimination (CPD) and combined probability of exclusion (CPE) of all 18 autosomal STR loci were 0.99999999999999999998235 and 0.99999998670, respectively. Phylogenetic analyses revealed that the Uyghur population has a closer relationship with the Xinjiang-Kazakh, Inner Mongolia-Mongolian, and other three Uyghur populations. In addition, our results are consistent with the hypothesis that Uyghur population is an admixture of Eastern Asian and European populations.

  1. Age structure and growth of degraded Populus euphratica floodplain forests in north-west China and perspectives for their recovery.

    Science.gov (United States)

    Westermann, Janneke; Zerbe, Stefan; Eckstein, Dieter

    2008-05-01

    The Populus euphratica floodplain forests along the lower reaches of the Tarim River in continental-arid Xinjiang (north-west China) have been declining in recent decades as a result of dam constructions and the withdrawal of water from the river. Since 2000, controlled flooding has been carried out to counteract this process of degradation. However, the consequences of a changing water regime for the floodplain ecosystem are not yet sufficiently investigated. In 2004 we sampled a total of 150 P. euphratica trees along two transects at the middle and lower reaches of the Tarim River to compare the age structure and growth of these two tree populations. The anthropogenic drawdown of the groundwater table had no effect on the average growth of the trees at the lower reaches. However, tree growth abruptly increased after controlled flooding, thus showing distinct signs of recovery.

  2. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

    Directory of Open Access Journals (Sweden)

    Xin Liu

    Full Text Available Modelling crop evapotranspiration (ET response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1 and summer maize (scenario 2 by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

  3. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

    Science.gov (United States)

    Liu, Xin; Wang, Sufen; Xue, Han; Singh, Vijay P

    2015-01-01

    Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

  4. A toxic endophyte-infected grass helps reverse degradation and loss of biodiversity of over-grazed grasslands in northwest China.

    Science.gov (United States)

    Yao, Xiang; Christensen, Michael J; Bao, Gensheng; Zhang, Chunping; Li, Xiuzhang; Li, Chunjie; Nan, Zhibiao

    2015-12-18

    Overgrazing of China's grasslands is increasingly causing biodiversity to decline. In degenerated grasslands of northwest China endophyte (Epichloё gansuensis) infected Achnatherum inebrians (drunken horse grass) is becoming widely distributed because of its toxicity to livestock. In this study, we investigated the ecological consequences of endophyte toxicity in this native grass, at three sites in northwest China, by comparing seed production of plant species and arthropod abundance in overgrazed grasslands with and without the presence of A. inebrians. Our findings demonstrate that the presence of endophyte infected A. inebrians reduces the loss of plant and arthropod biodiversity by providing a protected nursery free of animal grazing. Therefore, A. inebrians, typically regarded as an unwanted toxic invader by pastoralists, should be viewed as beneficial for grasslands as its presence maintains plant and arthropod biodiversity, and provides a foundation stone in the reconstruction and restoration of these grassland ecosystems.

  5. Analysis and prediction of reference evapotranspiration with climate change in Xiangjiang River Basin, China

    Directory of Open Access Journals (Sweden)

    Xin-e Tao

    2015-10-01

    Full Text Available Reference evapotranspiration (ET0 is often used to estimate actual evapotranspiration in water balance studies. In this study, the present and future spatial distributions and temporal trends of ET0 in the Xiangjiang River Basin (XJRB in China were analyzed. ET0 during the period from 1961 to 2010 was calculated with historical meteorological data using the FAO Penman-Monteith (FAO P-M method, while ET0 during the period from 2011 to 2100 was downscaled from the Coupled Model Intercomparison Project Phase 5 (CMIP5 outputs under two emission scenarios, representative concentration pathway 4.5 and representative concentration pathway 8.5 (RCP45 and RCP85, using the statistical downscaling model (SDSM. The spatial distribution and temporal trend of ET0 were interpreted with the inverse distance weighted (IDW method and Mann-Kendall test method, respectively. Results show that: (1 the mean annual ET0 of the XJRB is 1 006.3 mm during the period from 1961 to 2010, and the lowest and highest values are found in the northeast and northwest parts due to the high latitude and spatial distribution of climatic factors, respectively; (2 the SDSM performs well in simulating the present ET0 and can be used to predict the future ET0 in the XJRB; and (3 CMIP5 predicts upward trends in annual ET0 under the RCP45 and RCP85 scenarios during the period from 2011 to 2100. Compared with the reference period (1961–1990, ET0 increases by 9.8%, 12.6%, and 15.6% under the RCP45 scenario and 10.2%, 19.1%, and 27.3% under the RCP85 scenario during the periods from 2011 to 2040, from 2041 to 2070, and from 2071 to 2100, respectively. The predicted increasing ET0 under the RCP85 scenario is greater than that under the RCP45 scenario during the period from 2011 to 2100.

  6. Mesozoic basins and associated palaeogeographic evolution in North China

    Directory of Open Access Journals (Sweden)

    Yong-Qing Liu

    2015-04-01

    Besides, during the Late Mesozoic, a huge terrestrial biota, mainly dinosaur fauna, dominated in North China. The Yanliao biota of the Middle–Late Jurassic and the Jehol biota of the Early Cretaceous are characterized by feathered dinosaurs, primitive birds, mammals, pterosaur, insects and plants (angiosperms. In northeastern Asia, this Late Mesozoic tectonic background , palaeogeoraphy and palaeoecology were shared by East China, Korean Peninsula, Japan and the Far East of Russia.

  7. Characteristics of air pollution in different zones of Sichuan Basin, China.

    Science.gov (United States)

    Ning, Guicai; Wang, Shigong; Ma, Minjin; Ni, Changjian; Shang, Ziwei; Wang, Jiaxin; Li, Jingxin

    2018-01-15

    Sichuan Basin, located in southwest China, has been ranked as the fourth of heavily air polluted regions in China partly due to its deep mountain-basin topography. However, spatial-temporal distribution of air pollution over the basin is still unclear due to the lack of monitoring data and poor knowledge. Since January 2015, six criteria air pollutants began to be monitored in 20 cities across the basin. The measured data enable us to analyze the basin-wide spatial-temporal distribution characteristics of these air pollutants. Results revealed heavy air pollution in the bottom zone, medium in the slope zone, and light pollution in the edge zone of the Basin in terms of the altitudes of air quality monitoring stations across the Basin. The average concentrations of PM 2.5 and PM 10 were 55.87μg/m 3 and 86.49μg/m 3 in the bottom, 33.76μg/m 3 and 63.33μg/m 3 in the slope, and 19.71μg/m 3 and 35.06μg/m 3 in the edge, respectively. In the bottom and slope of the basin, high PM 2.5 concentration events occurred most frequently in winter . While in summer, ozone became primary pollutant. Among the six air pollutants, concentrations of PM 2.5 and PM 10 decrease dramatically with increasing altitude which was fitted by a nonlinear relationship between particulate matter (PM) concentrations and altitude. This relationship was validated by extinction coefficient profiles from CALIPSO observations and EV-lidar data, and hence used to reflect vertical distribution of air PM concentrations. It has been found that the thickness of higher PM concentrations is less than 500m in the basin. In the bottom of the basin, PM concentrations exhibited stronger horizontal homogeneities as compared with those in the North China Plain and Yangtze River Delta. However, gaseous pollutants seemed not to show clear relationships between their concentrations and altitudes in the basin. Their horizontal homogeneities were less significant compared to PM. Copyright © 2017 Elsevier B.V. All

  8. Adaptive Fusion of Information for Seeing into Ordos Basin, China: A China-Germany-US Joint Venture.

    Science.gov (United States)

    Yeh, T. C. J.; Yin, L.; Sauter, M.; Hu, R.; Ptak, T.; Hou, G. C.

    2014-12-01

    Adaptive fusion of information for seeing into geological basins is the theme of this joint venture. The objective of this venture is to initiate possible collaborations between scientists from China, Germany, and US to develop innovative technologies, which can be utilized to characterize geological and hydrological structures and processes as well as other natural resources in regional scale geological basins of hundreds of thousands of kilometers (i.e., the Ordos Basin, China). This adaptive fusion of information aims to assimilate active (manmade) and passive (natural) hydrologic and geophysical tomography surveys to enhance our ability of seeing into hydrogeological basins at the resolutions of our interests. The active hydrogeophysical tomography refers to recently developed hydraulic tomgoraphic surveys by Chinese and German scientists, as well as well-established geophysical tomography surveys (such as electrical resistivity tomography, cross-borehole radars, electrical magnetic surveys). These active hydrogeophysical tomgoraphic surveys have been proven to be useful high-resolution surveys for geological media of tens and hundreds of meters wide and deep. For basin-scale (i.e., tens and hundreds of kilometers) problems, their applicabilities are however rather limited. The passive hydrogeophysical tomography refers to unexplored technologies that exploit natural stimuli as energy sources for tomographic surveys, which include direct lightning strikes, groundwater level fluctuations due to earthquakes, river stage fluctuations, precipitation storms, barometric pressure variations, and long term climate changes. These natural stimuli are spatially varying, recurrent, and powerful, influencing geological media over great distances and depths (e.g., tens and hundreds of kilometers). Monitoring hydrological and geophysical responses of geological media to these stimuli at different locations is tantamount to collecting data of naturally occurring tomographic

  9. Detecting runoff variation in Weihe River basin, China

    Science.gov (United States)

    Jingjing, F.; Qiang, H.; Shen, C.; Aijun, G.

    2015-05-01

    Dramatic changes in hydrological factors in the Weihe River basin are analysed. These changes have exacerbated ecological problems and caused severe water shortages for agriculture, industries and the human population in the region, but their drivers are uncertain. The Mann-Kendall test, accumulated departure analysis, sequential clustering and the sliding t-test methods were used to identify the causes of changes in precipitation and runoff in the Weihe basin. Change-points were identified in the precipitation and runoff records for all sub-catchments. For runoff, the change in trend was most pronounced during the 1990s, whereas changes in precipitation were more prominent earlier. The results indicate that human activities have had a greater impact than climate change on the hydrology of the Weihe basin. These findings have significant implications for the establishment of effective strategies to counter adverse effects of hydrological changes in the catchment.

  10. Detecting runoff variation in Weihe River basin, China

    Directory of Open Access Journals (Sweden)

    F. Jingjing

    2015-05-01

    Full Text Available Dramatic changes in hydrological factors in the Weihe River basin are analysed. These changes have exacerbated ecological problems and caused severe water shortages for agriculture, industries and the human population in the region, but their drivers are uncertain. The Mann-Kendall test, accumulated departure analysis, sequential clustering and the sliding t-test methods were used to identify the causes of changes in precipitation and runoff in the Weihe basin. Change-points were identified in the precipitation and runoff records for all sub-catchments. For runoff, the change in trend was most pronounced during the 1990s, whereas changes in precipitation were more prominent earlier. The results indicate that human activities have had a greater impact than climate change on the hydrology of the Weihe basin. These findings have significant implications for the establishment of effective strategies to counter adverse effects of hydrological changes in the catchment.

  11. Hypothetical Source Crater for Australasian Tektites: Moving from Indochina to Northwest China?

    Science.gov (United States)

    Mizera, J.; Řanda, Z.; Kameník, J.; Klokočník, J.; Kostelecký, J.

    2016-08-01

    We argue against the generally accepted hypothetical location of the unknown source crater for Australasian tektites to Indochina, and present a hypothesis of a possible location of the AAT source crater in deserts of NW China.

  12. Investigating the evolutionary history of irrigated agricultural technology in the Heihe River Basin, China

    Science.gov (United States)

    Wu, S.; Wei, Y.; Zhao, Y.; Zheng, H.

    2017-12-01

    Human's innovative abilities do not only enable rapid expansion of civilization, but also lead to enormous modifications on the natural environment. Technology, while a key factor embedded in socioeconomic developments, its impacts have been rarely appropriately considered in river basin management. This research aims to examine the evolutionary history of irrigated agricultural technology in the Heihe River Basin, China, and how its characteristics interacted with the river basin environment. It adopts a content analysis approach to collect and summarize quantitative technological information in the Heihe River Basin across a time span of more than 2000 years from the Han Dynasty (206 BC) to 2015. Two Chinese academic research databases: Wan Fang Data and China National Knowledge Infrastructure (CNKI) were chosen as data sources. The results show that irrigated agricultural technologies in Heihe River Basin have shifted from focusing on developing new farming tools and cultivation methods to adapting modernized, water-saving irrigation methods and water diversion infrastructures. In additions, the center of irrigated agricultural technology in the Heihe river basin has moved from downstream to middle stream since the Ming Dynasty (1368AD) as a result of degraded natural environment. The developing trend of technology in the Heihe River Basin thus coincides with the change of societal focus from agricultural production efficiency to the human-water balance and environmental remediation. This research demonstrates that irrigated agricultural technologies had a twisted evolutionary history in the Heihe River Basin, influenced by a diverse range of environmental and socioeconomic factors. It provides insights into the fact that technology exhibits a co-evolutionary characteristic with the social development history in the region, pointing towards the urgent need to maintain the balance between human and environment.

  13. Aerodynamic roughness length estimation from very high-resolution imaging LIDAR observations over the Heihe basin in China

    Directory of Open Access Journals (Sweden)

    J. Colin

    2010-12-01

    Full Text Available Roughness length of land surfaces is an essential variable for the parameterisation of momentum and heat exchanges. The growing interest in the estimation of the surface turbulent flux parameterisation from passive remote sensing leads to an increasing development of models, and the common use of simple semi-empirical formulations to estimate surface roughness. Over complex surface land cover, these approaches would benefit from the combined use of passive remote sensing and land surface structure measurements from Light Detection And Ranging (LIDAR techniques. Following early studies based on LIDAR profile data, this paper explores the use of imaging LIDAR measurements for the estimation of the aerodynamic roughness length over a heterogeneous landscape of the Heihe river basin, a typical inland river basin in the northwest of China. The point cloud obtained from multiple flight passes over an irrigated farmland area were used to separate the land surface topography and the vegetation canopy into a Digital Elevation Model (DEM and a Digital Surface Model (DSM respectively. These two models were then incorporated in two approaches: (i a strictly geometrical approach based on the calculation of the plan surface density and the frontal surface density to derive a geometrical surface roughness; (ii a more aerodynamic approach where both the DEM and DSM are introduced in a Computational Fluid Dynamics model (CFD. The inversion of the resulting 3-D wind field leads to a fine representation of the aerodynamic surface roughness. Examples of the use of these three approaches are presented for various wind directions together with a cross-comparison of results on heterogeneous land cover and complex roughness element structures.

  14. Expansion of the South China Sea basin: Constraints from magnetic anomaly stripes, sea floor topography, satellite gravity and submarine geothermics

    Directory of Open Access Journals (Sweden)

    Xuezhong Yu

    2017-01-01

    Full Text Available The widely distributed E–W-trending magnetic anomaly stripes in the central basin and the N–E-trending magnetic anomaly stripes in the southwest sub-basin provide the most important evidence for Neogene expansion of the South China Sea. The expansion mechanism remains, however, controversial because of the lack of direct drilling data, non-systematic marine magnetic survey data, and irregular magnetic anomaly stripes with two obvious directions. For example, researchers have inferred different ages and episodes of expansion for the central basin and southwest sub-basin. Major controversy centers on the order of basinal expansion and the mechanism of expansion for the entire South China Sea basin. This study attempts to constrain these problems from a comprehensive analysis of the seafloor topography, magnetic anomaly stripes, regional aeromagnetic data, satellite gravity, and submarine geothermics. The mapped seafloor terrain shows that the central basin is a north-south rectangle that is relatively shallow with many seamounts, whereas the southwest sub-basin is wide in northeast, gradually narrows to the southwest, and is relatively deeper with fewer seamounts. Many magnetic anomaly stripes are present in the central basin with variable dimensions and directions that are dominantly EW-trending, followed by the NE-, NW- and NS-trending. Conversely such stripes are few in the southwest sub-basin and mainly NE-trending. Regional magnetic data suggest that the NW-trending Ailaoshan-Red River fault extends into the South China Sea, links with the central fault zone in the South China Sea, which extends further southward to Reed Tablemount. Satellite gravity data show that both the central basin and southwest sub-basin are composed of oceanic crust. The Changlong seamount is particularly visible in the southwest sub-basin and extends eastward to the Zhenbei seamount. Also a low gravity anomaly zone coincides with the central fault zone in the sub-basin

  15. Water risk assessment for river basins in China based on WWF water risk assessment tools

    Directory of Open Access Journals (Sweden)

    N. Wei

    2014-09-01

    Full Text Available Water resource problems, one of the most important environmental and socio-economic issues, have been a common concern worldwide in recent years. Water resource risks are attracting more and more attention from the international community and national governments. Given the current situations of water resources and the water environment, and the characteristics of water resources management and information statistics of China, this paper establishes an index system for water risk assessment in river basins of China based on the index system of water risk assessment proposed by the World Wide Fund For Nature (WWF and German Investment and Development Co., Ltd (DEG. The new system is more suitable for Chinese national conditions and endorses the international assessment index. A variety of factors are considered to determine the critical values of classification for each index, and the indexes are graded by means of 5-grade and 5-score scales; the weights and calculation methods of some indexes are adjusted, with the remaining indexes adopting the method of WWF. The Weighted Comprehensive Index Summation Process is adopted to calculate the integrated assessment score of the river basin. The method is applied to the Haihe River basin in China. The assessment shows that the method can accurately reflect the water risk level of different river basins. Finally, the paper discusses the continuing problems in water risk assessment and points out the research required to provide a reference for further study in this field.

  16. Pollution of intensively managed greenhouse soils by nutrients and heavy metals in the Yellow River Irrigation Region, Northwest China.

    Science.gov (United States)

    Kong, Xiaole; Cao, Jing; Tang, Rangyun; Zhang, Shengqiang; Dong, Fang

    2014-11-01

    The present study aimed to assess the potential ecological risk of heavy metals and nutrient accumulation in polytunnel greenhouse soils in the Yellow River irrigation region (YRIR), Northwest China, and to identify the potential sources of these heavy metals using principal component analysis. Contents of available nitrogen (AN), phosphorus (AP), and potassium (AK) in the surface polytunnel greenhouse soils (0-20 cm) varied from 13.42 to 486.78, from 39.10 to 566.97, and from 21.64 to 1,156.40 mg kg(-1), respectively, as well as AP, soil organic matter (SOM) and AK contents tended to increase significantly at the 0-20- and 20-40-cm soil layers. Heavy metal accumulations occurred in the polytunnel greenhouse soils as compared to arable soils, especially at a depth of 20 cm where Cd, Zn and Cu contents were significantly higher than arable soil. Cd and As were found to be the two main polluting elements in the greenhouse soils because their contents exceeded the thresholds established for greenhouse vegetable production HJ333-2006 in China and the background of Gansu province. It has been shown that Cd, Cu, Pb and Zn at the 0-20-cm soil layer were derived mainly from agricultural production activities, whereas contents of Cr and Ni at the same soil layer were determined by 'natural' factors and As originated from natural sources, deposition and irrigation water.

  17. Genomic analyses of metal resistance genes in three plant growth promoting bacteria of legume plants in Northwest mine tailings, China.

    Science.gov (United States)

    Xie, Pin; Hao, Xiuli; Herzberg, Martin; Luo, Yantao; Nies, Dietrich H; Wei, Gehong

    2015-01-01

    To better understand the diversity of metal resistance genetic determinant from microbes that survived at metal tailings in northwest of China, a highly elevated level of heavy metal containing region, genomic analyses was conducted using genome sequence of three native metal-resistant plant growth promoting bacteria (PGPB). It shows that: Mesorhizobium amorphae CCNWGS0123 contains metal transporters from P-type ATPase, CDF (Cation Diffusion Facilitator), HupE/UreJ and CHR (chromate ion transporter) family involved in copper, zinc, nickel as well as chromate resistance and homeostasis. Meanwhile, the putative CopA/CueO system is expected to mediate copper resistance in Sinorhizobium meliloti CCNWSX0020 while ZntA transporter, assisted with putative CzcD, determines zinc tolerance in Agrobacterium tumefaciens CCNWGS0286. The greenhouse experiment provides the consistent evidence of the plant growth promoting effects of these microbes on their hosts by nitrogen fixation and/or indoleacetic acid (IAA) secretion, indicating a potential in-site phytoremediation usage in the mining tailing regions of China. Copyright © 2014. Published by Elsevier B.V.

  18. Earth fissures in Qinglong Graben in Yuncheng Basin, China

    Indian Academy of Sciences (India)

    72

    factors in the development and expansion of the earth fissures in Qinglong Graben. 20. The earth fissures forming ... Keywords: Earth fissure, Qinglong Graben, Yuncheng Basin, syn-sedimentary. 26 fault, forming process. 27. 1. ...... double spring flat earthquake, West-Central Nevada. Seismol Soc Am Bull 93(6):. 367.

  19. Current strain accumulation in the hinterland of the northwest Himalaya constrained by landscape analyses, basin-wide denudation rates, and low temperature thermochronology

    Science.gov (United States)

    Morell, Kristin D.; Sandiford, Mike; Kohn, Barry; Codilean, Alexandru; Fülöp, Réka-H.; Ahmad, Talat

    2017-11-01

    Rupture associated with the 25 April 2015 Mw 7.8 Gorkha (Nepal) earthquake highlighted our incomplete understanding of the structural architecture and seismic cycle processes that lead to Himalayan mountain building in Central Nepal. In this paper we investigate the style and kinematics of active mountain building in the Himalayan hinterland of Northwest India, approximately 400 km to the west of the hypocenter of the Nepal earthquake, via a combination of landscape metrics and long- (Ma) and short-term (ka) erosion rate estimates (from low temperature thermochronometry and basin-wide denudation rate estimates from 10Be concentrations). We focus our analysis on the area straddling the PT2, the physiographic transition between the Lesser and High Himalaya that has yielded important insights into the nature of hinterland deformation across much of the Himalaya. Our results from Northwest India reveal a distinctive PT2 that separates a Lesser Himalaya region with moderate relief (∼1000 m) and relatively slow erosion (400 km distance between them, similar spatiotemporal patterns of erosion and deformation observed in Northwest India and Central Nepal suggest both regions experience similar styles of active strain accumulation and both are susceptible to large seismic events.

  20. Recent ground fissures in the Hetao basin, Inner Mongolia, China

    Science.gov (United States)

    He, Zhongtai; Ma, Baoqi; Long, Jianyu; Zhang, Hao; Liang, Kuan; Jiang, Dawei

    2017-10-01

    Ground fissures are a geological hazard with complex formation mechanisms. Increasing amounts of human activity have created more ground fissures, which can destroy buildings and threaten human security. Some ground fissures indicate potentially devastating earthquakes, so we must pay attention to these hazards. This paper documents recently discovered ground fissures in the Hetao basin. These ground fissures are located along the frontal margins of the terraces of the Sertengshan piedmont fault. These fissures are 600-1600 m long, 5-50 cm wide, and at most 1 m deep. These ground fissures emerged after 2010 and ruptured newly constructed roads and field ridges. The deep geodynamic mechanisms within this extensional environment, which is dominated by NE-SW principal compressive shear, involve N-S tensile stress, which has produced continuous subsidence in the Hetao basin and continuous activity along the Sertengshan piedmont fault since the late Quaternary. Trenches across the ground fissures reveal that the fissures are the latest manifestation of the activity of preexisting faults and are the result of creep-slip movement along the faults. The groundwater level in the Hetao basin has been dropping since the 1960s because of overexploitation, resulting in subsidence. When the tensile stress exceeds the ultimate tensile strength of the strata, the strata rupture along preexisting faults, producing ground fissures. Thus, the Sertengshan piedmont fault planes are the structural foundation of the ground fissures, and groundwater extraction induces the development of ground fissures.

  1. Mid-Pleistocene Acheulean-like stone technology of the Bose basin, South China.

    Science.gov (United States)

    Yamei, H; Potts, R; Baoyin, Y; Zhengtang, G; Deino, A; Wei, W; Clark, J; Guangmao, X; Weiwen, H

    2000-03-03

    Stone artifacts from the Bose basin, South China, are associated with tektites dated to 803,000 +/- 3000 years ago and represent the oldest known large cutting tools (LCTs) in East Asia. Bose toolmaking is compatible with Mode 2 (Acheulean) technologies in Africa in its targeted manufacture and biased spatial distribution of LCTs, large-scale flaking, and high flake scar counts. Acheulean-like tools in the mid-Pleistocene of South China imply that Mode 2 technical advances were manifested in East Asia contemporaneously with handaxe technology in Africa and western Eurasia. Bose lithic technology is associated with a tektite airfall and forest burning.

  2. Analysis of the evolution of precipitation in the Haihe river basin of China under changing environment

    Science.gov (United States)

    Ding, Xiangyi; Liu, Jiahong; Gong, Jiaguo

    2018-02-01

    Precipitation is one of the important factors of water cycle and main sources of regional water resources. It is of great significance to analyze the evolution of precipitation under changing environment for identifying the evolution law of water resources, thus can provide a scientific reference for the sustainable utilization of water resources and the formulation of related policies and measures. Generally, analysis of the evolution of precipitation consists of three levels: analysis the observed precipitation change based on measured data, explore the possible factors responsible for the precipitation change, and estimate the change trend of precipitation under changing environment. As the political and cultural centre of China, the climatic conditions in the Haihe river basin have greatly changed in recent decades. This study analyses the evolution of precipitation in the basin under changing environment based on observed meteorological data, GCMs and statistical methods. Firstly, based on the observed precipitation data during 1961-2000 at 26 meteorological stations in the basin, the actual precipitation change in the basin is analyzed. Secondly, the observed precipitation change in the basin is attributed using the fingerprint-based attribution method, and the causes of the observed precipitation change is identified. Finally, the change trend of precipitation in the basin under climate change in the future is predicted based on GCMs and a statistical downscaling model. The results indicate that: 1) during 1961-2000, the precipitation in the basin showed a decreasing trend, and the possible mutation time was 1965; 2) natural variability may be the factor responsible for the observed precipitation change in the basin; 3) under climate change in the future, precipitation in the basin will slightly increase by 4.8% comparing with the average, and the extremes will not vary significantly.

  3. Dust deposition and ambient PM10 concentration in northwest China: Spatial and temporal variability

    Science.gov (United States)

    Aeolian dust transport and deposition are important geophysical processes which influence global bio-geochemical cycles. Currently, reliable continental deposition data are scarce in central Asia. Located in the eastern part of central Asia, Xinjiang Province of northwestern China has long played a ...

  4. A decade of change in breastfeeding in China's far north-west

    Directory of Open Access Journals (Sweden)

    Xiao Cuiqin

    2006-11-01

    Full Text Available Abstract Background There have been considerable changes in breastfeeding practices in China over the past forty years. However China is a very large country, and breastfeeding rates in different parts of China vary considerably. The objective of this paper is to identify and compare breastfeeding types and rates between 1994–1996 and 2003–2004 in Shihezi, Xinjiang Uygur Autonomous Region, PR China. Methods In 1994–1996, a study of breastfeeding (n = 2197 was undertaken in Shihezi, Xinjiang, PR China. A decade later in 2003–2004, a longitudinal study (n = 545 of infant feeding practices was undertaken in the same area. Results The 'any breastfeeding' rates at 1, 4 and 6 months were 94%, 82% and 78% respectively in the early 1990s. A decade later, breastfeeding at 1 month was lower, but rates at 4 and 6 months remained the same. In 2004 the 'full breastfeeding' rate at one month was significantly higher (57% than a decade earlier (38%, but after 3 months there was a rapid decline. This reflected a shift in the way complementary foods are introduced: the initial introduction was later, but by a higher proportion of mothers. Conclusion The rate of breastfeeding at one month is significantly lower in 2003–2004 when compared to 1994–1996. The 'full breastfeeding' rates were initially higher, but after 3 months were then lower. The Chinese national breastfeeding targets were not reached in either period of the study. These studies show the need to further promote full or exclusive breastfeeding and further longitudinal studies are necessary to provide the detailed knowledge about risk factors required for health promotion programs.

  5. Impact of climate change and anthropogenic activities on stream flow and sediment discharge in the Wei River basin, China

    NARCIS (Netherlands)

    Gao, P.; Geissen, V.; Ritsema, C.J.; Mu, X.M.; Wang, F.

    2013-01-01

    Reduced stream flow and increased sediment discharge are a major concern in the Yellow River basin of China, which supplies water for agriculture, industry and the growing populations located along the river. Similar concerns exist in the Wei River basin, which is the largest tributary of the Yellow

  6. Mapping and Assessment of Degraded Land in the Heihe River Basin, Arid Northwestern China

    Directory of Open Access Journals (Sweden)

    Yumin Cai

    2007-10-01

    Full Text Available Land degradation is a great threat in the Heihe River Basin, located in the aridinland of northwestern China and land desertification is one of the main aspects ofenvironmental changes in this basin. Previous studies have focused on water resourceutilization and soil erosion, but the status of degraded land in the Heihe River Basin, suchas its distribution, extent and precise characteristics is often inadequately known. Based onfield observations and TM images from the year 2003, this study provides classificationand evaluation information concerning the degraded land in the basin of the Heihe River.There are five types of degraded land types in the Heihe River Basin: water eroded in thesouthern mountains, sandified and vegetation degraded near the oases, aridized in the lowreaches, and salinized in the lowlands. The total degraded area covers 29,355.5 km2,22.58% of the land in the study area. Finally, degraded land in the Heihe River Basin wasevaluated according to changes in the physical structure and chemical components of soils,land productivity, secondary soil salt, and water conditions.

  7. Sustainable management of river oases along the Tarim River (SuMaRiO) in Northwest China under conditions of climate change

    OpenAIRE

    Rumbaur, C.;Thevs, N.;Disse, M.;Ahlheim, M.;Brieden, A.;Cyffka, B.;Duethmann, D.;Feike, T.;Frör, O.;Gärtner, P.;Halik, Ü.;Hill, J.;Hinnenthal, M.;Keilholz, P.;Kleinschmit, B.;Krysanova, V.;Kuba, M.;Mader, S.;Menz, C.;Othmanli, H.;Pelz, S.;Schroeder, M.;Siew, T. F.;Stender, V.;Stahr, K.;Thomas, F. M.;Welp, M.;Wortmann, M.;Zhao, X.;Chen, X.;Jiang, T.;Luo, J.;Yimit, H.;Yu, R.;Zhang, X.;Zhao, C.

    2017-01-01

    The Tarim River basin, located in Xinjiang, NW China, is the largest endorheic river basin in China and one of the largest in all of Central Asia. Due to the extremely arid climate, with an annual precipitation of less than 100 mm, the water supply along the Aksu and Tarim rivers solely depends on river water. This is linked to anthropogenic activities (e.g., agriculture) and natural and semi-natural ecosystems as both compete for water. The ongoing increase in water consumptio...

  8. Odonata diversity of the middle and lower reaches of the Red River basin, Yunnan, China

    Directory of Open Access Journals (Sweden)

    Jin Chen

    2013-09-01

    Full Text Available Eighty six species of Odonata are recorded from the middle and lower reaches of the Red River basin. Archineura hetaerinoides is recorded from China for the first time. Five genera and five species are new to Yunnan Province. Among the six types of odonate habitats, forest streams have the highest species diversity whereas ponds have the most species shared with other habitats. Both of these two habitats are important in biodiversity conservation and need urgent protection.

  9. Evaluation of ecological instream flow considering hydrological alterations in the Yellow River basin, China

    Science.gov (United States)

    Zhang, Qiang; Zhang, Zongjiao; Shi, Peijun; Singh, Vijay P.; Gu, Xihui

    2018-01-01

    The Yellow River is the second largest river in China and is the important source for water supply in the northwestern and northern China. It is often regarded as the mother river of China. Owing to climatic change and intensifying human activities, such as increasing withdrawal of water for meeting growing agricultural irrigation needs since 1986, the flow of Yellow River has decreased, with serious impacts on the ecological environment. Using multiple hydrological indicators and Flow Duration Curve (DFC)-based ecodeficit and ecosurplus, this study investigates the impact of hydrological alterations, such as the impact of water reservoirs or dams, on downstream ecological instream flow. Results indicate that: (1) due to the impoundment and hydrological regulations of water reservoirs, occurrence rates and magnitudes of high flow regimes have decreased and the decrease is also found in the magnitudes of low flow events. These changes tend to be more evident from the upper to the lower Yellow River basin; (2) human activities tend to enhance the instream flow variability, particularly after the 1980s;(3) the ecological environment in different parts of the Yellow River basin is under different degrees of ecological risk. In general, lower to higher ecological risk can be detected due to hydrological alterations from the upper to the lower Yellow River basin. This shows that conservation of ecological environment and river health is facing a serious challenge in the lower Yellow River basin; (4) ecological instream flow indices, such as ecodeficit and ecosurplus, and IHA32 hydrological indicators are in strong relationships, suggesting that ecodeficit and ecosurplus can be regarded as appropriate ecological indicators for developing measures for mitigating the adverse impact of human activities on the conservation of ecological environment in the Yellow River basin.

  10. A Picea crassifolia Tree-Ring Width-Based Temperature Reconstruction for the Mt. Dongda Region, Northwest China, and Its Relationship to Large-Scale Climate Forcing.

    Directory of Open Access Journals (Sweden)

    Yu Liu

    Full Text Available The historical May-October mean temperature since 1831 was reconstructed based on tree-ring width of Qinghai spruce (Picea crassifolia Kom. collected on Mt. Dongda, North of the Hexi Corridor in Northwest China. The regression model explained 46.6% of the variance of the instrumentally observed temperature. The cold periods in the reconstruction were 1831-1889, 1894-1901, 1908-1934 and 1950-1952, and the warm periods were 1890-1893, 1902-1907, 1935-1949 and 1953-2011. During the instrumental period (1951-2011, an obvious warming trend appeared in the last twenty years. The reconstruction displayed similar patterns to a temperature reconstruction from the east-central Tibetan Plateau at the inter-decadal timescale, indicating that the temperature reconstruction in this study was a reliable proxy for Northwest China. It was also found that the reconstruction series had good consistency with the Northern Hemisphere temperature at a decadal timescale. Multi-taper method spectral analysis detected some low- and high-frequency cycles (2.3-2.4-year, 2.8-year, 3.4-3.6-year, 5.0-year, 9.9-year and 27.0-year. Combining these cycles, the relationship of the low-frequency change with the Pacific Decadal Oscillation (PDO, North Atlantic Oscillation (NAO and Southern Oscillation (SO suggested that the reconstructed temperature variations may be related to large-scale atmospheric-oceanic variations. Major volcanic eruptions were partly reflected in the reconstructed temperatures after high-pass filtering; these events promoted anomalous cooling in this region. The results of this study not only provide new information for assessing the long-term temperature changes in the Hexi Corridor of Northwest China, but also further demonstrate the effects of large-scale atmospheric-oceanic circulation on climate change in Northwest China.

  11. StreamNet; Northwest Aquatic Resource Information Network - Status of Salmon and Steelhead in the Columbia River Basin, 1995 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Duane A.; Beamesderfer, Raymond C. [Oregon Dept. of Fish and Wildlife, Enterprise, OR (United States); Woodard, Bob [Washington Dept. of Fish and Wildlife, Olympia, WA (United States)

    1996-04-01

    Information on fish populations, fisheries, and fish habitat is crucial to the success of ongoing program to protect, recover, enhance, and manage fish resources in the Columbia River Basin. However, pertinent data are often difficult to locate because it is scattered among many agencies and is often unpublished. The goal of this annual report is to bring many diverse data types and sources into a single comprehensive report on the status of anadromous fish runs in the Columbia River Basin and the environmental conditions that may affect that status. Brief summaries are provided to identify the type and scope of available information. This synopsis is intended to complement other more detailed reports to which readers are referred for comprehensive treatment of specific subjects. This first report focuses mainly on anadromous salmon and steelhead (primarily through 1994) but the authors intend to expand the scope of future issues to include resident species. This is the first of what the authors intend to be an annual report. They welcome constructive suggestions for improvements. This report is a product of the StreamNet (formerly Coordinated Information System and Northwest Environmental Data Base) project which is a part of the Bonneville Power Administration`s program to protect, mitigate, and enhance fish and wildlife affected by the development and operation of hydroelectric facilities on the Columbia River and its tributaries. The project is called for in the Fish and Wildlife Program of the Northwest Power Planning Council. The project`s objective is to promote exchange and dissemination of information in a standardized electronic format throughout the basin. This project is administered by the Pacific States Marine Fisheries Commission with active participation by tribal, state, and federal fish and wildlife agencies.

  12. Joint inversion of high resolution S-wave velocity structure underneath North China Basin

    Science.gov (United States)

    Yang, C.; Li, G.; Niu, F.

    2017-12-01

    North China basin is one of earthquake prone areas in China. Many devastating earthquakes occurred in the last century and before, such as the 1937 M7.0 Heze Earthquake in Shandong province, the 1966 M7.2 Xingtai Earthquake and 1976 Tangshan Earthquake in Hebei province. Knowing the structure of the sediment cover is of great importance to predict strong ground motion caused by earthquakes. Unconsolidated sediments are loose materials, ranging from clay to sand to gravel. Earthquakes can liquefy unconsolidated sediments, thus knowing the distribution and thickness of the unconsolidated sediments has significant implication in seismic hazard analysis of the area. Quantitative estimates of the amount of extension of the North China basin is important to understand the thinning and evolution of the eastern North China craton and the underlying mechanism. In principle, the amount of lithospheric stretching can be estimated from sediment and crustal thickness. Therefore an accurate estimate of the sediment and crustal thickness of the area is also important in understanding regional tectonics. In this study, we jointly invert the Rayleigh wave phase-velocity dispersion and Z/H ratio data to construct a 3-D S-wave velocity model beneath North China area. We use 4-year ambient noise data recorded from 249 temporary stations, and 139 earthquake events to extract Rayleigh wave Z/H ratios. The Z/H ratios obtained from ambient noise data and earthquake data show a good agreement within the overlapped periods. The phase velocity dispersion curve was estimated from the same ambient noise data. The preliminary result shows a relatively low Z/H ratio and low velocity anomaly at the shallow part of sediment basins.

  13. The influence of large-scale climate phenomena on precipitation in the Ordos Basin, China

    Science.gov (United States)

    Zhong, Yu; Lei, Liyuan; Liu, Youcun; Hao, Yonghong; Zou, Chris; Zhan, Hongbin

    2017-11-01

    Large-scale atmospheric circulations significantly affect regional precipitation patterns. However, it is not well known whether and how these phenomena affect regional precipitation distribution in northern China. This paper reported the individual and coupled effects of El Niño-Southern Oscillation (ENSO), Indian summer monsoon (ISM), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO) on annual precipitation for the Ordos Basin, an arid and semi-arid basin, currently with major industries of coal, fossil oil, natural gas, and halite in north central China. Our results showed that ENSO and ISM exerted substantial impact on annual precipitation while the impact of PDO and AMO was relatively limited. There were 24 and 15 out of 33 stations showing significant differences ( p e., Hobq Desert and Mu Us Sandy Land) in the center of the basin were less affected by these large-scale climatic phenomena. An improved understanding of such relationships would be helpful in water resource planning and disaster management for the Ordos Basin.

  14. Hydrological long-term dry and wet periods in the Xijiang River basin, South China

    Directory of Open Access Journals (Sweden)

    T. Fischer

    2013-01-01

    Full Text Available In this study, hydrological long-term dry and wet periods are analyzed for the Xijiang River basin in South China. Daily precipitation data of 118 stations and data on daily discharge at Gaoyao hydrological station at the mouth of the Xijiang River for the period 1961–2007 are used. At a 24-month timescale, the standardized precipitation index (SPI-24 for the six sub-basins of the Xijiang River and the standardized discharge index (SDI-24 for Gaoyao station are applied. The monthly values of the SPI-24 averaged for the Xijiang River basin correlate highly with the monthly values of the SDI-24. Distinct long-term dry and wet sequences can be detected.

    The principal component analysis is applied and shows spatial disparities in dry and wet periods for the six sub-basins. The correlation between the SPI-24 of the six sub-basins and the first principal component score shows that 67% of the variability within the sub-basins can be explained by dry and wet periods in the east of the Xijiang River basin. The spatial dipole conditions (second and third principal component explain spatiotemporal disparities in the variability of dry and wet periods. All sub-basins contribute to hydrological dry periods, while mainly the northeastern sub-basins cause wet periods in the Xijiang River. We can also conclude that long-term dry events are larger in spatial extent and cover all sub-basins while long-term wet events are regional phenomena.

    A spectral analysis is applied for the SPI-24 and the SDI-24. The results show significant peaks in periodicities of 11–14.7 yr, 2.8 yr, 3.4–3.7 yr, and 6.3–7.3 yr. The same periodic cycles can be found in the SPI-24 of the six sub-basins but with some variability in the mean magnitude. A wavelet analysis shows that significant periodicities have been stable over time since the 1980s. Extrapolations of the reconstructed SPI-24 and SDI-24 represent the continuation of observed significant periodicities

  15. Awareness and Attitudes About HIV Among Pregnant Women in Aksu, Northwest China

    OpenAIRE

    Maimaiti, Rena; Andersson, Rune

    2008-01-01

    The Xinjiang Uyghur Autonomous Region has a firmly established HIV epidemic among its intravenous drug user (IDU) population. Local sex workers were also found to be positive in 1998. A descriptive, cross-sectional survey of knowledge about HIV/AIDS and attitudes among consecutively selected pregnant women was conducted November 2005 in Aksu Prefecture, north-western China, with a population on 2 million with about 25?000 pregnancies per year. A total of 291 pregnant women participated. We fo...

  16. Model Prediction of Secondary Soil Salinization in the Keriya Oasis, Northwest China

    OpenAIRE

    Jumeniyaz Seydehmet; Guang Hui Lv; Ilyas Nurmemet; Tayierjiang Aishan; Abdulla Abliz; Mamat Sawut; Abdugheni Abliz; Mamattursun Eziz

    2018-01-01

    Significant anthropogenic and biophysical changes have caused fluctuations in the soil salinization area of the Keriya Oasis in China. The Driver-Pressure-State-Impact-Response (DPSIR) sustainability framework and Bayesian networks (BNs) were used to integrate information from anthropogenic and natural systems to model the trend of secondary soil salinization. The developed model predicted that light salinization (vegetation coverage of around 15–20%, soil salt 5–10 g/kg) of the ecotone will ...

  17. Lake-level Fluctuation and Climate Cyclicity Observed in Lake Strata in the Northwestern Qaidam Basin, China

    Science.gov (United States)

    Riegel, H. B.; Heermance, R. V., III; Nie, J.; Su, Q.; Garzione, C. N.

    2015-12-01

    The Pliocene and Quaternary are times of rapid, extreme climate variability, but 3-D geologic exposures of lacustrine strata from this time are rare, impeding observations of the impact of climate-change on lake sedimentation. The Qaidam Basin (QB) in western China provides a unique geologic setting, where internally drained lakes have existed for the past few million years, and recent deformation of the basin floor has uplifted and exposed lacustrine strata. This stratigraphy records a detailed history of lake level fluctuation, evaporite deposition, and climate change. We provide new paleomagnetic, δ18O and δ13C data combined with detailed sedimentology from the lower 475 m of a 900 m thick stratigraphic section (38.28N, 91.54E) in the northwestern QB to reveal a high-resolution record of sedimentation and climate change during the Plio-Quaternary. 12 magnetozones indicate an age for the lower half of the section between 6.0-3.0 Ma. The section consists of 9 lithofacies (1 mudstone, 4 sandstone, 1 conglomerate, 2 gypsum, 1 halite) that can be divided into 3 stratigraphic units based on evaporite concentration. Alternating mud, gypsum, and halite beds imply multiple lake-level fluctuations and occasional complete drying of the lake. This is consistent with >12.5‰ variation in the δ18O values of lacustrine carbonates (δ18Oc), indicating large-scale lake level fluctuation below 410 m, consistent with the boundary of Unit 1 and 2. Between 410 and 475 m, the δ18Oc values are ~-5 ‰. Above 475 m, an increase in gypsum concentration causes a thick salt-crust to develop on the outcrop, making sampling impossible. This stratigraphic level corresponds to an age of ~3.0 Ma, when the QB became hyper-arid. The presence of gypsum and halite throughout the section implies that the QB was arid and internally drained by at least 6 Ma, although the basin may have been divided into multiple lakes based on the bimodal δ18O values from different parts of the QB during that

  18. Soil erodibility mapping using the RUSLE model to prioritize erosion control in the Wadi Sahouat basin, North-West of Algeria.

    Science.gov (United States)

    Toubal, Abderrezak Kamel; Achite, Mohammed; Ouillon, Sylvain; Dehni, Abdelatif

    2018-03-12

    Soil losses must be quantified over watersheds in order to set up protection measures against erosion. The main objective of this paper is to quantify and to map soil losses in the Wadi Sahouat basin (2140 km 2 ) in the north-west of Algeria, using the Revised Universal Soil Loss Equation (RUSLE) model assisted by a Geographic Information System (GIS) and remote sensing. The Model Builder of the GIS allowed the automation of the different operations for establishing thematic layers of the model parameters: the erosivity factor (R), the erodibility factor (K), the topographic factor (LS), the crop management factor (C), and the conservation support practice factor (P). The average annual soil loss rate in the Wadi Sahouat basin ranges from 0 to 255 t ha -1  year -1 , maximum values being observed over steep slopes of more than 25% and between 600 and 1000 m elevations. 3.4% of the basin is classified as highly susceptible to erosion, 4.9% with a medium risk, and 91.6% at a low risk. Google Earth reveals a clear conformity with the degree of zones to erosion sensitivity. Based on the soil loss map, 32 sub-basins were classified into three categories by priority of intervention: high, moderate, and low. This priority is available to sustain a management plan against sediment filling of the Ouizert dam at the basin outlet. The method enhancing the RUSLE model and confrontation with Google Earth can be easily adapted to other watersheds.

  19. Performance of RegCM4 over major river basins in China

    Science.gov (United States)

    Gao, Xuejie; Shi, Ying; Han, Zhenyu; Wang, Meili; Wu, Jia; Zhang, Dongfeng; Xu, Ying; Giorgi, Filippo

    2017-04-01

    A long-term simulation for the period 1990-2010 is conducted with the latest version of the International Centre for Theoretical Physics' Regional Climate Model (RegCM4), driven by ERA-Interim boundary conditions at a grid spacing of 25 km. The Community Land Model (CLM) is used to describe land surface processes, with updates in the surface parameters, including the land cover and surface emissivity. The simulation is compared against observations to evaluate the model performance in reproducing the present day climatology and interannual variability over the 10 main river basins in China, with focus on surface air temperature and precipitation. Temperature and precipitation from the ERA-Interim reanalysis are also considered in the model assessment. Results show that the model reproduces the present day climatology over China and its main river basins, with better performances in June-July-August compared to December-January-February (DJF). In DJF, we find a warm bias at high latitudes, underestimated precipitation in the south, and overestimated precipitation in the north. The model in general captures the observed interannual variability, with greater skill for temperature. We also find an underestimation of heavy precipitation events in eastern China, and an underestimation of consecutive dry days in northern China and the Tibetan Plateau. Similar biases for both mean climatology and extremes are found in the ERA-Interim reanalysis, indicating the difficulties for climate models in simulating extreme monsoon climate events over East Asia.

  20. Farmers' Perception and Adaptation Behavior Concerning Land Degradation: A Theoretical Framework and a Case Study in Northwest China

    Science.gov (United States)

    Hou, Deyi; Liu, Kai

    2017-04-01

    In an era of global environmental change, social actors from an individual level to a national level are increasingly seeking adaptation strategies to better manage risks from environmental hazards. Vulnerability arises where adaptation capacity is not sufficient in dealing with a changing environment. Adaptation on an individual level and community level is important because of the location specific nature of environmental change. Land degradation is drawing much attention from both governments and academics, because it tends to affect the most vulnerable human populations and ecological systems most significantly. Despite these efforts, there is limited scientific knowledge regarding how farmers at a local level perceive the risks associated with degraded land and how their background, attitude, and living situation may affect their adaptation behavior. This poses a challenge to policy makers who are tasked to enhance the resilience of the society in response to environmental changes. Degradation of land by pollutant chemicals is particularly serious in China due to aggressive urbanization and industrialization activities over the last four decades. A report by the Ministry of Environmental Protection (MEP) in 2014 suggested that 16.1 percent of the nation's soil is polluted. Other studies suggest that shallow groundwater contamination is even more wide spread, with 80 90 percent being polluted. The government has realized the seriousness of land contamination, and vowed to give high priority to land remediation. Millions of hectares of contaminated agricultural land are expected to be remediated over the next decade. However, farmer's perception and adaptation behavior under this social and environmental change remain unknown. In this presentation, we report a conceptual framework and research hypothesis based on theoretical methodologies found in existing literature. We applied this framework to a case study of degraded land in an arid region in Northwest of

  1. Validation of a Process-Based Agro-Ecosystem Model (Agro-IBIS for Maize in Xinjiang, Northwest China

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    Tureniguli Amuti

    2018-03-01

    Full Text Available Agricultural oasis expansion and intensive management practices have occurred in arid and semiarid regions of China during the last few decades. Accordingly, regional carbon and water budgets have been profoundly impacted by agroecosystems in these regions. Therefore, study on the methods used to accurately estimate energy, water, and carbon exchanges is becoming increasingly important. Process-based models can represent the complex processes between land and atmosphere among agricultural ecosystems. However, before the models can be applied they must be validated under different environmental and climatic conditions. In this study, a process-based agricultural ecosystem model (Agro-IBIS was validated for maize crops using 3 years of soil and biometric measurements at Wulanwusu agrometeorological site (WAS located in the Shihezi oasis in Xinjiang, northwest China. The model satisfactorily represented leaf area index (LAI during the growing season, simulating its peak values within the magnitude of 0–10%. The total biomass carbon was overestimated by 15%, 8%, and 16% in 2004, 2005, and 2006, respectively. The model satisfactorily simulated the soil temperature (0–10 cm and volumetric water content (VWC (0–25 cm of farmland during the growing season. However, it overestimated soil temperature approximately by 4 °C and VWC by 15–30% during the winter, coinciding with the period of no vegetation cover in Xinjiang. Overall, the results indicate that the model could represent crop growth, and seems to be applicable in multiple sites in arid oases agroecosystems of Xinjiang. Future application of the model will impose more comprehensive validation using eddy covariance flux data, and consider including dynamics of crop residue and improving characterization of the final stage of leaf development.

  2. Effects of dripper discharge and irrigation frequency on growth and yield of maize in loess plateau of northwest china

    International Nuclear Information System (INIS)

    Xiukang, W.; Zhanbin, L.; Yingying, X.

    2014-01-01

    A field experiment was conducted at the Changwu Experimental Station in Changwu County, Shaanxi Province, in northwestern China from 2010 to 2011 with four treatments and six replicates in a randomized complete block design to determine appropriate dripper discharge and irrigation frequency for maize (Zea mays, L.) irrigated by drip irrigated system. Dripper discharge was applied to maize 1L/h of dripper discharge, 2 days irrigation frequency and 100% of evaporation from a class a pan (T1), 2, 3 and 4 L/h corresponding to 4, 6 and 8 days irrigation frequency, and deficit irrigation water levels was 90%, 80% and 70% of evaporation (T2, T3 and T4), respectively. The results indicated that longest root, root activity, plant height, leaf area, biomass and grain yields values were highest in T1 in both years. The highest grain yield was obtained of 8.78 and 8.84 t ha-1 under T1 in both years, and the minimum yield was obtained with 8.15 and 7.78 t ha-1 under T4 in 2010 and 2011, respectively. The maximum irrigation water use efficiency (IWUE) was 3.247 and 3.283 kg m-3 in both years under T4. Despite the reduction of growth and grain yield in T3, the dripper discharge was 3L/h, 6 days irrigation frequency and 80% of evaporation was still high and acceptable for maize production and irrigation water use efficiency in Loess Plateau of Northwest China. (author)

  3. Small rural communities in the inland Northwest: an assessment of small communities in the interior and upper Columbia River basins.

    Science.gov (United States)

    Charles C. Harris; William McLaughlin; Greg Brown; Dennis R. Becker

    2000-01-01

    An assessment of small rural communities in the interior and upper Columbia River basin was conducted for the Interior Columbia Basin Ecosystem Management Project (ICBEMP). The characteristics and conditions of the rural communities in this region, which are complex and constantly changing, were examined. The research also assessed the resilience of the region’s...

  4. Different Effects of Regional Species Pool on Plant Diversity between Forest and Grassland Biomes in Arid Northwest China.

    Science.gov (United States)

    Li, Liping; Liu, Yining; Wang, Xiangping; Fang, Jingyun; Wang, Qingchun; Zhang, Bengang; Xiao, Peigen; Mohammat, Anwar; Terwei, André

    2015-01-01

    Species pool hypothesis is broadly known and frequently tested in various regions and vegetation types. However it has not been tested in the arid Xinjiang region of China due to lack of data. Here with systematic data from references and field survey, we comprehensively examined species pool hypothesis in this region. Took species richness in 0.1° × 0.1° grid cells as regional species richness (RSR) which were obtained from the distribution maps of vascular plant species, and took species diversity of 190 and 103 plots in forest and grassland biomes across Xinjiang as local species richness (LSR), together with the digitalized soil pH and climate data, we tested the species pool hypothesis in this region. We found that: (1) the average RSR was higher in mountains than that in basins and it was negatively correlated with soil pH in mountains while positively correlated with soil pH in basins in Xinjiang; (2) RSR showed a positive correlation with mean annual precipitation (MAP) while showed a hump-shaped pattern with mean annual temperature (MAT); and the changing patterns of LSR were different for forest and grassland along the geographical and climate gradients; (3) LSR of forest was more affected by RSR than by climate, while on the contrary, LSR of grassland was more affected by climate than by RSR. Our results validated the species pool hypothesis in revealing that RSR had a significant role in shaping LSR patterns in addition to climate. We concluded that the relative effects of climate vs. RSR on LSR differed markedly between the forest and grassland communities across Xinjiang. Our results also showed that RSR revealed a contrasting relationship with soil pH in mountains and in basins, which might reflect differences in evolutionary processes of various habitats. In summary, our research systematically analyzed the correlation of species richness in regional and local scales in Xinjiang which provides more insights into the understanding of species pool

  5. Modelling irrigated maize with a combination of coupled-model simulation and uncertainty analysis, in the northwest of China

    Directory of Open Access Journals (Sweden)

    Y. Li

    2012-05-01

    Full Text Available The hydrologic model HYDRUS-1-D and the crop growth model WOFOST are coupled to efficiently manage water resources in agriculture and improve the prediction of crop production. The results of the coupled model are validated by experimental studies of irrigated-maize done in the middle reaches of northwest China's Heihe River, a semi-arid to arid region. Good agreement is achieved between the simulated evapotranspiration, soil moisture and crop production and their respective field measurements made under current maize irrigation and fertilization. Based on the calibrated model, the scenario analysis reveals that the most optimal amount of irrigation is 500–600 mm in this region. However, for regions without detailed observation, the results of the numerical simulation can be unreliable for irrigation decision making owing to the shortage of calibrated model boundary conditions and parameters. So, we develop a method of combining model ensemble simulations and uncertainty/sensitivity analysis to speculate the probability of crop production. In our studies, the uncertainty analysis is used to reveal the risk of facing a loss of crop production as irrigation decreases. The global sensitivity analysis is used to test the coupled model and further quantitatively analyse the impact of the uncertainty of coupled model parameters and environmental scenarios on crop production. This method can be used for estimation in regions with no or reduced data availability.

  6. An Integrative Approach to Understand the Climatic-Hydrological Process: A Case Study of Yarkand River, Northwest China

    Directory of Open Access Journals (Sweden)

    Jianhua Xu

    2013-01-01

    Full Text Available Taking the Yarkand River as an example, this paper conducted an integrative approach combining the Durbin-Watson statistic test (DWST, multiple linear regression (MLR, wavelet analysis (WA, coefficient of determination (CD, and Akaike information criterion (AIC to analyze the climatic-hydrological process of inland river, Northwest China from a multitime scale perspective. The main findings are as follows. (1 The hydrologic and climatic variables, that is, annual runoff (AR, annual average temperature, (AAT and annual precipitation (AP, are stochastic and, no significant autocorrelation. (2 The variation patterns of runoff, temperature, and precipitation were scale dependent in time. AR, AAT, and AP basically present linear trends at 16-year and 32-year scales, but they show nonlinear fluctuations at 2-year and 4-year scales. (3 The relationship between AR with AAT and AP was simulated by the multiple linear regression equation (MLRE based on wavelet analysis at each time scale. But the simulated effect at a larger time scale is better than that at a smaller time scale.

  7. Groundwater and surface-water interactions and impacts of human activities in the Hailiutu catchment, northwest China

    Science.gov (United States)

    Yang, Zhi; Zhou, Yangxiao; Wenninger, Jochen; Uhlenbrook, Stefan; Wang, Xusheng; Wan, Li

    2017-08-01

    The interactions between groundwater and surface water have been significantly affected by human activities in the semi-arid Hailiutu catchment, northwest China. Several methods were used to investigate the spatial and temporal interactions between groundwater and surface water. Isotopic and chemical analyses of water samples determined that groundwater discharges to the Hailiutu River, and mass balance equations were employed to estimate groundwater seepage rates along the river using chemical profiles. The hydrograph separation method was used to estimate temporal variations of groundwater discharges to the river. A numerical groundwater model was constructed to simulate groundwater discharges along the river and to analyze effects of water use in the catchment. The simulated seepage rates along the river compare reasonably well with the seepage estimates derived from a chemical profile in 2012. The impacts of human activities (river-water diversion and groundwater abstraction) on the river discharge were analyzed by calculating the differences between the simulated natural groundwater discharge and the measured river discharge. Water use associated with the Hailiutu River increased from 1986 to 1991, reached its highest level from 1992 to 2000, and decreased from 2001 onwards. The reduction of river discharge might have negative impacts on the riparian ecosystem and the water availability for downstream users. The interactions between groundwater and surface water as well as the consequences of human activities should be taken into account when implementing sustainable water resources management in the Hailiutu catchment.

  8. Sensitivity of the reference evapotranspiration to key climatic variables during the growing season in the Ejina oasis northwest China.

    Science.gov (United States)

    Hou, Lan-Gong; Zou, Song-Bing; Xiao, Hong-Lang; Yang, Yong-Gang

    2013-01-01

    The standardized FAO56 Penman-Monteith model, which has been the most reasonable method in both humid and arid climatic conditions, provides reference evapotranspiration (ETo) estimates for planning and efficient use of agricultural water resources. And sensitivity analysis is important in understanding the relative importance of climatic variables to the variation of reference evapotranspiration. In this study, a non-dimensional relative sensitivity coefficient was employed to predict responses of ETo to perturbations of four climatic variables in the Ejina oasis northwest China. A 20-year historical dataset of daily air temperature, wind speed, relative humidity and daily sunshine duration in the Ejina oasis was used in the analysis. Results have shown that daily sensitivity coefficients exhibited large fluctuations during the growing season, and shortwave radiation was the most sensitive variable in general for the Ejina oasis, followed by air temperature, wind speed and relative humidity. According to this study, the response of ETo can be preferably predicted under perturbation of air temperature, wind speed, relative humidity and shortwave radiation by their sensitivity coefficients.

  9. [Soil sandy desertification and salinization and their interrelationships in Yanghuang irrigated area of Hongsipu, Ningxia of northwest China].

    Science.gov (United States)

    Yang, Xin-guo; Song, Nai-ping

    2011-09-01

    By the methods of controlled and typical sampling, this paper analyzed the texture, salinization characteristics, cation exchange capacity (CEC), and their correlations in the 0-40 cm soil profiles of corn land, medlar land, and non-utilized land in Yanghuang irrigated area of Hongsipu, Northwest China. Under controlled sampling, the salt content in the soil profiles was 0.69-1.30 g x kg(-1) (except in non-utilized land where the 0-10 cm soil salt content was up to 1.74 g x kg(-1)), with no obvious salinization. The sodium adsorption ratio and exchangeable sodium percentage in the 20-40 cm soil layer of medlar land were 12.18 and 14.1%, respectively, and the total content of clay and silt in the 0-40 cm soil profile of medlar land was up to 37.3% whereas that in the 0-20 cm soil layer of corn land was only 13.5%. In the 20-40 cm soil layer of corn land, the indices of sandy desertification and salinization had significant correlations under controlled sampling but no correlations under typical sampling, while the CEC and the sandy desertification and salinization indices had significant correlations under typical sampling. In different land use types in the study area, soil sandy desertification and salinization had complicated interrelationships, and CEC could be used as the indicator for the changes in soil environmental quality.

  10. Forest Evapotranspiration and Energy Flux Partitioning Based on Eddy Covariance Methods in an Arid Desert Region of Northwest China

    Directory of Open Access Journals (Sweden)

    Xiaohong Ma

    2017-01-01

    Full Text Available In this study, the characteristics of energy flux partitioning and evapotranspiration of P. euphratica forests were examined in the extreme arid region of Northwest China. Energy balance closure of the ecosystem was approximately 72% (H + LE = 0.72 ∗ (Rn-G+7.72, r2=0.79, n=12095, where Rn is the net radiation, G is the soil heat flux, H is the sensible heat flux, and LE is the latent heat flux. LE was the main term of energy consumption at annual time scale because of higher value in the growing season. The ratios of the latent (LE and sensible (H heat fluxes to net radiation were 0.47 and 0.28 throughout the year, respectively. Moreover, the yearly evapotranspiration of P. euphratica forests was 744 mm year−1. And the mean daily ET was 5.09 mm·d−1 in the vibrant growing season. In particular, a small spike in the actual evapotranspiration distribution occurred during the soil ablation period due to the higher temperature and sufficient soil moisture associated with soil thawing. This period is accompanied by a series of physical processes, such as moisture transfer and heat exchange.

  11. Spatial distribution of Qinghai spruce forests and the thresholds of influencing factors in a small catchment, Qilian Mountains, northwest China.

    Science.gov (United States)

    Yang, Wenjuan; Wang, Yanhui; Wang, Shunli; Webb, Ashley A; Yu, Pengtao; Liu, Xiande; Zhang, Xuelong

    2017-07-17

    Forest restoration in dryland mountainous areas is extremely difficult due to dry climate, complex topography and accelerating climate change. Thus, exact identification of suitable sites is required. This study at a small watershed of Qilian Mountains, Northwest China, aimed to determine the important factors and their thresholds limiting the spatial distribution of forests of Qinghai spruce (Picea crassifolia), a locally dominant tree species. The watershed was divided into 342 spatial units. Their location, terrain and vegetation characteristics were recorded. Statistical analysis showed that the potential distribution area of Qinghai spruce forests is within an ellipse with the axes of elevation (from 2673.6 to 3202.2 m a.s.l.) and slope aspect (from -162.1° to 75.1° deviated from North). Within this ellipse, the forested sites have a soil thickness ≥40 cm, and slope positions of lower-slope, lower- or middle-slope, anywhere if the elevation is 2900 m a.s.l, respectively. The corresponding mean annual air temperature at upper elevation boundary is -2.69 °C, while the mean annual precipitation at lower elevation boundary is 374 (331) mm within the small watershed (study area). The high prediction accuracy using these 4 factors can help to identify suitable sites and increase the success of afforestation.

  12. Controlling factors of volcanic hydrocarbon reservoirs in Bohai Bay Basin, China

    Directory of Open Access Journals (Sweden)

    Chun Yang

    2017-12-01

    Full Text Available Volcanic hydrocarbon reservoirs are developed in the Mesozoic and Cenozoic strata in Bohai Bay Basin in China. There is more than one hundred million tons of proven oil reserves in the said reservoir. They performed different actors for oil and gas accumulation in the basin. Faults controlled the distribution and accumulation of oil and gas related to volcanic rocks in Bohai Bay Basin. Not to mention, the zone near the faults is favorable for the development of good reservoirs. Volcanic rocks and volcanism can serve several roles during the course of hydrocarbon generation and accumulation. Volcanism can promote hydrocarbon generation from source rocks. Simultaneously, volcanic activity can damage petroleum reservoirs. Volcanic rocks can be both the reservoirs and the cap-rocks or obscured layer in the basin. The occurrence of volcanic rocks in source rocks can form fractures more easily compared to that in sandstones. Finally, volcanic rocks also control the distribution of mantle-derived CO2 gas reservoirs in the basin.

  13. Geophysical prospecting for the deep geothermal structure of the Zhangzhou basin, Southeast China

    Science.gov (United States)

    Wu, Chaofeng; Liu, Shuang; Hu, Xiangyun; Wang, Guiling; Lin, Wenjing

    2017-04-01

    Zhangzhou basin located at the Southeast margins of Asian plate is one of the largest geothermal fields in Fujian province, Southeast China. High-temperature natural springs and granite rocks are widely distributed in this region and the causes of geothermal are speculated to be involved the large number of magmatic activities from Jurassic to Cretaceous periods. To investigate the deep structure of Zhangzhou basin, magnetotelluric and gravity measurements were carried out and the joint inversion of magnetotelluric and gravity data delineated the faults and the granites distributions. The inversion results also indicated the backgrounds of heat reservoirs, heat fluid paths and whole geothermal system of the Zhangzhou basin. Combining with the surface geological investigation, the geophysical inversion results revealed that the faults activities and magma intrusions are the main reasons for the formation of geothermal resources of the Zhangzhou basin. Upwelling mantle provides enormous heats to the lower crust leading to metamorphic rocks to be partially melt generating voluminous magmas. Then the magmas migration and thermal convection along the faults warm up the upper crust. So finally, the cap rocks, basements and major faults are the three favorable conditions for the formation of geothermal fields of the Zhangzhou basin.

  14. Impacts of local circulations on the wintertime air pollution in the Guanzhong Basin, China.

    Science.gov (United States)

    Bei, Naifang; Zhao, Linna; Xiao, Bo; Meng, Ning; Feng, Tian

    2017-08-15

    Urbanization and industrialization in the recent 30years have caused frequent heavy haze pollution in the Guanzhong basin, China during wintertime. Based on the categorized large-scale synoptic situations, the local circulation and its impact on the air pollution in the basin have been investigated using observational data analyses and model simulations with the WRF-CHEM model. The simulated mountain-valley breeze circulations are well established under most of the large-scale synoptic situations in the south-north direction. The downward mountain-breeze not only causes the convergence zone in the basin but also tends to bring the pollutants back from the mountain areas to the basin and enhance pollutants concentrations in the evening. The intensity of the mountain-valley breeze circulations may be different under different synoptic situations, but in general, aside emissions, every pollution event is the synthetic result of the synoptic situation at the large scale and the local circulation at the small scale in the Guanzhong basin. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Sources identification and pollution evaluation of heavy metals in the surface sediments of Bortala River, Northwest China.

    Science.gov (United States)

    Zhang, Zhaoyong; Juying, Li; Mamat, Zulpiya; QingFu, Ye

    2016-04-01

    The current study focused on the Bortala River - a typical inland river located in an oasis of arid area in northwestern China. The sediment and soil samples were collected from the river and drainage basin. Results showed that: (1) the particle size of the sand fraction of the sediments was 78-697 µm, accounting for 78.82% of the total samples; the average concentrations of eight heavy metals fell within the concentration ranges recommended by the Secondary National Standard of China, while the maximum concentrations of Pb, Cd, and Hg exceeded these standards; (2) results from multivariate statistical analysis indicated that Cu, Ni, As, and Zn originated primarily from natural geological background, while Cd, Pb, Hg and Cr in the sediments originated from human activities; (3) results of the enrichment factor analysis and the geo-accumulation index evaluation showed that Cd, Hg, and Pb were present in the surface sediments of the river at low or partial serious pollution levels, while Zn, Cr, As, Ni, and Cu existed at zero or low pollution levels; (4) calculation of the potential ecological hazards index showed that among the eight tested heavy metals, Cd, Pb, Hg, and Cr were the main potential ecological risk factors, with relative contributions of 25.43%, 22.23%, 21.16%, and 14.87%, respectively; (5) the spatial distribution of the enrichment factors (EF(S)), the Geo-accumulation index (I(geo)), and the potential ecological risk coefficient (E(r)(i)) for eight heavy metals showed that there was a greater accumulation of heavy metals Pb, Cd, and Hg in the sediments of the central and eastern parts of the river. Results of this research can be a reference for the heavy metals pollution prevention, the harmony development of the ecology protection and the economy development of the oases of inland river basin of arid regions of China, Central Asia and also other parts of the world. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Patterns of Livestock Predation by Carnivores: Human-Wildlife Conflict in Northwest Yunnan, China

    Science.gov (United States)

    Li, Xueyou; Buzzard, Paul; Chen, Yongchun; Jiang, Xuelong

    2013-12-01

    Alleviating human-carnivore conflict is central to large carnivore conservation and is often of economic importance, where people coexist with carnivores. In this article, we report on the patterns of predation and economic losses from wild carnivores preying on livestock in three villages of northern Baima Xueshan Nature Reserve, northwest Yunnan during a 2-year period between January 2010 and December 2011. We analyzed claims from 149 households that 258 head of livestock were predated. Wolves ( Canis lupus) were responsible for 79.1 % of livestock predation; Asiatic black bears ( Selenarctos thibetanus) and dholes ( Cuon alpinus) were the other predators responsible. Predation frequency varied between livestock species. The majority of livestock killed were yak-cattle hybrids or dzo (40.3 %). Wolves killed fewer cattle than expected, and more donkeys and horses than expected. Wolves and bears killed more adult female and fewer adult male livestock than expected. Intensified predation in wet season coincided with livestock being left to graze unattended in alpine meadows far away from villages. On average, carnivore attacks claimed 2.1 % of range stock annually. This predation represented an economic loss of 17 % (SD = 14 %) of the annual household income. Despite this loss and a perceived increase in carnivore conflict, a majority of the herders (66 %) still supported the reserve. This support is primarily due to the benefits from the collection of nontimber resources such as mushrooms and medicinal plants. Our study also suggested that improvement of husbandry techniques and facilities will reduce conflicts and contribute to improved conservation of these threatened predators.

  17. Groundwater Quality in Jingyuan County, a Semi-Humid Area in Northwest China

    Directory of Open Access Journals (Sweden)

    Wu Jianhua

    2011-01-01

    Full Text Available Groundwater quality assessment is an essential study which plays an important role in the rational development and utilization of groundwater in any part of the world. In the study, groundwater qualities in Jingyuan County, in Ningxia, China were assessed with entropy weighted water quality index method. In the assessment, 12 hydrochemical parameters including chloride, sulphate, sodium, iron, pH, total dissolved solid (TDS, total hardness (TH, nitrate, ammonia, nitrogen, fluoride, iodine and nitrite were selected. The assessment results show that the concentrations of iodine, TH, iron and TDS are the most influencing parameters affecting the groundwater quality. The assessment results are rational and are in consistency with the results of filed investigation of which both indicates the groundwater in Jingyuan County is fit for drinking.

  18. Simulation of blue and green water resources in the Wei River basin, China

    Directory of Open Access Journals (Sweden)

    Z. Xu

    2014-09-01

    Full Text Available The Wei River is the largest tributary of the Yellow River in China and it is suffering from water scarcity and water pollution. In order to quantify the amount of water resources in the study area, a hydrological modelling approach was applied by using SWAT (Soil and Water Assessment Tool, calibrated and validated with SUFI-2 (Sequential Uncertainty Fitting program based on river discharge in the Wei River basin (WRB. Sensitivity and uncertainty analyses were also performed to improve the model performance. Water resources components of blue water flow, green water flow and green water storage were estimated at the HRU (Hydrological Response Unit scales. Water resources in HRUs were also aggregated to sub-basins, river catchments, and then city/region scales for further analysis. The results showed that most parts of the WRB experienced a decrease in blue water resources between the 1960s and 2000s, with a minimum value in the 1990s. The decrease is particularly significant in the most southern part of the WRB (Guanzhong Plain, one of the most important grain production basements in China. Variations of green water flow and green water storage were relatively small on the spatial and temporal dimensions. This study provides strategic information for optimal utilization of water resources and planning of cultivating seasons in the Wei River basin.

  19. Temporal-spatial evolution of the hydrologic drought characteristics of the karst drainage basins in South China

    Science.gov (United States)

    He, Zhonghua; Liang, Hong; Yang, Chaohui; Huang, Fasu; Zeng, Xinbo

    2018-02-01

    Hydrologic drought, as a typical natural phenomenon in the context of global climate change, is the extension and development of meteorological and agricultural droughts, and it is an eventual and extreme drought. This study selects 55 hydrological control basins in Southern China as research areas. The study analyzes features, such as intensity and occurrence frequency of hydrologic droughts, and explores the spatial-temporal evolution patterns in the karst drainage basins in Southern China by virtue of Streamflow Drought Index. Results show that (1) the general hydrologic droughts from 1970s to 2010s exhibited ;an upward trend after having experienced a previous decline; in the karst drainage basins in Southern China; the trend was mainly represented by the gradual alleviation of hydrologic droughts from 1970s to 1990s and the gradual aggravation from 2000s to 2010s. (2) The spatial-temporal evolution pattern of occurrence frequency in the karst drainage basins in Southern China was consistent with the intensity of hydrologic droughts. The periods of 1970s and 2010s exhibited the highest occurrence frequency. (3) The karst drainage basins in Southern China experienced extremely complex variability of hydrologic droughts from 1970s to 2010s. Drought intensity and occurrence frequency significantly vary for different types of hydrology.

  20. The Jiuxi basin, Hexi Corridor, NW China: foreland structural features and hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q.M. (JAPEX Geoscience Inst. Inc., Tokyo (Japan)); Coward, M.P. (Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Geology)

    1993-04-01

    The Jiuxi (Western Jiuquan) Basin, located in the west of the Hexi Corridor, NW China, is a foreland basin which has been active since the Early Jurassic. It was formed as a consequence of the progressive northwards migration of the North Qilian thrusts in response to sinistral shearing along the 2,000-km long Aerjin (Altun) Fault. Sedimentary deposits in the basin are controlled not only by foreland loading and thrusting, but also by the development of listric normal faults at high angles to the thrust belt. At the junctions of these two sets of faults, thick organic-rich sediments and reservoirs have accumulated. During the Tertiary and Quaternary, thrusts propagated along the foot-wall of the North Qilian Fault, truncating earlier-formed oil pools and source-rock layers and thereby causing great difficulties for petroleum exploration. A basin development model is proposed in this paper from an integrated study of sedimentary facies, drilling and seismic data, structural analyses and cross-section reconstructions. The average northwards movement in the frontal zone of the North Qilian Mountains since the Pliocene is estimated at about 8 mm/yr. Therefore, about one-half of the Jurassic-Cretaceous oil-bearing basin could be buried beneath the Laojunmiao and North Qilian Marginal Faults and is virtually untouched by drilling. Source rocks in the basin are black, lacustrine shales of Late Jurassic through Early Cretaceous ages, with a maximum thickness of up to 1.2 km in the Qingxi Depression. The generation of liquid hydrocarbons began in the Late Cretaceous or mid-Oligocene: seven stratigraphical reservoirs, ranging in age from Silurian to Miocene, are described - anticlinal, fault- and ''buriedhill'' structures are the most important traps. The petroleum potential of individual depressions is discussed, and suggestions for potential regional oil prospects are made. (author)

  1. Accumulation conditions of Lower Paleozoic shale gas from the southern Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Xianqing Li

    2016-04-01

    Full Text Available Based on the raw data of the organic-rich shale in the Lower Cambrian Qiongzhusi Formation and Lower Silurian Longmaxi Formation which were collected from the drilling core, we investigated the accumulation conditions of the Lower Paleozoic marine shale gas in the southern Sichuan Basin, China. The results indicate that the Qiongzhusi and the Longmaxi Formations' black shales in this region are mainly deposited in the deep water shelf sedimentary environment. Both the Qiongzhusi and Longmaxi Formations in the southern Sichuan Basin have great organic-rich shale thickness (mainly 50–300 m. The marine shales of the Qiongzhusi and the Longmaxi Formations are characterized by high total organic carbon contents (average TOC>2%, I–II1 kerogen types, highthermal maturity level (equivalent RO>1.9%, abundant rich brittle mineral (average > 50%, micro- and nanometer pore development, as well as high gas content of shale (average > 1.8 m3/t. All these features are favorable for marine shale gas generation and enrichment in the southern Sichuan Basin. Compared to the Barnett shale in North America, in which shale gas has been explored and developed successfully, it is suggested that the Lower Paleozoic in the southern Sichuan Basin would possess good conditions for shale gas accumulation. Therefore, the Qiongzhusi and the Longmaxi Formations are considered as potential targets for marine shale gas exploration, and favorable areas for shale gas enrichment are also purposed. The favorable areas for shale gas enrichment for the Qiongzhusi Formation in the southern Sichuan Basin are the Zhigong-Yibin, Changning-Gongxian, Jianwei-Muchuan, and Weiyuan areas. The favorable areas for shale gas enrichment for the Longmaxi Formation in the southern Sichuan Basin are the Longchang-Rongchang, Yibin-Luzhou-Changning, and Weiyuan areas.

  2. Model Prediction of Secondary Soil Salinization in the Keriya Oasis, Northwest China

    Directory of Open Access Journals (Sweden)

    Jumeniyaz Seydehmet

    2018-02-01

    Full Text Available Significant anthropogenic and biophysical changes have caused fluctuations in the soil salinization area of the Keriya Oasis in China. The Driver-Pressure-State-Impact-Response (DPSIR sustainability framework and Bayesian networks (BNs were used to integrate information from anthropogenic and natural systems to model the trend of secondary soil salinization. The developed model predicted that light salinization (vegetation coverage of around 15–20%, soil salt 5–10 g/kg of the ecotone will increase in the near term but decelerate slightly in the future, and that farmland salinization will decrease in the near term. This trend is expected to accelerate in the future. Both trends are attributed to decreased water logging, increased groundwater exploitation, and decreased ratio of evaporation/precipitation. In contrast, severe salinization (vegetation coverage of around 2%, soil salt ≥20 g/kg of the ecotone will increase in the near term. This trend will accelerate in the future because decreased river flow will reduce the flushing of severely salinized soil crust. Anthropogenic factors have negative impacts and natural causes have positive impacts on light salinization of ecotones. In situations involving severe farmland salinization, anthropogenic factors have persistent negative impacts.

  3. Prevalence, awareness, treatment and control of hypertension in Tibetan monks from Gansu Province, Northwest China.

    Science.gov (United States)

    Li, Xinghui; Cai, Hui; He, Jin; Ramachandran, Devasundaram; Xie, Ping; Huang, Yan; Wang, Hongjing; Liu, Yan; Qiao, Yan; Zhang, Qing

    2015-01-01

    Tibetan monks are a special group in life style and diet customs. We have little information of hypertension about them. Therefore, the objective of this study was to investigate the information on the prevalence, awareness, treatment and control of hypertension in these populations. A cross-sectional study of hypertension was carried out in 984 monks and 1042 Tibetan residents' controls in the same area. All the subjects were selected for interview, and physical examination involved blood pressure (BP) measurement. The overall prevalence of hypertension in monks was significantly lower than those in local residents (19.3% versus 34.1%; p monks were also lower than those in local residents (9.5% versus 16.9%, 4.2% versus 13.2% and 1.6% versus 4.5%; p monks aged 18 years and over in Gannan Tibetan autonomous district of Gansu province in China. We concluded that the relatively healthy diet and ways of life in monks were the major contributing factors to the lower prevalence of hypertension. However, the awareness, treatment and control rates of hypertension were also low. The possible reasons were most likely due to the difficult access to quality medical care and poor health education.

  4. Typical synoptic situations and their impacts on the wintertime air pollution in the Guanzhong basin, China

    Directory of Open Access Journals (Sweden)

    N. Bei

    2016-06-01

    Full Text Available Rapid industrialization and urbanization have caused severe air pollution in the Guanzhong basin, northwestern China, with heavy haze events occurring frequently in recent winters. Using the NCEP reanalysis data, the large-scale synoptic situations influencing the Guanzhong basin during wintertime of 2013 are categorized into six types to evaluate the contribution of synoptic situations to the air pollution, including “north-low”, “southwest-trough”, “southeast-high”, “transition”, “southeast-trough”, and “inland-high”. The FLEXPART model has been utilized to demonstrate the corresponding pollutant transport patterns for the typical synoptic situations in the basin. Except for “southwest-trough” and “southeast-high” (defined as favorable synoptic situations, the other four synoptic conditions (defined as unfavorable synoptic situations generally facilitate the accumulation of air pollutants, causing heavy air pollution in the basin. In association with the measurement of PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm in the basin, the unfavorable synoptic situations correspond to high PM2.5 mass concentrations or poor air quality and vice versa. The same analysis has also been applied to winters of 2008–2012, which shows that the basin was mainly influenced by the unfavorable synoptic situations during wintertime leading to poor air quality. The WRF-CHEM model has further been applied to simulate the selected 6 days representing the typical synoptic situations during the wintertime of 2013, and the results generally show a good agreement between the modeled distributions and variations of PM2.5 and the corresponding synoptic situations, demonstrating reasonable classification for the synoptic situations in the basin. Detailed meteorological conditions, such as temperature inversion, low-level horizontal wind speed, and planetary boundary layer, all contribute to heavy air pollution

  5. Patterns and Environmental Determinants of Medicinal Plant : Vascular Plant Ratios in Xinjiang, Northwest China

    Science.gov (United States)

    Zhang, Bengang; Xiao, Peigen; Qi, Yaodong; Zhang, Zhao; Liu, Haitao; Li, Xiaojin; Wang, Guoping; Terwei, André

    2016-01-01

    With both a full collection of native vascular plant distributions and a full checklist of source plants of the Chinese Materia Medica (CMM), the Uygur Medicine (UM), and the Kazak Medicine (KM) for the Xinjiang region, we defined medicinal plant: vascular plant ratios (simplified as medicinal plant ratios hereafter) as the value of medicinal plant richness divided by vascular plant richness. We aimed to find whether the ratios are constant or change in different environments, which environmental variables determine medicinal plant ratios, and whether the ratios are more influenced by human or by natural environments. Finally, suggestions for medicinal plant conservation were addressed. We found that (1) medicinal plant ratios were not constant, and they were high in the Tarim Basin which was largely covered by desert, while they were relatively low in mountainous areas, especially in the Tianshan Mountains where the general species richness was high; (2) medicinal plant ratios were not significantly influenced by human activities, indicated by human population density distributions, but they were highly correlated with plant species richness and climate, i.e. ratios decreased with plant species richness and MAP, and were related quadratically with MAT; (3) CMM ratio and UM ratio were more influenced by plant richness than by climate, while KM ratio was more influenced by climate. We concluded that the percentages of plants used as medicines were not influenced by distances from human settlements, but were determined by species richness or climate. We suggest that (1), in general, the medicinal plant ratio could be a complementary indicator for medicinal plant conservation planning and (2), for the region of Xinjiang, not only high diversity areas, but also some extreme environments should be considered as compensation for a better protection of medicinal plants. PMID:27391239

  6. Patterns and Environmental Determinants of Medicinal Plant : Vascular Plant Ratios in Xinjiang, Northwest China.

    Directory of Open Access Journals (Sweden)

    Liping Li

    Full Text Available With both a full collection of native vascular plant distributions and a full checklist of source plants of the Chinese Materia Medica (CMM, the Uygur Medicine (UM, and the Kazak Medicine (KM for the Xinjiang region, we defined medicinal plant: vascular plant ratios (simplified as medicinal plant ratios hereafter as the value of medicinal plant richness divided by vascular plant richness. We aimed to find whether the ratios are constant or change in different environments, which environmental variables determine medicinal plant ratios, and whether the ratios are more influenced by human or by natural environments. Finally, suggestions for medicinal plant conservation were addressed. We found that (1 medicinal plant ratios were not constant, and they were high in the Tarim Basin which was largely covered by desert, while they were relatively low in mountainous areas, especially in the Tianshan Mountains where the general species richness was high; (2 medicinal plant ratios were not significantly influenced by human activities, indicated by human population density distributions, but they were highly correlated with plant species richness and climate, i.e. ratios decreased with plant species richness and MAP, and were related quadratically with MAT; (3 CMM ratio and UM ratio were more influenced by plant richness than by climate, while KM ratio was more influenced by climate. We concluded that the percentages of plants used as medicines were not influenced by distances from human settlements, but were determined by species richness or climate. We suggest that (1, in general, the medicinal plant ratio could be a complementary indicator for medicinal plant conservation planning and (2, for the region of Xinjiang, not only high diversity areas, but also some extreme environments should be considered as compensation for a better protection of medicinal plants.

  7. [Ecosystem's soil conservation function and its spatial distribution in Lancang River Basin, Southwest China].

    Science.gov (United States)

    Chen, Long; Xie, Gao-Di; Pei, Sha; Zhang, Chang-Shun; Fan, Na; Zhang, Cai-Xia; Li, Shi-Mei

    2012-08-01

    Based on the RUSLE model, this paper analyzed the ecosystem's soil conservation function and its spatial distribution in Lancang River Basin. This Basin could be one of the regions having the highest ecosystem' s soil conservation capability in China, with an annual ecosystem's soil conservation amount being 2.36 x 10(10) t x a(-1) and the soil conservation amount per unit area being 1453.72 t x a(-1) per hectare. The total amounts of the N, P, and K conserved in soils were 5.74 x 10(7), 3.07 x 10(7), and 3.75 x 10(8) t x a(-1), respectively, and presented an increasing trend from upstream to downstream. Among the ecosystems in the Basin, forest ecosystem had the highest soil conservation capability, followed by grassland and farmland, while desert ecosystem had the lowest one. The soil conservation capability of the ecosystems was linearly increased with the increase of vegetation coverage. Averagely, a 10% increment in the vegetation coverage could result in a 35.3% increment in soil conservation capability. To rationally increase the vegetation coverage by reliable ecosystem management based on local conditions would make good effect in preventing soil erosion and maintaining soil nutrients in the Basin.

  8. Survey and discussion of history of prospecting in the oil and gas basin Tszyankhan. [China

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, S.

    1982-01-01

    A detailed description is made of the history of prospecting for oil and gas which started in the first half of the 1950's. The oil and gas basin Tszinkhan is located in the central part of Eastern China, and southwest of Ukhan. A large number of oil and gas reserves are confined to the mass of lake-saline deposits which were formed in the late Paleogene under conditions of isolated groove basins. The greatest part of the reserves is confined to the northern part of the asymmetrical basin Tszyantsyan. Accumulation of oil here was controlled by sandstones of alluvial fans (Tszyantsyan series) and saline-cupola structures associated with eddy tectonic systems (specific type of structure isolated by the Chinese geologists for which concentric arrangement of the structural axes is characteristic). This special type of trap was isolated for the first time in this oil and gas basin. Initially, until the role of sandy bodies in the ancient alluvial fans was established in controlling oil content, prospecting encountered great difficulties.

  9. Speciation, sources, and risk assessment of heavy metals in suburban vegetable garden soil in Xianyang City, Northwest China

    Science.gov (United States)

    Wang, Lijun; Tao, Wendong; Smardon, Richard C.; Xu, Xue; Lu, Xinwei

    2017-07-01

    Intensive anthropogenic activities can lead to soil heavy metal contamination resulting in potential risks to the environment and to human health. To reveal the concentrations, speciation, sources, pollution level, and ecological risk of heavy metals in vegetable garden soil, a total of 136 soil samples were collected from three vegetable production fields in the suburbs of Xianyang City, Northwest China. These samples were analyzed by inductively coupled plasma- atomic emission spectrometry and atomic fluorescence spectrometry. The results showed that the mean concentrations of Cd, Co, Cu, Mn, Pb, Zn, and Hg in vegetable garden soil were higher than the corresponding soil element background values of Shaanxi Province. The heavy metals studied in vegetable garden soil were primarily found in the residual fraction, averaging from 31.26% (Pb) to 90.23% (Cr). Considering the non-residual fractions, the mobility or potential risk was in the order of Pb (68.74%)>Co (60.54%)>Mn (59.28%) >Cd (53.54%) ≫Ni (23.36%) >Zn (22.73%)>Cu (14.93%)>V (11.81%)>Cr (9.78%). Cr, Mn, Ni, V, and As in the studied soil were related to soilforming parent materials, while Cu, Hg, Zn, Cd, Co, and Pb were associated with the application of plastic films, fertilizers, and pesticides, as well as traffic emissions and industrial fumes. Cr, Ni, V, and As presented low contamination levels, whereas Co, Cu, Mn, Pb, and Zn levels were moderate, and Cd and Hg were high. Ecological risk was low for Co, Cr, Cu, Mn, Pb, Zn, and As, with high risk observed for Cd and Hg. The overall pollution level and ecological risk of these heavy metals were high.

  10. [Effects of different drip irrigation modes on root distribution of wine grape 'Cabernet Sauvignon' in desert area of Northwest China].

    Science.gov (United States)

    Mao, Juan; Chen, Bai-Hong; Cao, Jian-Dong; Wang, Li-Jun; Wang, Hai; Wang, Yan-Xiu

    2013-11-01

    To study the effects of different drip irrigation modes on the wine grape root distribution is the basis of formulating fertilization, irrigation, and over-wintering management practices for wine grape. Taking the wine grape "Cabernet Sauvignon" as test material, this paper studied the effects of different water-saving irrigation modes (drip irrigation under straw mulching, drip irrigation under plastic mulching, double-tube drip irrigation, and single-tube drip irrigation) on the root distribution of wine grape in the desert area of Northwest China, with the conventional furrow irrigation as the control. The root system of the "Cabernet Sauvignon" was distributed from 0 to 70 cm vertically, and from 0 to 120 cm horizontally. With double-tube drip irrigation, the root amount was the largest (138.3 roots per unit profile), but the root vertical distribution scope was narrowed by 20 cm, as compared to the control. Drip irrigation with straw mulching increased the root amount significantly, and increased the root horizontal distribution scope by 9.1%, as compared to the control. No significant difference was observed in the root number and root horizontal distribution scope between the drip irrigation under plastic mulching and the control, but the root vertical distribution scope with the drip irrigation under plastic mulching decreased by 20 cm. Single-tube drip irrigation increased the root number significantly, but had lesser effects on the root vertical or horizontal distribution, as compared to the conventional irrigation. It was suggested that the drip irrigation under straw mulching could be the best water-saving practice for the wine grape "Cabernet Sauvignon" in the study area.

  11. Multiscale evolution of surface air temperature in the arid region of Northwest China and its linkages to ocean oscillations

    Science.gov (United States)

    Chen, Zhongsheng; Chen, Yaning; Bai, Ling; Xu, Jianhua

    2017-05-01

    The global climate has experienced unprecedented warming in the past century. The multiscale evolution of the warming is studied to better understand the spatial and temporal variation patterns of temperature. In this study, based on the yearly surface air temperature from the gridded CRU TS 3.22 dataset and the ensemble empirical mode decomposition method (EEMD), we investigated the multiscale evolution of temperature variability in the arid region of Northwest China (ARNC) from 1901 to 2013. Furthermore, the possible influences on the ARNC temperature change from the Atlantic Multidecadal Oscillation (AMO), Pacific Decadal Oscillation (PDO), and dipole mode index (DMI) were also discussed. The results indicated that in the past century, the overall temperature in the ARNC has showed a significant non-linear upward trend, and its changes have clearly exhibited an interannual scale (quasi-2-3 and quasi-6-7-year) and an interdecadal scale (quasi-14, quasi-24, and quasi-70-year). Compared with the reconstructed interannual variation, the reconstructed interdecadal variability plays a decisive role in the ARNC warming and reveals the climatic pattern transformation from the cold period to the warm period before and after 1987. Additionally, there were also regional differences in the spatial patterns of change trend in the ARNC temperature at a given time. We also found that the AMO and PDO had significant impacts on the ARNC temperature fluctuation at an interdecadal scale, whereas the DMI had a more important role in warming at the annual scale, which suggests that the importance of oceans cannot be ignored when considering climate change. Our findings deepen the understanding of the temperature changes all over the ARNC in the context of global warming.

  12. Spatiotemporal Variation of Karst Ecosystem Service Values and Its Correlation with Environmental Factors in Northwest Guangxi, China

    Science.gov (United States)

    Zhang, Mingyang; Zhang, Chunhua; Wang, Kelin; Yue, Yuemin; Qi, Xiangkun; Fan, Feide

    2011-11-01

    In this investigation we analyzed the spatiotemporal variation of ecosystem service values (ESVs) and its correlation with numerous environmental factors (EFs) for the karst region of Northwest Guangxi, China, from 1985 to 2005 using remote sensing, geographic information systems (GIS) and statistical techniques. The results indicate that historically ESVs for this karst region decreased from 1985 (109.652 billion Yuan) to 1990 (88.789 billion Yuan) and then increased at the turn of the twenty-first century. However, the ESVs in both 2000 (103.384 billion Yuan) and 2005 (106.257 billion Yuan) never achieved the level recorded in 1985. The total of nutrient cycling, organic production and gas regulation combined were 72.69, 64.57, 70.18 and 72.10% of ESVs in 1985, 1990, 2000 and 2005, respectively. In contrast, the ESVs of water conservation, soil reservation, recreation and culture were determined to be relatively low contributing only 17.44, 23.82, 19.26 and 24.76% of total ESVs, respectively, during these four years. With regards to the spatial distribution of ESVs, larger values were recorded in the west and smaller ones recorded in the east. The most significant factors that were deemed to influence ESVs are annual rainfall, per capita cropland, slope and vegetation coverage. Annual rainfall and slope exert a negative force, whereas per capita cropland and vegetation coverage exert a positive force on ESVs. The results of the study would suggest that ecosystem conditions of this important karst region have been improved as the result of the implementation of rocky desertification control policies.

  13. Quantitative analysis of burden of infectious diarrhea associated with floods in northwest of anhui province, china: a mixed method evaluation.

    Science.gov (United States)

    Ding, Guoyong; Zhang, Ying; Gao, Lu; Ma, Wei; Li, Xiujun; Liu, Jing; Liu, Qiyong; Jiang, Baofa

    2013-01-01

    Persistent and heavy rainfall in the upper and middle Huaihe River of China brought about severe floods during the end of June and July 2007. However, there has been no assessment on the association between the floods and infectious diarrhea. This study aimed to quantify the impact of the floods in 2007 on the burden of disease due to infectious diarrhea in northwest of Anhui Province. A time-stratified case-crossover analysis was firstly conducted to examine the relationship between daily cases of infectious diarrhea and the 2007 floods in Fuyang and Bozhou of Anhui Province. Odds ratios (ORs) of the flood risk were quantified by conditional logistic regression. The years lived with disability (YLDs) of infectious diarrhea attributable to floods were then estimated based on the WHO framework of the calculating potential impact fraction in the Burden of Disease study. A total of 197 infectious diarrheas were notified during the exposure and control periods in the two study areas. The strongest effect was shown with a 2-day lag in Fuyang and a 5-day lag in Bozhou. Multivariable analysis showed that floods were significantly associated with an increased risk of the number cases of infectious diarrhea (OR = 3.175, 95%CI: 1.126-8.954 in Fuyang; OR = 6.754, 95%CI: 1.954-23.344 in Bozhou). Attributable YLD per 1000 of infectious diarrhea resulting from the floods was 0.0081 in Fuyang and 0.0209 in Bozhou. Our findings confirm that floods have significantly increased the risks of infectious diarrhea in the study areas. In addition, prolonged moderate flood may cause more burdens of infectious diarrheas than severe flood with a shorter duration. More attention should be paid to particular vulnerable groups, including younger children and elderly, in developing public health preparation and intervention programs. Findings have significant implications for developing strategies to prevent and reduce health impact of floods.

  14. Carbon balance of a plastic mulch and drip irrigated cotton field in an arid oasis of Northwest China

    Science.gov (United States)

    Ming, G.

    2017-12-01

    Carbon balance of a plastic mulch and drip irrigated cotton field in an arid oasis of Northwest ChinaGuanghui Ming1, Fuqiang Tian1*, Hongchang Hu11State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing, China,Abstracts: Agricultural ecosystems have the potential to offset rising CO2 concentration in the atmosphere but the potential is often altered by agricultural management. Plastic film mulching and drip irrigation (PMDI) have been widespread for saving water and improving crop yield worldwide. To comprehensively assess the carbon balance and to detect the controlling factors of the carbon flux in a PMDI cotton field, experiments combining eddy covariance (EC) system, chamber method and crop sampling were implemented in an arid oasis of Xinjiang from the year 2012 to 2016. The annual net ecosystem exchange (NEE) was -250.18 ± 80.41 g C m-2 in the five years, which indicated that the filed was a much stronger carbon sink. After removal of the harvest of cotton as seed oil (Ch) of 108.81±7.57 g C m-2, the field was still a moderate carbon sink with net biome productivity (NBP) of 141.37±73.7 g C m-2. Soil temperature can explain 82% of seasonal variation of nighttime NEE while PAR can explain 36-81% of daytime NEE varying with crop development and photosynthetic activity. NEE was separated into total ecosystem respiration (Reco, 1214.20±144.42 g C m-2) and gross primary productivity (GPP, 1464.38±122.78 g C m-2). Interannual Reco changed more drastically than GPP and respiration may be the main determinant of carbon balance in the PMDI field. Seasonal NPP measured by cop sampling method (NPPCS) agreed well with NPP calculated with EC (NPPEC), with the annual NPP of 708.86 ± 52.26 g C m-2, which indicated that our carbon flux measurements and separating methods reasonable. The PMDI cotton field induced more GPP and Reco than other croplands with larger light use efficiency (LUE) but relatively

  15. Coal fires in Northwest China. Detection, monitoring, and prediction using remote sensing data

    International Nuclear Information System (INIS)

    Zhang, Xiangmin

    1998-01-01

    Coal fires in China occur within a region that stretches over 5,000 km in the east- western part and 750 km. in the north-southern part. These fires cause an economic and environmental threat by making a significant contribution to the global CO2 budget. The studies made in this thesis can be divided into two parts. Part one is based on field work and laboratory analysis that includes the dating of the paleo coal fires; part two concerns remote sensing applications for the active coal fires. In Chapter 2, the evolution of the paleo coal fires in Toutunhe and Xinjiang areas are studied. Several age groups of burnt rock have been recognized and their relationships with the river terraces will be discussed. The causes of the paleo coal fires are addressed, and the areas of coal fires with different ages have been dated. In Chapter 3, the physical basis of thermal infrared remote sensing for the detection and measurement of coal fires are addressed with an emphasis on the spatial, spectral, and radiometric resolution. In Chapter 4, a method to reduce the effect of solar heating, the main factor of confusion when investigating the thermal anomalies of coal fires, is discussed with the help of a DEM. In Chapter 5, as the coal fires normally occupy only part of one pixel of the Landsat TM thermal channel data, the capability of sub pixel coal fire detection is addressed. In Chapter 6, the airborne data from different wavelengths acquired at different times are studied to analyze the spatial thermal characteristics of the coal fires. Spreading direction and different types of coal fires are studied. Chapter 7 presents, based on multi-sensor data fusion techniques, a hierarchical methodology for detection and monitoring of the coal fires. 120 refs

  16. Spectral Exploration of Calcium Accumulation in Organic Matter in Gray Desert Soil from Northwest China.

    Science.gov (United States)

    Wang, Ping; Ma, Yucui; Wang, Xihe; Jiang, Hong; Liu, Hua; Ran, Wei; Shen, Qirong

    2016-01-01

    Little attention has been paid to the accumulation of soil organic matter (SOM) in the fringes of the mid-latitude desert. In this paper, soil samples from a long-term field experiment conducted from 1990 to 2013 at a research station in Urumqi, China by different fertilizer treatments, were used to determine soil properties and soil dissolved organic matter (DOM) by chemical analysis, fluorescence excitation emission matrix (EEM) spectroscopy, and high resolution-transmission electron microscopy (HR-TEM). The binding features of DOM under the addition of Ca(2+) were analyzed using a two-dimensional (2D) Fourier transform infrared (FTIR) spectrometer further to explore the response of the DOM to increasing concentrations of Ca(2+). Long-term application of chemical fertilizers and goat manure increased soil organic carbon (SOC) by 1.34- and 1.86-fold, respectively, relative to the non-fertilized control (8.95 g.kg(-1)). Compared with the control, application of chemical fertilizers and manure significantly increased the concentrations of Ca, Mg, Si, humic and fulvic acid-like substances in DOM but decreased the amounts of trivalent metals (Al and Fe) and protein-like substances. Although crystalline Al/Fe nanoparticles and amorphous or short-range-order Si/Al nanoparticles existed in all DOM samples, crystalline Ca/Si nanoparticles were predominant in the samples treated with goat manure. Although organic matter and Si-O-containing nanoparticles were involved in the binding of Ca(2+) to DOM, application of chemical fertilizers weakened Ca(2+) association with components of the amide II group (1510 cm(-1)) and Si-O linkage (1080 cm(-1)), whereas application of goat manure enhanced the affinity of Ca(2+) for Si-O linkage. Our results suggested that the enrichment of Ca in gray desert soil possibly helps accumulate SOM by forming crystalline Ca/Si nanoparticles in addition to Ca(2+) and organic matter complexes.

  17. Meso–Cenozoic lithospheric thermal structure in the Bohai Bay Basin, eastern North China Craton

    Directory of Open Access Journals (Sweden)

    Zongxing Li

    2017-09-01

    Full Text Available The Bohai Bay Basin is a region where part of the North China Craton has been thinned and destroyed. It has experienced two periods of crustal thinning that occurred during the Cretaceous and Paleogene, but investigations of its Mesozoic and Cenozoic lithospheric thermal structure are limited. Therefore, in this study, the distributions of mantle heat flow, crustal heat flow, and Moho temperatures during the Meso–Cenozoic are calculated based on analyses of the thermal history of the Bohai Bay Basin. The results indicate that the ratio of mantle heat flow to surface heat flow peaked during the late stages of the early Cretaceous and during the middle to late Paleogene. The corresponding mantle heat flow was more than 65% of the surface heat flow. Moho temperatures reached three peaks: 900–1100 °C in the late stages of the early Cretaceous; 820–900 °C in the middle to late Paleogene; and (in the Linqing Depression, Cangxian Uplift, and Jizhong Depression 770–810 °C during the early Neogene. These results reveal that the Bohai Bay Basin experienced significant geological change during the Cretaceous, including the transformation of lithospheric thermal structure from “cold mantle and hot crust” before the Cretaceous to “hot mantle and cold crust” after the Cretaceous. The results also indicate that the basin experienced two large-scale rifting events. Therefore, this work may provide the thermal parameters for further investigations of the geodynamic evolution of eastern China.

  18. High-Resolution Magnetic Susceptibility Stratigraphy Spanning Late Devonian Global Change from a New Scientific Drillcore in Canning Basin, Northwest Australia

    Science.gov (United States)

    Diamond, M. R.; Raub, T. D.; Kirschvink, J. L.; Playton, T. E.; Hocking, R. M.; Haines, P.; Tulipani, S.

    2010-12-01

    New shallow scientific drillcore has been recovered through the Frasnian-Famennian extinction boundary in northwest Australia’s Canning Basin. Previous work in the McWhae Ridge outcrop belt has identified patterns of turnover in trilobites and other fauna, change from sponge- and coral-dominated reefs to post-extinction microbial-dominated reefs, apparent sea level changes, and carbon isotopic evidence of late Devonian crisis. Continuous magnetic susceptibility (MS) stratigraphy yields highly structured oscillations spanning ~42 m of reef-slope carbonate. These oscillations appear to identify late Frasnian “Kellwasser” events and they may record sedimentary response to orbital variations, establishing a high-resolution relative chronostratigraphy of late Devonian global change. Magnetic susceptibility stratigraphy has been proposed as a generally useful chronometer for late Devonian time. Most of fifteen published MS stratigraphies crossing the Frasnian-Famennian boundary appear to share major excursions with the new McWhae Ridge result. Although upland tectonism in Canning Basin may be a caveat to straightforward eustatic interpretation of magnetic susceptibility variations, we suggest the higher-resolution and fresh drillcore context of this result prioritizes it as a standard for Frasnian-Famennian magnetic susceptibility variation.

  19. Lower crustal earthquakes in the North China Basin and implications for crustal rheology

    Science.gov (United States)

    Yuen, D. A.; Dong, Y.; Ni, S.; LI, Z.

    2017-12-01

    The North China Basin is a Mesozoic-Cenozoic continental rift basin on the eastern North China Craton. It is the central region of craton destruction, also a very seismically active area suffering severely from devastating earthquakes, such as the 1966 Xingtai M7.2 earthquake, the 1967 Hejian M6.3 earthquake, and the 1976 Tangshan M7.8 earthquake. We found remarkable discrepancies of depth distribution among the three earthquakes, for instance, the Xingtai and Tangshan earthquakes are both upper-crustal earthquakes occurring between 9 and 15 km on depth, but the depth of the Hejian earthquake was reported of about 30 72 km, ranging from lowermost crust to upper mantle. In order to investigate the focal depth of earthquakes near Hejian area, we developed a method to resolve focal depth for local earthquakes occurring beneath sedimentary regions by P and S converted waves. With this method, we obtained well-resolved depths of 44 local events with magnitudes between M1.0 and M3.0 during 2008 to 2016 at the Hejian seismic zone, with a mean depth uncertainty of about 2 km. The depth distribution shows abundant earthquakes at depth of 20 km, with some events in the lower crust, but absence of seismicity deeper than 25 km. In particular, we aimed at deducing some constraints on the local crustal rheology from depth-frequency distribution. Therefore, we performed a comparison between the depth-frequency distribution and the crustal strength envelop, and found a good fit between the depth profile in the Hejian seismic zone and the yield strength envelop in the Baikal Rift Systems. As a conclusion, we infer that the seismogenic thickness is 25 km and the main deformation mechanism is brittle fracture in the North China Basin . And we made two hypotheses: (1) the rheological layering of dominant rheology in the North China Basin is similar to that of the Baikal Rift Systems, which can be explained with a quartz rheology at 0 10 km depth and a diabase rheology at 10 35 km

  20. Mesozoic to Cenozoic tectonic transition process in Zhanhua Sag, Bohai Bay Basin, East China

    Science.gov (United States)

    Cheng, Yanjun; Wu, Zhiping; Lu, Shunan; Li, Xu; Lin, Chengyan; Huang, Zheng; Su, Wen; Jiang, Chao; Wang, Shouye

    2018-04-01

    The Zhanhua sag is part of the Bohai Bay intracontinental basin system that has developed since the Mesozoic in East China. The timing of this basin system coincides with the final assembly of East Asia and the development of Western Pacific-type plate margin. Here we use 3-D seismic and core log data to investigate the evolution of this basin and discuss its broad tectonic settings. Our new structural study of Zhanhua sag suggests that there are four major tectonic transitions occurred in the Bohai Bay Basin during Mesozoic and Cenozoic: (1) The first tectonic transition was from stable Craton to thrusting during the Triassic, mainly caused by the South China Block's subduction northward beneath the North China Block, which induced the formation of the NW-striking thrust faults. (2) The second tectonic transition was mainly characterized by a change from compression to extension, which can be further divided into two-stages. At the first stage, two episodes of NW-SE shortening occurred in East Asia during Early-Middle Jurassic and Late Jurassic-earliest Cretaceous, respectively. At the second stage, the extension and left-lateral shearing took place during Early Cretaceous while compression occurred during Late Cretaceous. The NW-striking thrust faults changed to normal faults and the NNE-striking left-lateral strike-slip faults started to influence the eastern part of the basin. (3) The third transition occurred when the NW-SE extension and NNE-striking right-lateral shearing started to form during Paleogene, and the peak deformation happen around 40 Ma due to the change of the subduction direction of Pacific Plate relative to Eurasia Plate. The NE-striking normal faults are the main structure, and the pre-existing NNE-striking strike-slip faults changed from left-lateral to right-lateral. (4) The fourth transition saw the regional subsidence during Neogene, which was probably caused by the India-Asia "Hard collision" between 25 and 20 Ma.

  1. Multimedia fate modeling and risk assessment of a commonly used azole fungicide climbazole at the river basin scale in China.

    Science.gov (United States)

    Zhang, Qian-Qian; Ying, Guang-Guo; Chen, Zhi-Feng; Liu, You-Sheng; Liu, Wang-Rong; Zhao, Jian-Liang

    2015-07-01

    Climbazole is an antidandruff active ingredient commonly used in personal care products, but little is known about its environmental fate. The aim of this study was to evaluate the fate of climbazole in water, sediment, soil and air compartments of the whole China by using a level III multimedia fugacity model. The usage of climbazole was calculated to be 345 t in the whole China according to the market research data, and after wastewater treatment a total emission of 245 t was discharged into the receiving environment with approximately 93% into the water compartment and 7% into the soil compartment. The developed fugacity model was successfully applied to estimate the contamination levels and mass inventories of climbazole in various environmental compartments of the river basins in China. The predicted environmental concentration ranges of climbazole were: 0.20-367 ng/L in water, and 0.009-25.2 ng/g dry weight in sediment. The highest concentration was mainly found in Haihe River basin and the lowest was in basins of Tibet and Xinjiang regions. The mass inventory of climbazole in the whole China was estimated to be 294 t, with 6.79% in water, 83.7% in sediment, 9.49% in soil, and 0.002% in air. Preliminary risk assessment showed high risks in sediment posed by climbazole in 2 out of 58 basins in China. The medium risks in water and sediment were mostly concentrated in north China. To the best of our knowledge, it is the first report on the emissions and multimedia fate of climbazole in the river basins of the whole China. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. The current strain distribution in the North China Basin of eastern China by least-squares collocation

    Science.gov (United States)

    Wu, J. C.; Tang, H. W.; Chen, Y. Q.; Li, Y. X.

    2006-07-01

    In this paper, the velocities of 154 stations obtained in 2001 and 2003 GPS survey campaigns are applied to formulate a continuous velocity field by the least-squares collocation method. The strain rate field obtained by the least-squares collocation method shows more clear deformation patterns than that of the conventional discrete triangle method. The significant deformation zones obtained are mainly located in three places, to the north of Tangshan, between Tianjing and Shijiazhuang, and to the north of Datong, which agree with the places of the Holocene active deformation zones obtained by geological investigations. The maximum shear strain rate is located at latitude 38.6°N and longitude 116.8°E, with a magnitude of 0.13 ppm/a. The strain rate field obtained can be used for earthquake prediction research in the North China Basin.

  3. Stationarity of annual flood peaks during 1951-2010 in the Pearl River basin, China

    Science.gov (United States)

    Zhang, Qiang; Gu, Xihui; Singh, Vijay P.; Xiao, Mingzhong; Xu, Chong-Yu

    2014-11-01

    The assumption of stationarity of annual peak flood (APF) records at 28 hydrological stations across the Pearl River basin, China, is tested. Abrupt changes in mean and variance are tested using the Pettitt technique and the Loess method. Trends of APFs are analyzed using the Mann-Kendall method and the Spearman technique. And then the stationarity of the APF series is further investigated by GAMLSS models and long-term persistence. Results indicate that: (1) abrupt changes in mean and variance have similar influences on the changing properties of APFs, such as stationarity. Abrupt changes in mean and variance are only field significant in the East River basin; (2) the change points have a considerable impact on the detection of trends, and these may be attributed to the fact that a abrupt increase or decrease in mean values will affect the trend variations. Besides, for the APF series being free of change points and trend, the GAMLSS models also corroborate stationarity of the APF series; (3) the nonstationarity in the Pearl River basin is mainly due to the existence of the change point. However, the APF series with change points in mean and/or variance are also characterized by long-term persistence, and thus it is infeasible to assert that the abrupt behaviors and/or trends of the APF series are the result of human activities or long-term persistence, especially in the East River basin. Results of this study will provide information for management of water resources and design of hydraulic facilities in the Pearl River basin in a changing environment.

  4. Assessing river water quality using water quality index in Lake Taihu Basin, China.

    Science.gov (United States)

    Wu, Zhaoshi; Wang, Xiaolong; Chen, Yuwei; Cai, Yongjiu; Deng, Jiancai

    2018-01-15

    Lake Taihu Basin, one of the most developed regions in China, has received considerable attention due to its severe pollution. Our study provides a clear understanding of the water quality in the rivers of Lake Taihu Basin based on basin-scale monitoring and a water quality index (WQI) method. From September 2014 to January 2016, four samplings across four seasons were conducted at 96 sites along main rivers. Fifteen parameters, including water temperature, pH, dissolved oxygen (DO), conductivity, turbidity (tur), permanganate index (COD Mn ), total nitrogen, total phosphorus, ammonium (NH 4 -N), nitrite, nitrate (NO 3 -N), calcium, magnesium, chloride, and sulfate, were measured to calculate the WQI. The average WQI value during our study period was 59.33; consequently, the water quality was considered as generally "moderate". Significant differences in WQI values were detected among the 6 river systems, with better water quality in the Tiaoxi and Nanhe systems. The water quality presented distinct seasonal variation, with the highest WQI values in autumn, followed by spring and summer, and the lowest values in winter. The minimum WQI (WQI min ), which was developed based on a stepwise linear regression analysis, consisted of five parameters: NH 4 -N, COD Mn , NO 3 -N, DO, and tur. The model exhibited excellent performance in representing the water quality in Lake Taihu Basin, especially when weights were fully considered. Our results are beneficial for water quality management and could be used for rapid and low-cost water quality evaluation in Lake Taihu Basin. Additionally, we suggest that weights of environmental parameters should be fully considered in water quality assessments when using the WQI min method. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. The Status of Vitamin B12 and Folate among Chinese Women: A Population-Based Cross-Sectional Study in Northwest China

    Science.gov (United States)

    Dang, Shaonong; Yan, Hong; Zeng, Lingxia; Wang, Quanli; Li, Qiang; Xiao, Shengbin; Fan, Xiaojing

    2014-01-01

    Objective To assess the status of the vitamin B12 and folate of Chinese women living in northwest China. Methods A population-based cross-sectional study was conducted in 2008 among Chinese women aged 10–49 years living in Shaanxi province of northwest China. A stratified multistage random sampling method was adopted to obtain a sample of 1170 women. The women were interviewed for collection of their background information and their plasma vitamin B12 and folate were measured with the immunoassay method. The status of both vitamins was evaluated and the prevalence of deficiency was estimated. Results The median value of the women was 214.5 pg/mL for vitamin B12 and 4.6 ng/mL for folate. The urban women had a significantly higher vitamin B12 (254.1 vs. 195.9 pg/mL) but lower folate (4.4 vs. 4.7 ng/mL) than rural women. Total prevalence of deficiency was 45.5% (95% CI: 42.6%∼48.4%) for vitamin B12 and 14.7% (95% CI: 12.6%∼16.8%) for folate. About 36% of women presented vitamin B12 deficiency alone, 5.2% belonged to folate deficiency alone and 9.5% was combined deficiency in both vitamins. More than 25% of the women were in marginal vitamin B12 status (200–299 pg/mL) and 60% in marginal status of folate (3–6 ng/mL). About 75.2% of rural women with folate deficiency were deficient in vitamin B12 and 46% for urban women. Quantile regression model found decreasing coefficient of folate status across 73 different quantiles of vitamin B12, which indicated that the women with folate deficiency had lower vitamin B12 significantly compared with those with no deficiency. Conclusions The deficiency of vitamin B12 and folate is still prevalent among the Chinese women in northwest China. Vitamin B12 deficiency could be more serious and the improvement of poor vitamin B12 status should be invoked when practicing the supplementation of folate against the neural tube defects in northwest China. PMID:25390898

  6. Spatial and temporal characteristics of droughts in Luanhe River basin, China

    Science.gov (United States)

    Wang, Yixuan; Zhang, Ting; Chen, Xu; Li, Jianzhu; Feng, Ping

    2018-02-01

    The spatial and temporal characteristics of drought are investigated for Luanhe River basin, using monthly precipitation data from 26 stations covering the common period of 1958-2011. The spatial pattern of drought was assessed by applying principal component analysis (PCA) to the Standardized Precipitation Index (SPI) computed on 3- and 12-month time scales. In addition, annual SPI and seasonal SPIs (including spring SPI, summer SPI, autumn SPI, and winter SPI) were also defined and considered in this study to characterize seasonal and annual drought conditions, respectively. For all seven SPI cases, three distinctive sub-regions with different temporal evolutions of droughts are well identified, respectively, representing the southeast, middle, and northwest of the Luanhe River basin. The Mann-Kendall (MK) trend test with a trend-free pre-whitening (TFPW) procedure and Sen's method were used to determine the temporal trends in the annual and seasonal SPI time series. The continuous wavelet transform (CWT) was employed for further detecting the periodical features of drought condition in each sub-region. Results of MK and Sen's tests show a general tendency of intensification in summer drought over the entire basin, while a significant mitigating trend in spring drought. On the whole, an aggravating trend of inter-annual drought is discovered across the basin. Based on the CWT, the drought variability in the basin is generally dominated by 16- to 64-month cycles, and the 2- to 6-year cycles appear to be obvious when concerned with annual and seasonal droughts. Furthermore, a cross wavelet analysis was performed to examine the possible links between the drought conditions and large-scale climate patterns. The teleconnections of ENSO, NAO, PDO, and AMO show significant influences on the regional droughts principally concentrated in the 16- to 64-month period, maybe responsible for the physical causes of the cyclical behavior of drought occurrences. PDO and AMO also

  7. Hydrochemical characterization and pollution sources identification of groundwater in Salawusu aquifer system of Ordos Basin, China.

    Science.gov (United States)

    Yang, Qingchun; Wang, Luchen; Ma, Hongyun; Yu, Kun; Martín, Jordi Delgado

    2016-09-01

    Ordos Basin is located in an arid and semi-arid region of northwestern China, which is the most important energy source bases in China. Salawusu Formation (Q3 s) is one of the most important aquifer systems of Ordos Basin, which is adjacent to Jurassic coalfield areas. A large-scale exploitation of Jurassic coal resources over ten years results in series of influences to the coal minerals, such as exposed to the oxidation process and dissolution into the groundwater due to the precipitation infiltration. Therefore, how these processes impact groundwater quality is of great concerns. In this paper, the descriptive statistical method, Piper trilinear diagram, ratios of major ions and canonical correspondence analysis are employed to investigate the hydrochemical evolution, determine the possible sources of pollution processes, and assess the controls on groundwater compositions using the monitored data in 2004 and 2014 (before and after large-scale coal mining). Results showed that long-term exploration of coal resources do not result in serious groundwater pollution. The hydrochemical types changed from HCO3(-)-CO3(2-) facies to SO4(2-)-Cl facies during 10 years. Groundwater hardness, nitrate and sulfate pollution were identified in 2014, which was most likely caused by agricultural activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Progressive Seismic Failure, Seismic Gap, and Great Seismic Risk across the Densely Populated North China Basin

    Science.gov (United States)

    Yin, A.; Yu, X.; Shen, Z.

    2014-12-01

    Although the seismically active North China basin has the most complete written records of pre-instrumentation earthquakes in the world, this information has not been fully utilized for assessing potential earthquake hazards of this densely populated region that hosts ~200 million people. In this study, we use the historical records to document the earthquake migration pattern and the existence of a 180-km seismic gap along the 600-km long right-slip Tangshan-Hejian-Cixian (THC) fault zone that cuts across the North China basin. The newly recognized seismic gap, which is centered at Tianjin with a population of 11 million people and ~120 km from Beijing (22 million people) and Tangshan (7 million people), has not been ruptured in the past 1000 years by M≥6 earthquakes. The seismic migration pattern in the past millennium suggests that the epicenters of major earthquakes have shifted towards this seismic gap along the THC fault, which implies that the 180- km gap could be the site of the next great earthquake with M≈7.6 if it is ruptured by a single event. Alternatively, the seismic gap may be explained by aseismic creeping or seismic strain transfer between active faults.

  9. Assessing the evolution of oases in arid regions by reconstructing their historic spatio-temporal distribution: a case study of the Heihe River Basin, China

    Science.gov (United States)

    Xie, Yaowen; Wang, Guisheng; Wang, Xueqiang; Fan, Peilei

    2017-12-01

    Oasis evolution, one of the most obvious surface processes in arid regions, affects various aspects of the regional environment, such as hydrological processes, ecological conditions, and microclimates. In this paper, the historical spatio-temporal evolution of the cultivated oases in the Heihe River Basin, the second largest inland watershed in the northwest of China, was assessed using multidisciplinary methods and data from multiple sources, including historical literature, ancient sites, maps and remotely sensed images. The findings show that cultivated oases were first developed on a large scale during the Han Dynasty (121 BC-220) and then gradually decreased in extent from the Six Dynasties period (220-581) to the Sui-Tang period (581-907), reaching a minimum in the Song-Yuan period (960-1368). An abrupt revival occurred during the Ming Dynasty (1368-1644) and continued through the Qing Dynasty (1644-1911), and during the period of the Republic of China (1912-1949), oasis development reached its greatest peak of the entire historical period. The oasis areas during seven major historical periods, i.e., Han, Six Dynasties, Sui-Tang, Song-Yuan, Ming, Qing, and Republic of China, are estimated to have been 1703 km2, 1115 km2, 629 km2, 614 km2, 964 km2, 1205 km2, and 1917 km2, respectively. The spatial distribution generally exhibited a continuous sprawl process, with the center of the oases moving gradually from the downstream region to the middle and even upstream regions. The oases along the main river remained stable during most periods, whereas those close to the terminal reaches were subject to frequent variations and even abandonment. Socio-economic factors were the main forces driving the evolution of cultivated oases in the area; among them, political and societal stability, national defense, agricultural policy, population, and technological progress were the most important.

  10. Hydrogeochemistry of high-fluoride groundwater at Yuncheng Basin, northern China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chengcheng [State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Gao, Xubo, E-mail: xubo.gao.cug@gmail.com [State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); University of Texas at Austin, Austin, TX, 78705 (United States); Wang, Yanxin, E-mail: yx.wang@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China)

    2015-03-01

    Hydrogeochemical and environmental isotope methods were integrated to delineate the spatial distribution and enrichment of fluoride in groundwater at Yuncheng Basin in northern China. One hundred groundwater samples and 10 Quaternary sediment samples were collected from the Basin. Over 69% of the shallow groundwater (with a F{sup −} concentration of up to 14.1 mg/L), 44% of groundwater samples from the intermediate and 31% from the deep aquifers had F{sup −} concentrations above the WHO provisional drinking water guideline of 1.5 mg/L. Groundwater with high F{sup −} concentrations displayed a distinctive major ion chemistry: Na-rich and Ca-poor with a high pH value and high HCO{sub 3}{sup −} content. Hydrochemical diagrams and profiles and hydrogen and oxygen isotope compositions indicate that variations in the major ion chemistry and pH are controlled by mineral dissolution, cation exchange and evaporation in the aquifer systems, which are important for F{sup −} mobilization as well. Leakage of shallow groundwater and/or evaporite (gypsum and mirabilite) dissolution may be the major sources for F{sup −} in groundwater of the intermediate and deep aquifers. - Highlights: • High-F{sup −} groundwater widely occurs in Yuncheng Basin of northern China. • High-F{sup −} groundwater is Na and HCO{sub 3}-rich and Ca-poor, with high pH. • Major hydrogeochemical processes are mineral dissolution, ion exchange and evaporation. • Shallow groundwater leakage/evaporite dissolution may cause F enrichment in lower aquifers.

  11. Water resources: the prerequisite for ecological restoration of rivers in the Hai River Basin, northern China.

    Science.gov (United States)

    Tang, Wenzhong; Mao, Zhanpo; Zhang, Hong; Shan, Baoqing; Zhao, Yu; Ding, Yuekui

    2015-01-01

    The competition for water resources between humans and river ecosystems is becoming ever more intense worldwide, especially in developing countries. In China, with rapid socioeconomic development, water resources to maintain river ecosystems are progressively decreasing, especially in the Hai River Basin (HRB), which has attracted much attention from the Chinese government. In the past 56 years, water resources have continuously decreased in the basin, such that there is 54.2 % less surface water now compared with then. Water shortages, mainly due to local anthropogenic activities, have emerged as the main limiting factor to river ecological restoration in the HRB. However, the South-to-North Water Diversion Project, the largest such project in the world, presents a good opportunity for ecological restoration of rivers in this basin. Water diverted from the Danjiangkou Reservoir will restore surface water resources in the HRB to levels of 30 years ago and will amount to more than 20 billion m(3). Our findings highlight the fact that water resources are crucial for river ecological restoration.

  12. Heavy metal accumulation by periphyton is related to eutrophication in the Hai River Basin, Northern China.

    Directory of Open Access Journals (Sweden)

    Wenzhong Tang

    Full Text Available The Hai River Basin (HRB is one of the most polluted river basins in China. The basin suffers from various types of pollutants including heavy metals and nutrients due to a high population density and rapid economic development in this area. We assessed the relationship between heavy metal accumulation by periphyton playing an important role in fluvial food webs and eutrophication in the HRB. The concentrations of the unicellular diatoms (type A, filamentous algae with diatoms (type B, and filamentous algae (type C varied along the river, with type A dominating upstream, and types B then C increasing in concentration further downstream, and this was consistent with changes in the trophic status of the river. The mean heavy metal concentrations in the type A, B and C organisms were Cr: 18, 18 and 24 mg/kg, respectively, Ni: 9.2, 10 and 12 mg/kg, respectively, Cu: 8.4, 19 and 29 mg/kg, respectively, and Pb: 11, 9.8 and 7.1 mg/kg respectively. The bioconcentration factors showed that the abilities of the organisms to accumulate Cr, Ni and Pb decreased in the order type A, type B, then type C, but their abilities to accumulate Cu increased in that order. The Ni concentration was a good predictor of Cr, Cu and Pb accumulation by all three periphyton types. Our study shows that heavy metal accumulation by periphyton is associated with eutrophication in the rivers in the HRB.

  13. Simulating Water Resource Disputes of Transboundary River: A Case Study of the Zhanghe River Basin, China

    Science.gov (United States)

    Yuan, Liang; He, Weijun; Liao, Zaiyi; Mulugeta Degefu, Dagmawi; An, Min; Zhang, Zhaofang

    2018-01-01

    Water resource disputes within transboundary river basin has been hindering the sustainable use of water resources and efficient management of environment. The problem is characterized by a complex information feedback loop that involves socio-economic and environmental systems. This paper presents a system dynamics based model that can simulate the dynamics of water demand, water supply, water adequacy and water allocation instability within a river basin. It was used for a case study in the Zhanghe River basin of China. The base scenario has been investigated for the time period between 2000 and 2050. The result shows that the Chinese national government should change the water allocation scheme of downstream Zhanghe River established in 1989, more water need to be allocated to the downstream cities and the actual allocation should be adjusted to reflect the need associated with the socio-economic and environmental changes within the region, and system dynamics improves the understanding of concepts and system interactions by offering a comprehensive and integrated view of the physical, social, economic, environmental, and political systems.

  14. Sunshine Duration Variability in Haihe River Basin, China, during 1966–2015

    Directory of Open Access Journals (Sweden)

    Jing Ren

    2017-10-01

    Full Text Available Sunshine can have a profound impact on the systematic change in climate elements, such as temperature and wind speed, and in turn affects many aspects of the human society. In recent years, there has been a substantial interest in the variation of sunshine duration due to the dramatic global climate change. Hence, there is a need to better understand the variation of sunshine duration in order to cope with climate change. This study aimed to analyze the variation of sunshine duration in Haihe River basin, China, and its relationship with temperature, wind speed and low-level cloudiness. The annual, seasonal and monthly changes of sunshine duration were analyzed based on the data collected from 33 meteorological stations over the Haihe River basin during 1966–2015. It is evident that the annual, seasonal and monthly sunshine duration shows a decreasing trend over time. In addition, the annual sunshine duration is lower with a higher climate tendency rate in the southern and eastern coastal regions than that in the northwestern regions. It is negatively correlated with temperature (r = −0.50 and low-level cloudiness (r = −0.29, but positively with wind speed (r = 0.61. Wind speed may be one of the important causes of the decrease of sunshine duration in the Haihe River basin during 1966–2015. These changes may have significant implications for the hydrological cycle in the area.

  15. Multiphase timing of hominin occupations and the paleoenvironment in Luonan Basin, Central China

    Science.gov (United States)

    Lu, Huayu; Zhang, Hongyan; Wang, Shejiang; Cosgrove, Richard; Sun, Xuefeng; Zhao, Jun; Sun, Donghuai; Zhao, Cunfa; Shen, Chen; Wei, Ming

    Thousands of Paleolithic artifacts have been recovered from Paleolithic sites in the Luonan Basin, in the upper South Luohe River of central China. Their discovery suggests that the basin was an important area for hominin settlement during the Pleistocene. However, the initial timing of this occupation and the environmental conditions for this period are still largely unknown. In addition, the sediments are not well dated and most of the artifacts lie on the surface. In an attempt to resolve these issues, a new systemic paleomagnetic analysis was carried out on the loess deposits that contain in situ stone tools. Our detailed loess-paleosol analyses of the stratigraphy of different sites in the basin and Chinese Loess Plateau shows the accumulation of the loess since at least 1.1 million years (Ma) ago. Moreover, recently discovered in situ cores, flakes and retouched stone tools in these deposits show that hominins used this region repeatedly from 0.8-0.7 Ma to 0.4-0.3 and 0.2-0.1 Ma. Pedostratigraphic analyses, magnetic susceptibility and carbon isotope analyses also indicate that these hominins lived in a subtropical to warm-temperate climate with broad-needle-leaf forest vegetation mixed with grasses.

  16. Analysis of Spatiotemporal Evolution of Isolated Rainstorm Events in Huai River Basin, China

    Directory of Open Access Journals (Sweden)

    Simin Liu

    2017-01-01

    Full Text Available Because of the impacts of extreme climate, the severity, areal extent, and frequency of rainstorm events are rapidly increasing, especially in the Huai River Basin of China. This article is based on hourly precipitation data of 229 meteorological stations from 1951 through 2012, combined with statistical and meteorological theory. We used the Mann-Kendall mutation test, moving t-test, and inverse distance weighting spatial interpolation to analyze the spatiotemporal evolution of precipitation, duration, intensity, and frequency of isolated rainstorm events under climate change. The main results are as follows: (1 isolated rainstorm events were obviously bimodal and their occurrence moved backward in time. Their average duration and time of maximum intensities changed dramatically, without a significant increasing trend. The period since the 2000s has seen an increase of rainstorms and their temporal regression across the entire basin. (2 The intensity of isolated rainstorm events in the study area decreased, but precipitation, its duration, areal extent, and frequency had increasing trends basin-wide. (3 Four rainstorm event indices were examined for the period of 1990–2000. Relative to the years before 2003, the average precipitation increased by 2.1%, the average total duration by 8.1%, and the average frequency of occurrence by 25.5%. All indices show smaller minimum and larger maximum values. Overall, the isolated rainstorm events tended to increase.

  17. Reservoir Space Evolution of Volcanic Rocks in Deep Songliao Basin, China

    Science.gov (United States)

    Zheng, M.; Wu, X.; Zheng, M.; HU, J.; Wang, S.

    2015-12-01

    Recent years, large amount of natural gas has been discovered in volcanic rock of Lower Crataceous of Songliao basin. Volcanic reservoirs have become one of the important target reservoir types of eastern basin of China. In order to study the volcanic reservoirs, we need to know the main factors controlling the reservoir space. By careful obsercation on volcanic drilling core, casting thin sections and statistical analysis of petrophysical properties of volcanic reservoir in Songliao basin, it can be suggested that the igneous rock reservoir in Yingcheng formation of Lower Crataceous is composed of different rock types, such ad rohylite, rohylitic crystal tuff, autoclastic brecciation lava and so on. There are different reservoirs storage space in in various lithological igneous rocks, but they are mainly composed of primary stoma, secondary solution pores and fractures.The evolution of storage space can be divided into 3 stage: the pramary reservoir space,exogenic leaching process and burial diagenesis.During the evolution process, the reservoir space is effected by secondary minerals, tectonic movement and volcanic hydrothermal solution. The pore of volcanic reservoirs can be partially filled by secondary minerals, but also may be dissoluted by other chemical volcanic hydrothermal solution. Therefore, the favorable places for better-quality volcanic reservoirs are the near-crater facies of vocanic apparatus and dissolution zones on the high position of paleo-structures.

  18. Assessment of gamma radiation levels and natural radioactivity in soils along a subtropical river basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Dekun; Yu, Tao [Third Institute of Oceanography, Xiamen (China). Lab. of Marine Isotopic Technology and Environmental Risk Assessment

    2017-07-01

    The activities of natural radionuclides in the environment can be used to assess radiological effects. Monitoring the radiation level in soils is important for public health. It also has important geochemical implications as most of the sediment eroded from river basins is from soil. Therefore, we carried out a soil sampling campaign along a subtropical river basin in southeastern China (Jiulong River). Surface and depth profile soils were collected, and the natural radionuclide activities were measured. The activities of the natural radionuclides {sup 238}U, {sup 232}Th, and {sup 40}K in the surface soils varied from 31.6 to 132.1 Bq kg-dry{sup -1}, 37.8 to 174.0 Bq kg-dry{sup -1}, and 52.3 to 596.2 Bq kg-dry{sup -1}, with average values of 56.7±30.3 Bq kg-dry{sup -1}, 86.7±41.3 Bq kg-dry{sup -1}, and 352.8±190.6 Bq kg-dry{sup -1}, respectively. The absorbed gamma dose in air and the annual effective dose equivalent (AEDE) in surface soils along the river basin were both higher than the world average. In the depth profiles, excess {sup 210}Pb ({sup 210}Pbex) decreased with depth and significant correlation between {sup 210}Pbex and TOC was observed, suggesting that they are affected by similar processes (leaching and sorption).

  19. Simulations of organic aerosol concentrations during springtime in the Guanzhong Basin, China

    Science.gov (United States)

    Feng, Tian; Li, Guohui; Cao, Junji; Bei, Naifang; Shen, Zhenxing; Zhou, Weijian; Liu, Suixin; Zhang, Ting; Wang, Yichen; Huang, Ru-jin; Tie, Xuexi; Molina, Luisa T.

    2016-08-01

    The organic aerosol (OA) concentration is simulated in the Guanzhong Basin, China from 23 to 25 April 2013 utilizing the WRF-CHEM model. Two approaches are used to predict OA concentrations: (1) a traditional secondary organic aerosol (SOA) module; (2) a non-traditional SOA module including the volatility basis-set modeling method in which primary organic aerosol (POA) is assumed to be semivolatile and photochemically reactive. Generally, the spatial patterns and temporal variations of the calculated hourly near-surface ozone and fine particle matters agree well with the observations in Xi'an and surrounding areas. The model also yields reasonable distributions of daily PM2.5 and elemental carbon (EC) compared to the filter measurements at 29 sites in the basin. Filter-measured organic carbon (OC) and EC are used to evaluate OA, POA, and SOA using the OC / EC ratio approach. Compared with the traditional SOA module, the non-traditional module significantly improves SOA simulations and explains about 88 % of the observed SOA concentration. Oxidation and partitioning of POA treated as semivolatile constitute the most important pathway for the SOA formation, contributing more than 75 % of the SOA concentrations in the basin. Residential emissions are the dominant anthropogenic OA source, constituting about 50 % of OA concentrations in urban and rural areas and 30 % in the background area. The OA contribution from transportation emissions decreases from 25 % in urban areas to 20 % in the background area, and the industry emission OA contribution is less than 6 %.

  20. Accumulation, transfer, and potential sources of mercury in the soil-wheat system under field conditions over the Loess Plateau, northwest China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shengli [Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Western China' s Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Nan, Zhongren, E-mail: nanzhongren@lzu.edu.cn [Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Western China' s Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Prete, Daniel [Department of Chemistry and Biology, Ryerson University, Toronto M5B 2K3 (Canada); Ma, Jianmin; Liao, Qin; Zhang, Qian [Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China)

    2016-10-15

    There is limited information on accumulation, transfer, and source of mercury in wheats under field conditions over the Loess Plateau, northwest China. The present study collected 26 pairs of topsoil and whole wheat samples (roots, stems, leaves, shells, and grains) from Dongdagou stream watershed and upper Xidagou stream watershed, Baiyin City, northwest China. Hg concentrations from these samples were used to identify their relationships with soil properties, interactions with other metals, localization of Hg in the different wheat tissues, bio-concentration and transfer of Hg, and major sources of Hg in wheat. Results show that Hg levels in 11 out of 26 sampled soils (42.3% of soil samples) exceeded Hg limit of grade II soil environmental quality standards in China (1.0 mg·kg{sup −} {sup 1}). Likewise, it was also found that Hg in over 50% of wheat grain samples reached or exceeded the maximum permissible food safety levels (0.02 mg·kg{sup −} {sup 1}) according to the General Standard of Contaminants in Food in China (GB 2762-2012). The spatial distribution pattern of Hg in wheats grains was different from that in the sampled soils. Hg concentrations in different wheat tissues were highest in roots, followed by leaves, stalks, shells, and grains, respectively. Bio-concentration factors (BCF) of Hg in almost all grains samples were one or two orders of magnitude lower than that in roots, except for two wheat samples. The translocation factors (TF) of Hg in wheat tissues on average were leaves > stems > shells > grains. The spatial distribution of Hg and its correlation with other heavy metal detected simultaneously in the soil samples suggested that the Hg soil contamination was probably caused by past sewage irrigation practices and atmospheric deposition. Correlation analysis revealed that the principle source of Hg in wheat roots was very likely from Hg contaminated soils. - Highlights: • Hg concentrations in wheats and corresponding soils from loess

  1. Groundwater Depth Affects Phosphorus But Not Carbon and Nitrogen Concentrations of a Desert Phreatophyte in Northwest China.

    Science.gov (United States)

    Zhang, Bo; Gao, Xiaopeng; Li, Lei; Lu, Yan; Shareef, Muhammad; Huang, Caibian; Liu, Guojun; Gui, Dongwei; Zeng, Fanjiang

    2018-01-01

    Ecological stoichiometry is an important aspect in the analysis of the changes in ecological system composition, structure, and function and understanding of plant adaptation in habitats. Leaf carbon (C), nitrogen (N), and phosphorus (P) concentrations in desert phreatophytes can be affected by different depths of groundwater through its effect on the adsorption and utilization of nutrient and plant biomass. We examined the biomass, soil organic C, available (mineral) N, and available P, and leaf C, N, and P concentrations of Alhagi sparsifolia grown at varying groundwater depths of 2.5, 4.5, and 11.0 m in 2015 and 2016 growing seasons in a desert-oasis ecotone in northwest China. The biomass of A. sparsifolia and the C, N, and P concentrations in soil and A. sparsifolia showed different responses to various groundwater depths. The leaf P concentration of A. sparsifolia was lower at 4.5 m than at 2.5 and 11.0 m likely because of a biomass dilution effect. By contrast, leaf C and N concentrations were generally unaffected by groundwater depth, thereby confirming that C and N accumulations in A. sparsifolia were predominantly determined by C fixation through the photosynthesis and biological fixation of atmospheric N 2 , respectively. Soil C, N, and P concentrations at 4.5 m were significantly lower than those at 11.0 m. Leaf P concentration was significantly and positively correlated with soil N concentration at all of the groundwater depths. The C:N and C:P mass ratios of A. sparsifolia at 4.5 m were higher than those at the other groundwater depths, suggesting a defensive life history strategy. Conversely, A. sparsifolia likely adopted a competitive strategy at 2.5 and 11.0 m as indicated by the low C:N and C:P mass ratios. To our knowledge, this study is the first to elucidate the variation in the C, N, and P stoichiometry of a desert phreatophyte at different groundwater depths in an arid ecosystem.

  2. Changes in Socioeconomic Inequality of Low Birth Weight and Macrosomia in Shaanxi Province of Northwest China, 2010–2013

    Science.gov (United States)

    Pei, Leilei; Kang, Yijun; Zhao, Yaling; Cheng, Yue; Yan, Hong

    2016-01-01

    Abstract Socioeconomic disparities in birth weights (BWs) are associated with lifelong differences in health and productivity. Understanding socioeconomic disparities in BW is presently of concern to develop public health interventions that promote a good start in life in Northwest China. In the study, our objective is to investigate the socioeconomic disparities in low and high BW from 2010 to 2013 in this region. Those single live births were recruited using a stratified multistage sampling method in Shaanxi province from August to December 2013. Data were collected with a structured questionnaire and a review of birth certificates. Socioeconomic status (SES) was stratified based on the calculated household wealth index. Prevalence differences (PDs) and concentration indices (CIs) were used to depict the SES inequality of low BW (LBW) and macrosomia. Information for 28722 single live births born were obtained in Shaanxi province. From 2010 to 2013, the overall rates of LBW decreased, and the difference in LBW across differing SES groups decreased by 0.7% (boys, 0.4%; girls, 0.8%). From 2010 to 2013, the overall rates of macrosomia increased by 14.3% (boys, 17.5%; girls, 7.8%), whereas the PDs in macrosomia across various SES groups remained unchanged. From 2010 to 2013, concentration indices for SES inequalities in LBW and macrosomia confirmed the results shown by differences in prevalence. Compared with mothers of high SES, those in low SES group were significantly older, less educated, engaged in farming with less availabile healthcare, and engaged in unhealthy lifestyles (eg, exposure to secondhand smoke) during pregnancy, regardless of the baby's sex. From 2010 to 2013, in Shaanxi province, the negative association between socioeconomic status and LBW weakened. Rates of macrosomia were higher in those of high SES, but the SES disparities varied insignificantly over the same time. Our findings may provide valuable insights to direct healthcare policies for

  3. Chemical composition, sources, and processes of urban aerosols during summertime in Northwest China: insights from High Resolution Aerosol Mass Spectrometry

    Science.gov (United States)

    Xu, J.; Zhang, Q.; Chen, M.; Ge, X.; Ren, J.; Qin, D.

    2014-06-01

    An aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed along with a Scanning Mobility Particle Sizer (SMPS) and a Multi Angle Absorption Photometers (MAAP) to measure the temporal variations of the mass loading, chemical composition, and size distribution of sub-micrometer particulate matter (PM1) in Lanzhou, northwest China, during 12 July-7 August 2012. The average PM1 mass concentration including non-refractory PM1 (NR-PM1) measured by HR-ToF-AMS and black carbon (BC) measured by MAAP during this study was 24.5 μg m-3 (ranging from 0.86 to 105μg m-3), with a mean composition consisting of 47% organics, 16% sulfate, 12% BC, 11% ammonium, 10% nitrate, and 4% chloride. The organics was consisted of 70% carbon, 21% oxygen, 8% hydrogen, and 1% nitrogen, with the average oxygen-to-carbon ratio (O / C) of 0.33 and organic mass-to-carbon ratio (OM / OC) of 1.58. Positive matrix factorization (PMF) of the high-resolution mass spectra of organic aerosols (OA) identified four distinct factors which represent, respectively, two primary OA (POA) emission sources (traffic and food cooking) and two secondary OA (SOA) types - a fresher, semi-volatile oxygenated OA (SV-OOA) and a more aged, low-volatility oxygenated OA (LV-OOA). Traffic-related hydrocarbon-like OA (HOA) and BC displayed distinct diurnal patterns both with peak at ~07:00-11:00 (BJT: UTC +8) corresponding to the morning rush hours, while cooking OA (COA) peaked during three meal periods. The diurnal profiles of sulfate and LV-OOA displayed a broad peak between ∼07:00-15:00, while those of nitrate, ammonium, and SV-OOA showed a narrower peak at ~08:00-13:00. The later morning and early afternoon peak in the diurnal profiles of secondary aerosol species was likely caused by mixing down of pollutants aloft, which were likely produced in the residual layer decoupled from the boundary layer during night time. The mass spectrum of SV-OOA also showed similarity with that of

  4. Diurnal and seasonal variations in carbon dioxide exchange in ecosystems in the Zhangye oasis area, Northwest China.

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    Full Text Available Quantifying carbon dioxide exchange and understanding the response of key environmental factors in various ecosystems are critical to understanding regional carbon budgets and ecosystem behaviors. For this study, CO2 fluxes were measured in a variety of ecosystems with an eddy covariance observation matrix between June 2012 and September 2012 in the Zhangye oasis area of Northwest China. The results show distinct diurnal variations in the CO2 fluxes in vegetable field, orchard, wetland, and maize cropland. Diurnal variations of CO2 fluxes were not obvious, and their values approached zero in the sandy desert, desert steppe, and Gobi ecosystems. Additionally, daily variations in the Gross Primary Production (GPP, Ecosystem Respiration (Reco and Net Ecosystem Exchange (NEE were not obvious in the sandy desert, desert steppe, and Gobi ecosystems. In contrast, the distributions of the GPP, Reco, and NEE show significant daily variations, that are closely related to the development of vegetation in the maize, wetland, orchard, and vegetable field ecosystems. All of the ecosystems are characterized by their carbon absorption during the observation period. The ability to absorb CO2 differed significantly among the tested ecosystems. We also used the Michaelis-Menten equation and exponential curve fitting methods to analyze the impact of Photosynthetically Active Radiation (PAR on the daytime CO2 flux and impact of air temperature on Reco at night. The results show that PAR is the dominant factor in controlling photosynthesis with limited solar radiation, and daytime CO2 assimilation increases rapidly with PAR. Additionally, the carbon assimilation rate was found to increase slowly with high solar radiation. The light response parameters changed with each growth stage for all of the vegetation types, and higher light response values were observed during months or stages when the plants grew quickly. Light saturation points are different for different

  5. [Moisture and nutrient characteristics of deep layer soil in apple orchards on the Luochuan highland of Shaanxi, Northwest China].

    Science.gov (United States)

    Cao, Yu; Jumahan, Kasimu; Fan, Peng; Zhang, Li-Na; Li, Jun

    2013-02-01

    Taking the 11-, 15-, 20-, and 43 years old apple orchards on the Luochuan highland of Shaanxi, Northwest China as test objects, this paper measured the moisture content in 0-1500 cm soil layer and the organic matter and total and available nitrogen, phosphorous, and potassium contents in 0-300 cm soil layer, with the soil moisture and nutrient regimes as well as their variation characteristics with apple tree age and soil depth analyzed. The moisture content in 0-1500 cm soil layer in 11-, 15-, 20-, and 43 years old apple orchards was averagely 18.6%, 13.7%, 17.0%, 11.5%, and 13.1%, respectively, and decreased with apple tree age. Soil desiccation did not occurr in the orchards with supplementary irrigation, but a slight or medium soil desiccation occurred in the rainfed orchards. Nevertheless, the moisture content in 0-300 cm soil layer in the rainfed orchards was still higher than that in wheat field. The contents of organic matter and total and available nitrogen in 0-300 cm soil layer in the five apple orchards were less than 10 g.kg-1, 0.75 g. kg-1, and 50 mg.kg-1, respectively, all at shortage level, whilst the content of available phosphorous in 0-300 cm soil layer was 3.30-6.42 mg.kg-1, being moderate in upper soil layer and scarce in deep soil layer. The content of available potassium in 0-300 cm soil layer was 78.09-98.31 mg.kg-1, presenting abundant. The contents of nutrients were all higher in 0-100 cm soil layer than in 100-300 cm soil layer. The soil organic matter and total and available nitrogen contents and the soil nutrient index (SNI) all presented a trend of decrease after an initial increase with the increasing apple tree age. The contents of the test nutrients except total potassium in 0-100 cm soil layer all decreased rapidly with soil depth, while those in deeper soil layers kept relatively stable. There existed significant correlations between the contents of soil organic matter, total nitrogen, available nitrogen, total phosphorous

  6. Slope-apron deposition in an ordovician arc-related setting: The Vuelta de Las Tolas Member (Suri Formation), Famatina Basin, northwest Argentina

    Science.gov (United States)

    Mangano, M.G.; Buatois, L.A.

    1997-01-01

    The Ordovician Suri Formation is part of the infill of the Famatina Basin of northwest Argentina, which formed in an active setting along the western margin of early Paleozoic Gondwana. The lower part of this formation, the Vuelta de Las Tolas Member, records sedimentation on a slope apron formed in an intra-arc basin situated on a flooded continental arc platform. The coincidence of a thick Arenig-Llanvirn sedimentary succession and volcanic-plutonic arc rocks suggests an extensional or transtensional arc setting, and is consistent with evidence of an extensional regime within the volcanic arc in the northern Puna region. The studied stratigraphic sections consist of volcanic rocks and six sedimentary facies. The facies can be clustered into four facies associations. Association 1, composed of facies A (laminated siltstones and mudstones) and B (massive mudstones and siltstones), is interpreted to have accumulated from silty-muddy high-and low-density turbidity currents and highly fluid, silty debris flows, with subsequent reworking by bottom currents, and to a lesser extent, hemipelagic suspension in an open-slope setting. Facies association 2 is dominated by facies C (current-rippled siltstones) strata. These deposits are interpreted to record overbank sedimentation from fine-grained turbidity currents. Facies E (matrix-supported volcanic breccias) interbedded with andesitic lava units comprises facies association 3. Deposition was contemporaneous with subaqueous volcanic activity, and accumulated from cohesive debris flows in a coarse-grained wedge at the base of slope. Facies association 4 is typified by facies D (vitric fine-grained sandstones and siltstones) and F (channelized and graded volcanic conglomerates and breccias) deposits. These strata commonly display thinning-and fining-upward trends, indicating sedimentation from highly-concentrated volcaniclastic turbidity currents in a channelized system. The general characteristics of these deposits of fresh

  7. Hydrological effects of cropland and climatic changes in arid and semi-arid river basins: A case study from the Yellow River basin, China

    Science.gov (United States)

    Li, Huazhen; Zhang, Qiang; Singh, Vijay P.; Shi, Peijun; Sun, Peng

    2017-06-01

    The Yellow River basin is a typical semi-arid river basin in northern China. Serious water shortages have negative impacts on regional socioeconomic development. Recent years have witnessed changes in streamflow processes due to increasing human activities, such as agricultural activities and construction of dams and water reservoirs, and climatic changes, e.g. precipitation and temperature. This study attempts to investigate factors potentially driving changes in different streamflow components defined by different quantiles. The data used were daily streamflow data for the 1959-2005 period from 5 hydrological stations, daily precipitation and temperature data from 77 meteorological stations and data pertaining to cropland and large reservoirs. Results indicate a general decrease in streamflow across the Yellow River basin. Moreover significant decreasing streamflow has been observed in the middle and lower Yellow River basin with change points during the mid-1980s till the mid-1990s. The changes of cropland affect the streamflow components and also the cumulative effects on streamflow variations. Recent years have witnessed moderate cropland variations which result in moderate streamflow changes. Further, precipitation also plays a critical role in changes of streamflow components and human activities, i.e. cropland changes, temperature changes and building of water reservoirs, tend to have increasing impacts on hydrological processes across the Yellow River basin. This study provides a theoretical framework for the study of the hydrological effects of human activities and climatic changes on basins over the globe.

  8. Organic walled dinoflagellate cysts from the Tarim Basin, western China: Implications for the retreat of the Paratethys Sea

    NARCIS (Netherlands)

    Grothe, A.; Houben, A.J.P.; Bosboom, R.E.; Dupont-Nivet, G.; Brinkhuis, H.

    2011-01-01

    Paleogene sediments of the Tarim basin in western China hold the easternmost extent of the Paratethys Sea, an epicontinental sea that covered a large part of Eurasia and probably extended to the Mediterranean Tethys in the west. The late Cretaceous and Paleogene sedimentary record of the

  9. Integrated assessment of agricultural land use policies on nutrient pollution and sustainable development in Taihu Basin, China

    NARCIS (Netherlands)

    Reidsma, P.; Feng, S.; Loon, van M.; Luo, X.; Kang, C.; Lubbers, M.T.M.H.; Kanellopoulos, A.; Wolf, J.; Ittersum, van M.K.; Qu, F.

    2012-01-01

    Water pollution in Chinese lakes is a major problem. To reduce nutrient pollution and enhance sustainable development in Taihu Basin, China, an integrated assessment of the impacts of agricultural land use policies has been performed, using the technical coefficient generator TechnoGIN and the

  10. Annual runoff and evapotranspiration of forestlands and non-forestlands in selected basins of the Loess Plateau of China.

    Science.gov (United States)

    Yanhui Wang; Pengtao Yu; Karl-Heinz Feger; Xiaohua Wei; Ge Sun; et al

    2011-01-01

    Large-scale forestation has been undertaken over decades principally to control the serious soil erosion in the Loess Plateau of China. A quantitative assessment of the hydrological effects of forestation, especially on basin water yield, is critical for the sustainable forestry development within this dry region. In this study, we constructed the multi-annual water...

  11. Molecular isotopic characterisation of hydrocarbon biomarkers in Palaeocene-Eocene evaporitic, lacustrine source rocks from the Jianghan Basin, China

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Grice, Kliti; Schouten, S.; Peters, Kenneth E.

    1998-01-01

    Immature organic matter in lacustrine source rocks from the Jianghan Basin, eastern China, was studied for distributions and stable carbon isotopic compositions (13C) of hydrocarbon biomarkers. All of the bitumens contain isorenieratane (13C ca. −17 ) indicating the presence of Chlorobiaceae, and

  12. Ichnological constraints on the depositional environment of the Sawahlunto Formation, Kandi, northwest Ombilin Basin, west Sumatra, Indonesia

    Science.gov (United States)

    Zonneveld, J.-P.; Zaim, Y.; Rizal, Y.; Ciochon, R. L.; Bettis, E. A.; Aswan; Gunnell, G. F.

    2012-02-01

    A low diversity trace fossil assemblage is described from the Oligocene Sawahlunto Formation near Kandi, in the northwestern part of the Ombilin Basin in western Sumatra, Indonesia. This trace fossil assemblage includes six ichnogenera attributed to invertebrate infaunal and epifaunal activities ( Arenicolites, Diplocraterion, Planolites, Monocraterion/ Skolithos and Coenobichnus) and two ichnotaxa attributed to vertebrate activity (avian footprints: two species of Aquatilavipes). Arenicolites, Diplocraterion and Monocraterion/ Skolithos record the suspension feeding activities of either arthropods (most likely amphipods) or vermiform organisms. Planolites reflects the presence of an infaunal deposit feeder. Coenobichnus records the walking activities of hermit crabs. Both the Coenobichnus and the avian footprints record the surficial detritus scavenging of epifaunal organisms within a subaerial setting. These traces occur within a fine-grained sandstone succession characterized by planar laminae and low-relief, asymmetrical, commonly mud-draped (locally bidirectional) ripples. The presence of traces attributable to suspension feeders implies deposition in a subaqueous setting. Their occurrence (particularly the presence of Arenicolites and Diplocraterion) in a sandstone bed characterized by mud-draped and bidirectional ripples implies emplacement in a tidally-influenced marine to marginal marine setting. Co-occurrence of these traces with well-preserved avian footprints ( Aquatilavipes) further implies periodic subaerial exposure. Thus, it is most likely that the Sawahlunto Formation near Kandi records deposition within an intertidal flat setting. Definitive evidence of marine influences in the Oligocene interval of the Ombilin Basin implies a more complex tectono-stratigraphic history than has previously been implied.

  13. Uplifting of the Jiamusi Block in the eastern Central Asian Orogenic Belt, NE China: evidence from basin provenance and geochronology

    Science.gov (United States)

    Liu, Yongjiang; Wen, Quanbo; Han, Guoqing; Li, Wei

    2010-05-01

    The main part of Jiamusi Block, named as Huanan-Uplift, is located in the northeastern Heilongjiang, China. The Huanan-Uplift is surrounded by many relatively small Mesozoic-Cenozoic basins, e.g. Sanjiang Basin, Hulin Basin, Boli Basin, Jixi Basin, Shuangyashan Basin and Shuanghua Basin. However previous research works were mainly focused on stratigraphy and palaeontology of the basins, therefore, the coupling relation between the uplift and the surrounding basins have not been clear. Based on the field investigations, conglomerate provenance studies of the Houshigou Formation in Boli Basin, geochronology of the Huanan-Uplift basement, we have been studied the relationships between Huanan-Uplift and the surrounding basins. The regional stratigraphic correlations indicates that the isolated basins in the area experienced the same evolution during the period of the Chengzihe and the Muling Formations (the Early Cretaceous). The paleogeography reconstructions suggest that the area had been a large-scale basin as a whole during the Early Cretaceous. The Huanan-Uplift did not exist. The paleocurrent directions, sandstone and conglomerate provenance analyses show that the Huanan-Uplift started to be the source area of the surrounding basins during the period of Houshigou Formation (early Late Cretaceous), therefore, it suggests that the Jiamusi Block commenced uplift in the early Late Cretaceous. The granitic gneisses in Huanan-Uplift give 494-415 Ma monazite U-Th-total Pb ages, 262-259 Ma biotite and 246-241 Ma K-feldspar 40Ar/39Ar ages. The cooling rates of 1-2 ℃/Ma from 500-260 Ma and 10-11 ℃/Ma from 260-240 Ma have been calculated based on the ages. This suggests that the Jiamusi Block had a rapid exhumation during late Permian, which should be related to the closure of the Paleo-Asian Ocean between the Siberian and North China continents. It is concluded that during the late Paleozoic the Jiamusi Block was stable with a very slow uplifting. With the closure of

  14. The depositional setting of the Late Quaternary sedimentary fill in southern Bannu basin, Northwest Himalayan fold and thrust belt, Pakistan

    KAUST Repository

    Farid, Asam M.

    2014-07-10

    Geostatistical variogram and inversion techniques combined with modern visualization tools have made it possible to re-model one-dimensional electrical resistivity data into two-dimensional (2D) models of the near subsurface. The resultant models are capable of extending the original interpretation of the data to depict alluvium layers as individual lithological units within the 2D space. By tuning the variogram parameters used in this approach, it is then possible to visualize individual lithofacies and geomorphological features for these lithologic units. The study re-examines an electrical resistivity dataset collected as part of a groundwater study in an area of the Bannu basin in Pakistan. Additional lithological logs from boreholes throughout the area have been combined with the existing resistivity data for calibration. Tectonic activity during the Himalayan orogeny uplifted and generated significant faulting in the rocks resulting in the formation of a depression which subsequently has been filled with clay-silt and dirty sand facies typical of lacustrine and flood plain environments. Streams arising from adjacent mountains have reworked these facies which have been eroded and replaced by gravel-sand facies along channels. It is concluded that the sediments have been deposited as prograding fan shaped bodies, flood plain, and lacustrine deposits. Clay-silt facies mark the locations of paleo depressions or lake environments, which have changed position over time due to local tectonic activity and sedimentation. The Lakki plain alluvial system has thus formed as a result of local tectonic activity with fluvial erosion and deposition characterized by coarse sediments with high electrical resistivities near the mountain ranges and fine sediments with medium to low electrical resistivities towards the basin center. © 2014 Springer International Publishing Switzerland.

  15. Physical properties, vitrinite reflectance, and microstructure of coal, Taiyuan Formation, Qinshui Basin, China

    Science.gov (United States)

    Li, Qiong; Chen, Jie; He, Jian-Jun

    2017-12-01

    In this study, we experimentally established the relationship between physical properties, vitrinite reflectance, and microstructure of coal, Taiyuan Formation, Qinshui Basin, China using representative coal samples collected from three different mines via the rock mechanics testing system (MTS). We analyzed the organic macerals, vitrinite reflectance, and microstructure of 11 coal samples using petrography and scanning electron microscopy (SEM). The experimental results suggest that (1) the elastic parameters can be described by linear equations, (2) both P-and S-wave velocities display anisotropy, (3) the anisotropy negatively correlates with vitrinite reflectance, and (4) the acoustic velocities and Young's modulus are negatively correlated with the volume of micropores. The derived empirical equations can be used in the forward modeling and seismic inversion of physical properties of coal for improving the coal-bed methane (CBM) reservoir characterization.

  16. Feasibility of CO{sub 2} geological storage in the Xingou oil field, Jianghan Basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Sanxi [School of Environmental Studies, China University of Geosciences, Wuhan, 430074 (China); Changsha Engineering and Research Institute Ltd. of Nonferrous Metallurgy, Changsha, 410001 (China); Shana, Huimei; Li, Yilian [School of Environmental Studies, China University of Geosciences, Wuhan, 430074 (China); Yang, Zhen; Zhong, Zhaohong [Changsha Engineering and Research Institute Ltd. of Nonferrous Metallurgy, Changsha, 410001 (China)

    2013-07-01

    Geological storage of CO{sub 2} as an effective way of reducing CO{sub 2} output to the atmosphere receives growing attention worldwide. To evaluate the feasibility of this technique in the Xingou oil field of Jianghan Basin in China, 2D and 3D models of CO{sub 2} geological storage were established using TOUGH2 software. Results showed that CO{sub 2} gas can be stored in the deepest reservoir through continuous injection over 50 years, and will remain effectively confined within the space under the second cap-rock during its diffusion over 500 years. Compared with 2D models, 3D models showed that the diffusion process of CO{sub 2} gas in the reservoir will create a mushroom-shaped zone of influence. (authors)

  17. The collision of South China with NW India to join Gondwanaland in the Cambrian: Provenance constraints from foreland basins

    Science.gov (United States)

    Yao, W.; Li, Z.; Li, W.; Li, X.; Yang, J.

    2013-12-01

    The paleogeographic position of the South China Block (SCB) during the early Paleozoic is important for understanding its affinity with Gondwanaland and addressing potential tectonic trigger for both the early Paleozoic Wuyi-Yunkai orogeny in South China and similar-aged orogenic events along Gondwanan margins. Detrital zircon U-Pb ages of Cambrian sandstones/metasandstones from the southwestern SCB reveal a predominant population at 1100¬-950 Ma, and zircon Hf-O isotopic results suggest three Precambrian episodes of juvenile crustal growth for the source provenance (ca. 3.0 Ga, ca. 2.5 Ga and ca. 1.0 Ga), with major crustal reworking at 0.58-0.50 Ga. This provenance record is distinctly different from the known tectonomagmatic record of the SCB, but matches well with the provenance record of Cambrian sandstones and Cambro-Ordovician tectonomagmatic events in the NW Indian Himalaya. Such a provenance linkage between the two continents appears to have started from the Ediacaran. We thus propose that the SCB likely collided with NW India during the assembling of Gondwanaland between the Ediacaran and the Cambrian. The collisional event propagated to eastern Himalaya during Cambro-Ordovician time as South China rotated relative to India to close the remnant ocean, causing the Cambro-Ordovician North India orogeny (also known as the Kurgiakh orogeny) along the Himalaya, as well as the intraplate Wuyi-Yunkai orogeny (>460-415 Ma) in South China. This collisional event also generated two peripheral foreland basins on both the Indian Gondwanaland and the South China sides. The foreland basin on the South China side (the Nanhua foreland basin), started as a failed Neoproterozoic continental rift, and appears to have experienced two stage of development. During the first stage between the Ediacaran and the Cambrian, the basin likely shared the same detrital sources as the foreland basin in NW India, with sediments predominantly derived from the East Africa orogen and the

  18. Sedimentary and Paleoceanographic Responses to the South China Sea Basin Evolution

    Science.gov (United States)

    Jian, Z.; Liu, Z.; Jin, H.; Larsen, H. C.; Alvarez Zarikian, C. A.; Stock, J. M.; Sun, Z.; Klaus, A.

    2017-12-01

    As the largest marginal sea of the western Pacific, the South China Sea (SCS) has experienced a complete Wilson cycle, which had inevitably exerted a profound impact on the sedimentary environment and ocean circulation. Based on the results of four ODP/IODP expeditions to the SCS since 1999, together with other research data in this region, this study aims to explore the sedimentary and paleoceanographic responses to the tectonic events and basin evolution in the SCS. The early history of the SCS from land to deep sea was revealed by foraminiferal fauna: (1) The SCS evolved from continental shelf to an upper bathyal environment around the Oligocene/Eocene boundary, and significantly deepened at the turn of Oligocene/Miocene; (2) The early Oligocene SCS was deep but its shelf was narrow, evidenced by the Para-Tethys type deep-sea agglutinated benthic foraminifers and abundant transported shallow-water species at ODP Site 1148. Along with the SCS basin formation and the development of this semi-closed basin, the deep-sea benthic foraminiferal δ13C decreased when the Antarctic ice sheet began to reestablish at 14 Ma, the Indonesian Seaway and the southern SCS deep-water channel were closed at 10 Ma, the Luzon arc collided with Taiwan at 6.5 Ma, and the Bashi Strait was restricted at 1.2 Ma. Nd isotopes of shark teeth at ODP Site 1148 also support these inferences. An early to middle Miocene succession of red clay was found at all sites deeper than 3500 m water depth, which may be correlated to a basin-wide event related to deep circulation of oxygenated water from the western Pacific. After the earliest late Miocene carbonate crash, the red clay disappeared while the large carbonate platforms were drowned and remarkably shrank in the SCS. Late Miocene sediments display a succession of hemi-pelagic and turbidite deposits, indicating that the deep basin entered its modern state below the CCD. Frequent turbidites ended when Pliocene growth of deep-sea manganese

  19. Oxygenation of a Cryogenian ocean (Nanhua Basin, South China) revealed by pyrite Fe isotope compositions

    Science.gov (United States)

    Zhang, Feifei; Zhu, Xiangkun; Yan, Bin; Kendall, Brian; Peng, Xi; Li, Jin; Algeo, Thomas J.; Romaniello, Stephen

    2015-11-01

    The nature of ocean redox chemistry between the Cryogenian Sturtian and Marinoan glaciations (ca. 663-654 Ma) is important for understanding the relationship between environmental conditions and the subsequent emergence and expansion of early animals. The Cryogenian-to-Ediacaran stratigraphic succession of the Nanhua Basin in South China provides a nearly complete sedimentary record of the Cryogenian, including a continuous record of interglacial sedimentation. Here, we present a high-resolution pyrite Fe isotope record for a ∼120-m-long drill-core (ZK105) through Sturtian glacial diamictites and the overlying interglacial sediments in the Nanhua Basin to explore changes in marine chemistry during the late Cryogenian. Our pyrite Fe isotope profile exhibits significant stratigraphic variation: Interval I, comprising middle to upper Tiesi'ao diamictites (correlative with the Sturtian glaciation), is characterized by light, modern seawater-like Fe isotope compositions; Interval II, comprising uppermost Tiesi'ao diamictites and the basal organic-rich Datangpo Formation, is characterized by an abrupt shift to heavier Fe isotope compositions; and Interval III, comprising organic-poor grey shales in the middle Datangpo Formation, is characterized by the return of lighter, seawater-like Fe isotope compositions. We infer that Interval I pyrite was deposited in a predominantly anoxic glacial Nanhua Basin through reaction of dissolved Fe2+ and H2S mediated by microbial sulfate reduction (MSR). The shift to heavier pyrite Fe isotope values in Interval II is interpreted as partial oxidation of ferrous iron to ferric iron and subsequent near-quantitative reduction and transformation of Fe-oxyhydroxides to pyrite through coupling with oxidation of organic matter in the local diagenetic environment. In Interval III, near-quantitative oxidation of ferrous iron to Fe-oxyhydroxides followed by near-quantitative reduction and conversion to pyrite in the local diagenetic environment

  20. Groundwater recharge history and hydrogeochemical evolution in the Minqin Basin, North West China

    Energy Technology Data Exchange (ETDEWEB)

    Edmunds, W.M. [Oxford Centre for Water Research, Oxford University Centre for the Environment, Oxford University, Oxford OX1 3QY (United Kingdom)]. E-mail: wme@btopenworld.com; Ma, Jinzhu [CAEP, Key Laboratory of West China' s Environmental System (Ministry of Education), Lanzhou University, Lanzhou 730000 (China); Aeschbach-Hertig, W. [Institut fuer Umweltphysik, Universitaet Heidelberg, D-69120 Heidelberg (Germany); Kipfer, R. [Isotope Geology, ETH, CH-8092, Zurich (Switzerland); Darbyshire, D.P.F. [NERC Isotope Geoscience Laboratory, Keyworth, Nottingham, NG12 5GG (United Kingdom)

    2006-12-15

    concentrations of around 2 mg L{sup -1} but there is little evidence of impact of high NO{sub 3} from irrigation returns. Strontium isotope and major ion ratios suggest that silicate reactions predominate in the aquifer. The results have important implications for groundwater management in the Minqin and other water-stressed basins in NW China - a region so far destined for rapid development. The large proportion of the water being used at present is in effect being mined and significant changes are urgently needed in water use strategy.

  1. Occurrence, distribution and bioaccumulation of antibiotics in the Liao River Basin in China.

    Science.gov (United States)

    Bai, Yangwei; Meng, Wei; Xu, Jian; Zhang, Yuan; Guo, Changsheng

    2014-03-01

    The occurrence and distribution of 19 antibiotics including ten sulfonamides, four quinolones, three tetracyclines and two macrolides in water, sediment, and biota samples from the Liao River Basin, China were investigated in the present study. The samples were collected in May 2012, and laboratory analyses revealed that antibiotics were widely distributed in the Liao River Basin. Macrolides made up the majority of antibiotics in the water ranging from not detected (ND) to 3162.22 ng L(-1), while tetracyclines and macrolides were the predominant antibiotics in the sediments, ranging from ND to 404.82 μg kg(-1) (mean 32.11 μg kg(-1) dw) and ND to 375.13 (mean 32.77 μg kg(-1) dw), with detection frequencies of 37.3% and 38.1%, respectively. In biological samples, quinolones were the most frequently detected antibiotics (57.1-100%), with concentrations ranging from 286.6-1655.3 μg kg(-1). The highest bioaccumulation factor (BAF) of 45407 L kg(-1) was found for enrofloxacin. The phase distribution calculation showed that tetracyclines were the most strongly adsorbed antibiotics in the sediment, with the highest pseudo-partitioning coefficient values, ranging from 1299 to 1499 L kg(-1). The geographical differences of antibiotic concentrations were largely due to anthropogenic activities and the sewage discharges from the local cities along the rivers.

  2. Low Flow Regimes of the Tarim River Basin, China: Probabilistic Behavior, Causes and Implications

    Directory of Open Access Journals (Sweden)

    Peng Sun

    2018-04-01

    Full Text Available Droughts are a frequent occurrence in Xinjiang, China, and therefore fundamental to determining their hydrologic characteristics is low flow analysis. To that end, 11 probability distribution functions and 26 copulas functions were employed to analyze the changing characteristics of low flow regime (defined as seven-day low flow of the Tarim River Basin. Results indicated that: (1 The Wakeby distribution satisfactorily described the probabilistic behavior of the low flow regime. According to Akaike Information Criterion (AIC, Bayesian Information Criterions (BIC, maximum likelihood, and other residual-based metrics, Tawn copula, Farlie–Gumbel–Morgenstern copula and Frank copula were the best choice and used in this current study. (2 After 1987, hydrological droughts of longer return periods were prone to higher occurrence frequency. (3 The low flow volume has been increasing in recent years due to the temperature-induced increase of snowmelt and increasing precipitation. However, hydrological droughts can be expected to occur due to the massive increase in water demand from the development of irrigated agriculture, increasing arable land and livestock farming. As a result, the water shortage in the lower Tarim River Basin will be increasingly severe under the influence of climate change and human activities. To alleviate the shortage would call for the development of water-saving agricultural irrigation, water-saving technology, conservation of eco-environment and sustainable development of local socio-economy.

  3. Seismic shaking in the North China Basin expected from ruptures of a possible seismic gap

    Science.gov (United States)

    Duan, Benchun; Liu, Dunyu; Yin, An

    2017-05-01

    A 160 km long seismic gap, which has not been ruptured over 8000 years, was identified recently in North China. In this study, we use a dynamic source model and a newly available high-resolution 3-D velocity structure to simulate long-period ground motion (up to 0.5 Hz) from possibly worst case rupture scenarios of the seismic gap. We find that the characteristics of the earthquake source and the local geologic structure play a critical role in controlling the amplitude and distribution of the simulated strong ground shaking. Rupture directivity and slip asperities can result in large-amplitude (i.e., >1 m/s) ground shaking near the fault, whereas long-duration shaking may occur within sedimentary basins. In particular, a deep and closed Quaternary basin between Beijing and Tianjin can lead to ground shaking of several tens of cm/s for more than 1 min. These results may provide a sound basis for seismic mitigation in one of the most populated regions in the world.

  4. Microseepage of methane to the atmosphere from the Dawanqi oil-gas field, Tarim Basin, China

    Science.gov (United States)

    Tang, Junhong; Xu, Yue; Wang, Guojian; Etiope, Giuseppe; Han, Wei; Yao, Zhitong; Huang, Jingang

    2017-04-01

    The microseepage of natural gas from subsurface hydrocarbon reservoirs is a widespread process in petroleum basins. On a global scale, microseepage represents an important natural source of atmospheric methane (CH4). To date, microseepage CH4 flux data have been obtained from 20 petroleum systems in North America, Europe, and Asia. While the seasonal variations of gas flux due to soil methanotrophic activity are known, the role of geological factors in controlling gas fluxes has been poorly investigated. Here we present new microseepage data from the Dawanqi oil-gas field located within the Tarim Basin (China), a petroleum system characterized by intense faulting and shallow (thermogenic, like that occurring within the Dawanqi reservoirs, as demonstrated by 13C enrichment (δ13C from -46.3‰ to -30.7‰) in the chamber. Mean and range microseepage values (17 mg m-2d-1; from -1.4 to 330 mg m-2d-1) are similar to those reported for other petroleum fields with active tectonics. Our results confirm that dry soil over petroleum fields can be a net source of atmospheric CH4 and its flux is primarily controlled by faulting, and reservoir depth and pressure. These factors shall be considered in global bottom-up seepage emission estimates.

  5. Methylotrophic methanogenesis governs the biogenic coal bed methane formation in Eastern Ordos Basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hongguang; Yu, Zhisheng; Liu, Ruyin [Graduate Univ. of Chinese Academy of Sciences, Beijing (China). College of Resources and Environment; Zhang, Hongxun [Graduate Univ. of Chinese Academy of Sciences, Beijing (China). College of Resources and Environment; Chinese Academy of Sciences, Beijing (China). Research Center for Eco-Environmental Sciences; Zhong, Qiding; Xiong, Zhenghe [China National Research Institute of Food and Fermentation Industries, Beijing (China). Food Analysis using Isotope Technology Lab

    2012-12-15

    To identify the methanogenic pathways present in a deep coal bed methane (CBM) reservoir associated with Eastern Ordos Basin in China, a series of geochemical and microbiological studies was performed using gas and water samples produced from the Liulin CBM reservoir. The composition and stable isotopic ratios of CBM implied a mixed biogenic and thermogenic origin of the methane. Archaeal 16S rRNA gene analysis revealed the dominance of the methylotrophic methanogen Methanolobus in the water produced. The high potential of methane production by methylotrophic methanogens was found in the enrichments using the water samples amended with methanol and incubated at 25 and 35 C. Methylotrophic methanogens were the dominant archaea in both enrichments as shown by polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). Bacterial 16S rRNA gene analysis revealed that fermentative, sulfate-reducing, and nitrate-reducing bacteria inhabiting the water produced were a factor in coal biodegradation to fuel methanogens. These results suggested that past and ongoing biodegradation of coal by methylotrophic methanogens and syntrophic bacteria, as well as thermogenic CBM production, contributed to the Liulin CBM reserves associated with the Eastern Ordos Basin. (orig.)

  6. Drought Characteristic Analysis Based on an Improved PDSI in the Wei River Basin of China

    Directory of Open Access Journals (Sweden)

    Lei Zou

    2017-03-01

    Full Text Available In this study, to improve the efficiency of the original Palmer Drought Severity Index (PDSI_original, we coupled the Soil and Water Assessment tool (SWAT and PDSI_original to construct a drought index called PDSI_SWAT. The constructed PDSI_SWAT is applied in the Wei River Basin (WRB of China during 1960–2012. The comparison of the PDSI_SWAT with four other commonly used drought indices reveals the effectiveness of the PDSI_SWAT in describing the drought propagation processes in WRB. The whole WRB exhibits a dry trend, with more significant trends in the northern, southeastern and western WRB than the remaining regions. Furthermore, the drought frequencies show that drought seems to occur more likely in the northern part than the southern part of WRB. The principle component analysis method based on the PDSI_SWAT reveals that the whole basin can be further divided into three distinct sub-regions with different drought variability, i.e., the northern, southeastern and western part. Additionally, these three sub-regions are also consistent with the spatial pattern of drought shown by the drought frequency. The wavelet transform analysis method indicates that the El Niño-Southern Oscillation (ENSO events have strong impacts on inducing droughts in the WRB. The results of this study could be beneficial for a scientific water resources management and drought assessment in the current study area and also provide a valuable reference for other areas with similar climatic characteristics.

  7. Luminescence dating of the Zeketai loess section in the Ili Basin, northwestern China: Methodological considerations

    Science.gov (United States)

    Qin, Jintang; Zhou, Liping

    2018-04-01

    Loess deposits in Xinjiang, northwestern China are ideal archives for past environmental changes in the Westerlies-dominated central Asia. Among previous luminescence dating studies of loess in Xinjiang, few have attempted to systematically investigate the methodological aspects. In this study, we report results of a multiple-procedure luminescence dating of the Zeketai loess section in the Ili Basin, central Xinjiang. Optically stimulated luminescence (OSL) and post-infrared infrared stimulated luminescence (pIRIR) signals were used for quartz and polymineral grains of different sizes. The pIRIR ages obtained with two protocols agree well with each other and constrain the loess deposition between 50 ka and 88 ka. The OSL ages of fine-grained quartz are in stratigraphic order and range from 37 ka to 61 ka, but are ∼30% younger than the pIRIR295 ages of both fine and medium grained polyminerals. Although the causes of the discrepancy between the ages derived from different luminescence dating protocols are still to be understood, we stress that the quartz OSL ages of loess in this region are likely to be underestimated, especially for samples older than 40 ka. The polymineral or potassium feldspar pIRIR signal is recommended for dating loess in the Ili Basin, at least as an internal check.

  8. Deltaic Depositional Systems, Evolution Characteristics, and Petroleum Potential, Palaeogene Sub-Basin, South China Sea

    Science.gov (United States)

    Li, Yuan; Wang, Hua; Zhang, Guotao

    2015-04-01

    Deltaic depositional systems are detailed characterized by morphology and facies in a Palaeogene continental sub-basin of Beibuwan Basin, South China Sea. Based on examination of 435 m of conventional cores from 30 wells, three major types of deltaic facies have been recognized: delta, beach and shoreface. Morphology and facies asymmetry between the down-drift and the up-drift sides present a typical asymmetric delta system:1) the down-rift, sourced primarily by the feeding river, are influenced by mixed river and wave processes. Deposits on this side are muddy and consist of barrier, bar, bay-fill, and bayhead delta facies with variable bioturbation intensity; 2)the up-rift, in contrast, is sourced by a second sediment source and typically consists of laterally continuous sandy beach and shoreface facies. Finally, two fundamentally different depositional models are established and reflect a different style of sequence stratigraphic patterns: 1) Multiple-stage faults slopes developed in the down-rift side feed fine grained sediment into two stages channelized front deltaic system; 2) Flexure slope break of the up-rift side, combining with deeper gradual slopes, conversely, feed coarser grained sediment from larger drainages into sandy beach and shoreface systems. Such a distinction has well explained the differentiation of the proven hydrocarbon reserves because the up-rift consists of well-sorted, mature, and laterally continuous homogeneous beach-shoreface reservoirs, whereas the down-rift, in contrast, is muddier and consists of less continuous, less mature, heterolithic reservoirs. The Delta asymmetry concepts and models don't only challenge the traditional definition of deltas in Fushan sub-basin, but also provides strong theoretical support for the future exploration. This process-based model may be applicable to many deep-water settings and provides a framework within which to interpret the stratigraphic and spatial distribution of these complex deposits.

  9. The distribution of antibiotics in water of a river basin in South China

    Science.gov (United States)

    Meng, T.; Cheng, W.; Wang, M.; Wan, T.; Cheng, M.; Zhang, C. C.; Jia, Z. Y.

    2017-08-01

    In water environment field, one of the most attractive research topics is the determination of contamination characteristics of antibiotics in water. In order to investigate the distribution of antibiotics in surface water and drinking water of a certain river basin in southern China, we determined the types and concentrations of antibiotics that contaminated the river by performing HPLC-ESI-MS/MS method. Thus, we detected 17 antibiotics in four surface water samples (B1, B2, B3, and B4). In sampling points B3 and B4, we detected 16 antibiotics separately. The detection rates of norfloxacin, ofloxacin, and erythromycin-H2O were 100%, and the antibiotic erythromycin-H2O had the maximum concentration. In six drinking water samples (A1, A2, A3, A4, A5, and A6), we detected 13 antibiotics. In A5 water samples, we detected all the 13 antibiotics. The detection rate of ofloxacin and erythromycin-H2O was 100%, and erythromycin-H2O was the antibiotic with the highest concentration. We also found that from the upstream to the downstream of the river basin, the types of antibiotics in river increased gradually. In the upstream water samples (B1), we detected three antibiotics. Erythromycin-H2O was the antibiotic with the highest concentration of 6.61 ng/L, and sulfapyridine had the lowest concentration of 2.82 ng/L. In the downstream water samples (B4), we detected 16 antibiotics. Erythromycin-H2O was the antibiotic with the highest concentration of 277.58 ng/L, and the Sulfamonomethoxine was the antibiotic with the second-highest concentration of 242.1 ng/L. In addition, different membrane treatment processes could remove different amounts of antibiotics from the water samples. The study is an important reference for providing environmental protection to river water basin.

  10. Simulations of organic aerosol concentrations during springtime in the Guanzhong Basin, China

    Directory of Open Access Journals (Sweden)

    T. Feng

    2016-08-01

    Full Text Available The organic aerosol (OA concentration is simulated in the Guanzhong Basin, China from 23 to 25 April 2013 utilizing the WRF-CHEM model. Two approaches are used to predict OA concentrations: (1 a traditional secondary organic aerosol (SOA module; (2 a non-traditional SOA module including the volatility basis-set modeling method in which primary organic aerosol (POA is assumed to be semivolatile and photochemically reactive. Generally, the spatial patterns and temporal variations of the calculated hourly near-surface ozone and fine particle matters agree well with the observations in Xi'an and surrounding areas. The model also yields reasonable distributions of daily PM2.5 and elemental carbon (EC compared to the filter measurements at 29 sites in the basin. Filter-measured organic carbon (OC and EC are used to evaluate OA, POA, and SOA using the OC ∕ EC ratio approach. Compared with the traditional SOA module, the non-traditional module significantly improves SOA simulations and explains about 88 % of the observed SOA concentration. Oxidation and partitioning of POA treated as semivolatile constitute the most important pathway for the SOA formation, contributing more than 75 % of the SOA concentrations in the basin. Residential emissions are the dominant anthropogenic OA source, constituting about 50 % of OA concentrations in urban and rural areas and 30 % in the background area. The OA contribution from transportation emissions decreases from 25 % in urban areas to 20 % in the background area, and the industry emission OA contribution is less than 6 %.

  11. Changes in Remotely Sensed Vegetation Growth Trend in the Heihe Basin of Arid Northwestern China.

    Directory of Open Access Journals (Sweden)

    Wenchao Sun

    Full Text Available The Heihe River Basin (HRB is the second largest inland river basin in China, characterized by high diversity in geomorphology and irrigated agriculture in middle reaches. To improve the knowledge about the relationship between biotic and hydrological processes, this study used Global Inventory Modeling and Mapping Studies Normalized Difference Vegetation Index (NDVI data (1982-2006 to analyze spatiotemporal variations in vegetation growth by using the Mann-Kendall test together with Sen's slope estimator. The results indicate that 10.1% and 1.6% of basin area exhibit statistically significant (p < 0.05 upward and downward trends, and maximum magnitude is 0.066/10a and 0.026/10a, respectively. More specifically, an increasing trend was observed in the Qilian Mountains and Hexi Corridor and a decreasing trend detected in the transitional region between them. Increases in precipitation and temperature may be one possible reason for the changes of vegetation growth in the Qilian Mountains. And decreasing trend in transitional region may be driven by the changes in precipitation. Increases of irrigation contribute to the upward trend of NDVI for cropland in the Hexi Corridor, reflecting that agricultural development becomes more intensive. Our study demonstrates the complexity of the response of vegetation growth in the HRB to climate change and anthropogenic activities and correspondingly adopting mechanistic ecological models capable of describing both factors is favorable for reasonable predictions of future vegetation growth. It is also indicated that improving irrigation water use efficiency is one practical strategy to balance water demand between human and natural ecosystems in the HRB.

  12. Modeling of soil erosion and sediment transport in the East River Basin in southern China

    Science.gov (United States)

    Wu, Yping; Chen, Ji

    2012-01-01

    Soil erosion is a major global environmental problem that has caused many issues involving land degradation, sedimentation of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and sediment transport along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical sediment transport method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating sediment transport process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low sediment concentrations along the river. We also found that the East River is mainly characterized by sediment deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in sediment modeling for other basins worldwide.

  13. Previously unrecognized ornithuromorph bird diversity in the Early Cretaceous Changma Basin, Gansu Province, northwestern China.

    Science.gov (United States)

    Wang, Ya-Ming; O'Connor, Jingmai K; Li, Da-Qing; You, Hai-Lu

    2013-01-01

    Here we report on three new species of ornithuromorph birds from the Lower Cretaceous Xiagou Formation in the Changma Basin of Gansu Province, northwestern China: Yumenornis huangi gen. et sp. nov., Changmaornis houi gen. et sp. nov., and Jiuquanornis niui gen. et sp. nov.. The last of these is based on a previously published but unnamed specimen: GSGM-05-CM-021. Although incomplete, the specimens can be clearly distinguished from each other and from Gansus yumenensis Hou and Liu, 1984. Phylogenetic analysis resolves the three new taxa as basal ornithuromorphs. This study reveals previously unrecognized ornithuromorph diversity in the Changma avifauna, which is largely dominated by Gansus but with at least three other ornithuromorphs. Body mass estimates demonstrate that enantiornithines were much smaller than ornithuromorphs in the Changma avifauna. In addition, Changma enantiornithines preserve long and recurved pedal unguals, suggesting an arboreal lifestyle; in contrast, Changma ornithuromorphs tend to show terrestrial or even aquatic adaptions. Similar differences in body mass and ecology are also observed in the Jehol avifauna in northeastern China, suggesting niche partitioning between these two clades developed early in their evolutionary history.

  14. Previously Unrecognized Ornithuromorph Bird Diversity in the Early Cretaceous Changma Basin, Gansu Province, Northwestern China

    Science.gov (United States)

    Wang, Ya-Ming; O'Connor, Jingmai K.; Li, Da-Qing; You, Hai-Lu

    2013-01-01

    Here we report on three new species of ornithuromorph birds from the Lower Cretaceous Xiagou Formation in the Changma Basin of Gansu Province, northwestern China: Yumenornis huangi gen. et sp. nov., Changmaornis houi gen. et sp. nov., and Jiuquanornis niui gen. et sp. nov.. The last of these is based on a previously published but unnamed specimen: GSGM-05-CM-021. Although incomplete, the specimens can be clearly distinguished from each other and from Gansus yumenensis Hou and Liu, 1984. Phylogenetic analysis resolves the three new taxa as basal ornithuromorphs. This study reveals previously unrecognized ornithuromorph diversity in the Changma avifauna, which is largely dominated by Gansus but with at least three other ornithuromorphs. Body mass estimates demonstrate that enantiornithines were much smaller than ornithuromorphs in the Changma avifauna. In addition, Changma enantiornithines preserve long and recurved pedal unguals, suggesting an arboreal lifestyle; in contrast, Changma ornithuromorphs tend to show terrestrial or even aquatic adaptions. Similar differences in body mass and ecology are also observed in the Jehol avifauna in northeastern China, suggesting niche partitioning between these two clades developed early in their evolutionary history. PMID:24147058

  15. Assessment of the hydrogeochemistry and groundwater quality of the Tarim River Basin in an extreme arid region, NW China.

    Science.gov (United States)

    Xiao, Jun; Jin, Zhangdong; Wang, Jin

    2014-01-01

    The concentrations of the major and trace elements in the groundwater of the Tarim River Basin (TRB), the largest inland river basin of China, were analyzed before and during rainy seasons to determine the hydrogeochemistry and to assess the groundwater quality for irrigation and drinking purposes. The groundwater within the TRB was slightly alkaline and characterized by high ionic concentrations. The groundwater in the northern sub-basin was fresh water with a Ca(2+)-HCO3(-) water type, whereas the groundwater in the southern and central sub-basins was brackish with a Na(+)-Cl(-) water type. Evaporite dissolution and carbonate weathering were the primary and secondary sources of solutes in the groundwater within the basin, whereas silicate weathering played a minor role. The sodium adsorption ratio (SAR), water quality index (WQI), and sodium percentage (%Na) indicated that the groundwater in the northern sub-basin was suitable for irrigation and drinking, but that in the southern and central sub-basins was not suitable. The groundwater quality was slightly better in the wet season than in the dry season. The groundwater could be used for drinking after treatment for B(3+), F(-), and SO4(2-) and for irrigation after control of the sodium and salinity hazards. Considering the high corrosivity ratio of the groundwater in this area, noncorrosive pipes should be used for the groundwater supply. For sustainable development, integrated management of the surface water and the groundwater is needed in the future.

  16. Relationship between ancient bridges and population dynamics in the lower Yangtze River Basin, China.

    Science.gov (United States)

    Zhao, Yang; Jia, Xin; Lee, Harry F; Zhao, Hongqiang; Cai, Shuliang; Huang, Xianjin

    2017-01-01

    It has been suggested that population growth dynamics may be revealed by the geographic distribution and the physical structure of ancient bridges. Yet, this relationship has not been empirically verified. In this study, we applied the archaeological records for ancient bridges to reveal the population growth dynamics in the lower Yangtze River Basin in late imperial China. We investigated 89 ancient bridges in Yixing that were built during the Ming and Qing dynasties (AD1368-1911). Global Position System information and structure (length, width, and span) of those bridges was measured during our field investigations. Their distribution density was calculated by ArcGIS. The historical socio-economic dynamics of Yixing was inferred from the distribution and structure of ancient bridges. Based on the above information, the population growth dynamics in Yixing was projected. Our results show that 77 bridges were built in Yixing during the Qing dynasty, which is 6.41 times more than the number built during the Ming dynasty. In the Ming dynasty, bridges were built on pivotal routes; in the Qing dynasty, bridges were scattered across various places. Over the period, the density distribution of bridges shifted northwestward, while the average length and width of bridges decreased. The increasing number of bridges corresponded to population growth, largely attributable to massive clan migration from northern China during the Little Ice Age. The shift in the density distribution of bridges corresponded to the formation of settlements of large clans and the blossoming of Yixing Teapot handicrafts. The scattering and the reduction in average length and width of bridges was due to the dispersal of population and the associated formation of small settlements in the latter period. Our approach is innovative and robust, and could be employed to recover long-term historical population growth dynamics in other parts of China.

  17. Vegetation Carbon Storage, Spatial Patterns and Response to Altitude in Lancang River Basin, Southwest China

    Directory of Open Access Journals (Sweden)

    Long Chen

    2016-01-01

    Full Text Available Vegetation plays a very important role of carbon (C sinks in the global C cycle. With its complex terrain and diverse vegetation types, the Lancang River Basin (LRB of southwest China has huge C storage capacity. Therefore, understanding the spatial variations and controlling mechanisms of vegetation C storage is important to understand the regional C cycle. In this study, data from a forest inventory and field plots were used to estimate and map vegetation C storage distribution in the LRB, to qualify the quantitative relationships between vegetation C density and altitude at sublot and township scale, and a linear model or polynomial model was used to identify the relationship between C density and altitude at two spatial scales and two statistical scales. The results showed that a total of 300.32 Tg C was stored in the LRB, an important C sink in China. The majority of C storage was contributed by forests, notably oaks. The vegetation C storage exhibited nonlinear variation with latitudinal gradients. Altitude had tremendous influences on spatial patterns of vegetation C storage of three geomorphological types in the LRB. C storage decreased with increasing altitude at both town and sublot scales in the flat river valley (FRV region and the mid-low mountains gorge (MMG region, and first increased then decreased in the alpine gorge (AG region. This revealed that, in southwest China, altitude changes the latitudinal patterns of vegetation C storage; especially in the AG area, C density in the mid-altitude (3100 m area was higher than that of adjacent areas.

  18. Relationship between ancient bridges and population dynamics in the lower Yangtze River Basin, China.

    Directory of Open Access Journals (Sweden)

    Yang Zhao

    Full Text Available It has been suggested that population growth dynamics may be revealed by the geographic distribution and the physical structure of ancient bridges. Yet, this relationship has not been empirically verified. In this study, we applied the archaeological records for ancient bridges to reveal the population growth dynamics in the lower Yangtze River Basin in late imperial China. We investigated 89 ancient bridges in Yixing that were built during the Ming and Qing dynasties (AD1368-1911. Global Position System information and structure (length, width, and span of those bridges was measured during our field investigations. Their distribution density was calculated by ArcGIS. The historical socio-economic dynamics of Yixing was inferred from the distribution and structure of ancient bridges. Based on the above information, the population growth dynamics in Yixing was projected. Our results show that 77 bridges were built in Yixing during the Qing dynasty, which is 6.41 times more than the number built during the Ming dynasty. In the Ming dynasty, bridges were built on pivotal routes; in the Qing dynasty, bridges were scattered across various places. Over the period, the density distribution of bridges shifted northwestward, while the average length and width of bridges decreased. The increasing number of bridges corresponded to population growth, largely attributable to massive clan migration from northern China during the Little Ice Age. The shift in the density distribution of bridges corresponded to the formation of settlements of large clans and the blossoming of Yixing Teapot handicrafts. The scattering and the reduction in average length and width of bridges was due to the dispersal of population and the associated formation of small settlements in the latter period. Our approach is innovative and robust, and could be employed to recover long-term historical population growth dynamics in other parts of China.

  19. Relationship between ancient bridges and population dynamics in the lower Yangtze River Basin, China

    Science.gov (United States)

    Zhao, Yang; Lee, Harry F.; Zhao, Hongqiang; Cai, Shuliang; Huang, Xianjin

    2017-01-01

    It has been suggested that population growth dynamics may be revealed by the geographic distribution and the physical structure of ancient bridges. Yet, this relationship has not been empirically verified. In this study, we applied the archaeological records for ancient bridges to reveal the population growth dynamics in the lower Yangtze River Basin in late imperial China. We investigated 89 ancient bridges in Yixing that were built during the Ming and Qing dynasties (AD1368–1911). Global Position System information and structure (length, width, and span) of those bridges was measured during our field investigations. Their distribution density was calculated by ArcGIS. The historical socio-economic dynamics of Yixing was inferred from the distribution and structure of ancient bridges. Based on the above information, the population growth dynamics in Yixing was projected. Our results show that 77 bridges were built in Yixing during the Qing dynasty, which is 6.41 times more than the number built during the Ming dynasty. In the Ming dynasty, bridges were built on pivotal routes; in the Qing dynasty, bridges were scattered across various places. Over the period, the density distribution of bridges shifted northwestward, while the average length and width of bridges decreased. The increasing number of bridges corresponded to population growth, largely attributable to massive clan migration from northern China during the Little Ice Age. The shift in the density distribution of bridges corresponded to the formation of settlements of large clans and the blossoming of Yixing Teapot handicrafts. The scattering and the reduction in average length and width of bridges was due to the dispersal of population and the associated formation of small settlements in the latter period. Our approach is innovative and robust, and could be employed to recover long-term historical population growth dynamics in other parts of China. PMID:28792976

  20. Water quality variation in the highly disturbed Huai River Basin, China from 1994 to 2005 by multi-statistical analyses.

    Science.gov (United States)

    Zhai, Xiaoyan; Xia, Jun; Zhang, Yongyong

    2014-10-15

    Water quality deterioration is a prominent issue threatening water security throughout the world. Huai River Basin, as the sixth largest basin in China, is facing the most severe water pollution and high disturbance. Statistical detection of water quality trends and identification of human interferences are significant for sustainable water quality management. Three key water quality elements (ammonium nitrogen: NH3-N, permanganate index: CODMn and dissolved oxygen: DO) at 18 monitoring stations were selected to analyze their spatio-temporal variations in the highly disturbed Huai River Basin using seasonal Mann-Kendall test and Moran's I method. Relationship between surrounding water environment and anthropogenic activities (point source emission, land use) was investigated by regression analysis. The results indicated that water environment was significantly improved on the whole from 1994 to 2005. CODMn and NH3-N concentrations decreased at half of the stations, and DO concentration increased significantly at 39% (7/18) stations. The high pollution cluster centers for both NH3-N and CODMn were in the middle stream of Shaying River and Guo River in the 2000s. Water quality of Huai River Basin was mainly influenced by point source pollution emission, flows regulated by dams, water temperature and land use variations and so on. This study was expected to provide insights into water quality evolution and foundations for water quality management in Huai River Basin, and scientific references for the implementation of water pollution prevention in China. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Different scale land subsidence and ground fissure monitoring with multiple InSAR techniques over Fenwei basin, China

    Directory of Open Access Journals (Sweden)

    C. Zhao

    2015-11-01

    Full Text Available Fenwei basin, China, composed by several sub-basins, has been suffering severe geo-hazards in last 60 years, including large scale land subsidence and small scale ground fissure, which caused serious infrastructure damages and property losses. In this paper, we apply different InSAR techniques with different SAR data to monitor these hazards. Firstly, combined small baseline subset (SBAS InSAR method and persistent scatterers (PS InSAR method is used to multi-track Envisat ASAR data to retrieve the large scale land subsidence covering entire Fenwei basin, from which different land subsidence magnitudes are analyzed of different sub-basins. Secondly, PS-InSAR method is used to monitor the small scale ground fissure deformation in Yuncheng basin, where different spatial deformation gradient can be clearly discovered. Lastly, different track SAR data are contributed to retrieve two-dimensional deformation in both land subsidence and ground fissure region, Xi'an, China, which can be benefitial to explain the occurrence of ground fissure and the correlation between land subsidence and ground fissure.

  2. An evaluation of the effect of future climate on runoff in the Dongjiang River basin, South China

    Directory of Open Access Journals (Sweden)

    K. Lin

    2015-05-01

    Full Text Available The impact of future climate change on the runoff for the Dongjiang River basin, South China, has been investigated with the Soil and Water Assessment Tool (SWAT. First, the SWAT model was applied in the three sub-basins of the Dongjiang River basin, and calibrated for the period of 1970–1975, and validated for the period of 1976–1985. Then the hydrological response under climate change and land use scenario in the next 40 years (2011–2050 was studied. The future weather data was generated by using the weather generators of SWAT, based on the trend of the observed data series (1966–2005. The results showed that under the future climate change and LUCC scenario, the annual runoff of the three sub-basins all decreased. Its impacts on annual runoff were –6.87%, –6.54%, and –18.16% for the Shuntian, Lantang, and Yuecheng sub-basins respectively, compared with the baseline period 1966–2005. The results of this study could be a reference for regional water resources management since Dongjiang River provides crucial water supplies to Guangdong Province and the District of Hong Kong in China.

  3. Early to Middle Triassic sedimentary records in the Youjiang Basin, South China: Implications for Indosinian orogenesis

    Science.gov (United States)

    Qiu, Liang; Yan, Dan-Ping; Yang, Wen-Xin; Wang, Jibin; Tang, Xiangli; Ariser, Shahnawaz

    2017-06-01

    The Indosinian orogeny marks the termination of marine deposition and the accumulation of lower Permian to Late Triassic clastic sediments in the Youjiang Basin, South China Block. Major and trace element compositions of Early to Middle Triassic sedimentary clastic rocks from Youjiang Basin were analysed to constrain their provenance and tectonic setting. Argillaceous samples have low SiO2 (average 56.95 wt.%), Al2O3 (average 15.15 wt.%), and Fe2O3T + MgO (average 11.54 wt.%) contents, and high K2O/Na2O (average 15.61) and Al2O3/SiO2 (average 0.27) ratios, similar to mudstones from continental arc basins. Arenaceous samples have moderate SiO2 (average 76.98 wt.%), Al2O3 (average 8.41 wt.%), and Fe2O3T + MgO (average 5.29 wt.%) contents, and moderate Al2O3/SiO2 (average 0.11) and K2O/Na2O (average 15.26) ratios, identical to those of graywackes from continental island arcs or active continental margins. Both the argillaceous and arenaceous samples have low CIA values (57-85) and relatively high ICV values (0.69-2.11), indicating that the source rocks experienced weak chemical weathering and the sedimentary detritus was derived from an immature source. Compared with late Permian to Early Triassic South China granitoids and upper crust, the samples have lower contents of high-field-strength elements (e.g., Zr, Hf, Nb, and Ta) and large ion lithophile elements (e.g., Rb, Sr, Ba, Th, U, and Pb). However, their relatively high Rb concentrations (>51 ppm), and low Rb/Sr (0.16-4.19) and Th/U (2.66-5.21) ratios, are indicative of an igneous source from a continental arc that underwent weak chemical weathering. Both the argillaceous and arenaceous samples are moderately enriched in light rare earth elements and show relatively flat chondrite-normalized heavy rare earth element patterns (LaN/YbN = 6.61-17.35; average 10.61) with strong negative Eu anomalies (Eu/Eu* = 0.54-0.89; average 0.73). In tectonic discrimination diagrams, including Th-Sc-Zr/10 and La-Th-Sc plots, the

  4. Southernmost indications of large freshwater discharges during the Heinrich Stadials (Galicia Interior Basin, Northwest Iberian Continental Margin)

    Science.gov (United States)

    Plaza-Morlote, Maider; Rey, Daniel; Francisco Santos, Jose; Ribeiro, Sara; Heslop, David; Bernabeu, Ana M.; Mohamed, Kais J.; Rubio, Belen; Martins, Virginia

    2017-04-01

    The reconstruction of circum-Atlantic ice-sheet instabilities is of great importance to understanding the mechanisms that force abrupt climate changes. We have used enviromagnetic and geochemical data to explore these issues, providing a continuous and well-dated record of the evolution of glacial/interglacial sedimentation in the Galician Interior Basin (GIB) during the last glacial period covering the last six Heinrich Stadials. Our results show sediments of European provenance that have been related to meltwater pre-events during the initial stages of HS1, HS2, and HS4 corroborating the Channel River depositional history. Therefore, this study provides insight into one of the potential forcing mechanisms for Heinrich Events and, by inference, for Heinrich Stadials. The GIB records are an important element in the discussion of EIS-LIS-AMOC dynamics. Their significant distance from these ice-sheets is such that they have only recorded the most catastrophic ice shelves collapse events and/or meltwater discharges, acting as a low-amplitude filter to the interrelated dynamics and instabilities of the North Atlantic ice sheets. Our results demonstrate that European-sourced sediments arrived earlier at this site than Laurentide-sourced icebergs. This implies greater EIS freshwater discharges resulting from the deglacial activation of EIS palaeorivers for HS1 and from glacial instabilities during the course of the EIS' progression to its LGM position for HS2 and HS4. This supports the idea of synchronous collapse of the EIS and LIS. The data also suggest that these discharges acted as a positive feedback mechanism that further weakened the AMOC, accelerating LIS and EIS collapse.

  5. Human settlement and its influencing factors during the historicalperiod in an oasis-desert transition zone of Dunhuang, Hexi Corridor,northwest China

    Science.gov (United States)

    Li, H.; Dong, G.; Zhang, S.

    2017-12-01

    Many ancient cities and settlement sites have been found in Lucaogou, an ancient oasis near Dunhuangcity in northwest China. These settlements indicate that humans inhabited this area during the historicalperiod. However, the chronology and subsistence practices of this area remain unclear. Based on newdata from radiocarbon dating, macrobotanical analysis, and the synthesis of historical documents andhigh-resolution paleoclimatic records, we discuss the inter-relationship between human settlements andplant resource utilization strategies at Lucaogou ancient oasis during historical period. Our resultsindicate that these ancient sites in Lucaogou area were built between the Han dynasty (202 BC-AD 220)and the Ming dynasty (AD 1368-AD 1644). People mainly used foxtail millet, broomcorn millet, barleyand three types of wood (Tamarix, Salix, Populus), probably as fuel for cooking. Human settlement intensityin the area during the historical period was primarily influenced by political situations, whichmight also have been affected by fluctuations in precipitation.

  6. Dying for Money: The Effects of Global Health Initiatives on NGOs Working with Gay Men and HIV/AIDS in Northwest China.

    Science.gov (United States)

    Miller, Casey James

    2016-09-01

    Drawing on 17 months of ethnographic fieldwork (2007-2011), this article critically examines the consequences of two global health initiatives (GHIs), the Global Fund and the Gates Foundation, on NGOs engaged in HIV/AIDS prevention and treatment among gay men in northwest China. I argue that a short-term surge in funding provided by GHIs between 2008 and 2010 exacerbated preexisting conflicts between NGOs by promoting a neoliberal process in which the state outsourced public health services to civil society organizations, deliberately encouraging a climate of competition among NGOs. I also show how GHIs encouraged the bureaucratization and medicalization of one grassroots gay NGO, channeling its activities away from broader political and social objectives and compelling the group to develop a narrower and more entrepreneurial emphasis on HIV testing and treatment. This article contributes to a deeper ethnographic understanding of the complex and perhaps unintended consequences of GHIs. © 2016 by the American Anthropological Association.

  7. Lower Eocene alluvial paleosols (Willwood Formation, Northwest Wyoming, U.S.A.) and their significance for paleoecology, paleoclimatology, and basin analysis

    Science.gov (United States)

    Bown, Thomas M.; Kraus, M.J.

    1981-01-01

    The lower Eocene Willwood Formation of northwest Wyoming is a 700 m thick accumulation of alluvial floodplain and channel mudstones and sandstones, nearly all of which show paleopedogenic modifications. Pedogenesis of Willwood sandstones is indicated by taproot and vertebrate and invertebrate bioturbation, early local cementation by calcium carbonate, and thin illuviation cutans on clastic grains. Pedogenesis in Willwood mudstones is indicated by plant bioturbation, insect and other invertebrate burrow casts and lebensspuren; free iron, aluminum, and manganese mobilization, including hydromorphic gleying; sesquioxide and calcareous glaebule formation in lower parts of the solum; presence of clay-rich and organic carbon-rich zones; and well differentiated epipedons and albic and spodic horizons. Probable A horizons are also locally well developed.Occurrence of variegated paleosol units in thick floodplain mudstone deposits and their association with thin, lenticular, and unconnected fluvial sandstones in the Willwood Formation of the central and southeast Bighorn Basin suggest that these soils formed during times of rapid sediment accumulation. The tabular geometry and lateral persistence of soil units as well as the absence of catenization indicate that Willwood floodplains were broad and essentially featureless.All Willwood paleosols were developed on alluvial parent materials and are complex in that B horizons of younger paleosols were commonly superimposed upon and mask properties of suspected A and B horizons of the next older paleosols. The soils appear to be wet varieties of the Spodosol and Entisol groups (aquods and ferrods, and aquents, respectively), though thick, superposed and less mottled red, purple, and yellow paleosols resemble some ultisols. Most Willwood paleosols resemble warm temperate to subtropical alluvial soils that form today under alternating wet and dry conditions and (or) fluctuating water tables. The up-section decrease in frequency of

  8. Morphologies and depositional/erosional controls on evolution of Pliocene-Pleistocene carbonate platforms: Northern Carnarvon Basin, Northwest Shelf of Australia

    Science.gov (United States)

    Goktas, P.; Austin, J. A.; Fulthorpe, C. S.; Gallagher, S. J.

    2016-08-01

    The detailed morphologies, evolution and termination of latest Neogene tropical carbonate platforms in the Northern Carnarvon Basin (NCB), on the passive margin of the Northwest Shelf (NWS) of Australia, defined based upon mapping using 3D seismic images, reveal the history of local/regional oceanographic processes, fluctuations in relative sea-level and changing climate. Cool-water carbonate deposition, dominant during the early-middle Miocene, was followed by a siliciclastic influx, which prograded across the NWS beginning in the late-middle Miocene, during a period of long-term global sea-level fall. The resulting prograding clinoform sets, interpreted as delta lobes, created relict topographic highs following Pliocene termination of the siliciclastic influx. These highs constituted multiple favorable shallow-water environments for subsequent photozoan carbonate production. Resultant platform carbonate development, in addition to being a response to cessation of siliciclastic influx and the existence of suitable shallow-water substrate, was also influenced by development of the warm-water Leeuwin Current (LC), flowing southwestward along this margin. Four flat-topped platforms are mapped; each platform top is a sequence boundary defined by reflection onlap above and truncation below. Successive platforms migrated southwestward through time, along margin strike. All platforms exhibit predominantly progradational seismic geometries. Mapped tops are ≥10 km wide. Seismic evidence of karst on three of four platform tops, e.g., v-shaped troughs up to 50 m deep and ~1 km wide, and broader basins with areas up to 20 km2, suggests episodic subaerial exposure that may have contributed to platform demise. Platform 4, the most recent, is unique in having interpreted biohermal build-ups superimposed on the progradational platform base. The base of these interpreted patch reefs now lies at a water depth of ~153 m; therefore, we suggest that these reefs developed post

  9. Assessments of carbon and water cycling in multiple agricultural ecosystems in the Inland Pacific Northwest using eddy covariance flux measurements and integrated basin-crop model simulation

    Science.gov (United States)

    Chi, J.; Maureira, F.; Waldo, S.; O'Keeffe, P.; Pressley, S. N.; Stockle, C. O.; Lamb, B. K.

    2014-12-01

    Local meteorology, crop management practices and site characteristics have important impacts on carbon and water cycling in agricultural ecosystems. This study focuses on carbon and water fluxes measured using eddy covariance (EC) methods and crop simulation models in the Inland Pacific Northwest (IPNW), in association with the Regional Approaches to Climate Change (REACCH) program. The agricultural ecosystem is currently challenged by higher pressure on water resources as a consequence of population growth and increasing exposure to impacts associated with different types of crop managements. In addition, future climate projections for this region show a likely increase in temperature and significant reductions in precipitation that will affect carbon and water dynamics. This new scenario requires an understanding of crop management by assessing efficient ways to face the impacts of climate change at the micrometeorological level, especially in regards to carbon and water flow. We focus on three different crop management sites. One site (LIND) under crop-fallow is situated in a low-rainfall area. The other two sites, one no-till site (CAF-NT) and one conventional tillage site (CAF-CT), are located in an area of high-rainfall with continuous cropping. In this study, we used CropSyst micro-basin model to simulate the responses in carbon and water budgets at each site. Based on the EC processed results for net ecosystem exchange (NEE) of CO2, the CAF-NT site was a carbon sink during 2013 when spring garbanzo was planted; while the paired CAF-CT site, under similar crop rotation and meteorological conditions, was a carbon source during the same period. The LIND site was also a carbon sink where winter wheat was growing during 2013. Model results for CAF-NT showed good agreement with the EC carbon and water flux measurements during 2013. Through comparisons between measurements and modeling results, both short and long term processes that influence carbon and water

  10. Validation of the MODIS MOD21 and MOD11 land surface temperature and emissivity products in an arid area of Northwest China

    Science.gov (United States)

    Li, H.; Yang, Y.; Yongming, D.; Cao, B.; Qinhuo, L.

    2017-12-01

    Land surface temperature (LST) is a key parameter for hydrological, meteorological, climatological and environmental studies. During the past decades, many efforts have been devoted to the establishment of methodology for retrieving the LST from remote sensing data and significant progress has been achieved. Many operational LST products have been generated using different remote sensing data. MODIS LST product (MOD11) is one of the most commonly used LST products, which is produced using a generalized split-window algorithm. Many validation studies have showed that MOD11 LST product agrees well with ground measurements over vegetated and inland water surfaces, however, large negative biases of up to 5 K are present over arid regions. In addition, land surface emissivity of MOD11 are estimated by assigning fixed emissivities according to a land cover classification dataset, which may introduce large errors to the LST product due to misclassification of the land cover. Therefore, a new MODIS LSE&E product (MOD21) is developed based on the temperature emissivity separation (TES) algorithm, and the water vapor scaling (WVS) method has also been incorporated into the MODIS TES algorithm for improving the accuracy of the atmospheric correction. The MOD21 product will be released with MODIS collection 6 Tier-2 land products in 2017. Due to the MOD21 products are not available right now, the MODTES algorithm was implemented including the TES and WVS methods as detailed in the MOD21 Algorithm Theoretical Basis Document. The MOD21 and MOD11 C6 LST products are validated using ground measurements and ASTER LST products collected in an arid area of Northwest China during the Heihe Watershed Allied Telemetry Experimental Research (HiWATER) experiment. In addition, lab emissivity spectra of four sand dunes in the Northwest China are also used to validate the MOD21 and MOD11 emissivity products.

  11. Tectonic implications of Mesozoic magmatism to initiation of Cenozoic basin development within the passive South China Sea margin

    Science.gov (United States)

    Mai, Hue Anh; Chan, Yu Lu; Yeh, Meng Wan; Lee, Tung Yi

    2018-04-01

    The South China Sea (SCS) is one of the classical example of a non-volcanic passive margin situated within three tectonic plates of the Eurasian, Indo-Australian and Philippine Sea plate. The development of SCS resulted from interaction of various types of plate boundaries, and complex tectonic assemblage of micro blocks and accretionary prisms. Numerous models were proposed for the formation of SCS, yet none can fully satisfy different aspects of tectonic forces. Temporal and geographical reconstruction of Cretaceous and Cenozoic magmatism with the isochrones of major basins was conducted. Our reconstruction indicated the SE margin of Asia had gone through two crustal thinning events. The sites for rifting development are controlled by localized thermal weakening of magmatism. NW-SE extension setting during Late Cretaceous revealed by magmatism distribution and sedimentary basins allow us to allocate the retreated subduction of Pacific plate to the cause of first crustal thinning event. A magmatic gap between 75 and 65 Ma prior to the initiation of first basin rifting suggested a significant modification of geodynamic setting occurred. The Tainan basin, Pearl River Mouth basin, and Liyue basins started to develop since 65 Ma where the youngest Late Cretaceous magmatism concentrated. Sporadic bimodal volcanism between 65 and 40 Ma indicates further continental extension prior to the opening of SCS. The E-W extension of Malay basin and West Natuna began since late Eocene followed by N-S rifting of SCS as Neotethys subducted. The SCS ridge developed between Pearl River Mouth basin and Liyue basin where 40 Ma volcanic activities concentrated. The interaction of two continental stretching events by Pacific followed by Neotethys subduction with localized magmatic thermal weakening is the cause for the non-volcanic nature of SCS.

  12. Objective Tracking of Tropical Cyclones in the North-West Pacific Basin Based on Wind Field Information only

    Science.gov (United States)

    Leckebusch, G. C.; Befort, D. J.; Kruschke, T.

    2016-12-01

    Although only ca. 12% of the global insured losses of natural disasters occurred in Asia, there are two major reasons to be concerned about risks in Asia: a) The fraction of loss events was substantial higher with 39% of which 94% were due to atmospheric processes; b) Asia and especially China, is undergoing quick transitions and especially the insurance market is rapidly growing. In order to allow for the estimation of potential future (loss) impacts in East-Asia, in this study we further developed and applied a feature tracking system based on extreme wind speed occurrences to tropical cyclones, which was originally developed for extra-tropical cyclones (Leckebusch et al., 2008). In principle, wind fields will be identified and tracked once a coherent exceedance of local percentile thresholds is identified. The focus on severe wind impact will allow an objective link between the strength of a cyclone and its potential damages over land. The wind tracking is developed in such a way to be applicable also to course-gridded AOGCM simulation. In the presented configuration the wind tracking algorithm is applied to the Japanese reanalysis (JRA55) and TC Identification is based on 850hPa wind speeds (6h resolution) from 1979 to 2014 over the Western North Pacific region. For validation the IBTrACS Best Track archive version v03r8 is used. Out of all 904 observed tracks, about 62% can be matched to at least one windstorm event identified in JRA55. It is found that the relative amount of matched best tracks increases with the maximum intensity. Thus, a positive matching (hit rate) of above 98% for Violent Typhoons (VTY), above 90% for Very Strong Typhoons (VSTY), about 75% for Typhoons (TY), and still some 50% for less intense TCs (TD, TS, STS) is found. This result is extremely encouraging to apply this technique to AOGCM outputs and to derive information about affected regions and intensity-frequency distributions potentially changed under future climate conditions.

  13. New insights into the distribution and evolution of the Cenozoic Tan-Lu Fault Zone in the Liaohe sub-basin of the Bohai Bay Basin, eastern China

    Science.gov (United States)

    Huang, Lei; Liu, Chi-yang; Xu, Chang-gui; Wu, Kui; Wang, Guang-yuan; Jia, Nan

    2018-01-01

    As the largest strike-slip fault system in eastern China, the northeast-trending Tan-Lu Fault Zone (TLFZ) is a significant tectonic element contributing to the Mesozoic-Cenozoic regional geologic evolution of eastern Asia, as well as to the formation of ore deposits and oilfields. Because of the paucity of data, its distribution and evolutionary history in the offshore Liaohe sub-basin of the northern Bohai Bay Basin (BBB) are still poorly understood. Investigations of the strike-slip fault system in the western portion of the offshore Liaohe sub-basin via new seismic data provide us with new insights into the characteristics of the Cenozoic TLFZ. Results of this study show that Cenozoic dextral strike-slip faults occurred near the center of the Liaoxi graben in the offshore Liaohe sub-basin; these strike-slip faults connect with their counterparts to the north, the western part of the onshore Liaohe sub-basin, and have similar characteristics to those in other areas of the BBB in terms of kinematics, evolutionary history, and distribution; consequently, these faults are considered as the western branch of the TLFZ. All strike-slip faults within the Liaoxi graben merge at depth with a central subvertical basement fault induced by the reactivation of a pre-existing strike-slip basement fault, the pre-Cenozoic TLFZ. Data suggest that the TLFZ across the whole Liaohe sub-basin comprises two branches and that the Cenozoic distribution of this system was inherited from the pre-Cenozoic TLFZ. This characteristic distribution might be possessed by the whole TLFZ, thus the new understandings about the distribution and evolutionary model of the TLFZ in this study can be inferred in many research fields along the whole fault zone, such as regional geology, ore deposits, petroleum exploration and earthquake hazard.

  14. Lacustrine fan delta deposition alongside intrabasinal structural highs in rift basins: an example from the Early Cretaceous Jiuquan Basin, Northwestern China

    Science.gov (United States)

    Zhang, Chengcheng; Muirhead, James D.; Wang, Hua; Chen, Si; Liao, Yuantao; Lu, Zongsheng; Wei, Jun

    2018-01-01

    Development of fan deltas alongside intrabasinal structural highs has been overlooked compared to those forming on basin margins. However, these fan deltas may provide important clues regarding the tectonic and climatic controls on deposition during rift development. This paper documents fan delta deposition alongside an intrabasinal structural high within the Early Cretaceous Xiagou Formation of the Jiuquan Basin, China, using subsurface geological and geophysical data. Deposits observed in drill core support fan delta deposition occurring almost exclusively through subaerial and subaqueous gravity flows. Subsurface mapping reveals a consistent decrease in the areal extent of fan deltas from lowstand to highstand system tracts, suggesting that deposition alongside the structural high is sensitive to lake-level changes. The temporal and spatial distribution of the fan deltas display retrogradational stacking patterns, where fan deltas exhibit a decreasing lateral extent up-sequence until fan delta deposition terminated and was replaced by deposition of fine-grained lacustrine deposits. The retrogradational stacking patterns observed alongside the intrabasinal structural high are not observed in fan deltas along the basin margin in the lower parts of the Xiagou Formation. Subsidence profiles also show differential subsidence across the basin during the earliest stages of this formation, likely resulting from border fault movements. These data suggest that non-uniform stacking patterns in the lower parts of the Xiagou Formation reflect basin-scale tectonic movements as the dominant control on synrift deposition patterns. However, later stages of Xiagou Formation deposition were characterized by uniform subsidence across the basin, and uniform retrogradational stacking patterns for fan deltas alongside the intrabasinal structural high and border fault. These observations suggest that basin-scale tectonic movements played a relatively limited role in controlling

  15. Using integrated multivariate statistics to assess the hydrochemistry of surface water quality, Lake Taihu basin, China

    Directory of Open Access Journals (Sweden)

    Xiangyu Mu

    2014-09-01

    Full Text Available Natural factors and anthropogenic activities both contribute dissolved chemical loads to  lakes and streams.  Mineral solubility,  geomorphology of the drainage basin, source strengths and climate all contribute to concentrations and their variability. Urbanization and agriculture waste-water particularly lead to aquatic environmental degradation. Major contaminant sources and controls on water quality can be asssessed by analyzing the variability in proportions of major and minor solutes in water coupled to mutivariate statistical methods.   The demand for freshwater needed for increasing crop production puulation and industrialization occurs almost everywhere in in China and these conflicting needs have led to widespread water contamination. Because of heavy nutrient loadings from all of these sources, Lake Taihu (eastern China notably suffers periodic hyper-eutrophication and drinking water deterioration, which has led to shortages of freshwater for the City of Wuxi and other nearby cities. This lake, the third largest freshwater body in China, has historically beeen considered a cultural treasure of China, and has supported long-term fisheries. The is increasing pressure to remediate the present contamination which compromises both aquiculture and the prior economic base centered on tourism.  However, remediation cannot be effectively done without first characterizing the broad nature of the non-point source pollution. To this end, we investigated the hydrochemical setting of Lake Taihu to determine how different land use types influence the variability of surface water chemistry in different water sources to the lake. We found that waters broadly show wide variability ranging from  calcium-magnesium-bicarbonate hydrochemical facies type to mixed sodium-sulfate-chloride type. Principal components analysis produced three principal components that explained 78% of the variance in the water quality and reflect three major types of water

  16. Do fine-grained components of loess indicate westerlies: Insights from observations of dust storm deposits at Lenghu (Qaidam Basin, China)

    OpenAIRE

    M. Qiang; L. Lang; Z. Wang;  

    2010-01-01

    The hyper-arid Qaidam Basin is a major dust source area in China. Mineral materials that settled during 11 dust storms from November 2003 to April 2005 in the northern Qaidam Basin were comprised of an amount of fine particles. The particles

  17. A detrital record of continent-continent collision in the Early-Middle Jurassic foreland sequence in the northern Yangtze foreland basin, South China

    Science.gov (United States)

    Qian, Tao; Liu, Shaofeng; Wang, Zongxiu; Li, Wangpeng; Chen, Xinlu

    2016-12-01

    The Mesozoic northern Yangtze foreland basin system was formed by continental collision between the North China and South China plates along the Mianlue suture. Synorogenic stratigraphic sequences of Late Triassic to Early-Middle Jurassic age were developed in the northern Yangtze foreland basin. The upper Middle Jurassic Shaximiao Formation consists mainly of thick-bedded terrestrial successions that serve as the main body of the basin-filling sequences, suggesting intense tectonism in the peripheral orogeny of the foreland basin. Laser-ICP-MS U-Pb analysis of 254 detrital zircon grains from sandstone samples and several published Lower-Middle Jurassic samples, detrital compositions, petrofacies, and paleocurrent reconstructions in the northern Yangtze foreland basin indicate that discrete source areas included the Qinling-Dabieshan ranges and the Mianlue suture zone to the north, and the South China plate to the south. The stratigraphic succession and sediment provenance of the foreland basin imply that the early Mianlue oceanic basin, magmatic arc, and nonmarine molasse foreland basin during the period of deposition were modified or buried by the subsequent continent-continent collision between the North China-Qinling-Dabieshan plate and the Yangtze plate during the Jurassic, which followed the oblique amalgamation between these plates during the Middle-Late Triassic.

  18. Accumulation conditions and exploration potential of Wufeng-Longmaxi Formations shale gas in Wuxi area, Northeastern Sichuan Basin, China

    OpenAIRE

    Wei Wu; Xuewen Shi; Jia Liu; Du Li; Jun Xie; Shengxian Zhao; Chunhai Ji; Ying Hu; Yanbo Guo

    2017-01-01

    Wufeng-Longmaxi Formations shale gas is a new exploration field in Wuxi area, Sichuan Basin, China. Some geological parameters related to shale gas evaluation of the new exploration wells in Wuxi area have been studied, including shale reservoir, gas-bearing, geochemical and paleontological characteristics. The study suggests that the original shale gas generation conditions of the area were good, but later this area went through serious and multi-phase tectonic damage. The major evidences in...

  19. Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Kang Xu

    2015-09-01

    Full Text Available Oil and gas exploration in carbonate rocks was extremely successful in recent years in the Ordovician in Tarim Basin, NW China. Here, we investigate the carbonate reservoirs in the Bachu area of the Tarim Basin through petrological and geochemical studies combined with oil and gas exploration data. Geochemical analysis included the major, trace, and rare earth elements; fluid inclusion thermometry; clay mineral characterization; and carbon and oxygen isotopes of the carbonate rocks. Homogenization temperatures of the fluid inclusions of Well He-3 in the Bachu area indicate three groups, 60–80 °C, 90–130 °C, and 140–170 °C, and suggest that the carbonate rocks experienced modification due to heating events. The porosity in the reservoir is defined by fractures and secondary pores, and there is a notable increase in the porosity of the carbonate reservoirs in proximity to magmatic intrusion, particularly approximately 8–10 m from the intrusive rocks. The development of secondary pores was controlled by lithofacies and corrosion by various fluids. We identify supercritical fluids with high density (138.12–143.97 mg/cm3 in the Bachu area. The negative correlations of δ13C (−2.76‰ to −0.97‰ and δ18O (−7.91‰ to −5.07‰ suggest that the carbonate rocks in the study area were modified by high-salinity hydrothermal fluid. The formation of clay minerals, such as illite and montmorillonite, caused a decrease in porosity. Our study demonstrates the effect of magmatic intrusions in modifying the reservoir characteristics of carbonate rocks and has important implications for oil and gas exploration.

  20. Mid-Neolithic Exploitation of Mollusks in the Guanzhong Basin of Northwestern China: Preliminary Results

    Science.gov (United States)

    Li, Fengjiang; Wu, Naiqin; Lu, Houyuan; Zhang, Jianping; Wang, Weilin; Ma, Mingzhi; Zhang, Xiaohu; Yang, Xiaoyan

    2013-01-01

    Mollusk remains are abundant in archaeological sites in the Guanzhong Basin of Northwestern China, providing good opportunities for investigations into the use of mollusks by prehistoric humans. Here we report on freshwater gastropod and bivalve mollusks covering the time interval from about 5600 to 4500 cal. yrs BP from sites of Mid-Late Neolithic age. They are identified as Cipangopaludina chinensis and Unio douglasiae, both of which are currently food for humans. The shells are well preserved and have no signs of abrasion. They are all freshwater gastropods and bivalves found in pits without water-reworked deposits and have modern representatives which can be observed in rivers, reservoirs, and paddy fields in the studied region. Mollusk shells were frequently recovered in association with mammal bones, lithic artifacts, and pottery. These lines of evidence indicate that the mollusks are the remains of prehistoric meals. The mollusk shells were likely discarded into the pits by prehistoric humans after the flesh was eaten. However, these mollusk remains may not have been staple food since they are not found in large quantities. Mollusk shell tools and ornaments are also observed. Shell tools include shell knives, shell reaphooks and arrowheads, whereas shell ornaments are composed of pendants and loops. All the shell tools and ornaments are made of bivalve mollusks and do not occur in large numbers. The finding of these freshwater mollusk remains supports the view that the middle Holocene climate in the Guanzhong Basin may have been warm and moist, which was probably favorable to freshwater mollusks growing and developing in the region. PMID:23544050

  1. Evaluation on uncertainty sources in projecting hydrological changes over the Xijiang River basin in South China

    Science.gov (United States)

    Yuan, Fei; Zhao, Chongxu; Jiang, Yong; Ren, Liliang; Shan, Hongcui; Zhang, Limin; Zhu, Yonghua; Chen, Tao; Jiang, Shanhu; Yang, Xiaoli; Shen, Hongren

    2017-11-01

    Projections of hydrological changes are associated with large uncertainties from different sources, which should be quantified for an effective implementation of water management policies adaptive to future climate change. In this study, a modeling chain framework to project future hydrological changes and the associated uncertainties in the Xijiang River basin, South China, was established. The framework consists of three emission scenarios (ESs), four climate models (CMs), four statistical downscaling (SD) methods, four hydrological modeling (HM) schemes, and four probability distributions (PDs) for extreme flow frequency analyses. Direct variance method was adopted to analyze the manner by which uncertainty sources such as ES, CM, SD, and HM affect the estimates of future evapotranspiration (ET) and streamflow, and to quantify the uncertainties of PDs in future flood and drought risk assessment. Results show that ES is one of the least important uncertainty sources in most situations. CM, in general, is the dominant uncertainty source for the projections of monthly ET and monthly streamflow during most of the annual cycle, daily streamflow below the 99.6% quantile level, and extreme low flow. SD is the most predominant uncertainty source in the projections of extreme high flow, and has a considerable percentage of uncertainty contribution in monthly streamflow projections in July-September. The effects of SD in other cases are negligible. HM is a non-ignorable uncertainty source that has the potential to produce much larger uncertainties for the projections of low flow and ET in warm and wet seasons than for the projections of high flow. PD contributes a larger percentage of uncertainty in extreme flood projections than it does in extreme low flow estimates. Despite the large uncertainties in hydrological projections, this work found that future extreme low flow would undergo a considerable reduction, and a noticeable increase in drought risk in the Xijiang

  2. A new framework to evaluate ecosystem health: a case study in the Wei River basin, China.

    Science.gov (United States)

    Wu, Wei; Xu, Zongxue; Zhan, Chesheng; Yin, Xuwang; Yu, Songyan

    2015-07-01

    Due to the rapid growth of the population and the development of economies in the Guanzhong district, central China, the river ecosystem is gradually deteriorating, which makes it important to assess the aquatic ecosystem health and take measures to restore the damaged ecosystem. An index of catchment ecosystem health has been developed to assist large-scale management of watersheds by providing an integrated measure of ecosystem health, including aquatic and terrestrial ecosystem. Most researches focus on aquatic ecosystem or terrestrial ecosystem, but little research integrates both of them to assess the catchment ecosystem health. In this paper, we combine these two aspects into catchment ecosystem health. Ecosystem indicators derived from field samples and modeling are identified to integrate into ecosystem health. These included indicators of ecological landscape pattern (based on normalized difference vegetation index (NDVI), vegetation cover, dominance index, Shannon's diversity index, Shannon's evenness index, and fragmentation index), hydrology regime (based on 33 hydrological parameters), physical form condition (based on substrate, habitat complexity, velocity/depth regimes, bank stability, channel alteration), water quality (based on electrical conductivity (Cond), dissolved oxygen (DO), NH3_N, total nitrogen (TN), total phosphorus (TP), chemical oxygen demand-permanganate (CODMn)), and biological quality (based on fish abundance). The index of ecosystem health is applied in the Guanzhong district, and the ecosystem health was fair. The ecosystem health in the upstream to Linjiacun (U-L) and Linjiacun to Weijiabao (L-W) reaches was in good situation, while that in Weijiabao to Xianyang (W-X), Xianyang-Weijiabao (X-W), and Weijiabao to Tongguan (W-T) reaches was in fair situation. There is a trend that the ecosystem health in the upstream was better than that in the downstream. The ecosystem health assessment is expected to play a key role in future

  3. Provenance evolution of the Jurassic northern Qaidam Basin (West China) and its geological implications: evidence from detrital zircon geochronology

    Science.gov (United States)

    Yu, Long; Xiao, Ancheng; Wu, Lei; Tian, Yuntao; Rittner, Martin; Lou, Qianqian; Pan, Xiaotian

    2017-03-01

    The Jurassic system is the major hydrocarbon source rock and of crucial importance for understanding the Mesozoic intra-continental tectonics in West China. This paper presents systematic detrital zircon geochronology of the Jurassic outcropping at the Dameigou locality in the northern Qaidam Basin, and reports 1000 single-grain U-Pb zircon ages that have implications for the provenance, the corresponding basin property as well as the tectonic setting of West China during Jurassic. Zircon ages exhibit two major clusters at 250 and 2400 Ma whereas two minor clusters at 450 and 850 Ma, suggesting primary sources from the East Kunlun Shan and Oulongbuluke Block, secondary sources from the North Qaidam UHP belt and South Qilian Shan. Combined with observation of lithology and sedimentary facies, two rifting periods were inferred in the earliest Jurassic and the early stage of the Middle Jurassic, respectively, accompanied by further extension throughout the Jurassic. Our results do not support a foreland basin related to the Jurassic southward thrusting of the South Qilian Shan, but favor that the Mesozoic intra-continental tectonics in West China were characterised by pulsed responses to specific collisions rather than a persisting contractional setting during Jurassic period.

  4. Urbanization dramatically altered the water balances of a paddy field dominated basin in Southern China

    Science.gov (United States)

    Hao, L.; Sun, G.; Liu, Y.; Wan, J.; Qin, M.; Qian, H.; Liu, C.; John, R.; Fan, P.; Chen, J.

    2015-02-01

    Rice paddy fields provide important ecosystem services (e.g., food production, water retention, carbon sequestration) to a large population globally. However, these benefits are declining as a result of rapid environmental and socioeconomic transformations characterized by population growth, urbanization, and climate change in many Asian countries. This case study examined the responses of streamflow and watershed water balances to the decline of rice paddy fields due to urbanization in the Qinhuai River Basin in southern China where massive industrialization has occurred in the region during the past three decades. We found that streamflow increased by 58% and evapotranspiration (ET) decreased by 23% during 1986-2013 as a result of an increase in urban areas of three folds and reduction of rice paddy field by 27%. Both highflows and lowflows increased significantly by about 28% from 2002 to 2013. The increases in streamflow were consistent with the decreases in ET and leaf area index monitored by independent remote sensing MODIS data. The reduction in ET and increase in streamflow was attributed to the large cropland conversion that overwhelmed the effects of regional climate warming and climate variability. Converting traditional rice paddy fields to urban use dramatically altered land surface conditions from a water-dominated to a human-dominated landscape, and thus was considered as one of the extreme types of contemporary hydrologic disturbances. The ongoing large-scale urbanization in the rice paddy-dominated regions in the humid southern China, and East Asia, will likely elevate stormflow volume, aggravate flood risks, and intensify urban heat island effects. Understanding the linkage between land use change and changes in hydrological processes is essential for better management of urbanizing watersheds.

  5. Precipitation variability and response to the changing Indian summer monsoon in the Yarlung Tsangpo River basin, China

    Science.gov (United States)

    Sang, Y. F.; Singh, V. P.; Gong, T.

    2017-12-01

    This study investigated the spatiotemporal variability of precipitation over the last four decades in the Yarlung Tsangpo River (YTR) basin, China, and the impact thereon of the changing Indian summer monsoon at inter-annual and decadal temporal scales. Results reflect the spatial variability in the seasonal distribution of precipitation in the YTR basin. From downstream to upstream, the rainy season is delayed and becomes shorter, and the ratio of rainy season precipitation to annual precipitation increases, but the absolute amounts of both the rainy season precipitation and annual precipitation decrease. All the precipitation series have similar scaling characteristics, reflecting similar climatic condition in the basin. However, the effect of the Indian summer monsoon strengthens from downstream to upstream, and on this basis the YTR basin is roughly divided into three regions: east, mid and west. The decadal variations of precipitation in the three regions are similar. Overall, the annual precipitation has been exhibiting a downward trend since 1998, which is mainly caused by the decrease in the rainy season precipitation. Both the occurrence times and magnitudes of precipitation extremes have been exhibiting a downward trend over the last four decades, which bodes well for the water disaster control in the basin. The Indian summer monsoon index (ISMI), as an intensity indicator for the Indian summer monsoon, shows a positive relationship with the summer precipitation in the YTR basin. Periodic variability of the Indian summer monsoon determines the inter-annual fluctuations of precipitation in the YTR basin. Especially, the weakening effect of the Indian monsoonhas caused an obvious decrease in rainy season precipitation after 1998. If the Indian summer monsoon keeps the present weakening effect, precipitation decrease and water shortage would become more severe in the YTR basin. Effective adaptation strategies should therefore be developed proactively and

  6. Phenotypic and Molecular Genetic Characteristics ofYersinia pestisat an Emerging Natural Plague Focus, Junggar Basin, China.

    Science.gov (United States)

    Zhang, Yujiang; Luo, Tao; Yang, Chao; Yue, Xihong; Guo, Rong; Wang, Xinhui; Buren, Mingde; Song, Yuqin; Yang, Ruifu; Cao, Hanli; Cui, Yujun; Dai, Xiang

    2018-01-01

    The 15th natural plague focus in China, the Junggar Basin plague focus, is located near an important communication route connecting China and Central Asia and was discovered after 2005. To characterize the phenotypic and genetic diversity of the Yersinia pestis population in this newly established focus, we collected 25 Y. pestis strains from six counties across Junggar Basin in 2005-2006, and determined their biochemical features and genotypes based on multiple-locus variable number of tandem repeats analysis and clustered regularly interspaced short palindromic repeats analysis. We inferred the phylogenetic positions and possible sources of the Junggar strains by comparing their genotypes with the genetic diversity for known representative Y. pestis strains. Our results indicate that the major genotype of Junggar strains belongs to 2.MED1, a lineage of biovar Medievalis with identical biochemical characters and high virulence in mice. Although share a similar ecology, the 2.MED1 in Junggar Basin are not descended from known strains in the neighboring Central Asian Desert plague foci. Therefore, the emergence of the Junggar Basin plague focus is not attributable to the recent clonal spread of Y. pestis from Central Asia. We also identified two distinct minor genotypes in Junggar Basin, one of which clusters genetically with the 0.ANT1 strains of the Tianshan Mountain natural plague focus and another belongs to a 1.IN lineage not previously reported. Our study clarifies the phenotypic and genetic characters of Junggar Y. pestis strains. These findings extend our knowledge of the population diversity of Y. pestis and will facilitate future plague surveillance and prevention in Junggar Basin and adjacent regions.

  7. Prediction of hydrological responds to climate changes in the Upper Yangtze River Basin, China

    Science.gov (United States)

    Yang, X.; Ren, L.; Wang, Y.; Zhang, M.; Liu, Y.; Jiang, S.; Yuan, F.

    2017-12-01

    Climate changes have direct effects on hydrological cycle, with the increasing temperature and seasonal shift of precipitation. Therefore, understanding of how climate change may affect the population and water resources and economic development is critical to the water and food security for China. This study aims to evaluate the potential impacts of future climate changes on water resources of the upper basin of Yangtze River (the area controlled by the Yichang hydrological station) using the variable infiltration capacity (VIC) model driven by composite observations (1961-2005) and projections of eight CMIP5 models under scenarios RCP4.5 and RCP8.5 from 2006 to 2099. The raw eight CMIP5 models have been downscaled by the equidistant cumulative distribution functions (EDCDF) statistical downscaling approach from 1961 to 2099. The assessment of the performance of model simulated precipitation and temperature were calculated by comparing to the observations during the historical period (1961-2005). For the same variables, eight CMIP5 models for RCP 4.5 and RCP 8.5 downscaled by EDCDF method were generated during the future period (2006-2099). Overall, the VIC model performed well in monthly streamflow simulation, with the Nash-Sutcliffe coefficient of efficiency (NSCE) 0.92 and 0.97 for calibration and validation, respectively. The annual precipitation is projected to increase by 6.3mm and 8.6mm per decade and the annual temperature will increase by 0.22 °C and 0.53°C per decade (2006-2099) for RCP4.5 and RCP8.5, respectively. In the future period, The total runoff of the study basins would either remain stable or moderately increase by 2.7% and 22.4% per decade, the evapotranspiration increase by 2mm and 13mm per decade, and the soil moisture will reduce by -0.1% and -7.4% per decade under RCP4.5 and RCP8.5, respectively. The changes of model-simulated soil moisture, runoff, and evapotranspiration suggest that there probably be an increasing risk of drought in

  8. Effects of Ethnic Settlements and Land Management Status on Species Distribution Patterns: A Case Study of Endangered Musk Deer (Moschus spp. in Northwest Yunnan, China.

    Directory of Open Access Journals (Sweden)

    Xueyou Li

    Full Text Available Understanding the status and spatial distribution of endangered species in biologically and ethnologically diverse areas is important to address correlates of cultural and biological diversity. We developed models for endangered musk deer (Moschus spp. abundance indices in and around protected areas inhabited by different ethnic groups in northwest Yunnan China to address different anthropogenic and management-related questions. We found that prediction of relative abundance of musk deer was best accomplished using ethnicity of settlements, conservation status and poaching pressure in an area. Musk deer were around 5 times more abundant in Tibetan regions relative to Lisu regions. We found no significant negative correlates of gathering and transhumance activities on musk deer abundance. Hunting pressure showed no significant differences between protected and non-protected areas, but showed significant differences among ethnic groups. Hunting pressures in areas adjacent to Lisu settlements was 7.1 times more than in areas adjacent to Tibetan settlements. Our findings indicate protected areas in southwest China are not fully effective in deterring human disturbance caused by traditional practices. We suggest that conservation and management strategies should engage traditional culture and practices with a positive conservation impact. Better understanding of indigenous culture may open up new opportunities for species conservation in much wider tracts of unprotected and human-dominated lands. Traditional practices that are not destructive to biodiversity should be allowed as a way of providing a link between the local communities and protected areas thereby creating incentives for conservation.

  9. Effects of Ethnic Settlements and Land Management Status on Species Distribution Patterns: A Case Study of Endangered Musk Deer (Moschus spp.) in Northwest Yunnan, China.

    Science.gov (United States)

    Li, Xueyou; Bleisch, William V; Jiang, Xuelong

    2016-01-01

    Understanding the status and spatial distribution of endangered species in biologically and ethnologically diverse areas is important to address correlates of cultural and biological diversity. We developed models for endangered musk deer (Moschus spp.) abundance indices in and around protected areas inhabited by different ethnic groups in northwest Yunnan China to address different anthropogenic and management-related questions. We found that prediction of relative abundance of musk deer was best accomplished using ethnicity of settlements, conservation status and poaching pressure in an area. Musk deer were around 5 times more abundant in Tibetan regions relative to Lisu regions. We found no significant negative correlates of gathering and transhumance activities on musk deer abundance. Hunting pressure showed no significant differences between protected and non-protected areas, but showed significant differences among ethnic groups. Hunting pressures in areas adjacent to Lisu settlements was 7.1 times more than in areas adjacent to Tibetan settlements. Our findings indicate protected areas in southwest China are not fully effective in deterring human disturbance caused by traditional practices. We suggest that conservation and management strategies should engage traditional culture and practices with a positive conservation impact. Better understanding of indigenous culture may open up new opportunities for species conservation in much wider tracts of unprotected and human-dominated lands. Traditional practices that are not destructive to biodiversity should be allowed as a way of providing a link between the local communities and protected areas thereby creating incentives for conservation.

  10. Hot food and beverage consumption and the risk of esophageal squamous cell carcinoma: A case-control study in a northwest area in China.

    Science.gov (United States)

    Tai, Wei-Ping; Nie, Guo-Ji; Chen, Meng-Jie; Yaz, Tajigul Yiminni; Guli, Arzi; Wuxur, Arzigul; Huang, Qing-Qing; Lin, Zhi-Gang; Wu, Jing

    2017-12-01

    This study was trying to investigate the association of hot food and beverage consumption and the risk of esophageal squamous cell carcinoma in Hotan, a northwest area of China with high risk of esophageal squmous cell carcinoma. A population-based case-control study was designed. For the study, 167 patients diagnosed with esophageal squamous cell carcinoma were selected from Hotan during 2014 to 2015, and 167 community-based controls were selected from the same area, matched with age and sex. Information involved of temperature of food and beverage intake was obtained by face-to-face interview. Logistic regression analyses were performed to investigate the association between temperature of food and beverage intake and the risk of esophageal squamous cell carcinoma. The temperature of the food and beverage consumed by the esophageal squamous cell carcinoma patients was significantly higher than the controls. High temperature of tea, water, and food intake significantly increased the risk of esophageal squamous cell carcinoma by more than 2-fold, with adjusted odds ratio 2.23 (1.45-2.90), 2.13 (1.53-2.66), and 2.98 (1.89-4.12). Intake of food and beverage with high temperature was positively associated with the incidence of esophageal squamous cell carcinoma in Northwestern China. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  11. Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections in stray and pet cats (Felis catus) in northwest China: co-infections and risk factors.

    Science.gov (United States)

    Cong, Wei; Meng, Qing-Feng; Blaga, Radu; Villena, Isabelle; Zhu, Xing-Quan; Qian, Ai-Dong

    2016-01-01

    This study was conducted to estimate the prevalence of Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections among stray and pet cats in Lanzhou, northwest China, and to identify the influence of age, gender, and regions on seropositivity. T. gondii antibodies were examined in cat sera by the modified agglutination test (MAT). The circulating antigens of D. immitis and FeLV and specific antibodies to FIV were examined using kits commercially available. The overall prevalence of T. gondii, FIV, FeLV, and D. immitis was 19.34, 9.12, 11.33, and 3.04 %, respectively. For the genetic characterization of T. gondii genotypes in cats, genomic DNA was extracted from the seropositive cats and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genotyped using multilocus PCR-RFLP. Two T. gondii genotypes (ToxoDB#9 and ToxoDB#1) were identified. Results of the multivariate logistic regression analysis showed that older cats are more likely to be seropositive than juveniles for T. gondii, FIV, FeLV, and D. immitis. This is the first report of T. gondii genotypes in cats in northwest China. Moreover, the present study is the first study of retrovirus and D. immitis seroprevalence in cats in China. The results revealed that T. gondii, FIV, and FeLV infections are common in stray and pet cats in northwest China.

  12. Seismic fracture detection of shale gas reservoir in Longmaxi formation, Sichuan Basin, China

    Science.gov (United States)

    Lu, Yujia; Cao, Junxing; Jiang, Xudong

    2017-11-01

    In the shale reservoirs, fractures play an important role, which not only provide space for the oil and gas, but also offer favorable petroleum migration channel. Therefore, it is of great significance to study the fractures characteristics in shale reservoirs for the exploration and development of shale gas. In this paper, four analysis technologies involving coherence, curvature attribute, structural stress field simulation and pre-stack P-wave azimuthal anisotropy have been applied to predict the fractures distribution in the Longmaxi formation, Silurian, southeast of Sichuan Basin, China. By using the coherence and curvature attribute, we got the spatial distribution characteristics of fractures in the study area. Structural stress field simulation can help us obtain distribution characteristics of structural fractures. And using the azimuth P-wave fracture detection technology, we got the characteristics about the fracture orientation and density of this region. Application results show that there are NW and NE fractures in the study block, which is basically consistent with the result of log interpretation. The results also provide reliable geological basis for shale gas sweet spots prediction.

  13. Petroleum geology of the Puguang sour gas field in the Sichuan Basin, SW China

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yongsheng; Guo, Tonglou; Zhu, Guangyou; Cai, Xunyu [SINOPEC Southern Exploration and Development Company, Kunming, Yunnan 650200 (China); Zhang, Shuichang [PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083 (China); Li, Maowen [Geological Survey of (Canada)

    2008-04-15

    The Puguang sour gas field in northeastern Sichuan Basin is the largest gas discovery in the Paleozoic marine strata in China, with at least 9 trillion cubic feet (tcf) of proven gas reserves. It is one of the many anticlinal structures formed during the Indo-Sinian orogeny, with gas being trapped in a composite structure-lithology pool. The presence of the Upper Permian coal measures, Lower Silurian and Lower Cambrian marine shales provided excellent hydrocarbon source rocks. The Lower Triassic and Upper Permian oolitic dolomites serve as high quality reservoir rocks, with 10-25% porosity and 1-1000 mD permeability, largely due to diagenetically produced secondary porosity. The Lower and Middle Triassic evaporate beds have acted as the direct top seal for the large Lower Triassic-Upper Permian gas accumulation. The thick Upper Triassic and Jurassic mudstone beds regionally cap the underlying marine carbonate strata. The deep-seated basement faults acted as vertical hydrocarbon migration conduits during faulting, and became effective flow barriers when the faulting ceased. The deep burial of a paleo-oil accumulation in reservoirs rich in sulfate resulted in extensive thermochemical sulfate reduction (TSR). This, together with the new gas injection and structural reconfiguration, transformed a paleo-oil pool to a large sour gas pool. (author)

  14. Antibiotics in Crab Ponds of Lake Guchenghu Basin, China: Occurrence, Temporal Variations, and Ecological Risks

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    Wenxia Wang

    2018-03-01

    Full Text Available Antibiotics are widely used in aquaculture, however, this often results in undesirable ecological effects. To evaluate the occurrence, temporal variations, and ecological risk of antibiotics in five crab ponds of Lake Guchenghu Basin, China, 44 antibiotics from nine classes were analyzed by rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS. Twelve antibiotics belonging to six classes were detected in the aqueous phase of five crab ponds, among which sulfonamides and macrolides were the predominant classes, and six compounds (sulfamonomethoxine, sulfadiazine, trimethoprim, erythromycin-H2O, monensin, and florfenicol were frequently detected at high concentrations. In general, the antibiotic levels varied between different crab ponds, with the average concentrations ranging from 122 to 1440 ng/L. The antibiotic concentrations in crab ponds exhibited obvious seasonal variations, with the highest concentration and detection frequency detected in summer. Multivariate analysis showed that antibiotic concentrations were significantly correlated with environmental variables, such as total organic carbon, phosphate, ammonia nitrogen, and pH. Sulfadiazine, clarithromycin, erythromycin-H2O, and ciprofloxacin posed a high risk to algae, while the mixture of antibiotics could pose a high risk to aquatic organisms in the crab ponds. Overall, the usage of antibiotics in farming ponds should be comprehensively investigated and controlled to preserve a healthy aquaculture ecosystem.

  15. Estimation of potassium and magnesium flows in animal production in Dianchi Lake basin, China.

    Science.gov (United States)

    Amachika, Yuta; Anzai, Hiroki; Wang, Lin; Oishi, Kazato; Irbis, Chagan; Li, Kunzhi; Kumagai, Hajime; Inamura, Tatsuya; Hirooka, Hiroyuki

    2016-07-01

    The objectives of this study were to estimate and evaluate potassium (K) and magnesium (Mg) budgets and flows of animal production in the basin of Dianchi Lake, China. Feed sampling and farmer interviews were conducted in field surveys. The supplies of K and Mg from local and external feeds and the retention, production and excretion of animals were calculated individually for dairy cows, fattening pigs, breeding sows, and broilers and laying hens. The K and Mg flows on a regional level were estimated using the individual budgets. At the individual level, in dairy cattle, the K and Mg supplied from local feeds accounted for large parts of the total nutrient intakes, whereas in the other animal categories most of the K and Mg in the feeds depended on external resources. Our findings also suggested that excessive Mg intake resulted in high Mg excretion and low use efficiency in dairy cattle and fattening pigs. At the regional level, the K and Mg amounts of manure produced and applied in the area (K: 339 and Mg: 143 t/year) exceeded those used as local feeds. Our results imply the animal production potentially increased the K and Mg loads in the regional agriculture system. © 2015 Japanese Society of Animal Science.

  16. Ecosystem Services Value Assessment and Uneven Development of the Qingjiang River Basin in China

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    Zhengsong Lin

    2017-12-01

    Full Text Available As an important ecological barrier in Southwest China, the Qingjiang river basin plays a vital role in shaping the mountainous terrain. This paper analyzes the Ecosystem Services Value (ESV using a series of methods based on the data of changes in land use from 2000 to 2015 and the statistical yearbook. The changes in land use between 2000 and 2015 were dominated by forest land, which accounted for 60.63% of the total area, followed by arable landwhich accounted for about 22.26%, while grassland and other land use contribution rates were the lowest, accounting for only about 17.11%. Environmental changes and economic development were uneven. The regional comprehensive strength of En’shi City, Changyang County, and Yidu City were among the highest, while Badong County, Hefeng County, and Wufeng County were among the lowest in the area under study. In addition, the ESV in 2035 was estimated to be 1.56 billion dollars, a decrease of 27.64% when compared with the year 2000. The ESV of Yidu City, Lichuan City, Jianshi County, and Hefeng County grew faster, at the rates of 94.76%, 65.12%, 96.96%, and 92.38%, respectively. However, the ESV of En’shi City, Badong County, Wufeng County and Xuan’en County showed a downward trend, at the rates of −32.53%, −487.80%, −368.07%, and −181.52%, respectively.

  17. Groundwater Microbial Communities Along a Generalized Flowpath in Nomhon Area, Qaidam Basin, China.

    Science.gov (United States)

    Sheng, Yizhi; Wang, Guangcai; Zhao, Dan; Hao, Chunbo; Liu, Chenglong; Cui, Linfeng; Zhang, Ge

    2017-11-09

    Spatial distribution (horizonal and vertical) of groundwater microbial communities and the hydrogeochemistry in confined aquifers were studied approximately along the groundwater flow path from coteau to plain in the Nomhon area, Qinghai-Tibet plateau, China. The confined groundwater samples at different depths and locations were collected in three boreholes through a hydrogeological section in this arid and semi-arid area. The phylogenetic analysis of 16S rRNA genes and multivariate statistical analysis were used to elucidate similarities and differences between groundwater microbial communities and hydrogeochemical properties. The integrated isotopic geochemical measurements were applied to estimate the source and recharge characteristics of groundwater. The results showed that groundwater varied from fresh to saline water, and modern water to ancient water following the flowpath. The recharge characteristics of the saline water was distinct with that of fresh water. Cell abundance did not vary greatly along the hydrogeochemical zonality; however, dissimilarities in habitat-based microbial community structures were evident, changing from Betaproteobacteria in the apex of alluvial fan to Gammaproteobacteria and then to Epsilonproteobacteria in the core of the basin (alluvial-lacustrine plain). Rhodoferax, Hydrogenophaga, Pseudomonas, and bacterium isolated from similar habitats unevenly thrived in the spatially distinct fresh water environments, while Sulfurimonas dominanted in the saline water environment. The microbial communities presented likely reflected to the hydrogeochemical similarities and zonalities along groundwater flowpath. © 2017, National Ground Water Association.

  18. Impacts of calibration strategies and ensemble methods on ensemble flood forecasting over Lanjiang basin, Southeast China

    Science.gov (United States)

    Liu, Li; Xu, Yue-Ping

    2017-04-01

    Ensemble flood forecasting driven by numerical weather prediction products is becoming more commonly used in operational flood forecasting applications.In this study, a hydrological ensemble flood forecasting system based on Variable Infiltration Capacity (VIC) model and quantitative precipitation forecasts from TIGGE dataset is constructed for Lanjiang Basin, Southeast China. The impacts of calibration strategies and ensemble methods on the performance of the system are then evaluated.The hydrological model is optimized by parallel programmed ɛ-NSGAII multi-objective algorithm and two respectively parameterized models are determined to simulate daily flows and peak flows coupled with a modular approach.The results indicatethat the ɛ-NSGAII algorithm permits more efficient optimization and rational determination on parameter setting.It is demonstrated that the multimodel ensemble streamflow mean have better skills than the best singlemodel ensemble mean (ECMWF) and the multimodel ensembles weighted on members and skill scores outperform other multimodel ensembles. For typical flood event, it is proved that the flood can be predicted 3-4 days in advance, but the flows in rising limb can be captured with only 1-2 days ahead due to the flash feature. With respect to peak flows selected by Peaks Over Threshold approach, the ensemble means from either singlemodel or multimodels are generally underestimated as the extreme values are smoothed out by ensemble process.

  19. Architecture and quantitative assessment of channeled clastic deposits, Shihezi sandstone (Lower Permian, Ordos Basin, China

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    Chengye Jia

    2017-02-01

    Full Text Available Lower Permian Shihezi sandstone in Ordos Basin is the largest gas reservoir in China. Architecture elements of channel, overbank and floodplain facies of braided channel deposits were identified through an outcrops survey, and their proportion of channel facies have been quantitatively estimated from well logging. Characteristics of architecture elements, such as sand thickness, bounding surfaces and lithofacies were investigated through outcrops and core. Petrology of Shihezi sandstone has also been studied in detail. Analysis on sandstone components shows that monocrystalline quartz with approximately 76% bulk volume, and lithic up to 5%–45% bulk volume, are the two main components. Litharenite and lithic quartz sandstone are the main rock types. Compaction is concluded by former researchers as the control factor of low permeability. Examination through thin section reveals that secondary pores developed well in coarse sand. Inter-granular dissolution is included as the positive effect to increasing porosity, and is concluded as the control factor to the generation of net pay. Scale of coarse grained channel fills and channel bar sandstone bodies are quantitatively estimated. Strike-oriented, dip-oriented, and vertical distribution of channel fills and channel bar sandstone bodies have been investigated. The geometry of sand bodies can be depicted as an elongated lens. Subsurface mapping reveals that channel sandstone bodies distribute widely from both lateral and longitudinal cross section profiles, and are poorly connected.

  20. Regional Frequency Analysis of Extreme Dry Spells during Rainy Season in the Wei River Basin, China

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    Dunxian She

    2016-01-01

    Full Text Available Our research analyzes the regional changes of extreme dry spell, represented by the annual maximum dry spell length (noted as AMDSL during the rainy season in the Wei River Basin (WRB of China for 1960–2014 using the L-moments method. The mean AMDSL values increase from the west to the east of the WRB, suggesting a high dry risk in the east compared to the west in the WRB. To investigate the regional frequency more reasonably, the WRB is clustered into four homogenous subregions via the K-means method and some subjective adjustments. The goodness-of-fit test shows that the GEV, PE3, and GLO distribution can be accepted as the “best-fit” model for subregions 1 and 4, subregion 2, and subregion 3, respectively. The quantiles of AMDSL under various return levels figure out a similar spatial distribution with mean AMDSL. We also find that the dry risk in subregion 2 and subregion 4 might be higher than that in subregion 1. The relationship between ENSO events and extreme dry spell events in the rainy season with cross wavelet analysis method proves that ENSO events play a critical role in triggering extreme dry events during rainy season in the WRB.

  1. Floristic Characteristics and Biodiversity Patterns in the Baishuijiang River Basin, China

    Science.gov (United States)

    Liu, Bing; Zhao, Wenzhi; Wen, Zijuan; Teng, Jirong; Li, Xiaohong

    2009-07-01

    A case study was conducted on the forest ecosystem in the Baishuijiang River basin of China to reveal the influences of environmental factors and human disturbance on the floristic characteristics and biodiversity patterns. Field surveys of the floristic composition, environmental factors, and disturbance factors were conducted along an elevation gradient, and the relationships between biodiversity pattern and environmental factors were analyzed using CCA (canonical correspondence analysis). The results showed that the floristic composition of higher plants consisted of 197 families, 796 genera, 2165 species, 19 subspecies, 239 varietas, and 12 forma, and it was characterized by the multi-geographic composition and by the transition from tropical to temperate zones. Along an elevation gradient, the variations in α and β diversity were best described by a bimodal curve, and the peak values occurred at middle elevations. The CCA indicated that the elevation had the greatest influence on the biodiversity pattern, followed by the topographic index, slope direction, slope, slope position, slope shape, and vegetation coverage. In addition, human disturbance has greatly impacted the floristic composition and biodiversity patterns, and the biodiversity indices were higher with intermediate disturbance at middle elevations compared to higher and lower disturbances at low and high elevations, respectively. This reflected a disturbance-diversity pattern and thus revealed the obvious importance to maintain the intermediate disturbance for biodiversity conservation.

  2. Spatio-Temporal Variations and Source Apportionment of Water Pollution in Danjiangkou Reservoir Basin, Central China

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    Pan Chen

    2015-05-01

    Full Text Available Understanding the spatio-temporal variation and the potential source of water pollution could greatly improve our knowledge of human impacts on the environment. In this work, data of 11 water quality indices were collected during 2012–2014 at 10 monitoring sites in the mainstream and major tributaries of the Danjiangkou Reservoir Basin, Central China. The fuzzy comprehensive assessment (FCA, the cluster analysis (CA and the discriminant analysis (DA were used to assess the water pollution status and analyze its spatio-temporal variation. Ten sites were classified by the high pollution (HP region and the low pollution (LP region, while 12 months were divided into the wet season and the dry season. It was found that the HP region was mainly in the small tributaries with small drainage areas and low average annual discharges, and it was also found that most of these rivers went through urban areas with industrial and domestic sewages input into the water body. Principal component analysis/factor analysis (PCA/FA was applied to reveal potential pollution sources, whereas absolute principal component score-multiple linear regression (APCS-MLR was used to identify their contributions to each water quality variable. The study area was found as being generally affected by industrial and domestic sewage. Furthermore, the HP region was polluted by chemical industries, and the LP region was influenced by agricultural and livestock sewage.

  3. The Upper Jurassic-Lower Cretaceous of eastern Heilongjiang, Northeast China: stratigraphy and regional basin history

    Energy Technology Data Exchange (ETDEWEB)

    Sha, J.G.; Matsukawa, M.; Cai, H.W.; Jiang, B.Y.; Ito, M.; He, C.Q.; Gu, Z.W. [Academy of Sinica, Nanjing (China)

    2003-12-01

    In eastern Heilongjiang, the Upper Jurassic is marine and restricted to the Suibin and Dong'an areas, where it is characterized faunally by Callovian-Volgian (Tithonian) bivalves and florally by dinoflagellates. The Lower Cretaceous is widely distributed in eastern Heilongjiang, and characterized faunally by Berriasian-Valanginian bivalves, Barremian-Albian ammonites and Aucellina, and florally by dinoflagellates. To the west, the marine facies grade into non-marine beds. Thus, in the east, for example in the Dong'an and Dajiashan areas, near the northwestern Palaeo-Pacific, the Lower Cretaceous is marine; westward, in the Yunshan, Longzhaogou. Peide, and Zhushan areas, marine and non-marine deposits alternate, whereas further west still, e.g. in the Jixi Basin, non-marine facies are intercalated with marine beds. This regional distribution is indicative of a large, shallow embayment opening eastwards to the Palaeo-Pacific; during the Early Cretaceous successive transgressive-regressive events influenced the climate and biota of eastern Heilongjiang and northeastern China. Many of the Lower Cretaceous sections contain abundant coals, demonstrating that in this region the Early Cretaceous was an important coal-forming period.

  4. Simulation of hydrological processes in the Zhalong wetland within a river basin, Northeast China

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    X. Q. Feng

    2013-07-01

    Full Text Available Zhalong National Nature Preserve is a large wetland reserve on the Songnen Plain in Northeast China. Wetlands in the preserve play a key role in maintaining regional ecosystem function and integrity. Global climate change and intensified anthropogenic activities in the region have raised great concerns over the change of natural flow regime, wetland degradation and loss. In this study, two key hydrologic components in the preserve, water surface area and water volume, as well as their variations during the period 1985–2006, were investigated with a spatially-distributed hydrologic modeling system (SWAT. A wetland module was incorporated into the SWAT model to represent hydrological linkages between the wetland and adjacent upland areas. The modified modeling system was calibrated with streamflow measurements from 1987 to 1989 and was validated for the period 2005–2006. The calibration achieved a Nash efficiency coefficient (Ens of 0.86, and the validation yielded an Ens of 0.66. In the past 20 yr, water surface area in the Zhalong wetland fluctuated from approximately 200 km2 to 1145 km2 with a rapid decreasing trend through the early 2000s. Consequently, water volume decreased largely in the preserve, especially in the dry seasons. The situation changed following the implementation of a river diversion in 2001. Overall, the modeling yielded plausible estimates of hydrologic changes in this large wetland reserve, building a foundation for assessing ecological water requirements and developing strategies and plans for future water resources management within the river basin.

  5. Geothermal constraints on Emeishan mantle plume magmatism: paleotemperature reconstruction of the Sichuan Basin, SW China

    Science.gov (United States)

    Zhu, Chuanqing; Hu, Shengbiao; Qiu, Nansheng; Jiang, Qiang; Rao, Song; Liu, Shuai

    2018-01-01

    The Middle-Late Permian Emeishan Large Igneous Province (ELIP) in southwestern China represents a classic example of a mantle plume origin. To constrain the thermal regime of the ELIP and contemporaneous magmatic activity in the northeastern Sichuan Basin, maximum paleotemperature profiles of deep boreholes were reconstructed using vitrinite reflectance (Ro) and apatite fission track data. Two heating patterns were identified: (1) heating of the overlying lithosphere by magma storage regions and/or magmatic activity related to the mantle plume, which resulted in a relatively strong geothermal field and (2) direct heating of country rock by stock or basalt. Borehole Ro data and reconstructed maximum paleotemperature profiles near the ELIP exhibit abrupt tectonothermal unconformities between the Middle and Late Permian. The profiles in the lower subsections (i.e., pre-Middle Permian) exhibited significantly higher gradients than those in the upper subsections. Distal to the basalt province, high paleo-geotemperatures (hereafter, paleotemperatures) were inferred, despite deformation of the paleogeothermal curve due to deep faults and igneous rocks within the boreholes. In contrast, Ro profiles from boreholes without igneous rocks (i.e., Late Permian) contained no break at the unconformity. Paleotemperature gradients of the upper and the lower subsections and erosion at the Middle/Late Permian unconformity revealed variations in the thermal regime. The inferred spatial distribution of the paleothermal regime and the erosion magnitudes record the magmatic and tectonic-thermal response to the Emeishan mantle plume.

  6. Organic geochemistry of oil and gas in the Kuqa depression, Tarim Basin, NW China

    Energy Technology Data Exchange (ETDEWEB)

    Digang Liang; Shuichang Zhang; Jianping Chen [China National Petroleum Corporation, Beijing (China). Key Laboratory for Petroleum Geochemistry; Research Institute of Petroleum Exploration and Development, PetroChina, Beijing (China); Feiyu Wang [China National Petroleum Corporation, Beijing (China). Key Laboratory for Petroleum Geochemistry; Peirong Wang [China National Petroleum Corporation, Beijing (China). Key Laboratory for Petroleum Geochemistry; Jianghan Petroleum Institute (China)

    2003-07-01

    The Kuqa depression in the Tarim Basin, NW China contains significant natural gas and condensate resources, with only small amounts of black oil. This study demonstrates that the primary reason for the accumulation of large natural gas reserves in the Kuqa depression is the high maturity level of the Jurassic coal-bearing sequence that is currently at the peak stage of dry gas generation. From the combined stable carbon isotopes and molecular and biomarker data it is possible to identify two separate source rocks for the discovered hydrocarbon fluids: the gases were primarily from the Middle-Lower Jurassic coals and associated clastic rocks, and the oils were from the Upper Triassic lacustrine mudstones. Peak oil generation from the Triassic source rocks occurred during the early Miocene (23-12 Ma b.p.). These oils migrated laterally over relatively long distances ({approx}20-50 km) reaching the outer periphery of the depression. Peak gas generation took place more recently, perhaps during the past 5 Ma. The gases migrated mainly along faults over relatively short lateral distances, resulting in accumulations adjacent to the over-matured source kitchens. Different timings for the trap formation along the north and south margins and a late injection of gas into early oil accumulations provided favorable conditions for the formation of evaporative condensates and the preservation of gas pools in the more down-dip reservoirs and oil pools in the more up-dip locations. (author)

  7. Multivariate Regression Analysis and Statistical Modeling for Summer Extreme Precipitation over the Yangtze River Basin, China

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    Tao Gao

    2014-01-01

    Full Text Available Extreme precipitation is likely to be one of the most severe meteorological disasters in China; however, studies on the physical factors affecting precipitation extremes and corresponding prediction models are not accurately available. From a new point of view, the sensible heat flux (SHF and latent heat flux (LHF, which have significant impacts on summer extreme rainfall in Yangtze River basin (YRB, have been quantified and then selections of the impact factors are conducted. Firstly, a regional extreme precipitation index was applied to determine Regions of Significant Correlation (RSC by analyzing spatial distribution of correlation coefficients between this index and SHF, LHF, and sea surface temperature (SST on global ocean scale; then the time series of SHF, LHF, and SST in RSCs during 1967–2010 were selected. Furthermore, other factors that significantly affect variations in precipitation extremes over YRB were also selected. The methods of multiple stepwise regression and leave-one-out cross-validation (LOOCV were utilized to analyze and test influencing factors and statistical prediction model. The correlation coefficient between observed regional extreme index and model simulation result is 0.85, with significant level at 99%. This suggested that the forecast skill was acceptable although many aspects of the prediction model should be improved.

  8. 26Al/10Be burial dating of Xujiayao-Houjiayao site in Nihewan Basin, northern China.

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    Hua Tu

    Full Text Available The Xujiayao-Houjiayao site in Nihewan Basin is among the most important Paleolithic sites in China for having provided a rich collection of hominin and mammalian fossils and lithic artifacts. Based on biostratigraphical correlation and exploratory results from a variety of dating methods, the site has been widely accepted as early Upper Pleistocene in time. However, more recent paleomagnetic analyses assigned a much older age of ∼500 ka (thousand years. This paper reports the application of 26Al/10Be burial dating as an independent check. Two quartz samples from a lower cultural horizon give a weighted mean age of 0.24 ± 0.05 Ma (million years, 1σ. The site is thus younger than 340 ka at 95% confidence, which is at variance with the previous paleomagnetic results. On the other hand, our result suggests an age of older than 140 ka for the site's lower cultural deposits, which is consistent with recent post-infrared infrared stimulated luminescence (pIR-IRSL dating at 160-220 ka.

  9. Pollution from animal husbandry in China: a case study of the Han River Basin.

    Science.gov (United States)

    Sun, Chen; Wu, Hongjuan

    2012-01-01

    Animal husbandry is one of the major agricultural pollution sources in China. The Xiangyang Reach of the Han River Basin was used as a case study to identify pollutants from animal rearing. The gross amount of pollutants from livestock and poultry rearing in the Xiangyang Reach was estimated using two empirical models with different data sets. The pig, cattle, sheep, and poultry population in 2009 amounted to 2.6, 0.6, 0.5, and 39.2 million head, respectively. The total annual pollutant loads generated from the feces and urine of livestock and poultry were 270,400 t of chemical oxygen demand; 228,900 t of biochemical oxygen demand; 26,500 t of ammonia nitrogen; 16,500 t of total phosphorus; and 63,900 t of total nitrogen. Approximately 12% of these pollutant loads were estimated to enter the Han River through the watershed outlet. Animal breeding has been one of the main pollution sources in this area, followed by domestic sewage and industrial wastewater. Cattle produced the most pollution, with the heaviest pollution load in downtown Xiangyang City. Several recommendations are presented to control the pollution caused by livestock and poultry breeding.

  10. The inter-decadal correlation between summer arctic oscillation and summer drought and moist characteristic of northwest China

    Science.gov (United States)

    Wang, Pengxiang; Zheng, Youfei; Sun, Landong; Ren, Zhenhe; He, Jinhai; Zhang, Qiang

    2007-09-01

    In the context of 1960~2003 summertime rainfall and small-sized pan evaporations from 131 stations distributed over NW China covering Xinjiang, Qinghai, Gansu, Ningxia, Shaanxi as well as western Nei Mongolia, and Arctic Oscillation Indices (AOI) we define a homogenized index for aridity or wetness feature, with which to examine the relations between AOI and NW China aridity-wetness regime, indicating their noticeable relations on an interdecadal basis. It is found that during the decade of summer Arctic oscillation stronger than mean, the sea level pressure field shows positive (negative) anomalies over Asian landmass, a stronger anticyclonic anomaly circulation appears at 700 hPa over Lake Baikal and to the south, westerly (northerly) departure emerges in the westerly (monsoon) portion of NW China, as well as over NW China there appears a structure with a low in the west and a high in the east at the 500 hPa height field, suggestive of east-Asian summer monsoon weaker than normal such that westerly flows prevail in the westerly zone of NW China, leading to rainfall more than mean for a wetter climate while in its monsoon area the northerly winds are dominant, with precipitation less than normal, resulting in a climate drier in comparison to mean and v.v. for the decade with summer AO weaker than normal.

  11. Effects of biochemical and physical processes on concentrations and size distributions of dimethylaminium and trimethylaminium in atmospheric particles from marginal seas of China to the northwest Pacific Ocean

    Science.gov (United States)

    Hu, Q.; Yao, X.; Qu, K.; Cui, Z.; Gao, H.; Xie, H.

    2017-12-01

    This study aim to assess the effects of concentrations and size distributions of aminium ions in atmospheric particles from offshore to open oceans. Size-segregated dimethylaminium (DMA+) and trimethylaminium (TMA+) in atmospheric particles were measured during March-May, 2014. One cruise was over marginal seas of China, in which the concentrations of DMA+ and TMA+ in PM0.056-10 varied from 0.08 nmol m-3 to 0.43 nmol m-3 and from 0.10 to 0.27 nmol m-3, respectively. The two ions both had good positive correlations with subsurface chlorophyll-a maximum and salinity, respectively. The highest concentrations of (DMA+ + TMA+) were observed during cyanobacteria bloom period which happened in subsurface water. The results implied that the concentrations of DMA+ (TMA+) in marine atmospheric particles might be influenced by phytoplankton quantities and species in subsurface seawater. Another cruise was carried out from marginal seas of China to the northwest Pacific Ocean (NWPO). The concentrations of DMA+ and TMA+ in PM0.056-1.8 varied from 0.19 nmol m-3 to 1.53 nmol m-3 and from 0.57 to 3.85 nmol m-3, respectively. The highest (lowest) concentrations of (DMA+ + TMA+) were observed near the cyclonic (anticyclonic) eddy, indicating that the cyclonic (anticyclonic) eddy with high (low) chlorophyll-a enhanced (suppressed) DMA+ (TMA+) production in atmospheric particles. In addition, the dominant particle modes less than 0.2 μm for DMA+ (TMA+) were observed, ie., 0.13±0.02 μm for DMA+ over marginal seas of China, and 0.08±0.00 μm for TMA+ in NWPO, but if they were emitted via bubble bursting needed to be further researched.

  12. Correction of two Upper Paleozoic stratigraphic units in the Tianshan Mountains region, Xinjiang Uygur Autonomous Region and implications on the Late Paleozoic evolution of Tianshan tectonic complex, Northwest China

    Directory of Open Access Journals (Sweden)

    Zhong-Qiang Chen

    2015-10-01

    Full Text Available The present paper addresses two tectonostratigraphic concerns on the Late Paleozoic Tianshan tectonic complex (TTC, Xinjiang, Northwest (NW China: (1 stratigraphic succession and age constraint of the Bayingou ophiolite mélange, eastern Tianshan Mountains and (2 timing of closure of the southern Tianshan ocean and accretion of the Siberian craton recorded in the Aiweiergou (AWEG area, eastern Tianshan Mountains by integrating stratigraphy, palaeontology, tectonopalaeogeography and palaeobiogeography. In the Bayingou area, the detailed palaeontological survey denies the presence of brachiopod Gigantoproductus fauna, typical of the Early Carboniferous faunas in central–south Tianshan complex, in the Anjihai Formation. In contrast, the Anjihai brachiopod assemblage, as a whole, appears to have a high affinity with the Late Devonian faunas of the eastern Junggar Basin, northern Xinjiang, suggesting a Late Devonian age for the Anjihai Formation. The overlying Shadawang Formation yields the Early Carboniferous radiolarians. These two units form the main part of the Bayingou ophiolite mélange, which therefore is likely Late Devonian to Early Carboniferous in age. The Bayingou area has been likely part of the northern Tianshan-Junggar block since the Late Devonian, although it may have been part of the Central Tianshan tectonostratigraphic province prior to the Late Devonian. The topmost strata of the Bayingou ophiolite mélange are characterized by alternation of volcanics, conglomerate and mudstone, and are better re-assigned to the Taoxigou Group rather than the Keguqingshan Formation. The Bayingou ophiolite mélange comprises the Late Devonian Anjihai Formation, the Carboniferous Bayingou and Shadawang Formations, and the Early Permian Taoxigou Group. In the AWEG area, the Permian and Triassic rocks were previously misinterpreted as the Late Permian turbidites and Late Triassic red beds, respectively. In fact, the Permian successions in AWEG

  13. Origin of back-arc basins and effects of western Pacific subduction systems on eastern China geology

    Science.gov (United States)

    Niu, Y.

    2013-12-01

    Assuming that subduction initiation is a consequence of lateral compositional buoyancy contrast within the lithosphere [1], and recognizing that subduction initiation within normal oceanic lithosphere is unlikely [1], we can assert that passive continental margins that are locations of the largest compositional buoyancy contrast within the lithosphere are the loci of future subduction zones [1]. We hypothesize that western Pacific back-arc basins were developed as and evolved from rifting at passive continental margins in response to initiation and continuation of subduction zones. This hypothesis can be tested by demonstrating that intra-oceanic island arcs must have basement of continental origin. The geology of the Islands of Japan supports this. The highly depleted forearc peridotites (sub-continental lithosphere material) from Tonga and Mariana offer independent lines of evidence for the hypothesis [1]. The origin and evolution of the Okinawa Trough (back-arc basin) and Ryukyu Arc/Trench systems represents the modern example of subduction initiation and back-arc basin formation along a (Chinese) continental margin. The observation why back-arc basins exit behind some subduction zones (e.g., western Pacific) but not others (e.g., in South America) depends on how the overlying plate responds to subduction, slab-rollback and trench retreat. In the western Pacific, trench retreat towards east results in the development of extension in the upper Eurasian plate and formation of back-arc basins. In the case of South America, where no back-arc basins form because trench retreat related extension is focused at the 'weakest' South Mid-Atlantic Ridge. It is thus conceptually correct that the South Atlantic is equivalent to a huge 'back-arc basin' although its origin may be different. Given the negative Clayperon slope of the Perovskite-ringwoodite phase transition at the 660 km mantle seismic discontinuity (660-D), slab penetration across the 660-D is difficult and

  14. Examining the effects of urban agglomeration polders on flood events in Qinhuai River basin, China with HEC-HMS model.

    Science.gov (United States)

    Gao, Yuqin; Yuan, Yu; Wang, Huaizhi; Schmidt, Arthur R; Wang, Kexuan; Ye, Liu

    2017-05-01

    The urban agglomeration polders type of flood control pattern is a general flood control pattern in the eastern plain area and some of the secondary river basins in China. A HEC-HMS model of Qinhuai River basin based on the flood control pattern was established for simulating basin runoff, examining the impact of urban agglomeration polders on flood events, and estimating the effects of urbanization on hydrological processes of the urban agglomeration polders in Qinhuai River basin. The results indicate that the urban agglomeration polders could increase the peak flow and flood volume. The smaller the scale of the flood, the more significant the influence of the polder was to the flood volume. The distribution of the city circle polder has no obvious impact on the flood volume, but has effect on the peak flow. The closer the polder is to basin output, the smaller the influence it has on peak flows. As the level of urbanization gradually improving of city circle polder, flood volumes and peak flows gradually increase compared to those with the current level of urbanization (the impervious rate was 20%). The potential change in flood volume and peak flow with increasing impervious rate shows a linear relationship.

  15. Palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin, northern South China Sea.

    Science.gov (United States)

    Li, Wenhao; Zhang, Zhihuan; Wang, Weiming; Lu, Shuangfang; Li, Youchuan; Fu, Ning

    2014-01-01

    The main factors of the developmental environment of marine source rocks in continental margin basins have their specificality. This realization, in return, has led to the recognition that the developmental environment and pattern of marine source rocks, especially for the source rocks in continental margin basins, are still controversial or poorly understood. Through the analysis of the trace elements and maceral data, the developmental environment of Miocene marine source rocks in the Qiongdongnan Basin is reconstructed, and the developmental patterns of the Miocene marine source rocks are established. This paper attempts to reveal the hydrocarbon potential of the Miocene marine source rocks in different environment and speculate the quality of source rocks in bathyal region of the continental slope without exploratory well. Our results highlight the palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin of the northern South China Sea and speculate the hydrocarbon potential of the source rocks in the bathyal region. This study provides a window for better understanding the main factors influencing the marine source rocks in the continental margin basins, including productivity, preservation conditions, and the input of terrestrial organic matter.

  16. Optimal Water Resources Allocation under the Constraint of Land Use in the Heihe River Basin of China

    Directory of Open Access Journals (Sweden)

    Zhanqi Wang

    2015-02-01

    Full Text Available In recent years, water scarcity and irrational utilization have become the pivotal issues for the sustainable development of river basins in China. This paper attempts to propose a new perspective for the optimization of water resources allocation in a typical river basin. In order to conduct an accurate and feasible program for water resources allocation in the water-deficient river basin, a multi-objective and multi-constraint programming model was developed by embedding land use effect as a constraint on water allocation, which was currently solely decided by water resources demand in different water use sectors. The program includes two layers, namely water allocation among different counties located in the middle reaches of the Heihe River Basin and among domestic, industrial, agricultural and ecological uses within one county. Empirical analysis shows that the structural change of land use has an important influence and restriction on the water resources allocation in the river basin. The least cultivated areas that ensure food security and the constraint of construction land quota have great impact on agricultural and industrial water allocation. Moreover, the quantitative change of ecological land greatly affects ecological water allocation. The results demonstrate that the optimal program calculated from land use embedded model can well predicate the actual situation of water allocation in the future. To ensure regional sustainable development, it is vital that reasonable water-saving measures in each water use sector and ecological protection policies be taken.

  17. A new net primary production estimating model using NOAA-AVHRR applied to the Haihe Basin, China

    Science.gov (United States)

    Xu, Xingang; Wu, Bingfang; Li, Qiangzi; Meng, Jihua; Zhang, Fengli

    2006-10-01

    Terrestrial net primary production (NPP), as an important component of carbon cycle on land, not only indicates directly the production level of vegetation community on land, but also shows the status of terrestrial ecosystem. What's more, NPP is also a determinant of carbon sinks on land and a key regulator of ecological processes, including interactions among tropic levels. In the study, three existing models are combined with each other to assess net primary production in Haihe Basin, China. The photosynthetically active radiation (PAR) model of Monteith is used for the calculation of absorbed photosynthetically active radiation (APAR), the light utilization efficiency model of Potter et al. is used for determining the light utilization efficiency, and the surface energy balance system (SEBS) of Su is used into Potter's model to describe water stress in land wetness conditions. To assess NPP, We use NOAA-AVHRR data from November 2003 to September 2004 and the corresponding daily data of temperature and hours of sunshine obtained from meteorological stations in Haihe Basin, China. After atmospheric, geometrical and radiant corrections, every ten days NOAA data are processed to become an image of NDVI by means of the maximal value composition method (MVC) in order to eliminate some noises. Using these data, we compute NPP in spring season and spring season of 2004 in Haihe Basin, China. The result shows, in Haihe Basin, NPP for spring season is averaged to 336.10gC•m -2, and 709.16 gC•m -2 for autumn season. In spatial distribution, NPP is greater in both ends than in middle for spring season, and decrease increasingly from north to south for autumn season. Future work should rely on the integration of high and low resolution images to assess net primary production, which will probably have more accurately estimation.

  18. Drowning unconformity of lacustrine rift basins: A case study from the Dongying Sag in Bohai Bay Basin, China

    Science.gov (United States)

    Chen, R.; Fan, J.

    2015-12-01

    The concept of drowning unconformity of lacustrine rift basins was proposed in this paper. This paper utilized 3D seismic data, well-log and the principles methods associated with structural geology, sedimentology and geochemistry, to analyze the drowning unconformity and discuss the origins of drowning unconformity in Dongying Sag in Bohai Bay Basin.Researching on it is not only important for a better understanding of tectonic evolution, palaeogeography and sedimentation of hydrocarbon source rocks, but also a vital guiding significance for the exploration of beach-bar sandstone reservoirs and shale oil.1. The concept of drowning unconformity of lacustrine rift basins is defined. With the consequences of rapid tectonic subsidence in basin, the sharp rise of lake-level and the increased rate of accommodation(A) in basin exceeded the rate of sediment supply(S),namely A>>S, the basin suddenly transformed into deep-water settings from shallow-water settings with sudden change of sediment transport and sediment dispersal patterns. 2.The sequence surface between Sha4 and Sha3 Member of Shahejie Formation is the drowning unconformity(43.5Ma). There are the sedimentary association of the reefs in shallow lacustrine, beach-bar sandstones and glutenite fan bodies under the surface. By contrast, there are the sedimentary association of deep-lake oil shales and shales over the surface. The drowning unconformity in Dongying Sag is a tectonic revolution surface which is changed from extensional tectonics to transtensional tectonics and it is also the surface of discontinuity from shallow lacustrine to deep lacustrine. The responses to sudden changes appeared in the parameters of geophysics, geochemistry and paleontology. 3. With the penetration of India into Asia plate in NNE trending,the subduction zones of Pacific Plate retreated. It caused the rapid downwelling of asthenospheric mantle, followed by the extensive drowning unconformity.

  19. Projection of future runoff change using climate elasticity method derived from Budyko framework in major basins across China

    Science.gov (United States)

    Xing, Wanqiu; Wang, Weiguang; Zou, Shan; Deng, Chao

    2018-03-01

    This study established a climate elasticity method based on Budyko hypothesis and enhanced it by selecting the most effective Budyko-type formula to strengthen the runoff change prediction reliability. The spatiotemporal variations in hydrologic variables (i.e., runoff, precipitation and potential evaporation) during historical period were revealed first and the climate elasticities of runoff were investigated. The proposed climate elasticity method was also applied to project the spatiotemporal variations in future runoff and its key influencing factors in 35 watersheds across China. Wherein, the future climate series were retrieved by consulting the historical series, informed by four global climate models (GCMs) under representative concentration pathways from phase five of the Coupled Model Intercomparison Project. Wang-Tang equation was selected as the optimal Budyko-type equation for its best ability in reproducing the runoff change (with a coefficient of determination and mean absolute error of 0.998 and 1.36 mm, respectively). Observed runoff presents significant decreasing trends in the northern and increasing trends in the southern regions of China, and generally its change is identified to be more sensitive to climatic variables in Hai River Basin and lower Yellow River Basin. Compared to the runoff during the reference period, positive change rates in the north and negative change rates in the south of China in the mid-21st century can be practically generalized from the majority of GCMs projections. This maybe resulted from the increasing precipitation, especially in parts of northern basins. Meanwhile, GCMs project a consistently upward trend in potential evaporation although significant decreasing trends occur in the majority of catchments for the historical period. The results indicate that climate change will possibly bring some changes to the water resources over China in the mid-21st century and some countermeasures of water resources planning

  20. The role of scenario analysis in water resources management in Yanqi Basin, Xinjiang, China

    Science.gov (United States)

    Li, N.; Kinzelbach, W. K.; Li, W.; Dong, X.

    2011-12-01

    With the rapid increase of world population and food demand, the demand for water resources is also increasing. At the same time shifts in rain patterns due to global climate change make the water resources situation more uncertain. A global water crisis can therefore not be excluded. The socio-economic and environmental problems induced by such a water crisis are especially prominent in arid and semiarid regions. The Yanqi Basin in Xinjiang province is a typical case study in China's arid and semi-arid areas, where rainfall is scarce and evaporation is extremely high. Thus its water resources have been under great pressure to satisfy the increasing water demand of agriculture and urban and industrial expansion in the last decades. The development has been accompanied by a number of environmental problems. Yanqi Basin is an important cultivated area which is irrigated by water diverted from rivers. Because of the long-term flood irrigation and an inefficient drainage system, the groundwater level under the cultivated area rose, accelerating the phreatic evaporation and leading to increased soil salinization. Simultaneously, the water quantity and quality of Boston Lake have been impaired in past years because of the decreased river discharge and the increased salt flux contained in the drainage discharge. Thus the ecosystems depending on the inflow to and outflow from the lake suffered. The riverine forests in the downstream area were degraded due to declining groundwater levels, and aquatic life as well as downstream water users had to cope with deteriorating water quality. The big challenge for decision makers in the basin is how to balance the justified requirements of agriculture, industrial development and the ecosystem. In order to provide a scientific basis to the decision making process, a scenario analysis was adopted. Here several scenarios are proposed: the basic scenario, scenario 1, describes the status of the year 2008. A second scenario maximizes the

  1. Prevalence of BRCA1 and BRCA2 Germline Mutations in Breast Cancer Women of Multiple Ethnic Region in Northwest China

    NARCIS (Netherlands)

    Ou, Jianghua; Wu, Tao; Sijmons, Rolf; Ni, Duo; Xu, Wenting; Upur, Halmurat

    Purpose: The aim of this study is to further understand the status of BRCA1 and BRCA2 mutation among Chinese high-risk breast cancer patients in multiple-ethnic regions of China. Methods: A total of 79 blood samples of high-risk breast cancer patients from Xinjiang Uyghur autonomous region were

  2. Lacustrine basin evolution and coal accumulation of the Middle Jurassic in the Saishiteng coalfield, northern Qaidam Basin, China

    Directory of Open Access Journals (Sweden)

    Meng Li

    2016-07-01

    Full Text Available Based on an extensive borehole survey of the Middle Jurassic coal-bearing sequences in the Saishiteng coalfield, northern Qaidam Basin (NQB, a total of 20 rock types and 5 sedimentary facies were identified, including braided river, meandering river, braided delta, meandering river delta, and lacustrine facies. The distribution of rock types and sedimentary facies contributed to the reconstruction of three periods' sedimentary facies maps of the Middle Jurassic in the Saishiteng coalfield, namely, the Dameigou age, the early Shimengou age and the late Shimengou age. That also provided the basis for the development of a three-stage depositional model of the Middle Jurassic in the NQB, indicating the lacustrine basin of the NQB in the Dameigou age and early Shimengou age were corresponding to an overfill basin, and that in the late Shimengou age was related to a balanced-fill basin. The analysis of the stability and structure of coal seams based on sedimentary facies maps showed that the preferred coal-forming facies in the Saishiteng coalfield were inter-delta bay and interdistributary bay of lower delta plain in the Dameigou age. In particular, the swamps that developed on the subaqueous palaeohigh favored the development of thick coal seams. Thus, minable coal seams may also be found along the Pingtai palaeohigh in the western part of the Saishiteng coalfield.

  3. [Effects of plastic film mulching with double ridges and furrow planting on soil moisture and temperature and soybean yield on a semiarid dryland of Gansu Province, Northwest China].

    Science.gov (United States)

    Yang, Feng-Ke; Wang, Li-Ming; Zhang, Guo-Hong

    2013-11-01

    Taking soybean cultivar Jindou 23 as test object, a field experiment was conducted at the Zhenyuan experimental station of Gansu Academy of Agricultural Sciences to study the effects of various plastic mulching treatments on the soil moisture and temperature and soybean grain yield on a semiarid dryland of Northwest China. Four treatments were installed, i. e., plastic film mulching with double ridges and furrow planting (FMRFC), plastic film mulching without ridges and with furrow planting (FMFC), plastic film mulching with strip planting (FMSC), and no mulch strip planting (NMSC, CK). During the drought year (the precipitation in soybean growth period was 246.3 mm) and wet year (407 mm), the daily soil temperature in 0-20 cm layer in all mulching treatments varied in "S" shape, and its fluctuation became smaller with soybean growth. The mulching treatments raised the daily average soil temperature in 0-20 cm layer by an average of 0.5-2.5 degrees C from the seedling (VE-V3) to seed filling (R6) stage, with the average soil temperature in whole growth period raised by 1.3-1.6 degrees C. Both in dry year and in wet year, mulching treatments promoted the soil moisture consumption in 0-120 cm layer, by soybean, but increased the average soil moisture content and water storage in 0-200 cm layer by 1.2%-1.4% and 62.7-70.3 mm, respectively. As compared to CK, treatments FMRFC and FMFC had significant effects in improving the soil temperature and moisture environment in dry year, and greatly improved the yield-related traits such as plant height, branching number, pods per plant, and 100-seed mass. FMRFC increased the yield by 27.7%-51.1% and raised the water use efficiency (WUE) by 47.7%- 56.3%, whereas FMFC increased the yield by 10.2% -25.2% and raised the WUE by 33.3%-35.4%, as compared to CK. It was suggested that FMRFC and FMFC could be the most efficient planting systems for the soybean production in the dryland farming of Northwest China.

  4. Intra-Annual Variation of Stem Radius of Larix principis-rupprechtii and Its Response to Environmental Factors in Liupan Mountains of Northwest China

    Directory of Open Access Journals (Sweden)

    Zebin Liu

    2017-10-01

    Full Text Available Fine-resolution studies on the stem radius variation at short timescale can provide useful information about the tree growth process and the major environmental variables that trigger and drive stem radius variation. This study investigated the stem radius variation of Larix principis-rupprechtii Mayr growing in the semi-humid Liupan Mountains of Northwest China at daily and seasonal scales using high-resolution automatic band dendrometers from May to October in 2015. The results showed that the stem radius variation of Larix principis-rupprechtii has a clear diurnal pattern which can be divided into contraction, recovery, and increment phases; and also a seasonal pattern which can be divided into three stages: (1 the rapid growth stage in spring (stage 1 with the radius increment of 94.0% of the total in the entire growing period; (2 the persistent shrinkage stage in the dry summer (stage 2 with a negative diurnal radius increment for most days, and a significantly larger amplitude of stem contraction and recovery than other stages; (3 the minimal growth stage in autumn (stage 3, mainly caused by the lowering temperature and leaf area. The amplitude of stem contraction was significantly correlated with air temperature (both the mean and highest value in all three stages: vapor pressure deficit (VPD in stage 1; relative humidity (RH, VPD and soil moisture (Ms in stage 2; and soil temperature (Ts in stage 3. This indicates that the stem radius contraction was mainly controlled by the factors influencing tree transpiration rate in spring and autumn stages, but jointly controlled by the factors influencing both the tree transpiration rate and the soil moisture availability in the dry summer stage. The factors controlling the stem radius recovery was similar to the stem contraction. The amplitude of stem increment was significantly correlated with the rainfall amount and air temperature (both the mean and highest value in stage 1 and 3, Ms in stage

  5. Urbanization dramatically altered the water balances of a paddy field-dominated basin in southern China

    Science.gov (United States)

    Hao, L.; Sun, G.; Liu, Y.; Wan, J.; Qin, M.; Qian, H.; Liu, C.; Zheng, J.; John, R.; Fan, P.; Chen, J.

    2015-07-01

    Rice paddy fields provide important ecosystem services (e.g., food production, water retention, carbon sequestration) to a large population globally. However, these benefits are diminishing as a result of rapid environmental and socioeconomic transformations, characterized by population growth, urbanization, and climate change in many Asian countries. This case study examined the responses of stream flow and watershed water balances to the decline of rice paddy fields due to urbanization in the Qinhuai River basin in southern China, where massive industrialization has occurred during the past 3 decades. We found that stream flow increased by 58 % and evapotranspiration (ET) decreased by 23 % during 1986-2013 as a result of a three-fold increase in urban areas and a reduction of rice paddy fields by 27 %. Both high flows and low flows increased significantly by about 28 % from 2002 to 2013. The increases in stream flow were consistent with the decreases in ET and leaf area index monitored by independent remote sensing MODIS (Moderate Resolution Imaging Spectroradiometer) data. Attribution analysis, based on two empirical models, indicated that land-use/land-cover change contributed about 82-108 % of the observed increase in stream flow from 353 ± 287 mm yr-1 during 1986-2002 to 556 ± 145 during 2003-2013. We concluded that the reduction in ET was largely attributed to the conversion of cropland to urban use. The effects of land-use change overwhelmed the effects of regional climate warming and climate variability. Converting traditional rice paddy fields to urban use dramatically altered land surface conditions from an artificial wetland-dominated landscape to an urban land-use- dominated one, and thus was considered an extreme type of contemporary hydrologic disturbance. The ongoing large-scale urbanization of the rice paddy-dominated regions, in humid southern China and East Asia, will likely elevate storm-flow volume, aggravate flood risks, and intensify urban

  6. Epidermal characters of Tamarix L. (Tamaricaceae) from Northwest China and their taxonomic and palaeogeographic implications

    OpenAIRE

    Jian-Wei Zhang; Ashalata D'Rozario; Shi-Min Duan; Xi-Yong Wang; Xiao-Qing Liang; Bo-Rong Pan

    2018-01-01

    The taxonomical position of species of the genus Tamarix (Tamaricaceae) has been criticized because of their gross morphological similarities (such as slender, smooth and reddish–brown branches, grey–green foliage and scale leaves), and their systematic relationships remain unclear. In this paper, the leaf epidermal features of 17 species from China are studied based on the micro-morphological characters of the epidermal cells, stomata, salt glands, papillae and epidermal hairs. According to ...

  7. Sustainable management of river oases along the Tarim River (SuMaRiO) in Northwest China under conditions of climate change

    Science.gov (United States)

    Rumbaur, C.; Thevs, N.; Disse, M.; Ahlheim, M.; Brieden, A.; Cyffka, B.; Duethmann, D.; Feike, T.; Frör, O.; Gärtner, P.; Halik, Ü.; Hill, J.; Hinnenthal, M.; Keilholz, P.; Kleinschmit, B.; Krysanova, V.; Kuba, M.; Mader, S.; Menz, C.; Othmanli, H.; Pelz, S.; Schroeder, M.; Siew, T. F.; Stender, V.; Stahr, K.; Thomas, F. M.; Welp, M.; Wortmann, M.; Zhao, X.; Chen, X.; Jiang, T.; Luo, J.; Yimit, H.; Yu, R.; Zhang, X.; Zhao, C.

    2015-03-01

    The Tarim River basin, located in Xinjiang, NW China, is the largest endorheic river basin in China and one of the largest in all of Central Asia. Due to the extremely arid climate, with an annual precipitation of less than 100 mm, the water supply along the Aksu and Tarim rivers solely depends on river water. This is linked to anthropogenic activities (e.g., agriculture) and natural and semi-natural ecosystems as both compete for water. The ongoing increase in water consumption by agriculture and other human activities in this region has been enhancing the competition for water between human needs and nature. Against this background, 11 German and 6 Chinese universities and research institutes have formed the consortium SuMaRiO (Sustainable Management of River Oases along the Tarim River; blank">http://www.sumario.de), which aims to create a holistic picture of the availability of water resources in the Tarim River basin and the impacts on anthropogenic activities and natural ecosystems caused by the water distribution within the Tarim River basin. On the basis of the results from field studies and modeling approaches as well as from suggestions by the relevant regional stakeholders, a decision support tool (DST) will be implemented that will then assist stakeholders in balancing the competition for water, acknowledging the major external effects of water allocation to agriculture and to natural ecosystems. This consortium was formed in 2011 and is funded by the German Federal Ministry of Education and Research. As the data collection phase was finished this year, the paper presented here brings together the results from the fields from the disciplines of climate modeling, cryology, hydrology, agricultural sciences, ecology, geoinformatics, and social sciences in order to present a comprehensive picture of the effects of different water availability schemes on anthropogenic activities and natural ecosystems along the Tarim River. The second objective is to present

  8. Hydrochemical Characteristics and Formation of the Saline or Salty Springs in Eastern Sichuan Basin of China

    Science.gov (United States)

    Zhou, X.

    2017-12-01

    Saline or salty springs provide important information on the hydrogeochemical processes and hydrology within subsurface aquifers. More than 20 saline and salty springs occur in the core of anticlines in the eastern Sichuan Basin in southwestern China where the Lower and Middle Triassic carbonates outcrop. Water samples of 8 saline and salty springs (including one saline hot spring) were collected for analyses of the major and minor constituents, trace elements and stable oxygen and hydrogen isotopes. The TDS of the springs range from 4 to 83 g/L, and they are mainly of Cl-Na type. Sr, Ba and Li are the predominant trace elements. The δ2H and δ18O of the water samples indicate that they are of meteoric origin. The source of salinity of the springs originates from dissolution of minerals in the carbonates, including halite, gypsum, calcite and dolomite. The formation mechanism of the springs is that groundwater receives recharge from infiltration of precipitation, undergoes shallow or deep circulation in the core of the anticline and incongruent dissolution of the salt-bearing carbonates occurs, and emerges in the river valley in the form of springs with relatively high TDS. The 8 springs can be classified into 4 springs of shallow groundwater circulation and 4 springs of deep groundwater circulation according to the depth of groundwater circulation, 7 springs of normal temperature and 1 hot spring according to temperature. There are also 2 up-flow springs: the carbonate aquifers are overlain by relatively impervious sandstone and shale, groundwater may flows up to the ground surface through the local portion of the overlying aquiclude where fractures were relatively well developed, and emerges as an up-flow spring. Knowledge of the hydrochemical characteristics and the geneses of the saline and salty springs are of important significance for the utilization and preservation of the springs.

  9. Experiments of CO2 Solubility in the Synthetic Brine from the Erdos Basin, China

    Science.gov (United States)

    Wang, L.; Yu, Q.

    2015-12-01

    Solubility trapping of CO2 in saline aquifers is accepted to be the promising method in terms of carbon capture and storage (CCS). CO2 solubility at geological sequestration conditions is of great significance in evaluating the carbon capture potential of brine formation. Unfortunately, most CO2 solubility studies focus mainly on single-salt solutions, and only sparse literature exist for the data of CO2 solubility in aqueous solutions containing the mixture of K+, Na+, Ca2+ and Mg2+. To fill the research gap, an experimental investigation on the CO2 solubility in the synthetic brine is carried out. The samples were extracted through the injection wells of the Shenhua Carbon Capture and Storage project in the Erdos Basin located in northern China. The proportion of K+, Na+, Ca2+ and Mg2+ was determined by chemical analysis of the samples in the aquifers. The synthetic brine is used in this study, and the experimental process were improved to lower the risk of penetration of the supercritical fluid. Solubility data were measured over the temperature and pressure ranges of 318-348 K and 8-11 MPa. In the range studied, the average absolute deviation of CO2 solubility between literature and experimental results was 2.7%, and the maximum absolute deviation was less than 5.4%. Krichevsky-Kasarnovsky (KK) equation was established to analyze the experimental data and the effect of different ions on CO2 solubility was quantified using an optimization process. The liner fit between the CO2 solubility and mixed ion concentration is satisfied with correlation coefficient of 0.91. The proposed model and experimental data therefore possess broad adaptability to geological carbon storage. This ambiguity in the mechanism of the ion effect drives our efforts toward a better understanding of the factors controlling CO2 solubility in formation brine.

  10. Cracking and thermal maturity of Ordovician oils from Tahe Oilfield, Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Anlai Ma

    2017-12-01

    Full Text Available The thermal maturity of the Ordovician oils from the Tahe oilfield of Tarim Basin, NW China was assessed through various maturity parameters, such as biomarkers, aromatic parameters, and diamondoid parameters. Both Ts/(Ts+Tm and C29Ts/(C29H+C29Ts values indicate that the maturity of oils has not reached the condensates stage, which is consistent with the maturity obtained by MPI1. However, the diamondoid maturity suggests that the oil maturity ranges 1.1%–1.6% Ro, which is apparently higher than that of the maturity obtained by the biomarker and MPI1. This discrepancy in maturity may indicate that the Ordovician reservoir has multiple filling history. The 4-MD+3-MD concentration of oils disperses and increases slowly when the Ts/(Ts+Tm value is lower than 0.55. Meanwhile, the value increases rapidly when the Ts/(Ts+Tm value is higher than 0.55. It is proposed that the diamondoid baseline is about 15 μg/goil for marine oils in the Tahe oilfield based on the diamondoid concentration of marine oils from reservoirs of various age. The concentration of 4-MD+3-MD of most Ordovician oils generally ranges from 4.5 to 35 μg/goil, suggesting that the degree of oil-cracking is lower than 50% and the deep Ordovician have potential of oil exploration. The distribution of the concentration of 4-MD+3-MD is characterized by being high in the east and south, low in the west and north, proposing that the two migration pathways exit in the oilfield, which are from east to west and from south to north, respectively. The migration directions are consistent with the results obtained from the oil density and the maturity parameters such as Ts/(Ts+Tm. Thus, suggesting the concentration of 4-MD+3-MD can be used as migration index in oilfield scale.

  11. Hydrological and pollution processes in mining area of Fenhe River Basin in China.

    Science.gov (United States)

    Yang, Yonggang; Meng, Zhilong; Jiao, Wentao

    2018-03-01

    The hydrological and pollution processes are an important science problem for aquatic ecosystem. In this study, the samples of river water, reservoir water, shallow groundwater, deep groundwater, and precipitation in mining area are collected and analyzed. δD and δ 18 O are used to identify hydrological process. δ 15 N-NO 3 - and δ 18 O-NO 3 - are used to identify the sources and pollution process of NO 3 - . The results show that the various water bodies in Fenhe River Basin are slightly alkaline water. The ions in the water mainly come from rock weathering. The concentration of SO 4 2- is high due to the impact of coal mining activity. Deep groundwater is significantly less affected by evaporation and human activity, which is recharged by archaic groundwater. There are recharge and discharge between reservoir water, river water, soil water, and shallow groundwater. NO 3 - is the main N species in the study area, and forty-six percent of NO 3 - -N concentrations exceed the drinking water standard of China (NO 3 - -N ≤ 10 mg/L content). Nitrification is the main forming process of NO 3 - . Denitrification is also found in river water of some river branches. The sources of NO 3 - are mainly controlled by land use type along the riverbank. NO 3 - of river water in the upper reaches are come from nitrogen in precipitation and soil organic N. River water in the lower reaches is polluted by a mixture of soil organic N and fertilizers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Evolution of the Lian River coastal basin in response to Quaternary marine transgressions in Southeast China

    Science.gov (United States)

    Tang, Yongjie; Zheng, Zhuo; Chen, Cong; Wang, Mengyuan; Chen, Bishan

    2018-04-01

    The coastal basin deposit in the Lian River plain is among the thickest Quaternary sequences along the southeastern coast of China. The clastic sediment accumulated in a variety of environmental settings including fluvial, channel, estuary/coastal and marine conditions. Detailed investigation of lithofacies, grain-size distributions, magnetic susceptibility, microfossils and chronology of marine core CN01, compared with regional cores, and combined with offshore seismic reflection profiles, has allowed us to correlate the spatial stratigraphy in the inner and outer plain and the seismic units. Grain size distribution analysis of core CN-01 through compositional data analysis and multivariate statistics were applied to clastic sedimentary facies and sedimentary cycles. Results show that these methods are able to derive a robust proxy information for the depositional environment of the Lian River plain. We have also been able to reconstruct deltaic evolution in response to marine transgressions. On the basis of dating results and chronostratigraphy, the estimated age of the onset of deposition in the Lian River coastal plain was more than 260 kyr BP. Three transgressive sedimentary cycles revealed in many regional cores support this age model. Detailed lithological and microfossil studies confirm that three marine (M3, M2 and M1) and three terrestrial (T3, T2 and T1) units can be distinguished. Spatial correlation between the inner plain, outer plain (typical cores characterized by marine transgression cycles) and offshore seismic reflectors reveals coherent sedimentary sequences. Two major boundaries (unconformity and erosion surfaces) can be recognized in the seismic profiles, and these correspond to weathered reddish and/or variegated clay in the study core, suggesting that Quaternary sediment changes on the Lian River plain were largely controlled by sea-level variations and coastline shift during glacial/interglacial cycles.

  13. Socio-hydrologic Perspectives of the Co-evolution of Humans and Water in the Tarim River Basin, Western China

    Science.gov (United States)

    Liu, Ye; Tian, Fuqiang; Hu, Heping; Liu, Dengfeng; Sivapalan, Murugesu

    2013-04-01

    Socio-hydrology studies the co-evolution of coupled human-water systems, which is of great importance for long-term sustainable water resource management in basins suffering from serious eco-environmental degradation. Process socio-hydrology can benefit from the exploring the patterns of historical co-evolution of coupled human-water systems as a way to discovering the organizing principles that may underpin their co-evolution. As a self-organized entity, the human-water system in a river basin would evolve into certain steady states over a sufficiently long time but then could also experience sudden shifts due to internal or external disturbances that exceed system thresholds. In this study, we discuss three steady states (also called stages in the social sciences, including natural, human exploitation and recovery stages) and transitions between these during the past 1500 years in the Tarim River Basin of Western China, which a rich history of civilization including its place in the famous Silk Road that connected China to Europe. Specifically, during the natural stage with a sound environment that existed before the 19th century, shifts in the ecohydrological regime were mainly caused by environmental changes such river channel migration and climate change. During the human exploitation stages in the 5th and again in the 19th-20th centuries, however, humans gradually became the main drivers for system evolution, during which the basin experienced rapid population growth, fast socio-economic development and intense human activities. By the 1970s, after 200 years of colonization, the Tarim River Basin evolved into a new regime with vulnerable ecosystem and water system, and suffered from serious water shortages and desertification. Human society then began to take a critical look into the effects of their activities and reappraise the impact of human development on the ecohydrological system, which eventually led the basin into a treatment and recovery stage

  14. Successive monitoring surveys of selected banned and restricted pesticide residues in vegetables from the northwest region of China from 2011 to 2013.

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    Yu, Yan; Hu, Senke; Yang, Yuxuan; Zhao, Xiaodan; Xue, Jianjun; Zhang, Jinghua; Gao, Song; Yang, Aimin

    2017-08-02

    A wide range of pesticides is applied for crop protection in vegetable cultivation in China. Regulation of pesticide maximum residue limits (MRLs) in vegetables is established but not fully enforced. And pesticide residues in vegetables were not well monitored. This study conducted the monitoring surveys from 2011 to 2013 to investigate the pesticides in vegetables in the northwest region of China. A multi-residue gas chromatography/mass spectrometry method (GC/MS) was used in determination of pesticides in vegetable samples. The χ 2 test was used to compare the concentration of pesticide residues. A total of 32 pesticide residues were detected in 518 samples from 20 types of vegetables in this study. 7.7% of the detected pesticide residues exceeded the MRLs. The percentages of residues that exceeded the MRLs for leafy, melon and fruit, and root vegetables were 11.2%, 5.1%, and 1.6%, respectively. There was no seasonal difference in the proportion of samples that exceeded the MRLs in different vegetables. A total of 84.3% (27/32) pesticides were detected at concentrations that exceeded MRLs. And of the 27 pesticides that exceeded the MRLs, 11 (40.7%) were banned for use in agriculture. The most frequently detected pesticides were Malathion (9.4%), Dichlorvos (8.7%), and Dimethoate (8.1%). The observed high rate of pesticides detected and high incidence of pesticide detection exceeding their MRLs in the commonly consumed vegetables indicated that the Good Agricultural Practices (GAP) may not be well followed. The management of pesticide use and control should be improved. Well-developed training programs should be initiated to improve pesticide application knowledge for farmers.

  15. Successive monitoring surveys of selected banned and restricted pesticide residues in vegetables from the northwest region of China from 2011 to 2013

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    Yan Yu

    2017-08-01

    Full Text Available Abstract Background A wide range of pesticides is applied for crop protection in vegetable cultivation in China. Regulation of pesticide maximum residue limits (MRLs in vegetables is established but not fully enforced. And pesticide residues in vegetables were not well monitored. This study conducted the monitoring surveys from 2011 to 2013 to investigate the pesticides in vegetables in the northwest region of China. Methods A multi-residue gas chromatography/mass spectrometry method (GC/MS was used in determination of pesticides in vegetable samples. The χ2 test was used to compare the concentration of pesticide residues. Results A total of 32 pesticide residues were detected in 518 samples from 20 types of vegetables in this study. 7.7% of the detected pesticide residues exceeded the MRLs. The percentages of residues that exceeded the MRLs for leafy, melon and fruit, and root vegetables were 11.2%, 5.1%, and 1.6%, respectively. There was no seasonal difference in the proportion of samples that exceeded the MRLs in different vegetables. A total of 84.3% (27/32 pesticides were detected at concentrations that exceeded MRLs. And of the 27 pesticides that exceeded the MRLs, 11 (40.7% were banned for use in agriculture. The most frequently detected pesticides were Malathion (9.4%, Dichlorvos (8.7%, and Dimethoate (8.1%. Conclusion The observed high rate of pesticides detected and high incidence of pesticide detection exceeding their MRLs in the commonly consumed vegetables indicated that the Good Agricultural Practices (GAP may not be well followed. The management of pesticide use and control should be improved. Well-developed training programs should be initiated to improve pesticide application knowledge for farmers.

  16. The Wasteland Auction Policy in Northwest China: Solving Environmental Degradation and Rural Poverty? / Rural Development in Transitional China: A Special Issue

    NARCIS (Netherlands)

    Ho, P.P.S.

    2003-01-01

    In order to relieve rural poverty and solve the problem of soil and water erosion on marginal land, various provinces and regions throughout China proclaimed a new policy in the late 1980s and early 1990s. This 'Four Wastelands Auction Policy' attempts to boost the development of land of low

  17. Analysis of ancient human mitochondrial DNA from the Xiaohe cemetery: insights into prehistoric population movements in the Tarim Basin, China.

    Science.gov (United States)

    Li, Chunxiang; Ning, Chao; Hagelberg, Erika; Li, Hongjie; Zhao, Yongbin; Li, Wenying; Abuduresule, Idelisi; Zhu, Hong; Zhou, Hui

    2015-07-08

    The Tarim Basin in western China, known for its amazingly well-preserved mummies, has been for thousands of years an important crossroad between the eastern and western parts of Eurasia. Despite its key position in communications and migration, and highly diverse peoples, languages and cultures, its prehistory is poorly understood. To shed light on the origin of the populations of the Tarim Basin, we analysed mitochondrial DNA polymorphisms in human skeletal remains excavated from the Xiaohe cemetery, used by the local community between 4000 and 3500 years before present, and possibly representing some of the earliest settlers. Xiaohe people carried a wide variety of maternal lineages, including West Eurasian lineages H, K, U5, U7, U2e, T, R*, East Eurasian lineages B, C4, C5, D, G2a and Indian lineage M5. Our results indicate that the people of the Tarim Basin had a diverse maternal ancestry, with origins in Europe, central/eastern Siberia and southern/western Asia. These findings, together with information on the cultural context of the Xiaohe cemetery, can be used to test contrasting hypotheses of route of settlement into the Tarim Basin.

  18. Identification of Water Scarcity and Providing Solutions for Adapting to Climate Changes in the Heihe River Basin of China

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    Xiangzheng Deng

    2015-01-01

    Full Text Available In ecologically fragile areas with arid climate, such as the Heihe River Basin in northwestern China, sustainable social and economic development depends largely on the availability and sustainable uses of water resource. However, there is more and more serious water resource shortage and decrease of water productivity in Heihe River Basin under the influence of climate change and human activities. This paper attempts to identify the severe water scarcity under climate change and presents possible solutions for sustainable development in Heihe River Basin. Three problems that intervened land use changes, water resource, the relevant policies and institutions in Heihe River basin were identified, including (1 water scarcity along with serious contradiction between water supply and demand, (2 irrational water consumption structure along with low efficiency, and (3 deficient systems and institutions of water resource management along with unreasonable water allocation scheme. In this sense, we focused on reviewing the state of knowledge, institutions, and successful practices to cope with water scarcity at a regional extent. Possible solutions for dealing with water scarcity are explored and presented from three perspectives: (1 scientific researches needed by scientists, (2 management and institution formulation needed by governments, and (3 water resource optimal allocation by the manager at all administrative levels.

  19. A new genus of aplodontid rodent (Mammalia, Rodentia from the late Oligocene of northern Junggar Basin, China.

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    Shundong Bi

    Full Text Available A new genus and species of aplodontid rodent, Proansomys dureensis, from the late Oligocene of the northern Junggar Basin of China is described. The new genus is referred to as Ansomyinae because the ectoloph on the upper cheek teeth, although not fully crested, has attained the same characteristic bucket-handle-shaped configuration as other members of the subfamily. It represents the earliest record of the subfamily yet discovered in Asia and is more plesiomorphic than species of the genus Ansomys in having a partly crested ectoloph, a lower degree of lophodonty, and less complex tooth basins (lacking accessory lophules. Proansomys has transitional features between Prosciurus and Ansomys, suggesting that the Ansomyinae derived from a group of aplodontids related to Prosciurus, as did other advanced aplodontid rodents. This provides new light on the paleobiogeography of the Ansomyinae.

  20. Water Efficient Alternative Crops for Sustainable Agriculture along the Tarim Basin: A Comparison of the Economic Potentials of Apocynum pictum, Chinese Red Date and Cotton in Xinjiang, China

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    Aihemaitijiang Rouzi

    2017-12-01

    Full Text Available This study explores a paradigm of sustainable land use in the oases along the Tarim River of northwest China, where a fragile, semi-arid riparian ecosystem is being damaged by excessive land and water use for agriculture, especially for the growing of cotton. The reliance of agriculture on water-demanding cash crops in this region poses a grave threat to survival of the natural Tugai vegetation in the area and to the long-term sustainability of the region. We explored the hypothesis that the species Apocynum pictum (A. pictum, known as Lop-Kendir by locals, and the Chinese red date (Zyzyphus jujube may act as sustainable crop substitutes for the region, thereby replacing the widely distributed cash crop of cotton that has high water demands. Therefore, we investigated current utilization and cost-revenue structure of these two alternative plants and compared the results to cotton. Three natural resource management types of A. pictum were both identified in the wild and cultivation, with cost-revenue analysis carried out for each. The results show that all three types of institutional arrangements of natural resources, which are namely open access, ranching and farming, were present in our study and at various levels for A. pictum. A. pictum farming costs 16,250.25 yuan/ha, generates 49,014.45 yuan/ha of revenue from raw materials and brings a profit of 32,764.2 yuan/ha, which is the highest of all three cash crops compared. The Chinese government encourages Chinese red date plantations with a “Grain for green” campaign in the Tarim Basin with this plant being more profitable than cotton, which could serve to diversify the region’s agriculture. We conclude that A. pictum offers opportunities for the restoration of vegetation in riparian ecosystems on salinized sites under the arid conditions of the Tarim Basin. Furthermore, it can serve as a viable land-use alternative to cotton for cash crop agriculture, as it may generate a certain income

  1. Exploring Northwest China's agricultural water-saving strategy: analysis of water use efficiency based on an SE-DEA model conducted in Xi'an, Shaanxi Province.

    Science.gov (United States)

    Mu, L; Fang, L; Wang, H; Chen, L; Yang, Y; Qu, X J; Wang, C Y; Yuan, Y; Wang, S B; Wang, Y N

    Worldwide, water scarcity threatens delivery of water to urban centers. Increasing water use efficiency (WUE) is often recommended to reduce water demand, especially in water-scarce areas. In this paper, agricultural water use efficiency (AWUE) is examined using the super-efficient data envelopment analysis (DEA) approach in Xi'an in Northwest China at a temporal and spatial level. The grey systems analysis technique was then adopted to identify the factors that influenced the efficiency differentials under the shortage of water resources. From the perspective of temporal scales, the AWUE increased year by year during 2004-2012, and the highest (2.05) was obtained in 2009. Additionally, the AWUE was the best in the urban area at the spatial scale. Moreover, the key influencing factors of the AWUE are the financial situations and agricultural water-saving technology. Finally, we identified several knowledge gaps and proposed water-saving strategies for increasing AWUE and reducing its water demand by: (1) improving irrigation practices (timing and amounts) based on compatible water-saving techniques; (2) maximizing regional WUE by managing water resources and allocation at regional scales as well as enhancing coordination among Chinese water governance institutes.

  2. A New Insight into Shale-Gas Accumulation Conditions and Favorable Areas of the Xinkailing Formation in the Wuning Area, North-West Jiangxi, China

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    Shangru Li

    2017-12-01

    Full Text Available In north-west Jiangxi, China, most shale-gas exploration has been focused on the Lower Cambrian Hetang and Guanyintang formations, whereas the Upper Ordovician Xinkailing formation shale has been ignored for years due to heavy weathering. This study systematically analyzed gas source conditions, reservoir conditions and gas-bearing ability in order to reveal the shale-gas accumulation conditions of the Xinkailing formation. The results show that the Xinkailing formation is characterized by thick deposition of black shale (10–80 m, high organic content (with total organic carbon between 1.18% and 3.11%, on average greater than 2%, relatively moderate thermal evolution (with vitrinite reflectance between 2.83% and 3.21%, high brittle-mineral content (greater than 40%, abundant nanopores and micro-fractures, very good adsorption ability (adsorption content between 2.12 m3/t and 3.47 m3/t, on average about 2.50 m3/t, and strong sealing ability in the underlying and overlying layers, all of which favor the generation and accumulation of shale gas. The Wuning-Lixi and Jinkou-Zhelin areas of the Xinkailing formation were selected as the most realistic and favorable targets for shale-gas exploration and exploitation. In conclusion, the Wuning area has great potential and can provide a breakthrough in shale gas with further investigation.

  3. Quantitatively Verifying the Results' Rationality for Farmland Quality Evaluation with Crop Yield, a Case Study in the Northwest Henan Province, China

    Science.gov (United States)

    Huang, Junchang; Wang, Song

    2016-01-01

    Evaluating the assessing results’ rationality for farmland quality (FQ) is usually qualitative and based on farmers and experts’ perceptions of soil quality and crop yield. Its quantitative checking still remains difficult and is likely ignored. In this paper, FQ in Xiuwu County, the Northwest Henan Province, China was evaluated by the gray relational analysis (GRA) method and the traditional analytic hierarchy process (AHP) method. The consistency rate of two results was analysed. Research focused on proposing one method of testing the evaluation results’ ration