WorldWideScience

Sample records for basin northwest china

  1. Effects of climate change on water resources in Tarim River Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    CHEN Ya-ning; LI Wei-hong; XU Chang-chun; HAO Xin-ming

    2007-01-01

    Based on hydrology, temperature, and precipitation data from the past 50 years, the effects of climate change on water resources in Tarim River Basin in northwest China were investigated. The long-term trends of the hydrological time series were detected using both parametric and nonparametric techniques. The results showed that the increasing tendency of the temperature has a 5% level of significance, and the temperature increased by nearly 1℃ over the past fifty years. The precipitation showed a significant increase in the 1980s and 1990s, and the average annual precipitation exhibited an increasing trend with a magnitude of 6.8 mm per decade. A step change occurred in both the temperature and precipitation time series around 1986. The streamflow from the headwater of the Tarim River exhibited a significant increase during the last 20 years. The increase in temperature, precipitation, and streamflow may be attributed to global change.

  2. A distributed runoff model for inland mountainous river basin of Northwest China

    Institute of Scientific and Technical Information of China (English)

    CHENRensheng; KANGErsi; YANGJianping; ZHANGJishi

    2003-01-01

    In order to predict the futuristic runoff under global warming, and to approach to the effects of vegetation on the ecological environment of the inland river mountainous watershed of Northwest China, the authors use the routine hydrometric data to create a distributed monthly model with some conceptual parameters, coupled with GIS and RS tools and data. The model takes sub-basin as the minimal confluent unit, divides the main soils of the basin into 3 layers, and identifies the vegetation types as forest and pasture. The data used in the model are precipitation, air temperature, runoff, soil weight water content, soil depth, soil bulk density, soil porosity, land cover,etc. The model holds that if the water amount is greater than the water content capacity, there will be surface runoff. The actual evaporation is proportional to the product of the potential evaporation and soil volume water content. The studied basin is Heihe mainstream mountainous basin, with a drainage area of 10,009 km2. The data used in this simulation are from Jan. 1980 to Dec. 1995, and the first 10 years' data are used to simulate, while the last 5 years' data are used to calibrate. For the simulation process, the Nash-Sutcliffe Equation, Balance Error and Explained Variance is 0.8681,5.4008 and 0.8718 respectively, while for the calibration process, 0.8799, -0.5974 and 0.8800 respectively. The model results show that the futuristic runoff of Heihe river basin will increase a little. The snowmelt, glacier meltwater and the evaportranspiration will increase. The air temperature increment will make the permanent snow and glacier area diminish, and the snowline will rise. The vegetation, especially the forest in Heihe mountainous watershed, could lead to the evapoWanspimtion decrease of the watershed, adjust the runoff orocess, and increase the soil water content.

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

    Directory of Open Access Journals (Sweden)

    Z. Zeng

    2012-05-01

    Full Text Available 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 study is to quantify WF within the Heihe River Basin (HRB, a basin located in the arid and semi-arid northwest of China. The findings show that the WF was 1768 million m3 yr−1 in the HRB over 2004–2006. Agricultural production was the largest water consumer, accounting for 96% of the WF (92% for crop production and 4% for livestock production. The remaining 4% was for the industrial and domestic sectors. The "blue" component of WF was 811 million m3 yr−1. This indicates a blue water proportion of 46%, which is much higher than the world average and China's average, which is mainly due to the aridness of the HRB and a high dependence on irrigation for crop production. However, even in such a river basin, blue WF was still smaller than green WF, indicating the importance of green water. We find that blue WF exceeded blue water availability during eight months per year and also on an annual basis. This indicates that WF of human activities was achieved at a cost of violating environmental flows of natural freshwater ecosystems, and such a WF pattern is not sustainable. Considering the large WF of crop production, optimizing the crop planting pattern is often a key to achieving more sustainable water use in arid and semi-arid regions.

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

    Directory of Open Access Journals (Sweden)

    Z. Zeng

    2012-08-01

    Full Text Available 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 study is to quantify WF within the Heihe River Basin (HRB, a basin located in the arid and semi-arid northwest of China. The findings show that the WF was 1768 million m3 yr−1 in the HRB over 2004–2006. Agricultural production was the largest water consumer, accounting for 96% of the WF (92% for crop production and 4% for livestock production. The remaining 4% was for the industrial and domestic sectors. The "blue" (surface- and groundwater component of WF was 811 million m3 yr−1. This indicates a blue water proportion of 46%, which is much higher than the world average and China's average, which is mainly due to the aridness of the HRB and a high dependence on irrigation for crop production. However, even in such a river basin, blue WF was still smaller than "green" (soil water WF, indicating the importance of green water. We find that blue WF exceeded blue water availability during eight months per year and also on an annual basis. This indicates that WF of human activities was achieved at a cost of violating environmental flows of natural freshwater ecosystems, and such a WF pattern is not sustainable. Considering the large WF of crop production, optimizing the crop planting pattern is often a key to achieving more sustainable water use in arid and semi-arid regions.

  5. Hydrological Characteristics of the Heihe River Basin in the Arid Inland Area of Northwest China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The hydrological characteristics of the Heihe River Basin in the arid inland area of northwest China were investigated.The spatial distribution of annual precipitation in the basin indicates that it decreases from east to west and from south to north,and increases with elevation by a gradient of 24.4 mm per hundred meters below 2,810 m a.s.l.,but decreases with elevation by that of 37.0 mm per hundred meters above 2,810 m a.s.l.For the last 50 years,the mountain runoff of the ba-sin has a tendency of increase.Except in the mountain area,the aridity is very high in the basin,and the aridity index ranges from 1.6 to 7.0 at the piedmont,to 9.0~20.0 in the midstream area and up to 40.0 in the downstream Ejin region.It is estimated for the last 50 years that a 1oC increment of annual temperature causes a 21.5 mm increase of evaporation in the mountain area,and the equivalent reduction of mountain runoff is 0.215×109 m3/yr at the Yingluoxia Hydrometric Sta-tion.The estimation shows also that a 1oC increment of annual temperature causes 1,842 mm increase of farmland evapotranspiration in the midstream area,an equivalent of 0.298×109 m3/yr more water consumption.The anthropogenic influence on the hydrological processes and water resources is then discussed.

  6. Groundwater evolution and recharge determination of the Quaternary aquifer in the Shule River basin, Northwest China

    Science.gov (United States)

    He, Jianhua; Ma, Jinzhu; Zhao, Wei; Sun, Shuang

    2015-12-01

    Groundwater recharge and evolution in the Shule River basin, Northwest China, was investigated by a combination of hydrogeochemical tracers, stable isotopes, and radiocarbon methods. Results showed the general chemistry of the groundwater is of SO4 2- type. Water-rock reactions of halite, Glauber's salt, gypsum and celestite, and reverse ionic exchange dictated the groundwater chemistry evolution, increasing concentrations of Cl-, Na+, SO4 2-, Ca2+, Mg2+ and Sr2+ in the groundwater. The δ18O and δ2H values of groundwater ranged from -10.8 to -7.7 and -74.4 to -53.1 ‰, respectively. Modern groundwater was identified in the proluvial fan and the shallow aquifer of the fine soil plain, likely as a result of direct infiltration of rivers and irrigation returns. Deep groundwater was depleted in heavy isotopes with 14C ages ranging from 3,000 to 26,000 years, suggesting palaeowater that was recharged during the late Pleistocene and middle Holocene epochs under a cold climate. These results have important implications for groundwater management in the Shule River basin, since large amounts of groundwater are effectively being mined and a water-use strategy is urgently needed.

  7. Carbon and Nitrogen Contents in Typical Plants and Soil Profiles in Yanqi Basin of Northwest China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Juan; WANG Xiu-jun; WANG Jia-ping; WANG Wei-xia

    2014-01-01

    Carbon and nitrogen are the most important elements in the terrestrial ecosystem. Studying carbon and nitrogen distributions in plant and soil is important for our understanding of the ecosystem dynamics and carbon cycle on arid lands. A study was conducted in a typical arid area, the Yanqi Basin, Northwest China. Carbon and nitrogen distributions in plant tissues and soil proifles were determined at 21 sites with typical native plants and crops. Our results indicated that carbon content was similar between crops and native plants, and the average carbon contents in aboveground (42.4%) and belowground (42.8%) tissues were almost the same. Average nitrogen contents in crops were nearly the same (~0.7%) in aboveground and belowground tissues whereas mean nitrogen content was approximately 100% higher in aboveground (2.2%) than in belowground (1.2%) tissues for native species. Soil organic carbon (SOC) and total nitrogen (TN) in cropland (9.4 and 0.9 g kg-1) were signiifcantly higher than those in native land (6.2 and 0.7 g kg-1). Multiple regression analyses indicated that carbon content in belowground tissue and nitrogen content in aboveground tissue were key factors connecting plant and soil in native land. However, there was no signiifcant relationship for carbon or nitrogen between soil and crop, which might relfect human disturbance, such as plowing and applications of various organic materials.

  8. Baseflow simulation of SWAT model in an inland river basin in Tianshan Mountains, Northwest China

    Directory of Open Access Journals (Sweden)

    Y. Luo

    2011-11-01

    Full Text Available Baseflow is an important component in hydrological modeling. Complex streamflow recession process complicates the baseflow simulation. In order to simulate the snow and/or glacier melt dominated streamflow receding quickly during 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 applied to the Manas River basin in 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, respectively. The filter-based method estimated the baseflow index as 0.60, while the model-based as o.45. The filter-based baseflow responds almost immediately to surface runoff occurrence at onset of rising limb, while the model-based 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Baseflow simulation of SWAT model in an inland river basin in Tianshan Mountains, Northwest China

    OpenAIRE

    Luo, Y.; Arnold, J; Allen, P; Chen, X.

    2011-01-01

    Baseflow is an important component in hydrological modeling. Complex streamflow recession process complicates the baseflow simulation. In order to simulate the snow and/or glacier melt dominated streamflow receding quickly during 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 applied to the M...

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

    OpenAIRE

    Luo, Y.; Arnold, J; Allen, P; Chen, X.

    2012-01-01

    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 ...

  12. Significance and Effect of Ecological Rehabilitation Project in Inland River Basins in Northwest China

    OpenAIRE

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

    2013-01-01

    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 quest...

  13. Petroleum Migration Direction of the Silurian Paleo-pools in the Tarim Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    LIU Luofu; LI Yan; ZHAO Yande; HUO Hong; CHEN Lixin; CHEN Yuanzhuang; ZHAO Suping; LI Chao; LI Shuangwen; GUO Yongqiang

    2008-01-01

    The results obtained in this paper indicate that carbazole-type compounds have high thermal stability and also show stability in oxidation and bio-degradation. This kind of compounds still has a high concentration and complete distribution in the analyzed dry asphalt samples, showing that they are particularly useful in studying petroleum migration of paleo-pooi. During the basin's first-stage of oil-gas pool formation in the Silurian in Tazhong and Tabei areas of Tarim Basin (at the end of Silurian period) and the second-stage in the Awati area (in Permian), the petroleum experienced a long-distance migration. During the formation of the Silurian paleo-pools in Tazhong Uplift at the end of Silurian, the petroleum mainly came from the lower and middle Cambrian source rocks in the Manjiaer sag. The petroleum migrated towards the southwest-south entering the Silurian reservoir beds in Tazhong first. Then, it further migrated within Silurian from northwest to southeast along the highs of the Structural Belts to the region of the Silurian pinchout boundary in Tazhong. In Tabei Uplift, during the first-stage of pool formation, the petroleum was also from the lower and middle Cambrian source rocks in the Manjiaer sag. It migrated northwest entering the Silurian reservoir beds in the Tabei Uplift firstly, and then the migration continued in the same direction within the Silurian reservoirs and finally the petroleum was trapped in higher positions. During the second-stage pool formation in the Silurian beds in the areas around Awati sag, the petroleum mainly came from the lower-middle Cambrian source rocks in the Awati sag. The petroleum migrated from the generation center to Silurian reservoirs in all directions around the sag through major paths, and the petroleum was finally trapped in higher locations.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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. PMID:23716005

  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. Transpiration and canopy conductance variations of shelterbelt in an arid inland river basin of northwest China

    Science.gov (United States)

    Gao, G.

    2015-12-01

    The knowledge of plant water use characteristics under changing environmental conditions is essential for ecosystem management and water resources distribution in water-stressed environments. This study was conducted to quantify variations in transpiration and canopy conductance in a shelterbelt in the middle of the Heihe River Basin, China. Sap flow of eight Gansu Poplar trees (Populus gansuensis) with different diameters at breast height (DBH) was measured over three consecutive growing seasons (2012-2014). The evapotranspiration of groundwater via plant use was estimated by the White method, with diurnal water table fluctuations. Results showed that mean sap flow density varied between 30.62 ±11.44 and 101.88 ±28.98 kg m-2 h-1, and it increased linearly with the DBH. Variations of sap flow density were mainly controlled by meteorological factors in addition to water table depth. Average stand transpiration during the growing season was about 4.85 mm day-1, and it had a logarithmic relationship with reference crop evapotranspiration. Precipitation increased stand transpiration, but not at a statistically significant level (p>0.05). The recharge of soil water by irrigation significantly accelerated stand transpiration (p<0.05). Stand transpiration and canopy conductance increased by 27% and 31%, respectively, when soil water conditions changed from dry to wet. Canopy conductance decreased logarithmically with vapor pressure deficit, whereas there was no apparent relationship between canopy conductance and solar radiation. The sensitivity of canopy conductance to vapor pressure deficit decreased under dry soil conditions. Groundwater evapotranspiration (0.6-7.1 mm day-1) was linearly correlated with stand transpiration (1.1-6.5 mm day-1) (R2 = 0.71). During the drought period, approximately 80% of total stand transpiration came from groundwater evapotranspiration. This study highlighted the critical role of irrigation and groundwater for shelterbelts, and might

  20. Estimation of subsurface formation temperature in the Tarim Basin, northwest China: implications for hydrocarbon generation and preservation

    Science.gov (United States)

    Liu, Shaowen; Lei, Xiao; Feng, Changge; Hao, Chunyan

    2016-07-01

    Subsurface formation temperature in the Tarim Basin, northwest China, is vital for assessment of hydrocarbon generation and preservation, and of geothermal energy potential. However, it has not previously been well understood, due to poor data coverage and a lack of highly accurate temperature data. Here, we combined recently acquired steady-state temperature logging data with drill stem test temperature data and measured rock thermal properties, to investigate the geothermal regime and estimate the subsurface formation temperature at depth in the range of 1000-5000 m, together with temperatures at the lower boundary of each of four major Lower Paleozoic marine source rocks buried in this basin. Results show that heat flow of the Tarim Basin ranges between 26.2 and 66.1 mW/m2, with a mean of 42.5 ± 7.6 mW/m2; the geothermal gradient at depth of 3000 m varies from 14.9 to 30.2 °C/km, with a mean of 20.7 ± 2.9 °C/km. Formation temperature estimated at the depth of 1000 m is between 29 and 41 °C, with a mean of 35 °C, while 63-100 °C is for the temperature at the depth of 3000 m with a mean of 82 °C. Temperature at 5000 m ranges from 97 to 160 °C, with a mean of 129 °C. Generally spatial patterns of the subsurface formation temperature at depth are basically similar, characterized by higher temperatures in the uplift areas and lower temperatures in the sags, which indicates the influence of basement structure and lateral variations in thermal properties on the geotemperature field. Using temperature to identify the oil window in the source rocks, most of the uplifted areas in the basin are under favorable condition for oil generation and/or preservation, whereas the sags with thick sediments are favorable for gas generation and/or preservation. We conclude that relatively low present-day geothermal regime and large burial depth of the source rocks in the Tarim Basin are favorable for hydrocarbon generation and preservation. In addition, it is found that the

  1. Estimation of subsurface formation temperature in the Tarim Basin, northwest China: implications for hydrocarbon generation and preservation

    Science.gov (United States)

    Liu, Shaowen; Lei, Xiao; Feng, Changge; Hao, Chunyan

    2015-10-01

    Subsurface formation temperature in the Tarim Basin, northwest China, is vital for assessment of hydrocarbon generation and preservation, and of geothermal energy potential. However, it has not previously been well understood, due to poor data coverage and a lack of highly accurate temperature data. Here, we combined recently acquired steady-state temperature logging data with drill stem test temperature data and measured rock thermal properties, to investigate the geothermal regime and estimate the subsurface formation temperature at depth in the range of 1000-5000 m, together with temperatures at the lower boundary of each of four major Lower Paleozoic marine source rocks buried in this basin. Results show that heat flow of the Tarim Basin ranges between 26.2 and 66.1 mW/m2, with a mean of 42.5 ± 7.6 mW/m2; the geothermal gradient at depth of 3000 m varies from 14.9 to 30.2 °C/km, with a mean of 20.7 ± 2.9 °C/km. Formation temperature estimated at the depth of 1000 m is between 29 and 41 °C, with a mean of 35 °C, while 63-100 °C is for the temperature at the depth of 3000 m with a mean of 82 °C. Temperature at 5000 m ranges from 97 to 160 °C, with a mean of 129 °C. Generally spatial patterns of the subsurface formation temperature at depth are basically similar, characterized by higher temperatures in the uplift areas and lower temperatures in the sags, which indicates the influence of basement structure and lateral variations in thermal properties on the geotemperature field. Using temperature to identify the oil window in the source rocks, most of the uplifted areas in the basin are under favorable condition for oil generation and/or preservation, whereas the sags with thick sediments are favorable for gas generation and/or preservation. We conclude that relatively low present-day geothermal regime and large burial depth of the source rocks in the Tarim Basin are favorable for hydrocarbon generation and preservation. In addition, it is found that the

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Managing stakeholders' conflicts for water reallocation from agriculture to industry in the Heihe River Basin in Northwest China.

    Science.gov (United States)

    Wang, Xiaojun; Yang, Hong; Shi, Minjun; Zhou, Dingyang; Zhang, Zhuoying

    2015-02-01

    Along with the accelerating process of industrialization and urbanization, water reallocation from agriculture to industry will be an inevitable trend in most developing countries. In the inland river basin, inter-sectoral water transfer is likely to result in reallocation of water resources between upstream and downstream regions, and further triggers frictions and conflicts between regions. Designing effective policy measures to coordinate these conflicts among stakeholders is crucial for the successful implementation of water reallocation. This study established a participatory multi-attribute decision support model to seek a widely acceptable water allocation alternative in the Heihe River Basin, an arid region in Northwest China. The results indicate that: (1) intense conflicts arise not only among stakeholder groups but also between upstream and downstream regions in the process of water reallocation from agriculture to industry; (2) among the options which respectively emphasize on equity, efficiency, and sustainability, the combination of equity and efficiency is the least controversial alternative for the majority of stakeholder groups, although it is not the most desirable one in the performance of all sub-objectives; (3) the multi-attribute value theory (MAVT) approach is a useful technique to elicit stakeholder values and to evaluate water reallocation options. The technique can improve the transparency and credibility of decision making in the water management process. PMID:25461085

  4. Characterization of groundwater in the Ejina Basin,northwest China:hydrochemical and environmental isotopes approaches

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    To characterize the groundwater in the Ejina Basin,surface and groundwater samples were collected in May and October of 2002.On-site analyses included temperature,electrical conductance(EC),total alkalinity(as HCO 3) by titration,and pH.Chemical analyses were undertaken at the Geochemistry Laboratory of the Cold and Arid Region Environmental and Engineering Institute,Chinese Academy of Sciences,Lanzhou,China.The pH of the groundwater ranged from 7.18 to 8.90 with an average value of 7.72,indicating an alkaline nature.The total dissolved solids(TDS) of the groundwater ranged from 567.5 to 5,954.4 mg/L with an average of 1,543.1 mg/L and a standard deviation of 1,471.8 mg/L.According to the groundwater salinity classification of Robinove et al.(1958),47.4 percent of the samples were brackish and the remainder were fresh water.The ion concentration of the groundwater along the riverbed and near the southern margin of the basin were lower than those farther away from the riverbed.The groundwater in the study area was of Na +-HCO 3 type near the bank of the Heihe River and in the southern margin of the basin,while Na +-SO 4 2-Cl type samples were observed in the terminal lake region.In the desert area the groundwater reached a TDS of 3,000-6,000 mg/L and was predominantly by a Na +-Cl chemistry.Br/Cl for the water of Ejina Basin indicates an evaporite origin for the groundwater with a strongly depleted Br/Cl ratio(average 0.000484).The surface water was slightly enriched in Br/Cl(average 0.000711) compared with groundwater.The calculated saturation index(SI) for calcite and dolomite of the groundwater samples range from 0.89 to 1.31 and 1.67 to 2.67 with averaged 0.24 and 0.61,respectively.About 97 percent of the groundwater samples were kinetically oversaturated with respect to calcite and dolomite,and all the samples were below the equilibrium state with gypsum.Using isotope and hydrochemical analyses,this study investigated the groundwater evolution and its residence

  5. MESOZOIC-CENOZOIC INVERSION OFTHE TURPAN-HAMI BASIN, NORTHWEST CHINA

    Institute of Scientific and Technical Information of China (English)

    CaoDaiyong; QianGuangmo; ZhangPengfei; MeiMeitang; JinKuili; TangYuegang

    1996-01-01

    The Turpan-Hami basin, rich in coal and petroleum, is a superimposedbasin of three types basins in different tectonic environments. This coal, oil and gasbasin has undergone a complex tectonic-sedimentary evolution, in which two important stages were the negative inversion from a foredeep to a extensional basin duringEarly Mesozoic and the positive inversion to a thrust foreland basin in Late MesozoicEarly Cenozoic. The early normal faults residues are recognized with the addition oftectonic-sedimentary analysis to confirm the basin extension during Jurassic time andits tectonic inversion subsequently.

  6. Geochemical Characteristics of Different Kinds of Crude Oils in the Tarim Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    朱扬明

    2001-01-01

    Based on the compositions and distributions of biomarkers in thirty-five representative oil samples, oils from the Tarim Basin of northwestern China are mainly divided into two oil families. One oil family contains relatively low amounts of C15-C20 isoprenoid hydrocarbons and shows pristane predominance with Pr/Ph ratios ranging from 1.50 to 3.00. The GC/MS analytical data of these oils show the occurrence of abundant hopanes, and low concentrations of steranes and tricyclic terpanes with hopanes/steranes ratios from 6.25 to 12.24 and tricyclic terpanes/hopanes ratios from 0.03 to 0.24. These oils contain low drimane relative to homodrimane (C15/C16< 1.0) and abundant rearranged bicyclanes in bicyclic sesquiterpanes. They are dominated by low carbon number (C19-C21) compounds in the tricyclic terpanes, and are rich in rearranged hopanes, C29Ts and an unknown C30 compound in pentacyclic triterpanes.These geochemical characteristics suggest that the oils were generated mainly from terrigenous organic matter. The other oil family shows remarkably different biomarker compositions and distributions. The oils revealed Pr/Ph ratios of about 1.0, high drimane/homodrimane ratios ( > 1.0), low hopanes/steranes ratios (0.65 - 2.50), high tricyclic terpanes/hopanes ratios (0.30 - 2.00) and a dominant peak at C23 in tricyclic tepanes, suggesting a marine organic origin. Oil-source rock correlation indicates that these two oil families seem to have been derived from Mesozoic Jurassic-Triassic terrestrial source rocks (shales and coal seams) and Lower Paleozoic Ordovician-Cambrian marine source rocks, respectively.

  7. Cation exchange capacity (Qv) estimation in shaly sand reservoirs: case studies in the Junggar Basin, northwest China

    Science.gov (United States)

    Wang, Liang; Mao, Zhi-Qiang; Sun, Zhong-Chun; Luo, Xing-Ping; Deng, Ren-Shuang; Zhang, Ya-Hui; Ren, Bing

    2015-10-01

    Cation exchange capacity (Qv) is a key parameter in resistivity-based water saturation models of shaly sand reservoirs, and the accuracy of Qv calculation is crucial to the prediction of saturations of oil and gas. In this study, a theoretical expression of Qv in terms of shaly sand permeability (Kshaly-sand), total porosity (ϕt), and salinity of formation water (S) is deduced based on the capillary tube model and the physics volume model. Meanwhile, the classical Schlumberger-Doll research (SDR) model has been introduced to estimate Kshaly-sand. On this basis, a novel technique to estimate Qv from nuclear magnetic resonance (NMR) logs is proposed, and the corresponding model is also established, whose model parameters are calibrated by laboratory Qv and NMR measurements of 15 core samples from the Toutunhe formation of the Junggar Basin, northwest China. Based on the experimental data sets, this technique can be extended to reservoir conditions to estimate continuous Qv along the intervals. The processing results of field examples illustrate that the Qv calculated from field NMR logs are consistent with the analyzed results, with the absolute errors within the scope of  ±0.1 mmol cm-3 for the majority of core samples.

  8. Petroleum geological dynamics of Lower Paleozoic in the Ordos Basin, northwest China

    Institute of Scientific and Technical Information of China (English)

    叶加仁; 赵鹏大; 陆明德

    2000-01-01

    Taking the hydrocarbon source rocks of Ordovician, Lower Paleozoic in the Ordos Basin as the main research object, the characteristics of petroleum geological dynamics about geohistory, geothermal history, hydrocarbon generation history and hydrocarbon expulsion history were studied by using the methods of basin numerical modeling dynamically and pool-forming dynamics. It is shown that the Ordovician strata had entirely undergone five stages of initial deposition, uplift and erosion, rapid subsidence, alternating uplift and subsidence, and differential uplift and erosion; that under the background of lower heat flow on the whole, the paleoheat flow of Ordovician strata in the basin could be divided into two large stages of relatively high heat flow values period before Cretaceous deposition and relatively low ones after it; that the thermal evolution of organic matters in the hydrocarbon source rocks of Ordovician had entered into high mature-postmature stage on the whole and the intensity of gas genera

  9. Synchronism of runoff response to climate change in Kaidu River Basin in Xinjiang, Northwest China

    Institute of Scientific and Technical Information of China (English)

    Jie Xue; JiaQiang Lei; DongWei Gui; JianPing Zhao; DongLei Mao; Jie Zhou

    2016-01-01

    The runoff in alpine river basins where the runoff is formed in nearby mountainous areas is mainly affected by temperature and precipitation. Based on observed annual mean temperature, annual precipitation, and runoff time-series datasets during 1958–2012 within the Kaidu River Basin, the synchronism of runoff response to climate change was analyzed and iden-tified by applying several classic methods, including standardization methods, Kendall's W test, the sequential version of the Mann-Kendall test, wavelet power spectrum analysis, and the rescaled range (R/S) approach. The concordance of the nonlinear trend variations of the annual mean temperature, annual precipitation, and runoff was tested significantly at the 0.05 level by Kendall's W method. The sequential version of the Mann-Kendall test revealed that abrupt changes in annual runoff were synchronous with those of annual mean temperature. The periodic characteristics of annual runoff were mainly consistent with annual precipitation, having synchronous 3-year significant periods and the same 6-year, 10-year, and 38-year quasi-periodicities. While the periodic characteristics of annual runoff in the Kaidu River Basin tracked well with those of annual precipitation, the abrupt changes in annual runoff were synchronous with the annual mean temperature, which directly drives glacier- and snow-melt processes. R/S analysis indicated that the annual mean temperature, annual precipitation, and runoff will continue to increase and remain synchronously persistent in the future. This work can im-prove the understanding of runoff response to regional climate change to provide a viable reference in the management of water resources in the Kaidu River Basin, a regional sustainable socio-economic development.

  10. Groundwater recharge environments and hydrogeochemical evolution in the Jiuquan Basin, Northwest China

    International Nuclear Information System (INIS)

    The groundwater recharge environments and hydrogeochemical characteristics in the Quaternary aquifer of Jiuquan Basin was investigated using a combination of chemical indicators, stable isotopes, and radiocarbon dating. The d-excess values of winter precipitation and surface water revealed that the meltwater from snow and ice played the dominant role in the basin’s surface water supply. The unconfined groundwater showed gradual enrichment of heavy isotopes along the flow path, but δ18O and δ2H values were similar to those of surface water, suggesting recent recharge as a result of rapid seepage along rivers combined with the effects of high evaporation. The 14C (pmc) values of unconfined groundwater was between 71.5% and 90.9%, and since 80% modern carbon probably represents the upper limit of initial 14C activity, this suggests that the groundwater is relatively young. The confined groundwater was depleted in heavy isotopes; coupled with low 14C values (∼20–53%), indicating that the groundwater was mainly recharged as palaeowater during the late Pleistocene and Holocene epochs under a cold climate. The surface water and most groundwater samples were fresh rather than saline, with TDS −1, respectively. The chemistry of unconfined groundwater changed from HCO3-dominated to no dominant ions and then to SO42-dominated moving along the flow path from the Jiuquan-Jiayuguan Basin to the Jinta Basin, and the confined water was SO42-dominated. The results have important implications for groundwater management in the Basin, where a high proportion of the water being used is in effect being mined (i.e., extracted faster than its replacement rate); thus, significant changes are urgently needed in the regional water-use strategy.

  11. Petroleum geological dynamics of Lower Paleozoic in the Ordos Basin, northwest China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Taking the hydrocarbon source rocks of Ordovician, Lower Paleozoic in the Ordos Basin as the main research object, the characteristics of petroleum geological dynamics about geohistory, geothermal history, hydrocarbon generation history and hydrocarbon expulsion history were studied by using the methods of basin numerical modeling dynamically and pool-forming dynamics. It is shown that the Ordovician strata had entirely undergone five stages of initial deposition, uplift and erosion, rapid subsidence, alternating uplift and subsidence, and differential uplift and erosion; that under the background of lower heat flow on the whole, the paleoheat flow of Ordovician strata in the basin could be divided into two large stages of relatively high heat flow values period before Cretaceous deposition and relatively low ones after it; that the thermal evolution of organic matters in the hydrocarbon source rocks of Ordovician had entered into high mature-postmature stage on the whole and the intensity of gas generated was greater than that of oil generated, the hydrocarbon being mainly natural gas; and that the curves of the intensity of oil and gas expulsion at each time unit showed the feature of multi-peak-type, the accumulative intensity of gas expulsion was greater than that of oil expulsion. Thus natural gas exploration potential is good.

  12. Quantification of Environmental Flow Requirements to Support Ecosystem Services of Oasis Areas: A Case Study in Tarim Basin, Northwest China

    Directory of Open Access Journals (Sweden)

    Jie Xue

    2015-10-01

    Full Text Available Recently, a wide range of quantitative research on the identification of environmental flow requirements (EFRs has been conducted. However, little focus is given to EFRs to maintain multiple ecosystem services in oasis areas. The present study quantifies the EFRs in oasis areas of Tarim Basin, Xinjiang, Northwest China on the basis of three ecosystem services: (1 maintenance of riverine ecosystem health, (2 assurance of the stability of oasis–desert ecotone and riparian (Tugai forests, and (3 restoration of oasis–desert ecotone groundwater. The identified consumptive and non-consumptive water requirements are used to quantify and determine the EFRs in Qira oasis by employing the summation and compatibility rules (maximum principle. Results indicate that the annual maximum, medium, and minimum EFRs are 0.752 × 108, 0.619 × 108, and 0.516 × 108 m3, respectively, which account for 58.75%, 48.36%, and 40.29% of the natural river runoff. The months between April and October are identified as the most important periods to maintain the EFRs. Moreover, the water requirement for groundwater restoration of the oasis–desert ecotone accounts for a large proportion, representing 48.27%, 42.32%, and 37.03% of the total EFRs at maximum, medium, and minimum levels, respectively. Therefore, to allocate the integrated EFRs, focus should be placed on the water demand of the desert vegetation’s groundwater restoration, which is crucial for maintaining desert vegetation to prevent sandstorms and soil erosion. This work provides a reference to quantify the EFRs of oasis areas in arid regions.

  13. Group classification of mixed oils in central Junggar Basin, Northwest China and their migration

    Institute of Scientific and Technical Information of China (English)

    WANG Xulong; SHI Xinpu; CAO Jian; LAN Wenfang; TAO Guoliang; HU Wenxuan; YAO Suping

    2010-01-01

    The produced oils in central Junggar Basin are commonly mixed in origin. In this paper, in order to reveal this complexity and thereby provide valuable clues to the study of oil source and formation mechanism, genetic groups of the mixed oils were classified and their migration/accumulation was investigated. Based on the artificial oil mixing experiments, some representative biomarkers of the mixed oils showed varying tendencies according to mixing ratios of the oils. Hence, these biomarkers are useful for determining the origin of the mixed oils. According to the criteria, oils in the area were divided into four basic groups, i.e., the Lower Permian Fengcheng oil, the Middle Permian Lower Wuerhe oil, the Jurassic source derived oil, and the mixed oil (including the Lower and Middle Permian mixed oil and the Permian and Jurassic mixed oil). Oil migration and accumulation were discussed in combination with the geological background.

  14. Evolution of the Moxizhuang Oil Field, Central Junggar Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    Zou Huayao; Zhang Yuanchun; Liu Jianzhang; Shi Jiannan

    2008-01-01

    Current oil saturation in the Moxizhuang (莫西庄) Oil Field in central Janggar (准噶尔) basin was evaluated by logging interpretation and measured on core samples, and the paleo-oil saturation in both the pay zones and water zones was investigated by graln-containing-oil inclusion (GOI) analysis.The pay zones in this field have low oil saturation and display low resistivity and small contrast between pay zones and water zones, and are classified as low-porosity, low oil saturation, and low resistivity reservoirs. Both the current low oil-saturation pay zones and the water zones above 4 365 m have high GOI values (up to 38%), suggesting high paleo-oil saturation. The significant difference between current oil saturation from both logging interpretation and core sample measurement and paleo-oil saturation indicated by GOI analysis suggests that this low oil-saturation field evolved from a high oil-saturation pool. Lateral re-migration and spill of formally trapped oil owing to changes in structural configuration since Neogene was the most plausible mechanism for oil loss in the Moxizhuang Oil Field.The combined effects of differential accumulation in the charge phase and the differential re-migration and spill of accumulated oil in Neogene are responsible for the complicated correlation between residual oil saturation and porosity/permeability of the reservoir sandstones and the distribution of low oil-saturation pay zones and paleo-oil zones (current water zones).

  15. The effectiveness assessment of gas accumulation processes in Kuqa depression,Tarim Basin,Northwest China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The effectiveness of gas accumulation processes is controlled by several main geological factors in-cluding charging force,features of gas conduit,sealing properties of caprock,etc. Based on the analysis and statistics of the large-medium size gas accumulations in China,the main parameters,in-cluding the excess pressure difference between the source rock and reservoir bed,the area coefficient of the gas conduit,and the thickness or displacement pressure of caprock,and the criteria for the as-sessment of gas accumulation processes have been established. Using the parameters and the criteria above,the effectiveness of gas accumulation processes in the Kuqa depression was quantitatively evaluated. By integrating the parameters of the excess pressure difference between the source rock and reservoir bed,the area coefficient of fault conduit system,and the caprock thickness in gas charging period,a comprehensive assessment of the effectiveness of gas accumulation in the Kuqa depression has been made. The result reveals that the Tubei-Dawan area,the Central Kelasu area and the Dongqiu-Dina area are three highly-effective areas for gas accumulation in the Kuqa depression.

  16. Geochemical characteristics of Tertiary saline lacustrine oils in the Western Qaidam Basin, northwest China

    International Nuclear Information System (INIS)

    Based on the systematic analyses of light hydrocarbon, saturate, aromatic fractions and C isotopes of over 40 oil samples along with related Tertiary source rocks collected from the western Qaidam basin, the geochemical characteristics of the Tertiary saline lacustrine oils in this region was investigated. The oils are characterized by bimodal n-alkane distributions with odd-to-even (C11-C17) and even-to-odd (C18-C28) predominance, low Pr/Ph (mostly lower than 0.6), high concentration of gammacerane, C35 hopane and methylated MTTCs, reflecting the high salinity and anoxic setting typical of a saline lacustrine depositional environment. Mango's K 1 values in the saline oils are highly variable (0.99-1.63), and could be associated with the facies-dependent parameters such as Pr/Ph and gammacerane indexes. Compared with other Tertiary oils, the studied Tertiary saline oils are marked by enhanced C28 sterane abundance (30% or more of C27-C29 homologues), possibly derived from halophilic algae. It is noted that the geochemical parameters of the oils in various oilfields exhibit regular spatial changes, which are consistent with the depositional phase variations of the source rocks. The oils have uncommon heavy C isotopic ratios (-24%o to -26%o) and a flat shape of the individual n-alkane isotope profile, and show isotopic characteristics similar to marine organic matter. The appearance of oleanane and high 24/(24 + 27)-norcholestane ratios (0.57-0.87) in the saline oils and source rocks confirm a Tertiary organic source

  17. The research of three-dimensional numerical simulation of groundwater-flow: taking the Ejina Basin, Northwest China as example

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Water is a primary controlling factor for economic development and ecological environmental protection in the inland river basins of arid western China. And it is groundwater, as the most important component of total water resources, that plays a dominant role in the development of western China. In recent years, the use-ratio of surface water has been raised, the groundwater recharge rate from surface water has been reduced, and groundwater has been exploited on a large scale. This has led to the decline of ground-water levels and the degradation of eco-environments in the Heihe watershed. Therefore, the study on the change in groundwater levels in recent years, as well as simulating and predicting groundwater levels in the future, have become very significant for im-proving the ecological environment of the Heihe River Basin, to coordinate the water contradiction among upper, middle and lower reaches of Heihe River Basin and to allocate the water resources. The purpose of this study is to analyze the groundwa-ter-level variations of the Ejina region based on a large scale, to develop and evaluate a conceptual groundwater model in Ejina Basin, to establish the groundwater flow model using the experimental observation data and combining Modular Three-Dimensional Groundwater Flow Model (MODFLOW) and GIS software, to simulate the regional hydrologic regime in re-cent 10 years and compare various water-delivery scenarios from midstream, and to determine which one would be the best plan for maintaining and recovering the groundwater levels and increasing the area of Ejina oasis. Finally this paper discusses the pos-sible vegetation changes of Ejina Basin in the future.

  18. Impacts of human activities and climate variability on green and blue water flows in the Heihe River Basin in Northwest China

    Science.gov (United States)

    Zang, C.; Liu, J.; Jiang, L.; Gerten, D.

    2013-07-01

    Human activities and climate factors both affect the availability of water resources and the sustainability of water management. Especially in already dry regions, water has become more and more scarce with increasing requirements from growing population, economic development and diet shifts. Although progress has been made in understanding variability of runoff, the impacts of climate variability and human activities on flows of both green water (actual evapotranspiration) and blue water (discharge accumulated in the river network) remain less well understood. We study the spatial patterns of blue and green water flows and the impacts on them of human activities and climate variability as simulated by the Soil and Water Assessment Tool (SWAT) for an inland Heihe river basin located in Northwest China. The results show that total green and blue water flow increased from 1980 to 2005, mainly as a result of climate variability (upward precipitation trends). Direct human activities did not significantly change the total green and blue water flow. However, land use change led to a transformation of 206 million m3 from green to blue water flow, while farmland irrigation expansion resulted in a transformation of 66 million m3 from blue to green water flow. The synchronous climate variability caused an increase of green water flow by 469 million m3 and an increase of blue water flow by 146 million m3 at the river basin level, while the geographical distribution showed an uneven change even with reductions of water flows in western sub-basins at midstream. The results are helpful to benchmark the water resources in the context of global change in the inland river basins in China. This study also provides a general approach to investigate the impacts of historical human activities and climate variability on green and blue water flows at the river basin level.

  19. Impacts of human activities and climate variability on green and blue water flows in the Heihe River Basin in Northwest China

    Directory of Open Access Journals (Sweden)

    C. Zang

    2013-07-01

    Full Text Available Human activities and climate factors both affect the availability of water resources and the sustainability of water management. Especially in already dry regions, water has become more and more scarce with increasing requirements from growing population, economic development and diet shifts. Although progress has been made in understanding variability of runoff, the impacts of climate variability and human activities on flows of both green water (actual evapotranspiration and blue water (discharge accumulated in the river network remain less well understood. We study the spatial patterns of blue and green water flows and the impacts on them of human activities and climate variability as simulated by the Soil and Water Assessment Tool (SWAT for an inland Heihe river basin located in Northwest China. The results show that total green and blue water flow increased from 1980 to 2005, mainly as a result of climate variability (upward precipitation trends. Direct human activities did not significantly change the total green and blue water flow. However, land use change led to a transformation of 206 million m3 from green to blue water flow, while farmland irrigation expansion resulted in a transformation of 66 million m3 from blue to green water flow. The synchronous climate variability caused an increase of green water flow by 469 million m3 and an increase of blue water flow by 146 million m3 at the river basin level, while the geographical distribution showed an uneven change even with reductions of water flows in western sub-basins at midstream. The results are helpful to benchmark the water resources in the context of global change in the inland river basins in China. This study also provides a general approach to investigate the impacts of historical human activities and climate variability on green and blue water flows at the river basin level.

  20. Petroleum geology of the northwest basin, Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Jae Hong [Yonsei University, Seoul (Korea, Republic of); Oh, Jae Ho [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of); Kim, Jong Young [Dong Won Co., Sabuk (Korea, Republic of)

    1997-06-30

    Petroleum geology of the Northwest Basin, Argentina has been studied in detail using seismic reflection profiles, drill holes and structure maps. The Northwest Basin comprises the following four successor basins that are different in characteristics and tectonic development: pre-Carboniferous, Carboniferous, Cretaceous, and Tertiary basins. Petroleum plays in the Northwest Basin can be divided into four types based on hydrocarbon-trap structures. These include thrust-folds, paleo-channels, volcanic mounds and roll-over anticlines related to normal faulting. The thrust-fold structure is a typical trap structure of pre-Carboniferous and Carboniferous basins, and consists of Cretaceous sedimentary rocks in southern exploration areas of the Northwest Basin. Paleo-channels provide a new possibility to the Carboniferous basin, and several of them occur in northern exploration areas of the Northwest Basin. Volcanic mounds and roll-over anticlines associated with the normal fault are related to the rifting event and play an important role in the Cretaceous basin. New prospects will be found if the above play types are well utilized. (author). 12 refs., 15 figs.

  1. 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.

  2. Responses of shelterbelt stand transpiration to drought and groundwater variations in an arid inland river basin of Northwest China

    Science.gov (United States)

    Shen, Qin; Gao, Guangyao; Fu, Bojie; Lü, Yihe

    2015-12-01

    Plant water use characteristics and transpiration responses under dry conditions are considered essential for effective and sustainable ecosystem management in arid areas. This study was conducted to evaluate the response of shelterbelt stand transpiration to precipitation, soil drought and groundwater variations in an oasis-desert ecotone in the middle of the Heihe River Basin, China. Sap flow was measured in eight Gansu Poplar trees (Populus Gansuensis) with different diameter at breast height over three consecutive growing seasons (2012-2014). The groundwater evapotranspiration via plant use was estimated by the White method with diurnal water table fluctuations. The results showed that precipitation increased the stand transpiration but not statistically significant (paired t-test, p > 0.05). The recharge of soil water by irrigation caused stand transpiration acceleration significantly (t-test, p evapotranspiration (0.6-7.1 mm day-1) was linearly correlated with stand transpiration (1.1-6.5 mm day-1) (R2 = 0.71), and these two variables had similar variability. During the drought period, approximately 80% of total stand transpiration came from groundwater evapotranspiration. This study highlighted the critical role of irrigation and groundwater for shelterbelt, and might provide the basis for the development of water requirement schemes for shelterbelt growth in arid inland river basins.

  3. Responses of shelterbelt stand transpiration to drought and groundwater variations in an arid inland river basin of Northwest China

    Science.gov (United States)

    Shen, Qin; Gao, Guangyao; Fu, Bojie; Lü, Yihe

    2015-12-01

    Plant water use characteristics and transpiration responses under dry conditions are considered essential for effective and sustainable ecosystem management in arid areas. This study was conducted to evaluate the response of shelterbelt stand transpiration to precipitation, soil drought and groundwater variations in an oasis-desert ecotone in the middle of the Heihe River Basin, China. Sap flow was measured in eight Gansu Poplar trees (Populus Gansuensis) with different diameter at breast height over three consecutive growing seasons (2012-2014). The groundwater evapotranspiration via plant use was estimated by the White method with diurnal water table fluctuations. The results showed that precipitation increased the stand transpiration but not statistically significant (paired t-test, p > 0.05). The recharge of soil water by irrigation caused stand transpiration acceleration significantly (t-test, p conditions changed from dry to wet. Canopy conductance decreased logarithmically with vapor pressure deficit, while there was no apparent relationship between canopy conductance and solar radiation. The sensitivity of canopy conductance to vapor pressure deficit decreased under dry soil conditions. Groundwater evapotranspiration (0.6-7.1 mm day-1) was linearly correlated with stand transpiration (1.1-6.5 mm day-1) (R2 = 0.71), and these two variables had similar variability. During the drought period, approximately 80% of total stand transpiration came from groundwater evapotranspiration. This study highlighted the critical role of irrigation and groundwater for shelterbelt, and might provide the basis for the development of water requirement schemes for shelterbelt growth in arid inland river basins.

  4. 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.

  5. Identification and Evolution of Groundwater Chemistry in the Ejin Sub-Basin of the Heihe River, Northwest China

    Institute of Scientific and Technical Information of China (English)

    SU Yong-Hong; FENG Qi; ZHU Gao-Feng; SI Jian-Hua; ZHANG Yan-Wu

    2007-01-01

    Hydro-chemical characteristics of groundwater and their changes as affected by human activities were studied in the Ejin Sub-Basin of the Inner Mongolia Autonomous Region, China, to understand the groundwater evolution, to identify the predominant geochemical processes taking place along the horizontal groundwater flow path, and to characterize anthropogenic factors affecting the groundwater environment based on previous data. The concentrations of major ions and total dissolved solids (TDS) in the groundwater showed a great variation, with 62.5% of the samples being brackish (TDS ≥ 1000 mg L-1). The groundwater system showed a gradual hydro-chemical zonation composed of Na+-HCO-3, Na+-Mg2+-SO2-4Cl-, and Na+-Cl-. The relationships among the dissolved species allowed identification of the origin of solutes and the processes that generated the observed water compositions. The dissolution of halite, dolomite, and gypsum explained, in part, the presence of Na+, K+, Cl-, SO2-4, and Ca2+, but other processes, such as mixing, Na+ exchange for Ca2+ and Mg2+, and calcite precipitation also contributed to the composition of water. Human activity, in particular large-scale water resources development associated with dramatic population growth in the last 50 years, has led to tremendous changes in the groundwater regime, which reflected in surface water runoff change, decline of groundwater table and degeneration of surface water and groundwater quality. Solving these largely anthropogenic problems requires concerted, massive and long-term efforts.

  6. Characteristics of the stem sap flux of Populus euphratica in the lower reaches of the Heihe River Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Populus euphratica trees are the sole natural perennial riparian woodlands native to the river oases in the lower reaches of Heihe River Basin in northwestern China.This study investigated characteristics of the stem sap flux of Populus euphratica and its rela-tionship to environmental factors using the thermal dissipation probe(TDP) method.The results showed that(1) daily variation of sap flow of P.euphratica on clear days exhibited an obvious unimodal curve;sap flow rates in June,July,August,and September were 13.39,12.07,12.69,and 5.10 L/d,respectively;(2) the average transpiration of the Populus euphratica from June through September amounted to 1,309.84 L;(3) stem sap flow can be affected by a number of environmental factors that,in terms of the influential degree,can be arranged in the descending order of air temperature,soil moisture,relative humidity,total solar radiation,soil temperature,and wind velocity.

  7. Temperature as a tracer to identify surface water-groundwater exchanges in the Heihe River Basin, northwest China

    Science.gov (United States)

    Liu, J.; Yao, Y.; Liu, C.; Xiao, H.; Zheng, C.; Li, W.

    2013-12-01

    The Heihe River Basin (HRB) is the second largest inland river basin in the arid region of northwestern China. Under natural conditions, the Heihe River recharges to groundwater in the piedmont areas after coming out of the Qilian Mountains. In the front edge of the alluvial and fluvial fans in the middle HRB, groundwater discharges to the surface in the form of springs and then flows into the Heihe River and ends up at the terminal lakes in the lower HRB. The surface water-groundwater interactions are frequent and dynamic along the Heihe River, and the understanding of these interactions is essential for conjunctive use and management of water resources and is fundamental to ensuring ecosystem health of the HRB. Among the various methods used to study surface water-groundwater interactions, those based on temperature have some distinct advantages because of the obvious temperature differences between surface water and groundwater and also because of the simplicity and low cost of temperature measurement. Fiber-optic distributed temperature sensing (DTS) can measure temperature at very high spatial and temporal resolutions and has led to important insights into the processes of groundwater and surface water interactions. In this study, DTS was applied to measure high-resolution temperature variations in the river water with a 0.25 m spatial interval and a 15 minute temporal frequency in a total distance of 5 km along two sections of the Heihe River. A statistical approach was used to discern the spatial distribution and the size of groundwater discharge zones and hyporheic zones, respectively. The exchange flux was then estimated using 1-D hydrodynamic model, which calculates the inflow flux in the study area by comparing the simulated temperatures with the measured ones. In addition, temperature data, combined with more traditional hydrological data such as hydraulic heads and fluxes, can provide independent constraints for calibrating the coupled surface water

  8. Effects of groundwater lateral flow on land surface processes: a case study in Heihe River Basin, north-west of China

    Science.gov (United States)

    Xie, Z.; Zeng, Y.; Yu, Y.

    2015-12-01

    As an important component of hydrologic cycle, groundwater is affected by topography, vegetation, climate condition, and anthropogenic activity. Groundwater horizontal convergence and divergence and vertical interaction with soil water result in variations of soil moisture, water and energy exchanges between the land surface and the atmosphere, which ultimately influences climate. In this work, a two-dimensional groundwater lateral flow scheme based on groundwater mass equation, is developed and incorporated into the land surface model CLM4.5 to investigate effects of groundwater lateral flow on land surface processes in a river basin. A 30-year simulation with groundwater lateral flow and a control run without the horizontal movement are conducted over Heihe River Basin, north-west China, from 1979 to 2012 using the developed model. Results show that with groundwater lateral flow, equilibrium distribution of groundwater table shows more spatial variability following topography rather than the water balance between local precipitation and evapotranspiration, and are much closer to well observations especially over middle reaches area. Along with shallower groundwater table over piedmont areas in the middle reaches, increased soil moisture is shown which alleviates the underestimation of CLM4.5 at here. Changes in evapotranspiration are occurred and it is mainly controlled by the variation of local surface soil moisture, since water is the major limitation factor of evapotranspiration over this arid area. Besides, groundwater lateral flow can change the distribution of surface runoff by changing the saturated area fraction of each model grid cell. Energy cycle also responds to the changes of hydrological cycle which redistributes the sensible heat flux and latent heat flux in the entire basin.

  9. China Northwest Architectural Design & Research Institute

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    China Northwest Architectural Design & Research Institute,founded by the state on June 1, 1952 is the first and largest architectural design institute in northwest China. For over 50 years, Northwest Institute has gradually established itself as a renowned and comprehensive design institute. It is staffed by a team of outstanding engineering design specialists able to undertake various architectural design projects from home and abroad.

  10. A model for simulating the response of runoff from the mountainous watersheds of inland river basins in the arid area of northwest China to climatic changes

    Institute of Scientific and Technical Information of China (English)

    康尔泗; 程国栋; 蓝永超; 金会军

    1999-01-01

    A model for simulating the response of monthly runoff from the mountainous watersheds to climatic changes is developed.The model is based on the modifications to the HBV runoff model, and therefore represents the characteristics and runoff generation processes of inland river basins in the arid area of northwest China. Taking the mountainous watershed of an inland river, the Heihe River originating from the Qilian Mountains and running through the Hexi Corridor as an example, the monthly runoff changes under different climate scenarios are simulated. The simulation indicates that, during the years from 1994 to 2030, if the annual mean air temperature increases by 0.5℃, and precipitation keeps unchanged, then the runoff of May and October will increase because of the increase of the snow melt runoff, but the runoff of July and August will decrease to some extent because of the increase of evaporation, and as a result, the annual runoff will decrease by 4%. If the precipitation still keeps unchanged, an

  11. Temporal variations of CO2 concentration near land surface and its response to meteorological variables in Heihe River Basin, northwest China

    Institute of Scientific and Technical Information of China (English)

    CHEN Ren-sheng; KANG Er-si; JI Xi-bin; YANG Jian-ping; ZHANG Zhi-hui; YANG Yong

    2006-01-01

    Atmospheric CO2 concentration (CC) near land surface and meteorological variables have been measured at four sites,named Yeniugou (alpine meadow and permafrost), Xishui (mountainous forest), Linze (oasis edge) and Ejina (lower desert),respectively, in Heihe River Basin, northwest China. The results showed that, the half hourly CC at night was larger than in daytime,and the daily averaged CC was the largest in winter. The averaged CC of 932 d at the Linze was about 418 ppm, was about 366 ppm in the 762 d at the Ejina. In the same period from September 23 to November 9, 2004, the averaged CC was about 625,334, 436 and 353 ppm, at Yeniugou, Xishui, Linze and Ejina, respectively. The linear relationship between daily averaged CC and air temperature T was negative, between CC and relative humidity (RH) was positive. The linear CC-atmospheric pressure (A P) relationship was negative at the Linze and Yeniugou, was positive at the Ejina. The relationship between CC and global radiation R was exponent, and soil temperature Ts was negative linear, and soil water content was complex. The correlation between CC and wind speed was not existent.Using meteorological variables together to simulate CC, could give good results.

  12. Analysis of Water Resources Supply and Demand and Security of Water Resources Development in Irrigation Regions of the Middle Reaches of the Heihe River Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    JI Xi-bin; KANG Er-si; CHEN Ren-sheng; ZHAO Wen-zhi; XIAO Sheng-chun; JIN Bo-wen

    2006-01-01

    Based on the data for meteorology, hydrology, soil, planting, vegetation, and socio-economic development of the irrigation region in the middle reaches of the Heihe River basin, Northwest China, the model of balance of water supply and demand in the region was established, and the security of water resource was assessed, from which the results that the effects of unified management of water resources in the Heihe River basin between Gansu Province and Inner Mongolia on regional hydrology are significant with a decrease in water supply diverted from Heihe River and an increase in groundwater extracted. In addition, it was found that the groundwater level has been steadily decreasing due to over pumping and decrease in recharges. In present year (2003), the volume of potential groundwater in the irrigation districts is far small because of the groundwater overdraft; even in the particular regions, there is no availability of groundwater resources for use. By 2003, water supply is not sufficient to meet the water demand in the different irrigation districts, the sustainable development and utilization of water resources are not secured, and the water supply crisis occurs in Pingchuan irrigation district. Achieving water security for the sustainable development of society, agriculture, economy, industry, and livelihoods while maintaining or improving the abilities of the management and planning of water resources, determining of the reasonable percentage between water supply and groundwater utilization and water saving in agricultural irrigation are taken into account. If this does not occur, it is feared that the present performance of water development and planning may further aggravate the problem of scarcities of water resources and further damage the fragile ecological system.

  13. The land use change characteristics and its driving force analysis of Shiyang river basin in northwest China

    Science.gov (United States)

    Han, Tao; Xie, Yaowen; Jiang, Youyan

    2015-12-01

    In the paper, the use of 1994 and 2005 Landsat TM data monitors the land use and changes of the Shiyang river basin with remote sensing classification comparison under the support of GIS. The result shows that from 1994 to 2005, the area of farmland and settlement land increased greatly and that of grass and forest reduces obviously in this basin; Minqin which is in the lower reaches of Shiyang river basin has a serious desertification with low grass coverage degradation into desert. With a comprehensive analysis about the driving factors of nature and human, population pressure and irrational use of water resource are the key factors of the Land use change and between the natural factor and human factor, human acts leading role.

  14. 内陆河流域用水结构与产业结构双向优化仿真模型%Mutual optimization of water utilization structure and industrial structure in arid inland river basins of Northwest China

    Institute of Scientific and Technical Information of China (English)

    鲍超; 方创琳; 陈凡

    2006-01-01

    Water is a key restricting factor of the economic development and eco-environmental protection in arid inland river basins of Northwest China. Although water supplies are short, the water utilization structure and the corresponding industrial structure are unbalanced. We constructed a System Dynamic Model for mutual optimization based on the mechanism of their interaction. This model is applied to the Heihe River Basin where the share of limited water resources among ecosystem, production and human living is optimized. Results show that, by mutual optimization, the water utilization structure and the industrial structures fit in with each other. And the relationships between the upper, middle and lower reaches of the Heihe River Basin can be harmonized. Mutual benefits of ecology, society and economy can be reached, and a sustainable ecology-production-living system can be obtained. This study gives a new insight and method for the sustainable utilization of water resources in arid inland river basins.

  15. Microfacies and depositional environments of the Late Ordovician Lianglitage Formation at the Tazhong Uplift in the Tarim Basin of Northwest China

    Science.gov (United States)

    Gao, Da; Lin, Changsong; Yang, Haijun; Zuo, Fanfan; Cai, Zhenzhong; Zhang, Lijuan; Liu, Jingyan; Li, Hong

    2014-04-01

    The Late Ordovician Lianglitage Formation comprises 13 microfacies (Mf1-Mf13) that were deposited on a carbonate platform at the Tazhong Uplift of the Tarim Basin in Northwest China. Each type of microfacies indicates a specific depositional environment with a certain level of wave energy. Four primary groups of microfacies associations (MA1-MA4) were determined. These associations represent different depositional facies, including reef-shoal facies in the platform margin (MA1), carbonate sand shoal facies (MA2) and oncoid shoal (MA3) on open platforms, and lagoon and tidal flat facies (MA4) in the platform interior. Each microfacies association was generated in a fourth-order sedimentary sequence developing within third-order sequences (SQ1, SQ2, and SQ3, from bottom to top), showing a shallowing-upward trend. High-frequency sequences and facies correlation between wells suggests that the reef-shoal facies more successively developed in the southeastern part of the platform margin, and high-energy microfacies were more strictly confined by the top boundary of fourth-order sequences in the northwestern part of the platform. The highstand systems tract (HST) of the SQ2 is characterized by reef-shoals that developed along the platform margin and tidal flats and lagoons that developed in the platform interior, while the SQ3 is characterized by the oncoid shoal facies that generally developed on the uplift due to a regionally extensive transgression that occurred during the latter part of the Late Ordovician. The results of this study can be used for investigating the development and distribution of potential reservoirs; the reservoirs in southeastern part of the platform margin may be of premium quality because the high-energy microfacies were best preserved there.

  16. Differences in changes of potential evaporation in the mountainous and oasis regions of the Tarim basin, northwest China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Data from eleven meteorological stations in the Tianshan mountains and the north slope of west Kunlun mountains, and eighteen meteorological stations in the Kaidu-Kongque river, Akesu river, Kashiger river and Yankant river oases were examined to assess the differences in changes in potential evaporation from 1960 to 2006 in the mountainous and oasis regions of the Tarim basin and the relationships of these changes to meteorological factors. The decreasing trends in potential evaporation were primarily due to the decrease in the aerodynamic terms in both the mountainous and oasis regions, but the trends in the oasis regions were more pronounced. Based on the complementary relationship between potential and actual evaporation, the decreasing trends in potential evaporation appeared to be related to the increasing trends in precipitation in the mountainous regions and the increasing trends in water consumption in the oasis regions, thus reflecting the different impacts of natural changes and anthropogenic influences.

  17. Differences in chanses of potential evaporation in the mountainous and oasis regions of the Tarim basin, northwest China

    Institute of Scientific and Technical Information of China (English)

    HAN SongJun; HU HePing; YANG DaWen; LIU QunChang

    2009-01-01

    Data from eleven meteorological stations in the Tianshan mountains and the north slope of west Kunlun mountains, and eighteen meteorological stations in the Keidu- Kongque river, Akesu river, Kashiger river and Yankant river oases were examined to assess the differences in changes in potential evaporation from 1960 to 2006 in the mountainous and oasis regions of the Tarim basin and the relationships of these changes to meteorological factors. The decreasing trends in potential evaporation were primarily due to the decrease in the aerodynamic terms in both the mountainous and oasis regions, but the trends in the oasis regions were more pronounced. Based on the complementary relationship between potential and actual evaporation, the decreasing trends in potential evaporation appeared to be related to the increasing trends in precipitation in the mountainous regions and the increasing trends in water consumption in the oasis regions, thus reflecting the different impacts of natural changes and anthropogenic influences.

  18. Quantitative assessment of gas washing of oils in the Tazhong area of the Tarim Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    YANG ChuPeng; GENG AnSong; LIAO ZeWen; SUN YongGe; ZHANG LüHui

    2009-01-01

    Gas washing has been known in the Tazhong area of the Tarim Basin, but its quantitative assessment has not yet been reported. Here the influence of gas washing fractionation in the area was discussed based on the gas chromatogram data of 68 oils and the results of the mixing experiments of a black oil and a condensate. The results show that the intensity of gas washing fractionation decreased generally from northern to southern part and vertically from deep reservoirs to shallow reservoirs. The gas washing fractionation was mainly controlled by fault systems in this area, with the increase of n-alkane mass depletion positively correlated to the number and scale of faults. Gas washing fractionation ap-pears to have affected the hydrocarbon property, and as a result the diversity of the crude oils is markedly controlled by gas washing. In addition, the occurrence of waxy oil in this area may be re-sulted from multiple factors including gas washing, mixed filling and migration fractionation.

  19. Quantitative assessment of gas washing of oils in the Tazhong area of the Tarim Basin,Northwest China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Gas washing has been known in the Tazhong area of the Tarim Basin,but its quantitative assessment has not yet been reported.Here the influence of gas washing fractionation in the area was discussed based on the gas chromatogram data of 68 oils and the results of the mixing experiments of a black oil and a condensate.The results show that the intensity of gas washing fractionation decreased generally from northern to southern part and vertically from deep reservoirs to shallow reservoirs.The gas washing fractionation was mainly controlled by fault systems in this area,with the increase of n-alkane mass depletion positively correlated to the number and scale of faults.Gas washing fractionation appears to have affected the hydrocarbon property,and as a result the diversity of the crude oils is markedly controlled by gas washing.In addition,the occurrence of waxy oil in this area may be resulted from multiple factors including gas washing,mixed filling and migration fractionation.

  20. Simulation of energy and water balance in Soil-Vegetation- Atmosphere Transfer system in the mountain area of Heihe River Basin at Hexi Corridor of northwest China

    Institute of Scientific and Technical Information of China (English)

    KANG Ersi; CHENG Guodong; SONG Kechao; JIN Bowen; LIU Xiande; WANG Jinye

    2005-01-01

    In the mountain area of inland Heihe River Basin at Hexi Corridor of northwest China during the vegetation growing season from May to September, the Simultaneous Heat and Water (SHAW) model of Soil-Vegetation-Atmosphere Transfer (SVAT) system is applied to simulating and studying energy and water balance of the soil-residue-plant canopy layers in the Picea crassifolia forest and the grassland by the forest at the shaded slope and the grassland at the sun-facing slope. The simulation of energy balance indicates that net radiation of the grassland at the sun-facing slope is more than that of the Picea crassifolia forest and the grassland by the forest at the shaded slope. The energy outgoing components are the first latent heat and next sensible heat from the grassland both at the shaded slope and the sun-facing slope, but those at the former are less. The energy outgoing components are the first sensible heat and next latent heat from the Picea crassifolia forest. The composition and distribution of energy in the soil-residue-plant canopy layers in the Picea crassifolia forest and the grassland by the forest at the shaded slope make the soil layer receive less energy, which therefore, especially the forest possesses the energy conditions for soil water conservation. The simulation of water balance indicates that the water loss of the grassland at the sun-facing slope is mainly caused by soil evaporation, while evapotranspiration of the Picea crassifolia forest and the grassland by the forest at the shaded slope is less than that of the grassland at the sun-facing slope. Half of the evapotranspiration of the Picea crassifolia forest and the grassland by the forest at the shaded slope is consumed by transpiration. After precipitation, the soil water storage is increased much more for the Picea crassifolia forest and also more for the grassland by the forest at the shaded slope. Therefore the shaded slope vegetation, especially the forest is favorable for soil water

  1. The disastrous effects of salt dust deposition on cotton leaf photosynthesis and the cell physiological properties in the Ebinur Basin in Northwest China.

    Directory of Open Access Journals (Sweden)

    Jilili Abuduwaili

    Full Text Available 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. (3The 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. (4Salt 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

  2. Formation mechanism of the Qiongdongnan basin northwest of the South China Sea-dating the sinistral slip of the Red River Fault Zone

    Science.gov (United States)

    Sun, Z.; Jiang, J.; Xie, W.

    2010-12-01

    Locating on the northwestern margin of the South China Sea, the Qiongdongnan basin is a NE-trending rift zone in general. Bounding with the NW-trending Yinggehai basin and the Red River- East Vietnam Fault Zone to the west, the evolution of the Qiongdongnan basin bears large amounts of information about the slip of the Red River Fault zone. Combined the geological analysis with analogue modeling experiments, we suggest that the evolution of the Qiongdongnan is controlled not only by the southeastward to south southeastward extension, but also by the sinistral slip of the Red River Fault zone. The central depression of the Qiongdongnan basin is controlled mainly by the southeastward to south southeastward extension, while the southern depression developed under the combined stress filed of southeastward extension and the dextral slip along the NNW-trending Red River fault zone. The northern depression was formed by the combined effect of the sinistral slip along the Red River Fault Zone and the southeastward extension. According to the age of the shear fault starting to develop in the southwest of the Qiongdongnan basin, as well as the age for the northwestern part to develop, the sinistral slip of the Red River Fault zone began around early oligocene, later than the rifting of the Qiongdongnan basin. The sinistral slip rate of the Red River Fault zone during early Oligocene may be smaller than the displacement rate of the Qiongdongnan basin, but become reversed thereafter, which in turn caused tectonic inversion and folding along the western segment of the Qiongdongnan basin, and NW- to NNW-trending Rediel faults from late Oligocene to middle Miocene. Through the deformation history of the Qiongdongnan basin, we defined the sinistral slip stage Indochina along the Red River Fault zone from about 36Ma to 16Ma, and further a rapid slip occurring after 30Ma.

  3. China's Qaidam Basin Sensitive to Global Warming

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Chinese meteorologists recently pointed out that the temperatures in northwest China's resource-rich Qaidam Basin are rising faster than the rest of the country as a result of climate change.The rapid rise in temperatures is likely to increase the long-term frequency of droughts and farming pests in the basin to the northeast of the Qinghai-Tibet Plateau.Qaidam Basin covers 250,000 km2 in Qinghai Province and is known as resource-rich with salt lakes,petroleum,natural gas and other abundant mineral resources.

  4. Validation and Performance Evaluations of Methods for Estimating Land Surface Temperatures from ASTER Data in the Middle Reach of the Heihe River Basin, Northwest China

    OpenAIRE

    Ji Zhou; Mingsong Li; Shaomin Liu; Zhenzhen Jia; Yanfei Ma

    2015-01-01

    Validation and performance evaluations are beneficial for developing methods that estimate the remotely sensed land surface temperature (LST). However, such evaluations for Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data are rare. By selecting the middle reach of the Heihe River basin (HRB), China, as the study area, the atmospheric correction (AC), mono-window (MW), single-channel (SC), and split-window (SW) methods were evaluated based on in situ measured LSTs. ...

  5. Evolution of the groundwater system under the impacts of human activities in middle reaches of Heihe River Basin (Northwest China) from 1985 to 2013

    Science.gov (United States)

    Mi, Lina; Xiao, Honglang; Zhang, Jianming; Yin, Zhenliang; Shen, Yongping

    2016-06-01

    Investigation of the evolution of the groundwater system and its mechanisms is critical to the sustainable management of water in river basins. Temporal and spatial distributions and characteristics of groundwater have undergone a tremendous change with the intensity of human activities in the middle reaches of the Heihe River Basin (HRB), the second largest arid inland river basin in northwestern China. Based on groundwater observation data, hydrogeological data, meteorological data and irrigation statistical data, combined with geostatistical analyses and groundwater storage estimation, the basin-scaled evolution of the groundwater levels and storage (from 1985 to 2013) were investigated. The results showed that the unbalanced allocation of water sources and expanded cropland by policy-based human activities resulted in the over-abstraction of groundwater, which induced a general decrease in the water table and groundwater storage. The groundwater level has generally fallen from 4.92 to 11.49 m from 1985 to 2013, especially in the upper and middle parts of the alluvial fan (zone I), and reached a maximum depth of 17.41 m. The total groundwater storage decreased by 177.52 × 108 m3; zone I accounted for about 94.7 % of the total decrease. The groundwater balance was disrupted and the groundwater system was in a severe negative balance; it was noted that the groundwater/surface-water interaction was also deeply affected. It is essential to develop a rational plan for integration and management of surface water and groundwater resources in the HRB.

  6. Evolution of the groundwater system under the impacts of human activities in middle reaches of Heihe River Basin (Northwest China) from 1985 to 2013

    Science.gov (United States)

    Mi, Lina; Xiao, Honglang; Zhang, Jianming; Yin, Zhenliang; Shen, Yongping

    2016-01-01

    Investigation of the evolution of the groundwater system and its mechanisms is critical to the sustainable management of water in river basins. Temporal and spatial distributions and characteristics of groundwater have undergone a tremendous change with the intensity of human activities in the middle reaches of the Heihe River Basin (HRB), the second largest arid inland river basin in northwestern China. Based on groundwater observation data, hydrogeological data, meteorological data and irrigation statistical data, combined with geostatistical analyses and groundwater storage estimation, the basin-scaled evolution of the groundwater levels and storage (from 1985 to 2013) were investigated. The results showed that the unbalanced allocation of water sources and expanded cropland by policy-based human activities resulted in the over-abstraction of groundwater, which induced a general decrease in the water table and groundwater storage. The groundwater level has generally fallen from 4.92 to 11.49 m from 1985 to 2013, especially in the upper and middle parts of the alluvial fan (zone I), and reached a maximum depth of 17.41 m. The total groundwater storage decreased by 177.52 × 108 m3; zone I accounted for about 94.7 % of the total decrease. The groundwater balance was disrupted and the groundwater system was in a severe negative balance; it was noted that the groundwater/surface-water interaction was also deeply affected. It is essential to develop a rational plan for integration and management of surface water and groundwater resources in the HRB.

  7. 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 river basin.

  8. Middle-Upper Ordovician (Darriwilian-Early Katian) Positive Carbon Isotope Excursions in the Northern Tarim Basin, Northwest China:Implications for Stratigraphic Correlation and Paleoclimate

    Institute of Scientific and Technical Information of China (English)

    Cunge Liu; Guorong Li; Dawei Wang; Yongli Liu; Mingxia Luo; Xiaoming Shao

    2016-01-01

    ABSTRACT:Three positive carbon isotope excursions are reported from Middle–Upper Ordovician in Tahe oil-gas field, northern Tarim Basin. Based on conodont biostratigraphy, the Middle Darriwilian Isotope Carbon Excursion (MDICE) and the Guttenberg Carbon Isotope Excursion (GICE) are identified from Darriwilian to Early Katian by the aid of whole-rock carbon isotope data from two well cores. Positive excursion within conodont Pygodus anserinus zone is developed in Early Sandbian, and the fluctuation range is no less than MDICE. Because the range of this excursion in the generalized global carbon isotope curve is short, previous studies paid little attention to it, and named Early Sandbian Isotope Carbon Excursion (ESICE) in this paper. Furthermore, these positive excursions are not directly related to sea level fluctuations and the MDICE and GICE identified in northern Tarim can be globally correlated to that in southern China, North America, South America, and Europe. The Saergan Fm. source rocks of Middle-Upper Ordovician in Kalpin Dawangou outcrop are in accord with the geologic time of MDICE and ESICE, and GICE have strong ties to the source rock of Lianglitag Fm. in basin. Abundant organic carbon burial is an important factor in genesis of positive isotope carbon excursions. Positive oxygen isotope excursion, conodont fauna turnover, decreased conodont total diversity, and the change of sedimentary facies indicated that dramatic changes of paleoceanographic environment of Early-Middle Ordovician in Tarim Basin started from the end of Darriwillian, and an obvious icehouse climate of Late Ordovician occurred in ESICE.

  9. CHARACTERISTIC ASPECTS OF THE NORTHWEST BALTIC REGION SEA BASIN

    OpenAIRE

    Zhelezkova, Polina

    2014-01-01

    This work covers the characteristic features of the port infrastructure development in the Northwest of the Baltic basin. The ports specialization is emphasized. Following the results, a need to build multimodal terminal and logistic complexes (hubs) was found.

  10. Using the nonlinear aquifer storage–discharge relationship to simulate the baseflow of glacier and snowmelt dominated basins in Northwest China

    Directory of Open Access Journals (Sweden)

    R. Gan

    2013-04-01

    Full Text Available Baseflow is an important component in hydrological modeling. This process is usually modeled by using the linear aquifer storage–discharge relation approach, although the outflow from groundwater aquifers is nonlinear. To identify the accuracy of baseflow estimates in rivers dominated by snow and/or glacier melt in arid and cold northwestern China, a nonlinear storage–discharge relationship for use in SWAT (Soil Water Assessment Tools modeling was developed and applied to the Manas River basin in the Tianshan Mountains. Linear reservoir models and a digital filter program were used for comparisons. Meanwhile, numerical analysis of flow recession curves from 78 river gauge stations revealed variation in the coefficients of the nonlinear relationship. It was found that the nonlinear reservoir model can improve the streamflow simulation, especially for low-flows. The highest Nash–Sutcliff efficiency and lowest Percent Bias were obtained when compared to the one- or two-linear reservoir approach. The exponent b of the aquifer storage–discharge function varied mostly between 0.0 and 0.1, which is much smaller than the suggested value of 0.5. The coefficient a of the function is related to catchment properties, primarily the basin and glacier areas.

  11. Using the nonlinear aquifer storage–discharge relationship to simulate the base flow of glacier- and snowmelt-dominated basins in northwest China

    Directory of Open Access Journals (Sweden)

    R. Gan

    2013-09-01

    Full Text Available Base flow is an important component in hydrological modeling. This process is usually modeled by using the linear aquifer storage–discharge relation approach, although the outflow from groundwater aquifers is nonlinear. To identify the accuracy of base flow estimates in rivers dominated by snowmelt and/or glacier melt in arid and cold northwestern China, a nonlinear storage–discharge relationship for use in SWAT (Soil Water Assessment Tool modeling was developed and applied to the Manas River basin in the Tian Shan Mountains. Linear reservoir models and a digital filter program were used for comparisons. Meanwhile, numerical analysis of recession curves from 78 river gauge stations revealed variation in the parameters of the nonlinear relationship. It was found that the nonlinear reservoir model can improve the streamflow simulation, especially for low-flow period. The higher Nash–Sutcliffe efficiency, logarithmic efficiency, and volumetric efficiency, and lower percent bias were obtained when compared to the one-linear reservoir approach. The parameter b of the aquifer storage–discharge function varied mostly between 0.0 and 0.1, which is much smaller than the suggested value of 0.5. The coefficient a of the function is related to catchment properties, primarily the basin and glacier areas.

  12. 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 < 0.05) for the land use pattern, whereas such a relationship was not found in the three land use types. The spatial pattern of the SWC was more time stable for the land use pattern, followed by desert, shelterbelt, and cropland. The spatial pattern of SWC changed dramatically among different soil layers. The locations representing the mean SWC varied with the depth, and no location could represent the whole soil profile due to different soil texture, root distribution and irrigation management. The representative locations of each soil layer could be used to estimate the mean SWC well. The 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.

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

    International Nuclear Information System (INIS)

    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

  14. 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.

  15. Validation and Performance Evaluations of Methods for Estimating Land Surface Temperatures from ASTER Data in the Middle Reach of the Heihe River Basin, Northwest China

    Directory of Open Access Journals (Sweden)

    Ji Zhou

    2015-05-01

    Full Text Available Validation and performance evaluations are beneficial for developing methods that estimate the remotely sensed land surface temperature (LST. However, such evaluations for Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER data are rare. By selecting the middle reach of the Heihe River basin (HRB, China, as the study area, the atmospheric correction (AC, mono-window (MW, single-channel (SC, and split-window (SW methods were evaluated based on in situ measured LSTs. Results demonstrate that the influences of surface heterogeneity on the validation are significant in the study area. For the AC, MW, and SC methods, the LSTs estimated from channel 13 are more accurate than those from channel 14 in general cases. When the in situ measured atmospheric profiles are available, the AC method has the highest accuracy, with a root-mean squared error (RMSE of about 1.4–1.5 K at the homogenous oasis sites. In actual application without sufficient in situ measured inputs, the MW method is highly accurate; the RMSE is around 1.5–1.6 K. The SC method systematically overestimates LSTs and it is sensitive to error in the water vapor content. The two SW methods are simple to use but their performances are limited by accuracies, revealed by the simulation dataset. Therefore, when the in situ atmospheric profiles are available, the AC method is recommended to generate reliable ASTER LSTs for modeling the eco-hydrological processes in the middle reach of the HRB. When sufficient in situ measured inputs are not available, the MW method can be used instead.

  16. The influence of precipitation and temperature input schemes on hydrological simulations of a snow and glacier melt dominated basin in Northwest China

    Directory of Open Access Journals (Sweden)

    X. Ji

    2013-01-01

    Full Text Available Basins with glaciers and snow provide water storage and supply for downstream irrigated farmland, but their hydrology is often poorly known because there are limited observation networks in high mountain regions. Large uncertainties in hydrological simulations also arise from errors associated with meteorological forcing data. The influence of precipitation and temperature forcing data on hydrological simulations in rain/snow dominated watershed is well documented, but less so in basins with glaciers. We analyzed the impacts and reliability of precipitation/temperature input solutions on hydrological simulations in the glacier/snow dominated Manas River Basin, showing that precipitation pattern has significant impact on snow accumulation and melt, and further impacts on simulated glacier melt behavior. The temperature inputs affect not only the timing of discharge but also the total water yield. The uncertainty associated with simple estimated input data propagates and is amplified through the modeling process. We suggest that the impacts of forcing data on hydrological simulations in basins with glaciers are more complex than in common rain/snow dominated watersheds. Glacier melt behavior may conceal uncertainties that are actually derived from input data. Assessment of hydrological model performance should include investigation of key processes involved in the hydrologic cycle individually, not just comparisons of simulated and observed discharge.

  17. Northwest China covered by 750-kV power grid

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Being abundant in hydropower, coal, wind energy and solar energy etc., Northwest China is an important energy base with great potential. In recent years, along with the vigorous development of the energy base, the

  18. Using the nonlinear aquifer storage–discharge relationship to simulate the base flow of glacier- and snowmelt-dominated basins in northwest China

    OpenAIRE

    Gan, R.; Luo, Y.

    2013-01-01

    Base flow is an important component in hydrological modeling. This process is usually modeled by using the linear aquifer storage–discharge relation approach, although the outflow from groundwater aquifers is nonlinear. To identify the accuracy of base flow estimates in rivers dominated by snowmelt and/or glacier melt in arid and cold northwestern China, a nonlinear storage–discharge relationship for use in SWAT (Soil Water Assessment Tool) modeling was developed and applied to the Manas Rive...

  19. Using the nonlinear aquifer storage–discharge relationship to simulate the baseflow of glacier and snowmelt dominated basins in Northwest China

    OpenAIRE

    Gan, R.; Luo, Y.

    2013-01-01

    Baseflow is an important component in hydrological modeling. This process is usually modeled by using the linear aquifer storage–discharge relation approach, although the outflow from groundwater aquifers is nonlinear. To identify the accuracy of baseflow estimates in rivers dominated by snow and/or glacier melt in arid and cold northwestern China, a nonlinear storage–discharge relationship for use in SWAT (Soil Water Assessment Tools) modeling was developed and applied to the Manas River bas...

  20. Geochemical characteristics and genetic types of crude oils from the Tertiary system in the southern part of western Qaidam Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    LI Hongbo; ZHANG Min; ZHANG Chunming; PENG Dehua

    2008-01-01

    Crude oil samples taken from the southern part of westem Qaidam Basin were analyzed with GC/MS in order to understand the geochemical characteristics of crude oils. The results reveal that most crude oils are characterized by high abundance of gammaeerane and C35 homohopane, which are the representative characteristics of saline lacustrine crude oils. Based on the variation of the ratios of gammacerane/C30 hopane (G/H) and C35 homohopane/C34 homohopane (C35/C34H), two crude oil groups, A and B, are identified. Group-A crude oils mainly occurr in the north of the study area, with higher ratios of G/H (>0.8) and C35/C34H (>1.2), whereas group-B crude oils, selected from the south of the study area, show lower ratios of G/H (<0.8) and C35/C3aH (<1.0). In addition, group-A crude oils are distinguished into three subgroups in accordance with their different ratios of G/H and C35/C34H and different distribution characteristics of n-alkanes, isoprenoids and steranes. These may be helpful for understanding the distribution characteristics of crude oils in the southern part of western Qaidam Basin and providing clues to the forthcoming exploration of crude oils and gas.

  1. 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

    OpenAIRE

    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 Ba...

  2. Alpine Glacier Change in the Eastern Altun Mountains of Northwest China during 1972-2010

    OpenAIRE

    Xinyang Yu; Changhe Lu

    2015-01-01

    Accurately mapping and monitoring glacier changes over decades is important for providing information to support sustainable use of water resource in arid regions of northwest China. Since 1970, glaciers in the Eastern Altun Mountains showed remarkable recession. Further study is indispensable to indicate the extent and amplitude of glacial change at basin and individual glacier scale. In this study, spatiotemporal glacier changes referring to the year 1972, 1990, 2000 and 2010 were studied f...

  3. Tectonic evolution of Kashmir basin in northwest Himalayas

    Science.gov (United States)

    Alam, Akhtar; Ahmad, Shabir; Bhat, M. Sultan; Ahmad, Bashir

    2015-06-01

    Geomorphology has long been recognised as a key to evaluate the interplay between tectonics and landscape geometry in the regions of active deformation. We use geomorphic signatures at varied spatial scales interpreted from SRTM-DEM/Landsat-ETM data, supplemented with field observations to review the tectonic evolution of Kashmir basin in northwest Himalayas. Geomorphic evidence is persuasive of a credible NNW-SSE trending dextral strike-slip structure (central Kashmir Fault - CKF), with the strike length of ~ 165 km, stretched centrally over the NNW-SSE length of the Kashmir basin. As a result of the strike-slip motion and subsequent erosion, significant deformation has taken place along the CKF. In addition, broad geomorphic architecture of the basin reveals typical pull-apart characteristics. Hence, we deduce that the Kashmir basin has evolved as a pull-apart Quaternary sediment depression owing to the deformation along the central Kashmir Fault. The spatial distribution pattern of seismic events (NEIC-catalogue, 1973-2013) and GPS measurements (published), collectively substantiate our geomorphic interpretations.

  4. 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…

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

    OpenAIRE

    Zhiyong Wu; Heng Xiao; Guihua Lu; Jinming Chen

    2015-01-01

    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 temperat...

  6. Implementing Integrated River Basin Management in China

    Directory of Open Access Journals (Sweden)

    Lifeng Li

    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.

  7. Appropriate Strategies for Rural Houses In Northwest China

    Institute of Scientific and Technical Information of China (English)

    HE Quan; LIU Jia-ping; LU Xiao-hui; YANG Liu

    2009-01-01

    To avoid the old road of urban development with high consumption and high pollution,this paper took the houses in a village near Yinchuan(a typical city of Northwest China)as an exemplary proiect to explore the appropriate strategies in the arid cold climate for the sustainable devdopment in rural undeveloped areas Northwest China.Firstly,all houses were designed according to the principles of passive solar heating.Second-ly,optimized biomass energy technologies such as biogas pit and straw gasification stove were utilized for cooking or heating.Last but not the least important,the ecological building materials such as earth,straw bale,fly ash were used to construct houses,which improves the indoor thermal comfort and meanwhile lowers the negative impact on the environment.Low costs,easy accessibility and habitants'inclination were taken into account in the process of design.

  8. Estimation of regional evapotranspiration over Northwest China using remote sensing

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It is a very complicated problem to estimate evapotranspiration (ET) over a large area of land surface. In this paper, the evapotranspiration estimation models for dense vegetation and bare soil are presented, based on the information of parameters like vegetation cover-degree and surface albedo. Combined with vegetation cover-degree data, a model for regional evapotranspiration estimation over the heterogeneous landscape is derived. Through a case study using remote sensing data over Northwest China, the accuracy of the model for regional evapotranspiration estimation is checked. The result shows that the accuracy of the model is satisfactory. The features of evapotranspiration over Northwest China are also discussed with the application of the model.

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

    International Nuclear Information System (INIS)

    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)

  10. Hydrologic modeling of the Heihe watershed by DLBRM in Northwest China

    Institute of Scientific and Technical Information of China (English)

    Carlo; Demarchi; Thomas; E.Croley; Ⅱ; Tim; Hunter

    2009-01-01

    Water shortage is a chronic problem in arid Northwest China.The rapid population growth and expanding urbanization as well as potential climate change impacts are likely to worsen the situation,threatening domestic,irrigation,and industrial supplies and even the survival of the ecosystems in Northwest China.This paper describes the preliminary work of adapting the Distributed Large Basin Runoff Model(DLBRM) to the Heihe watershed(the second largest inland river in arid Northwestern China,with a drainage area of 128,000 km2) for understanding distribution of glacial-snow melt,groundwater,surface runoff,and evapotranspi-ration,and for assessing hydrological impacts of climate change and glacial recession on water supply in the middle and lower reaches of the watershed.Preliminary simulation results show that the Qilian Mountain in the upper reach area produces most runoff in the Heihe watershed.The simulated daily river flows during the period of 1990-2000 indicate that the Heihe River dis-charges about 1×109 m3 of water from the middle reach(at Zhengyixia Station) to lower reach,with surface runoff and interflow contributing 51 and 49 percent respectively.The sandy lower soil zone in the middle reach has the highest evapotranspiration rate and also contributes nearly half of the river flow.Work underway focuses on the DLBRM model improvement and incorporation of the climate change and management scenarios to the hydrological simulations in the watershed.

  11. Climate Change Impacts and Adaptation Strategies in Northwest China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hong-Yan; LIU Cai-Hong; LI Yan-Chun; FANG Jian-Gang; LI Lin; LI Hong-Mei; ZHENG Guang-Fen; DENG Zhen-Yong; DONG An-Xiang; GUO Jun-Qin; ZHANG Cun-Jie; SUN Lan-Dong; ZHANG Xu-Dong; LIN Jing-Jing; WANG You-Heng; FANG Feng; MA Peng-Li

    2014-01-01

    Climate change resulted in changes in crop growth duration and planting structure, northward movement of planting region, and more severe plant diseases and insect pests in Northwest China. It caused earlier seeding for spring crop, later seeding for autumn crop, accelerated crop growth, and reduced mortality for winter crop. To adapt to climate change, measures such as optimization of agricultural arrangement, adjustment of planting structure, expansion of thermophilic crops, and development of water-saving agriculture have been taken. Damaging consequences of imbalance between grassland and livestock were enhanced. The deterioration trend of grassland was intensified; both grass quantity and quality declined. With overgrazing, proportions of inferior grass, weeds and poisonous weeds increased in plateau pastoral areas. Returning farmland to grazing, returning grazing to grassland, fence enclosure and artificial grassland construction have been implemented to restore the grassland vegetation, to increase the grassland coverage, to reasonably control the livestock carrying capacity, to prevent overgrazing, to keep balance between grassland and livestock, and to develop the ecological animal husbandry. In Northwest China, because the amount of regional water resources had an overall decreasing trend, there was a continuous expansion in the regional land desertification, and soil erosion was very serious. A series of measures, such as development of artificial precipitation (snow), water resources control, regional water diversion, water storage project and so on, were used effectively to respond to water deficit. It had played a certain role in controlling soil erosion by natural forest protection and returning farmland to forest and grassland. In the early 21st century, noticeable achievements had been made in prevention and control of desertification in Northwest China. The regional ecological environment has been improved obviously, and the desertification trend

  12. Dating of coal fires in Xinjiang, north-west China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.M.; Kroonenberg, S.B.; de Boer, C.B. [University of Utrecht, Utrecht (Netherlands). Faculty of Earth Science

    2004-04-01

    Coal fires in China consume vast amounts of fuel and cause serious environmental problems. Most of these coal fires are related to mining activity. However, naturally produced palaeo coal fires in Xinjiang, north-west China, have been recognized via burnt rocks. The burnt rocks in the study area are found at different river terraces underlying unburnt alluvial and river terrace deposits. Several age groups of coal fires have been identified based on the positions of burnt rocks at river terraces and the relationship between the burnt rocks and the terrace deposits. These palaeo coal fires are: (1) Pliocene - Early Quaternary in age at 200 m above present river terrace deposits; (2) Middle Pleistocene in age, at {gt} 90 m; (3) Late Pleistocene, at 90-70 m; (4) Holocene; (5) burnt rocks relating to active coal fires. Palaeomagnetic data of the burnt rocks from different terraces give normal remanent magnetization and help further to constrain the ages of the coal fires.

  13. Characteristics and geological significance of the late Triassic Carnian oolitic limestone in Hanwang area, northwest Sichuan Basin,China%川西北汉旺地区卡尼期鲕粒灰岩特征及地质意义

    Institute of Scientific and Technical Information of China (English)

    姬国锋; 范鸿; 时志强; 杜怡星

    2016-01-01

    Sedimentary facies,paleoclimate and paleosalinity of late Triassic Carnian oolitic limestone in the lower part of Ma'antang Formation,northwest Sichuan Basin are studied based on former achievements,field investigation and sedimentary facies analysis.The Carnian limestone section is composed of three parts,occurred as composite oolite,concentric oolite,radial-concentric oolite and brain-like oolite from the bottom to top,and they are mainly deposited on carbonate ramps under the condition of decreased seawater energy and deep sea water.However,the coexistence of brain-like oolite and concentric oolite on the top of the limestone and the bimodal size distribution of concentric oolite reveal that the formation of oolites is affected storm during the deposition.According to the analysis ofδ18 O andδ13 C,the paleotemperature is 24 ~35℃ and the Z value is 127 ~131 during the deposition of oolitic limestone.It implies that the northwest Sichuan Basin was an area with high evaporation and low latitudes and characterized by hot dry climates in early Carnian of the late Triassic.Oolitic limestone in the area is of great importance in the analysis and reconstruction of paleogeography and paleotemperature.%探讨川西北地区晚三叠世卡尼期马鞍塘组下部的鲕粒灰岩的沉积相及沉积时的古气候、古盐度。在前人研究成果基础上,对绵竹县汉旺观音崖剖面开展野外调查和室内薄片鉴定及碳氧同位素测试,结果表明共发育3套鲕粒灰岩,主要沉积于碳酸盐缓坡,由下到上鲕粒以复鲕、同心鲕、放射同心鲕、脑状鲕呈现,展示鲕粒沉积时海水能量降低、水体逐渐加深的趋势;上部灰岩中脑状鲕与同心鲕共存且同心鲕具双峰态粒度分布,显示鲕粒沉积时受到风暴作用影响。碳、氧同位素测试显示,鲕粒灰岩沉积时的古温度大体在24~35℃,Z 值在127~131,表明在卡尼期早期,川西北地区以蒸发量较高

  14. Maturation history modeling of Sufyan Depression, northwest Muglad Basin, Sudan

    Science.gov (United States)

    Wang, Ying; Liu, Luofu; An, Fuli; Wang, Hongmei; Pang, Xiongqi

    2016-08-01

    The Sufyan Depression is located in the northwest of Muglad Basin and is considered as a favorable exploration area by both previous studies and present oil shows. In this study, 16 wells are used or referred, the burial history model was built with new seismic, logging and well data, and the thermal maturity (Ro, %) of proved AG source rocks was predicted based on heat flow calculation and EASY %Ro modeling. The results show that the present heat flow range is 36 mW/m2∼50 mW/m2 (average 39 mW/m2) in 13 wells and 15 mW/m2∼55 mW/m2 in the whole depression. Accordingly, the geothermal gradient is 20 °C/km∼26 °C/km and 12 °C/km∼30 °C/km, respectively. The paleo-heat flow has three peaks, namely AG-3 period, lower Bentiu period and Early Paleogene, with the value decreases from the first to the last, which is corresponding to the tectonic evolution history. Corresponding to the heat flow distribution feature, the AG source rocks become mature earlier and have higher present marurity in the south area. For AG-2_down and AG-3_up source rocks that are proved to be good-excellent, most of them are mature with Ro as 0.5%-1.1%. But they can only generate plentiful oil and gas to charge reservoirs in the middle and south areas where their Ro is within 0.7%-1.1%, which is consistent with the present oil shows. Besides, the oil shows from AG-2_down reservoir in the middle area of the Sufyan Depression are believed to be contributed by the underlying AG-3_up source rock or the source rocks in the south area.

  15. Seismic refraction studies in the San Juan Basin, Northwest New Mexico

    Science.gov (United States)

    Evans, D.H.; Jaksha, L.H.

    1984-01-01

    The U.S. Geological Survey is studying some of the features of the earth's crust in the San Juan Basin region, northwest New Mexico. As a part of this study seismic refraction-reflection measurements were made in and around the basin using explosions and earthquakes as energy sources. Record sections and traveltime tables were derived from the measurements.

  16. Recent and Future Climate Change in Northwest China

    International Nuclear Information System (INIS)

    As a consequence of global warming and an enhanced water cycle, the climate changed in northwest China, most notably in the Xinjiang area in the year 1987. Precipitation, glacial melt water and river runoff and air temperature increased continuously during the last decades, as did also the water level of inland lakes and the frequency of flood disasters. As a result, the vegetation cover is improved, number of days with sand-dust storms reduced. From the end of the 19th century to the 1970s, the climate was warm and dry, and then changed to warm and wet. The effects on northwest China can be classified into three classes by using the relation between precipitation and evaporation increase. If precipitation increases more than evaporation, runoff increases and lake water levels rise. We identify regions with: (1) notable change, (2) slight change and (3) no change. The future climate for doubled CO2 concentration is simulated in a nested approach with the regional climate model-RegCM2. The annual temperature will increase by 2.7C and annual precipitation by 25%. The cooling effect of aerosols and natural factors will reduce this increase to 2.0C and 19% of precipitation. As a consequence, annual runoff may increase by more than 10%

  17. Seismic stratigraphy of the Qiongdongnan deep sea channel system, northwest South China Sea

    Institute of Scientific and Technical Information of China (English)

    YUAN Shengqiang; L(U) Fuliang; WU Shiguo; YAO Genshun; MA Yubo; FU Yanhui

    2009-01-01

    Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised channel which extends from the east boundary of the Yinggehai Basin, through the whole Qiongdongnan and the Xisha trough, and terminates in the western part of the northwest subbasin of South China Sea. It is more than 570 km long and 4-8 km wide. The chaotic (or continuous) middle (or high) amplitude, middle (or high) continuity seismic facies of the channel reflect the different lithological distribution of the channel. The channel formed as a complex result of global sea level drop during early Piiocene, large scale of sediment supply to the Yinggehai Basin, inversion event of the Red River strike-slip fault, and tilted direction of the Qiongdongnan Basin. The large scale of sediment supply from Red River caused the shelf break of the Yinggehai Basin to move torwards the S and SE direction and developed large scale of prograding wedge from the Miocene, and the inversion of the Red River strike-slip fault induced the sediment slump which formed the Qiongdongnan deep sea channel.

  18. Effect of the 1950s large-scale migration for land reclamation on spring dust storms in Northwest China

    Science.gov (United States)

    Ta, Wanquan; Dong, Zhibao; Sanzhi, Caidan

    During the 1950s, China experienced large-scale human migration for the purposes of land reclamation, industrialization, and construction in Northwest China, with a peak of nearly 70 million migrants in 1959 during the Great Leap Forward period. These intense human activities were responsible for the 1950s' dust storms in Northwest China. Due to large-scale reclamations, the number of spring dust storm days did not show much relationship with the number of spring strong wind days in the Tarim Basin and the Hexi Corridor, but they did correlate with the increase in annual land reclamation areas, with correlation coefficients of 0.82 and 0.88, respectively, in the two regions. Indeed, severe dust storm outbreaks (visibility less than 200 m) in Xinjiang, Gansu and Qinghai provinces in Northwest China were also found to be positively correlated with the number of annual immigrants and the annual increase in cultivated land areas in the period 1953-1968, with coefficients of 0.62 and 0.65, respectively.

  19. Assessment of undiscovered conventional oil and gas resources of Bonaparte Basin, Browse Basin, Northwest Shelf, and Gippsland Basin Provinces, Australia, 2011

    Science.gov (United States)

    Pollastro, Richard M.; Brownfield, Michael E.; Charpentier, Ronald R.; Cook, Troy A.; Klett, Timothy R.; Kirschbaum, Mark A.; Pitman, Janet K.; Schenk, Christopher J.

    2012-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 4.7 billion barrels of undiscovered oil and 227 trillion cubic feet of undiscovered natural gas in three major offshore petroleum basins of northwest Australia and in the Gippsland Basin of southeast Australia.

  20. 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.

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

    OpenAIRE

    Xiaomei Jin; Renhong Guo; Wei Xia

    2013-01-01

    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 algorit...

  2. 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

      Seismic stratigraphic and structural analyses of the northwest Phu Khanh Basin, offshore Central Vietnam, based on 2-D seismic data, indicate that the initial rifting began during the latest Cretaceous? or Palaeogene controlled by left-lateral transtension along the East Vietnam Boundary Fault ...

  3. Clinical characteristics of patients with gastroesophageal reflux disease in several centers of Northwest China

    Institute of Scientific and Technical Information of China (English)

    高麦仓

    2013-01-01

    Objective To investigate the clinical characteristics of gastroesophageal reflux disease (GERD) in several endoscopy centers of Northwest China.Methods From September 2008 to September 2009,a questionnaire survey was carried out in the endoscopy centers of four hospitals

  4. Prevalence and Determinants of Metabolic Syndrome among Adults in a Rural Area of Northwest China

    OpenAIRE

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

    2014-01-01

    Objectives To evaluate the prevalence and determinants of metabolic syndrome (MetS) among adults in a rural area of Northwest China. Methods 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 Edu...

  5. The Association of Maternal Lifestyle with Birth Defects in Shaanxi Province, Northwest China

    OpenAIRE

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

    2015-01-01

    Background The main objective was to investigate the burden of birth defects among alive infants and explore the impact of maternal lifestyle during pregnancy on the burden of birth defects in Northwest China. Methods A stratified multi-stage sampling method was used to study infants born during 2010–2013 (and their mothers) in Shaanxi province of Northwest China. Socio-demographic information was collected using a structured questionnaire, and medical records from the local hospitals were us...

  6. 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.

  7. [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. PMID:26995926

  8. Petroleum Exploration of Craton Basins in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Craton basins are a significant petroliferous provenance. Having undergone multiple openclose tectonic cycles and strong reworking of the late Cenozoic tectonic movement, the craton basins in China are highly broken. This has resulted in multi-source and multiphase hydrocarbon generation and later hydrocarbon accumulation so that a complicated spatial assemblage of primary, paraprimary and secondary oil-gas pools has been formed. The primary factors controlling hydrocarbon accumulation include hydrocarbon-generating depressions, paleouplifts, paleoslopes, unconformity surfaces, paleo-karst, faults and fissure systems as well as the later conservation conditions. In consequence, the strategy of exploration for China's craton basins is to identify the effective source rocks, pay attention to the different effects of paleohighs and late reworking, enhance studies of the secondary storage space, attach importance to the exploration of lithologic oil-gas reservoirs and natural gas pools, and approach consciously from the secondary oil pools to the targets near the source rocks. At the same time, a complete system of technologies and techniques must be built up.

  9. Petroleum Exploration Prospects in Erlian Basin,China

    Institute of Scientific and Technical Information of China (English)

    Fei Baosheng

    1994-01-01

    @@ Erlian Basin is located in the middle prairie,Inner Mongolia Autonomous Region, the north border of China. Teetonieally, Erlian Basin is to the south of Bayinbaoligel Uplift and the north is the Wendouer Temple Uplift. In the east of the basin, there is Daxinganling Uplift and the west is Soulunshan Uplift. The basin covered an area of 100 000 km2, is a Mesozoic Cenozoic graben (rift)basin that evolved on the folded basement of Heveynian geosyncline.

  10. 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

  11. 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.

  12. Tectonic affinity of the Alxa Block, Northwest China: Constrained by detrital zircon U-Pb ages from the early Paleozoic strata on its southern and eastern margins

    Science.gov (United States)

    Zhang, Beihang; Zhang, Jin; Zhang, Yiping; Zhao, Heng; Wang, Yannan; Nie, Fengjun

    2016-06-01

    The tectonic affinity of the Alxa Block is important in the reconstruction of the paleogeographical evolution of China. The early Paleozoic strata (the Dahuangshan Formation and Xiangshan Group) of the southern and eastern Alxa Block have consistent rock compositions, similar depositional ages, paleocurrents, detrital zircon age distributions, and cumulative probability curves of crystallization ages for detrital zircon grains relative to the depositional ages, and were deposited in similar slope basins. All these data indicate that the early Paleozoic strata of the Alxa Block were sourced predominantly from Neoproterozoic orogenic belts in the eastern Gondwana continent, instead of the Alxa Block to the north, the North China Block to the east and the North Qilian Orogenic Belt to the south. During the early Paleozoic, the Alxa Block was an independent block with the South China Block (SCB) to the west and the North China Block (NCB) to the east and situated to the northwest of the eastern Gondwana with its long axis trending north northwest-south southeast, and it belonged to a passive continental margin dipping to the north northwest, with the eastern part of the margin located closer to the eastern Gondwana. The Hexi Corridor is part of the Alxa Block and a part of the same slope basin during the early Paleozoic. The southern boundary of the Alxa Block is now the front thrust of the North Qilian Shan.

  13. The Geochemical Characteristics of Coals from the Junggar Basin in Northwest China and the Relation of the Configuration of Pristane with Maturity in Highly Mature and Over-Mature Samples

    Directory of Open Access Journals (Sweden)

    Wu Yingqin

    2016-05-01

    Full Text Available Coal samples analyzed from Junggar Basin are characterized by high Total Organic Carbon (TOC contents (63.7-82.2% in all samples, except the highly over-mature samples Ha-01 and Ha-02, and high S2 (60.5-83.0 mg HC/g rock and Hydrogen Index (HI values (77-118 mg HC/g TOC, indicating the coal rocks have excellent source rock potential. The Tmax values (418-531°C, C29 sterane 20S/(20S+20R ratios (0.20-0.54 and C31 homohopane 22S/(22S+22R ratios (0.26-0.61 indicate an immature to highly over-mature stage of organic matter, which is supported by the organic geochemical maturation parameters. In addition, n-alkane carbon numbers range from C11 to C33 with maxima at n-C19 or n-C23, exhibiting unimodal distribution patterns except Ai-13 and Ha-01, and low Pr/Ph ratios (0.29-0.80 in Ai-01, Ai-13, Ha-01 and Ha-02, indicating a suboxic reductive environment. In Wu-8, Wei-09 and Shinan-20, the Pr/Ph ratios are clearly greater than 1.0 (2.43-3.23, indicating oxic depositional conditions. Furthermore, pristane isomers were identified in extracts from these coal samples. Using coals of different maturity, which correspond to vitrinite reflectances (%Ro of 0.36-2.99%, the Pristane Isomerization Ratio (PIR (PIR = [6(R10(R+6(S10(S]/6(R10(S ranges from 0.42 to 0.97 for the coal extracts. The value of the PIR, which is a molecular maturity parameter, is evaluated by analyzing a series of samples using known values of the molecular maturity parameter based on the sterane and hopane isomerization indices, and the Methyl Phenanthrene Index (MPI. Changes to the PIR in highly mature Ai-13 (Ro > 1.5% and over-mature Ha-01 and Ha-02 (Ro > 2.0% are clear; thus, a linear correlation is evident between the PIR and Ro. The results suggest that the PIR is an appropriate indicator of maturity for the highly mature and over-mature coal samples in the Junggar Basin.

  14. 酒西盆地青西坳陷下白垩统油气生成的地质控制因素%Geological Constraints on Petroleum Generation in the Qingxi Depression (Lower Cretaceous), Jiuxi Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    王琪; 史基安; 陈国俊; 杨智明

    2005-01-01

    The Qingxi Depression, over an area of merely 490 km2, is a petroliferous depositional center within the Jiuxi Basin. Lower Cretaceous source rocks in this depression are a suite of mudstones, dolomitic mudstones and argillaceous dolostones formed in a deep lacustrine environment. Although their distribution area is small, their thickness is sizable.High abundance and favorable types of organic matter provide an important material basis for petroleum generation. The majority of the source rocks in the Qingxi Depression are of maturation conditions for generating significant volumes of petroleum, and with only one peak generation period that commenced in the Neogene. The Himalayan movement results in a northerly overthrusting of the Qilian Mountains nappe to form a series of compressional faults, shear faults and rock fractures, all of which serve as main conduits for petroleum migration from west to east, and, in addition, as the reservoir space of the Qingxi Oilfield. Based on these factors, it is suggested that the future exploration be on the Qingxi low bulge and favorable fracturing zone within this depression.

  15. Tectonostratigraphic history of the Ediacaran-Silurian Nanhua foreland basin in South China

    Science.gov (United States)

    Yao, Wei-Hua; Li, Zheng-Xiang

    2016-04-01

    This paper presents the tectonostratigraphic evolution of the Ediacaran-Silurian Nanhua Basin in South China and explores the relationship between clastic sedimentation in the basin and evolution of the adjacent Wuyi-Yunkai orogen. Sedimentary facies in the basin comprises, in an ascending order, turbiditic marine, shallow marine, and fluvial-dominated deltaic facies, featuring a lateral migration from southeast to northwest. We interpret the Ediacaran-Silurian Nanhua Basin as a foreland basin with a three-stage evolution history. Stage 1: the Ediacaran-Cambrian stage, recording the start of tectonic subsidence with turbiditic marine siliciclastic deposition, fed by exotic orogens outboard South China; Stage 2: the Ordovician to earliest-Silurian stage, characterized by a migrating depocenter with dominant shallow marine and deltaic siliciclastic deposition, fed by the local and northwestward propagating Wuyi-Yunkai orogen; Stage 3: the Silurian stage, showing the arrival of depocenter in the Yangtze Block during the waning stage of the orogeny with deltaic deposition in the remanent foreland basin. The Wuyi-Yunkai orogen remained the dominant sedimentary source region during Stage 3. Stage 1 was likely related to the collision of the South China Block toward northern India during the assembly of Gondwana, whereas Stages 2 and 3 recorded sedimentation during the northwestward propagation and subsequent orogenic root delamination/collapse of the Wuyi-Yunkai orogen, respectively. The Wuyi-Yunkai orogeny in South China is interpreted to have resulted from the far-field stress of the collision between South China and Indian Gondwana.

  16. EVAPOTRANSPIRATION OF LOW-LYING PRAIRIE WETLAND IN MIDDLE REACHES OF HEIHE RIVER IN NORTHWEST CHINA

    Institute of Scientific and Technical Information of China (English)

    WU Jin-kui; DING Yong-jian; WANG Gen-xu; SHEN Yong-ping; Yusuke YAMAZAKI; Jumpei KUBOTA

    2005-01-01

    Low-lying prairie wetland, which has characteristics of both grassland and wetland, has irreplaceable ecological fmctions in inland river basins of Northwest China. Owing to its small-scale distribution, so far, the observation and research on it are rare. The estimation ofevapotranspiration is significant to ecological and environmental construction, scientific management of pasture and protection of wetland. For studying the evapotranspiration (ET) of low-lying prairie wetland in the middle reaches of the Heihe River, an inland river, in Northwest China, the automatic weather station in Linze Ecological Experimental Station of Lanzhou University (39°15'3"N, 100°03' 52"E), Linze, Gansu Province,was selected as a case study. Based on meteorological data collected, Bowen-Ratio Energy Balance (BREB) method was used to calculate the evapotranspiration (ET) of low-lying prairie wetland. The analysis results showed that in a whole year (September 2003 -August 2004), the total ET was 611.5mm and mean daily 1.67mm/d. The ET varied with different growing stages. In non-growing stage (NGS), initial growing stage (IGS), middle growing stage (MGS) and end growing stage (EGS), the ET was 0.57, 2.01, 3.82 and 1.49mm/d, with a percentage of total ET of 18.26%, 9.20%, 61.83% and 10.71% respectively. In March, ET began to increase. But in April, the ET increased most. After that, it increased gradually and got the maximal value in July. From then on, the ET decreased gradually. In September, the ET decreased rapidly. With the ending of growing and the freezing of soil, the ET stopped from the middle of November to February in next year. Hourly ET analysis showed that at 8:00 a.m. (during MGS at 7:00 a.m.), the evapotranspiration began, at 13:00 p.m.got its maximal value and at 19:00 p.m. (during MGS at 20:00 p.m.), the evapotranspiration stopped. The intensity of ET in sunny day was much larger than that in cloudy day in the same growing stage.

  17. Spatiotemporal variations of soil moisture in the Tarim River basin, China

    Science.gov (United States)

    Su, Buda; Wang, Anqian; Wang, Guojie; Wang, Yanjun; Jiang, Tong

    2016-06-01

    Based on in situ soil moisture and river runoff records in the Tarim River basin, usability of the long term Essential Climate Variable (ECV) soil moisture dataset is validated in the arid climatic region of China. The spatio-temporal variation of soil moisture and its possible influencing factors in the 1988-2013 is also preliminary analyzed in the current paper. Results reveal that the ECV soil moisture can capture the large scale dynamics of regional water cycle quite satisfactorily, showing good agreement with in situ observations in their seasonal and interannual variability. In the period of 1988-2013, the ECV soil moisture shows obvious increasing trends in the northwest and the southwest parts of the Tarim River basin, particularly in spring (March-May) and autumn (September-November). Statistical analysis further suggests that the variations of soil moisture in the Tarim River basin are more controlled by precipitation, and temperature is less effective in controlling of soil moisture variations.

  18. Source of atmospheric moisture and precipitation over China's major river basins

    Science.gov (United States)

    Zhao, Tongtiegang; Zhao, Jianshi; Hu, Hongchang; Ni, Guangheng

    2016-03-01

    Oceanic evaporation via the East Asian Monsoon (EAM) has been regarded as the major source of precipitation over China, but a recent study estimated that terrestrial evaporation might contribute up to 80% of the precipitation in the country. To explain the contradiction, this study presents a comprehensive analysis of the contribution of oceanic and terrestrial evaporation to atmospheric moisture and precipitation in China's major river basins. The results show that from 1980 to 2010, the mean annual atmospheric moisture (precipitable water) over China was 13.7 mm, 39% of which originates from oceanic evaporation and 61% from terrestrial evaporation. The mean annual precipitation was 737 mm, 43% of which originates from oceanic evaporation and 57% from terrestrial evaporation. Oceanic evaporation makes a greater contribution to atmospheric moisture and precipitation in the East Asian Monsoon Region in South and East China than terrestrial evaporation does. Particularly, for the Pearl River and southeastern rivers, oceanic evaporation contributes approximately 65% of annual precipitation and more than 70% of summer precipitation. Meanwhile, terrestrial evaporation contributes more precipitation in northwest China due to the westerly wind. For the northwestern rivers, terrestrial evaporation from the Eurasian continents contributes more than 70% of precipitation. There is a linear relation between mean annual precipitation and the contribution of oceanic evaporation to precipitation, with a correlation coefficient of 0.92, among the ten major river basins in China.

  19. Source of atmospheric moisture and precipitation over China's major river basins

    Institute of Scientific and Technical Information of China (English)

    Tongtiegang ZHAO; Jianshi ZHAO; Hongchang HU; Guangheng NI

    2016-01-01

    Oceanic evaporation via the East Asian Monsoon (EAM) has been regarded as the major source of precipitation over China,but a recent study estimated that terrestrial evaporation might contribute up to 80% of the precipitation in the country.To explain the contradiction,this study presents a comprehensive analysis of the contribution of oceanic and terrestrial evaporation to atmospheric moisture and precipitation in China's major river basins.The results show that from 1980 to 2010,the mean annual atmospheric moisture (precipitable water) over China was 13.7 mm,39% of which originates from oceanic evaporation and 61% from terrestrial evaporation.The mean annual precipitation was 737 mm,43% of which originates from oceanic evaporation and 57% from terrestrial evaporation.Oceanic evaporation makes a greater contribution to atmospheric moisture and precipitation in the East Asian Monsoon Region in South and East China than terrestrial evaporation does.Particularly,for the Pearl River and southeastern rivers,oceanic evaporation contributes approximately 65% of annual precipitation and more than 70% of summer precipitation.Meanwhile,terrestrial evaporation contributes more precipitation in northwest China due to the westerly wind.For the northwestern rivers,terrestrial evaporation from the Eurasian continents contributes more than 70% of precipitation.There is a linear relation between mean annual precipitation and the contribution of oceanic evaporation to precipitation,with a correlation coefficient of 0.92,among the ten major river basins in China.

  20. Why does precipitation in northwest China show a significant increasing trend from 1960 to 2010?

    Science.gov (United States)

    Li, Baofu; Chen, Yaning; Chen, Zhongsheng; Xiong, Heigang; Lian, Lishu

    2016-01-01

    Based on monthly precipitation data from 74 weather stations in the arid region of northwest China, we employed statistical methods to analyse the characteristics of precipitation and investigated the relationships between precipitation and 11 atmospheric circulations. The results showed that the precipitation in northwest China had a significantly increasing trend (P China (- 0.16 mm/year) for the same period. Annual precipitation increased markedly after 1987, but the increase in precipitation gradually declined from north to south and from west to east. We found that the precipitation variation in spring, summer, autumn, and winter plays an important role in the yearly change, accounting for 21.6%, 42.4%, 18.4%, and 17.6%, respectively. The correlation analysis indicated that the annual precipitation revealed strong and significant associations with the West Pacific Subtropical High (WPSH, R = 0.60, P China.

  1. Northwest disposal site for LLW and ILW in China radioactive impact assessment

    International Nuclear Information System (INIS)

    This paper describes the studies and main conclusions in site selection, design, and radioactive impact assessment of the Northwest Disposal Site of China for intermediate- and low-level radioactive wastes. At the end of the paper, further works are proposed

  2. Study on the glacier variation and its runoff responses in the arid region of Northwest China

    Institute of Scientific and Technical Information of China (English)

    刘潮海; 康尔泗; 刘时银; 陈建明; 刘宗香

    1999-01-01

    The glaciers in the arid region of Northwest China are viewed as an independent system, and glacier variation and mass balance fluctuation since the Little Ice Age and in the recent decades are estimated. Based on the estimation, the threshold time of glacier runoff against the backgrounds of the current and future varying climate conditions is simulated.

  3. Tectonic Evolution of China and Its Control over Oil Basins

    Institute of Scientific and Technical Information of China (English)

    Wang Hongzhen; Li Sitian

    2004-01-01

    This paper is a brief review of the tectonic frame and crustal evolution of China and their control over the oil basins. China is subdivided into three regions by the Hercynian Ertix-Almantai (EACZ) and Hegenshan (HGCZ) convergent zones in the north, and the Indosinian Muztagh-Maqen (MMCZ) and the Fengxiang-Shucheng (FSCZ) convergent zones in the south. The northern region represents the southern marginal tract of the Siberian platform. The middle region comprises the Sino-Korea (SKP), Tarim (TAP) platforms and surrounding Paleozoic orogenic belts. The southern region includes the Yangtze platform (YZP), the Cathaysia (CTA) paleocontinent and the Caledonides between them in the eastern part, and the Qinghai-Tibet plateau composed of the Gondwana-affiliated massifs and Meso- and Cenozoic orogenic belts in the western part. The tectonic evolutions of China are described in three stages: Jinningian and pre-Jinningian, Caledonian to Indosinian, and post-Indosinian. Profound changes occurred at the end of Jinningian (ca. 830 Ma) and the Indosinian (ca. 210 Ma) tectonic epochs, which had exerted important influence on the formation of different types of basins. The oil basins distribute in four belts in China, the large superimposed basins ranging from Paleozoic to Cenozoic (Tarim and Junggar) in the western belt, the large superimposed basins ranging from Paleozoic to Mesozoic (Ordos and Sichuan) in the central belt, the extensional rift basins including the Cretaceous rift basins (Songliao) and the Cenozoic basin (Bohaiwan) in the eastern belt, and the Cenozoic marginal basins in the easternmost belt in offshore region. The tectonic control over the oil basins consists mainly in three aspects: the nature of the basin basement, the coupling processes of basin and orogen due to the plates interaction, and the mantle dynamics, notably the mantle upwelling resulting in crustal and lithospheric thinning beneath the oil basins.

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

    International Nuclear Information System (INIS)

    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

  5. Mesozoic basins and associated palaeogeographic evolution in North China

    Institute of Scientific and Technical Information of China (English)

    Yong-Qing Liu; Hong-Wei Kuang; Nan Peng; Huan Xu; Peng Zhang; Neng-Sheng Wang; Wei An

    2015-01-01

    In North China, the Mesozoic terrestrial basins, sedimentary palaeogeography and tectonic settings involved ifve evolutionary stages:(1) the Early-Middle Triassic, (2) the Late Triassic to Early-Middle Jurassic, (3) the Late Jurassic to early Early Cretaceous, (4) the middle-late Early Cretaceous and (5) the Late Cretaceous. The regional punctuated tectonic events occurred during these evolutionary stages. During the Early-Middle Triassic (stage 1), the Xingmeng Orogenic Belt (XMOB, i.e., east-ern part of Central Asia Orogenic Belt, CAOB) of the northern North China was settled in the transition of tectonic environment from syn-orogenic compression to post-orogenic extension with intensive uplifting. It is a main provenance in the uniifed Ordos-North China Basin.The united continental plate of China and the Qinling-Dabie-Sulu Orogenic Belt formed due to convergence and collision between the North China Plate and the Yangtze Plate along two suture zones of the Mianlue and the Shangdan in the terminal Middle Triassic. During the Late Triassic to the Early-Middle Jurassic (stage 2), the Late Triassic maifc or alkaline rocks and intrusions occurred on the northern and southern margins of North China Craton (NCC) and XMOB, implying that intensiifed extension happened all over the North China (early phase of stage 2). Additionally, in the late phase of stage 2, the basic volcanic-iflling faulted basins were widely distributed in the northeastern North China during the Early-Middle Jurassic, including a series of small-to medium-sized basins with coal-bearing strata and some volcanic rocks in other areas of North China, which was the result of subduction of the Palaeo-Paciifc Plate during the Early-Middle Jurassic. An active continental margin with accretionary complex developed in the eastern Heilongjiang of China, Japan and the Far East of Russia at that time. However, in the end of the Early-Middle Jurassic, because of the Yan-shanian orogeny characterized by

  6. 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. PMID:26544070

  7. Dynamic changes of sandy land in northwest of Beijing, China.

    Science.gov (United States)

    Wang, Jing; He, Ting; Guo, Xudong; Liu, Aixia; Zhou, Qing

    2006-10-01

    The area northwest of Beijing is one of the most important regions where many organizations invest and pay most attention. The environmental problems in this region affect not only Beijing but also the surrounding area. Based on observation of the characteristics of the change in sandy land, this study classified four types of dynamic change of sandy land, including extended sandy land, the reversely changed sandy land, the potential sandy land and no change in sandy land. Then the process and the trend of changes in sandy land and their environmental impact on the area northwest of Beijing were analyzed. The results show that the area of sandy land has increased in this region in the period of 1991 to 2002. Change between sandy land and grassland was the dominant change. It is found that the monitoring zones of Hunshandake sandy land and north of Yin Shan are regions with high ratio of extended sandy land, and are connected with widespread potential change of sandy land. This implies that these two regions have a high probability of increase in sandy land in the future. On the other hand, in the monitoring zone of Horqin sandy land and Ba Shang Plateau and its surrounding area, desertification had been controlled and the area of sandy land is expected to decrease. This indicates that the direction of the sandstorm to Beijing is expected to gradually move to the northwest. Furthermore, the decreases in sandy land and the reversing change from arable land to grassland and forests in the study region will affect the land quality and atmosphere. And the logistic multiple regression (LMR) model was employed to better understand the complexity and processes of increases in sandy land. This model predicts that there is a high probability of increases in sandy land in north of Siziwang Banner, Zhengxiangbai Banner and Zhenglan Banner. Finally, suggestions to the ecological construction of the study area have been proposed. PMID:16758285

  8. Post-generative alteration effects on petroleum in the onshore Northwest Java Basin, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Napitupulu, Haposan [Pertamina EP, Jakarta (Indonesia); Texas University at Dallas, Richardson, TX (United States); Ellis, Leroy [ARCO Exploraton and Production Technology, Plano, TX (United States); Terra Nova Technologies, Dallas, TX (United States); Mitterer, R.M. [Texas University at Dallas, Richardson, TX (United States)

    2000-07-01

    Northwest Java Basin oils, largely derived from the fluvial-deltaic to nearshore marine Talangakar formation of Oligocene to Early Miocene, range from heavy oils to extremely light oils and retrograde condensates, with API gravities of a suite of oils ranging from about 17{sup o} to 53{sup o}. Heavy oils, with API gravities less than 22{sup o}, all of which are in shallow reservoirs, are biodegraded. Pristine oils concomitant with related derivative residual and retrograde condensate oil types indicate evaporative fractionation phenomena. Post-generative alteration processes are widespread in this highly faulted region. Pristane to phytane biomarker ratios of retrograde condensates and residual oils have been shown to be severely affected by evaporative fractionation. Principal component analysis (PCA) of isotope and biomarker data identified two oil families associated with source rocks of the Talangakar formation. One group is suggested to be derived from more marine influenced delta-front to prodelta depositional settings, while the second group is attributed to a higher plant-rich delta-plain to delta-front depositional environment. Correlation of these oil families with the varied depositional environments of the Talangakar formation has allowed a more refined approach to the identification of hydrocarbon migration pathways in the Northwest Java Basin. Multivariate statistical analysis is shown to be an effective tool in correlating high gravity condensate oil types. (Author)

  9. Detrital provenance of Early Mesozoic basins in the Jiangnan domain, South China: Paleogeographic and geodynamic implications

    Science.gov (United States)

    Xu, Xianbing; Tang, Shuai; Lin, Shoufa

    2016-04-01

    Detrital provenance analysis is an effective way to understand paleogeographic change and geodynamics. In this paper, we present petrological, whole-rock geochemical and detrital zircon U-Pb geochronological analysis of Early and Middle Jurassic terrestrial clastic rocks in the Jingdezhen Basin and the Huangshan Basin in the Jiangnan domain, South China. Petrology and whole-rock geochemistry show that the source rocks are dominated by intermediate to acid component. The Chemical Index of Alteration ranges from 69 to 86, suggesting a moderate weathering history for the source rocks. The Early-Middle Jurassic sediments in the Jingdezhen and Huangshan basins were mostly sourced from magmatogenic greywackes and felsic magmatic rocks, respectively. Detrital zircons have seven age peaks at ~ 240 Ma, ~ 430 Ma, ~ 1390 Ma, ~ 1880 Ma, ~ 2500 Ma, -3200 Ma and 788-999 Ma (a wide peak). Provenance analysis indicates that the source rocks are in the Jiangnan domain, the Northwest Zhejiang Basin and the Wuyishan domain. Combining these with previous results and paleocurrent directions, we infer that the NE-trending Wuyishan and Xuefengshan domains and the nearly E-W-Jiangnan domain and Nanling tectonic belt were orogenic uplifts and watersheds during the Late Triassic to Middle Jurassic. The Early Mesozoic geodynamics in the South China Block was related to the westward subduction of the Paleo-Pacific Plate and the northward continent-continent collision following the closure of the Paleo-Tethys Ocean.

  10. Resource integration of regional economic development in northwest China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Northwestern area is the most arid and underdeveloped area in China. Lots of researches have been done to find the approaches to alleviate poverty. But there are some problems, for example, how to invest, how to use capital,and why the utilization rate is ambiguous. Water, capital and human resources are analyzed in this paper to be compared with their Utilization rates. As a result, according to the dependences of economic growth on those resources, a new approach has been selected to organize the integration ways among these resources for economic development in northwestern China. The efficient ways to develop northwestern China are: firstly, use the wanting resources most effectively to make an efficient integration model of multiple resources. For example, enhance the utilization rate of water to raise the value of other resources. Secondly, invest more in basic factors for economic development to upgrade the competitiveness in the western China. For example, invest more in primary education and sustainable development of basic natural resources in order to have more power for sustainable development.

  11. 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…

  12. 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

  13. Conservation and restoration of degraded ecosystems in arid and semi-arid areas of northwest China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In "West Development" of China, one of the most important activities is the Natural Forest Protection Program, designed to swiftly convert the focus of management and utilization of the natural forests from a timber orientation towards forest conservation, sustainable management and environmental protection. The project covered almost all the arid and semi-arid regions in Northwest region. Accompanying this great campaign this paper studied the conservation and restoration model of degraded ecosystems in arid and semi-arid lands in Northwest China. The past practices have resulted in considerably natural forest degradation and loss through land conversion (primarily for agriculture), over-harvesting, inadequate reforestation and lack of protection. The consequences have been the loss of soil and water resources, diminished timber production capacity on a sustainable basis, and environmental losses. This paper applied Aronson's restoration model and proposed the conservation, restoration, re-allocation and preservation program for the implementation of environmental improvement and natural forest conservation.

  14. Classification of Complex Reservoirs in Superimposed Basins of Western China

    Institute of Scientific and Technical Information of China (English)

    PANG Xiongqi; ZHOU Xinyuan; LIN Changsong; HUO Zhipeng; LUO Xiaorong; PANG Hong

    2010-01-01

    Many of the sedimentary basins in western China were formed through the superposition and compounding of at least two previously developed sedimentary basins and in general they can be termed as complex superimposed basins.The distinct differences between these basins and monotype basins are their discontinuous stratigraphic sedimentation,stratigraphic structure and stratigraphic stress-strain action over geological history.Based on the correlation of chronological age on structural sections,superimposed basins can be divided into five types in this study:(1)continuous sedimentation type superimposed basins,(2)middle and late stratigraphic superimposed basins,(3)early and late stratigraphic superimposed basins,(4)early and middle stratigraphic superimposed basins,and(5)long-term exposed superimposed basins.Multiple source-reservoir-caprock assemblages have developed in such basins.In addition,multi-stage hydrocarbon generation and expulsion,multiple sources,polycyclic hydrocarbon accumulation and multiple-type hydrocarbon reservoirs adjustment,reformation and destruction have occurred in these basins.The complex reservoirs that have been discovered widely in the superimposed basins to date have remarkably different geologic features from primary reservoirs,and the root causes of this are folding,denudation and the fracture effect caused by multiphase tectonic events in the superimposed basins as well as associated seepage,diffusion,spilling,oxidation,degradation and cracking.Based on their genesis characteristics,complex reservoirs are divided into five categories:(1)primary reservoirs,(2)trap adjustment type reservoirs,(3)component variant reservoirs,(4)phase conversion type reservoirs and(5)scale-reformed reservoirs.

  15. 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...

  16. 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.

  17. Developing microfinance models to facilitate adoption of biogas systems in rural Northwest China

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Gabrielle [PlaNet Finance, Beijing (China)

    2011-07-01

    This paper discusses a successful means of increasing low-income populations' access to renewable energy technology. Actions included the tailoring of micro-credits to the needs of low-income investors in biogas, the development of systems to assure long-term and efficient use of the technology, and the integration of more comprehensive trainings which increase awareness on the system's requirements for year-long operations especially during the cold winters of Northwest China. (orig.)

  18. A Study of Internet Use in EFL Teaching and Learning in Northwest China

    OpenAIRE

    Chunqin Zhang

    2013-01-01

    Internet has been researched and employed as an educational tool by teachers and researchers in many countries in recent years. This paper explores Internet use in EFL teaching and learning in universities in Northwest China. A quantitive research was conducted among college teachers and students. The result indicates that both teachers and students are not well prepared for the use of Internet in EFL teaching and learning. Based on the result, this paper presents three suggests: developing a...

  19. The Influence of Land Surface Changes on Regional Climate in Northwest China

    Institute of Scientific and Technical Information of China (English)

    XU Xingkui; ZHANG Feng; Jason K.LEVY

    2007-01-01

    Land surface changes effect the regional climate due to the complex coupling of land-atmosphere interactions. From 1995 to 2000, a decrease in the vegetation density and an increase in ground-level thermodynamic activity has been documented by multiple data sources in Northwest China, including meteorological, reanalysis from European Centre for Medium-Range Weather Forecasts (ECMWF), National Oceanic and Atmospheric Administration's (NOAA) Advanced Very High Resolution Radiometer (AVHRR) and TIROS Operational Vertical Sounder (TOVS) satellite remote sensing data. As the ground-level thermodynamic activity increases, humid air from the surrounding regions converge toward desert (and semi-desert) regions, causing areas with high vegetation cover to become gradually more arid. Furthermore, land surface changes in Northwest China are responsible for a decrease in total cloud cover, a decline in the fraction of low and middle clouds, an increase in high cloud cover (due to thermodynamic activity) and other regional climatic adaptations. It is proposed that, beginning in 1995, these cloud cover changes contributed to a "greenhouse" effect, leading to the rapid air temperature increases and other regional climate impacts that have been observed over Northwest China.

  20. Temporal and spatial variability of drought in Huang-Huai-Hai River Basin, China

    Science.gov (United States)

    Yuan, Zhe; Yan, Deng-Hua; Yang, Zhi-Yong; Yin, Jun; Yuan, Yong

    2015-11-01

    Drought is a kind of extreme hydrological event. With the penetration of climate change impact, severity, areal extent, and frequency of drought are increasing, especially in Huang-Huai-Hai River Basin, which plays a key role in China's agriculture production. Analyzing the regional temporal and spatial variability in the context of climate change could provide a basis for the evasion of disasters and risk. The maximum number of consecutive dry days was selected as the indicator to analyze the decadal variability of drought severity, areal extent, and spatial variability of drought frequency in different seasons in Huang-Huai-Hai River Basin. Based on these, temporal and spatial variability of two kinds of special extreme events—consecutive drought and heavy rain after drought—were studied. The results showed that: (1) Huang-Huai-Hai River Basin mainly experienced moderate drought and severe drought. Moderate drought mainly occurs in autumn. High-frequency region of moderate drought is located in the plain of Huang-Huai-Hai River Basin, and its area is approximately 22.7 % of Huang-Huai-Hai River Basin. Severe drought often occurs in spring with high-frequency region in the upstream of the Yellow River. The area of this high-frequency region is about 6 % of Huang-Huai-Hai River Basin. (2) During 1961~2011, the areal extent of summer severe drought, autumn severe drought, and extreme drought all showed increasing trend, in which the increasing trend of the autumn severe drought area in the Yellow River has reached the significance level α = 0.05. (3) Consecutive drought of several seasons often took place in Ningxia plain and Hetao plain which lie in the northwest of the Yellow River Basin. In the recent 20 years, consecutive drought from spring to summer and consecutive drought from summer to autumn occurred frequently. Drought-flood abrupt alternation such as heavy rain after drought often occurred in summer temporally and Huaihe River Basin spatially.

  1. Tectonics and Sedimentary Basins of the South China Sea: Challenges and Progresses

    Institute of Scientific and Technical Information of China (English)

    Zhou Di; Yao Bochu

    2009-01-01

    @@ The special issue "Tectonics and Sedimentary Basins of the South China Sea" consists of 19 articles arranged in the order of deep structure,general tectonics,tectonic modeling,and sedimentary basins especially the deepwater sedimentary basins.

  2. Groundwater Systems and Resources in the Ordos Basin, China

    Institute of Scientific and Technical Information of China (English)

    HOU Guangcai; LIANG Yongping; SU Xiaosi; ZHAO Zhenghong; TAO Zhengping; YIN Lihe; YANG Yuncheng; WANG Xiaoyong

    2008-01-01

    The Ordos Basin is.a large-scalesedimentary basin in northwestern China. The hydrostratigraphic units from bottom to top are pre-Cambrian metamorphic rocks, Lower Paleozoic carbonate rocks, Upper Paleozoic to Mesozoic clastic rocks and Cenozoic deposits. The total thickness is up to 6000 m. Three groundwater systems are present in the Ordos Basin, based on the geological settings, I.e. The karst groundwater system, the Cretaceous dastic groundwater system and the Quaternary groundwater system. This paper describes systematically the groundwater flow patterns of each system and overall assessment of groundwater resources.

  3. 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 ( PChina.

  4. Mesozoic basin evolution and tectonic mechanism in Yanshan, China

    Institute of Scientific and Technical Information of China (English)

    LIU; Shaofeng; LI; Zhong; ZHANG; Jinfang

    2004-01-01

    The Mesozoic basins in Yanshan, China underwent several important tectonic transformations, including changes from a pre-Late Triassic marginal cratonic basin to a Late Triassic-Late Jurassic flexural basin and then to a late Late Jurassic-Early Cretaceous rift basin. In response to two violent intraplate deformation at Late Triassic and Late Jurassic, coarse fluvial depositional systems in Xingshikou and Tuchengzi Formations were deposited in front of thrust belts. Controlled by transform and extension faulting, fan deltas and lacustrine systems were deposited in Early Cretaceous basins. The composition of clastic debris in Late Triassic and Late Jurassic flexural basins respectively represents unroofing processes from Proterozoic to Archean and from early deposited, overlying pyroclastic rocks to basement rocks in provenance areas. Restored protobasins were gradually migrated toward nearly NEE to EW-trending from Early Jurassic to early Late Jurassic. The Early Cretaceous basins with a NNE-trending crossed over early-formed basins. The Early-Late Jurassic and Early Cretaceous basins were respectively controlled by different tectonic mechanisms.

  5. Minimal groundwater leakage restricts salinity in a hydrologically terminal basin of northwest Australia

    Science.gov (United States)

    Skrzypek, Grzegorz; Dogramaci, Shawan; Rouillard, Alexandra; Grierson, Pauline

    2016-04-01

    The Fortescue Marsh (FM) is one of the largest wetlands of arid northwest Australia (~1200 km2) and is thought to act as a terminal basin for the Upper Fortescue River catchment. Unlike the playa lake systems that predominate in most arid regions, where salinity is driven by inflow and evaporation of groundwater, the hydrological regime of the FM is driven by inundation from irregular cyclonic events [1]. Surface water of the FM is fresh to brackish and the salinity of the deepest groundwater (80 m b.g.l.) does not exceed 160 g/L; salt efflorescences are rarely present on the surface [2]. In this study, we tested the hypothesis that persistent but low rates of groundwater outflow have restricted the accumulation of salt in the FM over time. Using hydrological, hydrochemical data and dimensionless time evaporation modelling along with the water and salt budget, we calculated the time and the annual groundwater discharge volume that would be required to achieve and maintain the range of salinity levels observed in the Marsh. Groundwater outflow from alluvial and colluvial aquifers to the Lower Fortescue catchment is limited by an extremely low hydraulic gradient of 0.001 and is restricted to a relatively small 'alluvial window' of 0.35 km2 because of the elevation of the basement bedrock at the Marsh outflow. We show that if the Marsh was 100% "leakage free" i.e., a true terminal basin for the Upper Fortescue Catchment, the basin water would have achieved salt saturation after ~45 ka. This is not the case and only a very small outflow of saline groundwater of GL/yr (<0.03% of the FM water volume) is needed to maintain the current salinity conditions. The minimum time required to develop the current hydrochemical composition of the water in the Marsh and the steady-state conditions for salt concentration is between 58 and 164 ka. This is a minimum age of the Marsh but it can be much older as nearly steady-state conditions could be maintained infinitely. Our approach

  6. 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.

  7. Characteristics of high arsenic groundwater in Hetao Basin, Inner Mongolia, northern China

    Institute of Scientific and Technical Information of China (English)

    YangChun Zhu; XueYong Zhao; Min Chen; YongQing Luo; Xin Zhou

    2015-01-01

    It is well known that the Hetao Basin is one of the most seriously arsenic-affected groundwater areas in China. In order to understand the characteristics of high arsenic (As) groundwater in the Basin, a brief overview of arsenic in groundwater follows. High arsenic in the Basin commonly occurs in shallow groundwater and the total arsenic concentrations range from 0.58 to 572 µg/L (average 99.73 µg/L), exceeding the maximum mandated value of 10 µg/L for drinking water in China;As(Ш) is the predominant species. The regional distribution pattern of arsenic in the groundwater increases from south/southeast to north/northwest. Hangjinhouqi and Wuyuan counties are considered as the most seriously affected areas, with high incidences of endemic arsenicosic diseases in the Hetao Basin. High groundwater arsenic correlates with the increase of well depth. Previous studies proposed that groundwater arsenic in the Basin is mainly originated from desorption of some natural solid materials in the sediments, under reducing condition. Generally, reducing condition is believed to be the primary factor for arsenic releasing from the sediment to groundwater in the region. Under inorganic or bacterial processes, Fe2O3 changes to FeS and arsenic adsorbed to Fe(OH)3 dissolves into groundwater, and As(V) is re-duced to As(Ш). Besides, reducing environments, groundwater hydraulic gradients, organic matter, pH, evapotranspiration, and soil texture are presumed to be the predominant factors that control arsenic mobilization.

  8. 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. PMID:26881457

  9. Uranium geology of the eastern Baker Lake basin, District of Keewatin, Northwest Territories

    International Nuclear Information System (INIS)

    Proterozoic sequences associated with major unconformities are potential uranium metallogenic provinces. Late Aphebian to Paleohelikian Dubawnt Group contintental clastic sedimentary and subaerial alkaline volcanic rocks and underlying Archean gneisses, District of Keewatin, Northwest Territories, represent one such uraniferous metallogenic province. Three types of uranium mineralization are present in the eastern Baker Lake basin, which extends from Christopher Island at the eastern end of Baker Lake southwestwards to the western limit of Thirty Mile Lake. The three uranium associations are: 1) fracture controlled mineralization in the Dubawnt Group and basement gneisses (U-Cu-Ag-Au-Se or U-Cu-Pb-Mo-Zn), 2)diatreme breccia mineralization in basement gneisses (U-Cu-Zn), and 3) impregnation and microfracture mineralization in altered arkose peripheral to lamprophyre dykes(U-Cu-Ag). Hydrothermal fracture related mineralization is controlled by northwest- and east-northeast-trending fault-fracture zones. Diatreme breccia mineralization results from the channelling of groundwaters through highly permeable brecciated gneiss. Mineralization within the altered Kazan arkose peripheral to alkaline dyke complexes formed by a two stage process. Iron and copper sulphides and silver were deposited within the outer portions of the thermal aureole in response to a temperature and Eh gradient across a convective cell created by the thermal anomaly of the dyke complex. The epigenetic sulphide mineralization subsequently provided the reducing environment for precipitation of uranium from groundwater. All three uranium associations show a close spatial distribution to the basal Dubawnt unconformity. The lithological and structural relationships of the Dubawnt Group rocks, types of mineralization and associated alteration assemblages are strikingly similar to the Beaverlodge district, Saskatchewan. (author)

  10. Relationship Between Agriculture and Ecological Deterioration, Restoration and Reconstruction in Loess Plateau Areas of Northwest China

    Institute of Scientific and Technical Information of China (English)

    CHENG Xu

    2002-01-01

    A comprehensive analysis was conducted on the current situation as well as historic succession process of agriculture and ecological conditions in Northwest China, in particular in the Loess Plateau, by means of a inter-disciplinary approach of ecology, agro-geohistory, and agronomy. It was concluded that the fundamental causes responsible for the ecological deterioration, signed by the poor agro-productivity and serious soil erosion, had been the extensive cropping system by ever-increasing reclamation on semi-drought slope land, where initiated a natural vegetation of brushy grasses with sparse trees, thus suitable only for animal husbandry. Based on an identification of specific actual status of China, several countermeasures of correctly dealing with the relationship between agricultural development and the ecological restoration and reconstruction were proposed, including to get breakthrough first in the transection area by means of the rational use of resources and the raising of agro-system productivity, to promoting "water conservancy-type ecological agriculture" through the radical shift of traditional production pattern, and the adoption of a policy of proper degree of grain self-reliance, as well as to construct livestock industry base in Northwest China.

  11. Effects of Water Priority Policy on Farmers' Decision on Acreage Allocation in Northwest China

    OpenAIRE

    Zhang, Lei; Herzfeld, Thomas

    2012-01-01

    This article analyses the impact of a water allocation priority policy for a specific crop on farmers’ acreage allocation to different crops. To accomplish this, a system of crop acreage demands conditional on output yields, prices of variable inputs and levels of quasi-fixed inputs is estimated. The analysis based on a two-year farm household panel data from an arid region in northwest China. The results show that the water policy change results in a lower elasticity of land demand not only ...

  12. Effects of Water Priority Policy on Farmer's Decision on Acreage Allocation in Northwest China

    OpenAIRE

    Herzfeld, T.; Lei Zhang

    2012-01-01

    This article analyses the impact of a water allocation priority policy for a specific crop on farmers’ acreage allocation to different crops. To accomplish this, a system of crop acreage demands conditional on output yields, prices of variable inputs and levels of quasi-fixed inputs is estimated. The analysis based on a two-year farm household panel data from an arid region in northwest China. The results show that the water policy change results in a lower elasticity of land demand not only ...

  13. 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.

  14. Observation of Directional Ocean Wave Spectra in China Seas and Northwest Pacific Ocean Using SAR Retrieval Software

    Science.gov (United States)

    Liu, Xiaoyan; Zeng, Kan; He, Mingxia

    2014-11-01

    A software to retrieve directional ocean wave spectra from SAR images has been developed for China seas and northwest Pacific. The software, written with C programming language, is based on the MPI method proposed by Hasselmann. It is designed to support the wave mode SAR data of ERS, Envisat, Sentinel and so on. The directional ocean wave spectra produced by this software are validated with buoy data in global ocean area, northwest Pacific and China seas and the retrieved significant wave height (SWH) errors are 5.2%, 4.9% and 9.3% respectively. About 15,000 directional ocean wave spectra are obtained with the software from the wave mode data of Envisat/ASAR over the China seas and northwest Pacific during the period between Jan 2003 and Jan 2012. The preliminary analysis is presented.

  15. Winter coastal upwelling off northwest Borneo in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    YAN Yunwei; LING Zheng; CHEN Changlin

    2015-01-01

    Winter coastal upwelling off northwest Borneo in the South China Sea (SCS) is investigated by using satellite data, climatological temperature and salinity fields and reanalysis data. The upwelling forms in Decem-ber, matures in January, starts to decay in February and almost disappears in March. Both Ekman trans-port induced by the alongshore winter monsoon and Ekman pumping due to orographic wind stress curl are favorable for the upwelling. Transport estimates demonstrate that the month-to-month variability of Ekman transport and Ekman pumping are both consistent with that of winter coastal upwelling, but Ek-man transport is two times larger than Ekman pumping in January and February. Under the influence of El Niño-Southern Oscillation (ENSO), the upwelling shows remarkable interannual variability: during winter of El Niño (La Niña) years, an anticyclonic (a cyclonic) wind anomaly is established in the SCS, which behaves a northeasterly (southwesterly) anomaly and a positive (negative) wind stress curl anomaly off the north-west Borneo coast, enhancing (reducing) the upwelling and causing anomalous surface cooling (warming) and higher (lower) chlorophyll concentration. The sea surface temperature anomaly (SSTA) associated with ENSO off the northwest Borneo coast has an opposite phase to that off southeast Vietnam, resulting in a SSTA seesaw pattern in the southern SCS in winter.

  16. 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

    2015-09-01

    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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Impact of Global Warming on Water Resource in Arid Area of Northwest China

    Institute of Scientific and Technical Information of China (English)

    LU Aigang; DING Yongjian; PANG Hongxi; YUAN Lingling; HE Yuanqing

    2005-01-01

    As the unprecedented global warming is under way, the glacier retreat is getting more and more serious. In the inland arid area of Northwest China, due to very scarce precipitation, where there is water, there are oases. And the glacier melt water amounts to 22 % of the total direct supply of the inland river water and is of crucial importance to the survival and development of the oases. In this paper,using both the observed data and the previous research achievements of the glaciers in the inland valley of Northwest China where the oasis depending on the glacier is the only location suitable for human living, the authors describe the glacier retreat trend over the past half century, focusing on discussing the possible impact of the glacier retreat on the melt water runoff that is almost the only water resource efficient to nourish the oases. The authors find that even with increasing amount of water from the glacier with global warming, the water shortage is getting more and more serious and the environment is under a degrading way due to the accelerating economical development. The water shortage is bound to be more serious if the glacier retreat keeps on, especially after the glacier melt water is over its top for the degraded glacier scale. So suggestions are stressed in the end that a new water-saving pattern should be adopted in the area for a sustainable development due to the warming-up induced continuous glacier retreat.

  2. REPORT OF HLA DISTRIBUTION IN 2315 VOLUNTEER DONORS OF CHINESE BONE MARROW BANK FROM NORTHWEST CHINA

    Institute of Scientific and Technical Information of China (English)

    Jin Tianbo; Gao Ya; Zhang Hongbo; Zhao Junhai; Lai Jianghua; Lai Shuping; Li Shengbin

    2005-01-01

    Objective To report the HLA data of volunteer donors of Chinese bank from Northwest China and characterize the distribution of HLA genes in Northwest China. Methods HLA-A, B antigens of 2315 volunteer donors were examined by the method of microlymphocytetoxicity (MLT) test .The antigen frequencies(AF) were assessed by directly counting; and based on that gene frequencies(GF) were calculated. HLA data from other population were collected and distribution characteristics were compared. With the raw data, Hardy-Weinberg equilibrium, statistical parameters of forensic medicine interest for HLA were computed. Results A total of 18 specific antigens were detected in HLA-A and the most frequent antigen was A2 . AF and GF were 0.5136 and 0.3026, respectively. A total of 42 specific antigens were detected in HLA-B and the most frequent antigen was A13. Its AF and GF were 0.1978 and 0.1044, respectively. The heterozygosity(H), polymorphism information content(PIC), discrimination power(DP) and probability of paternity exclusion (PPE) of HLA-A were 0.8215, 0.8212, 0.9356 and 0.7798 accordingly; while H,PIC, DP and PPE of HLA-B were 0.9322, 0.9322, 0.9878 and 0.9528. Conclusion The polymorphism of HLA-A,B genes is characteristic in Chinese. In this research, the genetic trait of HLA in 2315 volunteers is consistent with Northern Han population.

  3. Full-length genomic characterizations of two canine parvoviruses prevalent in Northwest China.

    Science.gov (United States)

    Han, Shi-Chong; Guo, Hui-Chen; Sun, Shi-Qi; Shu, Long; Wei, Yan-Quan; Sun, De-Hui; Cao, Sui-Zhong; Peng, Guang-Neng; Liu, Xiang-Tao

    2015-05-01

    Canine parvovirus (CPV) can cause acute hemorrhagic diarrhea and fatal myocarditis in young dogs. Currently, most studies have focused on the evolution of the VP2 gene, whereas the full-length genome of CPV has been rarely reported. In this study, the whole genomes of CPV-LZ1 and CPV-LZ2 strains prevalent in Northwest China were determined and analyzed in comparison with those of the reference CPVs. The genome sequences of both LZ strains consisted of 5053 nucleotides. CPV-LZ1 and CPV-LZ2 strains were designated as new CPV-2a and CPV-2b, respectively. Sequence alignment analysis results revealed that these two new strains underwent specific unique variations during the process of local adaption. The left non-translated regions of these strains formed a Y-shaped hairpin structure, whereas the right non-translated regions lacked the reiteration of DNA sequence. A phylogenetic tree constructed from 33 whole coding regions of CPVs showed a strong spatial clustering, and these two strains belonged to the Chinese strain cluster lineage. This study provides a method to obtain the full-length genome of CPV. The isolation and characterization of these viruses adds incrementally to the knowledge of the full-length genome of CPV. The results from this study also provide insight into the molecular epidemiology and genetic diversity of the CPV field isolates from Northwest China and can be useful in preventing and controlling CPV infection in this region. PMID:25690604

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Review and proposals on vegetation restoration in the Loess Plateau, Northwest China

    Institute of Scientific and Technical Information of China (English)

    Wenhui ZHANG; Guobin LIU

    2008-01-01

    A group of scientists conducted a comprehen-sive investigation on ecological safety and water and soil erosion in the Northwest Loess Plateau, Northwest China. The data gathered was analyzed in terms of achievement, existing problems, and strategy and mea-sures on vegetation restoration in the area. Since the policies of conversion from cropland to forest (CCF) and forbid grazing and cutting (FGC) were carried out, vegetation quality and coverage rate increased quickly in the Loess Plateau area, strengthening the concept of eco-environment protection. Environment harness measure-ments were optimized. The multiform investments on eco-environment and urbanization development in China will benefit vegetation restoration. However, there have been some persisting problems, such as the shortage of investment, instability of government policy, expectation of extravagant economic benefit, larger rate of planta-tion, and scarce technologies supporting vegetation restoration. Many key theories and practice problems require an urgent resolution. In the future, short-, mid-,and long-term goals for vegetation restoration should be clear, achievement should be expanded, and the natural restoration area should be increased. The benefit for the contractor on vegetation restoration should be ensured. Investment on vegetation building research work should be increased.

  6. Basin-mountain structures and hydrocarbon exploration potential of west Junggar orogen in China

    Science.gov (United States)

    Wu, Xiaozhi; He, Dengfa; Qi, Xuefeng

    2016-04-01

    Situated in northern Xinjiang, China, in NE-SW trend, West Junggar Orogen is adjacent to Altai fold belt on the north with the Ertix Fault as the boundary, North Tianshan fold belt on the south with the Ebinur Lake Strike-slip Fault as the boundary, and the Junggar Basin on the southeast with Zaire-Genghis Khan-Hala'alat fold belt as the boundary. Covering an area of about 10×104 km2 in China, there are medium and small intermontane basins, Burqin-Fuhai, Tacheng, Hefeng and Hoxtolgay, distributing inside the orogen. Tectonically West Junggar Orogen lies in the middle section of the Palaeo-Asian tectonic domain where the Siberia, Kazakhstan and Tarim Plates converge, and is the only orogen trending NE-SW in the Palaeo-Asian tectonic domain. Since the Paleozoic, the orogen experienced pre-Permian plate tectonic evolution and post-Permian intra-plate basin evolution. Complex tectonic evolution and multi-stage structural superimposition not only give rise to long term controversial over the basin basement property but also complex basin-mountain coupling relations, structures and basin superimposition modes. According to analysis of several kinds of geological and geophysical data, the orogen was dominated by compressive folding and thrust napping from the Siberia plate in the north since the Late Paleozoic. Compressive stress weakened from north to south, corresponding to subdued vertical movement and enhanced horizontal movement of crustal surface from north to south, and finally faded in the overthrust-nappe belt at the northwest margin of the Junggar Basin. The variation in compressive stress is consistent with the surface relief of the orogen, which is high in the north and low in the south. There are two kinds of basin-mountain coupling relationships, i.e. high angle thrusting and overthrusting and napping, and two kinds of basin superimposition modes, i.e. inherited and progressive, and migrating and convulsionary modes. West Junggar orogen has rich oil and gas

  7. 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

  8. The Basin Water Resources Management System and Its Innovation in China

    Institute of Scientific and Technical Information of China (English)

    Xun; Pomponio

    2008-01-01

    Water provides the origin of human survival and prosperity,and the basic resource for the maintenance of terrestrial eco-systems,their biodiversity,productivity and ecological services.With China’s recent,rapid growth both in population and economic development,the water shortage has become one of the most constraints on its ecological restoration and socio-economic development,especially in the arid inland regions of northwest China.At first glance,this water shortage in China appears to be a resource crisis.But second,an in-depth analysis reveals that the water shortage crisis arises mainly resulting from the poor water management system and operating mechanism that cannot facilitate fair allocation and efficient utilization of water resources both regionally and nationally and thus is viewed as a crisis of water manage-ment.The solution of China’s water shortage and low-efficient utilization problem will,in particular,require a fundamen-tal and substantial reform or innovation of the existing water management system and operating mechanism.In this paper,we address explicitly the problems existed in the current water management system,explore the basic theory of water re-sources management and provide some insights into the way how to establish a river basin based integrated water re-sources management system in China.

  9. Lithologic Hydrocarbon Deposits in Rift Lake Basins in Eastern China

    Institute of Scientific and Technical Information of China (English)

    ZHENG Herong; HE Zongquan

    2004-01-01

    The rift lake basins in the eastern China have abundant hydrocarbon resources of lithologic deposits, which resulted from excellent source rocks and multi-type sandbodies developed during strong rifting. Vertically, the lithologic deposits are mainly distributed in the lowstand, lacustrine invasion and early highstand systems of third-order sequence corresponding to a secondary tectonic episode of strong rifting, and laterally they are closely related to various fans and turbidite sandbodies controlled by syn-sedimentary faults. A variety of lithologic traps have been developed in the rift lake basins, and they generally have favorable conditions of source-reservoir-seal assemblage and hydrocarbon accumulation dynamics, indicating that there is a great exploration potential of lithologic deposits in the rift lake basins.In order to obtain satisfactory effects of lithologic deposit exploration, it is required to combine new theories with advanced technical methods.

  10. 40Ar/39Ar ages of seamount trachytes from the South China Sea and implications for the evolution of the northwestern sub-basin

    Institute of Scientific and Technical Information of China (English)

    Xiaohu Li; Jiabiao Li; Xing Yu; Chunsheng Wang; Fred Jourdan

    2015-01-01

    A chronological study of seamount rocks in the South China Sea basin provides a great opportunity to understand the expansion and evolution history of the sea basin. In this paper, we analyzed the 40Ar/39Ar age of trachytic samples collected from the Shuangfeng seamounts in the northwestern sub-basin of the South China Sea. The two samples yielded plateau ages of 23.80 ? 0.18 and 23.29 ? 0.22 Ma, respectively, which indicate magmatic activity in late Oligocene which helpful constraints the expansion time of the northwest sub-basin. Previous studies suggested that the northwestern sub-basin and southwestern sub-basin have experienced a relatively consistent expansion in the NWeSE direction followed by a late expansion of the eastern sub-basin. We concluded that the expansion of the northwestern sub-basin began prior to ca. 24 Ma, which also implicated magmatic events of a late or stop expansion of the northwestern sub-basin combined with our results of 40Ar/39Ar age data and previous geophysical data.

  11. Integrated Water and Sanitation Risk Assessment and Modeling in the Upper Sonora River basin (Northwest, Mexico)

    Science.gov (United States)

    Mayer, A. S.; Robles-Morua, A.; Halvorsen, K. E.; Vivoni, E. R.; Auer, M. T.

    2011-12-01

    Studies that integrate human dimensions and the biophysical characteristics of watersheds are necessary to meet the challenge of sustainable water resources development. In this project, we integrated perspectives from sociology, hydrology, and environmental engineering to examine and suggest solutions for managing waterborne disease risks associated with wastewater contamination in the Sonora River basin (SRB), a semiarid rural basin in northwest Mexico. This research consisted of four sub-projects. First, we assessed the perceptions of risks associated with wastewater contamination of water resources in rural communities in the SRB through a series of semi-structured interviews Results from this study indicate that there are major differences in risk perceptions among health professionals, government officials, and lay citizens. Government officials and lay citizens tend to underestimate the severity of the problems related to water related risks. Second, a fully distributed hydrologic model was used to make streamflow predictions in the un-gauged SRB. Synthetic flows generated from the hydrologic model were used to evaluate pollutant transport processes associated with wastewater loadings to the Sonora River. The hydrologic model revealed that the high degree of spatio-temporal variability of runoff in the SRB is associated with links between runoff generation mechanisms and land-atmosphere interactions. Third, a surface water quality model was used to assess the impact of wastewater discharges and develop pathogen contamination indicators in two sites along the Sonora River. To parameterize the water quality model, pathogenic indicator loadings and removal rates were estimated, along with their uncertainty. Results from the water quality modeling show regions in the watershed that may be exceeding pathogenic standards, but also that uncertainty in model parameters requires a probabilistic approach for estimating risks. Finally, a workshop was conducted to

  12. Detrital zircon provenance and paleogeography implications for Furnas Formation in the northwest of Paraná Basin

    Directory of Open Access Journals (Sweden)

    Thais Borba Santos

    2015-06-01

    Full Text Available In the northwest of the Paraná Basin, between the states of Mato Grosso and Goiás, there are exposures of the Furnas Formation, where the Transbrasiliano Lineament is also recognized. From the analysis of magnetic maps, the geological and geophysical framework of the study area was defined, with six main domains separated by 5 lineaments. The contact between Paraguay Belt and the Goiás Magmatic Arc is marked by the main direction of the Transbrasiliano Lineament in the study area. Other lineaments that occur associated with the deformation direction of the Paraguay Belt have been identified as a minor component of Transbrasiliano Lineament. The description of outcrops along the northwest border of the Paraná Basin allowed the recognition of units I, II and III of the Furnas Formation. The U-Pb data from detrital zircon from the Furnas Formation showed predominance of grain with Neoproterozoic ages (560 - 800 Ma, with a minimum age of 526 Ma, and the occurrence of grain with Paleoproterozoic (≈1750/2100 Ma and Archean (≈2700/2800/3100 Ma ages. The study of detrital zircons provenance of the Furnas Formation using U-Pb age determination, associated with the structural framework of the foundation of the basin, and the comparison with paleoenvironmental data were the basis for assessing the paleogeography of the northwestern portion of the Paraná Basin during the aggradation of the Furnas Formation. Ages indicate an important Neoproterozoic contribution similar to the ages of the rocks found in the Goias Magmatic Arc, which associated with data of paleocurrents towards northwest allow us to infer that the arc rocks constituted high terrain, oriented in the NE-SW direction.

  13. Seismic interpretation of dinantian carbonate platforms in the Netherlands; implications for the palaeogeographical and structural development of the Northwest European Carboniferous Basin

    NARCIS (Netherlands)

    Kombrink, H.; Lochem, H. van; Zwan, K.J. van der

    2010-01-01

    The Northwest European Carboniferous Basin is characterized by a series of carbonate platforms and intervening shale-dominated troughs during the Dinantian Sub-period. These structures have been mainly found along the margins of the basin. Here we present the results of an investigation of high-qual

  14. Dust aerosol effect on semi-arid climate over Northwest China detected from A-Train satellite measurements

    OpenAIRE

    Huang, J; Minnis, P.; Yan, H; Yi, Y.; Chen, B; Zhang, L.; J. K. Ayers

    2010-01-01

    The impact of dust aerosols on the semi-arid climate of Northwest China is analyzed by comparing aerosol and cloud properties derived over the China semi-arid region (hereafter, CSR) and the United States semi-arid region (hereafter, USR) using several years of surface and A-Train satellite observations during active dust event seasons. These regions have similar climatic conditions, but aerosol concentrations are greater over the CSR. Because the CSR is close to two major dust source regions...

  15. Molecular Epidemiological Investigation of Porcine kobuvirus and Its Coinfection Rate with PEDV and SaV in Northwest China

    OpenAIRE

    Chen Wang,; Xi Lan; Bin Yang

    2016-01-01

    Porcine kobuvirus (PKV) has circulated throughout China in recent years. Although many studies have detected it throughout the world, its molecular epidemiology has not been characterized in northwest China. To understand its prevalence, 203 fecal samples were collected from different regions of Gansu Province and tested with reverse transcription-polymerase chain reaction. In this study, we tested these samples for PKV, porcine epidemic diarrhea virus (PEDV), and sapovirus and analyzed the a...

  16. 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.

  17. Yardangs in the Qaidam Basin, northwestern China: Distribution and morphology

    Science.gov (United States)

    Li, Jiyan; Dong, Zhibao; Qian, Guangqiang; Zhang, Zhengcai; Luo, Wanyin; Lu, Junfeng; Wang, Meng

    2016-03-01

    The northwestern Qaidam Basin exposes one of the largest and highest elevation yardang fields on Earth. The aim of the present study was to describe the distribution and morphology of these yardangs, and analyze the factors responsible for the distribution pattern of these aeolian landforms. The yardang fields are bounded by piedmont alluvial-diluvial fans from the mountain ranges surrounding the basin, except in the south, where they are bounded by dune fields, dry salt flats, lakes, and rivers. This distribution pattern can be attributed to regional tectogenesis and its corresponding environmental impacts. The morphology of the yardangs varies considerably in response to the diverse factors that control their formation and evolution. Long-ridge yardangs are mainly located in the northernmost part of the yardang field, and the long ridges are gradually dissected into smaller ridges in the downwind direction. Further downwind, the convergence of northerly and northwesterly winds and the effects of temporary runoff cause the ridges to gradually transition into mesa yardangs. Saw-toothed crests, and conical and pyramidal yardangs, occur in groups on folded brachyanticlinal structures. Typical whaleback yardangs are found in the southeast, at the northern margin of Dabuxun Lake. Morphological parameters vary among the yardang types. The orientation of the yardangs in the northernmost area is nearly N-S, with a transition towards NW-SE in the southernmost area in response to a change in the dominant wind direction that results from the orientations and positions of the mountain ranges that surround the basin.

  18. Year aridity index patterns in northwest China and the relationship to summer North Atlantic sea surface temperature

    Institute of Scientific and Technical Information of China (English)

    YAN Yan; ZHAO Xinyi; ZHOU Liping

    2008-01-01

    Aim to linking the variability of drought in northwest China to the oceanic influence of North Atlantic SSTs at the background of global warming and at the regional climate change shifting stages, year aridity index variations in northwest China and summer North Atlantic sea surface temperature (SST) variations are examined for the 44 a period of 1961--2004 using singular value de-composition (SVD) analysis. Results show that the SST anomalies (SSTA) in the North Atlantic in summer reflected three basic models. The first SVD mode of SST pattern shows a dipole - like variation with the positive center located at southwest and nega-tive center at northeast of extratropical North Atlantic. And it strongly relates to the positive trend in AI variation in northwest China. The second coupled modes display the coherent positive anomalies in extratropical North Atlantic SST and the marked opposite trend of AI variability between north and south of Xinjiang. In addition, the lag correlation analysis of the first mode of SSTA and geopotential heights at 500 hPa variations also shows that the indication of the former influencing the latter configuration, which re-sult in higher air temperature and less precipitation when the SSTA in the North Atlantic Ocean in summer motivated Eurasian cir-culation of EA pattern, further to influence the wet - dry variations in northwest China by the ocean-to - atmosphere forcing.

  19. Sedimentary basin analysis using airborne gravity data: a case study from the Bohai Bay Basin, China

    Science.gov (United States)

    Li, Wenyong; Liu, Yanxu; Zhou, Jianxin; Zhou, Xihua; Li, Bing

    2015-12-01

    In this paper, we discuss the application of an airborne gravity survey to sedimentary basin analysis. Using high-precision airborne gravity data constrained by drilling and seismic data from the Bohai Bay Basin in eastern China, we interpreted faults, structural elements, sedimentary thickness, structural styles and local structures (belts) in the central area of the Basin by the wavelet transform method. Subsequently, these data were subtracted from the Bouguer gravity to calculate the residual gravity anomalies. On this basis, the faults were interpreted mainly by linear zones of high gravity gradients and contour distortion, while the sedimentary thicknesses were computed by the Euler deconvolution. The structural styles were identified by the combination of gravity anomalies and the local structures interpreted by the first vertical derivative of the residual gravity. The results showed evidence for seven faults, one sag and ten new local structure belts.

  20. Agricultural reclamation policy and environmental changes In the northwest China during the Qing dynasty

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhen

    2006-01-01

    Northwest China,including the provinces of Shaanxi,Gansu,Ningxia,and a small part of the Inner Mongolian Autonomous Region,was not only one of the earliest developed areas in history,but also one of the most ecologically fragile belts.The traditionally sustainable land reclamation and cultivation policies for the development of an agricultural economy adopted and implemented in administrations during different periods of the Qing dynasty,greatly raised farming and stock production.However,this led to imbalances in the originaUy fragile ecological environment.The negative effects such as rapidly expanding desertification,worsening water and soil erosions,increased cost of production,enlarged investment,vicious cycles and failing economy can serve as a lesson for contemporary development.

  1. A landscape approach to quantifying land cover changes in Yulin, Northwest China.

    Science.gov (United States)

    Zha, Yong; Liu, Yansui; Deng, Xiangzheng

    2008-03-01

    In this study we quantified land cover changes in the arid region of Yulin City, Northwest China between 1985 and 2000 using remote sensing and GIS in conjunction with landscape modeling. Land covers were mapped into 20 categories from multitemporal Landsat TM images. Five landscape indices were calculated from these maps at the land cover patches level. It was found that fallow land decreased by 125,148 ha while grassland and woodland increased by 107,975 and 17,157 ha, respectively. Landscape heterogeneity, dominance and fractal dimension changed little during the 15-year period while landscape became more fragmented, with an index rising from 0.56 to 0.58. The major factors responsible for these changes are identified as the change in the government policy on preserving the environment, continued growth in mining, and urbanization. PMID:17492483

  2. Water Pricing Policy in Tarim Basin of China

    Institute of Scientific and Technical Information of China (English)

    施祖麟; 许丽芬

    2001-01-01

    China ranks the thirteenth among countries with serious water shortage problems in the world. The average amount of water owned per person is only 2400 m3/year, which is about 1/4 of the world average. But unfortunately, the efficiency of water use, especially in agriculture in some arid areas, is very low, only 20% -30% in some areas. The main reason is that water prices are too iow to protect the water resources. In this paper, the Tarim Basin of southern Xinjiang is selected to study the water supply costs and farmer's tolerance of water expenses based on a great amount of data collected in the four prefectures in the Tarim Basin. Then, three steps are suggested for water pricing reform in the Tarim Basin. Finally, several possible water pricing patterns are presented, such as water coupons, seasonal floating prices, and water price counting in kind but paying in currency. The conclusion is that the present water price system should be reformed and the water price can be increased to some extent for agricultural use even in Xinjiang, a developing area in China.

  3. Epidemiological study of a von Hippel-Lindau family in northwest China.

    Science.gov (United States)

    Zhang, Jingyao; Wu, Dapeng; Ai, Hong; Bai, Jigang; Dong, Shunbin; Yang, Qinling; Qu, Kai; Zhou, Lei; Xu, Xinsen; Liu, Chang

    2013-09-01

    von Hippel-Lindau (VHL) disease is a rare, inherited neoplastic disease characterized by hemangioblastomas (HBL) of the central nervous system (CNS), retinal angiomas, renal cell carcinomas (RCC), pancreatic endocrine tumors (PETs), pheochromocytomas, paragangliomas, and visceral cysts. We encountered a large VHL family in northwest China and conducted a systematic screening of the family members based on their epidemiological and clinical characteristics. A self-designed questionnaire was used to collect the general sociodemographic and health information of the family members. For the preliminary family screening, physical examination and abdomen B ultrasonography were performed. The suspected patients were subjected to cranial computerized tomography and fundus examination. The clinical data of the patients with confirmed VHL disease were collected from hospital records. A total of 63 lineal descendants in six generations were observed in the family (generations O, A, B, C, D, E), including 9 dead suspected cases (6 males, 3 females) and 10 living cases (2 males, 8 females). Among the 10 living cases, 4, 2, 1, 3, 4, 8, and 2 manifested HBLs of the CNS, PETs, RCC, pancreatic cysts, renal cysts, pheochromocytomas (4 hemi and 4 bilateral), and paragangliomas, respectively. Data showed that the morbidity of VHL disease in generation C was lower than that in generation B, but the age of onset was younger. This study is the first to report VHL disease in northwest China and VHL-associated PET cases in Chinese. Therefore, follow-up checkups of the family should be focused on younger generations. Proper family screening protocols should be followed for the treatment of patients with VHL disease. PMID:23827964

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

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

    Background 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.Methods 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.Results 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 neighbors

  5. Salt-related tectonics in the eastern Sichuan Basin, South China

    Science.gov (United States)

    Gu, Zhidong; Yin, Jifeng; Yuan, Miao; Zhai, Xiufen

    2015-04-01

    Sichuan Basin is located in the northwest of Upper Yangtze platform of South China, and East Sichuan is situated between Huaying Mountain fault and Qiyue Mountain fault. The surface Jura type folds are very famous with barrier parallel folds, but the cause of folds formation have not been completely understood. Stratigraphic units are composed of thick competent flexural layers separately by relatively thin incompetent ductile layers that can act as detachments.Multiple detachment layers are developed in the eastern Sichuan and result in distinct structural domains. In addition to the basal, Triassic and Silurian system detachment layers, we recognize a regionally extensive salt layer in the Middle and Lower Cambrian. The recognition of salt layer is by the synthetical studies of outcrop, drilling well, and chaotic seismic reflection configuration. The Middle and Lower Cambrian salt forms a tectonic domain boundary that can be observed by seismic reflection profile in subsurface. The stratigraphic intervals above and below the salt develop characteristic salt-related tectonics. And the folds formation is by flow in and flow out of salt movement of the Middle and Lower Cambrian and flexural slip and grouding of the overlying units. Above the salt, the thrust fault-related folds were generated by the contractional action from southeast to northwest, including the fault-bend fold, fault-propagation fold, and thrust wedge fold, and so on. Below the salt, the broad anticlines were formed due to the basal detachment. Hydrocarbon traps are formed above and below the salt, and they are potential gas exploration domains in the eastern Sichuan Basin.

  6. The structure and sedimentary sequence of intracratonic rift from Late Sinian to Early Cambrian in the Sichuan Basin, South China

    Science.gov (United States)

    Gu, Zhidong; Zhang, Baomin; Lu, Weihu; Zhai, Xiufen; Jiang, Hua

    2016-04-01

    Sichuan Basin is located in the northwest of Upper Yangtze craton of South China, and there is developed an intracratonic rift from Late Sinian to Early Cambrian in the middle of Sichuan Basin, and the paper systematically discusses the structure and sedimentary sequence of the intracratonic rift based on the fields, drilling and seismic data, and so on. Detailed structural interpretation of 2D and 3D seismic profiles displays the development of two stages of intracratonic rift due to regional extension with the depth of 2000m, and plane distribution of intracratonic rift presents the V-pattern from the northwest to the southeast in the middle of Sichuan Basin with the width from 100km to 20km. The drilling data from the intracratonic rift shows the obvious thinning of Upper Sinian and thickening of Lower Cambrian. And field outcrops situated in the intracratonic rift reveal that the Upper Sinian is mainly composed of siliceous rock, shale and carbonate, with the thickness of less than 100m, but the thickness of Upper Sinian on the platform reaches 1000m by contrast; They also reveals that Lower Cambrian is mainly composed of shale, mudstone, and siltstone with the development of gravity current, and the thickness of Lower Cambrian reaches 2000m. The formation of intracratonic rift may be initiated by pre-existing basement weakness zone and deep mantle dynamics.

  7. Modeling impacts of management alternatives on soil carbon storage of farmland in Northwest China

    Directory of Open Access Journals (Sweden)

    F. Zhang

    2006-05-01

    Full Text Available Long-term losses of soil organic carbon (SOC have been observed in many agriculture lands in Northwest China, one of the regions with the longest cultivation history in the world. The decline of SOC contents not only impaired the soil fertility but also increased the amount of carbon dioxide (CO2 emitted from terrestrial ecosystems into the atmosphere. However, quantifying the SOC losses at regional scale has long been remaining unsolved. A process-based model, Denitrification-Decomposition or DNDC, was adopted in the study to quantify impacts of farming management practices on SOC dynamics for a selected region, Shaanxi Province. The selected domain, with 3 million hectares of cropland across different climatic and farming management regimes, is representative for the major agricultural areas in Northwest China. The DNDC model was tested against long-term SOC dynamics observed at five agricultural sites in China. The agreement between the observed and modeled results indicate that DNDC was capable of capturing patterns and magnitudes of SOC changes across the climate zones, soil types, and management regimes in China. To quantify SOC dynamics for Shaanxi, we constructed a GIS database to hold all of the DNDC-required input information (e.g., weather, soil properties, crop acreage, and farming practices for all the farmland in the studied domain. Sensitivity tests indicated the spatial heterogeneity of soil properties, especially initial SOC content, was the major source of uncertainty for the modeled SOC dynamics at regional scale. The Most Sensitive Factor (MSF method was employed in the study to quantify the uncertainties produced from the upscaling process. The results from the regional simulations for Shaanxi indicated that (1 the overall 3 million hectares of farmland in the province was a source of atmospheric CO2 with 0.5 Tg C yr−1 lost in 2000 under the current farming

  8. [Spatiotemporal variation characteristics and related affecting factors of actual evapotranspiration in the Hun-Taizi River Basin, Northeast China].

    Science.gov (United States)

    Feng, Xue; Cai, Yan-Cong; Guan, De-Xin; Jin, Chang-Jie; Wang, An-Zhi; Wu, Jia-Bing; Yuan, Feng-Hui

    2014-10-01

    Based on the meteorological and hydrological data from 1970 to 2006, the advection-aridity (AA) model with calibrated parameters was used to calculate evapotranspiration in the Hun-Taizi River Basin in Northeast China. The original parameter of the AA model was tuned according to the water balance method and then four subbasins were selected to validate. Spatiotemporal variation characteristics of evapotranspiration and related affecting factors were analyzed using the methods of linear trend analysis, moving average, kriging interpolation and sensitivity analysis. The results showed that the empirical parameter value of 0.75 of AA model was suitable for the Hun-Taizi River Basin with an error of 11.4%. In the Hun-Taizi River Basin, the average annual actual evapotranspiration was 347.4 mm, which had a slightly upward trend with a rate of 1.58 mm · (10 a(-1)), but did not change significantly. It also indicated that the annual actual evapotranspiration presented a single-peaked pattern and its peak value occurred in July; the evapotranspiration in summer was higher than in spring and autumn, and it was the smallest in winter. The annual average evapotranspiration showed a decreasing trend from the northwest to the southeast in the Hun-Taizi River Basin from 1970 to 2006 with minor differences. Net radiation was largely responsible for the change of actual evapotranspiration in the Hun-Taizi River Basin. PMID:25796880

  9. Profiler-sonobuoy measurements in the South China Sea basin

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, W.J.; Kumar, N.; Houtz, R.E.

    1979-07-10

    Analyses of single-channel seismic reflection profiles, and wide-angle reflection and refraction data from sonobuoys, indicate that the deep part of the South China Sea basin is typically oceanic in structure, except that layer 2 is about 1 km thicker than usual and layer 3 is only about half the usual thickness. The top of layer 2 has a rough upper surface and becomes deeper in the northern part of the basin, where it is overlain by sediments of velocity 1.7--3.8 km/s up to 3 km thick. A 6-km-thick sequence of sediments fills a basement depression just north of the outer subsurface (peripheral) ridge of the Sunda shelf. Thick sediments were measured at the outer parts of the Sunda shelf, Palawan shelf, Northeast Borneo shelf, and in the Taiwan straits south of the Penghu-Peikang basement high. The Manila trench is divided into two sections, a sediment-filled trench between southernmost Taiwan and Stewart bank off central northern Luzon and a topographic trench between Stewart bank southward into the Mindoro straits. Burial of part of the trench by sediments that thicken to the north and the thick sediment cover of the northern South China Sea basin indicate provenance from the north. The northern margin of the South China Sea basin is predominantly a zone of tension the southern margin is predominantly a zone of compression, the western margin may be a zone of shear, and the eastern margin is a subduction zone. It seems probable that the southern margin of the basin, called the Reed bank crustal block, was formerly attached to mainland Asia. Sometime during the Paleogene the Reed bank crustal block broke away from the continent, and new sea floor was created between the southeastward migrating block and the Asian mainland. Old ocean crust in front of the advancing block was subducted along the northwestern sides of Borneo and Palawan. Subduction ceased in the early Miocene with the collision of the crustal block and the Borneo-Palawan isthmian ridge.

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

    International Nuclear Information System (INIS)

    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

  11. THE STUDY OF POPULATION GENETIC RELATION AMONG TEN ETHNIC GROUPS IN NORTHWEST CHINA

    Institute of Scientific and Technical Information of China (English)

    康龙丽; 金天博; 陈腾; 李生斌

    2004-01-01

    Objective To investigate the genetic relation among ten ethnic groups in northwest China. Methods Allele frequencies of six STR(short tandem repeat ) loci in D13S1358, VWA, FGA, D5S818, D13S317, and D7S820 were collected from Lasa Tibetan, Changdu Tibetan, Xian Han, Gansu Dongxiang, Gansu Yugu, Xinjiang Uygur, Ozbak, Kirgiz, Sibe, Ningxia Hui by the results of State Key laboratory, Forensic Science Department, school of medical, Xian Jiaotong University and internet biological information data bank, and compared with that of the Mongolian, Zhuang in China, and White and Negro in USA. The polymorphism index (H, DP, PPE, PIC) and genetic distance, then the phylogenetic tree of all population were reported. Results The resulting tree topology exhibited strong geographic and racial partitioning consistent with that obtained with HLA and classical genetic polymorphisms. Conclusion The results suggest that forensic STR loci may be particularly powerful tools and provide the necessary fine resolution for the reconstruction of recent human evolutionary history.

  12. 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.

  13. Clay Mineral Distribution Patterns of Tertiary Continental Oil-bearing Basins in China

    Institute of Scientific and Technical Information of China (English)

    Zhao Xingyuan

    1996-01-01

    @@ Induction This paper studies the clay mineral distribution patterns of Tertiary continental oil-bearing basins in China. More than 9 000 shale samples from Paleogene (E) to Neogene (N) Series distributed in Bohai Gulf, Subei, Jianghan,Nanxiang, Zhoukou, Sanshui, Beibu Bay, East China Sea,Hetao, Juiquan, Qaidam and Tarim basins, and so on.

  14. Suggestion of a dynamic model of North China basin-range system

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    It is found from preliminary studies that previous basin-range models have difficulties in explaining the formation of the Mesozoic North-China basin-range system. This work suggests a new model-"tectonic thermal erosion" model, which considers the North China basin of Late Mesozoic and its peripheral ranges as a unified system, identifies relationship between upwelling and lateral spreading of the asthenolith with horizontal movement and deformation of the upper crust in the system, clarifies the effects of underplating erosion on the crustal evolution, and tries to establish an earth-dynamic model of the North China Mesozoic basin-range supported by numerical simulation.

  15. Characteristics of water isotopes and hydrograph separation during the spring flood period in Yushugou River basin, Eastern Tianshans, China

    Indian Academy of Sciences (India)

    Xiaoyan Wang; Zhongqin Li; Edwards Ross; Ruozihan Tayier; Ping Zhou

    2015-02-01

    Many of the river basins in northwest China receive water from melting glaciers and snow in addition to groundwater. This region has experienced a significant change in glacier and snowpack volume over the past decade altering hydrology. Quantifying changes in water resources is vital for developing sustainable strategies in the region. During 2013, a water-isotope source apportionment study was conducted during the spring flood in the Yushugou River basin, northwestern China. The study found significant differences in water isotopes between river water, snowmelt water, and groundwater. During the study period, the isotopic composition of groundwater remained relatively stable. This stability suggests that the groundwater recharge rate has not been significantly impacted by recent hydro-climatic variability. The river water flow rate and water 18O displayed an inverse relationship. This relationship is indicative of snowmelt water injection. The relative contribution of the two sources was estimated using a two-component isotope hydrograph separation. The contribution of snowmelt water and groundwater to Yushugou River were ∼63% and ∼37%, respectively. From the study, we conclude that snowmelt water is the dominant water source to the basin during the spring melt period.

  16. Tectonics and Petroleum Potential of the East China Sea Shelf Rift Basin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    There are two Cenozoic sedimentary basins in the East China Sea. They are the East China Sea shelf basin and the Okinawa Trough basin. The former can be divided into a western and an eastern rift region. The development of the shelf basin underwent continental-margin fault depression, post-rift and then tectonic inversion stages. Available exploration results show that the distribution of source rocks is controlled by the basin architecture and its tectonic evolution. In the Xihu depression, mudstones and coals are the main source rocks. The eastern rift region has good geological conditions for the formation of large oil and gas fields.

  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. 滇西北金沙江流域云南红豆杉群落种内与种间竞争%Intra-and interspecific competitions of Taxus yunnanensis population in Jinsha River Basin of northwest Yunnan Province, Southwest China

    Institute of Scientific and Technical Information of China (English)

    李帅锋; 刘万德; 苏建荣; 郎学东; 张志钧

    2013-01-01

    通过对滇西北金沙江流域云南红豆杉群落45株对象木及205株竞争木的调查,运用Hegyi的单木竞争指数计算了濒危保护植物云南红豆杉的种内和种间竞争强度.结果表明:云南红豆杉的种内竞争强度随径级的分布呈偏蜂曲线,径级在5 ~10 cm时最大,然后随径级的增加竞争强度呈减少的趋势;云南红豆杉的种间竞争强度(133.61)显著高于其种内竞争强度(76.88),其竞争压力主要来自于种间竞争;云南红豆杉的物种种内种间竞争强度大于丽江铁杉、亮叶杜鹃、红桦、川杨、川滇高山栲、少毛云南楤木等当地常见乔木物种,它们的竞争强度都在5以上;云南红豆杉与整个林分及伴生树种的竞争指数与对象木的胸径之间呈显著负相关,且均服从幂函数关系(CI=aDb),对象木胸径越大,其竞争压力越小.%Based on the investigations of 45 objective trees and 205 competitive trees of Taxus yunnanensis population in the Jinsha River Basin of northwest Yunnan Province and by using He-gyi' s single-tree competition index model, this paper analyzed the intra- and interspecific compe-tition intensities of endangered plant T. yunnanensis. The intraspecific competition intensity of T. yunnanensis decreased with its increasing diameter at breast height (DBH) , presenting a par-tial peak curve, whereas the intraspecific competition intensity of T. yunnanensis was the highest at its DBH 5-10 cm, and then showed a decreasing trend with the increase of the DBH. The in-terspecific competition intensity (133.61) of T. yunnanensis was significantly higher than the in-traspecific competition intensity (76. 88), indicating that the competitive stress of the T. yun-nanensis population was mainly come from interspecific competition. The intra- and interspecific competition intensities of T. yunnanensis were larger than those of the local common tree species Tsuga forrestii, Betula albo-sinensis, Populus

  19. New Progress in Petroleum Exploration of Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    Liang Digang

    1994-01-01

    @@ Basin Situation Tarim Basin located in the northwest of China, is one of the few largest basins in the world that haven't been well-explored, covering an area of 560 000km2, a little bit larger than that of France.

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

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

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

    2015-01-01

    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 over...

  2. 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.

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

    OpenAIRE

    Li, Y.; W. Kinzelbach; Zhou, J.; G. D. Cheng; Li, X.

    2012-01-01

    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 measurement...

  4. Carbon accumulation in arid croplands of northwest China: pedogenic carbonate exceeding organic carbon

    Science.gov (United States)

    Wang, Xiujun; Wang, Jiaping; Xu, Minggang; Zhang, Wenju; Fan, Tinglu; Zhang, Juan

    2015-06-01

    Soil carbonate (SIC) exceeds organic carbon (SOC) greatly in arid lands, thus may be important for carbon sequestration. However, field data for quantifying carbonate accumulation have been lacking. This study aims to improve our understanding of SIC dynamics and its role in carbon sequestration. We analyzed two datasets of SOC and SIC and their 13C compositions , one with over 100 soil samples collected recently from various land uses in the Yanqi Basin, Xinjiang, and the other with 18 archived soil samples from a long-term experiment (LTE) in Pingliang, Gansu. The data from the Yanqi Basin showed that SOC had a significant relationship with SIC and pedogenic carbonate (PIC); converting shrub land to cropland increased PIC stock by 5.2 kg C m-2, which was 3.6 times of that in SOC stock. The data from the LTE showed greater accumulation of PIC (21-49 g C m-2 year-1) than SOC (10-39 g C m-2 year-1) over 0-20 cm. Our study points out that intensive cropping in the arid and semi-arid regions leads to an increase in both SOC and PIC. Increasing SOC through straw organic amendments enhances PIC accumulation in the arid cropland of northwestern China.

  5. An Observed Connection Between Wintertime Temperature Anomalies over Northwest China and Weather Regime Transitions in North Atlantic

    Institute of Scientific and Technical Information of China (English)

    李超; 张庆云

    2015-01-01

    In this study, the association between wintertime temperature anomalies over Northwest China and the weather regime transitions in North Atlantic on synoptic scale is analyzed by using observational surface air temperature (SAT) data and atmospheric reanalysis data. Daily SAT anomaly and duration time are used in order to defi ne SAT anomaly cases. Diff erences with regard to the circulation anomalies over the Ural Mountains and the upstream North Atlantic area are evident. It is found that the colder than normal SAT is caused by the enhanced Ural high and associated southward fl ow over Northwest China. Time-lagged composites reveal possible connections between the SAT anomalies and the diff erent development phases of the North Atlantic Oscillation (NAO). The Ural highs tend to be strengthened during the negative phase of NAO (NAO–) to Atlantic ridge transition, which are closely related to the downstream-propagating Rossby wave activity. The opposite circulation patterns are observed in the warm SAT cases. A cyclonic circulation anomaly is distinctly enhanced over the Urals during the positive phase of NAO (NAO+) to Scandinavian blocking transition, which would cause warmer SAT over Northwest China. Further analyses suggest that the intensifi ed zonal wind over North Atlantic would favor the NAO–to Atlantic ridge transition, while the weakened zonal wind may be responsible for the transition between NAO+and Scandinavian blocking.

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

    International Nuclear Information System (INIS)

    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

  7. Water use measurement by non-irrigatedTamarix ramosissimain arid regions of Northwest China

    Institute of Scientific and Technical Information of China (English)

    Shuang Li; HongLang Xiao; YiBen Cheng; Fang Wang

    2015-01-01

    Tamarix ramosissima Ledeb. is a typical hardy desert plant growing in arid regions of Northwest China. Sap flow in stems ofT. ramosissima plants were measured continuously to determine the diurnal and seasonal variations of sap flow and to understand the water requirements of this species and the response of sap flow to meteorological factors. This article compared the sap flow rate measured by the heat balance method with the transpiration rate measured by rapid weighing, and validated that heat balance sap flow gauges were reliable for monitoring transpiration. The influence of meteorological factors on stem sap flow during the growing season was: solar radiation > vapor pressure deficit > air temperature > rela-tive humidity > wind speed. Bidirectional sap flows occurred at night, and negative sap flow generally corresponded to high atmospheric humidity. The average error in predicted sap flow rate ranged from−0.78% to 14.00% from June to September and for transpiration the average error was 8.19%. Therefore, based on the functional equations between sap flow and meteorological factors as well as sapwood area, transpiration of an individual plant, and even the stand-level transpiration, can be estimated accurately through extrapolation.

  8. Natural radioactivity in reservoir sediment near an industrial park of northwest China.

    Science.gov (United States)

    Lu, Xinwei; Pan, Huiyun; Ren, Chunhui; Yang, Linna

    2016-06-01

    The activity concentration of natural radionuclides in the sediment of a reservoir near an industrial park of northwest China was determined using gamma ray spectrometry. The activity concentrations of (226)Ra, (232)Th and (40)K in the investigated samples range from 30.2 to 37.5, 56.5 to 79.8 and 785.6 to 940.3 Bq kg(-1) with an average of 33.2, 71.8 and 866.2 Bq kg(-1), respectively, which are higher than the corresponding activity concentrations in the control sample. Radium equivalent activity, external hazard index, internal hazard index, indoor air absorbed dose rate and annual effective dose rate were calculated to assess the radiation hazards associated with the use of this sediment in the construction of dwellings. It was concluded that the radiation levels in the reservoir sediment do not give rise to radiological health concerns and the sediment can be safely used in the construction of buildings. PMID:27122204

  9. Effect of Dust Deposition on Stomatal Conductance and Leaf Temperature of Cotton in Northwest China

    Directory of Open Access Journals (Sweden)

    Shamaila Zia-Khan

    2014-12-01

    Full Text Available The Xinjiang Region in Northwest China is known as the “dust center” of the Eurasian mainland. Dust on the leaf surface affects overall plant development. While emphasis was on studying the impacts of industrial dust particles on crop development, the effect of natural dust deposition on the physiological parameters of cotton had not been studied before. The objective of this study was to examine the effects of dust deposits on cotton leaves and to estimate their impact on crop development and yield. For this purpose, an experiment was set up having two treatments and a control. In Treatment 1, cotton leaves were cleaned with water at three-day intervals or after a natural dust fall. In Treatment 2, 100 g·m−2 of dust was applied at 10-day intervals. The control received neither additional dust nor cleaning. In all of the treatments, stomatal conductance, leaf temperature, biomass and yield were measured. The results show a 28% reduction in yield and 30% reduction in stomatal conductance of the dust treatment compared to the control treatment. This indicates blocking of the stomata on the top of the leaf surface. In addition, the canopy temperature of the dust-applied leaves was always higher than the control and treatment.

  10. [Effects of thinning intensity on Pinus tabulaeformis plantation in Huanglong Mountain, Northwest China: a comprehensive evaluation].

    Science.gov (United States)

    Gao, Yun-Chang; Zhang, Wen-Hui; He, Jing-Feng; Wang, Jin-Tang

    2013-05-01

    A sampling plot investigation was conducted on the seedling regeneration, stand growth, species diversity, and soil characteristics in a Pinus tabulaeformis plantation in Huanglong Mountain on the Loess Plateau of Northwest China after 7 years of close-to-natural management thinning 15% (light thinning), 30% (medium thinning), and 45% (heavy thinning), with the effect of different thinning intensities evaluated. With the increase of thinning intensity, the amount and growth indices of 1-7 years old P. tabulaeformis seedlings increased, but the mean annual increments of the growth indices decreased after an initial increase, with the maximum under medium thinning. As compared with the control (un-thinned plantation), the individual volume under light, medium, and heavy thinning was increased by 20.9%, 32.1% and 52.6%, the volume per hm2 decreased by 4.4%, 15.1%, and 25.3%, and the mean annual growth rate of volume increased by 28.6%, 46.2% and 82.0%, respectively. The species diversity and soil characteristics were improved under thinning, with the order of heavy thinning > medium thinning > light thinning > un-thinning. In this study, 45% thinning was most suitable to the management of P. tabulaeformis plantation in Huanglong Mountain. PMID:24015549

  11. Geologic Mapping Investigations of the Northwest Rim of Hellas Basin, Mars

    Science.gov (United States)

    Crown, David A.; Bleamaster, Leslie F., III; Mest, Scott C.; Mustard, John F.

    2009-01-01

    The Hellas impact basin, spanning 2000+ km in the cratered highlands, is the largest well-preserved impact structure on Mars and its deepest depositional sink. The Hellas region is significant for evaluating Mars hydrogeologic and climate histories, given the nature, diversity, and range in ages of potential water- and ice-related landforms [e.g., 1-2], including possible paleolakes on the basin floor [2-4]. The circum-Hellas highlands are of special interest given recent studies of potential localized fluvial/lacustrine systems [2, 5-17] and evidence for phyllosilicates around and within impact craters north of the basin [18-26].

  12. 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.

  13. Seismic Data from the Kane Basin, Northwest Greenland - Insight into a white spot on the map

    Science.gov (United States)

    Ehrhardt, Axel; Schnabel, Michael; Damm, Volkmar

    2013-04-01

    The opening history of the Baffin Bay and the possible extent of oceanic crust within the basin is a key question in order to reconstruct the plate tectonic development of the Arctic region. To contribute to the scientific discussion, a multi-component geophysical and geological survey was carried out in 2010 in the area of the Northern Baffin Bay. Because of the fortunate ice conditions we seized the chance to go to the Kane Basin, half way between the Baffin Bay in the South and the Lincoln Sea in the North, one of a series of basins that are aligned along the Nares Strait. In addition the unclear situation within the Baffin Bay the Nares Strait is one of the most disputed areas in the Arctic. As the opening of the Baffin Bay and the formation of oceanic crust must have been compensated somewhere between Greenland and Ellesmere Island a transform fault was proposed. However, in particular land geological data does not support this thesis and let assume moreover that no lateral displacement occurred between Greenland and Ellesmere Island. In order to shed some more light onto the potential transform fault (the Wegener Fault) two reflection seismic lines were shot within the eastern Kane Basin supported by sonobuoys. Furthermore, magnetic and gravity data is acquired. This paper presents first insight into the eastern side of the Kane Basin. The eastern Kane Basin is characterized by a deeper rim and a more shallow central part of the basin. The term basin is probably misleading as most of it is floored by Proterozoic crust without any sedimentary beds on top of it. Only in the western part of the Kane Basin a sedimentary infill can be recorded which terminates with an erosional truncation on to the seafloor. The significant amount of sediments and debris that is washed into the Kane Basin by rivers and glaciers is transported to the Baffin Bay Fan by the considerably strong N-S current through the Nares Strait. A pull-apart development of the Kane Basin can't be

  14. Geological conditions of coal and gas(oil)-bearing basins in China

    Institute of Scientific and Technical Information of China (English)

    WANG; Tingbin

    2005-01-01

    There are various types of coal basins in China. Indosinian movement can be regarded as their evolutionary limit, and the basins can be divided into two developmental stages, three structural patterns and two sedimentary environments. However, only those coal measure strata that have been deeply buried in the earth are possible to be converted into coal and gas (oil)-bearing basins. Among which, only part of the coal measures possess the essential geological conditions to the formation of commercial humic oil. However, humic gas will be the major exploration target for natural gas in China. Among various coal basins, foreland basins have the best prospect for humic gas. Rift (faulted) basins accumulate the most abundance of humic gas, and are most favorable to generate humic oil. Craton basins have relatively low abundance of humic gas, but the evolution is rather great. The three kinds of coal basins mentioned above constitute China's three primary accumulation areas of humic gas: western, central and offshore areas. The major basins for humic gas field exploration include Tarim, Ordos, Sichuan, East China Sea and Yingqiong basins.

  15. Modern pollen rain in the Lake Qinghai basin, China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Lake Qinghai is the largest inland brackish lake in China and lies within the NE Tibetan Plateau. Our study shows that pollen assemblages in each vegetation belt are significantly correlated with the vegetation types of this area. Among the herbaceous and shrubby pollen assemblages, Artemisia is over-represented, while Poaceae, Cyperaceae and Polygonaceae are under-represented. Artemisia/ Chenopodiaceae (A/C) ratios with the regional vegetation characteristic can be used as a proper index to reconstruct the history of vegetation and climate in Lake Qinghai basin. Modern pollen in the lake mainly comes from the nearby vegetation, controlled by the directions and velocity of the wind. The distribution of modern pollen in Lake Qinghai tends to be similar in most part of the lake. The difference of pollen sedimentation process in the lake can be potentially influenced by the focusing function of the lake, river streams, and lake current.

  16. Integrated prediction based on GIS for sandstone-type uranium deposits in the northwest of Ordos Basin

    International Nuclear Information System (INIS)

    The integrated prediction model of sandstone-type uranium deposits and its integrated evaluation methods as well as flow of the work based on GIS are studied. A software for extracting metallogenic information is also developed. A multi-source exploring information database is established in the northwest of Ordos Basin, and an integrated digital mineral deposit prospecting model of sandstone-type uranium deposits is designed based on GIS. The authors have completed metallogenic information extraction and integrated evaluation of sandstone-type uranium deposits based on GIS in the study area. Research results prove that the integrated prediction of sandstone-type uranium deposits based on GIS may further delineate prospective target areas rapidly and improve the predictive precision. (authors)

  17. 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

  18. Cenozoic Tectono-stratigraphic sequences of the Shelf Rift Basin, East China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Armentrout, J.M.; Prebish, M.; Cunningham, A.C.; Echols, R.J.; Braithwaite, P.; Sarg, J.F. (Mobil Oil Corp., Dallas, TX (United States)); Norris, J.W.; Letsch, D.K.; Bracken, B.B.; Denison, C.N. (Chevron Overseas Petroleum Inc., San Ramon, CA (United States))

    1994-07-01

    The Tertiary section of the Jiaojiang, Qiantang, and Fushi depressions of the East China Sea Basin consists of at least eight rift-related depositional sequences identified seismically by regional onlap and truncation surfaces. Delineation of these sequences is based on interpretation of multifold seismic reflection profile data calibrated with several wells, including the Wenzhou 6-1-1 well. Upper Cretaceous( ) to Eocene synrift graben-restricted strata consist of two tectonically enhanced unconformity bounded sequences as evidenced by large angular discontinuities between each sequence. Discontinuous inclined-reflection seismic facies adjacent to the hanging wall correlate with nonmarine conglomeratic sandstone and are interpreted as possible alluvial fan facies. High-amplitude parallel reflections within the graben axes correlate with coaly siltstone strata and are interpreted as coastal plain and possibly lacustrine facies with source rock potential. Clinoform seismic facies prograding from the northwest footwall correlate with nonmarine to marginal marine conglomerate, sandstone, and siltstone, and are interpreted as possible delta or fan-delta facies with reservoir potential.

  19. Changes in precipitation and temperature in Xiangjiang River Basin, China

    Science.gov (United States)

    Ma, Chong; Pan, Suli; Wang, Guoqing; Liao, Yufang; Xu, Yue-Ping

    2016-02-01

    Global warming brings a huge challenge to society and human being. Understanding historic and future potential climate change will be beneficial to regional crop, forest, and water management. This study aims to analyze the precipitation and temperature changes in the historic period and future period 2021-2050 in the Xiangjiang River Basin, China. The Mann-Kendall rank test for trend and change point analysis was used to analyze the changes in trend and magnitude based on historic precipitation and temperature time series. Four global climate models (GCMs) and a statistical downscaling approach, LARS-WG, were used to estimate future precipitation and temperature under RCP4.5. The results show that annual precipitation in the basin is increasing, although not significant, and will probably continue to increase in the future on the basis of ensemble projections of four GCMs. Temperature is increasing in a significant way and all GCMs projected continuous temperature increase in the future. There will be more extreme events in the future, including both extreme precipitation and temperature.

  20. Typical basin-fill sequences and basin migration in Yanshan, North China--Response to Mesozoic tectonic transition

    Institute of Scientific and Technical Information of China (English)

    LI; Zhong; LIU; Shaofeng; ZHANG; Jinfang; WANG; Qingchen

    2004-01-01

    Basin-fill sequences of Mesozoic typical basins in the Yanshan area, North China may be divided into four phases, reflecting lithosphere tectonic evolution from flexure (T3), flexure with weak rifting (J1+2), tectonic transition (J3), and rifting (K). Except the first phase, the other three phases all start with lava and volcaniclastic rocks, and end with thick coarse clastic rocks and/or conglomerates, showing cyclic basin development rather than simple cyclic rift mechanism and disciplinary basin-stress change from extension to compression in each phase. Prototype basin analysis, based on basin-fill sequences, paleocurrent distribution and depositional systems, shows that single basin-strike and structural-line direction controlling basin development had evidently changed from east-west to northeast in Late Jurassic in the Yanshan area, although basin group still occurred in east-west zonal distribution. Till Early Cretaceous, main structural-line strike controlling basins just turned to northeast by north in the studied area.

  1. Spatial and temporal variability of water vapor pressure in the arid region of northwest China, during 1961-2011

    Science.gov (United States)

    Yao, Junqiang; Chen, Yaning; Yang, Qing

    2016-02-01

    This paper investigated the spatial and temporal variations of the water vapor pressure (WVP) of the arid region of northwest China (ARNC) from 1961 to 2011. The original daily temperature and relative humidity data were collected from 96 meteorological stations in the region and analyzed by a Mann-Kendall test and linear trend. The results showed that (1) the WVP possesses vertical zonality and longitude zonality, which decreased from the low to high with the elevation increasing, and the WVP changed obviously from the northwest and southeast to the middle of the ARNC. (2) WVP exhibited an abrupt increasing trend in most of the stations over the past 51 years; only four meteorological stations displayed upward trend in the ARNC. The WVP in the desert increased most rapidly, followed by the oasis and mountainous area. (3) The northwest of Xinjiang and northwest of the Hexi Corridor were sensitive to the water vapor change. Thus, further studies should be performed on the relations between the land use and cover and the water vapor change.

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

    Directory of Open Access Journals (Sweden)

    Feng Gao

    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

  3. Characteristics of Recent Horizontal Crustal Movement and Tectonic Deformation in the Northwest China Region

    Institute of Scientific and Technical Information of China (English)

    Liu Wenyi; Wang Shuangxu; Wang Wenping; Zhang Xiaoliang; Cui Duxin; Xue Fuping

    2006-01-01

    Making use of observation data of GPS in the Northwest China region and infrared distancemeasurements crossing the Qilian-Longshoushan fault zone up to 2004, aided by the least square collocation and inversion of negative dislocation model for the boundaries of elastic blocks and the singular force-source, the dynamic evolution features of deformation and strain fields before and after the Ms = 8. 1 earthquake on the west of Kunlun Mountains Pass,especially the recent tectonic deformation and stress field status three years after this earthquake are studied. The possible regions or segments of active blocks and their boundaries reflecting accumulation background of high strain energy of producing earthquakes over middle magnitude, are obtained, as well as the potential epicenter. The results show that after short-term relaxation and adjustment in the northern margin of Qinghai-Xizang (Tibet) block after the Ms = 8. 1 earthquake, the main control action of background field of northeastward pushing of Indian plate is now recovering. Moreover, the following regions are found to have the background of high strain energy accumulation. They are the middle segment of the northern Tianshan fault zone and its meeting region with the western segment, the middle and western segments of southern Tianshan fault zone and the meeting region with Western Kunlun fault zone, the middle segment of Altun fault, the middle-eastern segment of Qilianshan fault zone and its meeting region with Haiyuan fault, the meeting region of northern margin fault of west Qinling Range and the southeastward expanding line of Zhuanglanghe fault; The Linze and Haiyuan areas also see accumulation of strain energy to some degree.

  4. Evaluation of aeolian desertification from 1975 to 2010 and its causes in northwest Shanxi Province, China

    Science.gov (United States)

    Xue, Zhanjin; Qin, Zuodong; Li, Hongjian; Ding, Guangwei; Meng, Xianwen

    2013-08-01

    Efforts to control aeolian desertification in China have focused on the arid and semiarid regions. However, the direct dust emission rates, sediment characteristics and local-scale controls, as well as the measures needed to combat desertification, remain poorly understood in northwest Shanxi Province. Aeolian desertification is regarded as an obstacle to local sustainable socioeconomic development. This paper investigated changes in aeolian desertification between 1975 and 2010 on the northwestern Shanxi Plateau. In this study, remote sensing images were used to classify land suffering from aeolian desertification into four categories: light, moderate, severe, and extremely severe. To evaluate the evolution and status of aeolian desertification as well as its causes, we interpreted and analyzed Landsat multi-spectral scanner (MSS) image (acquired in 1975) and Landsat Thematic Mapper (TM) images (acquired in 1991, 2000, 2006, and 2010) as well as meteorological and socioeconomic data. Results revealed 11,866 km2, 13,362 km2, 14,051 km2, 13,613 km2, and 12,318 km2 of aeolian desertified land (ADL) in the above 5 periods, respectively. The spatial dynamics and patterns showed two stages: expansion during 1975-2000 at a rate of 87.37 km2 a- 1, and spatial transfer of affected areas during 2000-2010 with a net decrease of 173.27 km2 a- 1. During the evolution of aeolian desertification, areas of moderate ADL had the greatest dynamic response (11.45%). The factors controlling ADL dynamics were analyzed from the perspectives of two groups of factors: natural factors and human activities. Our results indicated that the climate-dominated natural factors contribute greatly to the occurrence and development of ADL. However, they are not the fundamental causes of its development. The human factors are the primary and direct driving forces responsible for the increase in ADL area. More thorough quantitative analysis, with more frequent remotely sensed data is needed to assess

  5. Variation Characteristics of Regional Synchronous Wind in Hami, Xinjiang of Northwest China

    Institute of Scientific and Technical Information of China (English)

    黄林宏; 宋丽莉; 李刚; 辛渝

    2015-01-01

    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 signifi cantly impact the electric power grid confi guration in large-scale wind power development. The correlation between duration and frequency of LWC/RWC/CWC is obtained. Major fi ndings 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 diff ers little between diff erent 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 signifi cantly diff erent. 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 fi tting 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.

  6. Geochemical Responses to Anthropogenic and Natural Influences in Ebinur Lake Sediments of Arid Northwest China

    Science.gov (United States)

    Wu, Jinglu; Abuduwaili, Jilili; Liu, Wen

    2016-01-01

    Geochemical concentrations were extracted for a short sediment core from Ebinur Lake, located in arid northwest China, and mathematical methods were used to demonstrate the complex pattern of the geochemical anomalies resulting from the temporal changes in natural and anthropogenic forces on the lake sediments. The first element assemblage (C1) (aluminum, potassium, iron, magnesium, beryllium, etc.) was predominantly terrigenous; among the assemblage, total phosphorus and titanium were generally consistent with aluminum except with regards to their surface sequences, which inferred the differences of source regions for terrigenous detrital material led to this change around ca. 2000AD. The second assemblage (C2) (calcium and strontium) was found to have a negative relationship with aluminum through a cluster analysis. The third assemblage (C3) included sodium and magnesium, which were influenced by the underwater lake environment and deposited in the Ebinur depression. The concentration ratio of C1/(C1+C2) was used as an indicator for denudation amount of detrital materials, which was supported by the values of magnetic susceptibility. The enrichment factors for heavy metals suggested that the influence of human activities on heavy-metal enrichment in Ebinur Lake region was not severe over the past century. Prior to the 1960s, geochemical indicators suggested a stable lacustrine environment with higher water levels. Beginning in the 1960s, high agricultural water demand resulted in rapid declines in lake water level, with subsequent increases of lake water salinity, as evidenced by enhanced sodium concentration in lake core sediments. During this period, anthropogenic activity also enhanced the intensity of weathering and the denudation of the Ebinur watershed. PMID:27176765

  7. 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.

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

    International Nuclear Information System (INIS)

    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 (Ta), maximum temperature (Tmax), and minimum temperature (Tmin) 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 Tmax and cultivated land proportions are the most significant. The trends in Ta, Tmax, and Tmin 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 Ta, Tmax, and Tmin 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)

  9. Nitrate Accumulation in Soil Profile of Dry Land Farming in Northwest China

    Institute of Scientific and Technical Information of China (English)

    FAN Jun; HAO Ming-De; SHAO Ming-An

    2003-01-01

    A long-term fertilizer experiment on dry land of the Loess Plateau, northwest China, has been conducted since 1984 to study the distribution and accumulation of NO3-N down to a depth of 400 cm in the profile of a coarse-textured dark loessial soil after continuous winter wheat cropping. Thirteen fertilizer treatments consisted of four levels of N and P applied alone or in combination. Annual N and P (P2O5) rates were 0,45, 90, 135 and 180 kg ha-1. After 15 successive cropping cycles, the soil samples were taken from each treatment for analysis of NO3-N concentration. The results showed that NO3-N distribution in the soil profile was quite different among the treatments. The application of fertilizer N alone resulted in higher NO3-N concentration in the soil profile than the combined application of N and P, showing that application of P could greatly reduce the NO3-N accumulation. With an annual application of 180 kg N ha-1 alone, a peak in NO3-N accumulation occurred at 140 cm soil depth, and the maximum NO3-N concentration in the soils was 67.92 mg kg-1. The amount of NO3-N accumulated in the soil profile decreased as the cumulative N uptake by the winter wheat increased. Application of a large amount of N resulted in lower N recoveries in winter wheat and greater NO3-N accumulation in soil profile. NO3-N did not enter underground water in the study region; therefore, there is no danger of underground water pollution. Amount of NO3-N accumulation can be predicted by an equation according to annual N and P rates based on the results of this experiment.

  10. Recent changes of precipitation in Gansu, Northwest China: An index-based analysis

    Science.gov (United States)

    Li, Cheng; Wang, Ranghui

    2016-04-01

    Monitoring variations in precipitation is important in detecting regional climate change and studying the hydrological cycle. An understanding of its dynamic characteristics will be valuable in the management of water resources in Northwest China. This study utilized daily precipitation data from 29 stations across Gansu spanning the years from 1960 to 2013; the data was used to investigate changes in precipitation by defining 21 precipitation-related indices. Trends were detected in the series of precipitation-related indices using the Mann-Kendall test. Primary results are as follows: (1) Decreasing trends in both the extreme precipitation and wet spell indices are indicative of a decrease in precipitation in southeastern Gansu, whereas the trends in the data indicate that northwestern Gansu has experienced an increase in precipitation; (2) decreasing trends in the annual number and length of dry spells with longer durations in northwestern Gansu also demonstrate that the precipitation frequency and intensity are increasing across this area; (3) by means of 24-month time scales, standardized precipitation index values, and principal component analysis, the Gansu can also be identified into two distinctive sub-regions, which predominantly show different variations of dryness/wetness during 1960-2013; and (4) the correlation analysis showed that the intensity of the western Pacific subtropical high possesses obvious effects on a number of precipitation indices in two subregions of Gansu. In addition, the Indian Ocean Dipole and Multivariate El Niño-Southern Oscillation (ENSO) index may also be important factors in the southeastern areas; in contrast, the impacts of large-scale climate indices on precipitation indices are less severe in northwestern Gansu.

  11. [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. PMID:26717708

  12. Geochemical Responses to Anthropogenic and Natural Influences in Ebinur Lake Sediments of Arid Northwest China.

    Directory of Open Access Journals (Sweden)

    Long Ma

    Full Text Available Geochemical concentrations were extracted for a short sediment core from Ebinur Lake, located in arid northwest China, and mathematical methods were used to demonstrate the complex pattern of the geochemical anomalies resulting from the temporal changes in natural and anthropogenic forces on the lake sediments. The first element assemblage (C1 (aluminum, potassium, iron, magnesium, beryllium, etc. was predominantly terrigenous; among the assemblage, total phosphorus and titanium were generally consistent with aluminum except with regards to their surface sequences, which inferred the differences of source regions for terrigenous detrital material led to this change around ca. 2000AD. The second assemblage (C2 (calcium and strontium was found to have a negative relationship with aluminum through a cluster analysis. The third assemblage (C3 included sodium and magnesium, which were influenced by the underwater lake environment and deposited in the Ebinur depression. The concentration ratio of C1/(C1+C2 was used as an indicator for denudation amount of detrital materials, which was supported by the values of magnetic susceptibility. The enrichment factors for heavy metals suggested that the influence of human activities on heavy-metal enrichment in Ebinur Lake region was not severe over the past century. Prior to the 1960s, geochemical indicators suggested a stable lacustrine environment with higher water levels. Beginning in the 1960s, high agricultural water demand resulted in rapid declines in lake water level, with subsequent increases of lake water salinity, as evidenced by enhanced sodium concentration in lake core sediments. During this period, anthropogenic activity also enhanced the intensity of weathering and the denudation of the Ebinur watershed.

  13. Paleoenvironmental reconstruction of the late Cenozoic Qaidam Basin, China

    Science.gov (United States)

    Zhang, C.; Wang, Y.; Li, Q.; Wang, X.; Deng, T.; Tseng, Z. J.; Takeuchi, G.; Xie, G.; Xu, Y.

    2011-12-01

    Reconstruction of paleoenvironments in the Tibetan region is important to understanding the linkage between tectonic force and climate change. Here we report new isotope data from the Qaidam Basin, China, which is located on the northeastern Tibetan Plateau, including stable C and O isotope analyses of a wide variety of late Cenozoic mammalian tooth enamel samples (including deer, giraffe, horse, rhino, and elephant), and O isotope compositions of phosphate (δ18Op) in fish bone samples. Mammalian tooth enamel δ13C values, when combined with fossil assemblage and other geological evidence, indicate that the Qaidam Basin was warmer and more humid during the late Miocene and early Pliocene, and that there was lush C3 vegetation with significant C4 components at that time, although the C4 plants were not consistently utilized. In contrast, the modern Qaidam Basin is dominated by C3 plants. Fish bone δ18Op values showed statistically significant enrichment from the Tuxi-Shengou-Naoge interval (late Miocene) to the Yahu interval (early Pliocene) and from the Yahu interval to the present day. This most likely reflects increases in the δ18O of lake water over time, as a result of increased aridification of the Qaidam Basin. Assuming that mammals drank exclusively from the lake, temperatures were calculated from average δ18Op values and average δ18Ow derived from large mammal tooth enamel δ18O. Temperatures were also estimated from δ18Op and δ18Ow estimated from co-ocurring large mammal tooth enamel δ18O. The temperature estimates were all lower than the average temperature of the modern Qinghai Lake surface water during the summer, and mostly too low to be reasonable, indicating that the fish and the large mammals were not in equilibrium with the same water. Assuming the relationship between salinity and δ18Ow observed for the modern Qinghai Lake and its surrounding lakes and ponds applied in the past, we calculated the paleosalinities of lake waters to be ~0 to

  14. Oil source analysis of Upper Tertiary Shawan Formation in Chepaizi area,in the northwest margin of Junggar basin

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Well che89,located in the Chepaizi area in the northwest margin of Junggar basin,acquires high production industrial oil flow,which is an important breakthrough in the exploration of the south foreland slope area of Junggar basin. The Chepaizi area is near two hydrocarbon generation depressions of Sikeshu and Shawan,which have sets of hydrocarbon source rock of Carboniferous to Jurassic as well as Upper Tertiary. Geological and geochemical parameters are proper for the accumulation of mixed source crude oil. Carbon isotope,group composition and biomarkers of crude oil in Upper Tertiary of well Che89 show that the features of crude oil in Upper Tertiary Shawan Formation are between that of Permian and Jurassic,some of them are similar to these two,and some are of difference,they should be the mixed source of Permian and Jurassic. Geochemical analysis and geological study show that sand extract of Lower Tertiary Wulunguhe Formation has the same source as the crude oil and sand extract of Upper Tertiary Shawan Formation,but they are not charged in the same period. Oil/gas of Wulunguhe Formation is charged before Upper Tertiary sedimentation,and suffered serious biodegradation and oxidation and rinsing,which provide a proof in another aspect that the crude oil of Upper Tertiary Shawan Formation of well Che89 is not from hydrocarbon source rock of Lower Tertiary.

  15. Chlorine isotopic geochemistry of salt lakes in the Qaidam Basin, China

    Digital Repository Service at National Institute of Oceanography (India)

    Liu, W.G.; Xiao, Y.K.; Wang, Q.Z.; Qi, H.P.; Wang, Y.H.; Zhou, Y.M.; Shirodkar, P.V.

    The isotopic compositions of chlorine in salt lake brine coexisting with halite, oil-field water and river water from the Qaidam Basin (Qinghai, China) have been examined using high-precision measurement of chlorine isotopes based on thermal...

  16. 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.

    2015-01-01

    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.

  17. Tectonic development of the Northwest Bonaparte Basin, Australia by using Digital Elevation Model (DEM)

    Science.gov (United States)

    Wahid, Ali; Salim, Ahmed Mohamed Ahmed; Ragab Gaafar, Gamal; Yusoff, AP Wan Ismail Wan

    2016-02-01

    The Bonaparte Basin consist of majorly offshore part is situated at Australia's NW continental margin, covers an area of approx. 270,000km2. Bonaparte Basin having a number of sub-basins and platform areas of Paleozoic and Mesozoic is structurally complex. This research established the geologic and geomorphologic studies using Digital Elevation Model (DEM) as a substitute approach in morphostructural analysis to unravel the geological complexities. Although DEMs have been in practice since 1990s, they still have not become common tool for mapping studies. The research work comprised of regional structural analysis with the help of integrated elevation data, satellite imageries, available open topograhic images and internal geological maps with interpreted seismic. The structural maps of the study area have been geo-referenced which further overlaid onto SRTM data and satellite images for combined interpretation which facilitate to attain Digital Elevation Model of the study area. The methodology adopts is to evaluate and redefine development of geodynamic processes involved in formation of Bonaparte Basin. The main objectives is to establish the geological histories by using digital elevation model. The research work will be useful to incorporate different tectonic events occurred at different Geological times in a digital elevation model. The integrated tectonic analysis of different digital data sets benefitted substantially from combining them into a common digital database. Whereas, the visualization software facilitates the overlay and combined interpretation of different data sets which is helpful to reveal hidden information not obvious or accessible otherwise for regional analysis.

  18. Palinspastic reconstruction and geological evolution of Permian residual marine basins bordering China and Mongolia

    Institute of Scientific and Technical Information of China (English)

    Gen-Yao Wu

    2014-01-01

    One main feature of the tectono-paleogeographic evolution of the southern branch of the Paleo-Asian Ocean was that there developed residual marine basins in former backarc/forearc regions after the disappearance of oceanic crust. The paper illustrates the viewpoint taking the evolution of Dalandzadgad and Solonker oceanic basins as examples. The Dalandzadgad ocean subducted southwards during the Silurian-Devonian, created an intra-oceanic arc and a backarc basin in southern Mongolia. In addition, a continent marginal arc formed along the national boundary between China and Mongolia, the south of which was a backarc basin. The oceanic basin closed and arc-arc (continent) collision occurred dur-ing the early Early Permian, followed by two residual marine basins developing in the former backarc regions, named the South Gobi Basin in southern Mongolia and the Guaizihu Basin in western Inner Mongolia. The Solonker ocean subducted southwards and ifnally disappeared during the early Middle Permian. Afterwards, two residual marine basins occurred in northern China, the Zhesi Basin being situated in the former backarc region and the Wujiatun Basin in the former forearc region. The late Middle Permian was the most optimum period for the de-veloping residual marine basins, when they covered a vast area. The basin evolution differenti-ated during the early Late Permian, with a general trend of uplift in the east and of subsidence in the west. The Upper Permian in the South Gobi Basin was characterized by coal-bearing strata hosting economically valuable coal ifelds. A transgression invaded westwards and the Chandmani-Bayanleg Basin was created in southwest Mongolia during the middle-late stage of the Late Permian. Correspondingly, the coal formation entered a lfourishing time, with thick coal beds and sedimentary interbeds. All of these basins, namely, both the marine and non-marine residual basins, reversed and closed by the end of Permian.

  19. Palinspastic reconstruction and geological evolution of Permian residual marine basins bordering China and Mongolia

    Institute of Scientific and Technical Information of China (English)

    Gen-Yao; Wu

    2014-01-01

    One main feature of the tectono-paleogeographic evolution of the southern branch of the Paleo-Asian Ocean was that there developed residual marine basins in former backarc/forearc regions after the disappearance of oceanic crust.The paper illustrates the viewpoint taking the evolution of Dalandzadgad and Solonker oceanic basins as examples.The Dalandzadgad ocean subducted southwards during the Silurian-Devonian,created an intra-oceanic arc and a backarc basin in southern Mongolia.In addition,a continent marginal arc formed along the national boundary between China and Mongolia,the south of which was a backarc basin.The oceanic basin closed and arc-arc(continent) collision occurred during the early Early Permian,followed by two residual marine basins developing in the former backarc regions,named the South Gobi Basin in southern Mongolia and the Guaizihu Basin in western Inner Mongolia.The Solonker ocean subducted southwards and finally disappeared during the early Middle Permian.Afterwards,two residual marine basins occurred in northern China,the Zhesi Basin being situated in the former backarc region and the Wujiatun Basin in the former forearc region.The late Middle Permian was the most optimum period for the developing residual marine basins,when they covered a vast area.The basin evolution differentiated during the early Late Permian,with a general trend of uplift in the east and of subsidence in the west.The Upper Permian in the South Gobi Basin was characterized by coal-bearing strata hosting economically valuable coal fields.A transgression invaded westwards and the Chandmani-Bayanleg Basin was created in southwest Mongolia during the middle-late stage of the Late Permian.Correspondingly,the coal formation entered a flourishing time,with thick coal beds and sedimentary interbeds.All of these basins,namely,both the marine and nonmarine residual basins,reversed and closed by the end of Permian.

  20. Understanding sedimentation in the Song Hong-Yinggehai Basin, South China Sea

    OpenAIRE

    Yan, Y.; Carter, A; Palk, C.; S. Brichau; Hu, X

    2011-01-01

    The Cenozoic Song Hong–Yinggehai Basin in the South China Sea contains a large volume of sediment that has been used in previous studies, together with regional geomorphology, to argue for the existence of a large palaeodrainage system that connected eastern Tibet with the South China Sea. To test this and to understand the significance of sediment volumes deposited in the Song Hong–Yinggehai Basin, this study compared erosion histories of source regions with sediment volumes deposited during...

  1. Distribution of the East China Sea continental shelf basins and depths of magnetic sources

    OpenAIRE

    Lin, Jing-yi; Sibuet, Jean-claude; Hsu, S.

    2005-01-01

    The acoustic basement map of the East China Sea, established by the Shanghai Offshore Petroleum Bureau with all available industry seismic data, shows the existence of a 30-km-wide, 10-km-deep basin, that we named the Ho Basin. The Ho Basin belongs to a series of elongated deep basins extending over 600 km east of the Taiwan-Sinzi Ridge and flanked to the East by a ridge named the Longwan Ridge in its northern part. This new system of basin and ridge was probably formed during middle Miocene,...

  2. Distribution of major hydrocarbon source rocks in the major oil-gas-bearing basins in China

    Institute of Scientific and Technical Information of China (English)

    LIU Luofu; ZHAO Suping; CHEN Lixin; HUO Hong

    2005-01-01

    The distribution characteristics of major hydrocarbon source rocks in the major oil-gas-bearing basins in China were discussed in this paper, and differences between the East and the West basins in tectonic setting, age, lithology, sedimentary environment, and hydrocarbon generation feature and potential were also studied. Considering the Lüliang Mountains-Dalou Mountains as the boundary, source rocks in the East basins are distributed mainly in three NNE-trend subsiding belts, and those in the West basins are distributed in the north and south of the Tianshan Mountains and Qilian Mountains. They are mainly NWW trending and can be divided into four basin groups.

  3. Moho structure of the South China Sea basin and the surrounding from constrained 3-D gravity inversion

    Science.gov (United States)

    Zhaocai, W.; Jinyao, G.

    2014-12-01

    We have obtained the Moho depth of the South China Sea basin using gravity data with the 191 control points from seismic data and sonobuoys. To obtain the residual mantle Bouguer anomaly (RMBA), we deducted the anomaly from lateral changes in bathymetry or topography, the gravity anomaly due to changes in sediment thickness and density from the free air anomaly firstly, and then corrected the lithosphere thermal gravity anomaly from the rifted margin to the spread ridge. According to the relationship between the control points and RMBA, we calculated the initial Moho depth, from which, we done an iterative cycle of gravity inversion to predict the final Moho depth and crustal thickness. To calculate the lithosphere thermal gravity anomaly, we defined a critical thinning factor for the initiation of oceanic crust production, and a maximum oceanic crustal thickness; for this study area, values of 0.5 and 9 km were used respectively, consistent with the Moho depth of 20km and 14km respectively, with the initial thickness of continental crust of 32km. The RMS(root mean square) difference with the control points is 1.54km. Over most of the South China Sea basin, the Moho depth is 11 and 13km, the crustal thickness is 5-8km. The Moho depth of the Northwest sub basin has values between 12 and 13km, the crustal thickness is mostly ~7km. The NW trending fault divides obviously the extinct spreading centers of the East and southwest sub basin. Meanwhile, on the north side of the two sub basin extinct spreading centers, the crustal thickness is slightly thicker 1km than the south. The ocean-continent transition (OCT) is enclosed by the 14km and 20km Moho depth contour. At the East sub basin, the OCT shows asymmetry, and is broader and longer on the northern margin than the southern margin. One of the most noticeable characteristics in the northeastern margin of the OCT is that the crustal thickness is 10-16km. However, at the southwest sub basin, the OCT is symmetrical.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Zhang, Tianyi; Wang, Hesong

    2015-01-01

    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. PMID:25961563

  6. Morphological and biological investigation of two pioneer Ips bark beetles in natural spruce forests in Qinghai Province, northwest China

    Institute of Scientific and Technical Information of China (English)

    LIU Li; WU Jian; LUO You-qing; LI Zhen-yu; WANG Guo-cang; HAN Fu-zhong

    2008-01-01

    Bark beetle species in natural stands of spruce, Picea crassifolia (Kom.) were investigated in Maixiu Forest Park, Qinghai Province, northwest China, during 2005 and 2007. Two pioneer lps species, Ips nitidus Eggers and lps shangrila Cognato and Sun were found. L nitidus occurs naturally in northwest China. L shangrila is a new species in the world. In the past, it was confused with I. mannsfeldi Wachtl in China. The damage of these two Ips species has been very severe in Maixiu and the morphological and biological characteristics were studied. L nitidus starts to fly in early May and prefers the mid to lower part of the host tree to colonize as its habitat. L shangrila always infests from the top of the trunk, especially in branches larger than 3 em in diameter in the crowns and sometimes even colonizes entire young trees. The two Ips species are the most destructive secondary bark beetles on P. crassifolia and always cause mortality of trees by their cooperation.

  7. Dongxiang Muslim women as ‘boundary subjects’: Reflections on gender and identity in the borderland areas of northwest China

    Directory of Open Access Journals (Sweden)

    Man, Ke

    2010-04-01

    Full Text Available With the highest female illiteracy rate in China (2000 national census, the Dongxiang Muslim community in northwest China shows the most striking male-female gender hierarchy among all Muslim nationalities in northwest China. This paper explains how local Islamic culture – jiaopai and menhuan -- and the distinction made between Dongxiang (minority and Han (majority identity devalue women and restrict their mobility. Specifically, Dongxiang people are divided into different Islamic sects (jiaopai and menhuan or jiaomen, such as Beizhuang, Humen, and Santai. Most of them hold to their own sects and demonstrate negative evaluation of other jiaomen, so inter-jiaomen marriages are always forbidden. Women are the symbolic carrier of the jiaomen to which they belong, as can be seen in the distinctive head scarf (gaitou women wear which signifies a given religious membership. To prevent their women from marrying out of the jiaomen and ensure integrity of the menhuan population, Dongxiang men constrain their women’s mobility. Gender also marks the ethnic boundary between Han Chinese (majority and Dongxiang Muslim (minority relations, legitimized by patriarchal interpretations of the holy scriptures which restrict women in the name of Allah. The paper argues that contemporary gender hierarchies in the Dongxiang community are not primarily moulded by Islam but by the cultural practices of a patriarchal society.

  8. Molecular Epidemiological Investigation of Porcine kobuvirus and Its Coinfection Rate with PEDV and SaV in Northwest China.

    Science.gov (United States)

    Wang, Chen; Lan, Xi; Yang, Bin

    2016-01-01

    Porcine kobuvirus (PKV) has circulated throughout China in recent years. Although many studies have detected it throughout the world, its molecular epidemiology has not been characterized in northwest China. To understand its prevalence, 203 fecal samples were collected from different regions of Gansu Province and tested with reverse transcription-polymerase chain reaction. In this study, we tested these samples for PKV, porcine epidemic diarrhea virus (PEDV), and sapovirus and analyzed the amplified 2C gene fragments of PKV. Overall, 126 (62.1%) samples were positive for PKV. Of the 74 piglets samples among the 203 fecal samples, 65 (87.8%) were positive for PKV. PKV infection was often accompanied by PEDV, but the relationship between the two viruses must be confirmed. A phylogenetic analysis indicated that the PKV strains isolated from the same regions clustered on the same branches. This investigation shows that PKV infections are highly prevalent in pigs in northwest China, especially in piglets with symptoms of diarrhea. PMID:27294133

  9. Molecular Epidemiological Investigation of Porcine kobuvirus and Its Coinfection Rate with PEDV and SaV in Northwest China

    Directory of Open Access Journals (Sweden)

    Chen Wang

    2016-01-01

    Full Text Available Porcine kobuvirus (PKV has circulated throughout China in recent years. Although many studies have detected it throughout the world, its molecular epidemiology has not been characterized in northwest China. To understand its prevalence, 203 fecal samples were collected from different regions of Gansu Province and tested with reverse transcription-polymerase chain reaction. In this study, we tested these samples for PKV, porcine epidemic diarrhea virus (PEDV, and sapovirus and analyzed the amplified 2C gene fragments of PKV. Overall, 126 (62.1% samples were positive for PKV. Of the 74 piglets samples among the 203 fecal samples, 65 (87.8% were positive for PKV. PKV infection was often accompanied by PEDV, but the relationship between the two viruses must be confirmed. A phylogenetic analysis indicated that the PKV strains isolated from the same regions clustered on the same branches. This investigation shows that PKV infections are highly prevalent in pigs in northwest China, especially in piglets with symptoms of diarrhea.

  10. Modeling Ecohydrological Processes and Spatial Patterns in the Upper Heihe Basin in China

    OpenAIRE

    Bing Gao; Yue Qin; Yuhan Wang; Dawen Yang; Yuanrun Zheng

    2015-01-01

    The Heihe River is the second largest inland basin in China; runoff in the upper reach greatly affects the socio-economic development in the downstream area. The relationship between spatial vegetation patterns and catchment hydrological processes in the upper Heihe basin has remained unclear to date. In this study, a distributed ecohydrological model is developed to simulate the hydrological processes with vegetation dynamics in the upper Heihe basin. The model is validated by hydrological o...

  11. Abiogenic hydrocarbons in commercial gases from the Songliao Basin, China

    Institute of Scientific and Technical Information of China (English)

    WANG XianBin; WANG LianSheng; LIU ChunXue; YAN Hong; LI LiWu; ZHOU XiaoFeng; WANG YongLi; YANG Hui; WANG Guang; GUO ZhanQian; TUO JinCai; GUO HongYan; LI ZhenXi; ZHUO ShengGuang; JIANG HongLiang; ZENG LongWei; ZHANG MingJie

    2009-01-01

    This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mecha-nisms and from different sources in nature. It is demonstrated that the biodegradation or thermode-gradation of complex high-molecule sedimentary organic material can form microbial gas or ther-mogenic gas. The δ13C1 value ranges from -110‰ to -50‰ for microbial gases but from -51‰ to -35‰ (even heavier) for thermogenic gases. Controlled by the kinetic isotope fractionation, both microbial and thermogenic gases have δ13C and δD values characterized by normal distribution, i.e. δ13C1 δ13C2> δ13C3> δ13C4 and δDCH4<δDC2H6< δDC3H8< δDC4H10. The δ13C values and δD values are negatively correlated. Natural gases from 26 commercial gas wells distributed in the Xujiaweizi and Yingshan-Miaotaizi faulted de-pressions in the Songliao Basin, China, show δ13C1 values ranging from -30.5‰. to -16.7‰, with a very narrow δD range between -203‰--196‰. These gases are characterized by a reverse distribution of δ13C values but a normal distribution of δD values, and a negative correlation between their δ13C and δD values, indicating an abiological origin. The present study has revealed that abiogenic hydrocar-bons not only exist in nature but also can make significant contribution to commercial gas reserviors. It is estimated that the reserve volume of alkane gases with abiogenic characteristics in these 26 gas wells in the Songliao Basin is over 500×108 m3, The prospecting practice in the Songliao Basin has demonstrated that abiogenic alkane gases are of a promising resource, and it provides an example for the investigation of and search for abiogenic commercial natural gases worldwide.

  12. Abiogenic hydrocarbons in commercial gases from the Songliao Basin, China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper discusses the kinetic fractionation, composition and distribution characteristics of carbon and hydrogen isotopes for various alkane gases formed in different environments, by different mecha- nisms and from different sources in nature. It is demonstrated that the biodegradation or thermode- gradation of complex high-molecule sedimentary organic material can form microbial gas or thermogenic gas. The δ 13C1 value ranges from -110‰ to -50‰ for microbial gases but from -50‰ to -35‰ (even heavier) for thermogenic gases. Controlled by the kinetic isotope fractionation, both microbial and thermogenic gases have δ 13C and δ D values characterized by normal distribution, i.e. δ 13C1< δ 13C2< δ 13C3< δ 13C4 and δ DCH4< δ DC2H6< δ DC3H8<δ DC4H10, and by a positive correlation between the δ 13C and δ D values. Simple carbonbearing molecules (CH4, CO and CO2) can form abiogenic alkane gases via polymerization in the abiological chemical process in nature, with δ 13C1 heavier than -30‰. Moreover, controlled by the kinetic isotope fractionation, abiogenic alkane gases are characterized by a reverse distribution of δ 13C values and a normal trend of δ D values, namely δ 13C1> δ 13C2> δ 13C3> δ 13C4 and δ DCH4<δ DC2H6< δ DC3H8< δ DC4H10. The δ 13C values and δ D values are negatively correlated. Natural gases from 26 commercial gas wells distributed in the Xujiaweizi and Yingshan-Miaotaizi faulted depressions in the Songliao Basin, China, show δ13C1 values ranging from -30.5‰ to -16.7‰ with a very narrow δ D range between -203‰―-196‰. These gases are characterized by a reverse distribution of δ 13C values but a normal distribution of δ D values, and a negative correlation between their δ 13C and δ D values, indicating an abiological origin. The present study has revealed that abiogenic hydrocarbons not only exist in nature but also can make significant contribution to commercial gas reserviors. It is estimated that

  13. Seed weight and germination behavior of the submerged plant Potamogeton pectinatus in the arid zone of northwest China

    OpenAIRE

    Li, Zhongqiang; Lu, Wei; YANG, Lei; Kong, Xianghong; Deng, Xuwei

    2015-01-01

    Variation in seed weight is common within and among plant species, but few studies have attempted to document the pattern of seed weight and germination attributes for aquatic macrophytes at a large scale. This study examined within-species variation in seed weight and germination attributes and the effects of environmental factors on seed traits of the submerged plant Potamogeton pectinatus in the arid zone of northwest China. Our results showed that the average seed weight was 0.24 g per 10...

  14. Origin and Distribution of Hydrogen Sulfide in Oil-Bearing Basins, China

    Institute of Scientific and Technical Information of China (English)

    ZHU Guangyou; ZHANG Shuichang; LIANG Yingbo

    2009-01-01

    The concentration of hydrogen sulfide gas (H_2S) varies greatly in the oil-bearing basins of China, from zero to 90%. At present, oil and gas reservoirs with high H_2S concentration have been discovered in three basins, viz. the Bohai Bay Basin, Sichuan Basin and the Tarim Basin, whereas natural gas with low H_2S concentration has been found in the Ordos Basin, the Songiiao Basin and the Junggar Basin. Studies suggest that in China H_2S origin types are very complex. In the carbonate reservoir of the Sichuan Basin, the Ordos Basin and the Tarim Basin, as well as the carbonate-dominated reservoir in the Luojia area of the Jiyang depression in the Bohai Bay Basin, Wumaying areas of the Huanghua depression, and Zhaolanzhuang areas of the Jizhong depression, the H_2S is of Thermochemical Sulfate Reduction (TSR) origin. The H_2S is of Bacterial Sulphate Reduction (BSR) origin deduced from the waterflooding operation in the Changheng Oiifieid (placanticline oil fields) in the Songliao Basin. H_2S originates from thermal decomposition of sulfur-bearing crude oil in the heavy oil area in the Junggar Basin and in the Liaohe heavy oil steam pilot area in the western depression of the Bohai Bay Basin. The origin types are most complex, including TSR and thermal decomposition of sulfcompounds among other combinations of causes. Various methods have been tried to identify the origin mechanism and to predict the distribution of H_2S. The origin identification methods for H_2S mainly comprise sulfur and carbon isotopes, reservoir petrology, particular biomarkers, and petroleum geology integrated technologies; using a combination of these applications can allow the accurate identification of the origins of H_2S. The prediction technologies for primary and secondary origin of H_2S have been set up separately.

  15. Rapid population collapse of the critically endangered Valencia letourneuxi in Kalamas basin of Northwest Greece

    Directory of Open Access Journals (Sweden)

    Ioannis Paschos

    2010-07-01

    Full Text Available In order to assess the current status of the critically endangered Valencia letourneuxi in Kalamas River basin, an extensive field survey including twelve sampling stations was undertaken using back-pack electrofishing device, D-shaped frame net and small mesh size nets in October 2008. In total, 552 fish specimens were collected, belonging to ten freshwater fish species, plus mullets (collectively grouped as Mugil spp.. V. letourneuxi was found at one station (Anakoli ditch (8.3% of sampling stations, at very low relative density (0.95%, where it co-occurred with the loach Cobitis hellenica, the goby Economidichthys pygmaeus and the introduced Eastern mosquitofish Gambusia holbrooki, with the last at very high relative densities. Moreover, water samples from selected stations were phasmatophotometrically analysed for ΝΗ3-Ν, ΝΗ3, ΝΗ4, ΝΟ2-Ν, ΝΟ2, ΝaΝΟ2, NO3-N, NO3, PO4, P and P2O5. Overall, V. letourneuxi was extirpated from one of its two previously known populations in this basin and its single surviving population was characterized by low local relative density and steep decline in relation to recent records (2005. Moreover, the presence at very high densities of the G. holbrooki as well as the increased eutrophication (due to high ammonia and phosphorus inputs in its highly modified habitat, suggest a rapid population collapse with significant risk of extirpation from Kalamas basin in the near future. The necessary conservation measures are outlined.

  16. Origin of Natural Gas in Kekeya Field, Tarim Basin, China

    Institute of Scientific and Technical Information of China (English)

    Hou Dujie; Xiao Zhongyao; Tang Youjun; Zhu Junzhang; Li Xianqing

    2004-01-01

    This paper is mainly concentrated on the geochemical characteristics and origin of gas of Kekeya field in the Tarim basin, NW China. This study shows that Permian mudstone is the main source rock of oil and gas. Based on the carbon isotopes of C1-C4, the carbon isotope of gas in Kekeya field is a little heavier than that in the typical marine-derived gas. The relationship between carbon isotopes of methane and ethane is coincident with Faber equation of gas derived from organic matter Ⅰ/Ⅱ. The majority of gas maturity is estimated, based on the formula, at 1.8 %-2.2 % besides K2 and K18 wells. In addition, the gas derived from 0.9 %-1.2 % Ro source rocks may also be mixture. 40Ar/36Ar and 3He/4He ratios from the gas samples also support the mixing process. Moreover, the gas in this region is mainly generated from more mature source rocks although the low mature gas exists.

  17. Precipitation variability assessment of northeast China: Songhua River basin

    Indian Academy of Sciences (India)

    Muhammad Imran Khan; Dong Liu; Qiang Fu; Muhammad Azmat; Mingjie Luo; Yuxiang Hu; Yongjia Zhang; Faiz M Abrar

    2016-07-01

    Variability in precipitation is critical for the management of water resources. In this study, the researchentropy base concept was applied to investigate spatial and temporal variability of the precipitationduring 1964–2013 in the Songhua River basin of Heilongjiang Province in China. Sample entropy wasapplied on precipitation data on a monthly, seasonally, annually, decade scale and the number of rainydays for each selected station. Intensity entropy and apportionment entropy were used to calculate thevariability over individual year and decade, respectively. Subsequently, Spearman’s Rho and Mann–Kendall tests were applied to observe for trends in the precipitation time series. The statistics of sampledisorder index showed that the precipitation during February (mean 1.09, max. 1.26 and min. 0.80),April (mean 1.12, max. 1.29 and min. 0.99) and July (mean 1.10, max. 1.20 and min. 0.98) contributedsignificantly higher than those of other months. Overall, the contribution of the winter season wasconsiderably high with a standard deviation of 0.10. The precipitation variability on decade basis wasobserved to increase from decade 1964–1973 and 1994–2003 with a mean value of decadal apportionmentdisorder index 0.023 and 0.053, respectively. In addition, the Mann–Kendall test value (1.90) showed asignificant positive trend only at the Shangzhi station.

  18. Geomorphic evidence of unrecognized Balapur fault segment in the southwest Kashmir basin of northwest Himalayas

    Science.gov (United States)

    Ahmad, Shabir; Alam, Akhtar; Ahmad, Bashir; Bhat, M. I.; Sultan Bhat, M.

    2015-12-01

    The Balapur fault (BF) is a high angle thrust fault (reverse), dipping ~ 60° NE, with an established length of ~ 40 km striking NW-SE of the Kashmir basin. However, geomorphic traces suggest that the strike of the BF propagates beyond what has been documented previously. The present investigation aims to identify the unrecognized segment of the BF in the SW of the Kashmir basin using hypsometric variability in longitudinal profiles (knickpoints/zones), followed by validation through stream gradient index (SL) calculations of the rivers draining the area. The longitudinal profiles of all the streams indicate prominent and consistent anomalies in the upper and mid-reaches even on the coarse resolution data (Survey of India topographic maps - 1:50,000/40 m, DEM-SRTM 90 m). The profile anomalies in the upper reaches (hard rock zone) of the streams may be attributed to lithological contacts, i.e., Panjal trap agglomeratic slate-shale-limestone. However, the river profile convex segments and course deflection specifically in the mid-reaches (soft rock zone) are most likely associated with recent tectonic activity. Geomorphic signatures suggest that these anomalies coincide with the strike of the recognized segment of the BF. Moreover, the SL values of each stream express a clear agreement with the anomalies shown by the long profiles of the rivers. Hence, we infer that the strike of the BF extends for a significant distance (~ 95 km) over the northeastern flank of the Pir Panjal range in the NW-SE direction.

  19. Water resources evolution and social development in Hai River basin, China

    Science.gov (United States)

    Peng, Dingzhi; You, Jinjun

    2010-05-01

    The Hai River basin is one of the three important bread baskets in China. As the rapid economy development in the basin, surface water reduction, groundwater overexploitation and water pollution had caused serious deterioration of the ecological environment. The rainfall, evaporation, surface water, groundwater, water quality, pollution sources, supply and demand of water resources were analyzed and the characteristic of water resources evolution was summarized in Hai River basin. Furthermore, the social and economic development and the relationship between water resources evolution and social development were discussed in the basin. It was found that the human activity is the first impact factor of water cycle in Hai River basin, and the climate change is the second. Finally, the attenuation of water resources in the basin was induced by the two factors together. For sustainable utilization of water resources in the Hai River basin, the unified management and optimal allocation of water resources should be strengthened and promoted.

  20. Distribution of the East China Sea continental shelf basins and depths of magnetic sources

    Science.gov (United States)

    Lin, J.-Y.; Sibuet, J.-C.; Hsu, S.-K.

    2005-11-01

    The acoustic basement map of the East China Sea, established by the Shanghai Offshore Petroleum Bureau with all available industry seismic data, shows the existence of a 30-km-wide, 10-km-deep basin, that we named the Ho Basin. The Ho Basin belongs to a series of elongated deep basins extending over 600 km east of the Taiwan-Sinzi Ridge and flanked to the East by a ridge named the Longwan Ridge in its northern part. This new system of basin and ridge was probably formed during middle Miocene, sometimes in between rifting episodes occurring in the Taipei Basin and Okinawa Trough. It complements the already defined system of five belts of backarc basins and associated arc volcanic ridges in the East China Sea, which are progressively younger from the Mainland China shoreline (late Cretaceous/early Tertiary) to the Okinawa Trough (Present). In order to determine the crustal thickness beneath the East China Sea continental shelf, we used a power spectrum method to calculate the depth of the top (Zt) and the centroid (Zo) of the magnetic basement by fitting a straight line through the high- and low-wave number portions of the power spectrum, respectively. Then, the depth of the base (Zb)is estimated from Zt and Zo. After optimizing the size of the data squares, we demonstrate that, except for basins more than 10 km deep, Zt corresponds to the basement depths and Zb, the depth of the Curie point, to the Moho depth. As wide-angle reflection and refraction data are scarce in the East China Sea, this method provides a way to characterize the crustal thickness of the East China Sea and to compute the theoretical heat flow values.

  1. Natural gas origins of large and medium-scale gas fields in China sedimentary basins

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    China sedimentary basins present abundant natural gas resource thanks to its unique geological settings.Marine highly-matured hydrocarbon source rocks,widespread coal-measure strata and low temperature Quaternary saline strata,etc.,indicate the wide foreground of China natural gas resources. Up to now,most of the petroliferous basins have been discovered to have wholesale natural gas accumulation from Precambrian,Paleozoic,Mesozoic to Cenozoic in the east,the central,the west and the coast of China.These large and medium-scale gas reservoirs are mainly composed of hydrocarbon gas with big dry coefficient,tiny non-hydrocarbon,wide carbon isotope distribution and varying origin types,the hydrocarbon gas includes coal-formed gas,oil-formed gas,biogenic gas and inorganic gas, etc.Coal-formed gas is the main type of China natural gas resources,in particular several explored large-scale gas fields(>100 billion cubic meter)of Kela 2,Sulige and Daniudi,etc.,they all belong to coal-formed gas fields or the gas fields consisting mostly of coal-formed gas.Oil-formed gas is also abundant in China marine basins,for example marine natural gas of Sichuan Basin generated from crude oil cracking gas.Primary and secondary biogenic gas fields were discovered respectively in the Qaidam Basin and Western Slope of Songliao Basin.In addition,inorganic gases are mainly distributed in the eastern China,in particular the Songliao Basin with abundant carbon dioxide accumulation,indicating that the eastern China present large exploration potential of inorganic gas.

  2. Occurrence of soluble salts and moisture in the unsaturated zone and groundwater hydrochemistry along the middle and lower reaches of the Heihe River in northwest China

    Science.gov (United States)

    Zhou, Xun; Fang, Bin; Wan, Li; Cao, Wenbing; Wu, Shengjun; Feng, Weidong

    2006-08-01

    Deforestation, over-development of water resources and population growth have contributed to degeneration of vegetation in the Heihe River Basin in northwest China. Salts and water contents are the most important factors affecting the growth of vegetation in this arid area. This study was conducted to determine soluble salt levels of soils in the unsaturated zone and the hydrochemistry of groundwater at 14 sites in this region. Concentrations of soluble ions in the soils deceased with depth. Soil ion contents increased at depths below the root system of native plants. Sulfate was the dominant anion in both the unsaturated zone and the groundwater. Total dissolved solids (TDS) in groundwater ranged from less than 1 g/L in the middle reaches of the watershed to about 10 g/L in the arid lower reaches. In the middle and upper reaches of the watershed, salinity in soil and groundwater decreased. Groundwater was highly variable in hydrochemistry. The lower reaches was predominated by SO4-Na•Mg and SO4-Mg•Na type water, whereas in the middle reaches groundwater is characterized by lower TDS and HCO3-dominated type water. Evapotranspiration is responsible for occurrence of the soluble salts in the soil profiles. Dissolution is the dominant chemical process in the middle reaches, whereas evapotranspiration prevails in the lower reaches of the Heihe River.

  3. Comparison of metallogenic conditions for sandstone-type uranium deposit between Erlian basin of China and sedimentary basins of Mongolia

    International Nuclear Information System (INIS)

    Based on the study of metallogenic background and basic metallogenic characteristics,this paper summarizes the main ore-controlling factors of sandstone-type uranium deposits in Erlian basin of China and basins in southeastern Mongolia with the theory of sandstone-type uranium metallogeny,and systematically analyses similarities and differences between the two areas. The general similarities of tectonic attribute, basin type and scale, uranium source, and tectonic evolution in both areas are proposed in this paper, and also their obvious differences in uranium-hosting strata, late tectonic activity and regional uranium mineralization occurrences, especially in tectonic activity and ore-controlling sedimentary system are proposed. The authors believe that the two areas have approximate uranium-productive potentialities, and propose the importence of prospecting 'Sumin-river model' sandstone-type uranium deposit in Erlian basin in the future. (authors)

  4. Ecosystem Services and Related Sustainable Management of River Oases along the Tarim River in Northwest China

    Science.gov (United States)

    Disse, M.; Keilholz, P.; Rumbaur, C.; Thevs, N.

    2011-12-01

    Within the Taklimakan Desert of Northwestern China, an area renowned for its extreme climate and vulnerable ecosystems, lies one of the largest inland rivers in the world, the Tarim River. Because the Tarim River is located in a remote area from the oceans, rainfall is extremely rare (less than 50 mm per year) but potential evaporation is high (3000 mm). Thus, the major source of water discharge comes from snowmelt and glacier-melt in the mountains. Though the water discharge into the Tarim River has experienced an increase over the past ten years, global climate change forecasts predict this water supply to decline within the century. The Tarim River is the major source of water in Northwestern China, and has become the hub of many economic activities related to agriculture and urban life. Over the past 50 years increased activity in the area has led to a severe decline in river flow. Both human and natural ecosystems have been impacted by water diversions. Since rainfall is rare, the majority of vegetation in this area depends solely on groundwater for survival, and plants are experiencing stress caused by decreasing groundwater levels. Recently nearby cities have experienced severe dust storms caused by the shrinking of the vegetative region along the river. SuMaRiO (Sustainable Management of River Oases) is a bundle project between Germany and China working to contribute to a sustainable land management which explicitly takes into account ecosystem functions (ESF) and ecosystem services (ESS). In a transdisciplinary research process, SuMaRiO will identify realizable management strategies, considering social, economic and ecological criteria. SuMaRiO is developing tools to work with Chinese decision makers to implement sustainable land management strategies. In addition, research is being conducted to estimate climate change impacts, floodplain biodiversity, and water runoff characteristics. The overarching goal of SuMaRiO is to support oasis management along

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

    Directory of Open Access Journals (Sweden)

    Qingke Nie

    2014-05-01

    Full Text Available 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.

  6. Mechanisms of low-flux intraplate volcanic fields - Basin and Range and Northwest Pacific Ocean

    Science.gov (United States)

    Valentine, G.; Hirano, N.

    2009-05-01

    Many fields of small-volume, scattered volcanoes that typically have alkaline affinities occur in intraplate settings. The underlying mechanisms of these intraplate volcanoes are enigmatic; they often do not correlate with anomalous heat sources or upwelling mantle (as in hot spots, mid-ocean ridges, and active continental rifts), or with fluids introduced by actively-subducting lithosphere. We compare the characteristics of two low volume-flux intraplate volcanic fields, one in a continental setting that is characterized by slow extension (western U.S.A.), and the other on the floor of the northwest Pacific Ocean in a region of plate flexure. The comparison supports an interpretation that the fundamental driving mechanism for low magma-flux volcanic fields, which episodically erupt scattered, small-volume volcanoes over millions of years, is regional-scale deformation of compositionally-heterogeneous upper mantle. Deformation serves to mechanically focus partial melts that might be present due to locally-depressed solidus temperatures caused by slightly higher volatile contents, creating sufficient melt buoyancy to trigger magma ascent via magma-driven fractures (dikes). The key role of deformation in collecting magmas and triggering dike ascent and eruption, without influx of new material or heat into the source region, supports the definition of such systems as tectonically-controlled, and is likely applicable at other low-flux, diffuse volcanic fields. Differences in the degree of fractionation and wall-rock contamination in the two fields is related to vertical variations in principal-stress orientation that may cause stalling of ascending dikes.

  7. 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 in the Xiangjiang River Basin (XJRB in China were analyzed. during the period from 1961 to 2010 was calculated with historical meteorological data using the FAO Penman-Monteith (FAO P-M method, while 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 were interpreted with the inverse distance weighted (IDW method and Mann-Kendall test method, respectively. Results show that: (1 the mean annual 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 and can be used to predict the future in the XJRB; and (3 CMIP5 predicts upward trends in annual under the RCP45 and RCP85 scenarios during the period from 2011 to 2100. Compared with the reference period (1961 to 1990, 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 under the RCP85 scenario is greater than that under the RCP45 scenario during the period from 2011 to 2100.

  8. Provenance and sediment dispersal of the Triassic Yanchang Formation, southwest Ordos Basin, China, and its implications

    Science.gov (United States)

    Xie, Xiangyang

    2016-04-01

    The Ordos Basin in north central China records a transition from marine to non-marine deposition during the late Paleozoic to early Mesozoic. As a result, the northern and southern regions of the Ordos Basin show different tectonic histories and very distinctive sedimentation styles. Two deformation belts, the Qinling orogenic belt to the south and the Liupanshan thrust and fold belt to the west, controlled the structural evolution of the southern Ordos Basin during the early Mesozoic. Paleocurrent analysis, net-sand ratio maps, sandstone modal analysis, and U-Pb detrital zircon geochronology were used to document sediment sources and dispersal patterns of the Triassic Yanchang Formation in the southwest Ordos Basin. Paleocurrent measurements suggest that the sediments were mainly derived from the Liupanshan and the Qinling orogenic belts. Net-sand ratio maps show that several fan delta systems controlled sediment delivery in the south Ordos Basin. Both sandstone modal analysis and U-Pb detrital zircon geochronology suggest that the Yanchang Formation is locally sourced from both of the basin marginal deformation belts; the lower and middle sections are recycled Paleozoic sedimentary rocks mainly derived from the north Qinling orogenic belt, whereas for the upper section, the Qilian-Qaidam terranes and possibly the west Qinling orogenic belt began to shed sediments into the southwest Ordos Basin. Results have important implications for basin marginal tectonics and its controls on sedimentation of intracratonic basins in China and similar settings.

  9. Discussion on marine source rocks thermal evolvement patterns in the Tarim Basin and Sichuan Basin, west China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Taking marine source rocks of lower Paleozoic in the Tarim Basin and Paleozoic ones in the Sichuan Basin as examples, their sedimentation process could be classified into four styles: continuous subsldence with deep sedimentation in early stage, continuous subsidence with deep sedimentation in later stage, that deeply buried-uplift-shallowly buried, and that shallowly buried-uplift-deeply buried.Unlike that in East China, the marine source rocks evolvement patterns did not accord with sedimentation styles one by one in superimposed basins in west China. Taking local geothermal field into account, four types of source rock evolvement patterns were built: that evolved fast in early stage,evolved fast in middle stage, evolved continuously and evolved in multistage. Among them, the 1st pattern contributed little to the present industrial oil pools directly, but paleo-oil reservoirs and gases cracked from crude oils were main exploration targets. Although some gases were found in the 2nd pattern, the scale was not big enough. For the 3rd and 4th patterns, the hydrocarbon potential depended on organic matters maturity in early stage. For relatively low mature rocks, it was possible to generate some oils in later stage; otherwise the main products were gases. Paleo-oil reservoirs remained fairly well in the Sichuan Basin, and most source rocks underwent kerogen-oil-gas processes,which was useful reference to gas exploration in the Tarim Basin.

  10. How to help woody plants to overcome drought stress?-a control study of four tree species in Northwest China.

    Science.gov (United States)

    Liu, Xiaozhen; Zhang, Shuoxin

    2010-05-01

    Water is essential for plants and involves most physical and chemical processes within their lifecycles. Drought stress is a crucial limiting factor for plant growth and production. 48% of the land in China is arid and semi-arid, and non-irrigated land occupies approximately 51.9% of the total cultivated areas. Therefore, studies on plant drought resistant mechanisms have great significance for improving water use efficiency and thus increasing productivity of economical plants. Prior research has shown that the application of nitrogenous fertilizer affects the drought-resistant characteristics of plants. This study aimed to reveal the effect of nitrogenous fertilizer on physiological aspects and its impact on the drought resistance of four tree species (Robinia pseudoacacia L., Ligustrum lucidum Ait., Acer truncatum Bge. and Ulmus pumila L. ) in northwest China. Three levels of nitrogen fertilization (46% N based of urea adjusted to: 5g/15g soil, 15g/15g soil and 25g/15g soil) and an additional control study were applied to 2-year-old well-grown seedlings under drought conditions (30% field moisture capacity). Stomatal conductance, transpiration rate and net photosynthetic rate were measured by a LI-6400 photosynthesis system, while water use efficiency was calculated from net photosynthesis rate and transpiration rate. The results revealed that as the amount of urea applied was raised, stomatal conductance, transpiration rate and net photosynthetic rate decreased significantly, and thus water use efficiency significantly increased. It is therefore concluded that the application of nitrogenous fertilizer regulated physiological parameters by reducing stomata conductance to improve water use efficiency. In addition, among the four tree species, U. pumila had the maximum value of water use efficiency under the same drought condition. The outcome of this study provides a guided option for forest management in arid and semi-arid areas of northwest China.

  11. Application of Mulching Materials of Rainfall Harvesting System for Improving Soil Water and Corn Growth in Northwest of China

    Institute of Scientific and Technical Information of China (English)

    HAN Juan; JIA Zhi-kuan; HAN Qing-fang; ZHANG Jie

    2013-01-01

    The ridge and furrow rainfall harvesting (RFRH) system is used for dryland crop production in northwest of China. To determine the effects of RFRH using different mulching materials on corn growth and water use efifciency (WUE), a ifeld experiment was conducted during 2008-2010 at the Heyang Dryland Experimental Station, China. Four treatments were used in the study. Furrows received uncovered mulching in all RFRH treatments whereas ridges were mulched with plastic iflm (PF), biodegradable iflm (BF) or liquid iflm (LF). A conventional lfat ifeld without mulching was used as the control (CK). The results indicated that the average soil water storage at depths of 0-200 cm were 8.2 and 7.3%, respectively higher with PF and BF than with CK. However, LF improved soil water storage during the early growth stage of the crop. Compared with CK, the corn yields with PF and BF were increased by 20.4 and 19.4%, respectively, and WUE with each treatment increased by 23.3 and 21.7%, respectively. There were no signiifcant differences in corn yield or WUE with the PF and BF treatments. The net income was the highest with PF, followed by BF, and the 3-yr average net incomes with these treatments were increased by 2 559 and 2 430 CNY ha-1, respectively, compared with CK. BF and PF had similar effects in enhancing the soil water content, crop yield and net income. Therefore, it can be concluded that biodegradable iflm may be a sustainable ecological alternative to plastic iflm for use in the RFRH system in northwest of China.

  12. Geothermal Regime, Thermal History and Hydrocarbon Generation Types of Sedimentary Basins in the Continental Area of China

    Institute of Scientific and Technical Information of China (English)

    QiuNansheng; JamesPuckette; JinZhijun; WangJiyang

    2005-01-01

    The thermal regimes in sedimentary basins in the continental area of China are varied and reflect differences in geological settings. As a result of these variable thermal regimes, the history of hydrocarbon generation in each basin is also different. An east-west profile of the thermal threshold across the continental basins of China, like the Liaohe Basin, the North China Basin, the Ordos Basin, the Qaidam Basin and the Tarim Basin, was constructed using large numbers of heat flow measurements, temperature data and rock thermophysical parameters. Isotherms, surface heat flow, mantle heat flow and Moho temperature beneath the basins are shown in the profile, which illustrates changes in some thermal characteristics between basins in east China and those in west China. Thermal evolution histories in basins were reconstructed using Easy%Ro method, apatite fission track annealing and other paleothermometers. Typical hydrocarbon generation histories of the primary source rocks were modeled by referring to the thermal evolution data. Thermal stages controlled source rocks maturation and oil and gas generation, and influenced the type of hydrocarbon (oil and gas) production in the basins.

  13. Neogene coupling between Kuqa Basin and Southern Tien Shan Orogen, Northwestern China.

    Science.gov (United States)

    He, Guang-Yu; Chen, Han-Lin

    2004-08-01

    Based on the sedimentary and subsiding features of Kuqa foreland basin, this paper presents the following characteristics of Neogene coupling relationship between Kuqa Basin and Southern Tien Shan Orogen, Northwestern China: (1) The Southern Tien Shan Orogen underwent Neogene uplifting of 4 km in height and the Kuqa Basin underwent Neogene subsidence of 4-6 km in depth accordingly beginning in 25 Ma; (2) The Southern Tien Shan Orogen moved continuously toward the Kuqa Basin, with largest structural shortening rate of greater than 53.7%, and the north boundary of the Kuqa Basin retreated continuously southward accordingly since the Miocene; (3) There are two subsidence centers with high subsiding rates and large subsiding extent, located in the eastern and western Kuqa Basin respectively, with the subsiding maximizing in the deposition period of Kuqa Formation. PMID:15236483

  14. Neogene coupling between Kuqa Basin and Southern Tien Shan Orogen, Northwestern China

    Institute of Scientific and Technical Information of China (English)

    何光玉; 陈汉林

    2004-01-01

    Based on the sedimentary and subsiding features of Kuqa foreland basin, this paper presents the following characteristics of Neogene coupling relationship between Kuqa Basin and Southern Tien Shan Orogen, Northwestern China:(l) The Southern Tien Shan Orogen underwent Neogene uplifting of 4 km in height and the Kuqa Basin underwent Neogene subsidence of 4-6 km in depth accordingly beginning in 25 Ma; (2) The Southern Tien Shan Orogen moved continuously toward the Kuqa Basin, with largest structural shortening rate of greater than 53.7%, and the north boundary of the Kuqa Basin retreated continuously southward accordingly since the Miocene; (3) There are two subsidence centers with high subsiding rates and large subsiding extent, located in the eastern and western Kuqa Basin respectively, with the subsiding maximizing in the deposition period of Kuqa Formation.

  15. Mechanisms of Cenozoic deformation in the Bohai Basin, Northeast China: Physical modelling and discussions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The Bohai Basin is a Cenozoic petroliferous extensional basin in China and has apparent geometrical and kinematic similarities with the other Meso-Cenozoic extensional basins located along the eastern margin of Eurasian Plate. However, the deformation mechanisms of the basin are still in dispute. Physcial modelling referring to the Huanghua Depression, located in the central part of the Bohai Basin was conducted employing four sets of planar sandbox experimental models with different extension directions. Only experimental results of the model with N-S extension show good structural similarity with the depression. The results also indicate that complex variations of fault strike in a rift basin are not necessarily the results of complex kinematic mechanisms or polyphase deformation. Based on comparison of experimental results with the actual structures and the good structural similarity between Huanghua Depression and the whole Bohai Basin, it is concluded that the Bohai Basin was formed by the N-S extension. The strike slip deformation along the NNE-trending border faults of the basin resulted from the N-S extension and played the role of lateral transformation for the N-S extension. In addition, according to the apparent geometrical and kinematic similarities among the Bohai Basin and other Meso-Cenozoic extensional basins located along the eastern margin of the Eurasian Plate, it is proposed that: (1) this "N-S extension" model provides a better kinematic interpretation for the formation of Bohai Basin and the other adjacent basins located along the eastern margin of the Eurasian Plate; and (2) the N-S extension was probably the effect of the "slab window" formed by the subduction of the nearly E-W trending oceanic ridge between the Kula and Pacific Plates. The "slab window" effect can also provide reasonable explanations for the phenomena that initial rifting ages of basins become progressively younger westwards along the eastern margin of the Eurasian Plate

  16. Efects of Crop Growth on Hydrological Processes in River Basins and on Regional Climate in China

    Institute of Scientific and Technical Information of China (English)

    QIN; Pei-Hua; CHEN; Feng; XIE; Zheng-Hui

    2013-01-01

    The regional climate model RegCM3 incorporating the crop model CERES,called the RegCM3CERES model,was used to study the efects of crop growth and development on regional climate and hydrological processes over seven river basins in China.A 20-year numerical simulation showed that incorporating the crop growth and development processes improved the simulation of precipitation over the Haihe River Basin,Songhuajiang River Basin and Pearl River Basin.When compared with the RegCM3 control run,RegCM3CERES reduced the negative biases of monthly mean temperature over most of the seven basins in summer,especially the Haihe River Basin and Huaihe River Basin.The simulated maximum monthly evapotranspiration for summer(JJA)was around 100 mm in the basins of the Yangtze,Haihe,Huaihe and Pearl Rivers.The seasonal and annual variations of water balance components(runof,evapotranspiration and total precipitation)over all seven basins indicate that changes of evapotranspiration agree well with total precipitation.Compared to the RegCM3,RegCM3CERES simulations indicate reduced local water recycling rate over most of the seven basins due to lower evapotranspiration and greater water flux into these basins and an increased precipitation in the Heihe River Basin and Yellow River Basin,but reduced precipitation in the other five basins.Furthermore,a lower summer leaf area index(1.20 m2m 2),greater root soil moisture(0.01 m3m 3),lower latent heat flux(1.34 W m 2),and greater sensible heat flux(2.04 W m 2)are simulated for the Yangtze River Basin.

  17. Water resources utilization and eco-environmental responses in arid areas in Northwest China:A case study in Baiyang River Basin in Xinjiang%西北干旱区水资源利用与生态环境响应研究--以新疆白杨河流域为例

    Institute of Scientific and Technical Information of China (English)

    孟江丽

    2013-01-01

      为了白杨河流域内莫合台洼地、白杨河洼地、艾里克湖3大区域的生态不被破坏,确保白杨河水库可以给下游艾里克湖输水,在研究白杨河流域水资源开发利用现状的基础上,设定白杨河拟建引水枢纽至白杨河水库之间的河段进行全防渗和部分防渗两套输水工程方案,并通过遥感技术、蒸散模型和水量平衡模型,统筹考虑上、中、下游的用水情况,建立水资源开发利用方案与3大生态保护目标之间的响应关系,对河段全防渗和部分防渗两个输水工程方案对3大生态保护目标所产生的影响进行对比分析。结果表明,部分防渗方案对生态的影响较小,部分防渗方案是合理的输水工程方案。%In order to protect the eco-environment of the Mohetai Billabong , the Baiyang River Billabong, and Ailike Lake, and to transfer water from the Baiyang River Reservoir to Ailike Lake , two projects were carried out to transfer water through a pipeline all along the river channel and part of the channel between the Baiyang River Sluice and the Baiyang River Reservoir , based on study of the actual status of water resources utilization in the Baiyang River Basin.The remote sensing technology , the evaporation-transpiration model, and the water balance model were used to analyze the response relation between the water resources utilization scheme and the eco -environment, with consideration of water utilization in the upper , middle, and lower reaches.The effects of the two projects on the eco-environment of the Mohetai Billabong , the Baiyang River Billabong, and Ailike Lake were compared.The results show that to transfer water through the pipeline along part of the river channel was reasonable.

  18. Impact of land-use change on hydrological processes in the Maying River basin, China

    Institute of Scientific and Technical Information of China (English)

    WANG; Genxu; ZHANG; YU; LIU; Guimin

    2006-01-01

    Since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of China. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest China, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors,i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large areas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 28.12%, a base flow decline of 35.32%, a drop in the maximum peak discharge of 35.77%, and mean discharge decreases in spring and autumn of 36.05% and 24.87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73%-81%,and that to the influence of base flow reaching 62%-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.

  19. Status of cardiovascular health among adults in a rural area of Northwest China: Results from a cross-sectional study.

    Science.gov (United States)

    Zhao, Yaling; Yan, Hong; Yang, Ruihai; Li, Qiang; Dang, Shaonong; Liu, Ruru; Pei, Leilei; Cao, Lei; Marshall, Roger J; Wang, Duolao

    2016-07-01

    The aim of this study was to assess the status of cardiovascular health among a rural population in Northwest China and to determine the associated factors for cardiovascular health.A population-based cross-sectional study was conducted in the rural areas of Hanzhong in Northwest China. Interview, physical examination, and fasting blood glucose and lipid measurements were completed for 2693 adults. The construct of cardiovascular health and the definitions of cardiovascular health metrics proposed by the American Heart Association were used to assess cardiovascular health. The proportions of subjects with cardiovascular health metrics were calculated, adjusting for age and sex. The multiple logistic regression model was used to evaluate the association between ideal cardiovascular health and its associated factors.Only 0.5% (0.0% in men vs 0.9% in women, P = 0.002) of the participants had ideal cardiovascular health, whereas 33.8% (18.0% in men vs 50.0% in women, P health, respectively. The prevalence of poor cardiovascular health increased with increasing age (P health metrics. Also, 22.2% of the participants presented with 3 or fewer ideal metrics. Only 19.4% of the participants presented with 6 or more ideal metrics. 24.1% of the participants had all 4 ideal health factors, but only 1.1% of the participants had all 4 ideal health behaviors. Women were more likely to have ideal cardiovascular health, whereas adults aged 35 years or over and those who had a family history of hypertension were less likely to have ideal cardiovascular health.The prevalence of ideal cardiovascular health was extremely low among the rural population in Northwest China. Most adults, especially men and the elderly, had a poor cardiovascular health status. To improve cardiovascular health among the rural population, efforts, especially lifestyle improvements, education and interventions to make healthier food choices, reduce salt intake, increase physical activities, and cease

  20. Stratigraphy and Geochemistry of the Lower Permian Esayoo Volcanics, Northwest Ellesmere Island: Insights into Sverdrup Basin Paleogeography

    Science.gov (United States)

    Morris, N. J.; Beauchamp, B.; Cuthbertson, J. P.; Chau, Y.

    2012-12-01

    The Esayoo Volcanics consist of altered Lower Permian basalts that outcrop on northwest Ellesmere Island and northeast Axel Heiberg, within the Sverdrup Basin, Arctic Canada. Rifting in the Sverdrup Basin initiated in the Early Carboniferous and ceased during the Early Permian. The Esayoo volcanics geochemically classify as alkaline to transitional within-plate-basalts, with high Ti/Y and Zr/Y ratios. Eruptions are coincident with two rifting pulses of Sakmarian and Kungurian age. During the 2011 July field season, ten stratigraphic sections of the Esayoo Volcanics were measured at four locations on northwest Ellesmere Island: Borup Fiord Pass, Oobloyah Bay, Ricker Glacier and Mount Leith. The Esayoo Volcanics reach a maximum thickness of 450 m near Oobloyah Bay, and thin west, east and north of Oobloyah Bay with respective thicknesses of 140 m, 69 m and 75 m. At Oobloyah Bay, volcanic rocks occur at two stratigraphic levels. The lower Esayoo unit lies within the Raanes Formation, a mixed clastic-carbonate, and further west at Ricker Glacier within the upper Hare Fiord Formation, a black siliceous shale-siltstone. The upper Esayoo unit is below the Assistance Formation, carbonate-rich to clean quartz sandstone, and below the Sabine Bay Formation, a clean quartz sandstone with abundant cross-beds. Thin 1 to 2 m shales that indicate maximum flooding surfaces overlie both the upper and lower Esayoo units. Each measured section was divided into individual flow units that averaged 7 m thick. Dominant textures observed within individual flow units include: thin 2-3 cm thick amygdule-rich bases transitioning into thick 2-10 m thick massive flow interiors; frothy, amygdule-rich flow tops 1-3 m thick; and chaotic vesicular units with amygdules ranging from 0.5-3 cm in width and pervasive cross-cutting calcite veins and stringers. The lower level at Oobloyah Bay is composed of a laminated volcaniclastic rock that is rich in heterozoan marine bioclasts, with associated pillow

  1. Land Use Changes of an Aeolian-Loessial Soil Area in Northwest China: Implications for Ecological Restoration

    Institute of Scientific and Technical Information of China (English)

    CHEN Yu-Fu; LIU Yan-Sui; WANG Jing; YAN Jian-Ping; GUO Xu-Dong

    2009-01-01

    China has experienced dramatic land use changes over recent decades,with marked environmental and socio-economic consequences.Hcngshan County,located in the aeolian-loessial area of Northwest China,was investigated to illustrate land use changes and their implications for environmental and long-term rural economic development.The farmland in Hengshan County significantly decreased during 1990-2003,whereas forest land and grassland increased.The conversion rates of farmland,orchard land,forest land and construction land varied markedly among different periods:1990-1995,1995-2000 and 2000-2003.Conversion of orchard land,grassland and construction land was dominant in 1990-1995,whereas the conversion of farmland to forest land mainly occurred in 2000-2003.The results suggested a profound transition in institutional policy and political economy of land management,including implementation of integrated soil erosion control projects,adoption of a market-oriented economy and the 'Grain-for-Green' policy,during this period in China.To achieve long-term sustainable land use in Hengshan County,efforts should aim at increasing off-farm income of rural families as well as establishing land-economizing mechanisms to promote land productivity,in addition to conservation measures.

  2. Multifractal analyses of daily rainfall time series in Pearl River basin of China

    OpenAIRE

    Yu, Zu-Guo; Leung, Yee; Chen, Yongqin David; Qiang ZHANG; Van Anh, Vo; Zhou, Yu

    2014-01-01

    The multifractal properties of daily rainfall time series at the stations in Pearl River basin of China over periods of up to 45 years are examined using the universal multifractal approach based on the multiplicative cascade model and the multifractal detrended fluctuation analysis (MF-DFA). The results from these two kinds of multifractal analyses show that the daily rainfall time series in this basin have multifractal behavior in two different time scale ranges. It is found that the empiri...

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

    OpenAIRE

    Bei, Naifang; Li, Guohui; Huang, Ru-Jin; Cao, Junji; Meng, Ning; Feng, Tian; Liu, Suixin; Zhang, Ting; Zhang, Qiang; Molina, Luisa T.

    2016-01-01

    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”, “trans...

  4. Testing new methodologies and assessing their potential for reservoir characterisation: Geoelectrical studies in the Northwest Carboniferous Basin (Ireland).

    Science.gov (United States)

    Ogaya, Xènia; Campanyà, Joan; Rath, Volker; Jones, Alan G.; Reay, Derek; Raine, Rob; McConnell, Brian; Ledo, Juanjo

    2016-04-01

    The overarching objective of this study is to improve our methods of characterising saline aquifers by integrating newly acquired electromagnetic data with existing geophysical and geological data. The work presented here is part of an ongoing project to evaluate Ireland's potential for onshore carbon sequestration (IRECCSEM; funded by Science Foundation Ireland). The methodology presented in this characterisation work is not only relevant for studying the potential for onshore carbon sequestration, but is generally applicable for aquifer characterisation, particularly for the evaluation of geothermal resources in appropriate geological settings. We present first results of the three-dimensional (3D) modelling and inversion of the magnetotelluric (MT) data acquired in the Northwest Carboniferous Basin (Ireland) in summer 2015. The electrical resistivity distribution beneath the survey area is constrained using a joint inversion of three different types of electromagnetic data: MT impedance tensor responses (Z), geomagnetic transfer functions (GTF) and inter-station horizontal magnetic transfer-functions (HMT). The preliminary 3D resistivity model obtained reveals the geoelectrical structure of the subsurface, which is translated into parameters relevant to fluid flow. The electromagnetic data were acquired along profiles linking four wells drilled in the area and the available well log data from those wells are used to evaluate some of the existing petrophysical relationships and calibrate them for the study area. This allows us to interpolate the rock physical properties from one well to another well, using the computed geoelectrical model as a reference. The obtained results are compared to available independent geological and geophysical data in order to analyse the validity of this technique, to characterise the uncertainties inherent to our approach, and to assess the potential of this methodology for reservoir characterisation.

  5. Basin Fluid Mineralization during Multistage Evolution of the Lanping Sedimentary Basin, Southwestern China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Lanping sedimentary basin has experienced a five-stage evolution since the late Paleozoic: ocean-continent transformation (late Paleozoic to early mid-Triassic); intracontinental rift basin (late mid-Triassic to early Jurassic); down-warped basin (middle to late Jurassic); foreland basin (Cretaceous); and strike-slip basin (Cenozoic). Three major genetic types of Ag-Cu polymetailic ore deposits, including the reworked hydrothermal sedimentary, sedimentary-hydrothermally reworked and hydrothermal vein types, are considered to be the products of basin fluid activity at specific sedimentary-tectonic evolutionary stages. Tectonic differences of the different evolutionary stages resulted in considerable discrepancy in the mechanisms of formation-transportation, migration direction and emplacement processes of the basin fluids, thus causing differences in mineralization styles as well as in genetic types of ore deposit.

  6. Accumulation and source of heavy metals in sediment of a reservoir near an industrial park of northwest China

    Science.gov (United States)

    Zhu, Yuanjie; Lu, Xinwei; Yang, Linna; Wang, Lijun

    2016-02-01

    The accumulation and source of heavy metals As, Ba, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn in the surface sediment of a reservoir near an industrial park of northwest China were determined by enrichment factor and multi-variate statistical analysis. Multivariate statistical analyses, i.e., factor analysis, cluster analysis, and correlation coefficient analysis, were used to identify the possible sources of the heavy metals. The results show that the mean concentrations of As, Ba, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn in the reservoir sediment are higher than their corresponding concentrations in the control sample, indicating all analyzed heavy metals accumulated in the surface sediments. The values of the mean concentrations of heavy metals in the surface sediment divided by their corresponding concentrations in the control sample increase in the order of Ba = Crindustrial sources and local consumption residues; Pb and Zn mainly originate from industrial activities, while Ba and Cr primarily originate from natural sources.

  7. 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

    2016-05-01

    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.

  8. Discussion on the characteristics of Meso-Cenozoic U-productive basins in northern China and their prospecting direction

    International Nuclear Information System (INIS)

    Based on the study of sedimentary evolution characteristics of main sedimentary basins and combined with characteristics of known uranium-productive basins in northern China, and the analysis on airborne geophysical survey data, the principles for selecting prospecting and target area have been set up. And the prospecting direction for uranium in Meso-Cenozoic basins of northern China has been proposed through a preliminary analysis. (authors)

  9. 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.

  10. Failure patterns and survival in patients with nasopharyngeal carcinoma treated with intensity modulated radiation in Northwest China: A pilot study

    International Nuclear Information System (INIS)

    To evaluate the clinical outcomes and patterns of failure in patients with nasopharyngeal carcinoma (NPC) treated with intensity modulated radiotherapy (IMRT) in Northwest China. From January 2006 to December 2009, 138 NPC patients were treated at Xijing Hospital. Of them, 25 cases with stage I-II received IMRT only, 113 cases with stage III-IVb received IMRT plus accomplished platinum-based chemotherapy. The IMRT prescribed dose was PTV 68-74 Gy to gross disease in nasopharynx and 66-72 Gy to positive lymph nodes in 30-33 fractions, and high risk and low risk region PTV was 60-63 Gy and 50.4~56 Gy in 30~33 and 28 fractions respectively. Plasma Epstein Barr virus (EBV) DNA load was measured before treatment. The clinical toxicities, outcomes and patterns of failure were observed. The median follow up time was 23 months (range 2 to 53 months). EBV infection positive was only 15.9%. Overall disease failure developed in 36 patients, 99% belonged to stage III/IV disease. Among these, there were 26 distant metastases, 6 local recurrence, and 4 regional recurrence. The 3-year local control rate(LCR), distant metastasis-free survival (MFS), disease-free survival (DFS) and the overall survival (OS) was 93.9%, 79.5%, 70% and 83.1% respectively. Multivariate analyses revealed that age and anemia pre-radiotherapy were independent predictors for OS. IMRT with or without chemotherapy can improve the long term survival of NPC patients in Northwest China. Distant metastasis becomes the main cause of treatment failure. Age and anemia before radiotherapy were the main prognosis factors of NPC patients

  11. 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. PMID:26439928

  12. Recent developments in study of the typical superimposed basins and petroleum accumulation in China: Exemplified by the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    JIN; Zhijun; WANG; Qingchen

    2004-01-01

    Most of petroliferous sedimentary basins in China have experienced multiple phases of tectonic evolution and deposition, and are characterized by tectonic and depositional superimposition. The term "superimposed basin" is suggested to describe those basins which consist of two or more simple prototype basins superimposing vertically and/or coalescing laterally. The characteristics of petroliferous superimposed basins are "multiple stages of basin forming and reworking, multiple layers of source rocks, multiple periods of hydrocarbon generation and expulsion, multiple periods of petroleum migration-accumulation-escape". Therefore,applying the wave process analysis method to studying the process of basin formation, hydrocarbon generation, and reservoir formation, and then establishing theory of "petroleum accumulation system" is helpful to enhancing petroleum exploration efficiency in superimposed basins.This paper will, based on case study in the Tarim basin, report the major developments in studying basin formation, hydrocarbon generation and petroleum accumulation. In study of basin formation, (1) geophysical comprehensive profiles reveal that the Tarim plate has been subducted beneath the Tianshan orogenic belt with an interfinger structure and that the deep structure in the eastern section of the Tianshan orogenic belt is different from that in the western section. (2) The vertical variation in debris and geochemical composition reveals the nature and Mesozoic-Cenozoic evolution history of the Kuqa Depression. (3) Field investigation and paleostress reconstruction show that the Kuqa Depression has undergone gravity-driven extension in sedimentary cover when the Tianshan uplifted vertically. In hydrocarbon generation study, new developments include (1) setting environmental index to judge high grade source rocks in marine carbonates, and (2) establishing the lower limit of the organic carbon content for effective carbonate source rocks. In petroleum accumulation

  13. Recent developments in study of the typical superimposed basins and petroleum accumulation in China:Exemplified by the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    JIN Zhijun; WANG Qingchen

    2004-01-01

    Most of petroliferous sedimentary basins in China have experienced multiple phases of tectonic evolution and deposition, and are characterized by tectonic and depositional superimposition. The term "superimposed basin" is suggested to describe those basins which consist of two or more simple prototype basins superimposing vertically and/or coalescing laterally. The characteristics of petroliferous superimposed basins are "multiple stages of basin forming and reworking, multiple layers of source rocks, multiple periods of hydrocarbon generation and expulsion, multiple periods of petroleum migration-accumulation-escape". Therefore,applying the wave process analysis method to studying the process of basin formation, hydrocarbon generation, and reservoir formation, and then establishing theory of "petroleum accumulation system" is helpful to enhancing petroleum exploration efficiency in superimposed basins.This paper will, based on case study in the Tarim basin, report the major developments in studying basin formation, hydrocarbon generation and petroleum accumulation. In study of basin formation, (1) geophysical comprehensive profiles reveal that the Tarim plate has been subducted beneath the Tianshan orogenic belt with an interfinger structure and that the deep structure in the eastern section of the Tianshan orogenic belt is different from that in the western section. (2) The vertical variation in debris and geochemical composition reveals the nature and Mesozoic-Cenozoic evolution history of the Kuqa Depression. (3) Field investigation and paleostress reconstruction show that the Kuqa Depression has undergone gravity-driven extension in sedimentary cover when the Tianshan uplifted vertically. In hydrocarbon generation study, new developments include (1) setting environmental index to judge high grade source rocks in marine carbonates, and (2) establishing the lower limit of the organic carbon content for effective carbonate source rocks. In petroleum accumulation

  14. On the Origin of One Basin-Multiple Mountain Couplings in the Mesozoic-Cenozoic Basin-Range Area in Eastern North China

    Institute of Scientific and Technical Information of China (English)

    NIU Shuyin; SHAO Ji'an; HOU Quanlin; WANG Baode; XU Chuanshi

    2004-01-01

    The basin-range coupling relation is a leading subject of the modern geology. In geometry, relations of this type include couplings between stretched orogenic belt and down-faulted basin, compressional orogenic belt and foreland basin, strike-slip orogenic belt and strike-slip basin and so on. Fault chains are the key for these couplings and there are typical examples for all these cases. The North China down-faulted basin is coupled west with the Tathang uplift, east with the Jiao-Liao Mountains, north with the Yanshan orogenic belt and south with the Dabie orogenic belt,that is to say, the central down-faulted basin and the surrounding orogenic belts bear a coupling relation within a uniform dynamistic system. Study shows that the central down-faulted basin and the North China mantle sub-plume structure have a close relation during their formation. Owing to intensive mantle sub-plume uplifting, the bottom of the lithosphere suffered from resistance, which caused the lithosphere of the eastern North China to be heated, thinned and fault-depressed. Meanwhile, mantle rocks that were detached outwards in the shape of mushroom was dissected by surrounding ductile shearing zones, which lead to decompression and unloading to generate hypomagmas, and a series of mantle-branch structures were formed around the down-faulted basin. There is an obvious comparability among these mantle branch structures (orogenic belts), and they have basin-range coupling relations with the central down-faulted basins.

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

    Institute of Scientific and Technical Information of China (English)

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

    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 ~nsporters 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.

  16. Multi-proxy evidence for Late Pleistocene Holocene climatic and environmental changes in Lop-Nur, Xinjiang, Northwest China

    Institute of Scientific and Technical Information of China (English)

    LUO Chao; YANG Dong; PENG Zicheng; ZHANG Zhaofeng; LIU Weiguo; HE Jianfeng; ZHOU Chenlin

    2008-01-01

    A 10.35-m-long sediment core from the Luobei depression in Lop-Nur, Xinjiang, Northwest China, provides detailed information about environmental changes during the Late Pleistocene. The samples taken every 5 cm of the core were unalyzed for 10 environmental proxies, including magnetic susceptibility, granularity, chroma, carbonate and loss on ignition (LOI), and pH value. The chronology data are provided by the uranium/thorium disequilibrium dates. The sediments of the section were deposited during the last 32000 years. The results of analysis of 10 proxies were examined using multivariate statistical analysis, and the principal components were calculated. According to the results, the Late Pleistocene sequence contains four climatic and environmental stages appearing in the cycles of cold-wet and warm-dry changes. During 10-9 ka BP, it was the earliest warm episode in the Holocene.Environmental changes in this district were restricted by global change, as suggested by the analysis of glacial-interglacial cycles. But it was different from the mutative trend of a monsoon region in East China because of its own characteristics, which was the situation of cold-wet and warm-dry climate-environment change. The candidate reason may be the uplift of the Tibet Plateau and the westerly wind circulation.

  17. Thermal-rheological structure of the lithosphere beneath two types of basins in eastern and western China

    Institute of Scientific and Technical Information of China (English)

    王良书; 李成; 刘福田; 李华; 卢华复; 刘绍文

    2000-01-01

    After calculating thermal-rheological properties of the lithosphere in the Northern Jiangsu basin, the Bohaiwan basin as well as the Jiyang depression in the east and Tarim basin in the west of China, this paper analyzes the relationship between thermal-rheological structures and tectonic evolution of the two types of basins. The results show that the thermal-rheoiogical structures of the lithosphere directly reflect the dynamic processes. Under different dynamic environments, the style of basin formation and the differences in basin evolution are closely related to the dynamic properties of the lithosphere indicated by thermal-rheological structures.

  18. Magnitude, frequency and timing of floods in the Tarim River basin, China: Changes, causes and implications

    Science.gov (United States)

    Zhang, Qiang; Gu, Xihui; Singh, Vijay P.; Sun, Peng; Chen, Xiaohong; Kong, Dongdong

    2016-04-01

    The flood magnitude, frequency and timing were analyzed using daily flow data for a period of 1950-2007 from 8 stations in the Tarim River basin, a typical arid inland river basin in China. The causes for flood occurrences were investigated using daily meteorological data. Results indicated that precipitation and temperature were increasing persistently since the 1980s and significant increases in precipitation and temperature were observed after the 1990s. As a result, floods amplified at annual and seasonal time scales in most tributary basins after the 1980s. The floods in the basin are mainly attributed to rainstorms and melting of glaciers and snowpack, and rainstorm-induced floods and temperature-induced floods were dominant in the basin. Extreme floods, such as the three largest recorded floods and floods with return periods > 10 years occurred mainly after the 1990s, with significant increase in flood-induced crop and livestock losses. It was found that heavy floods in many tributary basins often occurred about the same time. The Tarim River basin is a typical arid inland river basin in a high altitude zone and amplifying floods in recent decades, particularly after 1990s, is arousing considerable concern for mitigation of flood hazards. Results of this study shed light on hydrological response of arid regions to warming climate at higher latitudes in the northern hemisphere.

  19. 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.

  20. 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

  1. 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.

  2. Afforestation for reduction of NOx concentration in Lanzhou China

    OpenAIRE

    Chu, P. C.; Chen, Y. C.; Lu, S. H.

    2008-01-01

    Lanzhou is one of the major industrial cities in northwest China, the capital of Gansu Province, and located at a northwest-to-southeast oriented valley basin with elevation about 1500–1600-m. Due to topographic and meteorological characteristics, Lanzhou is one of the most polluted cities in China. Meteorological conditions (low winds, stable stratification especially inversion), pollutant sources and sinks affect the air quality. Lanzhou government carried out afforestation and pol...

  3. Source, evolution and emplacement of Permian Tarim Basalts: Evidence from U-Pb dating, Sr-Nd-Pb-Hf isotope systematics and whole rock geochemistry of basalts from the Keping area, Xinjiang Uygur Autonomous region, northwest China

    Science.gov (United States)

    Zhang, Dayu; Zhou, Taofa; Yuan, Feng; Jowitt, Simon M.; Fan, Yu; Liu, Shuai

    2012-04-01

    Permian basalts distribute at least 250,000 km2, and underlie the southwest Tarim Basin in Xinjiang Uygur Autonomous region, northwest China. This vast accumulation of basalt is the main part of the Tarim Large Igneous Province (LIP). The basaltic units in the Lower Permian Kupukuziman and Kaipaizileike Formations in the Keping area, Tarim Basin; were the best exposure of the Permian basalt sequence in the basin. LA-ICP-MS U-Pb dating of zircon from the basal basaltic unit in the section gives an age of 291.9 ± 2.2 Ma (MSWD = 0.30, n = 17); this age, combined with previously published geochronological data, indicates that the basalts in the Tarim Basin were emplaced between 292 Ma and 272 Ma, with about 90% of the basalts being emplaced between 292 and 287 Ma. Basalts from the Keping area have high FeOT (10.8-18.6 wt.%), low Mg#s (0.26-0.60), and exhibit primitive mantle normalized patterns with positive Pb, P and Ti but negative Zr, Y and Ta anomalies. The basalts from both formations have similar 206Pb/204Pb (18.192-18.934), 207Pb/204Pb (15.555-15.598) and 208Pb/204Pb (38.643-38.793) ratios. The basalts also have high ɛSr(t) (45.7-62.1), low ɛNd(t) (-3.6 to -2.2) and low zircon ɛHf(t) (-4.84 to -0.65) values. These characteristics are typical of alkali basalts and suggest that the basalts within the Tarim Basin were derived from an OIB-type mantle source and interacted with enriched mantle (EMI-type) before emplacement. Rare earth element systematics indicate that the parental melts for the basalts were high-degree partial melts derived from garnet lherzolite mantle at the base of the lithosphere. Prior to emplacement, the Tarim Permian Basalts (TPB) underwent fractional crystallization and assimilated crustal material; the basalts were finally emplaced during crustal extension in an intra-plate setting. The wide distribution, deep source and high degree partial melting of the TPB was consistent with a mantle plume origin. The TPB and other coeval igneous

  4. On the Establishment of Green Fiscal Transfer Payment Mechanism in Northwest Ethnic Regions of China

    OpenAIRE

    Afan Sun

    2014-01-01

    The building of a resource-saving and environment-friendly society has become one of the important tasks in China, which makes for promoting economic, culture, social, and ecological civilization development in accordance with the overall arrangements for the cause of Socialism with Chinese characteristics. The layout of the strategy of development priority zones is conductive to realize the goal. According to the strategy of development priority zone¡¯s special ecological protection requirem...

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

    Science.gov (United States)

    Wei, N.; Qiu, Y.; Gan, H.; Niu, C.; Liu, J.; Gan, Y.; Zhou, N.

    2014-09-01

    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.

  6. Subsurface structure and stratigraphy of the northwest end of the Turkana Basin, Northern Kenya Rift, as revealed by magnetotellurics and gravity joint inversion

    Science.gov (United States)

    Abdelfettah, Yassine; Tiercelin, Jean-Jacques; Tarits, Pascal; Hautot, Sophie; Maia, Marcia; Thuo, Peter

    2016-07-01

    In order to understand the subsurface stratigraphy and structure of the northwest end of the Turkana Basin, Northern Kenya Rift, we used 2-D joint inversion of magnetotelluric (MT) and gravity data acquired along 3 profiles perpendicular to the main Murua Rith-Lapur Rift Border Fault. The regional geology is characterized by a basement of Precambrian age overlain by a ≤500-m thick sandstone formation named the Lapur Sandstone of upper Cretaceous-lower Eocene in age, covered by thick rhyolitic and basaltic lavas of late Eocene-middle Miocene age, known as the "Turkana Volcanics". Final interpretation of the resistivity and density models, until 5 km depth, obtained by the joint inversion approach confirms the previous general knowledge about the half-graben geometry of the northern part of the Turkana Basin. The main Murua Rith-Lapur Rift Border Fault is well identified by both gravity and MT. At least, two other important secondary faults without surface expression are also identified. A new small half-graben basin, named the Kachoda Basin, parallel to the main Turkana Basin and filled by 1.5 km of sediments, has been also characterized. This study also highlights strong thickness variations of the three main geological units that could be expected in the subsurface of the Turkana Basin. For example, the sedimentary Nachukui and Kibish Formations reach up to >3 km in thickness at the eastern end of the north and central profiles. Lateral variations of the topography of the Precambrian basement are also evidenced. Conceptual geological models, which result from the combination of the obtained density and resistivity models as well as from geological and reflection seismic data, are proposed. In such an area of intensive and promising oil exploration, these models are essential in terms of identification of reservoirs, source rocks and trapping mechanisms.

  7. Exploration of drought evolution using numerical simulations over the Xijiang (West River) basin in South China

    Science.gov (United States)

    Niu, Jun; Chen, Ji; Sun, Liqun

    2015-07-01

    The knowledge of drought evolution characteristics may aid the decision making process in mitigating drought impacts. This study uses a macro-scale hydrological model, Variable Infiltration Capacity (VIC) model, to simulate terrestrial hydrological processes over the Xijiang (West River) basin in South China. Three drought indices, namely standardized precipitation index (SPI), standardized runoff index (SRI), and soil moisture anomaly index (SMAI), are employed to examine the spatio-temporal and evolution features of drought events. SPI, SRI and SMAI represent meteorological drought, hydrological drought and agricultural drought, respectively. The results reveal that the drought severity depicted by SPI and SRI is similar with increasing timescales; SRI is close to that of SPI in the wet season for the Liu River basin as the high-frequency precipitation is conserved more by runoff; the time lags appear between SPI and SRI due to the delay response of runoff to precipitation variability for the You River basin. The case study in 2010 spring drought further shows that the spatio-temporal evolutions are modulated by the basin-scale topography. There is more consistency between meteorological and hydrological droughts for the fan-like basin with a converged river network. For the west area of the Xijiang basin with the high elevation, the hydrological drought severity is less than meteorological drought during the developing stage. The recovery of hydrological and agricultural droughts is slower than that of meteorological drought for basins with a longer mainstream.

  8. Gas hydrate formation and accumulation potential in the Qiangtang Basin, northern Tibet, China

    International Nuclear Information System (INIS)

    Highlights: • Qiangtang Basin is the biggest residual petroleum-bearing basin in Tibet Plateau. • The Late Triassic Tumen Gela Formation is the most important gas source rock. • Seventy-one potential anticline structural traps have been found. • A favorable geothermal condition for gas hydrate formation. • A large number of mud volcanoes were discovered in the basin. - Abstract: The Qiangtang Basin is the biggest residual petroleum-bearing basin in the Qinghai–Tibet Plateau, and is also an area of continuous permafrost in southwest China with strong similarities to other known gas-hydrate-bearing regions. Permafrost thickness is typically 60–180 m; average surface temperature ranges from −0.2 to −4.0 °C, and the geothermal gradient is about 2.64 °C/100 m. In the basin, the Late Triassic Tumen Gela Formation is the most important gas source rock for gas, and there are 34.3 × 108 t of gas resources in the Tumen Gela Formation hydrocarbon system. Seventy-one potential anticline structural traps have been found nowadays covering an area of more than 30 km2 for each individual one, five of them are connected with the gas source by faults. Recently, a large number of mud volcanoes were discovered in the central Qiangtang Basin, which could be indicative of the formation of potential gas hydrate. The North Qiangtang depression should be delineated as the main targets for the purpose of gas hydrate exploration

  9. Seismic tomography beneath the orogenic belts and adjacent basins of northwestern China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Three-dimensional velocity images of the crust and upper mantlebeneath orogenic belts and adjacent basins of the northwestern continent of China are reconstructed by seismic tomography, based on arrival data of P wave recorded in seismic networks in Xinjiang, Qinghai, Gansu of China and Kyrgyzstan. The velocity images of upper crust demonstrate the tectonic framework on the ground surface. High velocities are observed beneath orogenic belts, and low velocities are observed in the basins and depressions that are obviously related to unconsolidated sediments. The velocity image in mid-crust maintains the above features, and in addition low velocities appear in some earthquake regions and a low velocity boundary separates the western Tianshan Mts. from eastern Tianshan Mts. The orogenic belts and the northern Tibetan plateau have a Moho depth over 50 km, whereas the depths of the Moho in basins and depressions are smaller than 50 km. The velocity images of upper mantle clearly reveal the colliding relationship and location of deep boundaries of the continental blocks in northwestern China, indicating a weakness of the upper mantle structure of orogenic belts. The top depth of upper mantle asthenosphere varies from place to place. It seems shallower under the northern Tibetan plateau, Altay and Qilian Mts., and deeper under the Tarim and Tianshan regions. Hot mantle probably rose to the bottom of some orogenic belts along tectonic boundaries when continental blocks collided to each other. Therefore their dynamic features are closely correlated to the formation and evolution of orogenic belts in northwestern China.

  10. Coscinodon Cribrosus(Hedw.) Spruce(Musci: Grimmiaceae) Newly Recorded in Northwest China%小孔筛齿藓中国西部的新发现

    Institute of Scientific and Technical Information of China (English)

    买买提明·苏来曼

    2006-01-01

    In the past several years, the author studied the bryoflora of Xinjiang, Northwest China and found a series of new records there. Among them, Coscinodon cribrosus (Hedw.) Spruce and the genus Coscinodon are both firstly found in Northwest China.%通过中国新疆阿尔泰山脉藓类植物的调查研究,发现中国西部地区新记录种小孔筛齿藓(Coscinodon cribrosus (Hedw.) Spruce)这个新记录属和种的发现丰富了中国西北地区和新疆藓类植物的研究资料.在论文中讨论了该种的形态特征.

  11. Toward integrated environmental management for challenges in water environmental protection of Lake Taihu basin in China.

    Science.gov (United States)

    Wang, Qin'Geng; Gu, Gang; Higano, Yoshiro

    2006-05-01

    Lake Taihu is the third largest freshwater lake in China. It serves many social, economic, and ecological purposes in the drainage basin. Unfortunately, the water has been heavily polluted due to rapid industrialization and urbanization during the last two decades. Notwithstanding great efforts made so far to improve the water quality, the environmental situation is still far from being optimistic. The basin and the lake are facing a range of severe environmental challenges: rapid socio-economic development continues to place great pressures on the environment, current pollution control projects have many problems from the viewpoint of effectiveness and efficiency of their implementations, and the non-point sources of pollution such as agricultural fields, for which control is more difficult than for industrial point sources, have become the main contributors to serious eutrophication of the lake. Considering the characteristics of the environmental challenges and problems confronting the basin and the lake, we focus on integrated environmental management (IEM) as a promising and effective approach to overcome these predicaments. Current practices and problems of environmental management in the basin are examined, and potential future developments are discussed. Three aspects of the IEM are emphasized: institutional cooperation, public participation, and internalization of environmental externalities. We think these are the most critical for not only the basin but also for the whole of China to achieve a sustainable society. PMID:16508802

  12. The Early Miocene-Early Pliocene Vegetation and Climate Changes at the north to northwest Çankırı -Çorum Basin (Central Anatolian Plateau)

    Science.gov (United States)

    Atalar, Müge; Kováčová, Marianna; Sezgül Kayseri Ozer, Mine; Utescher, Torsten; Mazzini, Ilaria; Gliozzi, Elsa; Cosentino, Domenico

    2016-04-01

    The ALErT project targets on climate and tectonic hazards in the densely populated regions in the Central Anatolian Plateau (CAP), within the framework of the Marie Curie FP7-PEOPLE-2013-ITN program, The CAP extends in a wide area in between zone the Aegean extensional zone and Bitlis /Zagros compressional zone. Çankırı Basin (in the middle CAP) is a key to understand aridification plateau interior and it was a deep pelagic Basin from Late Cretaceous -Early Tertiary as a result of the closure of Neo- Tethyan till the Middle Eocene. North to south of the Çankırı Basin; the Plio - Quaternary Deǧim formation (fluvial deposits) consist of massive mudstones and sandstones and it unconformable overlies the Bozkır formation (lacustrine deposits). That is a Messinian succession mainly by a 200 m-thick cyclic sequence of continental gypsum layers, clays and sandy clays in gypsum with different thicknesses crops. Bozkır formation, the lower being the contact with the Süleymanlı formation. It is overlay the Tuǧlu formation with uncomformably, which is an Upper Miocene succession mainly composed of dark grey silty and organic rich clays. Following formation, which outcrops in the northwest of Çankırı basin, is Hançili formation. The unit is covered by grey sediments of the Hançili Formation, showing alternations of channel sandstones and clay stones over 100 m thick in Early - Middle Miocene in the Çankırı basin. In this study, samples were analyzed for biotic proxy data (palynology) to figure the paleo-environmental and paleoclimate changes. Additionally only for Bozkir formation (longest section in the study area) were sampled for geochemical (δ18O - δ13C isotopes analyses and CaCO3) analysis and the rest of the formations were interpreted using the previous study. In the most pollen spectra the herbs and shrubs prevail: in Deǧim formation (50%), in Bozkır formation (75%), in Süleymanlı formation (47%), in Tuǧlu formation (60%) and in Han

  13. Structure of the Dayangshu Basin in Northeast China Inferred from Magnetotelluric Data

    Science.gov (United States)

    Cao, J.; Sun, Y.; Li, X.; Chen, S.

    2005-12-01

    The Dayangshu basin is a NNE trending fault-bounded basin, located at longitude 123°21' - 125°38' east and latitude 47°55' - 50°59' north within the southern part of the Xingan fold system. It is one of the largest sedimentary basins in Northeast China with an area of 15,460 km2. The sedimentary rock in the basin is approximately 3,000 m thick, and is composed mainly of clastic rocks and volcanic rocks. The base of the basin consists mainly of Paleozoic low-grade metamorphic rocks. In the early 1990s, the Daqing Oilfield Company started petroleum exploration programs in the area. By the end of 1990s, gravity, magnetic, magnetotelluric (MT), and 2D seismic reflection measurements had been carried out in the basin and several prospects had been drilled. It has been determined that the majority, about 75%, of the basin is composed of volcanic rocks. However, the location and extent of the lava and main hydrocarbon source rock are still unclear. The distribution of these materials is very important for understanding the geological history and evaluating the petroleum resource capacity of the basin. The volcanic rocks within the basin are highly magnetic. The average susceptibility of the lava in the basin is about 0.18 SI units. It has been demonstrated that highly magnetic rocks significantly affect the MT response. By simultaneously inverting MT data for electric resistivity and magnetic susceptibility estimate, we develop a new approach for mapping magnetic strata. We apply the approach to the interpretation of MT data collected at 3,243 sites within the basin, and obtain a volcanic rock distribution model characterized by high susceptibility. The model shows that volcanic rocks are predominantly located at the boundary and middle of the basin. The volcanic rocks located at the middle of the basin cut the basin into southern, middle and northern sub-depressions. The hydrocarbon source rocks should be buried in the sub-depressions, and the lava close to the

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

    Science.gov (United States)

    Liu, Yu; Sun, Changfeng; Li, Qiang; Cai, Qiufang

    2016-01-01

    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. PMID:27509206

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

    Science.gov (United States)

    Liu, Yu; Sun, Changfeng; Li, Qiang; Cai, Qiufang

    2016-01-01

    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. PMID:27509206

  16. Airburst Impact Origin Hypothesis of Taihu Lake Basin in Southeast of China in Around 7000 Years ago

    Science.gov (United States)

    Xie, Z.; Zuo, S.

    2013-08-01

    The paper is to report investigation on unique morphology, occurrence, distribution, and mineralogy of siderite concretions found in Taihu Lake, Southeast of China, and discuss airburst impact origin hypothesis of Taihu Lake basin in ~7000 years ago.

  17. The verification of millennial-scale monsoon water vapor transport channel in northwest China

    Science.gov (United States)

    Li, Yu; Zhang, Chengqi; Wang, Yue

    2016-05-01

    Long-term changes of the Asian summer monsoon water vapor transport play a pivotal role in the variability of monsoon precipitation. Paleo-climate simulations have shown that there is an important monsoon vapor transport channel in western China. Previous studies mostly focused on the correlation between monsoon precipitation and intensity. Little research has been done on the verification of the water vapor channel. Compared with speleothem and lacustrine systems, the hydrological cycle of land surface sediments is more directly related to the monsoon water vapor. In this study, we used carbonate δ18O and organic matter δ13C of the surface eolian sediments from the piedmont of the northern Qilian Mountains to verify the monsoon water vapor on the Holocene millennial-scale. Two surface sedimentary sections were selected to study paleo-monsoon water vapor transport. Proxy data, including carbonate δ18O and organic matter δ13C of surface eolian sediments, as well as total organic matter and carbonate content were obtained from the two eolian sections. We also synthesized transient simulations of the CCSM3 and the Kiel climate models. The PMIP 3.0 project and TRACE isotopic simulations were also compared with the reconstructed monsoon water vapor transport. Our findings indicate that the strength of the Holocene Asian summer monsoon is consistent with the water vapor transport in western China that has significant impacts to long-term monsoon precipitation in northern China. This study verifies a significant millennial-scale correlation between the monsoon strength and monsoon water vapor transport intensity along the eastern Qinghai-Tibet Plateau.

  18. [Degradation characteristics, patterns, and processes of lakeside wetland in Napahai of northwest Yunnan Plateau, Southwest China].

    Science.gov (United States)

    Shang, Wen; Yang, Yong-Xing

    2012-12-01

    Two-way indicator species analysis (TWINSPAN) and canonical correspondence analysis (CCA) were employed to analyze the degradation characteristics, patterns, and processes of lakeside wetland in Napahai of northwest Yunnan Plateau. The plant communities in the lakeside wetland could be classified into four associations, according to the TWINSPAN results. The succession patterns of the plant community were represented by aquatic plant community --> swamp plant community --> swamp meadow plant community --> meadow plant community. During the processes of succession, the plant community coverage, density, Shannon diversity index, species richness, and plant aboveground biomass increased, whereas the community height decreased. The succession of the plant hydro-ecotypes followed the sequence of aquatic --> helophyte --> hygrophyte --> mesophyte. With the succession of the plant community, the wetland water quality indices salinity, alkalinity, and hardness decreased but ammonium nitrogen and total phosphorus concentrations increased, while total nitrogen and nitrate nitrogen concentrations showed no significant changes. Meanwhile, the soil pH and soil organic matter and total nitrogen contents decreased gradually, soil total phosphorous and potassium contents were increasing, whereas soil available phosphorous and potassium contents decreased after an initial increase. The CCA showed that the community species composition and structure were mainly affected by the wetland water gradient. The soil pH and total phosphorus content and the water total nitrogen and ammonium nitrogen concentrations had significant effects on the wetland plant species distribution and plant community succession. PMID:23479864

  19. Effects of Sand Dune Stabilization on the Spatial Pattern of Artemisia ordosica Population in Mu Us Desert, Northwest China

    Science.gov (United States)

    Zhang, Jiachen; Zhang, Yuqing; Fan, Dongqing; Qin, Shugao; Jia, Xin; Wu, Bin; Chen, Dong; Gao, Hao; Zhu, Linfeng

    2015-01-01

    Vegetation patterns are strongly influenced by sand mobility in desert ecosystems. However, little is known about the spatial patterns of Artemisia ordosica, a dominant shrub in the Mu Us desert of Northwest China, in relation to sand fixation. The aim of this study was to investigate and contrast the effects of sand dune stabilization on the population and spatial distribution of this desert shrub. Spatial autocorrelation, semi-variance analysis, and point-pattern analysis were used jointly in this study to investigate the spatial patterns of A. ordosica populations on dunes in Yanchi County of Ningxia, China. The results showed that the spatial autocorrelation and spatial heterogeneity declined gradually, and the distance between the clustered individuals shortened following sand dune fixation. Seedlings were more aggregated than adults in all stage of dune stabilization, and both were more aggregated on shifting sand dunes separately. Spatial associations of the seedlings with the adults were mostly positive at distances of 0–5 m in shifting sand dunes, and the spatial association changed from positive to neutral in semi-fixed sand dunes. The seedlings were spaced in an almost random pattern around the adults, and their distances from the adults did not seem to affect their locations in semi-fixed sand dunes. Furthermore, spatial associations of the seedlings with the adults were negative in the fixed sand dune. These findings demonstrate that sand stabilization is an important factor affecting the spatial patterns of A. ordosica populations in the Mu Us desert. These findings suggest that, strong association between individuals may be the mechanism to explain the spatial pattern formation at preliminary stage of dune fixation. Sand dune stabilization can change the spatial pattern of shrub population by weakening the spatial association between native shrub individuals, which may affect the development direction of desert shrubs. PMID:26102584

  20. Probabilistic forecasting of seasonal drought behaviors in the Huai River basin, China

    Science.gov (United States)

    Xiao, Mingzhong; Zhang, Qiang; Singh, Vijay P.; Chen, Xiaohong

    2016-01-01

    The Huai River basin is one of the major supplier of agricultural products in China, and droughts have critical impacts on agricultural development. Good knowledge of drought behaviors is of great importance in the planning and management of agricultural activities in the Huai River basin. With the copula functions to model the persistence property of drought, the probabilistic seasonal drought forecasting models have been built in the Huai River basin. In this study, droughts were monitored by the Standardized Precipitation Evapotranspiration Index (SPEI) with the time scales of 3, 6, and 9 months, and their composite occurrence probability has been used to forecast the seasonal drought. Results indicated that the uncertainty related to the predicted seasonal drought is larger when more severe droughts occurred in the previous seasons, and the severe drought which occurs in summer and autumn will be more likely to be persistent in the next season while the severe drought in winter and spring will be more likely to be recovered in the subsequent season. Furthermore, given the different drought statuses in the previous season, spatial patterns of the predicted drought events with the largest occurrence probability have also been investigated, and results indicate that the Huai River basin is vulnerable to the extreme drought in most parts of the basin, e.g., the severe drought in winter will be more likely to be persistent in spring in the central part of the southern Huai River basin. Such persistent drought events pose serious challenges for planning and management of agricultural irrigation, then results of the study will be valuable for the planning of crop cultivation or mitigation of the losses caused by drought in the Huai River basin, China.

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

    Science.gov (United States)

    Bei, Naifang; Li, Guohui; Huang, Ru-Jin; Cao, Junji; Meng, Ning; Feng, Tian; Liu, Suixin; Zhang, Ting; Zhang, Qiang; Molina, Luisa T.

    2016-06-01

    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 events in the basin under unfavorable synoptic conditions

  2. 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.

  3. 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.

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

    Science.gov (United States)

    Li, Y.; Kinzelbach, W.; Zhou, J.; Cheng, G. D.; Li, X.

    2012-05-01

    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.

  5. 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. PMID:24701387

  6. Effect of Nitrogen Management on Yield and Water Use Efficiency of Rainfed Wheat and Maize in Northwest China

    Institute of Scientific and Technical Information of China (English)

    DANG Ting-Hui; CAI Gui-Xin; GUO Sheng-Li; HAO Ming-De; L.K.HENG

    2006-01-01

    A field experiment with four treatments and four replicates in a randomized complete block design was conducted at the Changwu Experimental Station in Changwu County, Shaanxi Province, of Northwest China from 1998 to 2002. The local cropping sequence of wheat, wheat-beans, maize, and wheat over the 4-year period was adopted. A micro-plot study using 15N-labelled fertilizer was carried out to determine the fate of applied N fertilizer in the first year. When N fertilizer was applied wheat (years 1, 2 and 4) and maize (year 3) grain yield increased significantly (P < 0.05) (> 30%), with no significant yield differences in normal rainfall years (Years 1, 2 and 3) for N application at the commonly application rate and at 2/3 of this rate. Grain yield of wheat varied greatly between years, mainly due to variation in annual rainfall.Results of 15N studies on wheat showed that plants recovered 36.6%-38.4% of the N applied, the N remained in soil (0-40cm) ranged from 29.2% to 33.6%, and unaccounted-for N was 29.5%-34.2%. The following crop (wheat) recovered 2.1%-2.8% of the residual N from N applied to the previous wheat crop with recovery generally decreasing in the subsequent three crops (beans, maize and wheat).

  7. Assessment of heavy metal pollution in stream sediments for the Baoji City section of the Weihe River in Northwest China.

    Science.gov (United States)

    Fan, Shuanxi

    2014-01-01

    The concentrations of Pb, Zn, Cu, Cd and Cr in the stream sediment in the Baoji City section of the Weihe River, Northwest China, were determined to evaluate their contamination levels, spatial distribution and potential ecological risk. The average concentrations of the heavy metal sediments were 52.92 mg kg(-1) for Pb, 99.04 mg kg(-1) for Zn, 17.43 mg kg(-1) for Cu, 0.79 mg kg(-1) for Cd and 86.97 mg kg(-1) for Cr. The result of the assessment indicates that the pollution by Cd is serious, Zn and Cr are moderate and Cu is relatively light or unpolluted. The correlation analysis showed that the five heavy metals are significantly associated with each other. The hierarchical cluster analysis suggested that Zn, Cr and Pb might have identical anthropogenic and natural sources in stream sediments while Cu and Cd might have the same source in the Baoji City section of the Weihe River. PMID:25325554

  8. Retrieving historical ambient PM2.5 concentrations using existing visibility measurements in Xi'an, Northwest China

    Science.gov (United States)

    Shen, Zhenxing; Cao, Junji; Zhang, Leiming; Zhang, Qian; Huang, R.-J.; Liu, Suixin; Zhao, Zhuzi; Zhu, Chongshu; Lei, Yali; Xu, Hongmei; Zheng, Chunli

    2016-02-01

    Long term fine particulate matter (PM2.5) data are needed to assess air quality and climate issues, but PM2.5 data have only been monitored in the recent decade in Chinese cities. Considering strong correlations between PM2.5 and visibility, regression models can be useful tools for retrieving historical PM2.5 data from available visibility data. In this study, PM2.5 and visibility data are both available during 2004-2011 in Xi'an, a megacity in northwest China. Data from 2004 to 2007 were used to develop a regression model and those from 2008 to 2011 were used to evaluate the model. An exponential regression model was then chosen to retrieve the historical PM2.5 data from 1979 to 2003, which were then analyzed together with the measured data from 2004 to 2011 for long term trends. Seasonal PM2.5 increased from 1979 to 2011 with the fastest increase in winter and the slowest in summer. Annual average PM2.5 followed into three distinct periods with a slow decreasing trend from 1979 to 1996, a sharp increasing trend from 1997 to 2006, and a slow decreasing trend from 2007 to 2011. These increasing and decreasing trends are in agreement with the evolution of industrial development in Xi'an.

  9. The Vulnerability of Water Resources in Northwest China%中国西北水资源的脆弱性

    Institute of Scientific and Technical Information of China (English)

    刘春蓁

    2003-01-01

    The vulnerability of water resources in Northwest China were described in terms of the sensitivity and adaptability of water resource systems effected by climate change and human activities. Most measures that reduce the vulnerability are closely linked with decreasing the sensitivity of climate change or human activity. In other words, the interaction of climate factors and human activity may either exacerbate or mitigate the vulnerability of water resources. Studying both positive and negative events in terms of sustainable utilization of water resources in the past, may establish the sound strategic base in regulating further human activity. The knowledge and correct awareness of recent and future tendencies of hydro-climatic condition may serve as an imperative scientific base for taking such actions as: 1) undertaking structural and non-structural (e.g., policy, law, and forecasting) measures in a reasonable way; 2) coordinating and allocating both differences of time and space between inflow water and water use and between water yield area and water assumption area as well.

  10. Phylogenetic Diversity of Ammopiptanthus Rhizobia and Distribution of Rhizobia Associated with Ammopiptanthus mongolicus in Diverse Regions of Northwest China.

    Science.gov (United States)

    Zhao, Liang; Wang, Xinye; Huo, Haibo; Yuan, Guiji; Sun, Yali; Zhang, Dehui; Cao, Ying; Xu, Lin; Wei, Gehong

    2016-07-01

    Aiming to investigate the diversity and distribution of rhizobia associated with Ammopiptanthus, an endangered evergreen legume widely distributed in deserts, we characterized a total of 219 nodule isolates from nine sampling sites in Northwest China with different soil characteristics based upon restriction fragment length polymorphism (RFLP) analysis of 16S ribosomal RNA (rRNA) and symbiotic genes (nodC and nifH). Ten isolates representing different 16S rRNA-RFLP types were selected for further sequence analyses of 16S rRNA and four housekeeping genes. As results, nine genospecies belonging to the genera Ensifer, Neorhizobium, Agrobacterium, Pararhizobium, and Rhizobium could be defined among the isolates. The nodC and nifH phylogenies of 14 isolates representing different symbiotic-RFLP types revealed five lineages linked to Ensifer fredii, Ensifer meliloti, Rhizobium leguminosarum, Mesorhizobium amorphae, and Rhizobium gallicum, which demonstrated the various origins and lateral transfers of symbiotic genes between different genera and species. The rhizobial diversities of Ammopiptanthus mongolicus varied among regions, and the community compositions of rhizobia associated with A. mongolicus were significantly different in wild and cultured fields. Constrained correspondence analysis showed that the distribution of A. mongolicus rhizobia could be explained by available potassium content and that the assembly of symbiotic types was mainly affected by available phosphorus content and carbon-nitrogen ratio. PMID:27079453

  11. Alpine Ecosystems of Northwest Yunnan, China: an Initial Assessment for Conservation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Implementing conservation actions on-the-ground is not a straightforward process,especially when faced with high scientific uncertainty due to limited available information. This is especially acute in regions of the world that harbor many unique species that have not been well studied, such as the alpine zone of the Hengduan Mountains of Northwest Yunnan (NWY), a global biodiversity hotspot and site of The Nature Conservancy's Yunnan Great Rivers Project. We conducted a quantitative, but rapid regional-level assessment of the alpine flora across NWY to provide a broad-based understanding of local and regional patterns of the alpine flora, the first large-scale analysis of alpine biodiversity patterns in this region. Multivariate analyses were used to classify the major plant community types and link community patterns to habitat variables. Our analysis indicated that most species had small distributions and/or small population sizes. Strong patterns emerged with higher diversity in the more northern mountains, but beta diversity was high, averaging only 10% among sites. The ordinations indicated that elevation and geographic location were the dominant environmental gradients underlying the differences in the species composition among communities. The high beta diversity across the alpine of these mountains implies that conservation strategies ultimately will require the protection of large numbers of species over a large geographical area. However, prioritization should be given to areas where potential payoffs are greatest. Sites with high species richness also have a greater number of endemic species, and, by focusing efforts on these sites, conservation investments would be maximized by protecting the greatest number of unique species.

  12. 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.

  13. Drought analysis using multi-scale standardized precipitation index in the Han River Basin, China

    Institute of Scientific and Technical Information of China (English)

    Yue-ping XU; Sheng-ji LIN; Yan HUANG; Qin-qing ZHANG; Qi-hua RAN

    2011-01-01

    Regional drought analysis provides useful information for sustainable water resources management. In this paper, a standardized precipitation index (SPI) at multiple time scales was used to investigate the spatial patterns and trends of drought in the Han River Basin, one of the largest tributaries of Yangtze River, China. It was found that, in terms of drought severity, the upper basin of the Hart River is the least, while the growing trend is the most conspicuous; a less conspicuous growing trend can be observed in the middle basin; and there is an insignificant decreasing trend in the lower basin. Meanwhile, the impact of drought on the Middle Route of the South-to-North Water Transfer Project was investigated, and it is suggested that water intake must be reduced in times of drought, particularly when successive or simultaneous droughts in the upper and middle basins of the Han River Basin occur. The results can provide substantial information for future water allocation schemes of the South-to-North Water Transfer Project.

  14. Possible Future Climate Change Impacts on the Hydrological Drought Events in the Weihe River Basin, China

    OpenAIRE

    Fei Yuan; Mingwei Ma; Liliang Ren; Hongren Shen; Yue Li; Shanhu Jiang; Xiaoli Yang; Chongxu Zhao; Hao Kong

    2016-01-01

    Quantitative evaluation of future climate change impacts on hydrological drought characteristics is one of important measures for implementing sustainable water resources management and effective disaster mitigation in drought-prone regions under the changing environment. In this study, a modeling system for projecting the potential future climate change impacts on hydrological droughts in the Weihe River basin (WRB) in North China is presented. This system consists of a large-scale hydrologi...

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

    OpenAIRE

    Xin-e Tao; Hua Chen; Chong-yu Xu; Yu-kun Hou; Meng-xuan Jie

    2015-01-01

    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 in the Xiangjiang River Basin (XJRB) in China were analyzed. during the period from 1961 to 2010 was calculated with historical meteorological data using the FAO Penman-Monteith (FAO P-M) method, while during the period from 2011 to 2100 was downscaled from the Coupled Model Intercomparison Projec...

  16. Flash flood hazard mapping: a pilot case study in Xiapu River Basin, China

    OpenAIRE

    Da-wei Zhang; Jin Quan; Hong-bin Zhang; Fan Wang; Hong Wang; Xiao-yan He

    2015-01-01

    Flash flood hazard mapping is a supporting component of non-structural measures for flash flood prevention. Pilot case studies are necessary to develop more practicable methods for the technical support systems of flash flood hazard mapping. In this study, the headwater catchment of the Xiapu River Basin in central China was selected as a pilot study area for flash flood hazard mapping. A conceptual distributed hydrological model was developed for flood calculation based on the framework of t...

  17. Measurements of energy and water vapor fluxes over different surfaces in the Heihe River Basin, China

    OpenAIRE

    Liu, S.; Xu, Z.; Wang, W.; J. Bai; Jia, Z; Zhu, M.; Wang, J.

    2010-01-01

    We analyzed the seasonal variations of energy and water vapor fluxes over three different surfaces: irrigated cropland (Yingke, YK), alpine meadow (A'rou, AR), and spruce forest (Guantan, GT). The energy and water vapor fluxes were measured using eddy covariance systems (EC) and a large aperture scintillometer (LAS) in the Heihe River Basin, China, in 2008 and 2009. We also determined the source areas of the EC and LAS measurements with a footprint model for each site, and discussed th...

  18. Impact of global dimming on reference evapotranspiration in Hai River basin, China

    OpenAIRE

    Zhao, N.; Zeng, X.; Sun, H

    2015-01-01

    Global radiation can impact the surface energy balance and hydrological cycle. This study analysed changes in global radiation in Hai River basin, China during 1960 to 2012. Global radiation decreased significantly from 1960 to 1989 and increased from 1990 to 2012, which has been described as “from dimming to brightening”. Sunshine duration was used as a proxy index where radiation records were unavailable. Results showed that sunshine duration (for 45 stations) show a significant decreasing ...

  19. Network Analysis for a Better Water Use Configuration in the Baiyangdian Basin, China

    OpenAIRE

    Xufeng Mao; Donghai Yuan; Xiaoyan Wei; Qiong Chen; Chenling Yan; Liansheng He

    2015-01-01

    Nowadays, an increasing shortage of water resources intensifies the contradiction among different water-using sectors in the social-economic-ecological complex system. To adjust water used configuration in a holistic framework, a water use system (WUS) model was constructed with inclusive five water-using sectors including aquatic systems, primary industry, secondary industry, tertiary industry and resident consumption. The Baiyangdian Basin in Northern China was used as a case area. Six yea...

  20. Formation and Identification of Unresolved Complex Mixtures in Lacustrine Biodegraded Oil from Nanxiang Basin, China

    OpenAIRE

    2014-01-01

    A comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOFMS) method has been developed for the formation and identification of unresolved complex mixtures (UCMs) in lacustrine biodegraded oils that with the same source rock, similar maturity, and increasing degradation rank from Nanxiang Basin, China. Normal alkanes, light hydrocarbons, isoprenoids, steranes, and terpanes are degraded gradually from oil B330 to oil G574. The compounds in biodegraded oil ...

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

    OpenAIRE

    Xu, Z.; Zuo, D

    2014-01-01

    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...

  2. Spatio-Temporal Variations and Source Apportionment of Water Pollution in Danjiangkou Reservoir Basin, Central China

    OpenAIRE

    Pan Chen; Lan Li; Hongbin Zhang

    2015-01-01

    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 pollutio...

  3. 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.

  4. Simulations of Organic Aerosol Concentrations during Springtime in the Guanzhong Basin, China

    OpenAIRE

    Feng, Tian; Li, Guohui; Cao, Junji; Bei, Naifang; Shen, Zhenxing; Zhou, Weijian; Liu, Suixin; Zhang, Ting; Wang, Yichen; Tie, Xuexi; Molina, Luisa T.

    2016-01-01

    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 aerosols (POA) are assumed to be semi-volatile and photochemically reactive. Generally, the spatial patterns and temporal variations of the...

  5. 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

  6. Drought Trends and Temperature Influence in Zhanghe River Basin, China

    OpenAIRE

    Bakhtawar Wagan; Zhanyu Zhang; Feng Baoping; Si Han; Kabo-bah, Amos T.

    2015-01-01

    Our study area is one of the semiarid region of the China with under water stress condition that causes economic damage. The main objective of this study is to apply standardized precipitation evapotranspiration index (SPEI) and to use linear regression to calculate drought conditions in the study area. For this purpose, data from 1980 to 2010 was analyzed at different (1, 6, 12, and 24 months) time scales. Results depicted both dry and wet periods in the study area; occurrence of dry span wi...

  7. Prevalence, Risk Factors and Multilocus Genotyping of Giardia intestinalis in Dairy Cattle, Northwest China.

    Science.gov (United States)

    Zhang, Xiao-Xuan; Tan, Qi-Dong; Zhao, Guang-Hui; Ma, Jian-Gang; Zheng, Wen-Bin; Ni, Xiao-Ting; Zhao, Quan; Zhou, Dong-Hui; Zhu, Xing-Quan

    2016-07-01

    Giardia intestinalis is a cosmopolitan protozoan parasite that can infect a range of animals, including dairy cattle. As information regarding the prevalence and genotyping of G. intestinalis infection in dairy cattle in northwestern China is limited, 2,945 feces samples from 1,224 dairy cattle in Gansu Province and from 1,614 in Ningxia Hui Autonomous Region (NXHAR) were examined between December 2012 and March 2014. The overall prevalence of G. intestinalis was 3.63% (107/2,945), with 2.63% and 4.38% in Gansu and NXHAR, respectively. Logistic regression analysis showed region, age and season to be significant risk factors for G. intestinalis infection. Assemblage analysis identified 106 assemblage E and one assemblage A at the triose phosphate isomerase (tpi) locus in this study. Intravariations were also detected at tpi, glutamate dehydrogenase (gdh) and beta giardin (bg) loci within assemblage E, showing seven, three, and five new subtypes, respectively. Moreover, 13 new multilocus genotypes (E20-E32) were observed in assemblage E. Effective strategies and measures should be taken to prevent and control giardiasis in Gansu and NXHAR. PMID:26729604

  8. Millennium tree-ring reconstruction of drought variability in the eastern Qilian Mountains, northwest China

    Science.gov (United States)

    Gou, Xiaohua; Deng, Yang; Gao, Linlin; Chen, Fahu; Cook, Edward; Yang, Meixue; Zhang, Fen

    2015-10-01

    Knowledge of natural long-term drought variability is essential for water resource management and planning, especially in arid and sub-arid regions of the world. In the eastern Qilian Mountains of China, long-term drought variability based on high-resolution proxy records such as tree-ring data are still scarce to date. Here we present a new tree-ring chronology from the eastern Qilian Mountains which provides a valuable 1,002-year record (1009-2010 CE) of drought variability. The new reconstruction of June-July 5-month scale standardized precipitation and evapotranspiration index is the first millennium tree-ring estimate of past climate developed in the eastern Qilian Mountains. The record shows that this region has experienced several persistent droughts and pluvials over the past millennium, with significantly drier climate during the fifteenth century and dramatic wetting since the nineteenth century. The low frequency generally agrees with other nearby studies based on both tree-ring data and other proxy data.

  9. Closed basin brine evolution and the influence of Ca-Cl inflow waters : Death Valley and Bristol Dry Lake California, Qaidam Basin, China, and Salar de Atacama, Chile

    OpenAIRE

    Lowenstein, T. K.; Risacher, François

    2009-01-01

    Diagenetic-hydrothermal brines, here called "hydrothermal Ca-Cl brines," have compositions that reflect interactions between groundwaters and rocks or sediments at elevated temperatures. Hydrothermal Ca-Cl brines reach the surface by convection-driven or topographically driven circulation, and discharge as springs or seeps along fault zones to become important inflow waters in many tectonically active closed basins. Case studies from (1) Qaidam Basin, China, (2) Death Valley, California, (3) ...

  10. Drought assessment using a multivariate drought index in the Huaihe River basin of Eastern China

    Science.gov (United States)

    Li, Q.; Zeng, M.; Wang, H.; Li, P.; Wang, K.; Yu, M.

    2015-06-01

    The Huaihe River Basin having China's highest population density (662 persons per km2) lies in a transition zone between the climates of North and South China, and is thus prone to drought. Therefore, the paper aims to develop an appropriate drought assessment approach for drought assessment in the Huaihe River basin, China. Based on the Principal Component Analysis of precipitation, evapotranspiration, soil moisture and runoff, the three latter variables of which were obtained by use of the Xin'anjiang model, a new multivariate drought index (MDI) was formulated, and its thresholds were determined by use of cumulative distribution function. The MDI, the Standardized Precipitation Index (SPI) and the self-calibrating Palmer Drought Severity Index (sc-PDSI) time series on a monthly scale were computed and compared during 1988, 1999/2000 and 2001 drought events. The results show that the MDI exhibited certain advantages over the sc-PDSI and the SPI in monitoring drought evolution. The MDI formulated by this paper could provide a scientific basis for drought mitigation and management, and references for drought assessment elsewhere in China.

  11. 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

  12. 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.

  13. Holocene climate change and peatland dynamics in the Altai Mountains in Northwest China

    Science.gov (United States)

    Zhao, Y.; Yu, Z.; Li, Q.; Zhao, W.

    2013-12-01

    Here we present preliminary results from a peat-core record to investigate responses of upland vegetation and peatlands to Holocene climate change in the Altai Mountains. Chronology of a 650-cm-long peat core from the Iron Arshad Khan (IAK) peatland in the western Altai Mountains was controlled by 20 AMS dates on identifiable terrestrial macrofossils, covering the entire Holocene. Lithology results indicate that the peat accumulation initiated at 11 ka (1 ka =1000 cal BP), with a sharp increase in organic matter content to >80%. Plant macrofossil data show a sequence of changes from the peatlands dominated by Cyperaceae before 8.1 ka, to Cyperaceae and brown moss-dominated at 8-4.5 ka, Sphagnum and Cyperaceae-dominated at 4.5-2 ka, and to Cyperaceae-dominated again after 2 ka. Carbon accumulation rates were highest at >40 gC/m2/yr at 8.5-7 ka, more than doubled the Holocene average at the site. Pollen analysis shows the highest tree pollen (mainly from Picea) of up to 59% occurred at 8-6.4 ka, suggesting a warm and wet mid-Holocene 'optimum' climate in the region. Organic matter bulk density shows an increasing trend after 6.4 ka, suggesting increasing cumulative decomposition of accumulated peat. Our multi-proxy data indicate clear responses of peatland species composition, moisture conditions and carbon accumulation to regional climate change. The cooling and drying trend since the mid-Holocene was likely in response to the decrease in summer insolation and in westerly-induced precipitation. Furthermore, our results from this temperate highland peatland may shed new lights on understanding peatland carbon dynamics in northern Eurasia, including the largest peatland basin in West Siberia, as well as Holocene climate changes in central Asia.

  14. Composition, origin and weathering process of surface sediment in Kumtagh Desert, Northwest China

    Institute of Scientific and Technical Information of China (English)

    XU Zhiwei; LU Huayu; ZHAO Cunfa; WANG Xianyan; SU Zhizhua; WANG Zhenting; LIU Hongyi; WANG Lixin; LU Qi

    2011-01-01

    Kumtagh Desert is one of the eight biggest deserts in China,but poorly investigated before our interdisciplinary study because of the difficulty of access.In this paper,33 representative surface sediment samples were collected from the Kumtagh Desert and analyzed in the laboratory to obtain heavy mineral components and geochemical element contents.Results show that various kinds of heavy minerals are present in these samples,with high levels of epidote and hornblende.Si and AI take up a large part of chemical composition.Compared with the average composition of geochemical elements of the upper continental crust (UCC),except Si and Ca,all elements are depleted to a certain degree; Fe,Mg,Ca,P,Ti and Mn have high correlation coefficients in their contents.The mineral and geochemical composition of the Kumtagh Desert sediments have a similarity with that of rocks of Altyn Tagh Mountains,and the surface sediments of the alluvial/diluvial fans around the Altyn Tagh Mountains and that of the Taklamakan Desert,indicating that one major source of the Kumtagh Desert sediments is located in the Altyn Tagh Mountains.Alluvial deposits and lake sediments in Aqik valley and lower reaches of Shule River are prone to be eroded and transported by the strong northeasterly wind into the Kumtagh Desert,forming another source of the desert deposits.An A-CN-K ternary diagram shows that a weak degree chemical weathering by the loss of Na and K occurred in these sediments,whereas A-CNK-FM temary diagram suggests that Fe and Mg have undergone a significant chemical differentiation.Physical weathering processes cause easy erosion and enrichment in fine particles for mafic minerals,thus coarse desert sand particles can be relatively depleted in Fe and Mg.The mineral and geochemical composition of sediments in arid regions experiencing less chemical weathering are mostly affected by physical weathering.

  15. Occurrence and detection method evaluation of group B streptococcus from prenatal vaginal specimen in Northwest China.

    Science.gov (United States)

    Xie, Yun; Yang, JunLan; Zhao, Peng; Jia, Hui; Wang, Qi

    2016-01-01

    Sensitive and efficient detection of Group B Streptococcus (GBS) colonization in pregnant women is essential for prescription of prophylaxis at the time of delivery as GBS is an opportunistic pathogen known to cause infant mortality. In this report, two studies were conducted on the methods of GBS detection in Shaanxi province, China, a region lacking data for GBS detection and occurrence. For Study 1, 100 GBS culture-positive vaginal swabs were collected from 1,567 pregnant women for evaluation by direct latex agglutination test. In Study 2, 200 GBS vaginal swabs were evaluated by three culture methods (sheep blood agar (SBA), Columbia colistin-nalidixic agar (CNA), and selective carrot broth (SCB)) followed by analysis using a latex agglutination test. GBS was detected in 6.4 % of specimens in Study 1 and 10.5 % of specimens in Study 2. The results of the latex agglutination test in both studies were accurate with samples exhibiting high to moderate GBS growth, but the accuracy declined for samples with low GBS growth. The evaluation of culture methods for GBS detection revealed the sensitivity of SCB (95.2 %, p = 0.004) was significantly higher than that of the SBA medium (57.1 %). The sensitivity reported for SCB (95.2 %) was higher than CNA (76.0 %), but the difference was not statistically significant (p =0.078). These results indicate a selective broth, such as SCB, is ideal for accuracy at low growth levels, but a direct latex agglutination test could be used as an alternative for rapid detection of GBS in circumstances requiring immediate detection. PMID:26791082

  16. Quantitative Modelling of Multiphase Lithospheric Stretching and Deep Thermal History of Some Tertiary Rift Basins in Eastern China

    Institute of Scientific and Technical Information of China (English)

    林畅松; 张燕梅; 李思田; 刘景彦; 仝志刚; 丁孝忠; 李喜臣

    2002-01-01

    The stretching process of some Tertiary rift basins in eastern China is characterized by multiphase rifting. A multiple instantaneous uniform stretching model is proposed in this paper to simulate the formation of the basins as the rifting process cannot be accurately described by a simple (one episode) stretching model. The study shows that the multiphase stretching model, combined with the back-stripping technique, can be used to reconstruct the subsidence history and the stretching process of the lithosphere, and to evaluate the depth to the top of the asthenosphere and the deep thermal evolution of the basins. The calculated results obtained by applying the quantitative model to the episodic rifting process of the Tertiary Qiongdongnan and Yinggehai basins in the South China Sea are in agreement with geophysical data and geological observations. This provides a new method for quantitative evaluation of the geodynamic process of multiphase rifting occurring during the Tertiary in eastern China.

  17. Soil erosion assessment based on minimum polygons in the Yellow River basin, China

    Science.gov (United States)

    Ni, Jin-Ren; Li, Xiu-Xia; Borthwick, A. G. L.

    2008-01-01

    In the previous studies, a method was developed to assess soil erosion based on land use information. In this paper, we present another approach that uses environmental data to assess soil erosion. A soil erosion characteristic index EI is proposed, and its value is derived using the Analytic Hierarchy Process (AHP) technique based on standardized environmental information stored in minimum polygons that tile the erodible area under consideration. The approach is applied to a case study of the Yellow River basin, north China, where serious erosion is occurring. To represent different grades of soil erosion, the range of EI is divided into six levels according to standard grades of soil erosion intensity. The application indicates that the method deals properly with data scarcity, with the results giving a satisfactory representation of the characteristics of soil erosion in the Yellow River basin. The spatial-temporal distribution of EI in the Yellow River basin is predicted, and the results interpreted to give the long-term trend and state of soil depletion. Comparisons are given between EI and surveyed soil erosion zoning maps for the Yellow River basin at the end of the 1980s and 1990s. The output reliability and the approach applicability in smaller spatial scales are investigated in a case study of Zhifanggou basin.

  18. Palaeoclimatic evolution during Eocene and its influence on oil shale mineralisation, Fushun basin, China

    Science.gov (United States)

    Meng, Qingtao; Liu, Zhaojun; Bruch, Angela A.; Liu, Rong; Hu, Fei

    2012-02-01

    The Fushun basin is a small, explored, coal and oil shale-bearing, Cenozoic fault basin in the Liaoning Province, northeast China. The basin mainly consists of Eocene swamp to lacustrine deposits of the Guchengzi to Xilutian Formation, and contains the biggest opencast oil shale mine in Asia. This mine has provided an ideal opportunity to undertake palaeoclimate reconstruction in this basin based on a single geological profile and the analyses of 93 samples, using various approaches, namely field geological observation, clay mineralogical and geochemical (Sr/Ba, Sr/Cu, stable C and O isotope) analyses, all of which were compared with palaeobotanical data. The Eocene climate of Fushun basin evolved from warm temperate to north subtropical, and generally changed from warm humid to subhumid-semiarid. Paleoclimatic and geochemical parameters shows that the very warm and humid climate during Jijuntun Formation increased the initial productivity of lake water, and caused a steady stratification of the lake water, then caused oxygen lack in the bottom of water. Productivity of the lake provides the mean origin of organic matters for oil shale formation, and steady anoxic environment is beneficial for the conservation of organic matters.

  19. Desertification and Sustainable Development of the Heihe River Basin in Arid Northwestern China

    Institute of Scientific and Technical Information of China (English)

    Qi Shanzhong; Luo Fang

    2004-01-01

    The Heihe River Basin of northwestern China is one of several areas severely affected by desertification. This article outlines the status of desertification in this basin. There are mainly 5 types of desertification in the Heihe River Basin, namely soil and water erosion, sandy desertification, soil aridization, soil salinization and vegetation degradation.Among the 5 types of desertification, the main desertification type is sandy desertification with an area of 10 771.97 km2; Second type is soil salinization with an area of 10 591.82 km2; Next to the soil salinization is the type of soil and water erosion with an area of 5 747.68 km2 and the other types of desertification in the Heihe River Basin are soil aridization with just area of 1 369.96 km2 and vegetation degradation type with an area of 1 490.48km2 respectively. Both natural and man-made factors are responsible for the causes of desertification development, among which the latter is the main driving force for desertification in the basin.

  20. Abnormal overpressure distribution and natural gas accumulation in foreland basins, Western China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Abnormal overpressure occurs in the foreland basins of Kuqa, South Junggar and West Sichuan in China. The pressure coefficients are high. Overpressure exists in wide areas and various strata. The layers of overpressure have a very close relationship with lithology, and the area of overpressure is controlled by the piedmont depression. The mechanisms of overpressure formation in the Kuqa and South Junggar Depression include disequilibrium compaction and tectonic compression; the importance of these two factors varies in different basins and in different stages of the same basin. Different models of gas accumulation are established to explain the relationship between overpressure distribution and gas pool formation, and the influence of overpressure on the gas pools. These models include: (ⅰ) the violent tectonic movement leads to the pool formation in overpressure belt (Kela-2 gas field in Kuqa); (ⅱ) the pressure releases at shallow part and the gas pool forms in late time (Hutubi gas field in southern Junggar Basin); (ⅲ) through the pressure transfer the gas migrates and accumulates (Xinchang gas field in Western Sichuan Basin).

  1. The origin of groundwater in Zhangye Basin, northwestern China, using isotopic signature

    Science.gov (United States)

    Chen, Jiansheng; Liu, Xiaoyan; Sun, Xiaoxu; Su, Zhiguo; Yong, Bin

    2014-03-01

    Zhangye Basin, in arid northwestern China, has recently been repeatedly flooded by rising groundwater. Isotope signatures of sampled waters gained insight into the recharge source of the groundwater. The summer Heihe River water and most of the spring water in Zhangye and Yongchang basins plotted above the global meteoric water line (GMWL) on the δ18O-δD plot. The spring water had R/Ra ratio >1, low TDS and high tritium, which indicates origin from Qilian Mountain glacier meltwater. The groundwater of Qilian Mountains was transported to the Hexi Corridor (in which Zhangye Basin is located) through underground fault zones. Additionally, some of the groundwater in the alluvial plain, and all spring water surrounding Zhangye Basin, plotted below the GMWL on the δ18O-δD plot along an evaporation line, and had R/Ra ratio < 1 and high TDS. It is proposed that the Tibetan rivers or lakes source the Hexi Corridor groundwater through either the NE-trending or NW-trending buried fault zones. The isotopic signatures presented as part of this study rule out the conventional viewpoint that groundwater of the Zhangye Basin was recharged by local precipitation and infiltration of Heihe River water on the alluvial plain.

  2. Tree-Ring Dating of the Reshui-1 Tomb in Dulan County, Qinghai Province, North-west China

    Science.gov (United States)

    LI, M.; Xuemei, S.; Yin, Z. Y.; Xu, X.

    2015-12-01

    Tuyuhun and Tubo were two important states that thrived in north-western China during AD 311-900 in parallel with the Han Chinese dynasties of Sui and Tang periods. The Reshui Tomb Cluster located in Dulan County of the north-eastern Tibetan Plateau is an important cultural relic of the Tuyuhun-Tubo age. The official excavations of the Reshui tombs were regarded as top events in archaeology in the 1980s and 1990s in China. The Reshui-1 Tomb is the largest one among the tombs in the area. Since its excavation, there have been debates on whether the owner of the tomb belonged to the Tuyuhun or Tubo ethnicity. Therefore, accurately dating the Reshui-1 Tomb has a critical place in studying the Tubo and Tuyuhun histories. We collected 7 discs and 11 increment cores of Qilian juniper (Juniperus przewalskii Kom.) from the exposed and fallen beams of the roof of the Reshui-1Tomb. The lengths of the 16 tree-ring records are between 69 and 152 years. Based on a previously developed master dating chronology using Qilian juniper samples from the eastern Qaidam Basin, the calendar dates of the 16 specimens were determined by the COFECHA program and visual dating procedure. The average inter-series correlation among the dated sample series is 0.696, indicating good quality of cross-dating. The year of the outermost rings is AD 715 for the 7 discs and 4 out of the 9 increment cores. Moreover, the ring-width variations of the samples are consistent with the existing chronologies from the region. The presence of late-wood of AD 715 in the samples indicated that the Reshui-1 Tomb was completed in late AD 715 or early 716, which means that the Reshui-1 Tomb was finished in the Tubo age. This date provides direct evidence for archaeologists to determine the owner's ethnicity and identify of the Reshui-1 Tomb.

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

    Directory of Open Access Journals (Sweden)

    Guoyong Ding

    Full Text Available BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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

  4. Relationship between species richness and biomass on environmental gradient in natural forest communities on Mt. Xiaolongshan, northwest China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We analyzed the relationship between species richness and biomass in natural forest communities at two similar sites on Mt. Xiaoiongshan, northwest China. At both sites, a wide range of tree layer biomass levels was available by local biomass estima-tion models. In order to identify underlying mechanism of the species richness-biomass relationship, we included different water resource levels and number of individuals in each plot in our analysis. We sampled 15 and 20 plots (20 m x 20 m), respectively, at both two sites. These plots were sampled equally on the sunny slope and the shady slope. Species richness, number of individuals of each species and diameter at breast height (DBH) as a substitute of biomass of tree layer were recorded in each sample. At one site,the relationship between species richness and biomass was significant on the sunny slope, and this relationship disappeared on the shady slope due to more environmental factors. The relations between species richness and number of individuals and between num-ber of individuals and biomass paralleled the species richness-biomass relation on both slopes. The difference in number of individu-als-biomass relationships on the sunny slope and the shady slope revealed "interspecific competitive exclusion" even though the species richness-biomass relationships were not hump-shaped. At the other site, species richness was not related to biomass or to number of individuals. Our study demonstrated the importance of environmental stress and succession of community in the under-standing of species diversity-productivity patterns.

  5. Evaluation of Penman-Monteith model applied to a maize field in the arid area of Northwest China

    Directory of Open Access Journals (Sweden)

    W.-Z. Zhao

    2010-01-01

    Full Text Available The Penman-Monteith (P-M model has been applied to estimate evapotranspiration in terrestrial ecosystem widely in the world. As shown in many studies, bulk canopy resistance is an especially important factor in the application of P-M model. In this study, the authors used the Noilhan and Planton (N-P approach and Jacobs and De Bruin (J-D approach to express the bulk canopy resistance. The application of P-M mode to a maize field with two approaches in the arid area of Northwest China was evaluated by the measured half-hourly values from the eddy covariance system. The results indicate that the N-P approach underestimates slightly the bulk canopy resistance, while the J-D approach overestimates that. The estimation of bulk canopy resistance with N-P approach was then better and more consistent than that with J-D approach during the entire maize growing season. Correspondingly, the P-M model with J-D bulk canopy resistance slightly underestimated the latent heat flux throughout the maize growing season, but overestimated the latent heat flux during the dry period of the soil as compared to that with N-P approach. The good fitness of the simulated latent heat flux by the P-M model with N-P bulk canopy resistance approach to the measured one at a half-hour time step demonstrates the application of the approach is reasonable in the relative homogenous and not drought-stressed maize fields of the arid areas during the entire growing season. Further researches are discussed on enhancing the field observation, taking the correction for atmospheric stability into estimating aerodynamic resistance, to improve the performance of P-M model to simulate evapotranspiration in the cropped fields.

  6. An Assessment of Storage Terms in the Surface Energy Balance of a Subalpine Meadow in Northwest China

    Institute of Scientific and Technical Information of China (English)

    WANG Runyuan; ZHANG Qiang

    2011-01-01

    The heat storage terms in the soil-vegetation-atmosphere system may play an important role in the surface energy budget. In this paper, we evaluate the heat storage terms of a subaipine meadow based on a field experiment conducted in the complex terrain of the eastern Qilian Mountains of Northwest China and their impact on the closure of the surface energy balance under such non-ideal conditions. During the night,the average sum of the storage terms was -5.5 W m-2, which corresponded to 10.4% of net radiation. The sum of the terms became positive at 0730 LST and negative again at about 1500 LST, with a maximum value of 19 W m-2 observed at approximately 0830 LST. During the day, the average of the sum of the storage terms was 6.5 W m-2, which corresponded to 4.0% of net radiation. According to the slopes obtained when linear regression of the net radiation and partitioned fluxes was forced through the origin, there is an imbalance of 14.0% in the subalpine meadow when the storage terms are not considered in the surface energy balance. This imbalance was improved by 3.4% by calculating the sum of the storage terms. The soil heat storage flux gave the highest contribution (1.59%), while the vegetation enthalpy change and the rest of the storage terms were responsible for improvements of 1.04% and 0.77%, respectively.

  7. An Assessment of Storage Terms in the Surface Energy Balance of a Subalpine Meadow in Northwest China

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The heat storage terms in the soil-vegetation-atmosphere system may play an important role in the surface energy budget.In this paper,we evaluate the heat storage terms of a subalpine meadow based on a ficld experiment conducted in the complex terrain of the eastern Qilian Mountains of Northwest China and their impact on the closure of the surface energy balance under such non-ideal conditions.During the night, the average sum of the storage terms was -5.5 W m~(-2),which corresponded to 10.4%of net radiation.The sum of the terms became positive at 0730 LST and negative again at about 1500 LST,with a maximum value of 19 W m~(-2) observed at approximately 0830 LST.During the day,the average of the sum of the storage terms was 6.5 W m~(-2),which corresponded to 4.0%of net radiation.According to the slopes obtained when linear regression of the net radiation and partitioned fluxes was forced through the origin,there is an imbalance of 14.0%in the subalpine meadow when the storage terms are not considered in the surface energy balance.This imbalance was improved by 3.4%by calculating the sum of the storage terms.The soil heat storage flux gave the highest contribution(1.59%),while the vegetation enthalpy change and the rest of the storage terms were responsible for improvements of 1.04%and 0.77%,respectively.

  8. Post-Orogenic Granites in Pingwu Region, Northwest Sichuan: Evidence for North China Block and Yangtze Block Collision during Triassic

    Institute of Scientific and Technical Information of China (English)

    Pei Xianzhi; Li Zuochen; Ding Saping; Feng Jianyun; Li Ruibao; Sun Yu; Zhang Yafeng; Liu Zhanqing

    2009-01-01

    The Nanyili (南一里), Laohegou (老河沟), and Shaiziyan (筛子岩) granitic intrusions are located in the southern margin of the Bikou (碧口) block in Pingwu (平武) area, Northwest Sichuan (四川). The petrography and geochemical characteristics of the granitic intrusions as well as their source and tectonic settings are reported and discussed in this article. The Laohegou and Shaiziyan granites are with high SiO2 (69.89 wt.%-73.05 wt.%) and Al2O3 contents, and A/CNK=1.04-1.12. They are typi-cal strongly peraluminous granites, with supersaturation in Al and Si. The abundance of ∑REE varies in the range of (33.13-89.12)×106. The rocks show an LREE enrichment pattern and obvious Eu nega-tive anomaly. The trace element geochemistry is characterized evidently by a negative anomaly of Ta, Nb, Ti, etc. and a positive anomaly of Rb, Ba, Sr, etc.. Zircons of the Nanyili granite have higher Th/U ratios, and their CL images have internal oscillatory zoning, suggesting that the zircons of the samples are igneous in origin. The LA ICP-MS zircon U-Pb isotopic concordia diagram yields an age of 223.1±2.6 Ma (MSWD=1.4), which indicates that the granodiorite intrusions formed in the early Late Triassic. The Nanyili, Laohegou, and Shaiziyan granites have the characteristics of post-eollisional granites and are regarded as post-orogenic granites. Thus, the granite intrusions are interpreted as syn-collisional granites that resulted from the crustal thickening caused by the collisions between the North China plate and the Yangtze plate during the Indosinian. The granitic intrusions formed in a transitional environment from syn- (compres-slonal environment) to post-collision (extensionalenvironment).

  9. A Comparison of the Physical and Optical Properties of Anthropogenic Air Pollutants and Mineral Dust over Northwest China

    Institute of Scientific and Technical Information of China (English)

    王鑫; 浦伟; 史晋森; 闭建荣; 周天; 张雪荣; 任勇

    2015-01-01

    Emissions of mineral dust and its mixing with anthropogenic air pollutants aff ect both regional and global climates. Our fi eldwork in late spring 2007 (April 25–June 15) measured the physical and optical properties of dust storms mixed with local air pollutants at a rural site about 48 km southeast of central Lanzhou. Levels of air pollutants and aerosol optical properties were observed during the experiment, with concentrations of NOx (6.8 ± 3.3 ppb, average ± standard deviation), CO (694 ± 486 ppb), SO2 (6.2 ± 10 ppb), O3 (50.7 ± 13.1 ppb), and PM10 (172 ± 180 µg m−3), and aerosol scattering coeffi cient (164 ± 89 Mm−1; 1 Mm = 106 m) and absorption coeffi cient (11.7 ± 6.6 Mm−1), all much lower than the values observed during air pollution episodes in urban areas. During a major dust storm, the mass concentration of PM10 reached 4072 µg m−3, approximately 21-fold higher than in non-dust storm periods. The mixing ratios of trace gases declined noticeably after a cold front passed through. The observed CO/SO2 and CO/NOx ratios during air pollution episodes were 4.2–18.3 and 13.7–80.5, respectively, compared with the corresponding ratios of 38.1–255.7 and 18.0–245.9 during non-pollution periods. Our investigations suggest that dust storms have a signifi cant infl uence on air quality in areas far from their source, and this large-scale transport of dust and air pollutants produces major uncertainties in the quantifi cation of the global eff ects of emissions over Northwest China.

  10. Improved cloud mask algorithm for FY-3A/VIRR data over the northwest region of China

    Directory of Open Access Journals (Sweden)

    X. Wang

    2012-11-01

    Full Text Available The existence of various land surfaces has always been a difficult problem for researchers who study cloud detection using satellite observations, especially over bright surfaces such as snow and desert. To improve the cloud mask result over complex terrain, an unbiased daytime cloud detection algorithm for the Visible and InfRared Radiometer (VIRR on board the Chinese FengYun-3A polar-orbiting meteorological satellite is applied over the northwest region of China. Based on the statistical seasonal threshold tests, the algorithm consists of six main channels centered on the wavelengths of 0.63, 0.865, 10.8, 1.595, 0.455, and 1.36 μm. The combination of the unbiased algorithm and the specific threshold tests for special surfaces has effectively improved the cloud mask results over complex terrain and decreased the false identifications of clouds. The visual images over snow and desert adopting the proposed scheme exhibit better correlations with true-color images than do the VIRR official cloud mask results. The validation with the Moderate Resolution Imaging Spectroradiometer (MODIS cloud mask product shows that the probability of detection for clear-sky regions over snow of the new scheme has increased nearly five times over the official method, and the false-alarm ratio for cloudy areas over desert has reduced by half compared with the official result. With regard to comparisons between ground measurements and cloud mask results, this approach also provides acceptable correspondence with the ground observations except for some cases, which are mainly obscured by cirrus clouds.

  11. Relationship of nitrate isotopic character to population density in the Loess Plateau of Northwest China

    International Nuclear Information System (INIS)

    Highlights: • Investigated nitrate isotopic composition in Xi’an. • δ15N–NO3- enrich process is mainly caused by the anthropogenic activity. • δ15N–NO3- value useful for tracing nitrate source. • δ15N–NO3- value and population density show a significant logarithmic correlation. - Abstract: Nitrate pollution of groundwater is an increasingly serious anthropogenic problem. In this study, the hydrogeochemistry of major ions and stable isotope ratios of NO3- in groundwater were determined to identify the contamination sources and chemical transformation processes occurring in the shallow groundwater of Xi’an, the capital of Shaanxi province, NW China. Of a total of 32 groundwater samples, 31% had NO3-–N concentrations exceeding the accepted drinking water limit of 10 mg-N L−1. Most of these samples were from the urban center of the study area, while samples with <10 mg-N L−1 were mainly from suburban areas. Combined with information on NO3- and Cl−, the variation in isotopes of NO3- in the groundwater suggest a mixing of multiple NO3- sources in areas on the urban/suburban border. By determining rainwater and river water NO3- isotopic values, the groundwater recharge mode can be deduced for Xi’an city. Chemical fertilizers and nitrification of N-containing organic materials contribute NO3- to suburban groundwater, while sewage effluent and nitrification dominate NO3- distribution in urban groundwater. Nitrification from organic soil N, manure and sewage was significant in some sampling areas, and NO3- isotopic values from groundwater in Xi’an indicated that the effects of denitrification were not an obvious contributor. Thus, the δ15N–NO3- enrichment process is mainly caused by the intense anthropogenic activity in the city center. From the urban center to suburban areas, the mean δ15N–NO3- values varied from +16.4‰ to +5.4‰, and the mean NO3-–N concentrations varied from 28.0 mg L−1 to 4.0 mg L−1. In particular, the

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

    Directory of Open Access Journals (Sweden)

    Liping Li

    Full Text Available 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

  13. Tectonic Subsidence Analysis of the Pearl River Mouth Basin, Northern South China Sea

    Science.gov (United States)

    Tang, X.; Huang, S. S. X. E. C.; Zhuang, W.; LIU, Z.; Duan, W.; Hu, S.

    2015-12-01

    The Pearl River Mouth Basin (PRMB hereafter) in the northern margin of the South China Sea has attracted great attention not only because of its special tectonic location but also for its abundant hydrocarbon resources. Tectonic evolution controls the petroleum geological condition of hydrocarbon-bearing basins. Efforts have been made to understand the tectonic evolution of this basin. However, many issues about the tectonic features and the evolution process of this basin, such as the age of the breakup unconformities and the anomalously accelerated subsidence during the post-rifting stage, remain controversial. Here we employ tectonic subsidence analysis of sedimentary basins, a technique of removing isostatic loading and compaction effects by back-stripping, to investigate the tectonic controls on the basin formation of the PRMB. We performed the analysis on 4 drill wells and 43 synthetic wells constructed based on recently acquired seismic profiles. The result shows that tectonic subsidence in the eastern sags of the PRMB began to decrease at ~30Ma while in the western sags the onset was ~23.8Ma. This suggests that the break-up time i.e. the end of rifting in the PRMB is earlier in the eastern sags than in the western sags. Abnormally accelerated tectonic subsidence occurred between 17.5-16.4Ma during the post-rifting stage, at an average subsidence rate as high as 301.9m/Ma. This phenomenon discriminates the PRMB from the category of classical Atlantic passive continental marginal basins, of which the tectonic subsidence during the post-rifting stage decays exponentially. The main objective of this paper is to provide insights into the geological and geodynamic evolution of the PRMB. The result bears significance to hydrocarbon exploration in this region.

  14. The mechanics of continental extension in Qiongdongnan Basin, northern South China Sea

    Science.gov (United States)

    Zhao, Zhongxian; Sun, Zhen; Wang, Zhenfeng; Sun, Zhipeng

    2015-09-01

    Located in the intersection of NE-trended rifted margin of South China Sea (SCS) and NW-oriented Ailao Shan-Red River Shear Zone (RRSZ), Qiongdongnan Basin shows significant differences in geological features from west to east, indicating different mechanics of continental extension. Based on the dense and updated multichannel seismic profiles, we disclose the characteristics of the remnant crystalline crust. Besides, we analyze the basin structures, calculate the stretching factors of upper and whole crust, and compute the syn-rift and post-rift unloaded tectonic subsidence along three selected transects in the west, middle and east of Qiongdongnan Basin. The crust thickness is 22 km on the northern and southern parts of Qiongdongnan Basin and thins gradually towards the central depression with two extremely thinned domains (factors of crust are 1.5-2 on both sides and increase remarkably towards the central depression (β > 2) with two extremely stretched domains (β > 9), of which one is in Ledong Sag in the west and another is in Baodao and Changchang Sags in the east. However, the mechanics of continental extension vary significantly from west to east. The simple shear dominates in the west, the pure shear dominates in the east, and it is intermediate between the two end members of simple shear and pure shear in the middle of Qiongdongnan Basin. The simple shear in the west of Qiongdongnan Basin is probably controlled by the left-lateral movement of RRSZ. The pure shear in the east is probably related to the Cenozoic rifting along the northern continental margin of SCS. The transitional zone in the middle of Qiongdongnan Basin is possibly the combined results of the left-lateral movement of RRSZ and the Cenozoic rifting along the northern continental margin of SCS.

  15. Recognition of relict Mesozoic Dongsha Basin in the northern margin, South China Sea and its implication

    Science.gov (United States)

    Yan, Pin; Wang, Yanlin

    2015-04-01

    The Pearl River Mouth Basin (PRMB) is dominated by NE-trending rift architecture produced mainly during Cenozoic Era. It comprises a series of grabens built up with thick Paleogene and thick Neogene sediments, up to 12000 m, and dividing basement highs composing Yanshanian granitic rocks. Though previously considered as one constituent part of PRMB in the southeast, Dongsha Basin displays major differences in sedimentary architecture and tectonic framework. Firstly, Dongsha Basin is characterized by a prominent angular unconformity, interpreted as a spectacular planation or rough erosion surface which separates the sediment column into two distinct parts. It is interpreted with accumulating seismic and drill data that the underlying strata comprise Early Cretaceous terrestrial, Jurassic marine and possibly Triassic sedimentary rocks totaling to 4~9 km thick, whereas the overlying strata are very thin (usually 0.5~1 km in whole) composing mainly Neogene sediments. The major sedimentary hiatus between them corresponds to the Late Cretaceous to mid-Miocene Epoch, well during the rifting to spreading process when the PRMB developed. Secondly, unlike the PRMB, the Dongsha Basin has suffered considerably less extension except its boundary areas, and actually remained as a relatively stable block though Cenozoic Era. Moreover, there are a few compressive open fold structures within the buried Mesozoic strata over the central Dongsha Basin. These folds trend in NNE and are characterized mostly by few minor growing upthrust faults with offsets in the order of few tens to hundreds meter. The upthrust faults dipped mostly southeastward against the northwestward subduction of paleo-Pacific plate as postulated in other previous study. The blind folds featured more like back-thrust growth tectonics, formed a broad NNE-SSW trending belt, obviously oblique to the trend of northern margin of the South China Sea and the PRMB as well. In a few recent models, the most prominent

  16. Mechanism of petroleum migration and accumulation in western China's superposed basins

    Institute of Scientific and Technical Information of China (English)

    Kang Yongshang; Li Peijun; Qi Xuefeng; Wen Yonghong; Li Shuijing

    2012-01-01

    In western China.most petroliferous basins are superposed due to their multi-periodic tectonic evolution,and the mechanisms of petroleum migration and accumulation are so complex that much more sophisticated methodologies are necessary for depiction of these mechanisms and identification of petroleum occurrences.For this purpose,in this article,a new methodology was formulated which includes:(1) vertical identification of petroleum migration and accumulation fluid dynamic systems in the superposed basins;(2) analysis of the effect of large scale regional faults and fault combinations on the fluids exchange between the vertically identified different systems;(3) analysis of petroleum migration and accumulation in each vertically identified system,and establishment of appropriate geological model of petroleum migration and accumulation for each vertically identified system.Using this methodology,the satisfactory results obtained in the Lunnan Uplift of Tarim Basin and Ludong Uplift of Jungar Basin case studies are:(1) existence of different vertical fluid dynamic systems in western China's superposed basins which are very necessary for understanding the mechanism of petroleum migration and accumulation;(2) in deep system,long-distance lateral petroleum migration and accumulation mainly take place along the long time exposed unconformity with weathered,fractured or karst reservoir rocks;(3) regional faults are the main conducts for fluids migration from deep system up to middle and/or upper systems.As to middle and/or upper systems,regional faults play a role of "petroleum source".Small faults within middle and/or upper systems conduct petroleum to carrier beds with less impeding force;(4) petroleum migrated from deep system vertically up to middle and/or upper systems will migrate laterally in carrier beds of these systems and accumulate to form pools near or far from faults.

  17. Drought Trends and Temperature Influence in Zhanghe River Basin, China

    Directory of Open Access Journals (Sweden)

    Bakhtawar Wagan

    2015-01-01

    Full Text Available Our study area is one of the semiarid region of the China with under water stress condition that causes economic damage. The main objective of this study is to apply standardized precipitation evapotranspiration index (SPEI and to use linear regression to calculate drought conditions in the study area. For this purpose, data from 1980 to 2010 was analyzed at different (1, 6, 12, and 24 months time scales. Results depicted both dry and wet periods in the study area; occurrence of dry span with different frequency and magnitude was increased over last decades (2000–2010 at most of the stations. Statistical results demonstrated that temperature was decreased in the 1st decade in most of stations but in two decades from 1990 to 2000 and 2001 to 2010, temperature was increased except in Changzhi station. These results could be a future reference for developing information programs about monitoring and early drought information, planning of existing reservoirs, and management of water resources under climate conditions.

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

    International Nuclear Information System (INIS)

    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− concentration of up to 14.1 mg/L), 44% of groundwater samples from the intermediate and 31% from the deep aquifers had F− concentrations above the WHO provisional drinking water guideline of 1.5 mg/L. Groundwater with high F− concentrations displayed a distinctive major ion chemistry: Na-rich and Ca-poor with a high pH value and high HCO3− 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− mobilization as well. Leakage of shallow groundwater and/or evaporite (gypsum and mirabilite) dissolution may be the major sources for F− in groundwater of the intermediate and deep aquifers. - Highlights: • High-F− groundwater widely occurs in Yuncheng Basin of northern China. • High-F− groundwater is Na and HCO3-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

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

    Science.gov (United States)

    Xu, Z.; Zuo, D.

    2014-09-01

    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.

  20. Tertiary Sea Level Changes and Sequence Stratigraphic Framework in East China Sea Shelf Basin

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The East China Sea shelf basin is a key area for setting up the sea level changes of Cenozoic in the West Pacific. Based upon the characteristics of seismic reflection, the analysis of sequence stratigraphy and depositional system, the high-resolution chronostratigraphic framework has been set up by using the data of micropaleontologic biozone fossils. The relative sea level change curve has been set up by combining analysis of paleoecology, genetic facies, specific sedimentary structures and on-lap recognized from the seismic profiles with study of geochemical characteristics. There are 4 2nd-order basin cycles showing the long-term sea level changes, and 22 3rd-order cycles showing short-term ones with relative changing ranges of 0-150 m. Transgression and regression showing long-term sea level changes bear asymmetric feature, which indicates that the speed of transgression is faster than that of regression. There are a lot of differences when compared with Haq's curve. The sequence stratigraphic framework has also been set up and 3 tectonic sequences, 7 supersequences and 19 sequences have been subdivided for Tertiary in the East China Sea shelf basin. On the basis of detailed analysis of genetic facies and log facies, 9 sedimentary systems, 20 depositional assemblages and many genetic facies have also been recognized and investigated. Based on the studies mentioned above, the favorable source and reservoir facies of gas and petroleum are indicated.

  1. Genetic Improvement of Agronomic Water Use Efficiency of Wheat in Northwest China

    International Nuclear Information System (INIS)

    The five North-western provinces of China (Shaanxi, Gansu, Ningxia, Qinhai and Xinjiang) are located in arid or semiarid areas, where evaporation is 4- to 10-fold higher than precipitation. The serious deficiency of water results in poor yields and low profits from agricultural production. Grain production in the limited irrigated areas is seriously threatened by the continuous water decline in the Yellow River. Wheat is the major crop cultivated in the region. Therefore, breeding wheat varieties resistant to drought with increased water use efficiency (WUE) is one of main strategies for increasing food security and stabilizing farmers' incomes. The purpose of the research was to study the relationships between carbon isotope discrimination (CID, Δ13C or Δ) and yield, agronomic WUE and other related traits in wheat, and to select high WUE wheat varieties adapted to different ecological environments. We evaluated the genetic variation of Δ, studied the relationships between Δ and yield, developed populations from progenitors which contrasted in leaf and kernel-Δ, and studied the genetics of Δ in wheat from 2004 to 2006. In 2004, 32 bread wheat cultivars were planted in four locations, including two rain fed sites (Guyuan and Penyang) and two limited irrigated sites (Yinchuan and Huinong) to study the genetic variation in Δ. In 2005, 20 bread wheat genotypes were studied for the relationship between Δ and yield, and the varieties with contrasting Δ values were selected to make crosses in three locations. In 2006, 2007 and 2008, F3, F4, F6 progenies and stabilized genotypes were planted in Yinchuan (limited irrigation) and in Guyuan (rain fed). The genetics of Δ were studied in 2006, 2007 and 2008. Correlations between Δ and yield were studied in progenies and stabilized genotypes in 2008. Significant variation in Δ was found across genotypes, locations and years. The Δ of local varieties was significantly lower than that of improved varieties and

  2. Soil freezing and thawing processes affected by the different landscapes in the middle reaches of Heihe River Basin, Gansu, China

    Science.gov (United States)

    Yi, Jun; Zhao, Ying; Shao, Ming'an; Zhang, Jianguo; Cui, Lele; Si, Bingcheng

    2014-11-01

    An understanding of soil freezing and thawing processes in seasonally frozen soil is important for many agricultural and environmental issues, especially under different landscapes in terms of land use and climate change. In this study, sandy soil behavior under soil freezing and thawing cycles were investigated under three typical landscapes (i.e., farmland, forest, and desert) in the middle reaches of the Heihe River Basin, Northwest China, from December 2011 to May 2012. Both Neutron Moisture Meter and Time Domain Reflectometry techniques were used to investigate the total soil water content (TSWC) and liquid soil water content (LSWC), respectively, and further based on to calculate soil ice content (SIC) and ice ratio (IR). The partition TSWC into LSWC and SIC at different depths is shown to be corresponded well with soil temperature, frost depth and groundwater dynamics, provided a vigorous basis for augmenting the limited data on soil water redistribution in seasonally frozen soils under natural conditions of different landscapes. The greatest freezing cycles were observed for the farmland, characterized with the deepest frost depths (106 cm), the highest IR (>0.9), and the largest upward heat fluxes (120 W m-2), followed by the forest, and then the desert. These differences were primarily attributed to landscape-dependent initial soil water content, soil surface cover and groundwater levels, with marginal effect being attributed to soil physical properties. Profiled water redistribution upon soil freezing and thawing was obviously observed in the moist forest, but neither in the wettest farmland or in the driest desert. The soil frozen processes had a beneficial effect on soil water conservation with reduced evaporation and seepage, and high water content maintained, which could be useful for plant germination in the following spring.

  3. The characteristics of gravity and magnetic fields and the distribution of tight sandstone gas in the eastern Ordos Basin, China

    Science.gov (United States)

    Yuan, Bingqiang; Zhang, Huaan; Zhang, Chunguan; Xu, Haihong; Yan, Yunkui

    2016-04-01

    In order to perform gas exploration and determine the distribution pattern of gas in the Yanchang Oil Field in the eastern part of the North Shaanxi Slope, Ordos Basin, China, gravity and magnetic survey data were systemically collated, processed and interpreted in combination with the drilling data and recent seismic data. The genesis of gravity and magnetic anomalies and the relationship between the characteristics of the gravity and magnetic fields and known gas distribution were explored in order to predict the favourable exploration targets for gas. Gravity anomalies resulted both from the lateral variation in density of the basement rock and lateral lithologic transformation in the sedimentary cover. The regional magnetic anomalies were mainly caused by the basement metamorphic rocks and the residual magnetic anomalies may reflect the amount and general location of the volcanic materials in the overlying strata. The residual gravity and magnetic anomalies generated by high-density sandstone and high content of volcanics in the gas reservoir of the upper Paleozoic distorted and deformed the anomaly curves when they were stacked onto the primary background anomaly. The gas wells were generally found to be located in the anomaly gradient zones, or the distorted part of contour lines, and the flanks of high and low anomalies, or the transitional zones between anomaly highs and lows. The characteristics of gravity and magnetic fields provide significant information that can be used for guidance when exploring the distribution of gas. Based on these characteristics, five favourable areas for gas exploration were identified; these are quasi-equally spaced like a strip extending from the southeast to the northwest.

  4. Assessing temporal and spatial alterations of flow regimes in the regulated Huai River Basin, China

    Science.gov (United States)

    Zhang, Yongyong; Zhai, Xiaoyan; Shao, Quanxi; Yan, Ziqi

    2015-10-01

    The assessment of flow regime alterations is fundamental in understanding the potential impact of reservoirs and other water infrastructures on aquatic ecosystems and biota. Previously used methods to classify flow regimes have not captured temporal changes between unregulated and regulated flow regimes at individual stations. In this study, a combination of hierarchical classification and trend analysis was used to assess spatial and temporal flow regime alterations in the Huai River Basin, China. Two categories of flow regime indices were selected to characterize the impacts of reservoir and sluice regulation, including the basic flow indices for mean variation, and the cumulative variation indices for long-term alteration. The overall impact of reservoirs and sluices on flow regime included the decrease of high flow magnitudes but the increase of low flow magnitudes through time. Moreover, on average, the flow variability, and the high and low flow frequencies were reduced, while their durations were increased. Reservoirs had a greater impact on flow regimes than sluices. The flow regimes at 18 of 30 stations were altered significantly from a pre-regulation condition and were divided into three main types of alteration corresponding to operational rules of reservoirs and sluices. From a management perspective, water projects in China should address the environmental flow requirements of the rivers, particularly in terms of the hydrologic indices affected mostly by reservoirs and sluices. This study will promote the application of flow regime classification and river restoration in highly regulated basins in China.

  5. 关于西北地区的自然灾害链%Analysis of Natural Disaster Chain in Northwest China

    Institute of Scientific and Technical Information of China (English)

    贾慧聪; 王静爱; 杨洋; 潘东华; 杨佩国; 张万昌

    2016-01-01

    Based on the disaster system theory,according to Chinese Provincial Newspapers Disaster Database (1949-2005),major disaster chains in Northwest China are built:drought disaster chain (divided into high tem-perature-drought chain,drought-pests-disease disaster chain,and drought-wind-sandstorm chain),earthquake dis-aster chain and cold-snow disaster chain.The results show that:less precipitation,high latitude,widespread des-ert,mountains and basins,plateaus and plains and other factors may lead to drought disaster chains.The disaster situation amplified with the processing of disaster chains,increased by the vulnerability of hazard-affected bodies. It is suggested that water resource protection be strengthened in the upstream mountainous arid areas,desertification and desertification be combated in the semi-arid steppe regions,and soil erosion be prevented and controlled in the Yellow River Basin.Taking the earthquake disaster and cold-snow disaster chain as the analysis cases,the corre-sponding mitigation measures are proposed to provide a scientific basis for disaster mitigation for governments.%基于灾害系统理论,根据中国省级报刊灾害数据库(1949-2005年),构建了我国西北地区主要的灾害链:干旱灾害链(分为高温-干旱灾害链、旱灾-虫灾-病害灾害链、旱灾-大风-沙尘暴灾害链)、地震灾害链和寒潮-雪灾灾害链的成灾模式。分析表明:降水少、纬度高、沙漠戈壁广布、山脉与盆地、高原与平川相间等是旱灾灾害链发生、发展的主要原因,灾情随灾害链过程放大,受承灾体脆弱性累积加重。提出干旱内陆区的上游山区加强水源保护,半干旱草原区防治荒漠化、沙化,黄河流域中上游区防治水土流失等区域模式。同时以案例形式分析了地震灾害链和寒潮-雪灾灾害链的致灾、成灾模式,提出了相应的减灾对策,为减灾提供科学依据。

  6. A preliminary biogeochemistry-based quantification of primary productivity of end-Permian deep-water basin in Dongpan Section ,Guangxi ,South China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yang; HE Weihong; FENG Qinglai

    2007-01-01

    In this Paper,the mean primary productivity of the Talung Formation in the deep-water basin(50-500 m depth)of Dongpan,Guangxi,South China,was calculated,of the content of the trace element Cu.Results showed that the primary productivity obtained was comparable with the previously-reported data for the black shale of the Phosphoria Formation,a Permian phosphate deposit in the northwest United States,and also similar to that of the modern deposit in the Cariaco basin,Venezuela.It was observed that the primary productivity increased with the enhanced abundance of algae and photosynthetic bacteria,and with the decrease in both the radiolarian individuals and the body size of brachiopods during the faunal mass extinction.This ecological coupling indicates that the changes of primary productivity are closely related to the propagation and the decline of producers(algae and bacteria),and that consumers(radiolarians and brachiopods)probably have little influence on the changes of primary productivity.

  7. Water geochemistry of the Xijiang basin rivers, South China: Chemical weathering and CO2 consumption

    International Nuclear Information System (INIS)

    Research highlights: → The Xijiang River is the second largest river in China and flows through a large carbonate rock region in South China. → Sulfuric acid, which emanate from acid precipitation and the oxidation of sulfide minerals, is involved as a proton donor in weathering reactions in the Xijiang basin. → Calculated results show that the contribution of cations from rock weathering induced by sulfuric acid accounts for approximately 11.2%. → The flux of CO2 released into the atmosphere is approximately 0.41 x 1012 gC yr-1 produced by sulfuric acid-induced carbonate weathering in the Xijiang basin. → Sulfuric acid-induced carbonate weathering could counterbalance a significant part of the CO2 consumed by silicate weathering. - Abstract: The Xijiang River, the mainstream of the Zhujiang (Pearl) River, which is the second largest river in China in terms of discharge, flows through a large carbonate rock region in South China. The chemical and Sr isotopic compositions of the Xijiang waters were determined during the high-flow season in order to understand the chemical weathering processes, associated CO2 consumption and anthropogenic influences within the carbonate-dominated basin. The major ion compositions of the river waters are characterized by the dominance of Ca2+, Mg2+, HCO3- and are significantly rich in SO42-. The SO42- is mainly derived from the oxidation of sulfide minerals and acid precipitation caused by coal combustion. Chemical and Sr isotopic compositions of the river waters indicate that four reservoirs (carbonates, silicates, evaporites and anthropogenic inputs) contribute to the total dissolved loads. The chemical weathering rates of carbonates and silicates for the Xijiang basin are estimated to be approximately 78.5 and 7.45 ton km-2 a-1, respectively. The total chemical weathering rate of rocks for the Xijiang basin is approximately 86.1 ton km-2 a-1 or 42 mm ka-1, which is much higher than global mean values. The budgets of CO2

  8. Effects of Ultra-drying on Viability and Physiological Characteristics of Platycladus orientalis Seed from Arid and Semiarid Areas of Northwest China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to supply quality seed for vegetation restoration in arid and semiarid areas of Northwest China, the effects of Platycladus orientalis seed storage under ultra-drying and accelerated aging were studied. The seeds were dried from 6.8% to 5.1%, 4.4%, 3.7% and 2.2% MC, respectively, in a desiccator with the silica gel. The germination energy, germination percentage, germination index and vigor index of the seed were investigated. After ultra-drying, groups of seeds were carried on the accelerated agin...

  9. Modeling Ecohydrological Processes and Spatial Patterns in the Upper Heihe Basin in China

    Directory of Open Access Journals (Sweden)

    Bing Gao

    2015-12-01

    Full Text Available The Heihe River is the second largest inland basin in China; runoff in the upper reach greatly affects the socio-economic development in the downstream area. The relationship between spatial vegetation patterns and catchment hydrological processes in the upper Heihe basin has remained unclear to date. In this study, a distributed ecohydrological model is developed to simulate the hydrological processes with vegetation dynamics in the upper Heihe basin. The model is validated by hydrological observations at three locations and soil moisture observations at a watershed scale. Based on the simulated results, the basin water balance characteristics and their relationship with the vegetation patterns are analyzed. The mean annual precipitation and runoff increase with the elevation in a similar pattern. Spatial patterns of the actual evapotranspiration is mainly controlled by the precipitation and air temperature. At the same time, vegetation distribution enhances the spatial variability of the actual evapotranspiration. The highest actual evapotranspiration is around elevations of 3000–3600 m, where shrub and alpine meadow are the two dominant vegetation types. The results show the mutual interaction between vegetation dynamics and hydrological processes. Alpine sparse vegetation and alpine meadow dominate the high-altitude regions, which contribute most to the river runoff, and forests and shrub contribute relatively small amounts of water yield.

  10. The down-faulted basin zone and high disaster risk zone in Shanxi Province, China

    Institute of Scientific and Technical Information of China (English)

    刘惠敏; 苏桂武; 邓砚; 高庆华

    2004-01-01

    Shanxi Province is a region with frequent occurrence of earthquakes, floods and waterlogging, meteorological and geologic hazards, and agrobiohazards in China. The study shows that the formation and development of the down-faulted basin zone in Shanxi Province provides an available condition for preparation and occurrence of these hazards, so that the basin zone becomes an area with frequent occurrence of the hazards, such as earthquakes, floods and waterlogging, meteorological and geologic hazards and agrobiohazards in Shanxi and with their most serious interaction and mutual intensification. Moreover, the basin zone is an area with dense population and most concentrated industrial and agricultural productions and social-economic property in Shanxi. The comprehensive effect of the two factors caused the zone to be a high natural disaster risk area in Shanxi. For reduction of natural disasters and ensuring the sustainable social-economic development in Shanxi, it is necessary to regard the basin zone as an important area for disaster reduction in Shanxi and to carry out integrated disaster reduction.

  11. Spatiotemporal variations of temperature and precipitation extremes in the Poyang Lake basin, China

    Science.gov (United States)

    Zhang, Qiang; Xiao, Mingzhong; Singh, Vijay P.; Wang, Yeqiao

    2016-05-01

    Daily temperature and precipitation data from 15 rain gauges covering a period of 1957-2011 were analyzed using the Mann-Kendall trend test with the aim to investigate changing characteristics of weather extremes in the Poyang Lake basin, the largest freshwater lake in China. Also, the connection between El Niño Southern Oscillation (ENSO) and precipitation extremes is analyzed and possible causes for the connection are briefly discussed. Results indicate that (1) warming, characterized by a decreasing trend in frost days and a significant decrease of temperature extremes defined by lower temperature, in the Poyang Lake basin is observed. Temperature extremes, defined by higher temperature indices such as hot days, exhibit moderate changes with no significant trends. Moreover, warming occurs mainly in the northern part of the Poyang Lake basin; (2) precipitation changes are intensifying as reflected by increasing precipitation extremes. However, these changes are different from 1 month to another and the intensification is found mainly in winter and/or summer months; (3) the influence of ENSO on precipitation changes in the Poyang Lake basin is evident with a time lag of longer than 3 months. This should be due to the fact that higher sea surface temperature tends to trigger the occurrence of convective precipitation regimes. Results of this study are important for modeling the occurrence of precipitation extremes in a changing climate and regional climatic responses to global climate changes.

  12. DRY/WET CLIMATE CHANGE SINCE 960 A. D.IN TAIHU DRAINAGE BASIN OF CHINA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The present study reconstructs an annual dry/wet grade series from 960 A. D. to 1992 A. D. in the Taihu drainage basin of eastern coast, China by collecting historical climatic records, to examine the climate periodicity and climate jumps. Power Spectrum analysis reveals that the dry/wet climate in the study area was a superposed phenomenon with the major period of quasi-100-year, and several other notable periods. These periods were supposed to be closely linked with the celestial activity. Climate junps are detected using moving t-test. The two abrupt changes around 1247 - 1263 A. D. and 1618 - 1635 A. D. are proved as regional events. The 14th to 15th century appeared as the wettest period during the last 1000 years in the Taihu drainage basin. These are interpreted as the consequence of east Asia climate change.

  13. Eddy-entrained Pearl River plume into the oligotrophic basin of the South China Sea

    Science.gov (United States)

    He, Xianqiang; Xu, Dongfeng; Bai, Yan; Pan, Delu; Chen, Chen-Tung Arthur; Chen, Xiaoyan; Gong, Fang

    2016-08-01

    The South China Sea (SCS) is the world's largest tropical marginal sea with an oligotrophic basin. In June 2015, a rare large phytoplankton bloom, which is ~500 km long, 100 km wide and lasting more than 19 days, was captured in the northern SCS basin by satellite daily chlorophyll images. Water within the bloom area had a feature of low salinity and high temperature measured by an accidental-passing cruise. Meanwhile, satellite sea level anomaly images and drifter trajectory proved there was a cyclonic eddy nearby. No typhoon and heavy rain happened in this period, so we believed the bloom was triggered by the injection of nutrient-rich Pearl River plume driven by eddy. This is the first report on eddy-entrained Pearl River plume into the SCS, which would raise a new view on irregular transportation of nutrient and carbon and its related biogeochemical influence on the oligotrophic ocean.

  14. Pricing or Quota? A Solution to Water Scarcity in Oasis Regions in China: A Case Study in the Heihe River Basin

    Directory of Open Access Journals (Sweden)

    Minjun Shi

    2014-10-01

    Full Text Available The conflict between increasing water demand and limited water resources has become a serious threat to oasis regions in China. Solutions to water scarcity have to curb overall water demands, especially reducing agricultural water use. Price control and quantitative control are the two most commonly applied policy instruments for water demand management. This paper used a bio-economic model (BEM to examine the shadow price of water resources and to investigate farmers’ response to water demand management policies in water scarce regions based on a study in the Heihe River Basin in northwest China. The results indicate that farmers are not very responsive to changes in water price, because it is currently far below the shadow price of water resources in most irrigation zones. A reduction of agricultural water demand could occur only with a large rise in the water price. In comparison, a quantitative control measure is more effective at reducing water use. Concerning the effects on farm income, a price control will cost much more than a quantitative control to save the same volume of water. Hence, a water quota is a more suitable choice for the purpose of reducing agricultural water use, while minimizing farm income loss in the region of this case study.

  15. Iodine mobilization in groundwater system at Datong basin, China: Evidence from hydrochemistry and fluorescence characteristics

    International Nuclear Information System (INIS)

    Characterizing the speciation of iodine in groundwater is essential for understanding its hydrogeochemical behavior in aquifer systems. To quantify the variations in iodine speciation and assess factors controlling the distribution and transformation of iodine, 82 groundwater samples and 1 rain water were collected from the Datong basin, northern China in this study. Factor analysis (FA) and excitation emission matrix with parallel factor analysis (EEM–PARAFAC) were used to clarify the potential relationships among iodine species and other hydrochemical parameters. The iodine concentrations of groundwater range from 6.23 to 1380 μg L−1 with 47% of samples exceeding its drinking water level of 150 μg L−1 as recommended by the Chinese government. 57% of samples have ratios of iodate to total iodine greater than 60%, while iodide as the major species in 22% of the samples. Significant amounts of organic iodine with concentrations higher than 100 μg L−1 were observed in 9 groundwater samples. Redox conditions of groundwater system strongly affect iodine concentration and speciation of inorganic iodine in groundwater, and extremely reducing condition restricts the iodine release from sediments into groundwater. The results of FA show that iodine mobilization in groundwater is related to the nature of dissolved organic matter. EEM-PARAFAC model demonstrates the dominance of terrestrial DOM sources and the presence of microbial activities in groundwater system of the Datong basin. It is proposed that degradation of organic matter and reductive dissolution of iron oxyhydroxides are major hydrogeochemical processes responsible for the mobilization of iodine release and the genesis of organic iodine. - Highlights: • Iodine species in groundwater was studied from Datong basin, northern China. • Weakly alkaline environment favors the accumulation of iodine in groundwater. • Iodate is the major species of iodine in groundwater from Datong basin. • Redox

  16. A large Middle Pleistocene freshwater to oligohaline lake in the contemporary hyperarid Qaidam Basin (China)

    Institute of Scientific and Technical Information of China (English)

    Steffen Mischke; Ulrike Herzschuh; Naida Sun; Zizhen Qiao; Zhencheng Sun

    2006-01-01

    @@ The Qaidam Basin (NW China) at the northern margin of the Tibetan Plateau is one of the driest places on Earth with mean annual precipitation not exceeding 25mm in the western central part. Flat salt plains and wind-shaped hills characterise the bare ground over thousands of square kilometres. In contrast to presentday conditions, remnants of ancient shorelines in high positions identified by Chen and Bowler (1986) and Hovermann and Süssenberger (1986) about 20 years ago herald of a former large lake but were not investigated further till now.

  17. New progresses on geothermal history of Turpan-Hami Basin, Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A comprehensive study on geothermal history of the Turpan-HamiBasin by vitrinite reflectance, fluid inclusion geothermometry, apatite fission track and 40Ar-39Ar dating displays that the main effects influencing geotemperature distribution are burial depth of the basement, heat flow, magmatic activities, as well as tectonic movement, having a rugulation to be higher in the east and north, lower in the west and south, as well as higher in the past and lower at the present. The heat of the mantle source and the Indo-China tectonic thermal event have extremely influenced matura-tion of source rocks of the upper Lower Permian and the Middle and Upper Triassic in the lndo-China epoch. While, the geothermal gradient and the weak tectonic geothermal event of the Early Yanshan Movement provided necessary heat for the maturation of source rock in coal-bearing strata of the Middle and Lower Jurassic.

  18. 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

  19. Estimation of tree transpiration and response of tree conductance to meteorological variables in desert-oasis system of Northwest China

    Institute of Scientific and Technical Information of China (English)

    CHEN; Rensheng; KANG; Ersi; ZHANG; Zhihui; ZHAO; Wenzhi; S

    2004-01-01

    in later spring to early summer, and low in summer, and then reaches its largest value in later September. In the mid-November, the sapflow is relatively large, especially the deciduous tree species. This may be characteristic of the tree species in Arid Regions of Northwest China.

  20. Water isotope variations in the snow pack and summer precipitation at July 1 Glacier, Qilian Mountains in northwest China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents the stable isotope data of the snow pack and summer precipitation collected at the July 1 Glacier, Qilian Mountains in northwest China and analyses their relationships with meteorological factors. On an event scale, there is no temperature effect on the δ18O values in the summer precipitation, whereas the amount effect is shown to be clear. By tracing the moisture transport history and comparing the precipitation with its isotopic composition, it is shown that this amount effect not only reflects the change in moisture trajectory, which is related to the monsoon activities, but is also associated with the cooling degree of vapor in the cloud, the evaporation of falling raindrops and the isotopic exchange between the falling drops and the atmospheric vapor. As very little precipitation occurs in winter, the snow pack profile mainly represents the precipitation in the other three seasons. There are low precipitation δ18O ratios in summer and high ratios in spring and autumn. The Meteoric Water Line (MLW) for the summer precipitation is δD = 7.6 δ18O + 13.3, which is similar to that at Delingha, located in the south rim of the Qilian Mountains. The MWL for the snow pack is δD = 10.4 δ18O + 41.4, showing a large slope and intercept. The deuterium excess (d) of the snow pack is positively correlated with δ18O, indicating that both d and δ18O decrease from spring to summer and increase from early autumn to early spring. This then results in the high slope and intercept of the MWL. Seasonal fluctuations of d in the snow pack indicate the change of moisture source and trajectory. During spring and autumn, the moisture originates from continental recycling or rapid evaporation over relatively warm water bodies like Black, Caspian and Aral Seas when the dry westerly air masses pass over them, hence very high d values in precipitation are formed. During summer, the monsoon is responsible for the low d values. This indicates that the monsoon can

  1. 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

  2. Changes in Organic Carbon Index of Grey Desert Soil in Northwest China After Long-Term Fertilization

    Institute of Scientific and Technical Information of China (English)

    XU Yong-mei; LIU Hua; WANG Xi-he; XU Ming-gang; ZHANG Wen-ju; JIANG Gui-ying

    2014-01-01

    Soil organic carbon (SOC), soil microbial biomass carbon (SMBC) and SMBC quotient (SMBC/SOC, qSMBC) are key indexes of soil biological fertility because of the relationship to soil nutrition supply capacity. Yet it remains unknown how these three indexes change, which limits our understanding about how soil respond to different fertilization practices. Based on a 22-yr (1990-2011) long-term fertilization experiment in northwest China, we investigated the dynamics of SMBC and qSMBC during the growing period of winter wheat, the relationships between the SMBC, qSMBC, soil organic carbon (SOC) concentrations, the carbon input and grain yield of wheat as well. Fertilization treatments were 1) nonfertilization (control);2) chemical nitrogen plus phosphate plus potassium (NPK);3) NPK plus animal manure (NPKM);4) double NPKM (hNPKM) and 5) NPK plus straw (NPKS). Results showed that the SMBC and qSMBC were signiifcantly different among returning, jointing, lfowering and harvest stages of wheat under long-term fertilization. And the largest values were observed in the lfowering stage. Values for SMBC and qSMBC ranged from 37.5 to 106.0 mg kg-1 and 0.41 to 0.61%, respectively. The mean value rank of SMBC during the whole growing period of wheat was hNPKM>NPKM>NPKS>CK>NPK. But there were no statistically signiifcant differences between hNPKM and NPKM, or between CK and NPK. The order for qSMBC was NPKS>NPKM>CK>hNPKM>NPK. These results indicated that NPKS signiifcantly increased the ratio of SMBC to SOC, i.e., qSMBC, compared with NPK fertilizer or other two NPKM fertilizations. Signiifcant linear relationships were observed between the annual carbon input and SOC (P<0.01) or SMBC (P<0.05), and between the relative grain yield of wheat and the SOC content as well (P<0.05). But the qSMBC was not correlated with the annual carbon input. It is thus obvious that the combination of manure, straw with mineral fertilizer may be beneift to increase SOC and improve soil quality than

  3. Non-methane hydrocarbons (NMHCs) and their contribution to ozone formation potential in a petrochemical industrialized city, Northwest China

    Science.gov (United States)

    Jia, Chenhui; Mao, Xiaoxuan; Huang, Tao; Liang, Xiaoxue; Wang, Yanan; Shen, Yanjie; Jiang, Wanyanhan; Wang, Huiqin; Bai, Zhilin; Ma, Minquan; Yu, Zhousuo; Ma, Jianmin; Gao, Hong

    2016-03-01

    Hourly air concentrations of fifty-three non-methane hydrocarbons (NMHCs) were measured at downtown and suburb of Lanzhou, a petrochemical industrialized city, Northwest China in 2013. The measured data were used to investigate the seasonal characteristics of NMHCs air pollution and their contributions to the ozone formation in Lanzhou. Annually averaged NMHCs concentration was 38.29 ppbv in downtown Lanzhou. Among 53 NMHCs, alkanes, alkenes, and aromatics accounted for 57%, 23% and 20% of the total NMHCs air concentration, respectively. The atmospheric levels of toluene and propane with mean values of 4.62 and 4.56 ppbv were higher than other NMHCs, respectively. The ambient levels of NMHCs in downtown Lanzhou were compared with measured NMHCs data collected at a suburban site of Lanzhou, located near a large-scale petrochemical industry. Results show that the levels of alkanes, alkenes, and aromatics in downtown Lanzhou were lower by factors of 3-11 than that in west suburb of the city. O3-isopleth plots show that ozone was formed in VOCs control area in downtown Lanzhou and NOx control area at the west suburban site during the summertime. Propylene-equivalent (Prop-Equiv) concentration and the maximum incremental reactivity (MIR) in downtown Lanzhou indicate that cis-2-butene, propylene, and m/p-xylene were the first three compounds contributing to ozone formation potentials whereas in the petrochemical industrialized west suburb, ethane, propene, and trans-2-Butene played more important role in the summertime ozone formation. Principal component analysis (PCA) and multiple linear regression (MLR) were further applied to identify the dominant emission sources and examine their fractions in total NMHCs. Results suggest that vehicle emission, solvent usage, and industrial activities were major sources of NMHCs in the city, accounting for 58.34%, 22.19%, and 19.47% of the total monitored NMHCs in downtown Lanzhou, respectively. In the west suburb of the city

  4. Comparative Study of Basins within Palaeogene Seaway in East China and Cretaceous Seaway in North America and Its Reservoir Significance

    Institute of Scientific and Technical Information of China (English)

    Wu Xiantao

    2007-01-01

    The well known Cretaceous seaway in North America was recognized in the middle of the last century and the Palaeogene seaway in East China was proposed by the author recently. The two seaways located on the opposite sides of North Pacific Ocean may be not a coincidence,and a comparative study was made in this paper. The results show that the two seaways inundated basins share several similarities particularly in basin origin,filling processes and reservoir facies. It is suggested that reservoir facies of estuarine sandstone and shelf bar sandstone related to sea level fluctuation,which are well developed in the Cretaceous seaway covered basins in North America might have been also developed here in Palaeogene seaway inundated basins in East China. Therefore it is worth paying more attention to finding these new reservoir facies on this side of the Pacific ocean. Evidences of sedimentology and ichnology indicate that good prospects are likely.

  5. Accumulation, transfer, and potential sources of mercury in the soil-wheat system under field conditions over the Loess Plateau, northwest China.

    Science.gov (United States)

    Wang, Shengli; Nan, Zhongren; Prete, Daniel; Ma, Jianmin; Liao, Qin; Zhang, Qian

    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 (1.0mg·kg(-1)). Likewise, it was also found that Hg in over 50% of wheat grain samples reached or exceeded the maximum permissible food safety levels (0.02mg·kg(-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. PMID:27300562

  6. A Rainfall Model Based on a Geographically Weighted Regression Algorithm for Rainfall Estimations over the Arid Qaidam Basin in China

    OpenAIRE

    Aifeng Lv; Lei Zhou

    2016-01-01

    Accurate rainfall estimations based on ground-based rainfall observations and satellite-based rainfall measurements are essential for hydrological and environmental modeling in the Qaidam Basin of China. We evaluated the accuracy of daily and monthly scale Tropical Rainfall Measuring Mission (TRMM) rainfall products in the Qaidam Basin. A Geographically Weighted Regression (GWR) was used to estimate the spatial distribution of the TRMM product error using altitude and geographical latitude an...

  7. The quantitative reconstruction of the paleoclimate between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China

    OpenAIRE

    Sun, N; X. Q. Li

    2011-01-01

    The quantitative reconstruction of the paleoclimate is the ultimate goal of studying past global change. Here, the Coexistence Approach (CA) was applied to reconstruct climatic factors quantitatively based on the fossil charcoal records between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China. The climate of the Tianshui Basin belonged to the northern subtropical zone from 5200–4300 cal yr BP. The climatic tolerance ranges were selected, and the lower limit value was regarded as the lo...

  8. The quantitative reconstruction of the palaeoclimate between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China

    OpenAIRE

    Sun, N; X. Q. Li

    2012-01-01

    The quantitative reconstruction of the palaeoclimate is a prerequisite for understanding climate processes at time scales of centuries and millennia. Here, the coexistence approach (CA) was applied to reconstruct climatic factors quantitatively based on the fossil charcoal records between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China. The CA analysis showed that the climate of the Tianshui Basin belonged to the northern subtropical zone between 5200 and 4300 cal yr...

  9. Identification of Water Scarcity and Providing Solutions for Adapting to Climate Changes in the Heihe River Basin of China

    OpenAIRE

    Xiangzheng Deng; Chunhong Zhao

    2015-01-01

    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 pos...

  10. Effects of climate change and human activities on runoff in the Nenjiang River Basin, Northeast China

    Directory of Open Access Journals (Sweden)

    L. Q. Dong

    2012-10-01

    Full Text Available The Nenjiang River Basin (NRB is an important grain-production region with abundant wetlands in Northeast China. Climate change and anthropogenic activities have dramatically altered the spatial and temporal distribution of regional stream discharge and water resources, which poses a serious threat to wetland ecosystems and sustainable agriculture. In this study, we analyzed 55-yr (1956–2010 rainfall and runoff patterns in the river basin to quantitatively evaluate the impact of human activities on regional hydrology. The long-term hydrologic series were divided into two periods: period I (1956–1974, during which minimum land use change occurred, and period II (1975–2010, during which land use change intensified. Kendall's rank correlation test, non-parametric Pettitt test and precipitation-runoff double cumulative curve (DCC methods were utilized to identify the trends and thresholds of the annual runoff in the upstream, midstream, and downstream basin areas. Our results showed that the runoff in the NRB has continuously declined in the past 55 yr, and that the effects of climate change and human activities on the runoff reduction varied in the upstream, midstream and downstream area over different time scales. For the entire study period, climate change has been the dominant factor, accounting for 69.6–80.3% of the reduction in the total basin runoff. However, the impact of human activities has been increasing from 19.7% during the 1950s–1970s to 30.4% in the present time. Spatially, the runoff reduction became higher from the upstream to the downstream areas, revealing an increasing threat of water availability to the large wetland ecosystem in the lower river basin. Furthermore, the sustainable development of irrigated agriculture in the NRB will be a threat to the survival of the wetlands.

  11. Metallogenetic features and perspective evaluation of sandstone-type uranium mineralization in Hailaer Basin, NE, China

    International Nuclear Information System (INIS)

    Hailaer basin is located at the Mongolia-Erguna microplate between Siberian and North-China plates. The basement of the basin is composed of Precambrian igneous and metamorphic rocks, which experienced multiple granitization, and Late Paleozoic, Mesozoic granites and acidic-intermediate volcanics constituting a uranium-enriched provenance area. The sedimentary cover of the basin consists of continental sedimentary series of Late Jurassic to Tertiary. Of them, Lower Cretaceous (Damouguaihe Formation) clastics of alluvial, fan-delta and fluvial facies rich in organic matter are the main uranium ore-hosting series. Numerous uranium occurrences have been found at the western part of the basin, and uranium mineralization mainly occurs in coarse-grained clastics of the second and third members of Damouguaihe Formation. Uranium ore bodies usually are tabular, a few roll-shaped. The thickness of individual orebody ranges from 0.3m to 5m. Ore grade commonly is 0.0n% with the encountered highest grade of 0.38%. Uranium in ores is in adsorption form, heterogeneously disseminated in the cement of sandstone. No independent uranium mineral has been found. Associated elements in ores include Mo, V, Se, Sc, and Re. Discovered uranium mineralization in the basin approximately occurs at the same elevation intervals (660-680m), suggesting the paleo-phreatic origin. Uranium mineralization is mostly localized in permeable sandstone units of fluvial and fan-delta facies with high content of organic matter. Ore-formation age is supposed to be the period from K2 to N when the ore-hosting sedimentary series outcropped at the surface and was eroded. High content of uranium in provenance area, existence of permeable ore-hosting sandstone units and the oxidation (phreatic and interlayer) alteration of ore-hosting sandstone after its deposition under arid climate environments are key factors determining the perspective potential of uranium ore-formation. (author)

  12. Meso-Cenozoic Tectono-Thermal Evolution History in Bohai Bay Basin, North China

    Institute of Scientific and Technical Information of China (English)

    Yinhui Zuo; Nansheng Qiu; Jiawei Li; Qingqing Hao; Xiongqi Pang; Zhongying Zhao; Qi Zhu

    2015-01-01

    The thermal history of sedimentary basins is a key factor for hydrocarbon accumula-tion and resource assessment, and is critical in the exploration of lithospheric tectono-thermal evo-lution. In this paper, the Cenozoic thermal histories of nearly 200 wells and the Mesozoic thermal histories of 15 wells are modeled based on the vitrinite reflectance and apatite fission track data in Bohai Bay Basin, North China. The results show that the basin experienced Early Cretaceous and Paleogene heat flow peaks, which reveals two strong rift tectonic movements that occurred in the Cretaceous and the Paleogene in the basin, respectively. The thermal evolution history in Bohai Bay Basin can be divided into five stages including (1) the low and stable heat flow stage from the Trias-sic to the Jurassic, with the heat flow of 53 to 58 mW/m2;(2) the first heat flow peak from the Early Cretaceous to the middle of the Late Cretaceous, with a maximum heat flow of 81 to 87 mW/m2;(3) the first post-rift thermal subsidence stage from the middle of the Late Cretaceous to the Paleocene, with the heat flow of 65 to 74 mW/m2 at the end of the Cretaceous; (4) the second heat flow peak from the Eocene to the Oligocene, with a maximum heat flow of 81 to 88 mW/m2;and (5) the second thermal subsidence stage from the Neogene to present, with an average heat flow of 64 mW/m2.

  13. Integrated Analysis on Gravity and Magnetic Fields of the Hailar Basin, NE China: Implications for Basement Structure and Deep Tectonics

    Science.gov (United States)

    Sun, B.; Wang, L.; Dong, P.; Scientific Team Of Applied Geophysics

    2010-12-01

    The Hailar Basin is one of the most representative basins among the Northeast China Basin Group, which is situated in the east of East Asia Orogene between the Siberia Plate and the North China Plate. Based on the detailed analysis of the Bouguer gravity anomaly, aeromagnetic anomaly as well as petrophysical data, we studied the features of gravity-magnetic fields in the basin and its neighboring areas. A combined approach of Wavelet Multi-scale Decomposition and Power Spectrum Analysis was adopted to quantitatively grade the gravity and magnetic anomalies into four levels. Accordingly, the apparent depths of the source fields can be assessed. The results reveal the crustal density and magnetic structures of the Hailar Basin. Low-order wavelet details of gravity-magnetic anomalies were carried out on studying basin basement structure. Seven major basement faults of the basin were identified, and the basement lithology was discussed and predicted. Three major uplifts and 14 depressions were delineated according to basement depth inversion by the Park method. High-order wavelet approximations of gravity-magnetic anomalies were carried out on studying deep tectonics of the basin. The average Moho depth of the study area is about 40 km, with a mantle uplift located in the northeast of the basin. The average depth of the Curie interface is about 19 km, while the uplift of the Curie interface is in the basin center and its east and west sides are depressions. Finally, inversion of Bouguer gravity anomalies was conducted on an across-basin GGT profile using the Wavelet Multi-scale Decomposition. The inversion results are consistent with those of GGT seismic inversion, suggesting that the Wavelet Multi-scale Decomposition can be applied to distinguish major crustal density interfaces.

  14. Application of valve-regulated lead-acid batteries for storage of solar electricity in stand-alone photovoltaic systems in the northwest areas of China

    Science.gov (United States)

    Hua, Shounan; Zhou, Qingshen; Kong, Delong; Ma, Jianping

    Photovoltaic (PV) installations for solar electric power generation are being established rapidly in the northwest areas of China, and it is increasingly important for these power systems to have reliable and cost effective energy storage. The lead-acid battery is the more commonly used storage technology for PV systems due to its low cost and its wide availability. However, analysis shows that it is the weakest component of PV power systems. Because the batteries can be over discharged, or operated under partial state of charge (PSOC), their service life in PV systems is shorter than could be expected. The working conditions of batteries in remote area installations are worse than those in situations where technical support is readily available. Capacity-loss in lead-acid batteries operated in remote locations often occurs through sulfation of electrodes and stratification of electrolyte. In northwest China, Shandong Sacred Sun Power Sources Industry Co. Ltd. type GFMU valve-regulated lead-acid (VRLA) batteries are being used in PV power stations. These batteries have an advanced grid structure, superior leady paste, and are manufactured using improved plate formation methods. Their characteristics, and their performance in PV systems, are discussed in this paper. The testing results of GFMU VRLA batteries in the laboratory have shown that the batteries could satisfy the demands of the International Electrotechnical Commission (IEC) standards for PV systems.

  15. Application of valve-regulated lead-acid batteries for storage of solar electricity in stand-alone photovoltaic systems in the northwest areas of China

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Shounan; Zhou, Qingshen; Kong, Delong; Ma, Jianping [Shandong Sacred Sun Power Sources Industry Co. Ltd., Qufu 273100 (China)

    2006-08-25

    Photovoltaic (PV) installations for solar electric power generation are being established rapidly in the northwest areas of China, and it is increasingly important for these power systems to have reliable and cost effective energy storage. The lead-acid battery is the more commonly used storage technology for PV systems due to its low cost and its wide availability. However, analysis shows that it is the weakest component of PV power systems. Because the batteries can be over discharged, or operated under partial state of charge (PSOC), their service life in PV systems is shorter than could be expected. The working conditions of batteries in remote area installations are worse than those in situations where technical support is readily available. Capacity-loss in lead-acid batteries operated in remote locations often occurs through sulfation of electrodes and stratification of electrolyte. In northwest China, Shandong Sacred Sun Power Sources Industry Co. Ltd. type GFMU valve-regulated lead-acid (VRLA) batteries are being used in PV power stations. These batteries have an advanced grid structure, superior leady paste, and are manufactured using improved plate formation methods. Their characteristics, and their performance in PV systems, are discussed in this paper. The testing results of GFMU VRLA batteries in the laboratory have shown that the batteries could satisfy the demands of the International Electrotechnical Commission (IEC) standards for PV systems. (author)

  16. Research on the Tourism Competitiveness of Qinghai in Northwest China%青海省在西北地区的旅游竞争力研究

    Institute of Scientific and Technical Information of China (English)

    罗正霞; 李玲琴; 李春花; 卓玛措; 黄芸玛

    2009-01-01

    Using Porter's diamond model, AHP method and SPSS statistical software,a comprehensive evaluation was made on the tourism industry in different provinces of Northwest China, based on analyzing the tourism reality competitiveness, potential competitiveness, supporting competitiveness, regional economic conditions and the overall competitiveness.Meanwhile,the tourism status of Qinghai in Northwest China was deeply analyzed and some appropriate countermeasures for enhancing its tourism competitiveness were put forward.%基于波特钻石模型,采用层次分析法,借助SPSS统计软件对西北各省旅游业现实竞争力、支持竞争力、潜在竞争力、区域经济条件及综合竞争力做出综合评价,深入分析青海省旅游业在西北地区的地位并指出提升青海省旅游竞争力的相应对策.

  17. Association between Changing Mortality of Digestive Tract Cancers and Water Pollution: A Case Study in the Huai River Basin, China

    OpenAIRE

    Hongyan Ren; Xia Wan; Fei Yang; Xiaoming Shi; Jianwei Xu; Dafang Zhuang; Gonghuan Yang

    2014-01-01

    The relationship between the ever-increasing cancer mortality and water pollution is an important public concern in China. This study aimed to explore the association between serious water pollution and increasing digestive cancer mortality in the Huai River Basin (HRB) in China. A series of frequency of serious pollution (FSP) indices including water quality grade (FSPWQG), biochemical oxygen demand (FSPBOD), chemical oxygen demand (FSPCOD), and ammonia nitrogen (FSPAN) were used to characte...

  18. 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.

  19. Progress and outlook of uranium exploration in meso-cenozoic basins in north China

    International Nuclear Information System (INIS)

    Through the efforts in last decades on the research of geology setting and regional assessment for uranium exploration in the Meso-Cenozoic basins in North China, rich accomplishment have been gotten in metallogenic theory, temporal and spatial distribution pattern, zone division, Classification, mineralization of different type, ore-controlling factors, metallogenic model, principle of valuation and prognostication, exploration criteria and great breakthrough in the prospecting of key areas. However, the extensive territory make the effort limited only to some region, the exploration level is fairly lower in the whole country, and there is wide space for uranium exploration. The further exploration should be basically guided by 'highlighting the exploration of key areas, strengthening the evaluation of regional potential and accelerating the implementation of new reserve bases' and persisted in principle of 'deployment with different level and execution according to region' and oriented with different types of deposit by 'wholly evaluation and systematic exploration'. By deploying the new effort frame in large base exploration, regional evaluation and solving the important geological and geophysical problem, we can put forward the uranium exploration in Meso-Cenozoic basins in North China. (author)

  20. 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.

  1. Structural style and Basin Formation in Deep-water Area of Northern South China Sea

    Science.gov (United States)

    di, Z.; Zhen, S.; Xiong, P.; Min, C. C.

    2007-12-01

    In the deep-water area of northern South China Sea (SCS) developed a series of sedimentary basins. Active exploration for deep-water hydrocarbon has begun in these areas since this century. The well LW3-1-1 at water depth of 1480m in the BaiYun Sag (BYS) of the Pearl River Mouth Basin in 2006 discovered 56m layer of pure gas, demonstrated the good hydrocarbon potential of the area. Wide-angle seismic profiling has verified the transitional type of crust in the slope areas. The Moho surface shoals step-by-step from 30-29km under the shelf, ~15 km under the slope, and ~12km under the abyssal plain. Moho also rises beneath depocenters, mirroring the shape of sedimentary basement. The crustal thickness at the center of the BYS is Pacific Ocean towards the East Eurasian margin. The stress field in the East Eurasian margin changed abruptly in Late Cretaceous. Rifting started in the entire margin and eventually led to the opening of the SCS in late Early Oligocene. Large sedimentary basins developed in the margins of the SCS. Paleogene lacustrine sediments contain hydrocarbon sources, while traps are mostly found in Neogene marine strata. The structure of the northern SCS shows clear W-E variation, divided into NE-, NEE-, and NE-trending segments by two major NW-SE transfer faults. The Southern Depression of the Qiongdongnan Basin to the west is characterized by NE-trending half grabens. The BYS at the central segment is characterized by NEE-trending composite grabens and down warps with relatively small offset of boundary faults. To the east the Chaoshan Depression is composed of Mesozoic strata under very thin (deep-water basins is different from that of shallow-water basins. A study is ongoing to explore the basin formation mechanism, taking into account of the factors of abnormal lithosphere rheology, active mantle underplating and magmatic heating, lower crust flow, as well as the superposition of later extensional events. The study is supported by NSFC grants

  2. Groundwater recharge history and hydrogeochemical evolution in the Minqin Basin, North West China

    International Nuclear Information System (INIS)

    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

  3. Institutional Arrangements for River Basin Management: A Case Study of Comparison between the United States and China

    Institute of Scientific and Technical Information of China (English)

    ZHOU Gang-yan

    2007-01-01

    This note compares institutional arrangements for water resources management in two river basins, namely, those of the Susquehanna River in the United States and the Yangtze River in China. The Susquehanna River Basin Commission is composed of the US federal government and the three states of New York, Pennsylvania, and Maryland through which the Susquehanna River passes. Under the authority of the Susquehanna River Basin Compact, the Commission deals with water resources problems throughout its vast drainage area. In contrast, the Changjiang(Yangtze River) Water Resources Commission (CWRC) lacks relative effectiveness in mobilizing provincial governments in transboundary water resources management.

  4. Relationship between Formation of Zhongyebei Basin and Spreading of Southwest Subbasin, South China Sea

    Institute of Scientific and Technical Information of China (English)

    Gao Hongfang; Zhou Di; Qiu Yan

    2009-01-01

    The Zhongyebei (中业北) basin (ZYBB) is an NE-striking,narrow and small sedimentary basin superimposing the southern 1/2 segment of the proposed spreading axes of the SW subbasin of the South China Sea (SCS).More than 4 500 m strata were identified in the Zhongyebei basin,including the Paleogene lower structure layer and the Neogene upper structure layer.The SW subbasin of the South China Sea has been regarded as an oceanic basin opened by seafloor spreading,as evidenced by the fiat and deep (> 4 000 m mostly) seafloor with linear magnetic anomalies,and by the shallow Moho depth of < 12 km as estimated from gravity modeling.The classic model of seafloor spreading predicts that sediments on the oceanic crust are younger and thinner towards the spreading axes.But in the southwestern segment of the SW subbasin,contradictions appear.Firstly,the thick sedimentation in the ZYBB is along the proposed spreading axes.Secondly,the sediments are thinner (500-1 500 m) and younger away from the proposed spreading axes.Thirdly,geological elements of the two sides of spreading axes develop asymmetrically in the southwestern SW subbasin.Two models,the early opening model and the limited modeling model,are suggested for resolving this paradox.The former suggests that the opening of the SW subbasin was in Late Eocene and earlier than the oldest sediment in the ZYBB.The latter proposes that the opening of the SW subbasin was limited to its northeastern portion,and did not extend to the southwest portion.The ZYBB is a rift basin survived from the spreading but subjected to severe syn-spreading magmatic disturbance.The SW subbasin and the ZYBB of the SCS provide a unique opportunity for studying the structural evolution and dynamic mechanism at the tip of a propagating seafloor spreading.Both models have unresolved questions,and further studies are needed.

  5. Nitrogen isotopic geochemical characteristics of crude oils in several basins of China

    Institute of Scientific and Technical Information of China (English)

    CHEN Chuanping; MEI Bowen; CAO Yacheng

    2005-01-01

    Nitrogen isotopic ratios of crude oils with different physical and chemical properties in several basins of China have been measured and their geochemistry has been studied elementally combined with molecular organic geochemistry methods. The data indicate that δ15N is in the range of -6‰-20‰. They vary with the oils in different sedimentary types of basins. The oils forming in the limnic environment have lower δ15N with the value of about 1‰-5‰ whereas the oils in saline or semi-saline environment have higher δ15N, with most samples being above 10‰ and some exceeding 17‰. The average nitrogen isotopic ratio of oils from the Ordovician formation in the Tarim Basin is the lowest, with most samples having δ15N below zero, which reflects possibly the characteristic of the oils originating mainly from the organic matter formed in marine carbonate sedimentary environment. The δ15N distribution can be altered by fractionation. It increases obviously because of biodegradation and decreases during hydrocarbon migration. However, the effect of nitrogen isotopic fractionation in the short distance migration is unconspicuous.

  6. Denitrifying Bacteria in Paddy Soils of Taihu Lake Basin,China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hua-Yong; LI Zhen-Gao; PAN Ying-Hua; LI Liang-Mo

    2004-01-01

    This study attempted to determine the characteristics of the communities, the ecological factors, and the denitrifying enzyme activity for denitrifying bacteria found in the paddy soils of the Taihu Lake Basin, China. Samples of the six main soil types of the basin were taken from paddy fields with different fertilities. The total numbers of bacteria and denitrifying bacteria in the high fertility soils were much more than those in low fertility soils, and the number of denitrifying bacteria accounted for 49% to 80% of the total number of bacteria. The O2 content was an important ecological factor that affected denitrification. Of test the strains isolated from the paddy soils in the Taihu Lake Basin, some (e.g., Pseudomonas spp.)grew well under low oxygen partial pressure, while others (e.g., Bacillus spp.) had no strict predilection with O2 content.Another critical ecological factor was the nitrogen concentration. Three selected denitrifying bacteria grew better in a culture medium with 135 instead of 276 mg L-1 nitrogen. At the same time 67% of the test strains were able to reduce NO-3 to NO-2 and 56% had N2O reductase.

  7. Multifractal analyses of daily rainfall time series in Pearl River basin of China

    CERN Document Server

    Yu, Zu-Guo; Chen, Yongqin David; Zhang, Qiang; Anh, Vo; Zhou, Yu

    2014-01-01

    The multifractal properties of daily rainfall time series at the stations in Pearl River basin of China over periods of up to 45 years are examined using the universal multifractal approach based on the multiplicative cascade model and the multifractal detrended fluctuation analysis (MF-DFA). The results from these two kinds of multifractal analyses show that the daily rainfall time series in this basin have multifractal behavior in two different time scale ranges. It is found that the empirical multifractal moment function $K(q)$ of the daily rainfall time series can be fitted very well by the universal mulitifractal model (UMM). The estimated values of the conservation parameter $H$ from UMM for these daily rainfall data are close to zero indicating that they correspond to conserved fields. After removing the seasonal trend in the rainfall data, the estimated values of the exponent $h(2)$ from MF-DFA indicate that the daily rainfall time series in Pearl River basin exhibit no long-term correlations. It is a...

  8. Landscape Changes from 1974 to 1995 in the Upper Minjiang River Basin, China

    Institute of Scientific and Technical Information of China (English)

    HE Xing-Yuan; ZHAO Yong-Hua; HU Yuan-Man; CHANG Yu; ZHOU Qi-Xing

    2006-01-01

    Landscape changes were traced over the 20 years from 1974 to 1995 in the upper Minjiang River basin, one of the most important forest regions in China, based on satellite image interpretation to provide basic data for local decision-making as well as sustainable landscape use and management. Results revealed that landscape from 1974 to 1995 changed at the regional scale as the area of forestland decreased, while cropland, shrubland, economic forest, grassland, and built-up land increased. Landscape changes mainly occurred in forestland, shrubland, grassland, economic forest, and built-up land. Moreover, the changes among forestland, shrubland, and grassland were the largest, influencing the whole characteristics of the changes in the basin. Analysis of the changes between 1974 and 1995 in the study area indicated that landscape heterogeneity and fragmentation increased, whereas landscape connectivity decreased. There were multiple reasons for landscape changes. A principal component analysis (PCA) was used to quantitatively study driving forces of landscape changes. The PCA results showed that economic and population factors were the principal driving forces of landscape changes from 1974 to 1995 in the upper Minjiang River basin, and that PCA was a suitable method for investigating driving forces of landscape changes.

  9. An isotope hydrochemical approach to understand fluoride release into groundwaters of the Datong Basin, Northern China.

    Science.gov (United States)

    Su, Chunli; Wang, Yanxin; Xie, Xianjun; Zhu, Yapeng

    2015-04-01

    The hydrogeochemical and isotopic investigations of high fluoride (up to 8.26 mg L(-1)) groundwater in the Datong Basin, Northern China were carried out in order to evaluate the geochemical controls on fluoride enrichment. The groundwater fluoride concentration tends to increase along with the regional groundwater flow path away from the basin margins, towards the central parts of the basin. Groundwater with high F concentrations has a distinctive major ion chemistry, being generally HCO3(-)-rich, Na-rich, Ca-poor, and having weak alkaline pH values (7.2 to 8.2) and Na-HCO3 waters. These data indicate that variations in the groundwater major ion chemistry and possibly pH, which are controlled by water-rock interaction processes in the aquifer, are important in mobilizing F. Positive correlations between fluoride with lithogenic sodium (LNa) and HCO3(-) in groundwater show that the high fluoride content and alkaline sodic characteristics of groundwater result from dissolution of fluorine-bearing minerals. The occurrence and behavior of fluorine in groundwater are mainly controlled by fluorite precipitation as a function of Ca(2+) concentration. A positive correlation between fluoride and δ(18)O, low F(-)/Cl(-) ratios, and the low tritium level in the fluoride-rich groundwater indicate the effects of long-term water-rock interactions and intensive evapotranspiration. PMID:25743227

  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. A continental slope stability evaluation in the Zhujiang River Mouth Basin in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    LIU Ke; WANG Jianhua

    2014-01-01

    In nature, a slope stability is determined by the ratio of a sliding resistance to a slide force. The slide force of a marine deep-water continental slope is mainly affected by sediment mechanics properties, a topography, and a marine seismic. However, the sliding resistance is mainly affected by sedimentary patterns and a sedi-mentary stress history. Both of these are different from case to case, and their impact can be addressed when the data are organized in a geographic information system (GIS). The study area on the continental slope in Zhujiang River Mouth Basin in South China Sea provides an excellent opportunity to apply GIS spatial analysis technology for the evaluation of the slope stability. In this area, a continental slope topography and a three-dimension (3-D) topography mapping show a sea-floor morphology and the distribution of a slope steepness in good detail, and the sediment analysis of seabed samples and an indoor appraisal reveals the variability of a sediment density near the sea-floor surface. On the basis of the results of nine geotechnical studies of submarine study areas, it has worked out that an equivalent cyclic shear stress ratio is roughly between 0.158 and 0.933, which is mainly depending on the initial water content of sediment. A regional density, slope and level of anticipated seismic shaking information are combined in a GIS framework to yield a map that illustrates a continental slope stability zoning under the influencing factors in Zhujiang River Mouth Basin in the South China Sea. The continental slope stability evaluation can contribute to north resources development in the South China Sea, the marine functional zoning, the marine engineering con-struction and adjust measures to local conditions, at the same time also can provide references for other deep-water slope stability analysis.

  12. The depositional setting of the Late Quaternary sedimentary fill in southern Bannu basin, Northwest Himalayan fold and thrust belt, Pakistan.

    Science.gov (United States)

    Farid, Asam; Khalid, Perveiz; Jadoon, Khan Zaib; Jouini, Mohammed Soufiane

    2014-10-01

    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. PMID:25004850

  13. 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.

  14. Application of isotope techniques to groundwater investigation in the Erdos Basin, China

    International Nuclear Information System (INIS)

    Full text: The Erdos Basin is located in the eastern part of Northwestern China and extends over parts of 5 provinces: Shaanxi, Gansu, Ningxia, Inner Mongolia and Shanxi. The basin is surrounded by the Yellow River to the west, north and east and the Weihe River, the largest tributary of the Yellow River, flows through the southern basin from west to east. The Erdos Basin covers an area of about 400 000 km2 and is a plateau depression basin caused by structural uplift. The early Cretaceous sediments which form the artesian basin consist of six primary hydrostratigraphic units with a total thickness of 1000m. Generally, Ordovcian carbonate rock formations form karstic aquifers that flank the east, south and west of the basin distributed in a U-shape forming the peripheral mountains and hills with an area covering about 100 000 km2. The groundwater resources of the basin are strategically important and this ongoing IAEA TC-project (CPR/08/12) was undertaken in 2001-2002, with the major tasks being to evaluate the availability of groundwater resources, especially the recharge process and recharge rate, to understand the inter-relationship between groundwater system and surface water and between different groundwater aquifers, to determine the age of groundwater, and explore the possibility of utilizing deep groundwater. The objective is to improve groundwater investigation and management in arid and semi-arid regions in China through integrating isotope techniques. This paper reports upon work in progress through collection, collation and analysis of climatic, geological, hydrogeological hydrochemical data, water sampling and laboratory analysis, isotope technique training. A double-packer sampling system is being used to collect discreet-level water samples from target hydro-stratigraphic units via uncased boreholes up to 1000m in depth. Four rainfall stations for rain collection have been set up in the Erdos Basin and 50 water samples for D, 18O, T were collected

  15. Flash flood hazard mapping: a pilot case study in Xiapu River Basin, China

    Directory of Open Access Journals (Sweden)

    Da-wei Zhang

    2015-07-01

    Full Text Available Flash flood hazard mapping is a supporting component of non-structural measures for flash flood prevention. Pilot case studies are necessary to develop more practicable methods for the technical support systems of flash flood hazard mapping. In this study, the headwater catchment of the Xiapu River Basin in central China was selected as a pilot study area for flash flood hazard mapping. A conceptual distributed hydrological model was developed for flood calculation based on the framework of the Xinanjiang model, which is widely used in humid and semi-humid regions in China. The developed model employs the geomorphological unit hydrograph method, which is extremely valuable when simulating the overland flow process in ungauged catchments, as compared with the original Xinanjiang model. The model was tested in the pilot study area, and the results agree with the measured data on the whole. After calibration and validation, the model is shown to be a useful tool for flash flood calculation. A practicable method for flash flood hazard mapping using the calculated peak discharge and digital elevation model data was presented, and three levels of flood hazards were classified. The resulting flash flood hazard maps indicate that the method successfully predicts the spatial distribution of flash flood hazards, and it can meet the current requirements in China.

  16. Development of a model-based flood emergency management system in Yujiang River Basin, South China

    Science.gov (United States)

    Zeng, Yong; Cai, Yanpeng; Jia, Peng; Mao, Jiansu

    2014-06-01

    Flooding is the most frequent disaster in China. It affects people's lives and properties, causing considerable economic loss. Flood forecast and operation of reservoirs are important in flood emergency management. Although great progress has been achieved in flood forecast and reservoir operation through using computer, network technology, and geographic information system technology in China, the prediction accuracy of models are not satisfactory due to the unavailability of real-time monitoring data. Also, real-time flood control scenario analysis is not effective in many regions and can seldom provide online decision support function. In this research, a decision support system for real-time flood forecasting in Yujiang River Basin, South China (DSS-YRB) is introduced in this paper. This system is based on hydrological and hydraulic mathematical models. The conceptual framework and detailed components of the proposed DSS-YRB is illustrated, which employs real-time rainfall data conversion, model-driven hydrologic forecasting, model calibration, data assimilation methods, and reservoir operational scenario analysis. Multi-tiered architecture offers great flexibility, portability, reusability, and reliability. The applied case study results show the development and application of a decision support system for real-time flood forecasting and operation is beneficial for flood control.

  17. Chemical composition, sources, and processes of urban aerosols during summertime in Northwest China: insights from High Resolution Aerosol Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    J. Xu

    2014-06-01

    Full Text Available 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

  18. Controls on alkylphenol occurrence and distribution in oils from lacustrine rift basins in East China

    Institute of Scientific and Technical Information of China (English)

    ZHOU ShuQing; HUANG HaiPing

    2008-01-01

    Oils from two lacustrine rift basins in east China are thoroughly investigated using geochemical method to understand controls on alkylphenol occurrence and distribution in oils. Oils in the Lujiapu Depression,Kailu Basin are derived from the Cretaceous source rocks,and those in the Dongying Depression,Bohai Bay Basin,from the Tertiary source rocks. All oils are experienced relatively short distance of migration and have similar maturity in each basin. Differences in homologue distributions from different oilfields are most likely caused by organic facies variation of source rocks. The oils in the Lujiapu Depression are characterized by high proportion of C3 alkylphenols (prefixes refer to the number of alkylcarbons joined to the aromatic ring of the phenol molecule) and low proportion of cresols and C2 alkylphenols compared to oils from the Dongying Depression. Alkylphenol isomer distribution is possibly affected by depositional environment especially for C3 alkylphenols. Dysoxic freshwater environment is favorable for the formation of propyl or isopropyl substituted C3 alkylphenols,while highly reducing saline water is more suitable for trimethyl substituted C3 alkylphenols. Variations in alkylphenol concentrations within a petroleum system are controlled mainly by secondary migration processes with alkylphenol concentrations decreasing along migration direction. Interestingly,coupled with geological factors,a subtle change of alkylphenol concentrations can be applied to differentiate carrier systems. When oil migrates through sandy beds,concentrations of total alkylphenols decrease dramatically with migration distance,while such change is less significant when oil migrates vertically along faults. However,most isomer ratios potentially related to migration distance are not as effective as those alkylcarbazoles in migration diagnosis due to complicated affecting factors.

  19. Unravelling the factors influencing flooding over the last 60 years in the Wei River Basin, China

    Science.gov (United States)

    Gai, Lingtong; Baartman, Jantiene E. M.; Mendoza-Carranza, Manuel; Wang, Fei; Ritsema, Coen J.; Geissen, Violette

    2016-04-01

    Flood hazard has become a growing concern in the Wei River Basin in China due to the extensive damage to private and public property under the pressure of extreme meteorological events and human intervention in the river basin. A better understanding of the influence of topographic, climatic and especially anthropogenic factors on hydrological discharge and flooding are important for flood regime and water resources management. This study is aiming at answering the questions why, where, when, and how flooding occurs. While most studies focus on single flood events, we aimed at unravelling a multitude of factors contributing to flooding over a decadal timespan. To be able to do this, we used conditional inference tree analysis, a promising method not often applied in hydrological studies. This method allows to rank all the influencing factors by its contribution to the occurrence of flooding therefore to identify the most important ones and spatially important subcatchments leading to flooding on both yearly and monthly bases in the basin. Dam construction period was identified as the most important factor (why) affecting flooding, followed by the elevation of the river outlet. The subcatchment farthest upstream in the basin (where) contributed the most to the discharge at the downstream floodplain. We then analyzed the impact of the periods of dam construction on the precipitation-discharge relationship using cross-correlation and double mass curves analysis, respectively. The results showed a smaller effect of dam construction on the time lags (when) between precipitation and discharge than on the effect of reducing the quantity of discharge (how).

  20. A feasibility study of geological CO2 sequestration in the Ordos Basin, China

    Science.gov (United States)

    Jiao, Z.; Surdam, R.C.; Zhou, L.; Stauffer, P.H.; Luo, T.

    2011-01-01

    The Shaanxi Province/Wyoming CCS Partnership (supported by DOE NETL) aims to store commercial quantities of CO2 safely and permanently in the Ordovician Majiagou Formation in the northern Ordos Basin, Shaanxi Province, China. This objective is imperative because at present, six coal-to-liquid facilities in Shaanxi Province are capturing and venting significant quantities of CO2. The Wyoming State Geological Survey and the Shaanxi Provincial Institute of Energy Resource and Chemical Engineering conducted a feasibility study to determine the potential for geological CO2 sequestration in the northern Ordos Basin near Yulin. The Shaanbei Slope of the Ordos Basin is a huge monoclinal structure with a high-priority sequestration reservoir (Majiagou Formation) that lies beneath a 2,000+ meter-thick sequence of Mesozoic rocks containing a multitude of lowpermeability lithologies. The targeted Ordovician Majiagou Formation in the location of interest is more than 700 meters thick. The carbonate reservoir is located at depths where pressures and temperatures are well above the supercritical point of CO2. The targeted reservoir contains high-salinity brines (20,000-50,000 ppm) that have little or no economic value. The targeted reservoir is continuous as inferred from well logs, and cores show that porosity ranges from 1 to 15% with average measured porosity of 8%, and that permeability ranges from 1-35 md. This paper focuses on calculations that will help evaluate the capacity estimates through the use of high-resolution multiphase numerical simulation models, as well as a more simple volumetric approach. The preliminary simulation results show that the Ordovician Majiagou Formation in the Ordos Basin has excellent potential for geological CO2 sequestration and could store the CO2 currently emitted by coal-to-liquid facilities in Shaanxi Province for hundreds of years (i.e., 9 Mt/year CO2; 450 Mt over a 50-year period at one injection site). ?? 2011 Published by Elsevier Ltd.

  1. Magnetostratigraphic dating of the Xiashagou Fauna and implication for sequencing the mammalian faunas in the Nihewan Basin, North China

    NARCIS (Netherlands)

    Liu, Ping; Deng, Chenglong; Li, Shihu; Cai, Shuhui; Cheng, Hongjiang; Wei, Qi; Zhu, Rixiang

    2012-01-01

    The Nihewan Basin sedimentary sequences in northern China are rich in mammalian fossil and Paleolithic sites, thus providing insights into our understanding of Quaternary land mammal biochronology and early human settlements in East Asia. Here we present high-resolution magnetostratigraphic results

  2. 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 bio-e

  3. Revised conceptualization of the North China Basin groundwater flow system: Groundwater age, heat and flow simulations

    Science.gov (United States)

    Cao, Guoliang; Han, Dongmei; Currell, Matthew J.; Zheng, Chunmiao

    2016-09-01

    Groundwater flow in deep sedimentary basins results from complex evolution processes on geological timescales. Groundwater flow systems conceptualized according to topography and/or groundwater table configuration generally assume a near-equilibrium state with the modern landscape. However, the time to reach such a steady state, and more generally the timescales of groundwater flow system evolution are key considerations for large sedimentary basins. This is true in the North China Basin (NCB), which has been studied for many years due to its importance as a groundwater supply. Despite many years of study, there remain contradictions between the generally accepted conceptual model of regional flow, and environmental tracer data. We seek to reconcile these contractions by conducting simulations of groundwater flow, age and heat transport in a three dimensional model, using an alternative conceptual model, based on geological, thermal, isotope and historical data. We infer flow patterns under modern hydraulic conditions using this new model and present the theoretical maximum groundwater ages under such a flow regime. The model results show that in contrast to previously accepted conceptualizations, most groundwater is discharged in the vicinity of the break-in-slope of topography at the boundary between the piedmont and central plain. Groundwater discharge to the ocean is in contrast small, and in general there are low rates of active flow in the eastern parts of the basin below the central and coastal plain. This conceptualization is more compatible with geochemical and geothermal data than the previous model. Simulated maximum groundwater ages of ∼1 Myrs below the central and coastal plain indicate that residual groundwater may be retained in the deep parts of the basin since being recharged during the last glacial period or earlier. The groundwater flow system has therefore probably not reached a new equilibrium state with modern-day hydraulic conditions. The

  4. Paleoenvironmental reconstruction based on palynofacies analyses of the Cansona Formation (Late Cretaceous), Sinú-San Jacinto Basin, northwest Colombia

    Science.gov (United States)

    Juliao-Lemus, Tatiana; Carvalho, Marcelo de Araujo; Torres, Diego; Plata, Angelo; Parra, Carlos

    2016-08-01

    To reconstruct the paleoenvironments of the Cansona Formation, a Cretaceous succession in Colombia that has controversial paleoenvironmental interpretation, occasionally deep marine and occasionally shallow marine, palynofacies analyses were conducted on 93 samples from four sections of the Sinú San Jacinto Basin in the north, midwest, and southwest sectors. For the palynofacies analyses, the kerogen categories were counted and subjected to cluster analyses. Four palynofacies associations were revealed for the four sections: Palynofacies Association I (PA I), which consisted of microforaminiferal linings, scolecodonts, dinoflagellate cysts, pollen grains, and fungi hyphae; PA II, which consisted of phytoclast translucent non-biostructured and biostructured, opaque phytoclasts (equidimensional and lath shaped); PA III, which consisted of pseudoamorphous particles, cuticles, resin, and fungal spores; and PA IV, which consisted of fluorescent and non-fluorescent amorphous organic matter and the fresh-water algae Botryococcus. In contrast to early studies that suggested a generalization of the depositional environment for the Cansona Formation (deep or shallow conditions), this study suggests that the formation reflects conspicuous stratigraphic and lateral changes and hence different depositional environments. The Cerro Cansona (CC4 section) and Chalán (AP section) areas are a more marine proximal settings (Early Campanian-Maastrichtian), and there is an intermediate setting for the Lorica area (SC section) and deeper conditions for the Montería area (CP2 section).

  5. 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

  6. Division of Gas Accumulation System and Laws Controlling Distribution of Natural Gas in Typical Petroliferous Basins of China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Considering the existing problems of the petroleum system, this paper brings forward the concept of natural gas accumulation system and presents the dividing principles. Then detailed statistics on the accumulation factors of the 32 typical natural gas accumulation systems in China and studies on the laws controlling distribution of gas are collected. The research shows that the petroleum accumulation system is the basic unit controlling petroleum generation, migration and accumulation. Generating intensity, generating amount, accumulating efficiency and migration distance plays an important role in the distribution of natural gas. Through analysis on results of resources evaluation, discovered reserves and residual reserves, potential areas in middle-scaled petroliferous basins in China are forecasted in this paper. Ordos, Sichuan, Tarim and Qaidam basins are found out to be the main basins developing and enriching gas accumulation systems.

  7. 中国及邻区中新生代大型大陆扩张盆地及其造山作用(续)%Meso-Cenozoic great continental spreading