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Sample records for plateau region china

  1. Climate and land use controls on soil organic carbon in the loess plateau region of China.

    Science.gov (United States)

    Dang, Yaai; Ren, Wei; Tao, Bo; Chen, Guangsheng; Lu, Chaoqun; Yang, Jia; Pan, Shufen; Wang, Guodong; Li, Shiqing; Tian, Hanqin

    2014-01-01

    The Loess Plateau of China has the highest soil erosion rate in the world where billion tons of soil is annually washed into Yellow River. In recent decades this region has experienced significant climate change and policy-driven land conversion. However, it has not yet been well investigated how these changes in climate and land use have affected soil organic carbon (SOC) storage on the Loess Plateau. By using the Dynamic Land Ecosystem Model (DLEM), we quantified the effects of climate and land use on SOC storage on the Loess Plateau in the context of multiple environmental factors during the period of 1961-2005. Our results show that SOC storage increased by 0.27 Pg C on the Loess Plateau as a result of multiple environmental factors during the study period. About 55% (0.14 Pg C) of the SOC increase was caused by land conversion from cropland to grassland/forest owing to the government efforts to reduce soil erosion and improve the ecological conditions in the region. Historical climate change reduced SOC by 0.05 Pg C (approximately 19% of the total change) primarily due to a significant climate warming and a slight reduction in precipitation. Our results imply that the implementation of "Grain for Green" policy may effectively enhance regional soil carbon storage and hence starve off further soil erosion on the Loess Plateau.

  2. Prediction of Bulk Density of Soils in the Loess Plateau Region of China

    Science.gov (United States)

    Wang, Yunqiang; Shao, Ming'an; Liu, Zhipeng; Zhang, Chencheng

    2013-08-01

    Soil bulk density (BD) is a key soil physical property that may affect the transport of water and solutes and is essential to estimate soil carbon/nutrients reserves. However, BD data are often lacking in soil databases due to the challenge of directly measuring BD, which is considered to be labor intensive, time consuming, and expensive especially for the lower layers of deep soils such as those of the Chinese Loess Plateau region. We determined the factors that were closely correlated with BD at the regional scale and developed a robust pedotransfer function (PTF) for BD by measuring BD and potentially related soil and environmental factors at 748 selected sites across the Loess Plateau of China (620,000 km2) at which we collected undisturbed and disturbed soil samples from two soil layers (0-5 and 20-25 cm). Regional BD values were normally distributed and demonstrated weak spatial variation (CV = 12 %). Pearson's correlation and stepwise multiple linear regression analyses identified silt content, slope gradient (SG), soil organic carbon content (SOC), clay content, slope aspect (SA), and altitude as the factors that were closely correlated with BD and that explained 25.8, 6.3, 5.8, 1.4, 0.3, and 0.3 % of the BD variation, respectively. Based on these closely correlated variables, a reasonably robust PTF was developed for BD using multiple linear regression, which performed equally with the artificial neural network method in the current study. The inclusion of topographic factors significantly improved the predictive capability of the BD PTF and in which SG was an important input variable that could be used in place of SA and altitude without compromising its capability for predicting BD. Thus, the developed PTF with only four input variables (clay, silt, SOC, SG), including their common transformations and interactive terms, predicted BD with reasonable accuracy and is thus useful for most applications on the Loess Plateau of China. More attention should be

  3. Regional effects of vegetation restoration on water yield across the Loess Plateau, China

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    X. M. Feng

    2012-08-01

    Full Text Available The general relationships between vegetation and water yield under different climatic regimes are well established at a small watershed scale in the past century. However, applications of these basic theories to evaluate the regional effects of land cover change on water resources remain challenging due to the complex interactions of vegetation and climatic variability and hydrologic processes at the large scale. The objective of this study was to explore ways to examine the spatial and temporal effects of a large ecological restoration project on water yield across the Loess Plateau region in northern China. We estimated annual water yield as the difference between precipitation input and modelled actual evapotranspiration (ET output. We constructed a monthly ET model using published ET data derived from eddy flux measurements and watershed streamflow data. We validated the ET models at a watershed and regional levels. The model was then applied to examine regional water yield under land cover change and climatic variability during the implementation of the Grain-for-Green (GFG project during 1999–2007. We found that water yield in 38% of the Loess Plateau area might have decreased (1–48 mm per year as a result of land cover change alone. However, combined with climatic variability, 37% of the study area might have seen a decrease in water yield with a range of 1–54 mm per year, and 35% of the study area might have seen an increase with a range of 1–10 mm per year. Across the study region, climate variability masked or strengthened the water yield response to vegetation restoration. The absolute annual water yield change due to vegetation restoration varied with precipitation regimes with the highest in wet years, but the relative water yield changes were most pronounced in dry years. We concluded that the effects of land cover change associated with ecological restoration varied greatly over time and space and were strongly influenced

  4. Attribution analysis of runoff decline in a semiarid region of the Loess Plateau, China

    Science.gov (United States)

    Li, Binquan; Liang, Zhongmin; Zhang, Jianyun; Wang, Guoqing; Zhao, Weimin; Zhang, Hongyue; Wang, Jun; Hu, Yiming

    2016-12-01

    runoff decline. This study enhances our understanding of runoff changes caused by SWC measures and climate variability in the typical semiarid region of Loess Plateau, China.

  5. Regional Evaluation of Wind Erosion of the Loess Plateau in Pengyang County, Ningxia Hui Autonomous Region, China

    Institute of Scientific and Technical Information of China (English)

    Sun Baoping; Ding Guodong; Li Yubao

    2003-01-01

    The loess plateau in China is well-known for its severe water erosion. A nationwide soil erosion survey discovered that wind erosion of the loess land is also greatly concerned. The severity of wind erosion for each land use in Pengyang County of Ningxia Hui Autonomous Region, China, was evaluated according to the national standard of soil erosion classification. The evaluation system includes a GIS database, an evaluation indicator system and a classification system for land and land use. The erodible nature of soil and annual soil loss of the most erodible land were obtained as follows: (1) Croplands plowed and harrowed in late autumn were the most erodible land,with an erosion intensity of medium grade and an erodible proportion of 46%; (2) The erodible proportion of natural grasslands was between 19.3% and 21.5%, whose erosion intensity was of mostly tolerable grade; (3) When it came to the whole county, there was 21.3% of the total area in tolerable grade in terms of wind erosion intensity, 42.1% slight and 34.8% medium.

  6. Quantitative Assessment of Desertification Using Landsat Data on a Regional Scale – A Case Study in the Ordos Plateau, China

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    Jianjun Pan

    2009-03-01

    Full Text Available Desertification is a serious threat to the ecological environment and social economy in our world and there is a pressing need to develop a reasonable and reproducible method to assess it at different scales. In this paper, the Ordos Plateau in China was selected as the research region and a quantitative method for desertification assessment was developed by using Landsat MSS and TM/ETM+ data on a regional scale. In this method, NDVI, MSDI and land surface albedo were selected as assessment indicators of desertification to represent land surface conditions from vegetation biomass, landscape pattern and micrometeorology. Based on considering the effects of vegetation type and time of images acquired on assessment indictors, assessing rule sets were built and a decision tree approach was used to assess desertification of Ordos Plateau in 1980, 1990 and 2000. The average overall accuracy of three periods was higher than 90%. The results showed that although some local places of Ordos Plateau experienced an expanding trend of desertification, the trend of desertification of Ordos Plateau was an overall decrease in from 1980 to 2000. By analyzing the causes of desertification processes, it was found that climate change could benefit for the reversion of desertification from 1980 to 1990 at a regional scale and human activities might explain the expansion of desertification in this period; however human conservation activities were the main driving factor that induced the reversion of desertification from 1990 to 2000.

  7. Seed population dynamics on abandoned slopes in the hill and gully Loess Plateau region of China

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    Yu, Weijie; Jiao, Juying

    2017-04-01

    Recovery of natural vegetation is an effective but slow approach to control the soil erosion in the Chinese hill and gully Loess Plateau region. As seed stage is particularly vulnerable to environmental conditions, characteristics of seed population should be needed to study for determining whether the recovery of natural vegetation is limited during this stage on the abandoned slopes in this region. The study was performed on three abandoned slopes in a watershed with an area of 8.27 km2in the Shaanxi province of China. The differences in soil seed banks were investigated in two different points in time, late March2011 and early April 2013. Main factors of seed population dynamics, such as seed yield of dominant species, seed inputs by seed rain as well as seed outputs through seed loss by overland flow and seedling emergence, were monitored from late March 2011 to early April 2013. In this study, seed rain densities of the main later successional species, i.e., Lespedeza davurica, Stipa bungeana and Artemisia gmelinii accounted for 51.5-71.6% of their own seed yields. The soil seed bank density in early April 2013 was larger than that in late March 2011. The density of seed inputs by seed rain was 10186 seeds•m-2, and the total seed bank, including seed rain and seeds present in the soil seed bank in late March 2011, reached a density of 15018 seeds•m-2 during the study period. Seed densities of loss due to overland flow and seedling emergence were 79 seeds•m-2 from 20 species and 938 seedlings•m-2 that belonged to 38 species during a study period, and the seed output through them accounted for 0.5% and 6.3% of the total seed bank, respectively. The study concluded that overland flow could not result in large numbers of seeds loss and seeds were accumulating in the soil seed bank due to seed rain, and vegetation succession might be limited by curbed spatial seed dispersal and seedling establishment.

  8. Quantifying the effect of ecological restoration on soil erosion in China's Loess Plateau region: an application of the MMF approach.

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    Li, Changbin; Qi, Jiaguo; Feng, Zhaodong; Yin, Runsheng; Guo, Biyun; Zhang, Feng; Zou, Songbing

    2010-03-01

    Land degradation due to erosion is one of the most serious environmental problems in China. To reduce land degradation, the government has taken a number of conservation and restoration measures, including the Sloping Land Conversion Program (SLCP), which was launched in 1999. A logical question is whether these measures have reduced soil erosion at the regional level. The objective of this article is to answer this question by assessing soil erosion dynamics in the Zuli River basin in the Loess Plateau of China from 1999 to 2006. The MMF (Morgan, Morgan and Finney) model was used to simulate changes in runoff and soil erosion over the period of time during which ecological restoration projects were implemented. Some model variables were derived from remotely sensed images to provide improved land surface representation. With an overall accuracy rate of 0.67, our simulations show that increased ground vegetation cover, especially in forestlands and grasslands, has reduced soil erosion by 38.8% on average from 1999 to 2006. During the same time period, however, the change in rainfall pattern has caused a 13.1% +/- 4.3% increase in soil erosion, resulting in a net 25.7% +/- 8.5% reduction in soil erosion. This suggests that China's various ecological restoration efforts have been effective in reducing soil loss.

  9. Subpixel Inundation Mapping Using Landsat-8 OLI and UAV Data for a Wetland Region on the Zoige Plateau, China

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    Haoming Xia

    2017-01-01

    Full Text Available Wetland inundation is crucial to the survival and prosperity of fauna and flora communities in wetland ecosystems. Even small changes in surface inundation may result in a substantial impact on the wetland ecosystem characteristics and function. This study presented a novel method for wetland inundation mapping at a subpixel scale in a typical wetland region on the Zoige Plateau, northeast Tibetan Plateau, China, by combining use of an unmanned aerial vehicle (UAV and Landsat-8 Operational Land Imager (OLI data. A reference subpixel inundation percentage (SIP map at a Landsat-8 OLI 30 m pixel scale was first generated using high resolution UAV data (0.16 m. The reference SIP map and Landsat-8 OLI imagery were then used to develop SIP estimation models using three different retrieval methods (Linear spectral unmixing (LSU, Artificial neural networks (ANN, and Regression tree (RT. Based on observations from 2014, the estimation results indicated that the estimation model developed with RT method could provide the best fitting results for the mapping wetland SIP (R2 = 0.933, RMSE = 8.73% compared to the other two methods. The proposed model with RT method was validated with observations from 2013, and the estimated SIP was highly correlated with the reference SIP, with an R2 of 0.986 and an RMSE of 9.84%. This study highlighted the value of high resolution UAV data and globally and freely available Landsat data in combination with the developed approach for monitoring finely gradual inundation change patterns in wetland ecosystems.

  10. Species Composition, Richness and Aboveground Biomass of Natural Grassland in Hilly-Gully Regions of the Loess Plateau, China

    Institute of Scientific and Technical Information of China (English)

    DENG Lei; SHANGGUAN; Zhou-ping

    2014-01-01

    In order to study the characteristics of species composition, richness and aboveground biomass of natural grasslands, and then ifnd out the relations between species richness and aboveground productivity of the communities and possible mechanisms to form the relations, four typical grassland communities (Artemisia capillaries (AC), Thymus quinquecostatus (TQ), Stipa bungeana (SB) and Stipa grandis (SG)) along with a succession sequence in hilly-gully regions of the Loess Plateau, China, were investigated by ifeld survey and laboratory analysis. The results were summarized as follows:Different succession stages had different species compositions as well as different proportions of plant life forms and photosynthetic types, and Asteraceae, Poaceae and Leguminosae were their dominant species as well as their dominant perennial herb species;and different succession stages had signiifcantly different species richness and aboveground biomasses. There were many relation patterns (linear positive correlation, unrelated relations and unimodal relations) between the species richness and aboveground biomass in different succession stages and a signiifcant unimodal relation between the species richness and aboveground biomass in all the grassland communities and the highest species diversity appeared at a moderate level of productivity. The results suggest the unimodal relations in all the grassland communities are accumulative results of the relations in each succession stage.

  11. [Effects of revegetation on organic carbon storage in deep soils in hilly Loess Plateau region of Northwest China].

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    Zhang, Jin; Xu, Ming-Xiang; Wang, Zheng; Ma, Xin-Xin; Qiu, Yu-Jie

    2012-10-01

    Taking the Robinia pseudoacacia woodlands, Caragana korshinskii shrublands, and abandoned croplands with different years of revegetation in the hilly Loess Plateau region of Northwest China as test objects, this paper studied the profile distribution and accumulation dynamics of organic carbon storage in deep soil (100-400 cm), with those in 0-100 cm soil profile as the control. In 0-100 cm soil profile, the organic carbon storage decreased significantly with the increase of soil depth; while in deep soil, the organic carbon storage had a slight fluctuation. The total organic carbon storage in 100-400 cm soil profile was considerably high, accounting for approximately 60% of that in 0-400 cm soil profile. The organic carbon storage in 80-100 cm soil layer had a significant linear correlation with that in 100-200 and 200-400 cm soil layers, and among the organic carbon storages in the five layers in 0-100 cm soil profile, the organic carbon storage in 80-100 cm soil layer had the strongest correlation with that in 100-400 cm soil profile, being able to be used to estimate the organic carbon storage in deep soil in this region. The organic carbon storage in 0-20 cm soil layer in the three types of revegetation lands was significantly higher than that in slope croplands, but the organic carbon storage in deep soil had no significant difference among the land use types. The organic carbon storage in deep soil increased with the increasing years of revegetation. In R. pseudoacacia woodlands and C. korshinskii shrub lands, the average increasing rate of the organic carbon storage in 100-400 cm soil layer was 0.14 and 0.19 t x hm(-2) x a(-1), respectively, which was comparable to that in the 0-100 cm soil layer in C. korshinskii shrublands. It was suggested that in the estimation of the soil carbon sequestration effect of revegetation in hilly Loess Plateau region, the organic carbon accumulation in deep soil should be taken into consideration. Otherwise, the effect of

  12. [Analysis of sap flow characteristics of the Chinese pine in typical Loess Plateau Region of China].

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    Zhang, Han-dan; Wei, Wei; Chen, Li-ding; Yu, Yang; Yang, Lei; Jia, Fu-yan

    2015-01-01

    Transpiration is one of the major processes of water consumption. It is significant for nutrients transportation, plant development, drought stress alleviation and micro-climate amelioration. In this study, the artificially planted Chinese pine (Pinus tabuliformis) was selected as an example to explore its transpiration characteristics, water-use strategies and the adaptability of the living environment in a typical loess hilly area of China. The results showed that: the sap flow rates of Chinese pine varied obviously in different seasons. The minimum sap flow rate occurred in April, followed by October, September and August, which was 0.024, 0.057, 0.062 and 0.071 mL x (cm2 x min)(-1), respectively. The rule of the diurnal variation of sap flow rate was regular, higher in daytime than at night. The flow rate was low during nighttime, but not zero. In rainfall events, the proportion of sap flow during nighttime was significantly increased, which was 3.9 times of that on sunny days, with 31.8% decrease in daytime. Chinese pine had great adaptability to unexpected climates. The variation trend of flow rate in the clod was similar to that on rainy days. The sap flow velocity was in great relevance with meteorological factors, with a declining order of solar radiation, vapor pressure deficit, relative humidity, and atmospheric temperature.

  13. Impact of climate variability and anthropogenic activity on streamflow in the Three Rivers Headwater Region, Tibetan Plateau, China

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    Jiang, Chong; Li, Daiqing; Gao, Yanni; Liu, Wenfeng; Zhang, Linbo

    2016-05-01

    Under the impacts of climate variability and human activities, there is violent fluctuation for streamflow in the large basins in China. Therefore, it is crucial to separate the impacts of climate variability and human activities on streamflow fluctuation for better water resources planning and management. In this study, the Three Rivers Headwater Region (TRHR) was chosen as the study area. Long-term hydrological data for the TRHR were collected in order to investigate the changes in annual runoff during the period of 1956-2012. The nonparametric Mann-Kendall test, moving t test, Pettitt test, Mann-Kendall-Sneyers test, and the cumulative anomaly curve were used to identify trends and change points in the hydro-meteorological variables. Change point in runoff was identified in the three basins, which respectively occurred around the years 1989 and 1993, dividing the long-term runoff series into a natural period and a human-induced period. Then, the hydrologic sensitivity analysis method was employed to evaluate the effects of climate variability and human activities on mean annual runoff for the human-induced period based on precipitation and potential evapotranspiration. In the human-induced period, climate variability was the main factor that increased (reduced) runoff in LRB and YARB (YRB) with contribution of more than 90 %, while the increasing (decreasing) percentage due to human activities only accounted for less than 10 %, showing that runoff in the TRHR is more sensitive to climate variability than human activities. The intra-annual distribution of runoff shifted gradually from a double peak pattern to a single peak pattern, which was mainly influenced by atmospheric circulation in the summer and autumn. The inter-annual variation in runoff was jointly controlled by the East Asian monsoon, the westerly, and Tibetan Plateau monsoons.

  14. [Responses of plant functional traits to micro-topographical changes in hilly and gully region of the Loess Plateau, China].

    Science.gov (United States)

    Yang, Shi-suo; Wen, Zhong-ming; Miao, Lian-peng; Qi, De-hui; Hua, Dong-wen

    2014-12-01

    Plant functional traits are closely tied to the performance of plants in specific microenvironments, and reflect their ability to adapt to those microenvironments. In areas with complex topography, analyzing the responses of plant functional traits to microtopographical changes is crucial to understanding the adaptive strategies of plants in diverse environments. This paper analyzed fluctuations in soil nutrients as well as correlations between plant functional traits and changes in topography at the family and community levels in selected natural vegetation communities in the foreststeppe zone of the loess hilly and gully region in Loess Plateau of China. Significant differences in plant functional traits were primarily driven by the phylogenetic background or species composition of the community. Slope aspect exerted less impact while slope positions had no significant effect on plant traits at the community level. No significant changes in plant functional traits were observed with changes in topography at the community level. However, leaf nitrogen and root nitrogen contents of Leguminous and Compositae species differed significantly With slope positions. The root tissue density of Graminaceous species differed significantly with slope positions. Root density exhibited significant positive correlations with soil nutrient and carbon contents at the community level. Both leaf nitrogen and root nitrogen contents of Leguminous species were positively correlated with soil phosphorus content, while leaf nitrogen and root nitrogen contents of both Graminaceous and Compositae species were significantly positively related to soil nitrogen content. The results demonstrate the different responses of species of different families to changes in micro-topography and their distinctive adaptive strategies to the environment.

  15. Impact of climate variability and anthropogenic activity on streamflow in the Three Rivers Headwater Region, Tibetan Plateau, China

    Science.gov (United States)

    Jiang, Chong; Li, Daiqing; Gao, Yanni; Liu, Wenfeng; Zhang, Linbo

    2017-07-01

    Under the impacts of climate variability and human activities, there is violent fluctuation for streamflow in the large basins in China. Therefore, it is crucial to separate the impacts of climate variability and human activities on streamflow fluctuation for better water resources planning and management. In this study, the Three Rivers Headwater Region (TRHR) was chosen as the study area. Long-term hydrological data for the TRHR were collected in order to investigate the changes in annual runoff during the period of 1956-2012. The nonparametric Mann-Kendall test, moving t test, Pettitt test, Mann-Kendall-Sneyers test, and the cumulative anomaly curve were used to identify trends and change points in the hydro-meteorological variables. Change point in runoff was identified in the three basins, which respectively occurred around the years 1989 and 1993, dividing the long-term runoff series into a natural period and a human-induced period. Then, the hydrologic sensitivity analysis method was employed to evaluate the effects of climate variability and human activities on mean annual runoff for the human-induced period based on precipitation and potential evapotranspiration. In the human-induced period, climate variability was the main factor that increased (reduced) runoff in LRB and YARB (YRB) with contribution of more than 90 %, while the increasing (decreasing) percentage due to human activities only accounted for less than 10 %, showing that runoff in the TRHR is more sensitive to climate variability than human activities. The intra-annual distribution of runoff shifted gradually from a double peak pattern to a single peak pattern, which was mainly influenced by atmospheric circulation in the summer and autumn. The inter-annual variation in runoff was jointly controlled by the East Asian monsoon, the westerly, and Tibetan Plateau monsoons.

  16. Regional effects of vegetation restoration on water yield across the Loess Plateau, China

    Science.gov (United States)

    X. M. Feng; G. Sun; B. J. Fu; C. H. Su; Y. Liu; H. Lamparski

    2012-01-01

    The general relationships between vegetation and water yield under different climatic regimes are well established at a small watershed scale in the past century. However, applications of these basic theories to evaluate the regional effects of land cover change on water resources remain challenging due to the complex interactions of vegetation and climatic variability...

  17. Quantifying the Effects of Conservation Practices on Soil, Water, and Nutrients in the Loess Mesa Ravine Region of the Loess Plateau, China

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    Xu, Xiang-Zhou; Li, Mei-Juan; Liu, Bin; Kuang, Shang-Fu; Xu, Shi-Guo

    2012-05-01

    A large number of soil and water conservation programs have been implemented on the Loess Plateau of China since the 1950s. To comprehensively assess the merits and demerits of the conservation practices is of great importance in further supervising the conservation strategy for the Loess Plateau. This study calculates the impact factors of conservation practices on soil, water, and nutrients during the period 1954-2004 in the Nanxiaohegou Catchment, a representative catchment in the Loess Mesa Ravine Region of the Loess Plateau, China. Brief conclusions could be drawn as follows: (1) Soil erosion and nutrient loss had been greatly mitigated through various conservation practices. About half of the total transported water and 94.8 % of the total transported soil and nutrients, had been locally retained in the selected catchment. The soil retained from small watersheds do not only form large-scale fertile farmland but also safeguard the Yellow River against overflow. (2) Check dam was the most appropriate conservation practice on the Loess Plateau. In the selected catchment, more than 90 % of the retained soil and water were accomplished by the dam farmland, although the dam farmland occupied only 2.3 % of the total area of all conservation measures. Retention abilities of the characteristic conservation practices were in the following order: dam farmland > terrace farmland > forest land and grassland. (3) The conservation practices were more powerful in retaining sediment than in reducing runoff from the Loess Plateau, and the negative effects of the conservation practices on reducing water to the Yellow River were relatively slight.

  18. Quantifying the effects of conservation practices on soil, water, and nutrients in the Loess Mesa Ravine Region of the Loess Plateau, China.

    Science.gov (United States)

    Xu, Xiang-Zhou; Li, Mei-Juan; Liu, Bin; Kuang, Shang-Fu; Xu, Shi-Guo

    2012-05-01

    A large number of soil and water conservation programs have been implemented on the Loess Plateau of China since the 1950s. To comprehensively assess the merits and demerits of the conservation practices is of great importance in further supervising the conservation strategy for the Loess Plateau. This study calculates the impact factors of conservation practices on soil, water, and nutrients during the period 1954-2004 in the Nanxiaohegou Catchment, a representative catchment in the Loess Mesa Ravine Region of the Loess Plateau, China. Brief conclusions could be drawn as follows: (1) Soil erosion and nutrient loss had been greatly mitigated through various conservation practices. About half of the total transported water and 94.8 % of the total transported soil and nutrients, had been locally retained in the selected catchment. The soil retained from small watersheds do not only form large-scale fertile farmland but also safeguard the Yellow River against overflow. (2) Check dam was the most appropriate conservation practice on the Loess Plateau. In the selected catchment, more than 90 % of the retained soil and water were accomplished by the dam farmland, although the dam farmland occupied only 2.3 % of the total area of all conservation measures. Retention abilities of the characteristic conservation practices were in the following order: dam farmland > terrace farmland > forest land and grassland. (3) The conservation practices were more powerful in retaining sediment than in reducing runoff from the Loess Plateau, and the negative effects of the conservation practices on reducing water to the Yellow River were relatively slight.

  19. An Indicator System for Assessing Soil Erosion in the Loess Plateau Gully Regions:A Case Study in the Wangdonggou Watershed, China

    Institute of Scientific and Technical Information of China (English)

    NI Shao-Xiang; MA Guo-Bin; WEI Yu-Chun; JIANG Hai-Fu

    2004-01-01

    The Wangdonggou Watershed on the Loess Plateau in China was selected as the study area to develop a model for soil erosion assessments. Using the data collected at 20 sampling sites all tentatively selected indicators were assessed against their corresponding erosion intensity through a correlation analysis. Eight highly correlated indicators were then chosen for the soil erosion assessment. In addition, threshold limits to delineate the class size for these indicators and weights to rank them were determined. Next, a grading model incorporating the selected indicators class rating and their associated weights was developed and verified by an on site evaluation of the soil erosion intensity in the study area. Results of the verification showed that the overall accuracy of the indicator system for assessing soil erosion in the Loess Plateau gully regions could reach 85%.

  20. [Effects of land use and environmental factors on the variability of soil quality indicators in hilly Loess Plateau region of China].

    Science.gov (United States)

    Xu, Ming-Xiang; Liu, Guo-Bin; Zhao, Yun-Ge

    2011-02-01

    Classical statistics methods were adopted to analyze the soil quality variability, its affecting factors, and affecting degree at a regional scale (700 km2) in the central part of hilly Loess Plateau region of China. There existed great differences in the variability of test soil quality indicators. Soil pH, structural coefficient, silt content, specific gravity, bulk density, total porosity, capillary porosity, and catalase activity were the indicators with weak variability; soil nutrients (N, P, and K) contents, CaCO3 content, cation exchange capacity (CEC), clay content, micro-aggregate mean mass diameter, aggregate mean mass diameter, water-stable aggregates, respiration rate, microbial quotient, invertase and phosphatase activities, respiratory quotient, and microbial carbon and nitrogen showed medium variation; while soil labile organic carbon and phosphorus contents, erosion-resistance, permeability coefficient, and urease activity were the indicators with strong variability. The variability of soil CaCO3, total P and K, CEC, texture, and specific gravity, etc. was correlated with topography and other environmental factors, while the variability of dynamic soil quality indicators, including soil organic matter content, nitrogen content, water-stable aggregates, permeability, microbial biomass carbon and nitrogen, enzyme activities, and respiration rate, was mainly correlated with land use type. Overall, land use pattern explained 97% of the variability of soil quality indicators in the region. It was suggested that in the evaluation of soil quality in hilly Loess Plateau region, land use type and environmental factors should be fully considered.

  1. Erosion Associated with Seismically-Induced Landslides in the Middle Longmen Shan Region, Eastern Tibetan Plateau, China

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    Zhikun Ren

    2017-08-01

    Full Text Available The 2008 Wenchuan earthquake and associated co-seismic landslide was the most recent expression of the rapid deformation and erosion occurring in the eastern Tibetan Plateau. The erosion associated with co-seismic landslides balances the long-term tectonic uplift in the topographic evolution of the region; however, the quantitative relationship between earthquakes, uplift, and erosion is still unknown. In order to quantitatively distinguish the seismically-induced erosion in the total erosion, here, we quantify the Wenchuan earthquake-induced erosion using the digital elevation model (DEM differential method and previously-reported landslide volumes. Our results show that the seismically-induced erosion is comparable with the pre-earthquake short-term erosion. The seismically-induced erosion rate contributes ~50% of the total erosion rate, which suggests that the local topographic evolution of the middle Longmen Shan region may be closely related to tectonic events, such as the 2008 Wenchuan earthquake. We propose that seismically-induced erosion is a very important component of the total erosion, particularly in active orogenic regions. Our results demonstrate that the remote sensing technique of differential DEM provides a powerful tool for evaluating the volume of co-seismic landslides produced in intermountain regions by strong earthquakes.

  2. Climate Change and Its Impact on the Eco-Environment of the Three-Rivers Headwater Region on the Tibetan Plateau, China.

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    Jiang, Chong; Zhang, Linbo

    2015-09-25

    This study analyzes the impact of climate change on the eco-environment of the Three-Rivers Headwater Region (TRHR), Tibetan Plateau, China. Temperature and precipitation experienced sharp increases in this region during the past 57 years. A dramatic increase in winter temperatures contributed to a rise in average annual temperatures. Moreover, annual runoff in the Lancang (LRB) and Yangtze (YARB) river basins showed an increasing trend, compared to a slight decrease in the Yellow River Basin (YRB). Runoff is predominantly influenced by rainfall, which is controlled by several monsoon systems. The water temperature in the YRB and YARB increased significantly from 1958 to 2007 (p runoff, with a maximum value observed in the 2000s.

  3. Multicriteria decision analysis for monitoring ecosystem service function of the Three-River Headwaters region of the Qinghai-Tibet Plateau, China.

    Science.gov (United States)

    Zhu, Jinfeng; Zhou, Yi; Wang, Shixin; Wang, Litao; Wang, Futao; Liu, Wenliang; Guo, Bing

    2015-06-01

    The Three-River Headwaters (TRH) region in the Qinghai-Tibet Plateau, China, is of key importance to the ecological security of China and Southeast Asia and contains some of the most sensitive and fragile ecosystems. Monitoring and evaluating the ecosystem service function and its changes in the TRH region could support decision-making for regional ecological protection and restoration programs. Referencing the concept of ecosystem service and the Millennium Ecosystem Assessment (MA) framework, this study built a system of indicators for monitoring and evaluating the ecosystem service function. Thus, combining a multicriteria decision analysis (MCDA) and weighted linear combination (WLC) with analytic hierarchy process (AHP), we applied the ecosystem service function index (ESFI) based on remote sensing data at 1-km spatial resolution to spatiotemporally monitor the changes during the period 2005-2010. The study results indicated that ESFI had a good performance for monitoring the ecosystem service function and showed an improving trend in the TRH region over the past 5 years. Ecosystem environment recovery not only reflected the changing trend of warm and wet climate but was also a response of the ecological protection project of the Key Ecological Function Zone in the TRH region.

  4. Factors Affecting Distribution of Vegetation Types on Abandoned Cropland in the Hilly-Gullied Loess Plateau Region of China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A study was conducted in the forest-steppe region of the Loess Plateau to provide insight into the factors affecting the process of vegetation establishment,and to provide recommendations for the selection of indigenous species in order to speed up the succession process and to allow the establishment of vegetation more resistant to soil erosion.Four distinctive vegetation types were identified,and their distribution was affected not only by the time since abandonment but also by other environmental factors,mainly soil water and total P in the upper soil layers.One of the vegetation types,dominated by Artemisia scoparia,formed the early successional stage after abandonment while the other three types formed later successional stages with their distribution determined by the soil water content and total P.It can be concluded that the selection of appropriate species for introduction to accelerate succession should be determined by the local conditions and especially the total P concentration and soil water content.

  5. Climate Change and Its Impact on the Eco-Environment of the Three-Rivers Headwater Region on the Tibetan Plateau, China

    Directory of Open Access Journals (Sweden)

    Chong Jiang

    2015-09-01

    Full Text Available This study analyzes the impact of climate change on the eco-environment of the Three-Rivers Headwater Region (TRHR, Tibetan Plateau, China. Temperature and precipitation experienced sharp increases in this region during the past 57 years. A dramatic increase in winter temperatures contributed to a rise in average annual temperatures. Moreover, annual runoff in the Lancang (LRB and Yangtze (YARB river basins showed an increasing trend, compared to a slight decrease in the Yellow River Basin (YRB. Runoff is predominantly influenced by rainfall, which is controlled by several monsoon systems. The water temperature in the YRB and YARB increased significantly from 1958 to 2007 (p < 0.001, driven by air temperature changes. Additionally, owing to warming and wetting trends in the TRHR, the net primary productivity (NPP and normalized difference vegetation index (NDVI showed significant increasing trends during the past half-century. Furthermore, although an increase in water erosion due to rainfall erosivity was observed, wind speeds declined significantly, causing a decline in wind erosion, as well as the frequency and duration of sandstorms. A clear regional warming trend caused an obvious increasing trend in glacier runoff, with a maximum value observed in the 2000s.

  6. Planation Surfaces on the Tibet Plateau, China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A planation hypothesis is proposed to explain landform evolution of the Tibet Plateau. A denudation threshold (T), the maximum potential denudation rate for a certain type of rock, is introduced to explain the combined effects of lithology and tectonics on landform evolution. If the tectonic uplifting rate (U) is equal to or less than the threshold rate (U ≤ T), the tectonic uplifting and terrain denudation are in dynamic equilibrium, and landforms are in a steady state. The end product should be planation surfaces whether the original landforms are fiat plains or deeply dissected mountains. If U > T, uplift and denudation are not able to reach a dynamic equilibrium state. The plateau surface is mostly underlain by soft rocks, such as the Mesozoic epimetamorphic argillites and Tertiary sedimentary rocks, while the mountain ranges comprise hard rocks, such as granite, gneiss and limestone. In soft rock regions, hills are low with a relative relief of mostly less than 100m and the slopes are gentle at a gradient of <200. In contrast, hills can maintain steep slopes in hard rock regions. The Tibet Plateau has been under an equilibrium condition between tectonic uplifting and denudation except for the mountain ranges. The plateau might have reached the present altitudes before the Quaternary.

  7. Environmental significance of mineral weathering and pedogenesis of loess on the southernmost Loess Plateau, China

    NARCIS (Netherlands)

    Huang, C.; Zhao, W.; Liu, F.; Tan, W.F.; Koopal, L.K.

    2011-01-01

    Soils derived from the Loess Plateau of China are regionally important and expression of the soil properties along the soil profile may be directly related to climate changes. The objective of this research was to analyze the clay mineral transformation of loess from the southernmost Loess Plateau,

  8. Effect of rainfall regime and slope on runoff in a gullied loess region on the Loess Plateau in China.

    Science.gov (United States)

    Fang, H Y; Cai, Q G; Chen, H; Li, Q Y

    2008-09-01

    Runoff was measured from seven plots with different slopes nested in Tuanshangou catchment on the Loess Plateau to study effect of slopes on runoff in relation to rainfall regimes. Based on nine years of field observation and K-mean clusters, 84 rainfall events were grouped into three rainfall regimes. Rainfall regime A is the group of events with strong rainfall intensity, high frequency, and short duration. Rainfall regime C consists of events with low intensity, long duration, and infrequent occurrence. Rainfall regime B is the aggregation of events of medium intensity and medium duration, and less frequent occurrence. The following results were found: (1) Different from traditional studies, runoff coefficient neither decreased nor increased, but presented peak value on the slope surfaces; (2) For individual plot, runoff coefficients induced by rainfall regime A were the highest, and those induced by rainfall regime C were the lowest; Downslope, the runoff coefficients induced by three rainfall regimes presented the same changing trend, although the peak value induced by regime A occurred on a shorter slope length compared to those by regime B and C; (3) Scale effect on runoff induced by rainfall regime A was the least, and that induced by rainfall regime C was the largest. These results can be explained by the interactions of crusting, soil moisture content, slope length and gradient, and erosion units, etc., in the context of different rainfall regimes.

  9. Excessive afforestation and soil drying on China's Loess Plateau

    Science.gov (United States)

    Zhang, Shulei; Yang, Dawen

    2017-04-01

    Afforestation and deforestation are human disturbances to vegetation, which have profound impacts on regional eco-hydrological processes, the water and carbon cycles, and consequently, ecosystem sustainability. Since 1999, large scale revegetation has been carried out across China's Loess Plateau following the "Grain-to-Green Program" implemented by the Chinese government. This revegetation, particularly with forest, has caused negative eco-hydrological consequences, including streamflow decline and soil drying. Here, we have used "ecosystem optimality theory" and satellite observations, to assess the water balance under the climate-defined optimal and actual vegetation cover during 1982-2010 and its responses to future climate change (2011-2050) over the Loess Plateau. Results show that the current vegetation cover (0.48 on average) has already exceeded the climate-defined optimal cover (0.43 on average) in the most recent decade, especially in the middle-to-east Loess Plateau, indicating that it is the widespread over-planting, which is primarily responsible for soil drying in the area. In addition, both the optimal vegetation cover and soil moisture tend to decrease under future climate scenarios. Our findings suggest that further revegetation on the Loess Plateau should be applied with caution. To maintain a sustainable eco-hydrological environment in the region, a revegetation threshold should be urgently set, to limit future planting.

  10. Mapping risk of plague in Qinghai-Tibetan Plateau, China.

    Science.gov (United States)

    Qian, Quan; Zhao, Jian; Fang, Liqun; Zhou, Hang; Zhang, Wenyi; Wei, Lan; Yang, Hong; Yin, Wenwu; Cao, Wuchun; Li, Qun

    2014-07-10

    Qinghai-Tibetan Plateau of China is known to be the plague endemic region where marmot (Marmota himalayana) is the primary host. Human plague cases are relatively low incidence but high mortality, which presents unique surveillance and public health challenges, because early detection through surveillance may not always be feasible and infrequent clinical cases may be misdiagnosed. Based on plague surveillance data and environmental variables, Maxent was applied to model the presence probability of plague host. 75% occurrence points were randomly selected for training model, and the rest 25% points were used for model test and validation. Maxent model performance was measured as test gain and test AUC. The optimal probability cut-off value was chosen by maximizing training sensitivity and specificity simultaneously. We used field surveillance data in an ecological niche modeling (ENM) framework to depict spatial distribution of natural foci of plague in Qinghai-Tibetan Plateau. Most human-inhabited areas at risk of exposure to enzootic plague are distributed in the east and south of the Plateau. Elevation, temperature of land surface and normalized difference vegetation index play a large part in determining the distribution of the enzootic plague. This study provided a more detailed view of spatial pattern of enzootic plague and human-inhabited areas at risk of plague. The maps could help public health authorities decide where to perform plague surveillance and take preventive measures in Qinghai-Tibetan Plateau.

  11. [Biological soil crust nitrogenase activity and its responses to hydro-thermic factors in different erosion regions on the Loess Plateau, China].

    Science.gov (United States)

    Ming, Jiao; Zhao, Yun-Ge; Xu, Ming-Xiang; Yang, Li-Na; Wang, Ai-Guo

    2013-07-01

    Based on field survey, the biological soil crusts at their stable development stage were collected from the water erosion region, water-wind erosion region, and wind erosion region on the Loess Plateau, aimed to study the effects of the variations of moisture and temperature on the crusts nitrogenase activity (NA). The NA of the crusts in the erosion regions decreased in the order of water erosion region (127.7 micromol x m(-2) x h(-1)) > water-wind erosion region (34.6 micromol x m(-2) x h(-1)) > wind erosion region (6.0 micromol x m(-2) x h(-1)), and the optimal temperature for the crust nitrogen fixation was 35 degrees C, 25 degrees C, and 15 degrees C, respectively. At the optimal temperature and 100% -40% field water-holding capacity, the NA of the crusts from the water erosion and water-wind erosion regions had no significant difference. The NA of the crusts from the wind erosion region was more sensitive to the variation of moisture, showing a dramatic decline when the moisture decreased to 80% field water-holding capacity, and totally lost when the moisture decreased to 20% field water-holding capacity. The differences in the NA of the crusts from the three erosion regions and the responses of the NA to the variations of moisture and temperature were likely associated with the climate, environment, and the crust species composition.

  12. The impacts of the summer plateau monsoon over the Tibetan Plateau on the rainfall in the Tarim Basin, China

    Science.gov (United States)

    Zhao, Yong; Huang, Anning; Zhou, Yang; Yang, Qing

    2016-10-01

    The impacts of the summer plateau monsoon (PM) over the Tibetan Plateau on summer rainfall over the Tarim Basin in northwest China are investigated, based on the observed rainfall data at 34 stations and the NCEP/NCAR reanalysis data during 1961 to 2007. Results showed that the PM is well correlated to the summer rainfall over the Tarim Basin. Process analysis shows that strong PM corresponds to an anomalous cyclone over the Tibetan Plateau in the middle troposphere and an anomalous anticyclone in the upper troposphere over northwest part of Tibetan Plateau. They result in cold air moving from high latitudes into Central Asia over the western part of Tibetan Plateau. The concurrences of the cooling in the middle-upper troposphere over Central Asia leads to an anomalous cyclone over Central Asia at 500 hPa and the anomalous descending motions prevailing over the cooling region. Associated with this anomaly, there are enhanced southerly winds and corresponding ascending motion over the Tarim Basin located in the east of the cooling region. These processes lead to more summer rainfall over the Tarim Basin.

  13. Soil carbon sequestration potential for "grain for green" project in Loess Plateau, China

    Science.gov (United States)

    Chang, R.; Fu, B.; Liu, Gaisheng; Liu, S.

    2011-01-01

    Conversion of cropland into perennial vegetation land can increase soil organic carbon (SOC) accumulation, which might be an important mitigation measure to sequester carbon dioxide from the atmosphere. The "Grain for Green" project, one of the most ambitious ecological programmes launched in modern China, aims at transforming the low-yield slope cropland into grassland and woodland. The Loess Plateau in China is the most important target of this project due to its serious soil erosion. The objectives of this study are to answer three questions: (1) what is the rate of the SOC accumulation for this "Grain for Green" project in Loess Plateau? (2) Is there a difference in SOC sequestration among different restoration types, including grassland, shrub and forest? (3) Is the effect of restoration types on SOC accumulation different among northern, middle and southern regions of the Loess Plateau? Based on analysis of the data collected from the literature conducted in the Loess Plateau, we found that SOC increased at a rate of 0.712 TgC/year in the top 20 cm soil layer for 60 years under this project across the entire Loess Plateau. This was a relatively reliable estimation based on current data, although there were some uncertainties. Compared to grassland, forest had a significantly greater effect on SOC accumulation in middle and southern Loess Plateau but had a weaker effect in the northern Loess Plateau. There were no differences found in SOC sequestration between shrub and grassland across the entire Loess Plateau. Grassland had a stronger effect on SOC sequestration in the northern Loess Plateau than in the middle and southern regions. In contrast, forest could increase more SOC in the middle and southern Loess Plateau than in the northern Loess Plateau, whereas shrub had a similar effect on SOC sequestration across the Loess Plateau. Our results suggest that the "Grain for Green" project can significantly increase the SOC storage in Loess Plateau, and it is

  14. Soil carbon sequestration potential for "Grain for Green" project in Loess Plateau, China.

    Science.gov (United States)

    Chang, Ruiying; Fu, Bojie; Liu, Guohua; Liu, Shuguang

    2011-12-01

    Conversion of cropland into perennial vegetation land can increase soil organic carbon (SOC) accumulation, which might be an important mitigation measure to sequester carbon dioxide from the atmosphere. The "Grain for Green" project, one of the most ambitious ecological programmes launched in modern China, aims at transforming the low-yield slope cropland into grassland and woodland. The Loess Plateau in China is the most important target of this project due to its serious soil erosion. The objectives of this study are to answer three questions: (1) what is the rate of the SOC accumulation for this "Grain for Green" project in Loess Plateau? (2) Is there a difference in SOC sequestration among different restoration types, including grassland, shrub and forest? (3) Is the effect of restoration types on SOC accumulation different among northern, middle and southern regions of the Loess Plateau? Based on analysis of the data collected from the literature conducted in the Loess Plateau, we found that SOC increased at a rate of 0.712 TgC/year in the top 20 cm soil layer for 60 years under this project across the entire Loess Plateau. This was a relatively reliable estimation based on current data, although there were some uncertainties. Compared to grassland, forest had a significantly greater effect on SOC accumulation in middle and southern Loess Plateau but had a weaker effect in the northern Loess Plateau. There were no differences found in SOC sequestration between shrub and grassland across the entire Loess Plateau. Grassland had a stronger effect on SOC sequestration in the northern Loess Plateau than in the middle and southern regions. In contrast, forest could increase more SOC in the middle and southern Loess Plateau than in the northern Loess Plateau, whereas shrub had a similar effect on SOC sequestration across the Loess Plateau. Our results suggest that the "Grain for Green" project can significantly increase the SOC storage in Loess Plateau, and it is

  15. Change of precipitation characteristics in the water-wind erosion crisscross region on the Loess Plateau, China, from 1958 to 2015.

    Science.gov (United States)

    Zhao, Xingkai; Li, Zengyao; Zhu, Qingke

    2017-08-14

    Precipitation plays an important and crucial role in processes in the water-wind erosion crisscross region of the Loess Plateau than in other parts of the region. We analyzed precipitation data and standardized precipitation index (SPI) at 14 representative synoptic stations from 1958 to 2015 used trend-free prewhitening, linear trend estimation, Spearman's rho test, the Mann-Kendall trend test, the Mann-Kendall abrupt change test and rescaled range analysis. The following conclusions were drawn. First, the analysis of monthly precipitation at all stations suggested that precipitation during the rainy season (July, August, September), especially rain in July and August, exhibited a general decreasing trend, while both increasing and decreasing trends were observed in other months. Moreover, the annual precipitation of all stations continued to exhibit decreasing trends except Wuzhai. Erosive rainfall frequency in the rainy season and the annual scale was weakly reduced but erosive force of single rainfall has been enhanced. Second, the SPI exhibited different increasing degrees in winter, while decreasing trends were observed in other seasons. Additionally, the annual-scale SPI at most stations exhibited a stable and sustained downward trend. Therefore, this region is currently associated with a drought trend, and the drought degree will likely continue to increase.

  16. Impacts of climate change on glacial water resources and hydrological cycles in the Yangtze River source region,the Qinghai-Tibetan Plateau,China:A Progress Report

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    annual distribution of runoff in the source region.The annual glacial meltwater runoff in the Yangtze River Source Region is projected to increase by 28.5 percent by 2050 over its 1970 value with the projected temperature increase of 2℃ and a precipitation increase of 29 mm.As a critical source of surface water for agriculture on the eastern Qinghai-Tibet Plateau and beyond,the mass retreat of glaciers in the Yangtze River Source Region will have enormous negative impacts on farming and livestock-raising ac-tivities in upper Yangtze River watershed,as well as on the viability of present ecosystems and even socioeconomic development in the upper Yangtze River Basin.

  17. [Effects of land use change on soil active organic carbon in deep soils in Hilly Loess Plateau region of Northwest China].

    Science.gov (United States)

    Zhang, Shuai; Xu, Ming-Xiang; Zhang, Ya-Feng; Wang, Chao-Hua; Chen, Gai

    2015-02-01

    Response of soil active organic carbon to land-use change has become a hot topic in current soil carbon and nutrient cycling study. Soil active organic carbon distribution characteristics in soil profile under four land-use types were investigated in Ziwuling forest zone of the Hilly Loess Plateau region. The four types of land-use changes included natural woodland converted into artificial woodland, natural woodland converted into cropland, natural shrubland converted into cropland and natural shrubland converted into revegetated grassland. Effects of land-use changes on soil active organic carbon in deep soil layers (60-200 cm) were explored by comparison with the shallow soil layers (0-60 cm). The results showed that: (1) The labile organic carbon ( LOC) and microbial carbon (MBC) content were mainly concentrated in the shallow 0-60 cm soil, which accounted for 49%-66% and 71%-84% of soil active organic carbon in the profile (0-200 cm) under different land-use types. Soil active organic carbon content in shallow soil was significantly varied for the land-use changes types, while no obvious difference was observed in soil active organic carbon in deep soil layer. (2) Land-use changes exerted significant influence on soil active organic carbon, the active organic carbon in shallow soil was more sensitive than that in deep soil. The four types of land-use changes, including natural woodland to planted woodland, natural woodland to cropland, natural shrubland to revegetated grassland and natural shrubland to cropland, LOC in shallow soil was reduced by 10%, 60%, 29%, 40% and LOC in the deep layer was decreased by 9%, 21%, 12%, 1%, respectively. MBC in the shallow soil was reduced by 24% 73%, 23%, 56%, and that in the deep layer was decreased by 25%, 18%, 8% and 11%, respectively. (Land-use changes altered the distribution ratio of active organic carbon in soil profile. The ratio between LOC and SOC in shallow soil increased when natural woodland and shrubland were

  18. Phylogeography of regional fauna on the Tibetan Plateau: A review

    Institute of Scientific and Technical Information of China (English)

    Shujuan Yang; Hailiang Dong; Fumin Lei

    2009-01-01

    The studies of uplift and glaciations of the Tibetan Plateau are summarized, and a series of recent case studies of the endemic species based on DNA sequences are detailed. In general, these molecular data show that all the organisms originated from Early Pliocene to Late Miocene, and then multi-stages of divergence/speciation occurred within each taxa following their original occupation on the pla-teau, mainly as a result of periodic glacial cycles and geographic isolation. The regional fauna may have undergone several range con-tractions and expansions during the Pleistocene glaciations. However, the population expansion and refugia may vary in space, time, and extent. The regional fauna of the Tibetan Plateau may be combinations of ancient movement from adjacent zoogeographical regions, speciation in situ, and postglacial colonization from adjacent areas. Geomorphic and climatic changes on the plateau definitely have a remarkable influence on the regional and adjacent biogeographic patterns, and the mechanism is very complex.

  19. Soil moisture decline due to afforestation across the Loess Plateau, China

    Science.gov (United States)

    Jia, Xiaoxu; Shao, Ming'an; Zhu, Yuanjun; Luo, Yi

    2017-03-01

    The Loess Plateau of China is a region with one of the most severe cases of soil erosion in the world. Since the 1950s, there has been afforestation measure to control soil erosion and improve ecosystem services on the plateau. However, the introduction of exotic tree species (e.g., R. pseudoacacia, P. tabulaeformis and C. korshinskii) and high-density planting has had a negative effect on soil moisture content (SMC) in the region. Any decrease in SMC could worsen soil water shortage in both the top and deep soil layers, further endangering the sustainability of the fragile ecosystem. This study analyzed the variations in SMC following the conversion of croplands into forests in the Loess Plateau. SMC data within the 5-m soil profile were collected at 50 sites in the plateau region via field survey, long-term in-situ observations and documented literature. The study showed that for the 50 sites, the depth-averaged SMC was much lower under forest than under cropland. Based on in-situ measurements of SMC in agricultural plots and C. korshinskii plots in 2004-2014, SMC in the 0-4 m soil profile in both plots declined significantly (p water and require less thinning for sustainable soil conservation without compromising future water resources demands in the Loess Plateau.

  20. Evolution of Chinese mammalian faunal regions and elevation of the Qinghai-Xizang (Tibet) Plateau

    Institute of Scientific and Technical Information of China (English)

    QIU Zhuding; LI Chuankui

    2005-01-01

    On the basis of mammal's high evolutionary rates and sensitivity to environment, this paper deals with the evolutionary history of the Chinese Cenozoic mammals and environmental changes, and explores the relationship between the uplift of the Qinghai-Xizang Plateau and the evolution of zoogeographic provinces of China, through studying fossil mammal and the lithological characters of fossil-bearing beds. Evolutionary tendency and distribution of the mammals demonstrate that the uplift of the Qinghai-Xizang region, onset of the Asian monsoon and differentiation of the mammalian distribution probably initiated in Oligocene. The elevation of the Plateau seems to be a gradual and relatively stable process, and the uplift not only has resulted in significant environmental changes in Asia, but also caused distinct regional differentiation of mammals in China since the middle Miocene, and as a consequence the modern zoogeographic provinces gradually took shape.

  1. Fractal Characteristics of Soil under Different Land-Use Patterns in the Arid and Semi-Arid Region of the Western Tibet Plateau, China

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-dan; LIU Shu-zhen; LIU Gang-cai

    2005-01-01

    The fractal geometry to the study of soil structure, its dynamics, and physical processes appears to be a useful tool in reaching a better understanding of system performance. This research was designed to apply fractal models for mass into computing Dp and Da values. As a result, the relationships among land use methods, fractal dimension and soil fertility have been discussed. The study conclusions include that (i) fractal dimension indicates not only characteristics of soil texture but also effects of natural environment changes and human activities on soil properties, (ii) soil fertility is best when Dp <2.65 and Da <2.44, (iii) maximal values of Dp under all land use patterns are equal and appear in the range the depth of 15-20 cm in the study area, but maximal values of Da are different and distribute in various profile depth. These results can provide an important support to understand soil properties in plateau soil-forming environment, and be helpful to conduct scientific soil tillage and management.

  2. Wind speed change regionalization in China(1961-2012)

    Institute of Scientific and Technical Information of China (English)

    SHI; Pei-Jun; ZHANG; Gang-Feng; KONG; Feng; YE; Qian

    2015-01-01

    This research quantitatively recognized the wind speed change using wind speed trend and trend of wind speed variability from 1961 to 2012 and regionalized the wind speed change on a county-level basis.The mean wind speed observation data and linear fitting method were used.The findings suggested that level-I regionalization includes six zones according to wind speed trend value in different regions,viz.Northeast ChinaeNorth China substantial declining zone,EasteCentral China declining zone,Southeast China slightly declining zone,Southwest China very slightly declining zone,Northwest China declining zone,and QinghaieTibetan Plateau slightly declining zone.Level-II regionalization divides China into twelve regions based on trend of wind speed variability and the level-I regionalization results.

  3. Intercropping competition between apple trees and crops in agroforestry systems on the Loess Plateau of China.

    Science.gov (United States)

    Gao, Lubo; Xu, Huasen; Bi, Huaxing; Xi, Weimin; Bao, Biao; Wang, Xiaoyan; Bi, Chao; Chang, Yifang

    2013-01-01

    Agroforestry has been widely practiced in the Loess Plateau region of China because of its prominent effects in reducing soil and water losses, improving land-use efficiency and increasing economic returns. However, the agroforestry practices may lead to competition between crops and trees for underground soil moisture and nutrients, and the trees on the canopy layer may also lead to shortage of light for crops. In order to minimize interspecific competition and maximize the benefits of tree-based intercropping systems, we studied photosynthesis, growth and yield of soybean (Glycine max L. Merr.) and peanut (Arachis hypogaea L.) by measuring photosynthetically active radiation, net photosynthetic rate, soil moisture and soil nutrients in a plantation of apple (Malus pumila M.) at a spacing of 4 m × 5 m on the Loess Plateau of China. The results showed that for both intercropping systems in the study region, soil moisture was the primary factor affecting the crop yields followed by light. Deficiency of the soil nutrients also had a significant impact on crop yields. Compared with soybean, peanut was more suitable for intercropping with apple trees to obtain economic benefits in the region. We concluded that apple-soybean and apple-peanut intercropping systems can be practical and beneficial in the region. However, the distance between crops and tree rows should be adjusted to minimize interspecies competition. Agronomic measures such as regular canopy pruning, root barriers, additional irrigation and fertilization also should be applied in the intercropping systems.

  4. Intercropping competition between apple trees and crops in agroforestry systems on the Loess Plateau of China.

    Directory of Open Access Journals (Sweden)

    Lubo Gao

    Full Text Available Agroforestry has been widely practiced in the Loess Plateau region of China because of its prominent effects in reducing soil and water losses, improving land-use efficiency and increasing economic returns. However, the agroforestry practices may lead to competition between crops and trees for underground soil moisture and nutrients, and the trees on the canopy layer may also lead to shortage of light for crops. In order to minimize interspecific competition and maximize the benefits of tree-based intercropping systems, we studied photosynthesis, growth and yield of soybean (Glycine max L. Merr. and peanut (Arachis hypogaea L. by measuring photosynthetically active radiation, net photosynthetic rate, soil moisture and soil nutrients in a plantation of apple (Malus pumila M. at a spacing of 4 m × 5 m on the Loess Plateau of China. The results showed that for both intercropping systems in the study region, soil moisture was the primary factor affecting the crop yields followed by light. Deficiency of the soil nutrients also had a significant impact on crop yields. Compared with soybean, peanut was more suitable for intercropping with apple trees to obtain economic benefits in the region. We concluded that apple-soybean and apple-peanut intercropping systems can be practical and beneficial in the region. However, the distance between crops and tree rows should be adjusted to minimize interspecies competition. Agronomic measures such as regular canopy pruning, root barriers, additional irrigation and fertilization also should be applied in the intercropping systems.

  5. 40 CFR 81.162 - Northeast Plateau Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Air Quality Control Regions § 81.162 Northeast Plateau Intrastate Air Quality Control Region. The Northeast Plateau Intrastate Air Quality Control Region (California) consists of the territorial area... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Northeast Plateau Intrastate...

  6. Lateral variation of Pn velocity beneath northeastern marginal region of Qinghai- Xizang plateau

    Institute of Scientific and Technical Information of China (English)

    许忠淮; 汪素云; 裴顺平

    2003-01-01

    Pn arrival time data are collected from the bulletins of both national and regional seismological network in China. These data are tomographically inverted to map the lateral variation and anisotropy of Pn velocity in the northeastern marginal region of Qinghai-Xizang plateau. The average Pn velocity in this region is 8.09 km/s, being a little higher than the average for whole China. Higher velocity is found in tectonically stable Qaidam basin, while lower velocity is seen in and around tectonically active Shanxi graben. The region where the 1920 Haiyuan great earthquake occurred shows a slightly low Pn velocity. A noticeable result is that, differing from the tectonically compressive Tianshan region, where Pn velocity is low, the Qilianshan region, where the Neotectonic deformation is also primarily compressive, shows high Pn velocity. In the uppermost mantle beneath the Ordos plateau Pn velocity is inhomogeneous, varying from higher velocity in southwestern part to lower one in northeastern part. This may be attributed to possible movement of the Ordos block, as there are strong earthquakes all around the block.

  7. Simulation for Artificial Forest Succession in Hilly-gully Area of Loess Plateau, China

    Science.gov (United States)

    Zhao, J., Jr.; Zhao, Z.; Yang, Y.

    2015-12-01

    The wide and large afforestation caused the great changes of surface albedo, water cycles, soil compositions and regional climate conditions on the Loess Plateau. There was increasing evidence showed that many problems had been occurred since ecological protection program began. Whether the artificial forest would adapt to environmental conditions on Loess Plateau is still controversial. In this paper, LANDIS-II, a spatially explicit model which included extension modules such as succession, disturbance, seed propagation, forest management, carbon dynamics and climate change, was applied to simulate dynamic natural succession of forests for coming 300 years in hilly-gully area of Loess Plateau. The results showed that (1) During the advancement of succession, the study area was occupied by different communities and appeared different succession stage successively under the condition of without considering the disturbance; (2) The current artificial forest has changed from 93.31% of Robinia pseudoacacia to exit the forest community in 50 years; (3) Platycladus oriental was the dominant species of coniferous trees and Populus davidiana was the dominant species of deciduous trees; (4)During the late succession stage, Platycladus oriental replaced Pinus tabulaeformis becoming the largest areal proportion of dominant tree species. The simulating of the natural succession in hilly-gully area of Loess Plateau forests at large space and long term scales, could provide a scientific basis for rational allocation of forest resources and forest management. In addition, our work clarifies the challenges and opportunities for the application of the model in the artificial forest and in hilly-gully area of Loess Plateau, China.

  8. Simulating the Effect of Climate Change on Vegetation Zone Distribution on the Loess Plateau, Northwest China

    Directory of Open Access Journals (Sweden)

    Guoqing Li

    2015-06-01

    Full Text Available A risk assessment of vegetation zone responses to climate change was conducted using the classical Holdridge life zone model on the Loess Plateau of Northwest China. The results show that there are currently ten vegetation zones occurring on the Loess Plateau (1950–2000, including alvar desert, alpine wet tundra, alpine rain tundra, boreal moist forest, boreal wet forest, cool temperate desert, cool temperate desert scrub, cool temperate steppe, cool temperate moist forest, warm temperate desert scrub, warm temperate thorn steppe, and warm temperate dry forest. Seventy years later (2070S, the alvar desert, the alpine wet tundra and the cool temperate desert will disappear, while warm temperate desert scrub and warm temperate thorn steppe will emerge. The area proportion of warm temperate dry forest will expand from 12.2% to 22.8%–37.2%, while that of cool temperate moist forest will decrease from 18.5% to 6.9%–9.5%. The area proportion of cool temperate steppe will decrease from 51.8% to 34.5%–51.6%. Our results suggest that future climate change will be conducive to the growth and expansion of forest zones on the Loess Plateau, which can provide valuable reference information for regional vegetation restoration planning and adaptive strategies in this region.

  9. Ecologically asynchronous agricultural practice erodes sustainability of the Loess Plateau of China.

    Science.gov (United States)

    Wang, Tianming; Wu, Jianguo; Kou, Xiaojun; Oliver, Chadwick; Mou, Pu; Ge, Jianping

    2010-06-01

    Sustainability of agricultural landscapes depends largely on land-use practices. As one of the most productive and widespread agricultural soils, loess is often deep and easily eroded, posing grand challenges for environmental sustainability around the world. One prime example is the Loess Plateau of China, which has been cultivated for more than 7500 years. Based on long-term data sets, this study demonstrates that the dominant agricultural practice, winter wheat cropping, continues to be the primary driver for the massive soil erosion and landscape modifications on the Loess Plateau. This traditional farming system is asynchronous with the dynamic rhythm between natural vegetation and climate in the region. In particular, the long summer fallow period for winter wheat fields is concurrent with the heavy-rainstorm season, which greatly accelerates soil erosion. Our finding indicates that common land-use practices that have lasted for thousands of years in China are not environmentally sustainable. Agriculture in this region has relied primarily on the continuous "mining" of the soil for the past several thousand years but does not have a one-thousand-year future because of myriad environmental and socioeconomic factors associated with soil erosion. To contain soil erosion and promote sustainability on the Loess Plateau, therefore, a change in the agricultural regime is needed to make sure that current and future agricultural practices follow the vegetation-climate rhythm. In addition, to achieve environmental, economic, and social sustainability in this region, multifunctional land-use planning is required to increase landscape diversity and functions (e.g., proper arrangement of crop fields, orchards, and protected areas).

  10. Development of highway constructing technology in the permafrost region on the Qinghai-Tibet plateau

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Qinghai-Tibet Highway passes through the Qinghai-Tibet plateau hinterland from north to south, from Kunlun Mountain to Tanggula Mountain. The average altitude is above 4500 m and permafrost covers more than 700 km length of area with high elevation and high temperature. The climate of the plateau is capricious and the surroundings along the road are bad, where the mean annual atmosphere temperature is -2 to -7℃ and the oxygen content is inadequate, which is less than 50% of the sea level, while the solar radiation is higher than 3600 kJ/m2. The basic characteristics of the plateau surroundings are the permafrost, coldness with litter oxygen, and fragile ecosystem. As the air temperature warms all over the world, the permafrost on the plateau responds quickly. The average temperature of permafrost is up by 0.2―0.3℃ in recent 20 years, and the island-permafrost dwindles with a high rate, and the high temperature permafrost degrades quickly, and the temperature of the low temperature permafrost increases remarkably. These gradually cause the highway engineering diseases in the permafrost region. The Qinghai-Tibet highway has experienced much maintenance and rebuilding for 50 years after it was built, and the continual observation and investigation have been made for more than 30 years. This road is the longest test engineering for permafrost research work in China. It is no doubt that it is also the greatest engineering project in plateau permafrost region. The Ministry of Communication in China initiated the research project "Research on a series of technologies for highway constructing in the permafrost regions" in 2002, which was to meet the challenges from the effect of climatic warming on the permafrost. The project systematically studied the permafrost engineering theories, methods for survey and design, engineering stabilization measures, preventing of the road disasters and maintaining, environment protection and the techniques to prolong the road

  11. Development of highway constructing technology in the permafrost region on the Qinshai-Tibet plateau

    Institute of Scientific and Technical Information of China (English)

    WANG ShuangJie; CHEN JianBing; ZHANG JinZhao; LI ZhuLong

    2009-01-01

    The Qinghai-Tibet Highway passes through the Qinghai-Tibet plateau hinterland from north to south, from Kunlun Mountain to Tanggula Mountain. The average altitude is above 4500 m and permafrost covers more than 700 km length of area with high elevation and high temperature. The climate of the plateau is capricious and the surroundings along the road are bad, where the mean annual atmosphere temperature is -2 to -7℃ and the oxygen content is inadequate, which is less than 50% of the sea level, while the solar radiation is higher than 3600 kJ/m2. The basic characteristics of the plateau surround-ings are the permafrost, coldness with litter oxygen, and fragile ecosystem. As the air temperature warms all over the world, the permafrost on the plateau responds quickly. The average temperature of permafrost is up by 0.2-0.3℃ in recent 20 years, and the island-permafrost dwindles with a high rate,and the high temperature permafrost degrades quickly, and the temperature of the low temperature permafrost increases remarkably. These gradually cause the highway engineering diseases in the permafrost region. The Qinghai-Tibet highway has experienced much maintenance and rebuilding for 50 years after it was built, and the continual observation and investigation have been made for more than 30 years. This road is the longest test engineering for permafrost research work in China. It is no doubt that it is also the greatest engineering project in plateau permafrost region. The Ministry of Communication in China initiated the research project "Research on a series of technologies for highway constructing in the permafrost regions" in 2002, which was to meet the challenges from the effect of climatic warming on the permafrost. The project systematically studied the permafrost engi- neering theories, methods for survey and design, engineering stabilization measures, preventing of the road disasters and maintaining, environment protection and the techniques to prolong the road

  12. Warming in Arctic intermediate and deep waters around Chukchi Plateau and its adjacent regions in 1999

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Jinping; GAO; Guoping

    2005-01-01

    Based on the data measured during Arctic scientific expedition of China in 1999, the characteristics of temperature and salinity distributions around the Chukchi Plateau and its adjacent regions have been studied. It was found that the intermediate water with temperature higher than 0.5℃ existed in all parts of a 640 km section with a maximum temperature of 0.85℃ indicating a strong signal of the warming in Arctic Intermediate Water in 1999. Two important phenomena are described in this paper. First, the temperature of warm water was horizontally nonuniform. In the area of Chukchi Plateau, the temperature was higher, the layer of warm water was thicker and the depth of the warm water core was shallower than those in the area of continental slope. The horizontal nonuniformity of the temperature distribution of warming water implies that the upward heat flux should also be nonuniform, thus exerting different effects on sea ice thickness, ice extent, and air-sea heat exchange. The mechanism to generate higher temperature in the plateau region was the bypassing of current around the plateau area caused by the special local topography, which restricted water exchange across the plateau and conserved heat in the water body. Second, the deep water down to 1400 m was also warming with a temperature increase of 0.2℃. The warming in deep water reflects the occurrence of complicated heat redistribution processes in the intermediate water, which altered the thermal structure in the upper 1400 m. The warming data embody the obvious impact of global climate change on the Arctic Ocean and further studies are wanted.

  13. The Changing Pattern of Glaciers During Last 40 Years in Tibetan Plateau, China

    Science.gov (United States)

    Liu, S.; Guo, W.; Xu, J.; Li, J.; Wei, J.; Yu, P.

    2010-12-01

    As indicated from the first inventory of glaciers based on topographical maps in the 1960s and early 1980s in Tibetan Plateau, there are 36793 glaciers with total area and ice volume of 49873 km2 and 4561 km3, respectively, about 79 %, 84% and 81% of the total number, area and volume of glaciers in China. Glaciers are one of key factors in seasonal, annual and decadal variabilities of discharges of the well known large river systems like Yangtze, Ganges and so on in the region. Understanding the changes of glaciers in Tibetan Plateau is of significance to understand the availability of water resources that originated from glacierized basins and their potential impact on social-economic development and environmental conservation in the watersheds of high population density. To track the changes of glaciers in Tibetan Plateau during the past decades, we have compiled the current inventory of glaciers over the Tibetan Plateau, which was based on ASTER (Advanced Spaceborne Thermal Emission and Reflection radiometer) and Landsat TM imageries mostly acquired during late summers of 2005-2008. A band ratio threshold method was applied to orthorectified images for extraction of glacier outlines which were then carefully verified and modified manually (here referred to as CGI2008). These vectorized boundaries of glaciers were then compared with that of the first glacier inventory digitized based on aerial photos and topographical maps during the late 1950s and 1970s (referred to as CGI 1960s). Results demonstrates that glaciers in Tibetan Plateau have retreated significantly during last four decades with total areal reduction amounting to 16.3% or 0.47%/a. Glacier retreat exhibited distinctive spatial patterns with less changes in the central Tibetan Plateau, where glaciers belong to continental type of cold glacial base and low mass turnover rates. Obvious retreat of glaciers happened within the surrounding high mountainous ranges like the north slope of Himalaya, Qilian

  14. Agriculture sustainability in a sensitive environment--a case analysis of Loess Plateau in China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Loess Plateau, an arid and semi-arid region in Northwest China, is well-known for its most serious soil erosion in terms of sediment yield each year. Soil erosion, which is intensified by agricultural activities, is the major factor influencing sustainable agriculture development in this region. It reduces productivity by removing nutrients and especially reducing water availability that is essential for crop production in the area. It also brings about off-site costs by demanding more efforts for maintenance of banks and dams along Yellow River through raising the riverbed with sediment. Climate is capricious and extreme weather conditions occur frequently, which impairs normal agricultural production with erosion and also decrease of water availability. Extensive way of farming still dominates on the Loess Plateau, which cannot produce satisfying economic results and needs to be improved or altered. Conventional agricultural production pattern needs to be reconsidered for husbandry has not been granted its due position. Agriculture is the backbone of economy. Poor agricultural production impedes economic development and vice versa, backward economy also influences the advancement of agriculture. Besides a large population, education status of farmers is another threshold that requires being resolved for a sustainable agriculture.Although conventional agriculture has been practiced there for more than 5000 years, now it cannot meet the demand for food and fiber by the increasing population and some of its farming practices are contributing to environmental degradation directly or indirectly and can sustain no longer. Agriculture on Loess Plateau needs to find its own way of sustainability. To work toward a sustainable agriculture, chances and challenges both indwell on Loess Plateau.

  15. China from a regional perspective

    DEFF Research Database (Denmark)

    Schmidt, Johannes Dragsbæk

    The paper explains the political economic background for China's insertion to the world system. It furthermore expands on a critical perspective on China's soft power strategy. It goes on to discuss China's foreign policy strategy towards Southeast Asia and China's rivalry with the US in the region....

  16. CHINA SEEKS REGIONAL ENERGY COOPERATION

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    China is seeking to diversify channels for energy cooperation as it faces mounting challenges from surging energy demand, geopolitical risks and price volatility. The endowment and distribution of China's resources does not match the current situation of China's economic development. Those are the opinions aired by officials and experts at an international expo recently held in West China's Xinjiang Uygur Autonomous Region.

  17. [Dynamic monitoring of ecological environment in loess hilly and gully region of Loess Plateau based on remote sensing: A case study on Fuxian County in Shaanxi Province. Northwest China].

    Science.gov (United States)

    Li, Fen-ling; Chang, Qin-rui; Shen, Jian; Liu, Jing

    2015-12-01

    Based on the principal component analysis (PCA), four ecological evaluation indicators including vegetation index, wet index, land surface temperature and soil index were combined to evaluate the ecological environment quality of Fuxian County in hilly and gully area of Loess Plateau from year 1995 to 2014. The results showed that the RSEI integrated RS and PCA method could reveal regional ecological changes objectively and quantitatively. The level of overall regional ecological status in Fuxian County was good with a high vegetation fraction and rich biodiversity. The synthetical ecological environment quality index increased from 3.17 to 3.53 indicating the ecological environment had been improved greatly in recent 20 years. The area with best ecological environment quality was located in Niuwu town. The magnitude of change increased progressively from northwest to southeast, and the biggest change occurred in Jiaodao and Nandaode towns. From 1995 to 2014, the areas with decreased and increased ecological environment quality were 16.7% and 42.7% of the study area, respectively, and the improved regions were mainly distributed in plateau and hilly area in the center, rocky low mountainous area in northeast and the Ziwuling Nature Reserve area in southwest of the county.

  18. Papillary thyroid carcinoma risk factors in the Yunnan plateau of southwestern China

    Directory of Open Access Journals (Sweden)

    Zeng R

    2016-06-01

    Full Text Available Rong Zeng,1–3 Tao Shou,3 Kun-xian Yang,4 Tao Shen,5 Jin-ping Zhang,5 Rong-xia Zuo,5 Yong-qing Zheng,5 Xin-ming Yan5 1Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, People’s Republic of China; 2Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, People’s Republic of China; 3Medical Oncology, The First People’s Hospital of Yunnan Province, Kunming, People’s Republic of China; 4Surgical Oncology, The First People’s Hospital of Yunnan Province Kunming, People’s Republic of China; 5Institute of Clinical and Basic Medicine Research, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, People’s Republic of China Objective: This study investigated clinical and pathological characteristics and risk factors in papillary thyroid carcinoma (PTC patients’ native to Yunnan plateau in southwestern China. Methods: Clinical data from 1,198 patients diagnosed with PTC (n=578 and control subjects (n=620 with benign thyroid disease (ie, thyroid nodule disease, benign thyroid diseases [BTD] in Yunnan province were analyzed retrospectively. Results: The mean patient age was lower for PTC than for BTD. Positive ratios of thyroid peroxidase antibody, thyroglobulin antibody (TGAb, and thyrotrophin receptor antibody (TRAb were higher in PTC than in BTD patients. The ratio of PTC coexisting with Hashimoto’s thyroiditis (HT or with lymphocytic thyroiditis was higher than that of BTD. The number of patients whose age at menarche was ≤13 years, who had given birth to less than or equal to two children, or who were in premenopause were higher in the PTC than in the BTD group. Multivariate conditional logistic regression analyses revealed that age >45 years, nodal size >1 cm, and elevated TG levels were protective factors against PTC. Abnormally elevated TGAb and TRAb levels were independent risk factors for PTC in females

  19. Changes in Ecosystem Service Values on the Loess Plateau in Northern Shaanxi Province, China

    Institute of Scientific and Technical Information of China (English)

    LI Jing; REN Zhi-yuan

    2008-01-01

    The Loess Plateau in northern Shaanxi Province of China covers Yulin, Yan'an, and Tongchuan cities mainly. The kind of physiognomy is complicated and various, including the transitional region of the sand and wind, the hilly-gully fragile region, the pimple mound region from North to South. Large-scale land reclamation projects that are severely affecting these ecosystems have been implemented. In this paper, we reported an investigation to the changes in land use and ecosystem services on the Loess Plateau in northern Shaanxi Province from 1978 to 2000. We used three LANDSAT TM and/or ETM data sets to estimate the changes in the size of five land-cover/land-use categories, and we also used previously published value coefficients to estimate the changes in the value of ecosystem services delivered by each land category. Finally, we ranked the contribution of various ecosystem functions to the overall value of the ecosystem services, we have estimated that the annual value of the ecosystem services is 56.95 billon RMB yuan in the Loess Plateau in northern Shaanxi Province in 2000. In the region, from 1978 to 2000, the economic value of the fixing carbon was higher,the economic value of water conservation was the lowest, but the economic value of the NPP, fixing carbon, and supplying oxygen accounted for above ninety percent of the total value, obviously the vegetation created the biggest ecosystem service value. We can conclude that future land-use policy formulation should give precedence to the conservation of these ecosystems over uncontrolled reclamation, and that further land reclamation should be based on rigorous environmental impact analyses.

  20. Advance in Application of Regional Climate Models in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; YAN Minhua; CHEN Panqin; XU Helan

    2008-01-01

    Regional climate models have become the powerful tools for simulating regional climate and its changeprocess and have been widely used in China. Using regional climate models, some research results have been obtainedon the following aspects: 1) the numerical simulation of East Asian monsoon climate, including exceptional monsoonprecipitation, summer precipitation distribution, East Asian circulation, multi-year climate average condition, summerrain belt and so on; 2) the simulation of arid climate of the western China, including thermal effect of the Qing-hai-Tibet Plateau, the plateau precipitation in the Qilian Mountains; and the impacts of greenhouse effects (CO2 dou-bling) upon climate in the western China; and 3) the simulation of the climate effect of underlying surface changes, in-cluding the effect of soil on climate formation, the influence of terrain on precipitation, the effect of regional soil deg-radation on regional climate, the effect of various underlying surfaces on regional climate, the effect of land-sea con-trast on the climate formulation, the influence of snow cover over the plateau regions on the regional climate, the effectof vegetation changes on the regional climate, etc. In the process of application of regional climate models, the prefer-ences of the models are improved so that better simulation results are gotten. At last, some suggestions are made aboutthe application of regional climate models in regional climate research in the future.

  1. Perfluorinated carboxylic and sulphonic acids in surface water media from the regions of Tibetan Plateau: Indirect evidence on photochemical degradation?

    Science.gov (United States)

    Yamazaki, Eriko; Falandysz, Jerzy; Taniyasu, Sachi; Hui, Ge; Jurkiewicz, Gabriela; Yamashita, Nobuyoshi; Yang, Yong-Liang; Lam, Paul K S

    2016-01-01

    Perfluorinated surfactants and repellents are synthetic substances that have found numerous industrial and customer applications. Due to their persistence, at least two groups of these substances-perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonic acids (PFSAs)-are diffused widely in the environment. It is hypothesized that the Tibetan Plateau, is one of few unique places on the Earth, due to its topography, specifically the vast space and high elevation above sea level, geographic location, climate, high solar radiation, lack of industry, little urbanization and general lack of significant direct sources of pollution. There it is believed possible to gain an insight into atmospheric fate (possible photochemical degradation of higher molecular mass and formation of lower molecular mass PFCAs and PFSAs) of PFASs under un-disturbed environmental conditions. Ultratrace analytical method for PFCAs and PFSAs and use of transportation and field blanks, laboratory blanks and isotopically labelled surrogates for recovery control has allowed the determination of nine perfluorinated carboxylic acids and six perfluorinated sulfonic acids at ultra-trace levels in water based samples from the alpine dimension regions of the Tibetan Plateau, the eastern slope of Minya Konka peak at the eastern edge of the Tibetan Plateau, and also from the city of Chengdu from the lowland of the Sichuan Province in China. The specific compositional pattern of PFCAs and PFSAs and low levels of pollution with those compounds were observed in the central region of the Tibetan Plateau and in the region adjacent to the peaks of Minya Konka in the Eastern Tibetan Plateau. The fingerprint of the compositional pattern of PFCAs and PFSAs in water samples in the central region of the Tibetan Plateau and in the alpine region adjacent to the peaks of Minya Konka in the Eastern Tibetan Plateau may be explained by the result of photochemical degradation with dealkylation of longer chain

  2. Autumn Daily Characteristics of Land Surface Heat and Water Exchange over the Loess Plateau Mesa in China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Loess Plateau, located in northern China, has a significant impact on the climate and ecosystem evolvement over the East Asian continent. In this paper, the preliminary autumn daily characteristics of land surface energy and water exchange over the Chinese Loess Plateau mesa region are evaluated by using data collected during the Loess Plateau land-atmosphere interaction pilot experiment (LOPEX04), which was conducted from 25 August to 12 September 2004 near Pingliang city, Gansu Province of China. The experiment was carried out in a region with a typical landscape of the Chinese Loess Plateau, known as "loess mesa". The experiment's field land utilizations were cornfield and fallow farmland, with the fallow field later used for rotating winter wheat. The autumn daily characteristics of heat and water exchange evidently differed between the mesa cornfield and fallow, and the imbalance term of the surface energy was large. This is discussed in terms of sampling errors in the flux observations footprint; energy storage terms of soil and vegetation layers; contribution from air advections; and low and high frequency loss of turbulent fluxes and instruments bias. Comparison of energy components between the mesa cornfield and the lowland cornfield did not reveal any obvious difference. Inadequacies of the field observation equipment and experimental design emerged during the study, and some new research topics have emerged from this pilot experiment for future investigation.

  3. 'Roof of the World' Tibetan Plateau of China as seen from STS-67

    Science.gov (United States)

    1995-01-01

    Two major physiographic features are very much in evidence in this photograph. First, a small segment of the very rugged Himalayan Mountains is observed in the foreground. This virtually cloud-free color photograph (general direction of view is northerly) shows part of the snow-covered northwest by southeast trending Himalayas. Several glaciers radiate to the north from the northernmost regions of the Himalayas. A fairly extensive, largely snow-covered intermontane valley is also evident across the center section of the photograph. The Gangdise Mountains, another northwest by southeast trending range, forms the northern boundary of the broad valley. Several major ice and snow-covered identifiable lakes are seen on the Tibetan Plateau of China. This photograph show why this region is called the 'Roof of the World'.

  4. The system of physico-geographical regions of the Qinghai-Xizang (Tibet) Plateau

    Institute of Scientific and Technical Information of China (English)

    郑度

    1996-01-01

    The Qinghai-Xizang Plateau is a unique physico-geographical region on the earth. As a whole, the spatial differentiation of physico-geographical regions of the plateau is mainly determined by topographic configuration and atmospheric circulation, warm and humid in the southeast, cold and arid in the northwest. The natural landscapes apppear in the following succession: forest → meadow → steppe → desert. The system of physico-geographical regions of the plateau is demarcated on the principle of bio-climate or the principle of three dimension zonality. Based on the thermal conditions, moisture regimes and variation in landform the Qinghai-Xizang Plateau is sequentially demarcated. The duration of mean daily temperature above 10℃ is the principal index, the subsidiary criterion is mean temperature of the warmest month, two temperature belts may be divided: plateau subpolar and plateau temperate. Annual aridity is taken as the principal index, subordinated by annual precipitation. Four moisture regional

  5. Molecular analysis of cultivated naked barley (Hordeum vulgare L.) from Qinghai-Tibet Plateau in China using SSR markers

    Institute of Scientific and Technical Information of China (English)

    Zhifen PAN; Guangbing DENG; Xuguang ZHAI; Hai LONG; Yawei TANG; Xiaolin QIANG; Maoqun YU

    2008-01-01

    Naked barley is widely planted in Qinghai-Tibet Plateau in China and is essential for the daily life of Tibetans in those regions. In this study, the genetic diversity of 64 cultivated naked barley accessions from Qinghai-Tibet Plateau in China was analyzed using 30 mapped SSRs linked with the important traits of barley improvement. A total of 132 alleles were identified at 22 polymorphic SSR loci, with the number of each locus ranging from 2 to 15, the polymorphism information con-tent (PIC) values ranging from 0.16 to 0.91, and with an average of 0.65. Of the selected SSRs, 13 SSR markers with high PIC value were highly efficient for the genetic analysis of Chinese barley. The accessions were divided into five main groups by cluster analysis and could be differentiated from each other. The genetic diversity in the Tibet accessions was slightly higher than in the Sichuan accessions. It is found that there were specific genes linked with the collecting sites. These results indi-cate the cultivated naked barley from Qinghai-Tibet Plateau in China are highly polymorphic and could be considered as an important resource bank for cultivated naked barley breeding in the future.

  6. Effects of different vegetation restoration models on soil microbial biomass in eroded hilly Loess Plateau, China

    Institute of Scientific and Technical Information of China (English)

    XUE Sha; LIU Guobin; DAI Quanhou; LAN Xue; YU Na

    2007-01-01

    Vegetation restoration is a key measure to improve the eco-environment in Loess Plateau,China.In order to find the effect of soil microbial biomass under different vegetation restoration models in this region,six trial sites located in Zhifanggou watershed were selected in this study.Results showed that soil microbial biomass,microbial respiration and physical and chemical properties increased apparently.After 30 years of vegetation restoration,soil microbial biomass C,N,P(SMBC,SMBN,SMBP)and microbial respiration,increased by 109.01%-144.22%,34.17%-117.09%,31.79%-79.94% and 26.78%-87.59% respectively,as compared with the farmland.However,metabolic quotient declined dramatically by 57.45%-77.49%.Effects of different models of vegetation restoration are different on improving the properties of soil.In general,mixed stands of Pinus tabulaeformisAmorpha fruticosa and Robinia pseudoacacia-A,fruticosa had the most remarkable effect,followed by R.pseudoacacia and Caragana korshinkii,fallow land and P.tabulaeformis was the lowest.Restoration of mixed forest had greater effective than pure forest in eroded Hilly Loess Plateau.The significant relationships were observed among SMBC,SMBP,microbial respiration,and physical and chemical properties of soil.It was concluded that microbial biomass can be used as indicators of soil quality.

  7. Papillary thyroid carcinoma risk factors in the Yunnan plateau of southwestern China

    Science.gov (United States)

    Zeng, Rong; Shou, Tao; Yang, Kun-xian; Shen, Tao; Zhang, Jin-ping; Zuo, Rong-xia; Zheng, Yong-qing; Yan, Xin-ming

    2016-01-01

    Objective This study investigated clinical and pathological characteristics and risk factors in papillary thyroid carcinoma (PTC) patients’ native to Yunnan plateau in southwestern China. Methods Clinical data from 1,198 patients diagnosed with PTC (n=578) and control subjects (n=620) with benign thyroid disease (ie, thyroid nodule disease, benign thyroid diseases [BTD]) in Yunnan province were analyzed retrospectively. Results The mean patient age was lower for PTC than for BTD. Positive ratios of thyroid peroxidase antibody, thyroglobulin antibody (TGAb), and thyrotrophin receptor antibody (TRAb) were higher in PTC than in BTD patients. The ratio of PTC coexisting with Hashimoto’s thyroiditis (HT) or with lymphocytic thyroiditis was higher than that of BTD. The number of patients whose age at menarche was ≤13 years, who had given birth to less than or equal to two children, or who were in premenopause were higher in the PTC than in the BTD group. Multivariate conditional logistic regression analyses revealed that age >45 years, nodal size >1 cm, and elevated TG levels were protective factors against PTC. Abnormally elevated TGAb and TRAb levels were independent risk factors for PTC in females. Conclusion HT was not an independent risk factor for but was associated with PTC. TRAb is a risk factor for PTC in individuals living in the Yunnan plateau, but not for those in the plains region. PMID:27418831

  8. Correlating check dam sedimentation and rainstorm characteristics on the Loess Plateau, China

    Science.gov (United States)

    Li, Xungui; Wei, Xia; Wei, Ning

    2016-07-01

    On the Loess Plateau, China, check dams are necessary for soil and water conservation. In this study, the relationships between check dam sedimentation and storm characteristics were investigated, and rainstorm events for an area of data scarcity were reconstructed using optimal regression models. Four typical check dams of the Loess Plateau (the Shipanmao, Hualiang, No. 3 Guandigou, and No. 4 Guandigou dams) were selected for case studies. Soil profiles behind the four dams were divided into 21, 25, 31, and 31 layers, respectively. The one-to-one link between sediment layers and corresponding storm characteristics were considered based on the peak fallout of 137Cs and on the principle that higher flow corresponds to higher sediment deposition volume. Analysis showed that the layered sediment volume (V) was closely related to rainfall erosivity (R), and to the maximum rainfall intensity over 30 min (I30). A statistically significant power regression model between V and R was observed, along with an exponential regression model between V and I30. Based on the power regression model between V and R, a new approach was developed in order to reconstruct rainfall erosivity in rainfall data-scarcity areas. Different hysteresis patterns (counterclockwise, clockwise, and hybrid) at the single storm scale were observed between V and R for the Shipanmao dam deposition wedge (depositional area behind a dam), and these impacted differently on the scale reconstruction results. However, the distance between the reconstructed dams and the known dams had an even stronger influence. The scale method developed in this study was shown to perform well and was able to reconstruct rainstorm events for adjacent regions with similar climatic and geomorphological conditions. Furthermore, the results of this study have improved our understanding of single rainstorm dynamics and soil erosion mechanisms on the Loess Plateau.

  9. Breaking the spiral of unsustainability : an exploratory land use study for Ansai, the Loess Plateau of China

    NARCIS (Netherlands)

    Lu, C.

    2000-01-01

    Serious soil loss, food insecurity, population pressure, and low income of the rural population are interrelated, and consequently result in a spiral of unsustainability in the Loess Plateau, China. This thesis takes Ansai County in the Loess Plateau of China as a case study, to explore str

  10. Breaking the spiral of unsustainability : An exploratory Land use study for Ansai, the Loess Plateau of China

    NARCIS (Netherlands)

    Lu Changhe,

    2000-01-01

    Serious soil loss, food insecurity, population pressure, and low income of the rural population are interrelated, and consequently result in a spiral of unsustainability in the Loess Plateau, China. This thesis takes Ansai County in the Loess Plateau of China as a case study, to explore strategic la

  11. Bartonella Species Detected in the Plateau Pikas (Ochotona curzoiae) from Qinghai Plateau in China.

    Science.gov (United States)

    Rao, Hua Xiang; Yu, Juan; Guo, Peng; Ma, Yong Cheng; Liu, Qi Yong; Jiao, Ming; Ma, Zhong Wen; Ge, Hua; Wang, Chun Xiang; Song, Xiu Ping; Shi, Yan; Li, Dong Mei

    2015-09-01

    Bartonella species can infect a variety of mammalian hosts and cause a broad spectrum of diseases in humans, but there have been no reports of Bartonella infection in Ochotonidae. This is the first study to detect Bartonella in plateau pikas in the Qinghai plateau, providing baseline data for the risk assessment of human Bartonella infection in this area. We obtained 15 Bartonella strains from 79 pikas in Binggou and Maixiu areas of Qinghai with a positive rate of 18.99%. Based on the phylogenetic analysis of the Bartonella citrate synthase (gltA) gene sequences, most strains were closely related to B. taylorii (3/15) and B. grahamii (12/15). The latter is a pathogenic strain in humans. Our results suggest that a corresponding prevention and control strategy should be taken into consideration in the Qinghai province.

  12. Assessing the hydrological effect of the check dams in the Loess Plateau, China, by model simulations

    Science.gov (United States)

    Xu, Y. D.; Fu, B. J.; He, C. S.

    2013-06-01

    Check dams are commonly used for soil conservation. In the Loess Plateau of China, check dams have been widely constructed as the principal means to retain floodwater and intercept soil sediments since the 1970s. For instance, there are more than 6572 check dams in the Yanhe watershed with an area of 7725 km2 in the Loess Plateau. However, little research has been done to quantify the hydrological effects of the check dams. In this research, the SWAT model (Soil and Water Assessment Tool) was applied to simulate the runoff and sediment in the Yanhe watershed. We treated the 1950s to 1960s as the reference period since there were very few check dams during the period. The model was firstly calibrated and validated in the reference period. The calibrated model was then used in the later periods to simulate the hydrological effects of the check dams. The results showed that the check dams had a regulation effect on runoff and a retention effect on sediment. From 1984 to 1987, the runoff in rainy season (from May to October) decreased by 1.54 m3 s-1 (14.7%) to 3.13 m3 s-1 (25.9%) due to the check dams; while in dry season (from November to the following April), runoff increased by 1.46 m3 s-1 (60.5%) to 1.95 m3 s-1 (101.2%); the sediment in rainy season decreased by 2.49 × 106 ton (34.6%) to 4.35 × 106 ton (48.0%). From 2006 to 2008, the runoff in rainy season decreased by 0.79 m3 s-1 (15.5%) to 1.75 m3 s-1 (28.9%), and the runoff in dry season increased by 0.51 m3 s-1 (20.1%) to 0.97 m3 s-1 (46.4%); the sediment in rainy season decreased by 2.03 × 106 ton (79.4%) to 3.12 × 106 ton (85.5%). Construction of the large number of check dams in the Loess Plateau has enhanced the region's capacity to control the runoff and sediment. In the Yanhe watershed, the annual runoff was reduced by less than 14.3% due to the check dams; and the sediment in rainy season was blocked by up to 85.5%. Thus, check dams are effective measures for soil erosion control in the Loess Plateau.

  13. Black carbon aerosol characterization in a remote area of Qinghai-Tibetan Plateau, western China.

    Science.gov (United States)

    Wang, Qiyuan; Schwarz, J P; Cao, Junji; Gao, Rushan; Fahey, D W; Hu, Tafeng; Huang, R-J; Han, Yongming; Shen, Zhenxing

    2014-05-01

    The concentrations, size distributions, and mixing states of refractory black carbon (rBC) aerosols were measured with a ground-based Single Particle Soot Photometer (SP2), and aerosol absorption was measured with an Aethalometer at Qinghai Lake (QHL), a rural area in the Northeastern Tibetan Plateau of China in October 2011. The area was not pristine, with an average rBC mass concentration of 0.36 μg STP-m(-3) during the two-week campaign period. The rBC concentration peaked at night and reached the minimal in the afternoon. This diurnal cycle of concentration is negatively correlated with the mixed layer depth and ventilation. When air masses from the west of QHL were sampled in late afternoon to early evening, the average rBC concentration of 0.21 μg STP-m(-3) was observed, representing the rBC level in a larger Tibetan Plateau region because of the highest mixed layer depth. A lognormal primary mode with mass median diameter (MMD) of ~175 nm, and a small secondary lognormal mode with MMD of 470-500 nm of rBC were observed. Relative reduction in the secondary mode during a snow event supports recent work that suggested size dependent removal of rBC by precipitation. About 50% of the observed rBC cores were identified as thickly coated by non-BC material. A comparison of the Aethalometer and SP2 measurements suggests that non-BC species significantly affect the Aethalometer measurements in this region. A scaling factor for the Aethalometer data at a wavelength of 880 nm is therefore calculated based on the measurements, which may be used to correct other Aethalometer datasets collected in this region for a more accurate estimate of the rBC loading. The results present here significantly improve our understanding of the characteristics of rBC aerosol in the less studied Tibetan Plateau region and further highlight the size dependent removal of BC via precipitation.

  14. Mechanism of crustal deformation in the Sichuan-Yunnan region, southeastern Tibetan Plateau: Insights from numerical modeling

    Science.gov (United States)

    Li, Yujiang; Liu, Shaofeng; Chen, Lianwang; Du, Yi; Li, Hong; Liu, Dongying

    2017-09-01

    The characteristics of crustal deformation and its dynamical mechanisms in the Sichuan-Yunnan region are of interest to many researchers because they can help explain the deformation pattern of the eastern Tibetan Plateau. In this paper, we employ a precise three-dimensional viscoelastic finite element model to simulate the crustal deformation in the Sichuan-Yunnan region, southeastern Tibetan Plateau. We investigate the influence of lower crustal flow and rheological variations by comparing the modeled results with GPS observations. The results demonstrate that lower crustal flow plays an important role in crustal deformation in the Sichuan-Yunnan region. The best fitting is achieved when the flow velocity of the lower crust is approximately 10-11 mm/a faster than that of the upper crust. Additionally, crustal rheological properties affect regional crustal deformation. When the viscosity of the middle and lower crust in the South China block reaches 1022 and 1023 Pa·s, respectively, the modeled results match observations well, especially for the magnitude of crustal motion within the South China block. Finally, our dynamic model shows that the maximum principal stress field of the Sichuan-Yunnan region exhibits clear zoning, gradually shifting from an approximately east-west orientation in the northern Bayan Har block to southeast in the South China block, southwest in the western Yunnan block, and a radially divergent distribution in the Middle Yunnan and Southern Yunnan blocks.

  15. The role of climatic and anthropogenic stresses on long-term runoff reduction from the Loess Plateau, China.

    Science.gov (United States)

    Feng, Xiaoming; Cheng, Wei; Fu, Bojie; Lü, Yihe

    2016-11-15

    Human intervention has strongly altered patterns of river runoff. Yet, few studies have addressed the complexity and nonlinearity of the anthropogenic stresses on runoff or their interaction with climate. We study the Loess Plateau in China, whose river runoff contributes 65% of the discharge to the middle reach of the Yellow River; this landscape has been shaped by human activity and is intensively managed. Our purpose is to characterize the interactive roles of climate and human activities in defining river runoff from the Loess Plateau. Applying a transient analysis to discover the time-varying runoff trend and impact factors, we found that the average runoff in the Loess Plateau decreased continuously during the period 1961-2009 (average rate of -0.9mmyear(-1), Prunoff mainly occurred in three stages, with transitions in 1970, 1981 and 1996. Reduced precipitation was the main reason for the decrease in runoff over the entire study period. However, human intervention played a dominant role in creating the transition points. Water yield (i.e., the ratio of runoff to precipitation) decreased following each anthropogenic transition, causing a 56% reduction in available freshwater resources during the period 1961-2009. These findings highlight the need for studies that address the dynamic and nonlinear processes controlling the availability of freshwater resources in the light of anthropogenic influences applied under a changing climate. Such studies are essential if we are to meet the human water demand in the Loess Plateau region.

  16. Porphyry copper assessment of the Tibetan Plateau, China: Chapter F in Global mineral resource assessment

    Science.gov (United States)

    Ludington, Steve; Hammarstrom, Jane M.; Robinson,, Gilpin R.; Mars, John L.; Miller, Robert J.

    2012-01-01

    The U.S. Geological Survey collaborated with the China Geological Survey to conduct a mineral-resource assessment of resources in porphyry copper deposits on the Tibetan Plateau in western China. This area hosts several very large porphyry deposits, exemplified by the Yulong and Qulong deposits, each containing at least 7,000,000 metric tons (t) of copper. However, large parts of the area are underexplored and are likely to contain undiscovered porphyry copper deposits.

  17. Cyclic precipitation variation on the western Loess Plateau of China during the past four centuries

    Science.gov (United States)

    Tan, Liangcheng; An, Zhisheng; Huh, Chih-An; Cai, Yanjun; Shen, Chuan-Chou; Shiau, Liang-Jian; Yan, Libin; Cheng, Hai; Edwards, R. Lawrence

    2014-09-01

    Precipitation variation on the Loess Plateau (LP) of China is not only important for rain-fed agriculture in this environmentally sensitive region, but also critical for the water and life securities over the whole Yellow River basin. Here we reconstruct high resolution precipitation variation on the western LP during the past 370 years by using two replicated, annually-laminated stalagmites. Spatial analysis suggests that the reconstruction can be also representative for the whole LP region. The precipitation variations show a significant quasi-50 year periodicity during the last 370 years, and have an important role in determining the runoff of the middle Yellow River. The main factor controlling the decadal scale variations and long-term trend in precipitation over this region is southerly water vapour transport associated with the Asian summer monsoon. The Pacific Decadal Oscillation is also an important influence on precipitation variation in this region, as it can affect the East Asian summer monsoon and the West Pacific Subtropical High.

  18. A trade-off analysis of policy objectives for Ansai, the Loess Plateau of China

    NARCIS (Netherlands)

    Lu, C.H.; Ittersum, van M.K.

    2004-01-01

    Ansai is a county characterized by hilly loess relief that experiences all problems typical to the Loess Plateau of northern China, such as population pressure, soil loss, over-use of marginal lands, and poverty and food insecurity problems. Alleviation of these problems needs an integrated consider

  19. Discharge and sediment measurements at the outlet of a watershed on the Loess plateau of China

    NARCIS (Netherlands)

    Elsen, van den H.G.M.; Hessel, R.; Liu Baoyuan,; Trouwborst, K.O.; Stolte, J.; Ritsema, C.J.; Blijenberg, H.

    2003-01-01

    A dam and weir system was constructed to measure the discharge of water and sediment from a selected small catchment on the Loess plateau in China. The aim of the system described here was to collect data on discharge and sediment content during occasional summer storms. These data can be used for c

  20. Effects of climatic gradients on genetic differentiation of Caragana on the Ordos Plateau, China

    Science.gov (United States)

    Jiuyan Yang; Samuel A. Cushman; Jie Yang; Mingbo Yang; Tiejun Bao

    2013-01-01

    The genus Caragana (Fabr.) in the Ordos Plateau of Inner Mongolia, China, provides a strong opportunity to investigate patterns of genetic differentiation along steep climatic gradients, and to identify the environmental factors most likely to be responsible for driving the radiation. This study used a factorial, multi-model approach to evaluate alternative hypotheses...

  1. New magnetochronology of Late Miocene mammal fauna, NE Tibetan Plateau, China : Mammal migration and paleoenvironments

    NARCIS (Netherlands)

    Ao, Hong; Zhang, Peng; Dekkers, Mark J.; Roberts, Andrew P.; An, Zhisheng; Li, Yongxiang; Lu, Fengyan; Lin, Shan; Li, Xingwen

    2016-01-01

    Lanzhou Basin lies on the northeastern margin of the Tibetan Plateau in western China and is a rich source of Oligocene-Miocene mammalian fossils. Obtaining precise age determinations for these fossils is important to address key questions concerning mammalian and environmental evolution in Asia

  2. China's Regional Autonomy

    Institute of Scientific and Technical Information of China (English)

    Wu Shimin

    2005-01-01

    @@ China is a vast country with a long history and splendid culture. One reason for this is that the Chinese nation consists of many ethnic groups. They have lived, procreated, struggled and made creative achievements on this land for several thousand years. China is a big family consisting of 56 ethnic groups. While the Han ethnic group has the largest population, the population of the other 55 ethnic groups is relatively small, so they are customarily referred to as "ethnic minorities."

  3. How ecological restoration alters ecosystem services: an analysis of carbon sequestration in China's Loess Plateau.

    Science.gov (United States)

    Feng, Xiaoming; Fu, Bojie; Lu, Nan; Zeng, Yuan; Wu, Bingfang

    2013-10-03

    Restoring disturbed and over-exploited ecosystems is important to mitigate human pressures on natural ecosystems. China has launched an ambitious national ecosystem restoration program called Grain to Green Program (GTGP) over the last decade. By using remote sensing techniques and ecosystem modelling, we quantitatively evaluated the changes in ecosystem carbon sequestration since China's GTGP program during period of 2000-2008. It was found the NPP and NEP in this region had steadily increased after the initiative of the GTGP program, and a total of 96.1 Tg of additional carbon had been sequestered during that period. Changes in soil carbon storage were lagged behind and thus insignificant over the period, but was expected to follow in the coming decades. As a result, the Loess Plateau ecosystem had shifted from a net carbon source in 2000 to a net carbon sink in 2008. The carbon sequestration efficiency was constrained by precipitation, and appropriate choices of restoration types (trees, shrubs, and grasses) in accordance to local climate are critical for achieving the best benefit/cost efficiency.

  4. Water and Energy Conservation of Rainwater Harvesting System in the Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhi-yun; LI Xiao-yan; MA Yu-jun

    2013-01-01

    Water is the source of all the creatures on the earth and energy is the main factor driving the world. With the increasing population and global change, water and energy conservation have become worldwide focal issues, particularly in the water-stressed and energy-limited regions. Rainwater harvesting, based on the collection and storage of rainfall runoff, has been widely used for domestic use and agricultural production in arid and semiarid regions. It has advantages of simple operation, high adaption, low cost and less energy consumption. This study reviewed rainwater harvesting systems adopted in the Loess Plateau of China and analyzed water use efficiency (WUE) for various rainwater harvesting techniques. Supplemental irrigation using harvested rainwater could increase crop yield by more than 30%, and WUE ranged from 0.7 to 5.7 kg m-3 for spring wheat, corn and flax, and 30-40 kg m-3 for vegetables. Moreover, energy consumption for rainwater harvesting based on single family was compared with traditional water supply in the city of the Loess Plateau using the life cycle assessment (LCA) method. Results showed that energy consumption yielded per unit harvested rainwater was 25.96 MJ m-3 yr-1 which was much less than 62.25 MJ m-3 yr-1 for main water supply in Baoji City, Shanxi Province, meaning that rainwater harvesting saved energy by 139.8%as compared to the main water supply system. This study highlights the importance and potential of rainwater harvesting for water and energy conservation in the near future.

  5. ON THE RELATIONSHIPS BETWEEN THE SUMMER RAINFALL IN CHINA AND THE ATMOSPHERIC HEAT SOURCES OVER THE EASTERN TIBETAN PLATEAU AND THE WESTERN PACIFIC WARM POOL

    Institute of Scientific and Technical Information of China (English)

    简茂球; 罗会邦; 乔云亭

    2004-01-01

    The relationships between the summer rainfall in China and the atmospheric heat sources over the eastern Tibetan Plateau and the western Pacific warm pool were analyzed comparatively, using the NCEP/NCAR reanalysis daily data. The strong (weak) heat source in summer over the eastern Tibetan Plateau will lead to abundant (scarce) summer rainfall in the Yangtze River basin, and scarce/abundant summer rainfall in the eastern part of Southern China. While the strong (weak) heat source in summer over the western Pacific warm pool will lead to another pattern of abundant (scarce) summer rainfall in the middle-lower reaches of the Yangtze River and scarce (abundant) summer rainfall in Southern China and in the region of northern Jiangsu to southern Shandong. Comparatively, the heat source over the eastern Tibetan Plateau affects a larger area of summer rainfall than the heat source over the western Pacific. In both cases of the heat source anomalies over the eastern Tibetan Plateau and over the western Pacific, there exist EAP-like teleconnection patterns in East Asia. The summer rainfall in China is influenced directly by the abnormal vertical motion, which is related closely to the abnormal heat sources in the atmosphere. The ridge line of the western Pacific High locates far south (north) in summer in the case of strong (weak) heat sources over the two areas mentioned above.

  6. Hydrologic feasibility of artificial forestation in the semi-arid Loess Plateau of China

    Directory of Open Access Journals (Sweden)

    T. T. Jin

    2011-08-01

    Full Text Available Hydrologic viability, in terms of moisture availability, is fundamental to ecosystem sustainability in arid and semi-arid regions. In this study, we examine the spatial distribution and after-planting variations of soil moisture content (SMC in black locust tree (Robinia pseudoacacia L. plantings in the Loess Plateau of China at a regional scale. Thirty sites (5 to 45 yr old were selected, spanning an area of 300 km by 190 km in the northern region of the Shaanxi Province. The SMC was measured to a depth of 100 cm at intervals of 10 cm. Geographical, topographic and vegetation information was recorded, and soil organic matter was evaluated. The results show that, at the regional scale, SMC spatial variability was most highly correlated with rainfall. The negative relationship between the SMC at a depth of 20–50 cm and the stand age was stronger than at other depths, although this relationship was not significant at a 5 % level. Watershed analysis shows that the after-planting SMC variation differed depending upon precipitation. The SMC of plantings in areas receiving sufficient precipitation (e.g., mean annual precipitation (MAP of 617 mm may increase with stand age due to improvements in soil water-holding capacity and water-retention abilities after planting. For areas experiencing water shortages (e.g., MAP = 509 mm, evapotranspiration may cause planting soils to dry within the first 20 yr of growth. It is expected that, as arid and semi-arid plantings age, evapotranspiration will decrease, and the soil profile may gradually recover. In extremely dry areas (e.g., MAP = 352 mm, the variation in after-planting SMC with stand age was found to be negligible. The MAP can be used as an index to divide the study area into different ecological regions. Afforestation may sequentially exert positive, negative and negligible effects on SMCs with a decrease in the MAP. Therefore, future restoration measures should correspond to the local climate

  7. New transhumance in the Mahafaly Plateau region in Madagascar

    African Journals Online (AJOL)

    models influence people's capacity to adapt, especially in socio- .... pastoral mobility have mainly been described as climate change adaptation strategies ..... transhumance on the plateau, where most herders can build on a ..... and ecosystem services in southern Madagascar. .... Migration as a contribution to resilience.

  8. On Financial System Development of China's Tibetan Region

    Institute of Scientific and Technical Information of China (English)

    JIANG Xia

    2014-01-01

    China's Tibetan Region, located in the highest plateau , includes the Tibetan Auton-omous Region , ten Tibetan autonomous prefec-tures, and two Tibetan autonomous counties in Qinhai , Sichuan , Yunnan and Gansu .The region is economically backward and has substantially re-lied on central Chinese government's fiscal transfer payments and aid from other provinces in China . As a result, the financial sector in the region is un-derdeveloped and is not able to play an active role in supporting the region's leaping economic devel-opment .It is necessary to analyze the current fi-nancial system in the Tibetan region , to find out where the problems lie and how to modify the fi-nancial system .

  9. Identifying the source regions of persistent organic pollutants (POPs) in the southern Tibetan Plateau

    Science.gov (United States)

    Gong, P.; Wang, X.; Yao, T.

    2016-12-01

    A worldwide attention focus on the semi-volatilities and long-range atmospheric transport potential of persistent organic pollutants (POPs). Even in the remote regions with less anthropological activities (such as Arctic, Antarctic), POPs are often detected in air and finally are trapped by the surface ground, which made those regions as a "sink" of POPs. The Tibetan Plateau is also a remote region, and it is adjacent to South Asia with huge emission of POPs. The strong monsoon favors to the atmospheric transport of pollutants from South Asia to the Tibetan Plateau. Unlike Arctic and Antarctic, the Tibetan Plateau can become a "secondary source" for some POPs and make them spread globally. By now, some efforts were conducted to report that South Asia is one of the primary source region of POPs in the Tibetan Plateau. In this study, the detailed source regions were identified using 1-year observed atmospheric POPs data in three sites distributing the southern Tibetan Plateau (Lhasa, Lulang, and Lijiang). The highest concentrations of atmospheric POPs in the three sites all occurred in the Monsoon season (June-September), implying that the Indian monsoon may be the driving force of POPs transport to the southern Tibetan Plateau. The relative components of POPs in these sites are similar with those in India, which suggest that South Asia (especially India) might be the main source regions. The results of potential source contribution function (PSCF) further identified that the offshore of Bengal Bay is the most probable emission source region of the POPs invading into the Tibetan Plateau. The mega-cities, such as Kolkata, Bhubaneswar, Chennai, Dhaka, Chittagong, around the Bengal Bay supplied the major contribution of the POPs which transported to the Tibetan Plateau.

  10. Extensional Seismogenic Stress and Tectonic Movement on the Central Region of the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Jiren Xu

    2009-01-01

    Full Text Available Various earthquake fault types, mechanism solutions and stress fields, as well as GPS and geothermal data are analyzed for the study of the crustal movements on the Tibetan plateau and their tectonic implications. The results show that a lot of the normal faulting type-event concentrated at altitudes greater than 4000 m on the central Tibetan plateau. The altitudes concentrating normal faulting type-events can be zoned two parts: the western part, the Lhasa block, and the eastern part, the Qiangtang-Changdu region. The azimuths of T-axes are in a general E-W direction in the Lhasa block and NW-SE or NNW-SSE in the Qiangtang-Changdu region at the altitudes of the Tibetan plateau. The tensional stresses in E-W direction and NW-SE direction predominate normal faulting earthquake occurrence in the Lhasa block and the Qiangtang-Changdu region, respectively. The slipping displacements of the normal-faulting-type events have great components in near E-W direction and NW-SE direction in the Lhasa block and the Qiangtang-Changdu region, respectively. The extensions are probably an eastward or southeastward extensional motion, being mainly tectonic activity phenomena in the plateau altitudes. The extensional motions due to normal-fault earthquakes are important tectonic activity regimes on the high altitudes of the plateau. The easterly crustal extensions on the plateau are attributable to the gravitational collapse of the high plateau and eastward extrusion of hotter mantle materials beneath the eastern boundary of the plateau. Numbers of thrust-fault and strike-slip-fault earthquakes with strong compressive stress in a general NNE-SSW direction occur on the edges of the plateau.

  11. Possible association of the western Tibetan Plateau snow cover with the decadal to interdecadal variations of northern China heatwave frequency

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhiwei [Nanjing University of Information Science and Technology, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing (China); Chinese Academy of Sciences, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Beijing (China); Jiang, Zhihong; Zhong, Shanshan; Wang, Lijuan [Nanjing University of Information Science and Technology, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing (China); Li, Jianping [Chinese Academy of Sciences, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Beijing (China)

    2012-11-15

    Northern China has been subject to increased heatwave frequency (HWF) in recent decades, which deteriorates the local droughts and desertification. More than half a billion people face drinking water shortages and worsening ecological environment. In this study, the variability in the western Tibetan Plateau snow cover (TPSC) is observed to have an intimate linkage with the first empirical orthogonal function mode of the summer HWF across China. This distinct leading mode is dominated by the decadal to inter-decadal variability and features a mono-sign pattern with the extreme value center prevailing over northern China and high pressure anomalies at mid- and upper troposphere over Mongolia and the adjacent regions. A simplified general circulation model is utilized to examine the possible physical mechanism. A reduced TPSC anomaly can induce a positive geopotential height anomaly at the mid- and upper troposphere and subsequently enhance the climatological high pressure ridge over Mongolia and the adjacent regions. The subsidence associated with the high pressure anomalies tends to suppress the local cloud formation, which increases the net radiation budget, heats the surface, and favors more heatwaves. On the other hand, the surface heating can excite high pressure anomalies at mid- and upper troposphere. The latter further strengthens the upper troposphere high pressure anomalies over Mongolia and the adjacent regions. Through such positive feedback effect, the TPSC is tied to the interdecadal variations of the northern China HWF. (orig.)

  12. GIS-Based Synthetic Measurement of Sustainable Development in Loess Plateau Ecologically Fragile Area—Case of Qingyang, China

    Directory of Open Access Journals (Sweden)

    Chenyu Lu

    2015-02-01

    Full Text Available Synthetic measurement of regional sustainable development has been one of the key issues in the research field of sustainability. In this paper, Qingyang City located in the Loess Plateau ecologically fragile area of Northwest China is used for a case study, and the present study aims to investigate the degree of sustainable development by conducting temporal- and spatial-scale based analysis, with the assessment index system, assessment model and GIS approach well integrated. The results show that the development pattern of Qingyang generally fits the mode of unsustainable development, even in the presence of certain levels of spatial differences. The sustainable development state in ecologically fragile area of China’s Loess Plateau is non-optimistic, which is an uncoordinated status among subsystems of regional sustainable development. Although the level and tendency of regional sustainable development keeps increasing, such enhancement is abnormal. With the rapid deterioration of environmental and natural resources, their inhibitory effect on the economy and society would expand, eventually leading to the slow development rate or the recession of the entire system. The only solution is to change the traditional mode of economic development, to follow the guide of ecological economic conception so that the goal of achieving regional sustainable development strategies could be met ultimately. Meanwhile, the characteristics of different regions should be taken into account in order to achieve optimal spatial structure.

  13. The Persistent Heavy Rainfall over Southern China in June 2010:Evolution of Synoptic Systems and the Effects of the Tibetan Plateau Heating

    Institute of Scientific and Technical Information of China (English)

    李雪松; 罗亚丽; 管兆勇

    2014-01-01

    This study investigates influencing weather systems for and the effect of Tibetan Plateau (TP)’s surface heating on the heavy rainfall over southern China in June 2010, focusing on the four persistent heavy rainfall events during 14-24 June 2010. The ma jor weather systems include the South Asian high, midlatitude trough and ridge, western Pacific subtropical high in the middle troposphere, and shear lines and eastward-moving vortices in the lower troposphere. An ensemble of convection-permitting simulations (CTL) is carried out with the WRF model for these rainfall events, which successfully reproduce the observed evolution of precipitation and weather systems. Another ensemble of simulations (SEN) with the surface albedo over the TP and its southern slope changed artificially to one, i.e., the surface does not absorb any solar heating, otherwise it is identical to CTL, is also performed. Comparison between CTL and SEN suggests that the surface sensible heating of TP in CTL significantly affects the temperature distributions over the plateau and its surroundings, and the thermal wind adjustment consequently changes atmospheric circulations and properties of the synoptic systems, leading to intensified precipitation over southern China. Specifically, at 200 hPa, anticyclonic and cyclonic anomalies form over the western and eastern plateau, respectively, which enhances the southward cold air intrusion along the eastern TP and the divergence over southern China;at 500 hPa, the ridge over the northern plateau and the trough over eastern China are strengthened, the southwesterly flows along the northwestern side of the subtropical high are intensified, and the positive vorticity propagation from the plateau to its downstream is also enhanced significantly;at 850 hPa, the low-pressure vortices strongly develop and move eastward while the southwesterly low-level jet over southern China strengthens in CTL, leading to increased water vapor convergence and upward motion

  14. Influence of environmental factors on spectral characteristics of chromophoric dissolved organic matter (CDOM) in Inner Mongolia Plateau, China

    Science.gov (United States)

    Wen, Z. D.; Song, K. S.; Zhao, Y.; Du, J.; Ma, J. H.

    2016-02-01

    Spectral characteristics of chromophoric dissolved organic matter (CDOM) were examined in conjunction with environmental factors in the waters of rivers and terminal lakes within the Hulun Buir plateau, northeast China. Dissolved organic carbon (DOC), total nitrogen (TN), and total phosphorous (TP) were significantly higher in terminal lakes than rivers waters (p RDA) indicated that the environmental variables total suspended matter (TSM), TN, and electrical conductivity (EC) had a strong correlation with light absorption characteristics, followed by total dissolved solid (TDS) and chlorophyll a. In most sampling locations, CDOM was the dominant non-water light-absorbing substance. Light absorption by non-algal particles often exceeded that by phytoplankton in the plateau waters. Study of these optical-physicochemical correlations is helpful in the evaluation of the potential influence of water quality factors on non-water light absorption in cold plateau water environments. The construction of a correlation between DOC concentration and water quality factors may help contribute to regional estimates of carbon sources and fate for catchment carbon budget assessments.

  15. A mid-Holocene drought interval as evidenced by lake desiccation in the Alashan Plateau, Inner Mongolia,China

    Institute of Scientific and Technical Information of China (English)

    CHEN Fahu; WU Wei; J. A. Holmes; D. B. Madsen; ZHU Yan; JIN Min; C. G. Oviatt

    2003-01-01

    The mid-Holocene in China is traditionally thought to be a warm and humid period with a strong summer monsoon, and is often termed the Holocene Climatic Optimum or Megathermal Period. Here we present lake geomorphologic and lithological evidence from the Alashan Plateau, part of the Mongolian Plateau, that indicates strong lake desiccation during the mid-Holocene. High resolution pollen data from Zhuyeze Lake, at the present summer monsoon margin, is also presented.These data show that present lakes and wetlands in the Juyanze Lake basin west of the Badain Jaran desert, in the Zhuyeze Lake basin between the Badain Jaran and Tengger deserts, and in lakes in the eastern Tengger desert, dried or experienced low lake levels in the mid-Holocene around 5000-7000 cal yr BP. Pollen data further indicate that the vegetation cover declined in both the local areas and in the Qilian Mountains, suggesting the climate was drier than that associatedwith the present Asian summer monsoon. This mid-Holocene drought interval was present throughout a quite large region of the south Inner Mongolian Plateau. Theperiod was also probably colder, at least in the high Asian plateaus and mountains.

  16. Characterizing changes in ecosystem service values in China's eastern Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    JinChang Li; HaiXia Liu; ZhiZhu Su; Yong Liu; YongGang Yang

    2015-01-01

    Human activities such as the implementation of ecological protection projects and expansion of construction land can cause complex land use changes that affect ecosystem service values (ESV). In this study, we investigated changes in ESV in response to land use changes in Ningwu County, in eastern Loess Plateau of China. Our aim is to provide guidance for sustainable land use planning in this region. We used remote sensing to evaluate land use changes, and applied a fast, proxy-based method for evaluating ESV at three points in time:1990, 2000, and 2010. More than 89%of the total ESV in Ningwu County was attributable to woodland and grassland. The ESV in western mountain areas show the greatest increase from 1990 to 2010, but ESV decreased the most in the low-elevation northeastern area of flat terrain. These tradeoffs led to a slight net decrease (1.0%) in Ningwu County's total ESV. Although the decline in ESV was relatively low compared to the rate of economic growth, total ESV was much lower than global and national average levels at the end of the study period.

  17. China's Regional Development and Tibet

    Directory of Open Access Journals (Sweden)

    Kunal Mukherjee

    2016-11-01

    Full Text Available Reviewed: China's Regional Development and Tibet By Rongxing Guo. Singapore: Springer, 2016. xxii + 195 pp. Hardcover: US$ 99.99. ISBN 978-981-287-956-1. E-book: US$ 69.99. ISBN 978-981-287-958-5.

  18. Geodynamics of oceanic plateau and plume head accretion and their role in Phanerozoic orogenic systems of China

    Institute of Scientific and Technical Information of China (English)

    Peter G. Betts; Louis Moresi; Meghan S. Miller; David Willis

    2015-01-01

    We present three 3D numerical models of deep subduction where buoyant material from an oceanic plateau and a plume interact with the overriding plate to assess the influence on subduction dynamics, trench geometry, and mechanisms for plateau accretion and continental growth. Transient instabilities of the convergent margin are produced, resulting in:contorted trench geometry;trench migration parallel with the plate margin; folding of the subducting slab and orocline development at the convergent margin;and transfer of the plateau to the overriding plate. The presence of plume material beneath the oceanic plateau causes flat subduction above the plume, resulting in a“bowed”shaped subducting slab. In plateau-only models, plateau accretion at the edge of the overriding plate results in trench migration around the edge of the plateau before subduction is re-established directly behind the trailing edge of the plateau. The plateau shortens and some plateau material subducts. The presence of buoyant plume material beneath the oceanic plateau has a profound influence on the behaviour of the convergent margin. In the plateau þ plume model, plateau accretion causes rapid trench advance. Plate convergence is accommodated by shearing at the base of the plateau and shortening in the overriding plate. The trench migrates around the edge of the plateau and subduction is re-established well behind the trailing edge of the plateau, effectively embedding the plateau into the overriding plate. A slab window forms beneath the accreted plateau and plume material is transferred from the subducting plate to the over-riding plate through the window. In all of the models, the subduction zone maintains a relatively stable configuration away from the buoyancy anomalies within the downgoing plate. The models provide a dynamic context for plateau and plume accretion in Phanerozoic accretionary orogenic systems such as the East China Orogen and the Central Asian Orogen (Altiads), which

  19. Spatiotemporal analysis of multiscalar drought characteristics across the Loess Plateau of China

    Science.gov (United States)

    Liu, Zhipeng; Wang, Yunqiang; Shao, Mingan; Jia, Xiaoxu; Li, Xuelin

    2016-03-01

    Drought is the most widespread and destructive hazard in arid and semiarid regions, with behaviors that become more complicated under climate change. To provide an overall view of drought conditions across the Loess Plateau of China, two multiscalar drought indices, the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI), were used to identify the regional spatiotemporal characteristics of drought conditions from 1957 to 2012. Climatic data from 54 meteorological stations across the region were used to calculate the SPI and SPEI time series at 1-, 3-, 6-, 12- and 24-month time scales. Subregions with independent drought characteristics and the corresponding representative meteorological stations were identified by principal component analysis to facilitate regional drought monitoring. A temporal trend of drought severity over a 12-month time scale, as detected by the Mann-Kendall test, was mapped for the entire region. The intensity of the increasing trend of drought severity based on the SPEI was weaker than that based on the SPI. The area with a significant increasing trend of drought severity based on the SPEI was only found in the southwest of the region and was much smaller than that based on the SPI. The temporal behavior of drought frequency from January to December differed over different time scales and levels of drought severity. The regional distributions of the drought frequency were mapped for different months. Generally, the drought frequency spatially decreased from southeast to northwest and was higher in the middle of the winter, late spring and early summer. While the drought-hit area also changed with time, it was generally within the central and northwest areas of the region. Drought behaviors identified by the SPI and SPEI also changed with different time scales. Clear differences were also found among the drought characteristics identified by SPI, SPEI and the self-calibrated Palmer Drought

  20. Simulation of Effects of Grassland Degradation on Regional Climate over Sanjiangyuan Region in Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    LIAN Lishu; SHU Jiong

    2009-01-01

    Regional climate model (RegCM3) was applied to explore the possible effects of land use changes (e.g., grassland degradation in this study) on local and regional climate over the Sanjiangyuan region in the Qinghai-Tibet Plateau. Two multiyear (1991-1999) numerical simulation experiments were conducted: one was a control experiment with current land use and the other was a desertification experiment with potential grassland degradation. Preliminary analysis indicated that RegCM3 is appropriate for simulating land-climate interactions, as the patterns of the simulated surface air temperature, the summer precipitation, and the geopotential height fields are consistent with the observed values. The desertification over the Sanjiangyuan region will cause different climate effects in different regions depending on the surrounding environment and climate characteristics. The area with obvious change in surface air temperature inducing by grassland degradation over the Sanjiangyuan region is located in the Qinghai-Tibet Plateau. A winter surface air temperature drop and the other seasons' surface air temperature increase will be observed over the Qinghai-Tibet Plateau based on two numerical simulation experiments. Surface air temperature changes in spring are the largest (0.46℃), and in winter are the smallest (smaller than 0.03℃), indicating an increasing mean annual surface air temperature over the Qinghai-Tibet Plateau. Surface air temperature changes will be smaller and more complex over the surrounding region, with minor winter changes for the regions just outside the plateau and notable summer changes over the north of the Yangtze River. The reinforced summer heat source in the plateau will lead to an intensification of heat low, causing the West Pacific subtropical high to retreat eastward. This will be followed by a decrease of precipitation in summer. The plateau's climate tends to become warm and dry due to the grassland degradation over the Sanjiangyuan

  1. Isolation and Classification of Fungal Whitefly Entomopathogens from Soils of Qinghai-Tibet Plateau and Gansu Corridor in China.

    Science.gov (United States)

    Dong, Tingyan; Zhang, Bowen; Jiang, Yanfang; Hu, Qiongbo

    2016-01-01

    Qinghai-Tibet Plateau and Gansu Corridor of China with distinct geographic and climatic conditions are remote and less disturbed by humans, in which are likely to find some new strains of fungal entomopathogens against B-biotype whiteflies that is a very important invading pest worldwide. In this research, nineteen strains among six species of entomogenous fungi were isolated from the soil samples collected from 32 locations in Qinghai-Tibet Plateau and Gansu Corridor. From the data of isolation rates, it was indicated that the good biodiversity of entomogenous fungi was found in the soil covered good vegetations. On the contrary, no strains were isolated from the desert areas. In addition, the dominant species, Isaria fumosorosea and Metarhizium anisopliae var. anisopliae in the Qinghai-Tibet Plateau are different from the strains of other places based on ITS genetic homology analysis. It was verified that the Qinghai-Tibet Plateau area was less disturbed by human, and the fungi in this place exchanged less compared with other regional species. All of these strains showed the pathogenicity against the B-biotype whitefly with the mortality of more than 30%. However, a few strains of Paecilomyces lilacinus, Lecanicillium psalliotae, Aspergillus ustus, I. fumosorosea and M. anisopliae var. anisopliae had better virulence with LC50s of 0.36-26.44×106 spores/mL on post-treatment day 6-7. Especially, the L. psalliotae strain LpTS01 was the greatest virulence with LC50 of 0.36×106spores/mL and LT50 of 4.23d. Our research thus presents some new insights to discover new entomopathogenic fungal strains used for B-biotype whitefly biocontrol.

  2. Isolation and Classification of Fungal Whitefly Entomopathogens from Soils of Qinghai-Tibet Plateau and Gansu Corridor in China.

    Directory of Open Access Journals (Sweden)

    Tingyan Dong

    Full Text Available Qinghai-Tibet Plateau and Gansu Corridor of China with distinct geographic and climatic conditions are remote and less disturbed by humans, in which are likely to find some new strains of fungal entomopathogens against B-biotype whiteflies that is a very important invading pest worldwide. In this research, nineteen strains among six species of entomogenous fungi were isolated from the soil samples collected from 32 locations in Qinghai-Tibet Plateau and Gansu Corridor. From the data of isolation rates, it was indicated that the good biodiversity of entomogenous fungi was found in the soil covered good vegetations. On the contrary, no strains were isolated from the desert areas. In addition, the dominant species, Isaria fumosorosea and Metarhizium anisopliae var. anisopliae in the Qinghai-Tibet Plateau are different from the strains of other places based on ITS genetic homology analysis. It was verified that the Qinghai-Tibet Plateau area was less disturbed by human, and the fungi in this place exchanged less compared with other regional species. All of these strains showed the pathogenicity against the B-biotype whitefly with the mortality of more than 30%. However, a few strains of Paecilomyces lilacinus, Lecanicillium psalliotae, Aspergillus ustus, I. fumosorosea and M. anisopliae var. anisopliae had better virulence with LC50s of 0.36-26.44×106 spores/mL on post-treatment day 6-7. Especially, the L. psalliotae strain LpTS01 was the greatest virulence with LC50 of 0.36×106spores/mL and LT50 of 4.23d. Our research thus presents some new insights to discover new entomopathogenic fungal strains used for B-biotype whitefly biocontrol.

  3. Isolation and Classification of Fungal Whitefly Entomopathogens from Soils of Qinghai-Tibet Plateau and Gansu Corridor in China

    Science.gov (United States)

    Jiang, Yanfang; Hu, Qiongbo

    2016-01-01

    Qinghai-Tibet Plateau and Gansu Corridor of China with distinct geographic and climatic conditions are remote and less disturbed by humans, in which are likely to find some new strains of fungal entomopathogens against B-biotype whiteflies that is a very important invading pest worldwide. In this research, nineteen strains among six species of entomogenous fungi were isolated from the soil samples collected from 32 locations in Qinghai-Tibet Plateau and Gansu Corridor. From the data of isolation rates, it was indicated that the good biodiversity of entomogenous fungi was found in the soil covered good vegetations. On the contrary, no strains were isolated from the desert areas. In addition, the dominant species, Isaria fumosorosea and Metarhizium anisopliae var. anisopliae in the Qinghai-Tibet Plateau are different from the strains of other places based on ITS genetic homology analysis. It was verified that the Qinghai-Tibet Plateau area was less disturbed by human, and the fungi in this place exchanged less compared with other regional species. All of these strains showed the pathogenicity against the B-biotype whitefly with the mortality of more than 30%. However, a few strains of Paecilomyces lilacinus, Lecanicillium psalliotae, Aspergillus ustus, I. fumosorosea and M. anisopliae var. anisopliae had better virulence with LC50s of 0.36–26.44×106 spores/mL on post-treatment day 6–7. Especially, the L. psalliotae strain LpTS01 was the greatest virulence with LC50 of 0.36×106spores/mL and LT50 of 4.23d. Our research thus presents some new insights to discover new entomopathogenic fungal strains used for B-biotype whitefly biocontrol. PMID:27228109

  4. The First Infrared Telescope in Tibet Plateau, China

    CERN Document Server

    Liu, Li-Yong; Wang, Yi-Ping; Li, Jun-Rong; Zhou, Yun-He; Li, Lin; You, Xian-Long

    2012-01-01

    We plan to install an infrared telescope at the new site of Tibet, China. The primary mirror diameter is 50cm, and the focal ratio F8. The Xenics 640\\times512 near infrared camera is employed, equipped with a dedicated high speed InGaAs detector array, working up to 1.7{\\mu}m. The new site is located on 5100m mountain, near Gar town, Ali, where is an excellent site for both infrared and submillimeter observations. The telescope will be remotely controlled through internet. The goal of IRT is to make site testing, detect variable stars, and search for extrasolar planets.

  5. The impact of afforestation on soil organic carbon sequestration on the Qinghai Plateau, China.

    Directory of Open Access Journals (Sweden)

    Sheng-wei Shi

    Full Text Available Afforestation, the conversion of non-forested land into forest, is widespread in China. However, the dynamics of soil organic carbon (SOC after afforestation are not well understood, especially in plateau climate zones. For a total of 48 shrub- and/or tree-dominated afforestation sites on the Qinghai Plateau, Northwestern China, post-afforestation changes in SOC, total nitrogen (TN, the carbon-to-nitrogen ratio (C/N and soil bulk density (BD were investigated to a soil depth of 60 cm using the paired-plots method. SOC and TN accumulated at rates of 138.2 g C m(-2 yr(-1 and 4.6 g N m(-2 yr(-1, respectively, in shrub-dominated afforestation sites and at rates of 113.3 g C m(-2 yr(-1 and 6.7 g N m(-2 yr(-1, respectively, in tree-dominated afforestation sites. Soil BD was slightly reduced in all layers in the shrub-dominated afforestation plots, and significantly reduced in soil layers from 0-40cm in the tree-dominated afforestation plots. The C/N ratio was higher in afforested sites relative to the reference sites. SOC accumulation was closely related to TN accumulation following afforestation, and the inclusion of N-fixing species in tree-dominated afforestation sites additionally increased the soil accumulation capacity for SOC (p < 0.05. Multiple regression models including the age of an afforestation plot and total number of plant species explained 75% of the variation in relative SOC content change at depth of 0-20 cm, in tree-dominated afforestation sites. We conclude that afforestation on the Qinghai Plateau is associated with great capability of SOC and TN sequestration. This study improves our understanding of the mechanisms underlying SOC and TN accumulation in a plateau climate, and provides evidence on the C sequestration potentials associated with forestry projects in China.

  6. Element concentrations in surface soils of the Coconino Plateau, Grand Canyon region, Coconino County, Arizona

    Science.gov (United States)

    Van Gosen, Bradley S.

    2016-09-15

    This report provides the geochemical analyses of a large set of background soils collected from the surface of the Coconino Plateau in northern Arizona. More than 700 soil samples were collected at 46 widespread areas, sampled from sites that appear unaffected by mineralization and (or) anthropogenic contamination. The soils were analyzed for 47 elements, thereby providing data on metal concentrations in soils representative of the plateau. These background concentrations can be used, for instance, for comparison to metal concentrations found in soils potentially affected by natural and anthropogenic influences on the Coconino Plateau in the Grand Canyon region of Arizona.The soil sampling survey revealed low concentrations for the metals most commonly of environmental concern, such as arsenic, cobalt, chromium, copper, mercury, manganese, molybdenum, lead, uranium, vanadium, and zinc. For example, the median concentrations of the metals in soils of the Coconino Plateau were found to be comparable to the mean values previously reported for soils of the western United States.

  7. MACROPORE FLOW AND MASS WASTING OF GULLIES IN THE LOESS PLATEAU, CHINA

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Due to the extensive gullying from historically excessive erosion in the loess plateau of China, much of this region is being converted to native grass and shrub vegetation. Tunnel scour and mass wasting are important gully erosion processes resulting from preferential flow through macropores ( pores > 1 mm diameter). The objective of this study is to assess the changes with time in macropore flow characteristics of soils on the Loess Plateau following conversion to grass vegetation and the associated degree of mass wasting of gully faces. Ridge areas that had been revegetated for 1 year, 6 years, and > 15 years following tilling, and for 6 years following contour-ditching and the adjacent gully faces were characterized for their macropore and soil matrix properties on a 50 cm by 50 cm area. The total number of macropores increased from 11.6/m2 to 39.6/m2 from 1 to 6 years and to 51.6/m2 after 15 years of revegetation following tillage. The macroporosity increased from 0.0008 m3/m3 to 0.0018 m3/m3 from 1 to 6 years of revegetation following tillage but the lowest macroporosity (0.0005 m3/m3) was 6 years of revegetation following contour-ditching. The contour-ditched area had the lowest infiltration rate (95 m/d) through the soil matrix (areas without macropores) with the tilled areas having similar infiltration rates regardless of the number of years of revegetation (averaged 146 m/d). Due to tunnel scour erosion of macropores during infiltration into the area revegetated for 1 year, pore diameters enlarged by more than 200% resulting in this condition having the highest individual macropore infiltration rates (7967 m/d). Macropores in all other areas were stable with no tunnel scour erosion of macropores. The total capacity for infiltration through macropores increased significantly with time following revegetation. The number of macropores on the gully faces was triple (92.8/m2) and the macroporosity quadruple (0.004 m3/m3) that of the ridge surfaces. The upper

  8. Quantifying the impacts of climate change and ecological restoration on streamflow changes based on a Budyko hydrological model in China's Loess Plateau

    National Research Council Canada - National Science Library

    Liang, Wei; Bai, Dan; Wang, Feiyu; Fu, Bojie; Yan, Junping; Wang, Shuai; Yang, Yuting; Long, Di; Feng, Minquan

    2015-01-01

    Understanding hydrological effects of ecological restoration (ER) is fundamental to develop effective measures guiding future ER and to adapt climate change in China's Loess Plateau (LP). Streamflow ( Q...

  9. Seismic Evidence for the North China Plate Underthrusting Beneath Northeastern Tibet and its Implications for Plateau Growth

    Science.gov (United States)

    Ye, Z.; Gao, R.; Li, Q.; Zhang, H.

    2016-12-01

    The effects of India-Asia collision and the subsequent interaction between the two continents on northeastern Tibet (NE Tibet), i.e., the tectonic transition zone between the Tibetan plateau and the North China craton (NCC) for example, remain uncertain due to inadequate geophysical data coverage in NE Tibet. Here in this research, based on new dataset collected from a dense linear array of 38 broadband seismograph stations, we applied seismic receiver functions (Sp and Ps converted waves) to imaging the lithospheric structure and shear wave splitting (XKS waves) to inspecting the anisotropy in the lithosphere and upper mantle beneath NE Tibet. The seismic array traverses NE Tibet to the westernmost NCC (Alxa block) in an SSW-NNE direction. The lithosphere-asthenosphere boundary (LAB) is clearly defined and appears as a south-dipping interface that runs continuously from the Alxa interior to the Qilian orogen on the S-wave receiver function images. Shear wave splitting measurements show significant lateral variations of seismic anisotropy across NE Tibet. Under joint constraints from both the lithospheric structure imaging and the regional anisotropic regime, combined with previous studies and through a thorough analysis/comparison/integration, we finally constructed a comprehensive lithospheric model of NE Tibet. The model tells that the NCC lithospheric mantle has been persistently underthrust beneath the Qilian orogen in response to on-going convergence/compression between the interior Tibetan plateau and the NCC. This process forms the syntectonic crustal thrust. The regional anisotropic regime can be well accommodated in our interpretation. The lithospheric model summarized here can be well accommodated in a scenario of northeastward migration of stepwise/multiple Aisan mantle lithosphere underthrusting beneath the Tibetan plateau. The multiple Aisan lithospheric blocks underthrust the plateau stepwise in small scale. Our results provide a new section from

  10. Starch granule protein (SGP) polymorphism in cultivated naked barley from Qinghai-Tibet Plateau in China and relationship between SGPs and starch/amylose content

    Institute of Scientific and Technical Information of China (English)

    Zhifen PAN; Yixing ZOU; Tao ZHAO; Guangbing DENG; Xuguang ZHAI; Fang WU; Maoqun YU

    2008-01-01

    Starch granule proteins (SGPs) are minor components bound with starch granule, whose variation could impact starch properties. This study investigated, for the first time, the variation of SGPs in the cultivated naked barley from Qinghai-Tibet Plateau in China. The relation-ship between SGPs and starch content was preliminarily dealt with. Ten major SGPs and 16 types of patterns were present in the 66 cultivated naked varieties, indicating that the SGPs in cultivated naked barley from Qinghai-Tibet Plateau in China are polymorphic. The SGPs of naked barley in Tibet and Sichuan were greatly different and the SGP patterns were specific to sampling regions. Significance test analysis demonstrated that the SGPs described in this study, except for SGP1, could be related with the variation of starch content in the different naked barleys.

  11. 黄土丘陵区退耕草地土壤分离能力季节变化研究%Seasonal Variation of Soil Detachment in Fields under “Grain for Green” in Hilly Regions of Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    王长燕; 郁耀闯

    2016-01-01

    flumes with adjustable bed gradient to investigate changes in soil detachment processes during the plant growing season and their potential affecting factors and especially effects of changes in soil properties and growth of grass roots on soil detachment capacity in two tracts of rehabilitated grasslands different in“Grain for Green”history. One(Tract A)had been planted with Leymus secalinus for 3 years and the other(Tract B)with Medicago sativa for 17 years. [Result]Results show that soil detachment capacity of the two tracts of grasslands declined significantly during the whole growing season(p0.73,ME>0.85). Dynamic changes of the soil properties,such as soil cohesion,bulk density and water-stable aggregates,and growth of the grass roots are the main factors that affect the seasonal variation of soil detachment capacity in the two tracts of rehabilitated grasslands in hilly regions of the Loess Plateau of China. The mean soil detachment capacity of Tract A and Tract B during the whole plant growing season was only 6.32% and 4.79% of that of the control tract,respectively,which suggests that the practice of “Grain for Green” in hilly regions of the Loess Plateau of China is conducive to soil and water conservation in that area. [Conclusion]The findings of this study may serve as theoretic basis and data support in elaborating hydrodynamic mechanisms of the soil detachment processes,evaluating effect of grass roots in fields of“Grain for Green”on soil and water conservation,and rationalizing arrangement of soil and water conservation practices and measures in hilly regions of the Loess Plateau of China.

  12. Land Degradation Monitoring in the Ordos Plateau of China Using an Expert Knowledge and BP-ANN-Based Approach

    Directory of Open Access Journals (Sweden)

    Yaojie Yue

    2016-11-01

    Full Text Available Land degradation monitoring is of vital importance to provide scientific information for promoting sustainable land utilization. This paper presents an expert knowledge and BP-ANN-based approach to detect and monitor land degradation in an effort to overcome the deficiencies of image classification and vegetation index-based approaches. The proposed approach consists of three generic steps: (1 extraction of knowledge on the relationship between land degradation degree and predisposing factors, which are NDVI and albedo, from domain experts; (2 establishment of a land degradation detecting model based on the BP-ANN algorithm; and (3 land degradation dynamic analysis. A comprehensive analysis was conducted on the development of land degradation in the Ordos Plateau of China in 1990, 2000 and 2010. The results indicate that the proposed approach is reliable for monitoring land degradation, with an overall accuracy of 91.2%. From 1990–2010, a reverse trend of land degradation is observed in Ordos Plateau. Regions with relatively high land degradation dynamic were mostly located in the northeast of Ordos Plateau. Additionally, most of the regions have transferred from a hot spot of land degradation to a less changed area. It is suggested that land utilization optimization plays a key role for effective land degradation control. However, it should be highlighted that the goals of such strategies should aim at the main negative factors causing land degradation, and the land use type and its quantity must meet the demand of population and be reconciled with natural conditions. Results from this case study suggest that the expert knowledge and BP-ANN-based approach is effective in mapping land degradation.

  13. Prevalence of Eimeria infection in yaks on the Qinghai-Tibet Plateau of China.

    Science.gov (United States)

    Dong, Hui; Li, Chunhua; Zhao, Qiping; Li, Jing; Han, Hongyu; Jiang, Lianlian; Zhu, Shunhai; Li, Ting; Kong, Chunlin; Huang, Bing; Cai, Jinzhong

    2012-10-01

    Few data are available on the prevalence of Eimeria spp. in yaks. An observational study was conducted to determine the prevalence of coccidial infection in yaks on the Qinghai-Tibet Plateau of China. A total of 324 fecal samples from 4 counties was examined, and oocysts were identified to the species level on the basis of morphological features. Eimeria oocysts were found in 113 (34.9%) samples. The species detected and their prevalence values included the following: Eimeria zuernii (54.9%), E. pellita (35.4%), E. canadensis (33.6%), E. bovis (23.0%), E. cylindrica (16.8%), E. subspherica (16.8%), E. ellipsoidalis (14.1%), E. brasiliensis (13.3%), E. wyomingensis (8.0%), E. alabamensis (7.1%), E. illinoisensis (5.3%), E. auburnensis (4.4%), E. bombayansis (3.5%), and E. bukidnonensis (2.7%). Mixed infections of 2 to 7 species were found in 66.4% of the animals. There was an age-related difference in the prevalence of infection. The highest prevalence (53.3%) was observed in calves, an intermediate prevalence in yearlings (36.1%), and the lowest was in adults (15.6%). The number of oocysts per g of feces was significantly higher in calves than in adults. More Eimeria species were indentified in calves. Eimeria zuernii was the most prevalent species in calves and adults, whereas in yearling yaks E. pellita was most common. The majority of calves and yearlings showed mixed infection, but adults tended to be infected with 1 species. The prevalence and intensity of Eimeria species were found to show statistically significant differences among different regions in Qinghai Province.

  14. Adaptation of potato production to climate change by optimizing sowing date in the Loess Plateau of central Gansu, China

    Institute of Scientific and Technical Information of China (English)

    WANG Chun-ling; SHEN Shuang-he; ZHANG Shu-yu; LI Qiao-zhen; YAO Yu-bi

    2015-01-01

    Potato grows in most part of China, it achieves higher yield and better quality in Gansu Province than in others. With global warming, its growth duration has been prolonged and sowing date become earlier than before. Therefore, to regulate its sowing date and growing period is of great signiifcance for better harvest. In this study, experiments were conducted with six sowing-date treatments of potato in Dingxi, which is in the Loess Plateau of central Gansu Province in Northwest China in 2010. The growth period, morphological index and change in yield and their relationships with temperature, precipitation, and other climatic factors were investigated for each treatment. Results show that the crop with different sowing dates experienced different climate conditions, leading to distinct growth duration, plant height, and leaf area index. The growth duration was shortened due to a delay in sowing date. For each 15-day delay in sowing, the growth duration was reduced by 12 days on average. A signiifcant linear relationship was found between numbers of days either from seeding to emergence or from lfowering to harvest and mean temperature over the corresponding period. Dry matter accumulation, tuber fresh weight, and ifnal yield were al decreased because of insufifcient cumulative temperature over the shorter growing periods. Marked differences in tuber yield were discovered among the six treatments of sowing date, the potato planted on May 27 giving the highest yield. The potato planted either earlier or later would produce invariably lower yield than the treatment of May 27. Late May therefore can be taken as the optimum sowing time of potato in this region because the crop can ful y utilize thermal resource. We conclude that to postpone sowing time is a good practice for potato production to adapt to climate warming in the Loess Plateau of central Gansu, China.

  15. The impact of afforestation on soil organic carbon sequestration on the Qinghai Plateau, China.

    Science.gov (United States)

    Shi, Sheng-wei; Han, Peng-fei; Zhang, Ping; Ding, Fan; Ma, Cheng-lin

    2015-01-01

    Afforestation, the conversion of non-forested land into forest, is widespread in China. However, the dynamics of soil organic carbon (SOC) after afforestation are not well understood, especially in plateau climate zones. For a total of 48 shrub- and/or tree-dominated afforestation sites on the Qinghai Plateau, Northwestern China, post-afforestation changes in SOC, total nitrogen (TN), the carbon-to-nitrogen ratio (C/N) and soil bulk density (BD) were investigated to a soil depth of 60 cm using the paired-plots method. SOC and TN accumulated at rates of 138.2 g C m(-2) yr(-1) and 4.6 g N m(-2) yr(-1), respectively, in shrub-dominated afforestation sites and at rates of 113.3 g C m(-2) yr(-1) and 6.7 g N m(-2) yr(-1), respectively, in tree-dominated afforestation sites. Soil BD was slightly reduced in all layers in the shrub-dominated afforestation plots, and significantly reduced in soil layers from 0-40cm in the tree-dominated afforestation plots. The C/N ratio was higher in afforested sites relative to the reference sites. SOC accumulation was closely related to TN accumulation following afforestation, and the inclusion of N-fixing species in tree-dominated afforestation sites additionally increased the soil accumulation capacity for SOC (p sequestration. This study improves our understanding of the mechanisms underlying SOC and TN accumulation in a plateau climate, and provides evidence on the C sequestration potentials associated with forestry projects in China.

  16. The Formation of Barrier Winds East of the Loess Plateau and Their Effects on Dispersion Conditions in the North China Plains

    Science.gov (United States)

    Hu, Xiao-Ming; Li, Xingliang; Xue, Ming; Wu, Dui; Fuentes, Jose D.

    2016-10-01

    The North China Plain (NCP) to the east of the Loess Plateau is one of the most heavily polluted areas in the world. Weak surface flow in the western part of the NCP exacerbates the air pollution in this region. Deceleration of low-level flow when approaching the Loess Plateau, together with enhanced roughness associated with large cities, were previously ascribed as the causes for low wind speeds in the NCP. Using numerical simulations with a one-layer dispersion model, we identify that dynamic modification of airflow by the Loess Plateau (not just simple deceleration due to mountain blocking) plays an important role in reducing the wind speed over the NCP. Dynamically-induced northerly barrier winds, superimposed on the prevailing southerly/south-easterly flow, reduce the wind speed in a 50-100 km wide region to the east of the Plateau, partially explaining the weak winds in the western part of the NCP. Poor dispersion conditions due to weak horizontal winds likely contribute to the accumulation of pollutants in this region.

  17. One century of air deposition of hydrocarbons recorded in travertine in North Tibetan Plateau, China: Sources and evolution.

    Science.gov (United States)

    Yuan, Guo-Li; Wu, Ming-Zhe; Sun, Yong; Li, Jun; Li, Jing-Chao; Wang, Gen-Hou

    2016-08-01

    The characteristic distribution patterns of hydrocarbons have been used for fingerprinting to identify their sources. The historical air depositions of hydrocarbons recorded in natural media help to understand the evolution of the air environment. Travertine is a natural acceptor of air deposition that settles on the ground layer by layer. To reconstruct the historical air environment of hydrocarbons in the North Tibetan Plateau (NTP), a unique background region, twenty-seven travertine samples were collected systematically from a travertine column according to its precipitated year. For each sample, the precipitated year was dated while n-alkanes and polycyclic aromatic hydrocarbons (PAHs) were determined. Based on source identification, the air environment of hydrocarbons in the past century was studied for the region of NTP. Before World War II, the anthropogenic sources of hydrocarbons showed little influence on the air environment. During World War II and China's War of Liberation, hydrocarbons increased significantly, mainly from the use of fossil fuels. Between 1954 and 1963, hydrocarbons in the air decreased significantly because the sources of petroleum combustion decreased. From the mid-1960s through the end of the 1990s, air hydrocarbons, which mainly originated from biomass burning, increased gradually because agriculture and animal husbandry were developing steadily in Tibet and China. From the late 1990s, hydrocarbons in the atmosphere increased rapidly due to the rapid increase of tourism activities, which might increase hydrocarbon emissions from traffic. The reconstruction of the historical air hydrocarbons in NTP clearly reflects the evolution of the region and global development.

  18. Soil Microbial Community Composition During Natural Recovery in the Loess Plateau, China

    Institute of Scientific and Technical Information of China (English)

    XIAO Lie; LIU Guo-bin; XUE Sha; ZHANG Chao

    2013-01-01

    This study aimed to determine the characteristics of soil microbial community composition and its relationship with soil chemical properties during natural recovery in the Loess Plateau. The soil microbial community composition was analyzed by comparing the soil microbial phospholipid fatty acids (PLFAs) of eight croplands abandoned for 1, 3, 5, 10, 13, 15, 20, and 30 yr in the Dunshan watershed, northern Loess Plateau, China. The results showed that soil organic carbon, total nitrogen, soil microbial biomass carbon, and soil microbial biomass nitrogen signiifcantly increased with the abandonment duration, whereas the metabolic quotient signiifcantly decreased. The Shannon richness and Shannon evenness of PLFAs signiifcantly increased after 10 yr of abandonment. Gram-negative, Gram-positive, bacterial, fungal, and total PLFAs linearly increased with increased abandonment duration. Redundancy analysis showed that the abandonment duration was the most important environmental factor in determining the PLFA microbial community composition. The soil microbial PLFAs changed from anteiso-to iso-, unsaturated to saturated, and short-to long-chain during natural recovery. Therefore, in the Loess Plateau, cropland abandonment for natural recovery resulted in the increase of the soil microbial PLFA biomass and microbial PLFA species and changed the microbial from chemolithotrophic to a more heterotrophic community.

  19. The Effects of the Thermal Anomalies over the Tibetan Plateau and Its Vicinities on Climate Variability in China

    Institute of Scientific and Technical Information of China (English)

    钱永甫; 张艳; 黄燕燕; 黄樱; 姚永红

    2004-01-01

    The evident effects of the thermal anomalies over the Tibetan Plateau (TP) and its vicinities are summarized and discussed in this paper. By the singular value decomposition (SVD) technique and numerical simulations of the effect of the snow depth anomaly over the TP, it is shown that the snow depth anomaly, especially in winter, is one of the factors influencing precipitation in China, and the winter snow anomaly is more important than the spring one. The relations between the sensible heat anomaly over the TP and the intensity of the South China Sea summer monsoon (SCSSM) are studied, too, and two key areas of the sensible heat anomaly over the TP are found. The relationships between the South Asia High (SAH)and the precipitation in the years with typical droughts or floods in the mid to lower valleys of the Yangtze River (MLVYR) and North China are investigated in some detail. It is found that not only the intensity of the SAH over the TP, but also the 100-hPa height in a large area influences the precipitation in the above two regions. The effects of the SAH on the onsets of the tropical Asian summer monsoon (TASM) including the SCSSM and the tropical Indian summer monsoon (TISM) are studied as well. It is found that the onset times of both the SCSSM and the TISM are highly dependent upon the latitudinal position of the SAH center.

  20. Loess in Kunlun Mountains and its implications on desert development and Tibetan Plateau uplift in west China

    Institute of Scientific and Technical Information of China (English)

    FANG; Xiaomin(方小敏); Lü; Lianqing(吕连清); YANG; Shengli(杨胜利); LI; Jijun(李吉均); AN; Zhisheng(安芷生); JIANG; Pingan(蒋平安); CHEN; Xiuling(陈秀玲)

    2002-01-01

    Loess on the northern slope of Kunlun Mountains is the synchronous deposition of the Taklimakan Desert. The paleomagnetism and climatic records of an over 80 m loess-paleosol sequence on the highest river terrace at the foot of Kunlun Mountains show that the loess formed at ~ 880 ka B.P., suggesting a roughly synchronous occurrence of the present-like air circulation and extremely dry climate and the initial desert. The uplift of the Tibetan-Pamir Plateau and Tian-shan Mountains may initiate these events. The rise of the plateau and adjacent mountains caused the drying and desertification of China inland and Tarim Basin, which was dramatically enhanced at ~ 500 ka B.P., leading the desert to expand to its present scale. Global change just overprints this drying trend. Local climate response to global change both in long-term evolution and glacial-interglacial cycles manifests that the stronger the westerlies, the more the precipitation. But the heat-moisture pattern seems still similar to that in the Asian monsoon region.

  1. Differences in hydrological responses for different vegetation types on a steep slope on the Loess Plateau, China

    Science.gov (United States)

    Duan, Liangxia; Huang, Mingbin; Zhang, Luodan

    2016-06-01

    Extensive vegetation restoration practices have been implemented to control soil erosion on the Loess Plateau, China. However, no strict guidelines are available to determine the most suitable plant species for vegetation restoration within a given area. The objective of this study was to quantify the changes of each component (soil water storage, surface runoff, and actual evapotranspiration) of a water balance model and soil loss over time under eight different vegetation types, and to further determine the optimal vegetation type for soil and water conservation and sustainable ecological restoration on the steep slopes (>25°) on the Loess Plateau. The results indicated that vegetation type substantially affected soil water storage and that the greatest soil water storage in both the shallow (0-2 m) and the deep soil layers (2-5 m) occurred under Bothriochloa ischaemum L. (BOI). Vegetation type also affected surface runoff and soil losses. The most effective vegetation types for reducing soil erosion were BOI and Sea-buckthorn (Hippophae rhamnoides L.), while Chinese pine (Pinus tabulaeformis Carr.) and Chinese pine + Black locust (Robinia pseudoacacia L.) were the most ineffective types. Soil water dynamics and evapotranspiration varied considerably among the different vegetation types. A soil water surplus was only found under BOI, while insufficient water replenishment existed under the other seven vegetation types. The higher water consumption rates of the seven vegetation types could result in soil desiccation, which could lead to severe water stresses that would adversely affect plant growth. This study suggested that both vegetation type and its effect on controlling soil erosion should be considered when implementing vegetation restoration and that BOI should be highly recommended for vegetation restoration on the steep slopes of the Loess Plateau. A similar approach to the one used in this study could be applied to other regions of the world confronted

  2. 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.

  3. An experimental method to verify soil conservation by check dams on the Loess Plateau, China.

    Science.gov (United States)

    Xu, X Z; Zhang, H W; Wang, G Q; Chen, S C; Dang, W Q

    2009-12-01

    A successful experiment with a physical model requires necessary conditions of similarity. This study presents an experimental method with a semi-scale physical model. The model is used to monitor and verify soil conservation by check dams in a small watershed on the Loess Plateau of China. During experiments, the model-prototype ratio of geomorphic variables was kept constant under each rainfall event. Consequently, experimental data are available for verification of soil erosion processes in the field and for predicting soil loss in a model watershed with check dams. Thus, it can predict the amount of soil loss in a catchment. This study also mentions four criteria: similarities of watershed geometry, grain size and bare land, Froude number (Fr) for rainfall event, and soil erosion in downscaled models. The efficacy of the proposed method was confirmed using these criteria in two different downscaled model experiments. The B-Model, a large scale model, simulates watershed prototype. The two small scale models, D(a) and D(b), have different erosion rates, but are the same size. These two models simulate hydraulic processes in the B-Model. Experiment results show that while soil loss in the small scale models was converted by multiplying the soil loss scale number, it was very close to that of the B-Model. Obviously, with a semi-scale physical model, experiments are available to verify and predict soil loss in a small watershed area with check dam system on the Loess Plateau, China.

  4. Multiproxy biomarker, isotopic and pollen reconstructions of the middle to late Holocene paleoclimate of the Loess Plateau in centre China

    Science.gov (United States)

    Sun, H.; Seki, O.; Zhou, A.; Chen, F.; Schouten, S.; Toney, J. L.; Bendle, J.

    2011-12-01

    The Asian monsoon is a key component of the earth's climate system that directly affects the livelihood of 50 million people on the loess plateau of central China. At the far edge of monsoonal influence, this region is especially vulnerable to future changes in temperature and evaporation / precipitation. Therefore, paleoclimatic information on the natural sensitivity of the region to changes in monsoon driven aridity are crucial. Despite the need for multiproxy records of Holocene climate from this region, reconstructions are rare, because of the low resolution of loess deposits and the scarcity of other paleoclimate archives (e.g. natural lakes, speleothems). Here we present multiple proxy records from Tianchi lake, one of the few nature lakes on the loess plateau and central China. The chronology is well constrained by a high-resolution (20 AMS 14C dates) radiocarbon age-model, spanning the past 6200 years. Here we present pollen, Glycerol dibiphytanyl glycerol tetraethers (GDGTs), lake macrophyte and higher plant-wax biomarkers to reconstruct regional climate change during the middle to late Holocene. Evidence from pollen data suggest that deciduous trees decreased from 6200 cal yr BP and then more rapidly from 1000 yr BP. Modern and downcore molecular distribution patterns of n-alkanes and n-alkanoic acids, especially n-alkane Paq values, suggest increasing relative abundance of macrophytes over this time, which we interpret (based on lake morphology) as decreasing lake-level. Using the recent Sun et al (2011) regional calibration we derive mean annual GDGT based temperatures (MBT/CBT-MATs) with reasonable ranges. Our temperature reconstruction closely correlates on millennial to centennial timescales with the independent D/H measurements on C28 fatty acid methyl esters (C28 FAMEs), whose signal is assumed to derive primarily from terrestrial plant waxes and the δD values to reflect local changes in relative humidity. Comparisons of our independent GDGT

  5. [Soil particle size distribution and its fractal dimension among degradation sequences of the alpine meadow in the source region of the Yangtze and Yellow River, Qinghai-Tibetan Plateau, China].

    Science.gov (United States)

    Wei, Mao-Hong; Lin, Hui-Long

    2014-03-01

    The alpine meadow in the source region of the Yangtze and Yellow River is suffering serious deterioration. Though great efforts have been put into, the restoration for the degraded grassland is far from being effective, mainly due to poor understanding of the degradation mechanism of alpine meadow in this region. In order to clarify the formation mechanism of degradation grassland and provide the new ideas for restoration, degradation sequences of the alpine meadow in the source region of the Yangtze and Yellow River were taken as target systems to analyze the soil particle size distribution, the fractal dimension of the soil particle size, and the relationship between soil erosion modulus and fractal dimension. The results showed that, with increasing grassland degradation, the percentage contents of clay increased while the percentage contents of silt sand and very fine sand showed a decreasing trend. The fractal dimension presented a positive correlation with clay among the degradation sequences while negative correlations were found with very fine sand and silt sand. The curvilinear regression of fractal dimension and erosion modulus fitted a quadratic function. Judged by the function, fractal dimension 2.81 was the threshold value of soil erosion. The threshold value has an indicative meaning on predicting the breakout of grazing-induced erosion and on restoration of the degraded grassland. Taking fractal dimension of 2.81 as the restoration indicator, adoption of corresponding measures to make fractal dimension less than 2.81, would an effective way to restore the degradation grassland.

  6. Effect of apple production base on regional water cycle in Weibei upland of the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Weibei upland, located in southern part of the Loess Plateau, is a commercial apple production base in China. The enlargement of apple-planting area has a great impact on the regional water cycle. The effects of different land use on hydrological parameters are compared and studied in this paper. The main results are as follows: (1) The initial and steady infiltration rates in apple orchard are higher than those in other land use types such as grassland, idle land and farmland. Their initial rates of infiltration are 0.823 cm/min, 0.215 cm/min, 0.534 cm/min and 0.586 cm/min in apple orchard, grassland, idle land and farmland respectively. Their steady infiltration rates are 0.45 cm/min, 0.038 cm/min, 0.191 cm/min and 0.155 cm/min respectively. (2) There is no runoff generated in plot of apple orchard in all 8 storm events in observed natural rainfalls, while runoff is generated in winter wheat plot, com plot and alfalfa plot with runoff coefficients of 2.39%, 1.58% and 0.31% respectively. (3) The transpiration of apple trees is strong and thus soil moisture is gradually depleted. The average soil water contents in 3-9 m soil profile in Changwu plots with apple trees of 14 and 32 years in age are 11.77% and 11.59% and in Luochuan plots with those of 15 and 28 years in age are 11.7% and 11.59% respectively, which are nearly 9.0% of wilting moisture of Changwu soil and 8.6% of wilting moisture of Luochuan soil. The pathway of rainfall percolating to groundwater is hindered by dry soil profile.

  7. Development of three PCR assays for the differentiation between Echinococcus shiquicus, E. granulosus (G1 genotype), and E. multilocularis DNA in the co-endemic region of Qinghai-Tibet plateau, China.

    Science.gov (United States)

    Boufana, Belgees; Umhang, Gérald; Qiu, Jiamin; Chen, Xingwang; Lahmar, Samia; Boué, Franck; Jenkins, David; Craig, Philip

    2013-04-01

    To investigate echinococcosis in co-endemic regions, three polymerase chain reaction (PCR) assays based on the amplification of a fragment within the NADH dehydrogenase subunit 1 (ND1) mitochondrial gene were optimized for the detection of Echinococcus shiquicus, Echinococcus granulosus G1, and Echinococcus multilocularis DNA derived from parasite tissue or canid fecal samples. Specificity using parasite tissue-derived DNA was found to be 100% except for E. shiquicus primers that faintly detected E. equinus DNA. Sensitivity of the three assays for DNA detection was between 2 and 10 pg. Ethanol precipitation of negative PCR fecal samples was used to eliminate false negatives and served to increase sensitivity as exemplified by an increase in detection from 0% to 89% of E. shiquicus coproDNA using necropsy-positive fox samples.

  8. Circulation and its seasonal variability in region around the Kerguelen Plateau

    Institute of Scientific and Technical Information of China (English)

    Shi Jiuxin(史久新); Le Kentang(乐肯堂); Byung Ho Choi

    2002-01-01

    A coupled ice-ocean isopycnal numerical model of the Southern Ocean is established to study the circulation and its seasonal variability in the region around the Kerguelen Plateau. An analysis of the simulated results shows significant stripe-like structure and non-zonal feature of the Antarctic Circumpolar Current (ACC) in this region. ACC begins to bifurcate and to turn its direction before meeting the plateau. The southernmost branch of ACC is near to the Antarctic coast and displays its strong interaction with the westward Antarctic Slope Current. The northern branch of ACC has a tendency of annual variations while the southern one varies in a semiannual cycle. The variation phases of both branches are coincident with that of the wind stress in this region.

  9. Air Temperature Changes over the Tibetan Plateau and Other Regions in the Same Latitudes and the Role of Ozone Depletion

    Institute of Scientific and Technical Information of China (English)

    ZHANG Renhe; ZHOU Shunwu

    2009-01-01

    Using radiosonde and satellite observations, we investigated the trends of air temperature changes over the Tibetan Plateau (TP) in comparison with those over other regions in the same latitudes from 1979 to 2002. It is shown that over the TP, the trends of air temperature changes in the upper troposphere to lower stratosphere were out of phase with those in the lower to middle troposphere. Air temperature decreased and a decreasing trend appeared in the upper troposphere to lower stratosphere. The amplitude of the annual or seasonal mean temperature decreases over the TP was larger than that over the whole globe. In the lower to middle troposphere over the TP, temperature increased, and the increasing trend was stronger than that over the non-plateau regions in the same latitudes in the eastern part of China. Meanwhile, an analysis of the satellite observed ozone data in the same period of 1979-2002 shows that over the TP, the total ozone amount declined in all seasons, and the ozone depleted the most compared with the situations in other regions in the same latitudes. It is proposed that the difference between the ozone depletion over the TP and that over other regions in the same latitudes may lead to the difference in air temperature changes. Because of the aggravated depletion of ozone over the TP, less (more) ultraviolet radiation was absorbed in the upper troposphere to lower stratosphere (lower to middle troposphere) over the TP, which favored a stronger cooling in the upper troposphere to lower stratosphere, and an intenser heating in the lower to middle troposphere over the TP. Therefore, the comparatively more depletion of ozone over the TP is possibly a reason for the difference between the air temperature changes over the TP and those over other regions in the same latitudes.

  10. Impact of gully on soil moisture of shrubland in wind-water erosion crisscross region of the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    HUO Zhu; SHAO Ming-An; LISI

    2008-01-01

    The most serious erosion on the Loess Plateau of China exists in the wind-water erosion crisscross region where the annual precipitation is about 400 ram,the ecological environment is very fragile,and water is the key limiting factor for improving the environment.In this study,changes of soil moisture content for Caragana korshinskii Kom.shrubland in the gully bank of the Loess Plateau were studied using the methods of soil sampling and neutron probe.A typical gully (75 m long,28 m wide,and 10 m deep) was selected,and six neutron probe access tubes (6 m long) were installed at points 50,100,200,300,400,and 500 cm from the gully border for obtaining soil moisture data from July to October 2004 at approximately 10 d intervals.Soil samplings were simultaneously carried out for moisture determination at the six points.Results showed that the soil moisture of the shrubland in the gully bank significantly varied between 300 and 400 cm in the horizontal direction and up to 600 cm in vertical direction of the gully.Seasonal changes in soil moisture revealed a curve with a single peak that occurred at the end of August or early September.A linear regression equation was fit for soil water storage and the distance from the gully border,with coefficients depending on rainfall characteristics,sampling point,and time of measurement.

  11. Quantitative assessment of resource-use efficient cropping systems: a case study for Ansai in the Loess Plateau of China

    NARCIS (Netherlands)

    Lu, C.H.; Ittersum, van M.K.; Rabbinge, R.

    2003-01-01

    Severe soil erosion and food security problems are the most important issues in the Loess Plateau of northern China, which are closely related to the over-cultivation and poor management of marginal land resources. Alleviation of these unsustainability problems requires, among many other things, alt

  12. Nebkha development and its relationship to environmental change in the Alaxa Plateau, China

    Science.gov (United States)

    Wang, Xunming; Xiao, Honglang; Li, Jinchang; Qiang, Mingrui; Su, Zhizu

    2008-11-01

    Extensive nebkha areas develop mainly under the control of aeolian processes, and their sediments record information on regional environmental changes during different periods. Such areas have developed on the dry riverbeds and deserted arable lands of China’s Alaxa Plateau, Taklimakan, and Kumutage deserts. In this paper, we studied nebkhas that had developed in the Heicheng Juyan region to determine their CaCO3 contents, particle size distributions, and creation dates. Extensive human activities have occurred in this region since at least in the late Tang Dynasty (618 907 ad). Although historical records show that most of the region’s rivers dried up around 1372, surface water persisted in some areas until the early Qing Dynasty (1644 1911 ad). After the 1600s, extensive nebkhas began to develop due to drying of the region’s rivers. The early stages of nebkha development were controlled by both the sediment supply and the regional wind regime, whereas late stages were controlled primarily by variations in wind activity. In the Alaxa Plateau, it took about 100 years for arable lands and riverbeds to evolve into gobi deserts, and during this time, several phases occurred with different levels of wind activity. The land degradation processes in this region are mainly controlled by surface water resources, and the impact of human activities such as reclamation on land degradation appear to have been overestimated in previous studies.

  13. EU-China cooperation on regional policy

    Directory of Open Access Journals (Sweden)

    Eva Minarčíková

    2016-03-01

    Full Text Available Although the European Union and China are different in terms of area, population, economic, social, political and cultural development, both of them have to face similar challenge – the significant regional disparities and unbalanced regional development. Based on this the EU-China cooperation on regional policy has been launched and there is huge potential to develop mutual learning initiatives to allow their regions developed. The main aim of this paper is to outline the trends in evolution and perspectives of EU-China cooperation on regional policy.

  14. International Comparison and Implications of Agricultural Development in Foreign Low Latitude Plateau Regions for Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    Yan; LUO; Yan; YANG; Rui; CHEN; Wei; WU; Ziyun; PENG; Liangzheng; CHEN; Xuelin; LI

    2013-01-01

    Climatic characteristics of foreign low latitude plateau regions are firstly introduced.Then,experience and lessons of major foreign low latitude plateau countries in developing modern agriculture are analyzed,including Indian three agricultural revolutions and agricultural informationization development,application of agricultural biotechnology in Brazil,trade liberalization and economic de-agriculture of Mexico,and Argentina,Saudi Arabia and South Africa attaching great importance to developing modern agriculture relying on science and technology and paying close attention to resource conservation and environmental protection.Combining natural and social resource characteristics of Yunnan plateau agriculture,pertinent implications and recommendations for modern agricultural development in Yunnan are put forward.Specifically,these include strengthening agricultural sci-tech research and development,and extension and application;transforming agricultural development model;enhancing agricultural resource conservation and environmental protection;accelerating developing mountain organic ecological agriculture and autumn agriculture;reinforcing urban and rural integration to develop plateau characteristic agriculture on the basis of local actual conditions.

  15. Impact of the Loess Plateau on the atmospheric boundary layer structure and air quality in the North China Plain: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xiao-Ming, E-mail: xhu@ou.edu [Center for Analysis and Prediction of Storms, and School of Meteorology, University of Oklahoma, Norman, OK 73072 (United States); Ma, ZhiQiang, E-mail: zqma@ium.cn [Institute of Urban Meteorology, China Meteorological Administration, Beijing 100089 (China); Lin, Weili [Key Laboratory for Atmospheric Chemistry, Center for Atmospheric Watch and Services, Chinese Academy of Meteorological Sciences, Beijing, 100081 (China); Zhang, Hongliang; Hu, Jianlin [Department of Civil and Environmental Engineering, University of California, Davis, CA 95616 (United States); Wang, Ying; Xu, Xiaobin [Key Laboratory for Atmospheric Chemistry, Center for Atmospheric Watch and Services, Chinese Academy of Meteorological Sciences, Beijing, 100081 (China); Fuentes, Jose D. [Department of Meteorology, Pennsylvania State University, University Park, PA 16802 (United States); Xue, Ming [Center for Analysis and Prediction of Storms, and School of Meteorology, University of Oklahoma, Norman, OK 73072 (United States)

    2014-11-15

    The North China Plain (NCP), to the east of the Loess Plateau, experiences severe regional air pollution. During the daytime in the summer, the Loess Plateau acts as an elevated heat source. The impacts of such a thermal effect on meteorological phenomena (e.g., waves, precipitation) in this region have been discussed. However, its impacts on the atmospheric boundary layer structure and air quality have not been reported. It is hypothesized that the thermal effect of the Plateau likely modulates the boundary layer structure and ambient concentrations of pollutants over the NCP under certain meteorological conditions. Thus, this study investigates such effect and its impacts using measurements and three-dimensional model simulations. It is found that in the presence of daytime westerly wind in the lower troposphere (∼ 1 km above the NCP), warmer air above the Loess Plateau was transported over the NCP and imposed a thermal inversion above the mixed boundary layer, which acted as a lid and suppressed the mixed layer growth. As a result, pollutants accumulated in the shallow mixed layer and ozone was efficiently produced. The downward branch of the thermally-induced Mountain-Plains Solenoid circulation over the NCP contributed to enhancing the capping inversion and exacerbating air pollution. Previous studies have reported that low mixed layer, a factor for elevated pollution in the NCP, may be caused by aerosol scattering and absorption of solar radiation, frontal inversion, and large scale subsidence. The present study revealed a different mechanism (i.e., westerly warm advection) for the suppression of the mixed layer in summer NCP, which caused severe O{sub 3} pollution. This study has important implications for understanding the essential meteorological factors for pollution episodes in this region and forecasting these severe events. - Highlights: • Low mixed layer exacerbates air pollution over the North China Plain (NCP) • Warm advection from the Loess

  16. Satellite Monitoring the Spatial-Temporal Dynamics of Desertification in Response to Climate Change and Human Activities across the Ordos Plateau, China

    Directory of Open Access Journals (Sweden)

    Qiang Guo

    2017-05-01

    Full Text Available The Ordos Plateau, a typical semi-arid area in northern China, has experienced severe wind erosion events that have stripped the agriculturally important finer fraction of the topsoil and caused dust events that often impact the air quality in northern China and the surrounding regions. Both climate change and human activities have been considered key factors in the desertification process. This study used multi-spectral Landsat Thematic Mapper (TM, Enhanced Thematic Mapper Plus (ETM+ and Operational Land Imager (OLI remote sensing data collected in 2000, 2006, 2010 and 2015 to generate a temporal series of the modified soil-adjusted vegetation index (MSAVI, bare soil index (BSI and albedo products in the Ordos Plateau. Based on these satellite products and the decision tree method, we quantitatively assessed the desertification status over the past 15 years since 2000. Furthermore, a quantitative method was used to assess the roles of driving forces in desertification dynamics using net primary productivity (NPP as a commensurable indicator. The results showed that the area of non-desertification land increased from 6647 km2 in 2000 to 15,961 km2 in 2015, while the area of severe desertification land decreased from 16,161 km2 in 2000 to 8,331 km2 in 2015. During the period 2006–2015, the effect of human activities, especially the ecological recovery projects implemented in northern China, was the main cause of desertification reversion in this region. Therefore, ecological recovery projects are still required to promote harmonious development between nature and human society in ecologically fragile regions like the Ordos Plateau.

  17. 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.

  18. Ecology of macrozoobenthic communities in two plateau lakes of Southwest China

    Institute of Scientific and Technical Information of China (English)

    CUI Yongde; WANG Hongzhu

    2008-01-01

    Ecological studies on macrozoobenthos were conducted in two small plateau lakes in the Yunnan-Guizhou Plateau, Southwest China: Xingyun Lake (XL), a eutrophic lake whose main source of primary production was phytoplankton (Chl a=99.76±24.01 μg/L), and Yangzong Lake (YL), a mesotrophic lake. Sampling was carried out from October 2002 to May 2004. Altogether 23 benthic taxa were identified in XL and 21 taxa in YL. The density of benthos in XL was much lower than that in YL, but the biomass was about equal in the two lakes, being I 423 ind/m2 and 8.71 g/m2 in XL and 4 249 ind/m2 and 8.60 g/m2 in YL. The dominant species were Limnodrilus hoffmeisteri, Branchiura sowerbyi, Aulodrilus pluriseta and Chironomus sp. in XL and Limnodrilus hoffmeisteri, Aulodrilus pluriseta and Bellamya sp. in YL. Seasonal fluctuation occurred, showing richer species in summer and winter, but the density and biomass varied in different ways in the two lakes. Analyses on functional feeding groups indicate that collector-gatherers were predominant, but the relative abundances of other groups were different. Stepwise multiple regression analysis demonstrated that the water depth, conductivity and chlorophyll a were the key factors affecting macrozoobenthic abundance in the lakes.

  19. Application of SCS Model in Estimation of Runoff from Small Watershed in Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    LIU Xianzhao; LI Jiazhu

    2008-01-01

    Soil Conservation Service (SCS) model,developed by U.S.Soil Conservation Service in 1972,has been widely applied in the estimation of runoff from an small watershed.In this paper,based on the remote sensing geo-information data of land use and soil classification all obtained from Landsat images in 1996 and 1997 and conventional data of hydrology and meteorology,the SCS model was investigated for simulating the surface runoff for single rainstorm in Wangdonggou watershed,a typical small watershed in the Loess Plateau,located in Changwu County of Shaanxi Province of China.Wangdonggou watershed was compartmentalized into 28 sub-units according to natural draining division,and the table of curve number (CN) values fitting for Wangdonggou watershed was also presented.During the flood period from 1996 to 1997,the hydrograph of calculated runoff process using the SCS model and the hydrograph of observed runoff process coincided very well in height as well as shape,and the model was of high precision above 75%.It is indicated that the SCS model is legitimate and can be successfully used to simulate the runoff generation and the runoff process of typical small watershed based on the remote sensing geo-information in the Loess Plateau.

  20. Bacterial community structure in two permafrost wetlands on the Tibetan Plateau and Sanjiang Plain, China.

    Science.gov (United States)

    Yun, Juanli; Ju, Yiwen; Deng, Yongcui; Zhang, Hongxun

    2014-08-01

    Permafrost wetlands are important methane emission sources and fragile ecosystems sensitive to climate change. Presently, there remains a lack of knowledge regarding bacterial communities, especially methanotrophs in vast areas of permafrost on the Tibetan Plateau in Northwest China and the Sanjiang Plain (SJ) in Northeast China. In this study, 16S rRNA-based quantitative PCR (qPCR) and 454 pyrosequencing were used to identify bacterial communities in soils sampled from a littoral wetland of Lake Namco on the Tibetan Plateau (NMC) and an alluvial wetland on the SJ. Additionally, methanotroph-specific primers targeting particulate methane monooxygenase subunit A gene (pmoA) were used for qPCR and pyrosequencing analysis of methanotrophic community structure in NMC soils. qPCR analysis revealed the presence of 10(10) 16S rRNA gene copies per gram of wet soil in both wetlands, with 10(8) pmoA copies per gram of wet soil in NMC. The two permafrost wetlands showed similar bacterial community compositions, which differed from those reported in other cold environments. Proteobacteria, Actinobacteria , and Chloroflexi were the most abundant phyla in both wetlands, whereas Acidobacteria was prevalent in the acidic wetland SJ only. These four phyla constituted more than 80 % of total bacterial community diversity in permafrost wetland soils, and Methylobacter of type I methanotrophs was overwhelmingly dominant in NMC soils. This study is the first major bacterial sequencing effort of permafrost in the NMC and SJ wetlands, which provides fundamental data for further studies of microbial function in extreme ecosystems under climate change scenarios.

  1. Effects of the soil freeze-thaw process on the regional climate of the Tibet Plateau

    Science.gov (United States)

    Luo, S., Sr.; Chen, B.; Lu, S.; Zhang, Y.; Ma, D.

    2015-12-01

    Single-point and regional simulation experiments on the Tibet Plateau, both with and without consideration of the soil freeze-thaw process, were set up with CLM3.5 and RegCM4 models. Comparison of the simulated soil temperature and moisture, surface energy flux, and upper-lower atmospheric circulation showed that the regional climate can be influenced by the freeze-thaw process of soil. The results indicate that the freeze-thaw process is a buffer to the seasonal changes in soil and near-surface temperatures and strengthens the energy exchange between the soil and the atmosphere. During the freeze (thaw) process, releasing (absorbing) of phase change energy retards the cooling (heating) effect of air temperature on soil. The soil freeze-thaw process increases (decreases) the surface heat source of the plateau in winter (summer), which increases (decreases) the near-surface temperature in winter (summer). Promoted by atmospheric circulation, the soil freeze-thaw process influences climate at the high and low altitudes of the plateau; this may also contribute to the maintenance of the South Asia High. In the early stages of permafrost degradation, the regional climate effects of freezing and thawing may accelerate the degradation of permafrost.

  2. Earthquake focal parameters and lithospheric structure of the anatolian plateau from complete regional waveform modeling

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, A

    2000-12-28

    This is an informal report on preliminary efforts to investigate earthquake focal mechanisms and earth structure in the Anatolian (Turkish) Plateau. Seismic velocity structure of the crust and upper mantle and earthquake focal parameters for event in the Anatolian Plateau are estimated from complete regional waveforms. Focal mechanisms, depths and seismic moments of moderately large crustal events are inferred from long-period (40-100 seconds) waveforms and compared with focal parameters derived from global teleseismic data. Using shorter periods (10-100 seconds) we estimate the shear and compressional velocity structure of the crust and uppermost mantle. Results are broadly consistent with previous studies and imply relatively little crustal thickening beneath the central Anatolian Plateau. Crustal thickness is about 35 km in western Anatolia and greater than 40 km in eastern Anatolia, however the long regional paths require considerable averaging and limit resolution. Crustal velocities are lower than typical continental averages, and even lower than typical active orogens. The mantle P-wave velocity was fixed to 7.9 km/s, in accord with tomographic models. A high sub-Moho Poisson's Ratio of 0.29 was required to fit the Sn-Pn differential times. This is suggestive of high sub-Moho temperatures, high shear wave attenuation and possibly partial melt. The combination of relatively thin crust in a region of high topography and high mantle temperatures suggests that the mantle plays a substantial role in maintaining the elevation.

  3. Rapid regional surface uplift of the northern Altiplano plateau revealed by multiproxy paleoclimate reconstruction

    Science.gov (United States)

    Kar, Nandini; Garzione, Carmala N.; Jaramillo, Carlos; Shanahan, Timothy; Carlotto, Victor; Pullen, Alex; Moreno, Federico; Anderson, Veronica; Moreno, Enrique; Eiler, John

    2016-08-01

    The central Altiplano is inferred to have experienced ∼ 2.5 ± 1km surface uplift between ∼10 and 6 Ma, while the southern Altiplano experienced a similar magnitude of surface uplift that began earlier, between ∼16 and 9 Ma. To properly constrain the along strike timing of the Altiplano plateau surface uplift, it is necessary to know how and when the northernmost part of the Altiplano plateau evolved. We reconstruct the paleoclimate and infer the corresponding paleoelevation from the Miocene-Pliocene deposits of the Descanso-Yauri basin (14-15°S) in the northernmost part of the Altiplano plateau using 4 different proxies, including carbonate clumped isotope composition (i.e., Δ47 values), carbonate δ18Oc, leaf wax δDwax and pollen assemblages from paleosol, lacustrine and palustrine carbonates and organic-rich sediments. The isotopic signatures reflect past climate conditions of mean annual air temperature (Δ47) and meteoric water isotope values (δ18Oc, δDwax). Our results show that the northernmost plateau remained at low elevation (0.9 ± 0.8 to 2.1 ± 0.9km) until late Miocene time (∼9 Ma) characterized by ∼15 °C warmer than modern temperature (mean annual air temperature of 23 ± 4 °C, 2σ), low elevation vegetation and precipitation signature with reconstructed □ δ18Omw (VSMOW) of - 8.3 ± 2.0 ‰ (2 σ) from carbonate (δ18Oc) and - 8.6 ± 1.8 ‰ (2 σ) from leaf wax (δDwax). Modern elevations of 4 km were not reached until 5.4 ± 1.0Ma, as indicated by a negative shift in δDwax (VSMOW) from - 143.4 ± 12.8 ‰ (2 σ) to - 209.2 ± 21.1 ‰ (2 σ) between 9.1 ± 0.7 and 5.4 ± 1.0Ma. The timing of surface uplift of the northernmost Altiplano is consistent with the evidence for late Miocene surface uplift of the central Altiplano (16-19°S) between 10 and 6 Ma, and indicates that regional scale uplift in the northern-central plateau significantly postdates the onset of surface uplift in the southern Altiplano (19-22°S) between ∼16

  4. Ecosystem health assessment on the hill and gully area of Loess Plateau in Inner Mongolia,China

    Institute of Scientific and Technical Information of China (English)

    HUANG Heping; YANG Jie; SONG Bingyu; BAO Tiejun

    2006-01-01

    Maintenance of ecosystem health is the primary focus of a sound ecological restoration.Yet methods involved in quantifying and assessing the health level remain a challenge to the ecological community.In this study,we selected the hill and gully area of Loess Plateau,Inner Mongolia,China,as our study area.The soil and water erosions in this area continue to be responsible for many environmental problems in northern China because of its fragility and long disturbance history.In this study,we developed an assessment method of indicator system(AMIS)based on analytical hierarchy process(AHP),fuzzy mathematics.and the theory of net-hierarchy.At ecosystem or catchment scale,three sample areas,that is(1)intact vegetation(i.e., Aguimiao Natural Reserve,110°45'E,39°28'N),(2)reconstructed vegetation(Wufendigou Soil and Water Conservation Experimental Area,111°07'E 39°45'N),and (3)severely degraded vegetation(Yangquangou Catchment,111°06'E,39°45'N)in the hill and gully area of Loess Plateau in Inner Mongolia.China.were selected to examine ecosystem vigor,organizational structure,service function,and soil healm.We applied the AMIS for all three landscapes by categorizing each ecosystem into five health levels.Wle found that the health index for reconstructed vegetation were at levels of Ⅳ,Ⅱ,Ⅳ,and Ⅲ,while those of degraded vegetation were ranked at Ⅴ,Ⅳ,Ⅴ,and Ⅳ.Overall.the comprehensive ecosystem health index of reconstmcted vegetation was lower than that of intact vegetation but higher than that of degraded vegetation.The health index for reconstructed vegetation was at level Ⅲ.and that of degraded vegetation was still at level Ⅳ.The contributing values were:organization structure>soil health>vigor>service function.Based on our results and assessments,we proposed several management recommendations and methods for restoring the regional ecosystems.

  5. Regional characteristics of dust events in China

    Institute of Scientific and Technical Information of China (English)

    WANGShigong; WANGJinyan; ZHOUZijiang; SHANGKezheng; YANGDebao; ZHAO

    2003-01-01

    The regional characteristics of dust events in China has been mainly studied by using the data of dust storm,wind-blown sand and floating dust from 338 observation stations through China from 1954 to 2000.The results of this study are as follows:(1)In China,there are two high frequent areas of dust events,one is located in the area of Minfeng and Hotan in the South xinjiang Basin,the other is situated in the area of Minqin and Jilantai in the Hexi Region.Furthermore,the spatial distributions of the various types of dust events are different.The dust storms mainly occur in the arid and semiarid areas covering the deserts and the areas undergoing desertification in northern China.Wind-blown sand and floating-dust not only occur in the areas where dust storms occur,but also extend to the neighboring areas.The range of wind-blown sand extends northeastward and southeastward,but floating-dust mainly extends southeastward to the low-latitude region such as the East China Plain and the area of the middloe and lower reaches of the Yangtze River.Compared with wind-blown sand,the floating-dust seldom occurs in the high latitude areas such as North xinjiang and Northeast China.(2)The affected areas of dust storms can be divided into seven sub-regions,that is,North Xinjiang Region,South Xinjiang Region,Hexi Region,Qaidam Basin Region,Hetao Region.Northeastem China Region and Qinghai-Xizang (Tibet) Region.The area of the most frequent occurrence of dust storms and floating-dust is in South Xinjiang Region,and of wind-blown sang in the Hexi Region.In general,the frequency of dust events in all the seven regions shows a decreasing thendency from 1954 to 2000,but there are certain differences between various dust events in different regions.The maximum interannual change and ariance of dust events during this time happened in South Xinjiang Region and Hexi Region.The udst events generally occur most frequently in April in most parts of China.The spring occurred days of dust events

  6. Ethnobotanical Study of Medicinal Plants Used for the Treatment of Malaria in the Plateau Region, Togo.

    Science.gov (United States)

    Agbodeka, Kodjovi; Gbekley, Holaly E; Karou, Simplice D; Anani, Kokou; Agbonon, Amegnona; Tchacondo, Tchadjobo; Batawila, Komlan; Simpore, Jacques; Gbeassor, Messanvi

    2016-03-01

    In Togo, malaria constitutes a major public health problem but, until now, the population still mostly relies on herbal medicine for healing. This study aimed to document medicinal plants used for malaria therapy in the Plateau region of the country. Semi-structured questionnaire interviews were used to gather ethnobotanical and sociodemographic data from traditional healers of the study area. A total of 61 plants species belonging to 33 families were found to be in use for malaria therapy in the Plateau region. Caesalpiniaceae were the most represented family with 7 species, followed by Euphorbiaceae and Poaceae with 4 species each. According to the relative frequency of citation (RFC), Newbouldia laevis Seem. (RFC =0.52), Sarcocephalus latifolius (Sm.) E.A. Bruce (RFC =0.48), Acanthospermum hispidum DC. (RFC =0.43), and Senna siamea (Lam.) H.S. Irwin and Barneby (RFC =0.40) were the most cited in the treatment of malaria in the traditional medicine in the Plateau region. The parts of plants used could either be the barks, roots, leaves, or whole plants. The recipes also could be a combination of various species of plants or plant parts. This study highlights the potential sources for the development of new antimalarial drugs from indigenous medicinal plants found in the Plateau region of Togo. Such results could be a starting point for in vitro antimalarial screenings. 61 plants species from 33 families are use for malaria therapy in the Plateau region of TogoThe main families are Caesalpiniaceae Euphorbiaceae and PoaceaeThe most used species are Newbouldia laevis Seem. (RFC = 0.52), Sarcocephalus latifolius (Sm.) E.A. Bruce (RFC = 0.48), Acanthospermum hispidum DC. (RFC = 0.43), and Senna siamea (Lam.) H.S. Irwin and Barneby (RFC = 0.40) Abbreviations Used: RFC: Relative frequency of citation, FC: Frequency of citation, Dec: Decoction, Orl: Oral route, Mac: Maceration, Jui: Juice, Inf: Infusion, Sau: Sauce, Kne: Kneading, Le: Leaves, Rt: Roots, Wp: Whole plant

  7. Spatial-temporal patterns of water use efficiency and climate controls in China's Loess Plateau during 2000-2010.

    Science.gov (United States)

    Zhang, Tian; Peng, Jian; Liang, Wei; Yang, Yuting; Liu, Yanxu

    2016-09-15

    Accurate assessments of spatial-temporal variations in water use efficiency (WUE) are important for evaluation of carbon and water balances. In this study, the spatial and temporal patterns of WUE and associated climate controls in China's Loess Plateau are investigated over 2000-2010 by utilizing remote sensing data and multiple statistical methods; which provides a greater understanding about how WUE changed after the Grain to Green Program (GTGP) launched. Carbon sequestration (i.e., net primary productivity, NPP) is estimated with the CASA model and water consumption (i.e., evapotranspiration, ET) is obtained from the MODIS product (i.e., MOD16). Our results identify an increasing trend in the regional mean NPP that amounted to 7.593gC/m(2)·yr with an average value of 310.035gC/m(2)·yr. Changes in ET are segmented into three stages, the growth (2000-2003), decline (2004-2006) and stable (2007-2010) stages. Regional WUE is measured at 0.915gC/mm·m(2) and shows an upward trend at a rate of 0.027gC/mm·m(2)·yr. Spatially, significant regional heterogeneity is found in both NPP and WUE with gradients decreasing from the southeast to the northwest, but sharp rises detected in northern Shaanxi. At the biome level, the annual average WUE of the four groups decrease in the order of grasslands>woodlands>shrublands>croplands. Moreover, all biomes in the grassland ecosystems exhibit a growth in WUE as does the arid desert zone in the northwestern region, suggesting that vegetation in moderately water-deficient areas may have a higher tolerance to drought. Among different meteorological factors, precipitation and drought severity index (DSI) in the Loess Plateau show a latitudinal zonality and influences the WUE, which indicated that the moisture rather than temperature would be the major control factor of the regional WUE. Finally, significant variation in vegetation WUE sensitivity in response to meteorological factors is noted. Temperature is found to be the

  8. Effect of reducing the topographical altitude of the Tibetan Plateau on a severe winter drought in eastern China as determined using RAMS

    Science.gov (United States)

    Meng, Chunchun; Ma, Yaoming; Han, Cunbo; Gou, Peng

    2017-08-01

    Regional Atmospheric Modeling System (RAMS) was applied to the study of the effect of the topographical altitude of the Tibetan Plateau (TP) on a severe drought event which took place in eastern China from November 2008 to January 2009. Two simulations of this drought event were conducted: a control simulation (CNTRL run) using original model settings and a sensitive simulation (TOPO run), where no change other than to reduce the TP topography by 50 %. The results show that the CNTRL simulation validates RAMS by reproducing this drought event fairly accurately. However, as part of the TOPO simulation, the total heat flux showed a decrease over most parts of the TP, latent heat flux underwent a significant increase over the southeastern TP, contrary to sensible heat, and a universal decrease over eastern China; this led to an increase in precipitation over the southeastern TP and a decrease in precipitation over eastern China. The decrease of total heat flux over the TP is collocated with an anomalous anticyclonic circulation from the TP to the coasts of southeastern China. Changes in atmospheric circulation and low-level water vapor transport pathways were consistent with changes in precipitation. In general, reducing the topographical altitude of the TP worsens drought in eastern China and moreover causes a significant decrease in precipitation over southern China.

  9. Calcium Nodules as a Proxy for Quaternary Paleoclimate Change on China's Loess Plateau.

    Science.gov (United States)

    He, Wenming; He, Hongming; Zhu, Mingyong

    2015-01-01

    Different proxies have been used to investigate Quaternary paleoclimate change. Here, we used weathering of calcium nodules in paleosols on China's Loess Plateau as a proxy for Quaternary paleoclimate changes to provide an alternative indicator of these changes. Paleosol and carbonate nodules were collected from Luochuan and Lantian counties in Shaanxi Province, China. We found that this approach allowed quantitative reconstruction of temperature, rainfall, soil mineral composition, and the effects of weathering and leaching. The changes in carbonate content in the loess and paleosol sequences were controlled by alternating dry and wet climatic conditions. Nodule formation conditions were directly affected by the leaching and migration of elements. The loess and paleosol sequences developed calcium nodules, and their formation was closely related to the rainfall and leaching characteristics of the paleoclimate. The paleoclimate and soil minerals affected the vegetation types and directly influenced changes in the soil. During formation of the calcium nodules, the surface vegetation evolved slowly, and the number of species and quantity of vegetation both decreased.

  10. Impact of the Loess Plateau on the atmospheric boundary layer structure and air quality in the North China Plain: a case study.

    Science.gov (United States)

    Hu, Xiao-Ming; Ma, ZhiQiang; Lin, Weili; Zhang, Hongliang; Hu, Jianlin; Wang, Ying; Xu, Xiaobin; Fuentes, Jose D; Xue, Ming

    2014-11-15

    The North China Plain (NCP), to the east of the Loess Plateau, experiences severe regional air pollution. During the daytime in the summer, the Loess Plateau acts as an elevated heat source. The impacts of such a thermal effect on meteorological phenomena (e.g., waves, precipitation) in this region have been discussed. However, its impacts on the atmospheric boundary layer structure and air quality have not been reported. It is hypothesized that the thermal effect of the Plateau likely modulates the boundary layer structure and ambient concentrations of pollutants over the NCP under certain meteorological conditions. Thus, this study investigates such effect and its impacts using measurements and three-dimensional model simulations. It is found that in the presence of daytime westerly wind in the lower troposphere (~1 km above the NCP), warmer air above the Loess Plateau was transported over the NCP and imposed a thermal inversion above the mixed boundary layer, which acted as a lid and suppressed the mixed layer growth. As a result, pollutants accumulated in the shallow mixed layer and ozone was efficiently produced. The downward branch of the thermally-induced Mountain-Plains Solenoid circulation over the NCP contributed to enhancing the capping inversion and exacerbating air pollution. Previous studies have reported that low mixed layer, a factor for elevated pollution in the NCP, may be caused by aerosol scattering and absorption of solar radiation, frontal inversion, and large scale subsidence. The present study revealed a different mechanism (i.e., westerly warm advection) for the suppression of the mixed layer in summer NCP, which caused severe O3 pollution. This study has important implications for understanding the essential meteorological factors for pollution episodes in this region and forecasting these severe events.

  11. Biodiversity and conservation in the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Tibetan Plateau (Qinghai-Xizang Plateau) is a unique biogeographic region in the world, where various landscapes, altitudinal belts, alpine ecosystems, and endangered and endemic species have been developed. A total of 26 altitudinal belts, 28 spectra of altitudinal belts, 12,000 species of vascular plant, 5,000 species of epiphytes, 210 species of mammals, and 532 species of birds have been recorded. The plateau is also one of the centers of species formation and differentiation in the world. To protect the biodiversity of the plateau, about 80 nature reserves have been designated, of which 45 are national or provincial, covering about 22% of the plateau area. Most of the nature reserves are distributed in the southeastern plateau. Recently, the Chinese government has initiated the "Natural Forests Protection Project of China,' mainly in the upper reaches of the Yangtze and Yellow rivers. "No logging" policies have been made and implemented for these areas.

  12. China's Policymaking for Regional Economic Cooperation

    DEFF Research Database (Denmark)

    Jiang, Yang

    Yang Jiang opens the black box of China's policymaking for free trade agreements and key regional financial initiatives. Using first-hand interview data, she sheds light on the key trends of China's trade and financial politics after its WTO entry in 2001. In particular, she highlights...

  13. Analysis of the 2008 heavy snowfall over South China using GPS PWV measurements from the Tibetan Plateau

    Science.gov (United States)

    Xie, Y.; Wei, F.; Chen, G.; Zhang, T.; Hu, L.

    2010-06-01

    Four successive storms with freezing rain and snow blanketed South China from 10 January-2 February 2008, when the precipitation increased more than 200%-300% above the average for the corresponding period. The unusual atmospheric circulation associated with these disasters was caused by many complex physical processes, one of which was the active southern branch of currents over low latitude ocean areas which provided plenty of water vapor for South China. The ground-based GPS Precipitable Water Vapor (PWV) measurements on the Tibetan Plateau, supported by the China and Japan Intergovernmental Cooperation Program (JICA), has compensated for the lack of conventional observations of atmospheric water vapor in this area and provided a good opportunity to analyze the character of the water vapor transport in the four heavy precipitation processes. It was found that the GPS stations located on the southeastern Tibetan Plateau were on the route of the water vapor transport during 25 January-29 January and 31 January-2 February when two heavy precipitation events occurred over South China. The increasing trend from the one to two days pre-observation by the GPS stations was then associated with the heavy precipitation. Precipitation during 10 January-16 January and 18 January-22 January was significantly related to the abnormal variation of the one day pre-observation by the GPS stations located on the northeastern Tibetan Plateau. This research indicates that ground-based GPS measurements are applicable to data assimilation in operational numerical models.

  14. Analysis of the 2008 heavy snowfall over South China using GPS PWV measurements from the Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Y. [Texas A and M Univ., College Station, TX (United States). Dept. of Atmospheric Sciences; Wei, F.; Chen, G.; Zhang, T. [Chinese Academy of Meteorological Sciences, Beijing (China). State Key Lab. of Severe Weather; Hu, L. [Texas A and M Univ., College Station, TX (United States). Dept. of Oceanography

    2010-07-01

    Four successive storms with freezing rain and snow blanketed South China from 10 January-2 February 2008, when the precipitation increased more than 200%- 300% above the average for the corresponding period. The unusual atmospheric circulation associated with these disasters was caused by many complex physical processes, one of which was the active southern branch of currents over low latitude ocean areas which provided plenty of water vapor for South China. The ground-based GPS Precipitable Water Vapor (PWV) measurements on the Tibetan Plateau, supported by the China and Japan Intergovernmental Cooperation Program (JICA), has compensated for the lack of conventional observations of atmospheric water vapor in this area and provided a good opportunity to analyze the character of the water vapor transport in the four heavy precipitation processes. It was found that the GPS stations located on the southeastern Tibetan Plateau were on the route of the water vapor transport during 25 January-29 January and 31 January-2 February when two heavy precipitation events occurred over South China. The increasing trend from the one to two days pre-observation by the GPS stations was then associated with the heavy precipitation. Precipitation during 10 January-16 January and 18 January-22 January was significantly related to the abnormal variation of the one day preobservation by the GPS stations located on the northeastern Tibetan Plateau. This research indicates that ground-based GPS measurements are applicable to data assimilation in operational numerical models. (orig.)

  15. Analysis of the 2008 heavy snowfall over South China using GPS PWV measurements from the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Y. Xie

    2010-06-01

    Full Text Available Four successive storms with freezing rain and snow blanketed South China from 10 January–2 February 2008, when the precipitation increased more than 200%–300% above the average for the corresponding period. The unusual atmospheric circulation associated with these disasters was caused by many complex physical processes, one of which was the active southern branch of currents over low latitude ocean areas which provided plenty of water vapor for South China. The ground-based GPS Precipitable Water Vapor (PWV measurements on the Tibetan Plateau, supported by the China and Japan Intergovernmental Cooperation Program (JICA, has compensated for the lack of conventional observations of atmospheric water vapor in this area and provided a good opportunity to analyze the character of the water vapor transport in the four heavy precipitation processes. It was found that the GPS stations located on the southeastern Tibetan Plateau were on the route of the water vapor transport during 25 January–29 January and 31 January–2 February when two heavy precipitation events occurred over South China. The increasing trend from the one to two days pre-observation by the GPS stations was then associated with the heavy precipitation. Precipitation during 10 January–16 January and 18 January–22 January was significantly related to the abnormal variation of the one day pre-observation by the GPS stations located on the northeastern Tibetan Plateau. This research indicates that ground-based GPS measurements are applicable to data assimilation in operational numerical models.

  16. Impact of the Anomalous Thawing in the Tibetan Plateau on Summer Precipitation in China and Its Mechanism

    Institute of Scientific and Technical Information of China (English)

    GAO Rong; WEI Zhigang; DONG Wenjie; ZHONG Hailing

    2005-01-01

    The impact of the anomalous thawing of frozen soil in the late spring on the summer precipitation in China and its possible mechanism are analyzed in the context of the frozen soil thawing date data of the 50meteorological stations in the Tibetan Plateau, and the NCEP/NCAR monthly average reanalysis data.Results show that the thawing dates of the Tibetan Plateau gradually become earlier from 1980 to 1999,which is consistent with the trend of global warming in the 20th century. Because differences in the thermal capacity and conductivity between frozen and unfrozen soils are larger, changes in the freezing/thawing process of soil may change the physical properties of the underlying surface, thus affecting exchanges of sensible and latent heat between the ground surface and air. The thermal state change of the plateau ground surface must lead to the thermal anomalies of the atmosphere over and around the plateau, and then further to the anomalies of the general atmospheric circulation. A possible mechanism for the impact of the thawing of the plateau on summer (July) precipitation may be as follows. When the frozen soil thaws early (late) in the plateau, the thermal capacity of the ground surface is large (small), and the thermal conductivity is small (large), therefore, the thermal exchanges between the ground surface and the air are weak (strong). The small (large) ground surface sensible and latent heat fluxes lead to a weak (strong) South Asian high, a weak (strong) West Pacific subtropical high and a little to south (north) of its normal position. Correspondingly, the ascending motion is strengthened (weakened) and precipitation increases (decreases) in South China, while in the middle and lower reaches of the Changjiang River, the ascending motion and precipitation show the opposite trend.

  17. Assessing the effects of changes in land use and climate on runoff and sediment yields from a watershed in the Loess Plateau of China.

    Science.gov (United States)

    Zuo, Depeng; Xu, Zongxue; Yao, Wenyi; Jin, Shuangyan; Xiao, Peiqing; Ran, Dachuan

    2016-02-15

    The changes in runoff and sediment load in the Loess Plateau of China have received considerable attention owing to their dramatic decline during recent decades. In this paper, the impacts of land-use and climate changes on water and sediment yields in the Huangfuchuan River basin (HFCRB) of the Loess Plateau are investigated by combined usage of statistical tests, hydrological modeling, and land-use maps. The temporal trends and abrupt changes in runoff and sediment loads during 1954-2012 are detected by using non-parametric Mann-Kendall and Pettitt tests. The land-use changes between 1980 and 2005 are determined by using transition matrix analysis, and the effects of land-use and climate changes on water and sediment yields are assessed by using the Soil and Water Assessment Tool (SWAT) hydrological model and four scenarios, respectively. The results show significant decreasing trends in both annual runoff and sediment loads, whereas slightly decreasing and significantly increasing trends are detected for annual precipitation and air temperature, respectively. 1984 is identified as the dividing year of the study period. The land-use changes between 1980 and 2005 show significant effects of the Grain for Green Project in China. Both land-use change and climate change have greater impact on the reduction of sediment yield than that of water. Water and sediment yields in the upstream region show more significant decreases than those in the downstream region under different effects. The results obtained in this study can provide useful information for water resource planning and management as well as soil and water conservation in the Loess Plateau region.

  18. Rise and Demise of a Southern Laramide Hinterland Plateau, US-Mexico Border Region

    Science.gov (United States)

    Lawton, T. F.; Clinkscales, C. A.; Jennings, G. R.

    2011-12-01

    New U-Pb geochronology and stratigraphic data sets suggest that an elevated, altiplano-like plateau existed in the backarc region of what is now southern Arizona and southern New Mexico during Late Cretaceous through Paleogene (~28 Ma) time, and indicate that the Laramide province of the US was thus flanked on both its western and southern sides by hinterland plateaus. The Laramide stratigraphic record of southwestern New Mexico and southeastern Arizona formed during a short time period spanning 75-70 Ma, as indicated by numerous, newly-dated, interbedded tuff beds. The Laramide deposits (Fort Crittenden Formation of Arizona, Ringbone and Skunk Ranch Formations of Arizona, Cabullona Group of Sonora), which contain growth strata developed adjacent to steep thrust faults, accumulated in lake and lake-margin fan-delta and alluvial-fan settings on the northern margin of a volcanic arc whose main magmatic locus lay in northeastern Sonora and northwestern Chihuahua. By the end of basin development, the arc had migrated northward to occupy the former depocenters, such that intermediate volcanic rocks interfinger with and overlie the lacustrine deposits, and subvolcanic plutons, one with an age of 69 Ma, intrude and cross-cut thrust faults. Laramide strata unconformably overlie lowermost Upper Cretaceous (~97 Ma) strata and contractional structures are unconformably truncated beneath Oligocene (~33 Ma) volcaniclastic rocks. Detritus derived from the Cretaceous arc is abundant in Campanian fluvial strata (Kaiparowits Formation and Mesaverde Group) of the southern Colorado Plateau. East-west normal faults with as much as 3 km of displacement and a related array of conjugate NW- and NE-striking normal faults, many of these previously interpreted as reverse and transcurrent faults, are widespread in ranges of southern New Mexico and southeastern Arizona. These faults post-date Laramide contractional structures and are in turn cut by Neogene N-S normal faults. The east

  19. Regional chemical setting of the Apollo 16 landing site and the importance of the Kant Plateau

    Science.gov (United States)

    Andre, C. G.; El-Baz, F.

    1982-01-01

    Orbital X-ray data from the Apollo 16 region indicate that physiographic units identified before the lunar mission can be classified as chemical units as well. The Descartes Mountains, however, appear to be an extension of the Kant Plateau composition that is unusually anorthositic and resembles farside terra. The Cayley Plains have closer affinities to basaltic materials than terra materials, physically, spectrally and chemically. The Theophilus impact, 330 km east of the landing site, excavated magnesium-rich basalts from below less-magnesian flows in Mare Nectaris; but, mafic ejecta was substantially blocked from the Apollo 16 site by the Kant Plateau that rises 5 km above the level of the mare. Apollo 16 soil samples from stations selected to collect either Descartes Mountains material or Cayley Plains material were surprisingly similar. However, they do, indeed, show the chemical trends indicative of the two units as defined by the orbiting geochemistry detectors. The Kant Plateau and Descartes Mountains material may be among the rare nearside examples of a plagioclase-rich cumulate of the primordial magma ocean.

  20. Winter soil CO2 efflux in two contrasting forest ecosystems on the eastern Tibetan Plateau, China

    Institute of Scientific and Technical Information of China (English)

    Zhenfeng Xu; Feifei Zhou; Huajun Yin; Qing Liu

    2015-01-01

    Significant CO2 fluxes from snow-covered soils occur in cold biomes. However, little is known about winter soil respiration on the eastern Tibetan Plateau of China. We therefore measured winter soil CO2 fluxes and estimated annual soil respiration in two contrasting coniferous forest ecosystems (a Picea asperata plantation and a natural forest). Mean winter soil CO2 effluxes were 1.08 lmol m-2 s-1 in the plantation and 1.16 lmol m-2 s-1 in the natural forest. These values are higher than most reported winter soil CO2 efflux values for temperate or boreal forest ecosystems. Winter soil respiration rates were similar for our two forest ecosystems but mean soil CO2 efflux over the growing season was higher in the natural forest than in the plantation. The estimated winter and annual soil effluxes for the natural forest were 176.3 and 1070.3 g m-2, respectively, based on the relationship between soil respiration and soil temperature, which were 17.2 and 9.7 % greater than their counterparts in the plantation. The contributions of winter soil respiration to annual soil efflux were 15.4 % for the plantation and 16.5 % for the natural forest and were statistically similar. Our results indicate that winter soil CO2 efflux from frozen soils in the alpine coniferous forest ecosystems of the eastern Tibetan Plateau was considerable and was an important component of annual soil respiration. Moreover, reforestation (natural coniferous forests were deforested and reforested with P. asperata plantation) may reduce soil respiration by reducing soil carbon substrate availability and input.

  1. A Younger Dryas plateau icefield in the Monadhliath, Scotland, and implications for regional palaeoclimate

    Science.gov (United States)

    Boston, Clare M.; Lukas, Sven; Carr, Simon J.

    2015-01-01

    A record of Younger Dryas glaciation in Scotland is well established. However, the role of the Monadhliath, a significant plateau area extending over 840 km2 in central Scotland, has never been investigated systematically. We present the first systematic glacial geomorphological mapping across the whole region, which has led to the identification of hitherto-unrecorded glacial and associated landforms. The spatial distribution of these landforms indicates that the last phase of glaciation in the area was that of a local plateau icefield. In addition, a clear morphostratigraphical signature provides a strong indication that the icefield dates to the Younger Dryas (12.9-11.7 ka), which is supported by numerical ages in the southeast of the study area. Based on the geomorphological evidence and 2D glacier surface profile modelling, a 280 km2 icefield is reconstructed. A novel approach is introduced to quantify plateau icefield thickness for equilibrium line altitude (ELA) and palaeoprecipitation calculations, resulting in greater overall data confidence compared to traditional reconstruction methods. The ELA for the whole icefield is calculated to be 714 ± 25 m, whilst the ELAs of individual outlet glaciers range from 560 m in the west to 816 m in the east, demonstrating a significant W-E precipitation gradient across the region during the Younger Dryas. These ELAs compare well with those calculated for Younger Dryas ice masses reconstructed in neighbouring regions and are in good agreement with overall precipitation patterns suggested for Scotland during this time. Whilst the total amount of precipitation calculated from these ELAs is highly dependent on the method used, irrespective of this, the study suggests a more arid Younger Dryas climate in the region compared to the present day.

  2. Uranium Potential and Regional Metallogeny in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jindai; LI Ziying

    2008-01-01

    This paper is briefly involved in distributions of China's uranium metallogenic types,provinces, regions and belts. Eight target regions have been pointed out to be worthy of prospectingfor uranium resources. The regional uranium metallogeny is discussed and great uranium potentialpointed out from many aspects. Generally speaking, there are favorable conditions for uraniummineralization and good perspective to explore for uranium resources.

  3. Regional competitiveness: The case of Western China

    Directory of Open Access Journals (Sweden)

    Vuković Darko

    2010-01-01

    Full Text Available This paper explains the concept of regional competitiveness and the factors that influence on it. A large number of various authors explain this concept, based on its different aspects, including: productivity, mikroaspekts (firm, quality of human capital, innovation, technology, infrastructure, social capital, etc.. Taking into account complex nature of regional competitiveness, it is difficult to determine a standard definition of this term. The second part of this paper refers to the case of western China. Substantial disparity in regional development is a reality in every geographically large country, and the causes of the disparity are numerous and complex. Regional inequality has been an important issue in China. This paper generally summarized China's Western regions geography, government policies and development situation. The authors put forward some practical strategies on how to help the western regions create a favorable environment to attract national and international investment.

  4. Evidence for cold events in the early Holocene from the Guliya ice core, Tibetan Plateau, China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Evidence for the "8.2 ka cold event" has been provided mostly from the circum-North Atlantic area. However, whether this cold event occurred in other places is a key to understanding its cause. Here, we provide the evidence for the "8.2 ka cold event" from the Guliya ice core in the northwest Tibetan Plateau, and it was found that the peak cooling (~8.3-8.2 ka) in this ice core was about 7.8-10℃, which was larger than the cooling in the North Atlantic region. The primary causes for this episode were diminished solar activity and weakened thermohaline circulation. Moreover, another weak cold event, centered about 9.4 ka, was also recorded in the Guliya ice core record. These two cold events were concurrent with the ice-rafting episodes in the North Atlantic during the early Holocene, which implies that the millennial-scale climatic cyclicity might exist in the Tibetan Plateau as well as in the North Atlantic.

  5. Response of surface processes to climatic change in the dunefields and Loess Plateau of North China during the late Quaternary

    Science.gov (United States)

    Lu, H.; Mason, J.A.; Stevens, T.; Zhou, Y.; Yi, S.; Miao, X.

    2011-01-01

    This paper draws on recent optically stimulated luminescence (OSL) dating to evaluate the long-held assumption that dust accumulation rates in the Loess Plateau and the extent of active aeolian sand in the dunefields to the north have varied together over time, because both are controlled by the strength of the Asian monsoons and also possibly because the dunefields are proximal loess sources. The results show there is little evidence that high rates of loess accumulation coincided with well-dated episodes of extensive dune activity in the Mu Us, Otindag, and Horqin dunefields, at 11-8ka and 1-0ka. Explanations for the apparent lack of coupling include local variation in the trapping of dust and post-depositional preservation of the loess and dune sediments, in response to varying local environmental conditions. In addition, a substantial portion of the loess may be transported directly from source areas where dust emission has somewhat different climatic and geomorphic controls than aeolian sand activity within the dunefields. The results of this study cast doubt on the use of loess accumulation rate as a palaeoclimatic proxy at millennial timescale. The dunefield and loess stratigraphic records are interpreted as primarily recording changes in effective moisture at a local scale, but the timing of late Quaternary dune activity, along with a variety of other evidence, indicates that moisture changes in many of the drylands of northern China may not be in phase with precipitation in core regions of the Asian monsoons. ?? 2011 John Wiley & Sons, Ltd.

  6. Evaluating sustainability of cropland use in Yuanzhou county of the Loess plateau, China using an emergy-based ecological footprint.

    Science.gov (United States)

    Bai, Xiaomei; Wen, Zhongming; An, Shaoshan; Li, Bicheng

    2015-01-01

    Evaluating the sustainability of cropland use is essential for guaranteeing a secure food supply and accomplishing agriculture sustainable development. This study was conducted in the ecologically vulnerable Loess Plateau region of China to evaluate the sustainability of cropland use based on an ecological footprint model that integrates emergy analysis. One modified method proposed in 2005 is known as the emergetic ecological footprint (EEF). We enhanced the method by accounting for both the surface soil energy in the carrying capacity calculation and the net topsoil loss for human consumption in the EF calculation. This paper evaluates whether the cropland of the study area was overloaded or sustainably managed during the period from 1981 to 2009. Toward this end, the final results obtained from EEF were compared to conventional EF and previous methods. The results showed that the cropland of Yuanzhou County has not been used sustainably since 1983, and the conventional EF analysis provided similar results. In contrast, a deficit did not appear during this time period when previous calculation methods of others were used. Additionally, the ecological sustainable index (ESI) from three models indicated that the recently used cropland system is unlikely to be unsustainable.

  7. Evaluating sustainability of cropland use in Yuanzhou county of the Loess plateau, China using an emergy-based ecological footprint.

    Directory of Open Access Journals (Sweden)

    Xiaomei Bai

    Full Text Available Evaluating the sustainability of cropland use is essential for guaranteeing a secure food supply and accomplishing agriculture sustainable development. This study was conducted in the ecologically vulnerable Loess Plateau region of China to evaluate the sustainability of cropland use based on an ecological footprint model that integrates emergy analysis. One modified method proposed in 2005 is known as the emergetic ecological footprint (EEF. We enhanced the method by accounting for both the surface soil energy in the carrying capacity calculation and the net topsoil loss for human consumption in the EF calculation. This paper evaluates whether the cropland of the study area was overloaded or sustainably managed during the period from 1981 to 2009. Toward this end, the final results obtained from EEF were compared to conventional EF and previous methods. The results showed that the cropland of Yuanzhou County has not been used sustainably since 1983, and the conventional EF analysis provided similar results. In contrast, a deficit did not appear during this time period when previous calculation methods of others were used. Additionally, the ecological sustainable index (ESI from three models indicated that the recently used cropland system is unlikely to be unsustainable.

  8. Teleseismic tomography of the southern Puna plateau in Argentina and adjacent regions

    Science.gov (United States)

    Bianchi, M.; Heit, B.; Jakovlev, A.; Yuan, X.; Kay, S. M.; Sandvol, E.; Alonso, R. N.; Coira, B.; Brown, L.; Kind, R.; Comte, D.

    2013-02-01

    We performed a teleseismic P wave tomography study using seismic events at both teleseismic and regional distances, recorded by a temporary seismic array in the Argentine Puna Plateau and adjacent regions. The tomographic images show the presence of a number of positive and negative anomalies in a depth range of 20-300 km beneath the array. The most prominent of these anomalies corresponds to a low-velocity body, located in the crust, most clearly seen in the center of the array (27°S, 67°W) between the Cerro Peinado volcano, the Cerro Blanco caldera and the Farallon Negro in the east. This anomaly (southern Puna Magmatic Body) extends from the northern most part of the array and follows the line with the highest density of stations towards the south where it becomes smaller. It is flanked by high velocities on the west and the east respectively. On the west, the high velocities might be related to the subducted Nazca plate. On the northeast the high velocity block coincides with the position of the Hombre Muerto basin in the crust and could be indicating an area of lithospheric delamination where we detected a high velocity block at 100 km depth on the eastern border of the Puna plateau, north of Galan. This block might be related to a delamination event in an area with a thick crust of Paleozoic metamorphic rocks at the border between Puna and Eastern Cordillera. In the center of the array the Southern Puna magmatic body is also flanked by high velocities but the most prominent region is located on the east and is interpreted as part of the Sierras Pampeanas lithosphere with high velocities. The position of the Sierras Pampeanas geological province is key in this area as it appears to limit the extension of the plateau towards the south.

  9. Numerical simulation of groundwater flow in the Columbia Plateau Regional Aquifer System, Idaho, Oregon, and Washington

    Science.gov (United States)

    Ely, D. Matthew; Burns, Erick R.; Morgan, David S.; Vaccaro, John J.

    2014-01-01

    A three-dimensional numerical model of groundwater flow was constructed for the Columbia Plateau Regional Aquifer System (CPRAS), Idaho, Oregon, and Washington, to evaluate and test the conceptual model of the system and to evaluate groundwater availability. The model described in this report can be used as a tool by water-resource managers and other stakeholders to quantitatively evaluate proposed alternative management strategies and assess the long‑term availability of groundwater. The numerical simulation of groundwater flow in the CPRAS was completed with support from the Groundwater Resources Program of the U.S. Geological Survey Office of Groundwater.

  10. The Distribution of DEN Infected People in Dushan and Xingyi Area of Yunnan-Guizhou Plateau, China

    Institute of Scientific and Technical Information of China (English)

    Wei Liu; Li Zuo; Yongbing Zhou

    2006-01-01

    The dengue viruses (DEN, genus Flavivirus, family Flaviviridae) are mosquito borne and have caused 100 million cases of dengue fever each year in most tropical and subtropical areas of the world. However, in the Southwest area of Yunnan-Guizhou Plateau, China, the previous work demonstrated that different geographic strains of Aedes albopictus were susceptible to dengue virus. In this study, we collected 456 sera samples from patients with fever and 994 sera samples from healthy population in Dushan and Xingyi area of Yunnan-Guizhou Plateau, China. All sera samples were tested for dengue IgG by enzyme-linked immunosorbent assay (ELISA). Patients' sera samples were tested for dengue IgM and DEN antigen was checked in the sera of 6 from 456 samples with which C6/36 cell in culated by IFA. The results indicate that these patients with fever were infected with DEN-2 and suggest that DEN infection had existed in Dushan and Xingyi area of Yunnan-Guizhou Plateau, China.

  11. Regional Convergence and Sustainable Development in China

    Directory of Open Access Journals (Sweden)

    Fang Yang

    2016-01-01

    Full Text Available Based on the convergence theory of economic growth, this paper extends this concept to the human development index and carries out an empirical analysis of regional development in China between 1997 and 2006. Our research shows that the conditional convergence has been identified. Investment in fixed assets, government expenditure on education, health and infrastructure construction have positive effects on regional convergence of social development. Population weighted analysis of human development index provides support for weak convergence amongst provinces. Analysis of dynamics of regional distribution reveals the club convergence, which indicate two different convergence states. Central China is in the shade and lags behind, giving rise to the so-called “central downfall”. To solve this problem, the “Rise of Central China” Plan is necessary to promote the connection between coastal and inland regions of China and reduce the regional development gap.

  12. Soil water characteristic of a dense jujube plantation in the semi-arid hilly Regions of the Loess Plateau in China%黄土高原半干旱区山地密植枣林土壤水分特性研究

    Institute of Scientific and Technical Information of China (English)

    汪星; 周玉红; 汪有科; 卫新东; 郭旭新; 朱德兰

    2015-01-01

    针对陕北黄土丘陵区近年来形成的大规模枣林土壤水分研究薄弱的问题,本研究采用中子仪定位观测方法,探讨了山地密植枣林0~1000 cm土层范围的土壤水分特征变化规律。研究将黄土丘陵半干旱区的密植枣林土壤水分划分为活跃层、难恢复层和稳定层。活跃层是土壤0~200 cm土层,该层土壤水分具有明显的逐月动态变化规律,在枣树生育期内,5月是活跃层,土壤水分最干燥期,7月是土壤水分提升最明显期,10月是土壤水分最高期。土壤水分提升规律和枣树耗水规律一致,即在枣树生长旺盛时期,正是土壤水分提升最快的阶段;在枣树休眠结束和开始萌芽时枣林土壤水分出现最低值。枣林土壤水分难恢复层在200 cm以下,其深度取决于枣林年龄,林龄越大该层次越深,12年生密植枣林土壤耗水深度达到540 cm,其中难恢复层厚度为340 cm。难恢复层之下是土壤水分稳定层。研究认为密植枣林土壤耗水深度小于以往研究的刺槐、柠条和苜蓿等土壤水分消耗深度,山地密植枣林模式对今后研究人工林调控土壤水分有积极意义。%Jujube (Ziziphus jujube Mill. CV. Lizao) is an economically important tree fruit species cultivated in the semi-arid hilly regions of the loess plateau in China. A few studies focused on reporting soil water for this area;so this study aimed to quantify soil water characteristic within 0-1000 cm for dense jujube plantation, using the soil core method and neutron probe. The results showed that:(1) According to soil water dynamic change,the whole soil water profile was stratified into three layers:active layer,difficult re⁃covery layer,and stable layer. (2)The active layer ranged in the 0-200 cm;Soil water of this layer had ob⁃vious monthly dynamic change;In May, soil water content was the lowest during the whole growth stage (from May to October);soil water content

  13. The Effect of Integrated Grasses in Controlling Soil, Nutrient and Organic Matter in Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    Honest Augustine Mosha

    2013-01-01

    Full Text Available Soil and nutrient loss is one of a serious problem in Loess plateau china. The eroded materials are directly transported to the lakes and rivers specifically yellow river in China, this might lead to eutrophication if no prevention measures will be taken. The experiment was conducted on soil, and nutrient loss from 5º slope. Individual grasses plots for rye grass(Lolium, white clover(Trifolium repens and integrated grass (rye + white clover plots were prepared with a percentage cover of 25, 50, 80 and 100 in each treatment. Bare land was used as a reference plot. The results show that, the sediment loss in a bare land reported to be 1.5, 3, 2.7 and 1.3, 2.1, 1.9 in 100 % and 80 % cover plots. The runoff rate as compared to bare land, shown to be about 2 times less for white clover and rye grass plots, while more than 2 times less for integrated grasses plots. The total nitrogen and organic matter loss the results were in the order bare land white clover rye grasses and integrated grasses in which 100 %, 80 % and 50 % vegetative cover shown to perform better. On average enrichment ratio range was 40 % to 90 % for nutrient loss, and 50 % to 85 % for organic matter for all plots in comparison with soil origin. The enrichment ration significantly shown to be high from bare land> rye and white clover plots> integrated grasses plot. It has been concluded that integrated grasses is more effective measure over others in controlling both soil, nutrient and organic matter loss in the soil. This study contributed some information on the erosion modeling and improvement of soil and grassland conservation techniques for better land use for sustainable development

  14. Soil Insect Diversity and Abundance Following Different Fertilizer Treatments on the Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    LIN Ying-hua; LU Ping; YANG Xue-yun; ZHANG Fu-dao

    2013-01-01

    The presence of abundant and diverse communities of macro-arthropods is considered an indicator of sustainability in agroecosystems. This study was designed to investigate the effects of different fertilizer treatments on abundance and diversity of insects of arable loess soil on the Loess Plateau of China. These regimes included a control with no fertilizer addition or manure, treatments with application of mineral fertilizers (N, NK, NP, PK, NPK), treatments with NPK in combination with organic materials such as wheat straw or maize stalk, treatments with two rates of organic manure application;and different crop rotations (Rot.1:winter wheat summer maize;Rot.2:winter wheat summer maize soybean intercropping;and Rot.3:winter wheat or rapeseed summer maize soybean intercropping). Soil macro-arthropods were collected from the plough layer (0-20 cm) and sorted by hand after each harvest in June and October 2001 and 2002. A total of 3 132 individuals were collected, from 7 orders and 55 families, dominated by Formicidae (61.72%) and Staphylinidae (14.24%). The results showed that individuals and groups were significantly influenced by sampling dates, while groups were significantly influenced by the fertilization treatments. Soil insect biodiversity, as determined by the Shannon index, was significantly influenced by fertilization and sampling dates. The abundance of soil insects was positively and significantly correlated with soil moisture content in October 2002. Nitrogen, phosphorus and potassium fertilizers and incorporation of organic materials were favorable factors for abundance and diversity in arable loess soil.

  15. Analysis of Precipitation Characteristics during 1957-2012 in the Semi-Arid Loess Plateau, China.

    Science.gov (United States)

    Zhao, Weijun; Yu, Xinyang; Ma, Huan; Zhu, Qingke; Zhang, Yan; Qin, Wei; Ai, Ning; Wang, Yu

    2015-01-01

    Precipitation is the only water supply and most important factor affecting vegetation growth on the slopes of semi-arid Loess Plateau of China. Based on precipitation data from 7 synoptic stations in the study area over the period 1957-2012, the trends of precipitation and standardized precipitation index (SPI) were analyzed by using linear regression, Mann-Kendall, and Spearman's Rho tests at the 5% significance level. The results show that (1) the precipitation fluctuation of monthly precipitation was intense (coefficients of variation> 100%), and the drier years were recorded as 1965 and 1995 at all stations. (2) The significant change trend of different stations varied on different time scales: the Changwu station had a significant decreasing trend in April (-0.488 mm/year) and November (-0.249 mm/year), while Luochuan station was in April (-0.457 mm/year); Changwu station displayed a significant increasing trends in winter (0.220 mm/year) and a significant decreasing trends in spring (-0.770 mm/year). The significant decreasing trends in annual precipitation were detected at the Suide (-2.034 mm/year) and Yan'an (-2.129 mm/year) stations. (3) The SPI-12 series analysis suggests that the drought degree of Yulin and Changwu was the lowest and that of Hengshan was the highest among the 7 synoptic stations.

  16. Land use and land cover change processes in China's eastern Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    JinChang Li; HaiXia Liu; Yong Liu; ZhiZhu Su; ZiQiang Du

    2015-01-01

    Using Landsat remote sensing images, we analyzed changes in each land use type and transitions among different land use types during land use and land cover change (LUCC) in Ningwu County, located in the eastern Loess Plateau of China, from 1990 to 2010. We found that grassland, woodland, and farmland were the main land use types in the study area, and the area of each type changed slightly from 1990 to 2010, whereas the area of water, construction land, and unused land increased greatly. For the whole area, the net change and total change were insignificant due to weak human activity intensity in most of the study area, and the LUCC was dominated by quasi-balanced two-way transitions from 1990 to 2010. The insignificant overall amount of LUCC appears to have resulted from offsetting of rapid increases in population, economic growth, and the im-plementation of a program to return farmland to woodland and grassland in 2000. This program converted more farmland into woodland and grassland from 2000 to 2010 than from 1990 to 2000, but reclamation of woodland and grassland for use as farmland continued from 2000 to 2010, and is a cause for concern to the local government.

  17. Weed inhibition by sowing legume species in early succession of abandoned fields on Loess Plateau, China

    Science.gov (United States)

    Li, Jin-Hua; Xu, Dang-Hui; Wang, Gang

    2008-01-01

    A major constraint on vegetation succession on abandoned land is dominance by early successional species. Our aim was to inhibit weeds and alter the initial vegetation succession by the introduction of legume species ( Medicago sativa, Melilotus suaveolens, and Astragalus adsurgens) into abandoned fields on the Loess Plateau, China. Results from our study showed that the addition of legume species strongly affected the dominance pattern of the abandoned-field vegetation. The number of naturally colonizing species was inhibited by the introduction of legume species in the first two growing seasons. The strongest effect on weed inhibition appeared by sowing Melilotus suaveolens. Vegetation cover and above-ground biomass increased after introduction of legume species and the number of naturally colonizing plant species showed a positive correlation with above-ground biomass. Later successional species like Stipa breviflora and Astragalus polycladus appeared three years following the introduction of Melilotus suaveolens, indicating that the course of old-field succession may be accelerated by introducing legume species such as Melilotus suaveolens, at least temporarily.

  18. [Grain effect of landscape pattern indices in a gully catchment of Loess Plateau, China].

    Science.gov (United States)

    Qiu, Yang; Yang, Lei; Wang, Jun; Zhang, Ying; Meng, Qing-hua; Zhang, Xiao-guang

    2010-05-01

    By using landscape pattern analysis based on GIS, this paper studied the grain effect of landscape pattern indices with a scale 1-50 m in a gully catchment of the Loess Plateau, China from 1975 to 2007. In the catchment, the grain effect was obvious, and differed significantly with year. The grain effect had five types, i.e., stable, stable decreasing, undulatory decreasing, amplitude-accreting, and anomalistic changing. With increasing grain, the stable grain effect showed a stable patch richness density, the stable decreasing grain effect showed a decreasing trend of total edge, edge density, landscape shape index, aggregation index, and contagion index, the undulatory decreasing grain effect showed an undulatory decreasing trend of perimeter-area fractal dimension, the amplitude-accreting grain effect showed an amplitude increasing trend of total area, Shannon's diversity index, and evenness index, and the anomalistic changing grain effect showed an anomalistic change of patch number, patch density, mean patch area, largest patch index, splitting index, and landscape division index. In 1975, the grain effect of all the indices differed significantly from that in other years, and even, was in opposite.

  19. Characterization of dissolved organic matter fractions from Lake Hongfeng, Southwestern China Plateau

    Institute of Scientific and Technical Information of China (English)

    WANG Liying; WU Fengchang; ZHANG Runyu; LI Wen; LIAO Haiqing

    2009-01-01

    With XAD-series and ion exchange resins, dissolved organic matter (DOM) from Lake Hongfeng in Southwestern China Plateau was isolated into 6 fractions, i.e., humic acid (HA), fulvic acid (FA), hydrophobic neutrals (HON), hydrophilic acids (HIA), hydrophilic bases (HIB) and hydrophilic neutrals (HIN). Those fractions were characterized by high performance size exclusion chromatography, fluorescence spectroscopy and UV absorbance. Among the 6 fractions, FA was predominant and accounted for 51% of the total DOM. The hydrophobic fractions had larger molecular weight (1688--2355 Da) than hydrophilic fractions (1338--1928 Da). A strong correlation was observed between specific UV absorbance at 280 nm, E2/E3 (absorbance at 250 nm to 365 nm), and the molecular weight for DOM fractions. UV-Vis fulvic-like fluorescence peaks were found in all fractions. Protein-like fluorescence peaks existed in HON may indicate that microbial activity was severely in Lake Hongfeng. There was a significant relationship between fluorescence intensities and specific UV absorbance at 254 nm for those DOM fractions, suggesting their similar luminescence characteristics. The values of fluorescence index (?450/500) indicated that hydrophobic fractions may derive from terrestrial sources, in contrast to the hydrophilic fractions from microbial and terrestrial origins. Those results suggest that there were inter-relationships between molecular weight, fluorescence and absorbance characteristics, and also subtle consistencies between the hydrophilic and hydrophobic properties and sources for the 6 fractions from Lake Hongfeng.

  20. Land degradation, government subsidy, and smallholders' conservation decision: the case of the loess plateau in China

    Institute of Scientific and Technical Information of China (English)

    石敏俊; CHENKevin

    2004-01-01

    Land degradation is one of the severe environmental problems in China. In order to combat land degradation, a soil conservation program was introduced since 2000 to reduce soil erosion by converting slope-cultivated land into forestry and pasture. This paper represents the first systematic attempt to investigate the impact of the soil conservation program on land degradation in the loess plateau. The results indicate that the soil conservation program to convert slope fields into forest or pasture is an effective way to combat soil erosion. However, a subsidy that is higher than profit of land use activity of slope fields before their conversion into forest and pasture is needed to encourage farmers to join the conservation program. A policy measure to encourage and assist farmers to develop sedentary livestock by using crops produced from fields as well as fodder and forage grass from the converted slope fields might contribute to combat soil erosion. Increase in off-farm job opportunities may encourage households to reduce cultivation in slope fields. That implies a policy measure to encourage rural urbanization might contribute to combat soil erosion.

  1. Reduced Runoff Due to Anthropogenic Intervention in the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    Yanzhong Li

    2016-10-01

    Full Text Available To maintain the sustainable utilization of water resources and reduce soil erosion in the Loess Plateau, the Chinese government has adopted a number of environmental restoration strategies since 1999, including the Grain for Green Project (GFGP and the Natural Forest Conservation Program; these large projects greatly alter the regional water cycle. Detecting runoff changes and quantitatively assessing the contribution of anthropogenic activities (including land use/cover change (LUCC and water diversion and climate change (including potential evaporation and precipitation are imperative for implementing sustainable management strategies. Using observed records from 15 hydrological stations and 85 national meteorological stations from 1980 to 2013, the decomposition method, based on the Budyko hypothesis, is used to quantify the impact of climate variation and anthropogenic interference on annual runoff for the 12 catchments in the Loess Plateau. The results show the following: (1 the observed annual runoff exhibited a negative trend in all 12 catchments (significant in eight catchments with a range of −1.94 to −0.16 mm·year−1 and exhibited a substantial difference before and after 1999; (2 the sensitivity of runoff to vegetation change, precipitation, and potential evapotranspiration increased in most catchments after 1999, indicating that great challenges and uncertainties might be introduced to regional water resource availability; and (3 the anthropogenic interference, particularly LUCC caused by forest strategies, has become the main contribution to runoff change. We suggest that more attention should be given to water resource availability and that the hydrologic consequences of revegetation should be taken into account in future management.

  2. New insights into trace elements deposition in the snow packs at remote alpine glaciers in the northern Tibetan Plateau, China.

    Science.gov (United States)

    Dong, Zhiwen; Kang, Shichang; Qin, Xiang; Li, Xiaofei; Qin, Dahe; Ren, Jiawen

    2015-10-01

    Trace element pollution resulting from anthropogenic emissions is evident throughout most of the atmosphere and has the potential to create environmental and health risks. In this study we investigated trace element deposition in the snowpacks at two different locations in the northern Tibetan Plateau, including the Laohugou (LHG) and the Tanggula (TGL) glacier basins, and its related atmospheric pollution information in these glacier areas, mainly focusing on 18 trace elements (Li, Be, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Nb, Mo, Cd, Sb, Cs, Ba, Tl, and Pb). The results clearly demonstrate that pronounced increases of both concentrations and crustal enrichment factors (EFs) are observed in the snowpack at the TGL glacier basin compared to that of the LHG glacier basin, with the highest EFs for Sb and Zn in the TGL basin, whereas with the highest EFs for Sb and Cd in the LHG basin. Compared with other studies in the Tibetan Plateau and surrounding regions, trace element concentration showed gradually decreasing trend from Himalayan regions (southern Tibetan Plateau) to the TGL basin (central Tibetan Plateau), and to the LHG basin (northern Tibetan Plateau), which probably implied the significant influence of atmospheric trace element transport from south Asia to the central Tibetan Plateau. Moreover, EF calculations at two sites showed that most of the heavy metals (e.g., Cu, Zn, Mo, Cd, Sb, and Pb) were from anthropogenic sources and some other elements (e.g., Li, Rb, and Ba) were mainly originated from crustal sources. MODIS atmospheric optical depth (AOD) fields derived using the Deep Blue algorithm and CALIOP/CALIPSO transect showed significant influence of atmospheric pollutant transport from south Asia to the Tibetan Plateau, which probably caused the increased concentrations and EFs of trace element deposition in the snowpack on the TGL glacier basin.

  3. Attenuation relations for horizontal peak ground acceleration and response spectrum in northeastern Tibetan Plateau region

    Institute of Scientific and Technical Information of China (English)

    俞言祥; 汪素云

    2004-01-01

    The seismic intensity attenuation relations in northeastern Tibetan Plateau region are established by a regression analysis on isoseismal data. Then the attenuation relations for horizontal peak ground acceleration and short-period response spectrum for western North America are derived based on the database of HUO Jun-rong and strong motion data from recent earthquakes. The attenuation relations of long-period response spectrum for western North America are developed by analyzing the broadband digital seismic recordings of southern California. By integrating the short-period and long-period attenuation relationships, the attenuation relations for horizontal acceleration response spectrum in the period range of 0.04~6 s for western North America are established. The attenuation equation that accounts for the magnitude saturation and near-field saturation of high frequency ground motion is used. Finally the attenuation relations for horizontal peak ground acceleration and response spectrum for the region of northeastern Tibetan Plateau are developed by using the transforming method.

  4. The impacts of urbanization on soil erosion in the Loess Plateau region

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The accelerated urbanization has resulted in new soil erosion inthe Loess Plateau region since the 1980s. A concept of urban erosion and its impacts on environment are discussed. The experimental studies and field investigations show that those loose silt and earth piles formed by urban construction can be eroded seriously: Under stormy rain, the amount of sediment from steep man-dumped slope is 10.8-12.2 times that of from uncovered slope land; the result of experiments with the wind tunnel also shows that the damage to the surface structure of dry loess can cause serious soil erosion by wind in some cities of the region. Even if in the urban built-up area, there are many loose sandy soil, mud and silt, which are washed into rivers by city's ground flow in the rainy season.So, anthropogenically induced soil erosion has made soil erosion more serious around the urban areas.And the urban eroded environment has several characteristics such as fragility, complexity,seasonality and quick variability. Urban areas witness a quick economic growth and have more construction projects than rural areas, which brings more intensive changes of environments during a short period of time or adds some new elements to the erosion system. Therefore erosion has experienced more intensive impact by human activities. So, the possible impact of urbanization on erosion environment must be taken into consideration when designing or planning to exploit natural rsources or to develop urban areas in the Loess Plateau.

  5. China's Policymaking for Regional Economic Cooperation

    DEFF Research Database (Denmark)

    Jiang, Yang

    Yang Jiang opens the black box of China's policymaking for free trade agreements and key regional financial initiatives. Using first-hand interview data, she sheds light on the key trends of China's trade and financial politics after its WTO entry in 2001. In particular, she highlights...... the influence of competing domestic interests, protectionist and conservative forces vis-a-vis liberal and reformist forces; government agencies, ministries and national commissions, local governments; and different ideas on China's foreign economic policy. In doing so, she also provides interesting comparisons...

  6. Recent, slow normal and strike-slip faulting in the Pasto Ventura region of the southern Puna Plateau, NW Argentina

    Science.gov (United States)

    Zhou, Renjie; Schoenbohm, Lindsay M.; Cosca, Michael

    2013-01-01

    Recent normal and strike-slip faulting on the Puna Plateau of NW Argentina has been linked to lithospheric foundering, gravitational spreading, plate boundary forces and a decrease in crustal shortening from north to south. However, the timing, kinematics and rate of extension remain poorly constrained. We focus on the Pasto Ventura region (NW Argentina) located on the southern Puna Plateau and recent deformation (cinder cones show that the overall extension direction is subhorizontal, is oriented NE-SW to NNE-SSW, and occurs at a slow, time-integrated rate of 0.02 to 0.08 mm/yr since at least 0.8–0.5 Ma. A regional compilation from this study and existing data shows that recent extension across the Puna Plateau is subhorizontal but varies in azimuthal orientation dramatically. Data from the Pasto Ventura region are consistent with a number of models to explain normal and strike-slip faulting on the Puna Plateau, all of which likely influence the region. Some role for lower lithospheric foundering through dripping appears to be seen based on the regional extension directions and ages of mafic volcanism in the southern Puna Plateau.

  7. Review of Digital Elevation Model (DEM) Based Research on China Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    Tang Guo'an; Ge Shanshan; Li Fayuan; Zhou Jieyu

    2005-01-01

    The Loess Plateau is one of the hot research areas for its specific geographical features. In resent years, with the establishment of national multi-scale DEMs and the perfection of DEM based digital terrain analysis methods, new thoughts and methodologies have been constructed for the Loess Plateau research. This paper introduces the characteristics of DEM data, analyses the development stages of DEM applied in the Loess Plateau research, and discusses its further possible research direction. More discussions are focused on slope spectrum and its concept, as well as the significance in the Loess Plateau research.

  8. Optimizing water and nitrogen inputs for winter wheat cropping system on the Loess Plateau, China

    Institute of Scientific and Technical Information of China (English)

    QiuPing FU; QuanJiu WANG; XinLei SHEN; Jun FAN

    2014-01-01

    Optimal use of water and fertilizers can enhance winter wheat yield and increase the efficiencies of water and fertilizer usage in dryland agricultural systems. In order to optimize water and nitrogen (N) management for winter wheat, we conducted field experiments from 2006 to 2008 at the Changwu Agro-ecological Experimental Station of the Chinese Academy of Sciences on the Loess Plateau, China. Regression models of wheat yield and evapotranspiration (ET) were established in this study to evaluate the water and fertilizer coupling effects and to determine the optimal coupling domain. The results showed that there was a positive effect of water and N fertilizer on crop yield, and optimal irrigation and N inputs can significantly increase the yield of winter wheat. In the drought year (2006-2007), the maximum yield (Ymax) of winter wheat was 9.211 t/hm2 for the treatment with 324 mm irriga-tion and 310 kg/hm2 N input, and the highest water use efficiency (WUE) of 16.335 kg/(hm2⋅mm) was achieved with 198 mm irrigation and 274 kg/hm2 N input. While in the normal year (2007-2008), the maximum winter wheat yield of 10.715 t/hm2 was achieved by applying 318 mm irrigation and 291 kg/hm2 N, and the highest WUE was 18.69 kg/(hm2⋅mm) with 107 mm irrigation and 256 kg/hm2 N input. Crop yield and ET response to irrigation and N inputs followed a quadratic and a line function, respectively. The optimal coupling domain was determined using the elas-ticity index (EI) and its expression in the water-N dimensions, and was represented by an ellipse, such that the global maximum WUE (WUEmax) and Ymax values corresponded to the left and right end points of the long axis, respectively. Considering the aim to get the greatest profit in practice, the optimal coupling domain was represented by the lower half of the ellipse, with the Ymax and WUEmax on the two end points of the long axis. Overall, we found that the total amount of irrigation for winter wheat should not exceed 324 mm. In

  9. Physical structure features of the crust at southeast region of Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    刘宏兵; 孔祥儒; 马晓冰; 王谦身; 闫永利; 闫雅芬; 杨志强

    2001-01-01

    Research results show the obvious differences between the crustal deep physical features of each block and fault zone, and obvious inhomogeneity in longitudinal and horizontal directions. The Gandise block is especially outstanding. Squeezed by Indian Continent, the high conductive layer inclines northward, which is continuous in the Gandise block, but becomes horizontal in distribution and thick in Qiangtang and Bayan Har blocks. The Jinshajiang fault zone inclines northward near Yushu, while Lancangjiang and Nujiang fault zones present vertical distributions. Gravity Bouguer anomalies are high at the south and north edges and low in the center of the plateau. The Zayu-Shama region has not reached gravity equilibrium yet and represents obvious negative anomaly, which indicates that the region is in rapid uplift. Its geomagnetic anomaly varies evidently in different blocks and on different fault zones, and decreases obviously both in intensity and amplitude variations from south to north. The surveys and

  10. A study of scale effect on specific sediment yield in the Loess Plateau,China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on data from 148 hydrometric stations in the Yellow River Basin, an analysis of regional scale relationship, or the relationship between specific sediment yield and drainage basin area, has been undertaken in the study area of the Loess Plateau. For different regions, scale relationship in log-log ordinate can be fitted by two types of lines: straight and parabola, and for each line, a function was fitted using regression analysis. The different scale relationships have been explained in terms of the difference in surface material distribution and landforms. To offset the scale-induced influence, calcu-lation has been done based on the fitted functions, in order to adjust the data of specific sediment yield to a common standard area. Based on the scaled data, a map of specific sediment yield was con-structed using Kriging interpolation. For comparison, a map based on the un-scaled data of specific sediment yield was also constructed using the same method. The two maps show that the basic pattern of specific sediment yield was basically the same. The severely eroded areas (Ys >10000 t km-2a-1) were at the same locations from Hekouzhen to Longmen in the middle Yellow River Basin. However, after the adjustment to a common standard area, the very severely eroded area (Ys >20000 t km-2a-1) became much enlarged because after the adjustment, all the values of Ys in the lower river basin in those regions became much larger than before.

  11. Tardigrada of Xinjiang Uygur Autonomous Region, China

    Directory of Open Access Journals (Sweden)

    William R. MILLER

    2007-09-01

    Full Text Available Relatively little is known of the Tardigrada fauna of China, and there are no previous tardigrade records for Xinjiang Uygur Autonomous Region, China's largest administrative division. Moss specimens of the Missouri Botanical Garden Herbarium (St. Louis, U.S.A. were used as a source of tardigrades from this region. Of the 270 moss specimens sampled, 78 yielded tardigrades. Species found were Bryodelphax asiaticus, Cornechiniscus holmeni, Echiniscus blumi, Echiniscus canadensis, Echiniscus granulatus, Echiniscus testudo, Echiniscus trisetosus, Macrobiotus alekseevi, Macrobiotus mauccii, Milnesium asiaticum, Milnesium longiungue, and Milnesium tardigradum. Of the species found, the Heterotardigrada are better represented, which is probably a reflection of the higher altitudes at which the samples were taken and the arid environment of the region; the species found are primarily ones considered to be xerophilic or montane. Seven species new to China are reported.

  12. A preliminary investigation of the dynamic characteristics of dried soil layers on the Loess Plateau of China

    Science.gov (United States)

    Wang, Yunqiang; Shao, Ming'an; Shao, Hongbo

    2010-02-01

    SummarySerious soil desiccation, resulting from climatic conditions and poor land management, may lead to the formation of a dried soil layer (DSL), which can negatively affect ecological and hydrological processes. To mitigate these effects through management, it is necessary to understand property interactions within DSLs, compared with those in the whole soil profile, and DSL formation processes under different land uses. We investigated the relationships between soil water content (SWC) and plant root indices, and other soil properties, under various land uses in the Liudaogou watershed on the Loess Plateau, China. We also studied the development of DSLs as a function of the growth age of two vegetation types. Rate of formation and thickness of DSLs were dependent on vegetation type: DSLs formed after 2 years of alfalfa ( Medicago sativa) growth and 3 years of Caragana korshinskii growth; after 4 years of growth, DSLs under alfalfa were thicker than those under C. korshinskii, but after 31 years the DSL thickness under C. korshinskii (4.4 m) exceeded that formed under alfalfa (3 m). The more persistent DSLs occurred below a 100 cm thick upper soil layer that was seasonally dried and replenished by rainfall under both vegetation types. The degree of soil desiccation under natural vegetation was generally less than that under non-indigenous plant species, and was similarly less over a period of about 30 years for a natural plant succession sequence than for an artificial one. Thus, the use of natural vegetation succession management principles would possibly reduce soil desiccation during vegetative restoration. Densities of root length, weight, and surface area, and the average root diameter of soybean ( Glycine max), alfalfa, Stipa bubgeana, and C. korshinskii all decreased with increases in soil depths below 20 cm. Correlations between SWC and root indices, and various soil physical and chemical properties, were generally weaker within the DSL layers than

  13. Regional Variations of the ω-upper Bound Magnitude of GIII Distribution in the Iranian Plateau

    Science.gov (United States)

    Mohammadi, Hiwa; Bayrak, Yusuf

    2016-08-01

    The Iranian Plateau does not appear to be a single crustal block, but an assemblage of zones comprising the Alborz—Azerbaijan, Zagros, Kopeh—Dagh, Makran, and Central and East Iran. The Gumbel's III asymptotic distribution method (GIII) and maximum magnitude expected by Kijko—Sellevoll method is applied in order to check the potentiality of the each seismogenic zone in the Iranian Plateau for the future occurrence of maximum magnitude ( M max). For this purpose, a homogeneous and complete seismicity database of the instrumental period during 1900-2012 is used in 29 seismogenic zones of the examined region. The spatial mapping of hazard parameters (upper bound magnitude ( ω), most probable earthquake magnitude in next 100 years ( M 100) and maximum magnitude expected by maximum magnitude estimated by Kijko—Sellevoll method (max M K - S max) reveals that Central and East Iran, Alborz and Azerbaijan, Kopeh—Dagh and SE Zagros are a dangerous place for the next occurrence of a large earthquake.

  14. Thawing and freezing processes of active layer in Wudaoliang region of Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The interaction between permafrost and atmosphere is accomplished through transfer of heat and moisture in the overlay active layer. Thus, the research on the thermal and hydro- dynamics of active layer during the thawing and freezing processes was considered a key to revealing the heat and moisture exchanges between permafrost and atmosphere. The monitoring and research on active layer were conducted because permafrost occupies about two thirds of the total area of the Tibetan Plateau. Based on the analysis of the ground temperature data and soil moisture data of monitoring near the Wudaoliang region of the Tibetan Plateau, the thawing and freezing processes of active layer were divided into four stages, i.e. summer thawing stage (ST), autumn freezing stage (AF), winter cooling stage (WC) and spring warming stage (SW). Coupled heat and water flow is much more complicated in ST and AF, and more amount of water is migrating in these two stages. Heat is transferred mainly via conductive heat flow in the other two stages, and less water migrated. Four water migration and coupled heat flow processes were addressed for the thawing and freezing stages, which are water infiltration driven by gravity, moisture advection and distillation driven by temperature and osmotic gradients, water migration driven by capillarity and unfrozen water migration driven by temperature gradient. The water content near the permafrost table tends to increase after one thawing and freezing cycle, which is the main reason for the development of thick ground ice layer near permafrost table.

  15. Effects of Stubble Management on Soil Fertility and Crop Yield of Rainfed Area in Western Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    G. B. Huang

    2012-01-01

    Full Text Available The combination of continuous cereal cropping, tillage and stubble removal reduces soil fertility and increases soil erosion on sloping land. The objective of the present study was to assessment soil fertility changes under stubble removal and stubble retention in the Loess Plateau where soil is prone to severe erosion. It was indicated that soil N increased a lot for and two stubble retention treatments had the higher N balance at the end of two rotations. Soil K balance performed that soil K was in deficient for all treatments and two stubble retention treatments had lower deficit K. The treatments with stubble retention produced higher grain yields than the stubble removal treatments. It was concluded that stubble retention should be conducted to increase crops productivity, improve soil fertility as well as agriculture sustainability in the Loess plateau, China.

  16. Sedimentary Record of the Planation Surface in the Hoh Xil Region of the Northern Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Miocene marl is the most widespread Tertiary stratigraphic record in the northern Tibet Plateau, termed the Wudaoliang Group in the Hoh Xil region and the correlative Suonahu Formation in the Qiangtang region.The uniform marl overlies red beds of the Eocene-Oligocene Fenghuoshan Group. The Wudaoliang Group is generally 100-400 m thick, but the thickest strata are 700-1300 m, located in the Haidinghu (Haiding Lake) and Tuotuohe (Tuotuo River) regions respectively. Based on observations from eight measured sections and outcrops, the thinbedded marl, which varies in colour from grey-white to light brown-grey, is explained as a large-scale or serial lacustrine deposit stretching throughout northern Tibet. The Wudaoliang Group commonly crops out on geographic lowland at an average elevation of 4600 m above sea level within the mountain chains, showing concordant summit levels, e.g. the Fenghuoshan and Bairizhajia Mountains. These mountains with a flat ridge are considered to be remains of the palaeo-planation surface. However, the spatial distribution of the Wudaoliang Group is not confined by the current mountain-basin landform configuration.We have observed the Miocene Wudaoliang Group marl exposed on a 5233 m-high mountain peak. The largest difference in height between the current lake level and the mesa crest is 600 m; the maximum dip angle is 25°, but usually below 10°, which is obviously different from the Fenghuoshan Group red beds with moderate to strong structural deformation. The horizon of the Wudanliang Group thin-bedded marl and its widespread occurrence throughout the northern Tibetan Plateau can only be reasonably inferred to a sedimentary record relevant to the palaeo-planation. Its deposition occurred on primary land floor by erosion at 20 Ma and its bed surface is a typical sign of geomorphic rise and collapse after the erosion.

  17. Evaluating the coupling effects of climate aridity and vegetation restoration on soil erosion over the Loess Plateau in China.

    Science.gov (United States)

    Zhang, Baoqing; He, Chansheng; Burnham, Morey; Zhang, Lanhui

    2016-01-01

    In this study, the coupling effects of climate aridity and vegetation restoration on runoff and sediment yield over the Loess Plateau were examined and characterized. To take into consideration the complexity of drought, as well as the varied strengths and weaknesses of different drought measures, two drought indices are selected to identify and evaluate drought variability. The Normalized Difference Vegetation Index (NDVI) data were obtained to monitor and express spatiotemporal variations in vegetation cover. The results show that most regions of the Loess Plateau experienced increasingly severe droughts over the past 40years, and these regions comprise the major source of the Yellow River sediment. Climatic drying initially occurred in the 1990s, and became statistically significant in 2000s. The increasingly severe droughts could negatively impact surface and groundwater supplies as well as soil water storage, but may also minimize surface runoff yield, which is one of the major causes of soil erosion on the Loess Plateau. Vegetation cover on the Loess Plateau was significantly improved after the implementation of "Grain for Green" project, which were helpful for controlling severe soil erosion. With the impacts of the construction of check dams, terraces and large reservoirs, runoff and sediment yield over the Loess Plateau initially exhibited downward trends between 1970 and 1990. After 1990, with the effects of the climate warming and drying, a second sharp reduction in runoff and sediment yield occurred. The coupling effects of climate aridity and vegetation restoration have led to a third significant decrease in runoff and sediment yield over the Loess Plateau after 2000.

  18. Analysis of surface air temperature variations and local urbanization effects on central Yunnan Plateau, SW China

    Science.gov (United States)

    He, Yunling; Wu, Zhijie; Liu, Xuelian; Deng, Fuying

    2016-10-01

    With the surface air temperature (SAT) data at 37 stations on Central Yunnan Plateau (CYP) for 1961-2010 and the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime light data, the temporal-spatial patterns of the SAT trends are detected using Sen's Nonparametric Estimator of Slope approach and MK test, and the impact of urbanization on surface warming is analyzed by comparing the differences between the air temperature change trends of urban stations and their corresponding rural stations. Results indicated that annual mean air temperature showed a significant warming trend, which is equivalent to a rate of 0.17 °C/decade during the past 50 years. Seasonal mean air temperature presents a rising trend, and the trend was more significant in winter (0.31 °C/decade) than in other seasons. Annual/seasonal mean air temperature tends to increase in most areas, and higher warming trend appeared in urban areas, notably in Kunming city. The regional mean air temperature series was significantly impacted by urban warming, and the urbanization-induced warming contributed to approximately 32.3-62.9 % of the total regional warming during the past 50 years. Meantime, the urbanization-induced warming trend in winter and spring was more significant than that in summer and autumn. Since 1985, the urban heat island (UHI) intensity has gradually increased. And the urban temperatures always rise faster than rural temperatures on the CYP.

  19. Human impacts on functional and taxonomic homogenization of plateau fish assemblages in Yunnan, China

    Directory of Open Access Journals (Sweden)

    Guohuan Su

    2015-07-01

    Full Text Available Human activities and the consequent extinctions of native species and invasions of non-native species have been changing the composition of species assemblages worldwide. These anthropogenic impacts alter not only the richness of assemblages but also the biological dissimilarity among them. However, much of the research effort to date has focused on changes in taxonomic dissimilarity (i.e. accounting for species composition whether assessments of functional dissimilarity (i.e. accounting for the diversity of biological traits are much more scarce, despite revealing important complimentary information by accounting for changes in the diversity of biological traits. Here, we assess the temporal (1950s against 2000s changes in both taxonomic and functional dissimilarities of freshwater fish assemblages across lakes from the Yunnan Plateau in China. The Jaccard index to quantify the changes in both taxonomic and functional dissimilarity. We then partitioned dissimilarity to extract its turnover component and measured the changes in the contribution of turnover to dissimilarity. We found that functional and taxonomic homogenization occurred simultaneously. However, patterns between these two processes differed for some lakes. Taxonomic and functional homogenizations were stronger when the historical level of taxonomic dissimilarity among assemblages was high. The impact of extinctions of native species and invasions of non-native species on homogenization was otherwise complex to disentangle with no significant effect of any of the studied environmental factors. In agreement with other studies, our study proved that change in taxonomic dissimilarity cannot be used to predict changes in functional dissimilarity and, as an indicator of ecosystem functioning, functional dissimilarity should be used together with taxonomic dissimilarity to attain a more holistic understanding of human impacts on natural ecosystems.

  20. Soil moisture and evapotranspiration of different land cover types in the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    S. Wang

    2012-08-01

    Full Text Available We studied the impacts of re-vegetation on soil moisture dynamics and evapotranspiration (ET of five land cover types in the Loess Plateau in northern China. Soil moisture and temperature variations under grass (Andropogon, subshrub (Artemisia scoparia, shrub (Spiraea pubescens, plantation forest (Robinia pseudoacacia, and crop (Zea mays vegetation were continuously monitored during the growing season of 2011. There were more than 10 soil moisture pulses during the period of data collection. Surface soil moisture of all of the land cover types showed an increasing trend in the rainy season. Soil moisture under the corn crop was consistently higher than the other surfaces. Grass and subshrubs showed an intermediate moisture level. Grass had slightly higher readings than those of subshrub most of the time. Shrubs and plantation forests were characterized by lower soil moisture readings, with the shrub levels consistently being slightly higher than those of the forests. Despite the greater post-rainfall loss of moisture under subshrub and grass vegetation than forests and shrubs, subshrub and grass sites exhibit a higher soil moisture content due to their greater soil retention capacity in the dry period. The daily ET trends of the forests and shrub sites were similar and were more stable than those of the other types. Soils under subshrubs acquired and retained soil moisture resources more efficiently than the other cover types, with a competitive advantage in the long term, representing an adaptive vegetation type in the study watershed. The interactions between vegetation and soil moisture dynamics contribute to structure and function of the ecosystems studied.

  1. Preliminary analysis on the relationships between Tibetan Plateau NDVI change and its surface heat source and precipitation of China

    Institute of Scientific and Technical Information of China (English)

    HUA Wei; FAN GuangZhou; ZHOU DingWen; NI ChangJian; LI XueMin; WANG YongLi; LIU YaQin; HUANG XianLun

    2008-01-01

    Using the automatic weather station data obtained from the Tibetan Plateau (TP), the normalized dif-ference vegetation index and the monthly precipitation data of China and by the methods of correlation and composite analysis, preliminary analytical results are achieved concerning the relationships be-tween TP NDVI change and its surface heat source and precipitation of China. The results of our re-search may lead to the following conclusions: (1) A positive correlation relationship exists between TP NDVI change and its surface heat source, including the sensible heat and the latent heat. As to the correlation of the former, it is more remarkable in western TP than in eastern TP, and as to the correla-tion of the latter, however it turns out contrary. (2) With the improvement of TP vegetation, its surface heat source of every season is also mainly reinforced, especially in summer. As to the contribution of the sensible heat and the latent heat to the increment of the TP surface heat source intensity, the for-mer is comparatively more significant than the latter in winter and spring, while in summer and autumn, the two have almost the same importance. (3) The correlation coefficient between summer NDVI over TP and the corresponding period precipitation of China displays a belt distribution of "+-+" from south to north China. (4) Anomalous surface heating field over TP derived from vegetation change is probably an important factor to affect summer precipitation of China.keywords Tibetan Plateau, vegetation change, surface heat source, precipitation of China.

  2. Recent Progress in the Impact of the Tibetan Plateau on Climate in China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Studies of the impacts of the Tibetan Plateau (TP) on climate in China in the last four years are reviewed.It is reported that temperature and precipitation over the TP have increased during recent decades.From satellite data analysis,it is demonstrated that most of the precipitation over the TP is from deep convection clouds.Moreover,the huge TP mechanical forcing and extraordinary elevated thermal forcing impose remarkable impacts upon local circulation and global climate.In winter and spring,stream flow is deflected by a large obstacle and appears as an asymmetric dipole,making East Asia much colder than mid Asia in winter and forming persistent rainfall in late winter and early spring over South China.In late spring,TP heating contributes to the establishment and intensification of the South Asian high and the abrupt seasonal transition of the surrounding circularions.In summer,TP heating in conjunction with the TP air pump cause the deviating stream field to resemble a cyclonic spiral,converging towards and rising over the TP.Therefore,the prominent Asian monsoon climate over East Asia and the dry climate over mid Asia in summer are forced by both TP local forcing and Eurasian continental forcing.Due to the longer memory of snow and soil moisture,the TP thermal status both in summer and in late winter and spring can infuence the variation of Eastern Asian summer rainfall.A combined index using both snow cover over the TP and the ENSO index in winter shows a better seasonal forecast.On the other hand,strong sensible heating over the Tibetan Platean in spring contributes significantly to anchor the earliest Asian monsoon being over the eastern Bay of Bengal (BOB) and the western Indochina peninsula.Qualitative prediction of the BOB monsoon onset was attempted by using the sign of meridional temperature gradient in March in the upper troposphere,or at 400 hPa over the TP.It is also demonstrated by a numerical experiment and theoretical study that the heating over

  3. Optimization of Land Use Pattern Reduces Surface Runoff and Sediment Loss in a Hilly-Gully Watershed at the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    Han Yini

    2016-04-01

    Full Text Available Aim of study: The aim is to find a way increasing gain yield and lessen area of farmland, and then increasing vegetation cover, improving environment and alleviating soil erosion.Area of study: The Hilly-Gully region at the loess plateau of China.Material and methods: In this study, an adjusted and optimized land use pattern was developed in Luoyugou watershed in the Yellow River valley based on the gradient distribution of land use types, and its effect on water and sediment transport was simulated using the SWAT model and GIS, with remote sensing images, land use maps and hydrologic data.Main results: The results indicate: average simulated runoff and sediment for the period 1986-2000 under conditions of the three land use pattern (2011, 2008 and optimized land use reduced by 0.002-0.013 m3/s (2.7-17.6% and 0.66 million tons, respectively. The runoff and sediment data obtained were compared with observed data from 2008, which showed that runoff and sediment production would be reduced by 467625 m3 and 22754 tons, respectively.Research highlights: The adjustment of the land use pattern in comprehensive consideration of vegetation and geography have a positive effect on water and sediment transport which will be important for decision making and water resources management, and provides a reference for future environmental management and ecological construction in the loess plateau Hilly-Gully region

  4. Carbonaceous matter deposition in the high glacial regions of the Tibetan Plateau

    Science.gov (United States)

    Li, Chaoliu; Chen, Pengfei; Kang, Shichang; Yan, Fangping; Li, Xiaofei; Qu, Bin; Sillanpää, Mika

    2016-09-01

    Carbonaceous matter at glacial region plays important role in river ecosystems fed by glacier and albedo reduction of glacier surface. However, currently, limited knowledge are available on the carbonaceous matter within the glacial region of the Tibetan Plateau (TP). In this study, the data from six snowpits in the glacial region across the TP were reported. The results showed that dissolved organic carbon (DOC) concentrations of snowpit samples of the TP were comparable to those of European Alps and the Arctic. The ratio of DOC to carbonaceous matter (40.25 ± 8.98%) was lower than that of Alpine glaciers, thus indicating greater particulate carbon content in the TP glacial region. In addition, the DOC was significantly correlated with insoluble particulate carbon (IPC), indicating that IPC and DOC likely came from the same sources. Spatially, the DOC concentration decreased from the north (0.42 ± 0.29 mg-C L-1) to the south TP (0.15 ± 0.06 mg-C L-1), which was consistent with variations in the distribution of dust storm on the TP. Principal component analysis of major ions and DOC showed that mineral dust contributed the major part of DOC, followed by biogenic sources such as agriculture and livestock. Finally, based on DOC concentrations and precipitation amounts at different periods, the mean annul flux of DOC in the glacial region of the TP was calculated to be 0.11 ± 0.05 g-C m-2 yr-1.

  5. Responses of terrestrial ecosystems' net primary productivity to future regional climate change in China.

    Directory of Open Access Journals (Sweden)

    Dongsheng Zhao

    Full Text Available The impact of regional climate change on net primary productivity (NPP is an important aspect in the study of ecosystems' response to global climate change. China's ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund-Potsdam-Jena Dynamic Global Vegetation Model for China (LPJ-CN, a global dynamical vegetation model developed for China's terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change.

  6. Responses of terrestrial ecosystems' net primary productivity to future regional climate change in China.

    Science.gov (United States)

    Zhao, Dongsheng; Wu, Shaohong; Yin, Yunhe

    2013-01-01

    The impact of regional climate change on net primary productivity (NPP) is an important aspect in the study of ecosystems' response to global climate change. China's ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund-Potsdam-Jena Dynamic Global Vegetation Model for China (LPJ-CN), a global dynamical vegetation model developed for China's terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change.

  7. Soil organic carbon stabilization by iron in permafrost regions of the Qinghai-Tibet Plateau

    Science.gov (United States)

    Mu, C. C.; Zhang, T. J.; Zhao, Q.; Guo, H.; Zhong, W.; Su, H.; Wu, Q. B.

    2016-10-01

    A close relationship exists between soil organic carbon (SOC) and reactive iron; however, little is known about the role of iron in SOC preservation in permafrost regions. We determined the amount of SOC associated with reactive iron phases (OC-Fe) in the permafrost regions of the Qinghai-Tibetan Plateau (QTP). The results showed that the percentage of OC-Fe ranged between 0.9% and 59.5% in the upper 30 cm of soil and that the OC-Fe represented 19.5 ± 12.3% of the total SOC pool. No clear vertical distribution pattern in OC-Fe was present in the upper 1 m of soil. Throughout the year, the OC-Fe accounted for relatively stable proportions of the total SOC pool. This study suggests that approximately 20% of SOC is a potential rusty OC pool in the permafrost regions of the QTP. Biogeochemical processes related to the reaction of iron may play important roles in soil carbon cycles in permafrost regions.

  8. Ground-Water Availability Assessment for the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    ,

    2008-01-01

    The U.S. Geological Survey (USGS) is assessing the availability and use of the Nation's water resources to gain a clearer understanding of the status of our water resources and the land-use, water-use, and climatic trends that affect them. The goal of the National assessment is to improve our ability to forecast water availability for future economic and environmental uses. Assessments will be completed for regional aquifer systems across the Nation to help characterize how much water we have now, how water availability is changing, and how much water we can expect to have in the future (Reilly and others, 2008). Water availability is a function of many factors, including the quantity and quality of water, and the laws, regulations, economics, and environmental factors that control its use. The focus of the Columbia Plateau regional ground-water availability assessment is to improve fundamental knowledge of the ground-water balance of the region, including the flows, storage, and ground-water use by humans. An improved quantitative understanding of the region's water balance not only provides key information about water quantity, but also can serve as a fundamental basis for many analyses of water quality and ecosystem health.

  9. Abatement costs of soil conservation in China's Loess Plateau: balancing income with conservation in an agricultural system.

    Science.gov (United States)

    Hou, Lingling; Hoag, Dana L K; Keske, Catherine M H

    2015-02-01

    This study proposes the use of marginal abatement cost curves to calculate environmental damages of agricultural systems in China's Loess Plateau. Total system costs and revenues, management characteristics and pollution attributes are imputed into a directional output distance function, which is then used to determine shadow prices and abatement cost curves for soil and nitrogen loss. Marginal abatement costs curves are an effective way to compare economic and conservation tradeoffs when field-specific data are scarce. The results show that sustainable agricultural practices can balance soil conservation and agricultural production; land need not be retired, as is current policy.

  10. Carbon sequestration function of check-dams: a case study of the Loess plateau in China.

    Science.gov (United States)

    Wang, Yafeng; Chen, Liding; Gao, Yang; Wang, Shuai; Lü, Yihe; Fu, Bojie

    2014-11-01

    Check-dams are the most common structures for controlling soil erosion in the Loess Plateau. However, the effect of check-dams on carbon sequestration, along with sediment transport and deposition, has not been assessed over large areas. In this study, we evaluated the carbon sequestration function of check-dams in the Loess Plateau. The results indicate that there were approximately 11 000 check-dams distributed in the Loess Plateau, with an estimate of the amount of sediment of 21 × 10⁹ m³ and a soil organic carbon storage amount of 0.945 Pg. Our study reveals that check-dams in the Loess Plateau not only conserve soil and water but also sequester carbon.

  11. Changes to the Natural Regional Boundaries in China During 1961-2007

    Institute of Scientific and Technical Information of China (English)

    YU Zhen-Yan; FAN Guang-Zhou; DONG Yi-Ping; WANG Lei; HUA Wei; ZHOU Ding-Wen

    2011-01-01

    Daily temperature data from 599 stations across China for the years 1961 to 2007 were used to analyze the changes in the natural regional boundaries. The results show that the accumulated temperature ≥10℃ and its duration changed dramatically from the end of 1990s to the early 21 st century. The amplitude of natural regional boundaries was greater in the 21st century than it was in the 20th century. In the eastern region of China, the climatic zones were migrating generally northward, with the northern edge of the subtropical zone and the eastern section of the warm temperate zone showing an obvious northward shift of up to 1-3° of latitude. The climatic zones moved south in the Qinghal-Tibet Plateau, western Inner Mongolia, and some areas of western Xinjiang, and slightly to the north in other parts of the western region.

  12. Phylogeography of the South China field mouse (Apodemus draco on the southeastern Tibetan Plateau reveals high genetic diversity and glacial refugia.

    Directory of Open Access Journals (Sweden)

    Zhenxin Fan

    Full Text Available The southeastern margin of the Tibetan Plateau (SEMTP is a particularly interesting region due to its topographic complexity and unique geologic history, but phylogeographic studies that focus on this region are rare. In this study, we investigated the phylogeography of the South China field mouse, Apodemus draco, in order to assess the role of geologic and climatic events on the Tibetan Plateau in shaping its genetic structure. We sequenced mitochondrial cytochrome b (cyt b sequences in 103 individuals from 47 sampling sites. In addition, 23 cyt b sequences were collected from GenBank for analyses. Phylogenetic, demographic and landscape genetic methods were conducted. Seventy-six cyt b haplotypes were found and the genetic diversity was extremely high (π = 0.0368; h = 0.989. Five major evolutionary clades, based on geographic locations, were identified. Demographic analyses implied subclade 1A and subclade 1B experienced population expansions at about 0.052-0.013 Mya and 0.014-0.004 Mya, respectively. The divergence time analysis showed that the split between clade 1 and clade 2 occurred 0.26 Mya, which fell into the extensive glacial period (EGP, 0.5-0.17 Mya. The divergence times of other main clades (2.20-0.55 Mya were congruent with the periods of the Qingzang Movement (3.6-1.7 Mya and the Kun-Huang Movement (1.2-0.6 Mya, which were known as the most intense uplift events in the Tibetan Plateau. Our study supported the hypothesis that the SEMTP was a large late Pleistocene refugium, and further inferred that the Gongga Mountain Region and Hongya County were glacial refugia for A. draco in clade 1. We hypothesize that the evolutionary history of A. draco in the SEMTP primarily occurred in two stages. First, an initial divergence would have been shaped by uplift events of the Tibetan Plateau. Then, major glaciations in the Pleistocene added complexity to its demographic history and genetic structure.

  13. High-Resolution Regional Phase Attenuation Models of the Iranian Plateau and Surrounding Regions

    Science.gov (United States)

    2014-03-03

    Mayeda, W. R. Walter, L. Malagnini, and W. S. Phillips, Regional Attenuation in Northern California: A Comparison of Five 1D Q Methods, Bull. Seism ...regional phase amplitude tomography, Seism . Res. Lett., 80, p. 360, 2009. Approved for public release; distribution is unlimited. 49 Priestley, K

  14. Variations in Regional Mean Daily Precipitation Extremes and Related Circulation Anomalies over Central China During Boreal Summer

    Institute of Scientific and Technical Information of China (English)

    柯丹; 管兆勇

    2014-01-01

    The variations of regional mean daily precipitation extreme (RMDPE) events in central China and associated circulation anomalies during June, July, and August (JJA) of 1961-2010 are investigated by using daily in-situ precipitation observations and the NCEP/NCAR reanalysis data. The precipitation data were collected at 239 state-level stations distributed throughout the provinces of Henan, Hubei, and Hunan. During 1961-2010, the 99th percentile threshold for RMDPE is 23.585 mm day-1. The number of RMDPE events varies on both interannual and interdecadal timescales, and increases significantly after the mid 1980s. The RMDPE events happen most frequently between late June and mid July, and are generally associated with anomalous baroclinic tropospheric circulations. The supply of moisture to the southern part of central China comes in a stepping way from the outer-region of an abnormal anticyclone over the Bay of Bengal and the South China Sea. Fluxes of wave activity generated over the northeastern Tibetan Plateau converge over central China, which favors the genesis and maintenance of wave disturbances over the region. RMDPE events typically occur in tandem with a strong heating gradient formed by net heating in central China and the large-scale net cooling in the surrounding area. The occurrence of RMDPE events over central China is tied to anomalous local cyclonic circulations, topographic forcing over the northeast Tibetan Plateau, and anomalous gradients of diabatic heating between central China and the surrounding areas.

  15. Influences of subtropical jet and Tibetan Plateau on precipitation pattern in Asia : Insights from regional climate modeling

    NARCIS (Netherlands)

    Sato, Tomonori

    2009-01-01

    Large topographic features, like the Tibetan Plateau (TP) and the Rocky Mountains, have significant impacts on Earth's climate. Numerical experiments were carried out using a regional climate model in order to study the sensitivity of rainfall distribution to the TP's thermal/dynamic effects and mer

  16. Determination of regional net radiation and soil heat flux over a heterogeneous landscape of the Tibetan Plateau

    NARCIS (Netherlands)

    Ma, Y.; Su, Z.; Li, Z.; Koike, T.; Menenti, M.

    2002-01-01

    This paper explores the potential for documenting regional fields of surface energy fluxes over the Tibetan plateau using published algorithms and previously calibrated empirical formulae with data from NOAA-14 AVHRR and atmospheric data collected during the GAME-Tibet field experiment. Comparison w

  17. Determination of regional net radiation and soil heat flux over a heterogeneous landscape of the Tibetan Plateau

    NARCIS (Netherlands)

    Ma, Y.; Su, Z.; Li, Z.; Koike, T.; Menenti, M.

    2002-01-01

    This paper explores the potential for documenting regional fields of surface energy fluxes over the Tibetan plateau using published algorithms and previously calibrated empirical formulae with data from NOAA-14 AVHRR and atmospheric data collected during the GAME-Tibet field experiment. Comparison

  18. The regional distribution characteristics of aerosol optical depth over the Tibetan Plateau

    Science.gov (United States)

    Xu, Chao; Ma, Yaoming; You, Chao; Zhu, Zhikun

    2016-04-01

    The Tibetan Plateau (TP) is representative of typical clean atmospheric conditions. Aerosol optical depth (AOD) retrieved by Multi-angle Imaging SpectroRadiometer (MISR) is higher over Qaidam Basin than the rest of the TP all the year. Different monthly variation patterns of AOD are observed over the southern and northern TP, whereby the aerosol load is usually higher in the northern TP than in the southern part. The aerosol load over the northern part increases from April to June, peaking in May. The maximum concentration of aerosols over the southern TP occurs in July. Aerosols appear to be more easily transported to the main body of the TP across the northern edge rather than the southern edge. This is may be partly because the altitude is lower at the northern edge than that of the Himalayas located along the southern edge of the TP. Three-dimensional distributions of dust, polluted dust, polluted continental and smoke are also investigated based on Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data. Dust is found to be the most prominent aerosol type on the TP, and other types of aerosols affect the atmospheric environment slightly. A dividing line of higher dust occurrence in the northern TP and lower dust occurrence in the southern TP can be observed clearly at altitude of 6-8 km above sea level, especially in spring and summer. This demarcation appears around 33-35°N in the middle of the plateau, and it is possibly associated with the high altitude terrain in the same geographic location. Comparisons of CALIPSO and MISR data show that the vertical dust occurrences are consistent with the spatial patterns of AOD. The different seasonal variation patterns between the northern and southern TP are primarily driven by atmospheric circulation, and are also related to the emission characteristics over the surrounding regions.

  19. Paleoclimate Changes during the Early Oligocene in the Hoh Xil Region, Northern Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    LIU Zhifei; WANG Chengshan; Alain TRENTESAUX; ZHAO Xixi; YI Haisheng; HU Xiumian; JIN Wei

    2003-01-01

    Sedimentological, cyclic-stratigraphic, paleomagnetic, and clay-mineralogical studies on the earlyOligocene Yaxicuo Group in the Hoh Xil Basin, the largest Cenozoic sedimentary basin in the hinterland of the TibetanPlateau, provide abundant information of paleoclimate changes. A 350-m thick section in the middle-lower YaxicuoGroup was analyzed to reveal the climatic history that occurred in the Hoh Xil region during the early Oligocene interval31.30-30.35 Ma, dated with the paleomagnetic chronostratigraphy. The results indicate that arid and cold climatedominated the Hoh Xil region during the early Oligocene in general, being related to the global cooling and dryingevents that occurred in the earliest Oligocene. Within this period, relatively warm and wet climate accompanied bystrong tectonic activity occurred in the 31.05-30.75 Ma interval; while arid and cold climate and relatively inactivetectonics occurred in the 31.30-31.05 and 30.75-30.35 Ma intervals. Furthermore, spectral analyses of high-temporalresolution paleoclimatic records show orbital periods including eccentricity, obliquity, and precession. It is concludedthat paleoclimate changes during the early Oligocene in the Hoh Xil region were forced by both tectonic activity andorbital periods.

  20. Response of vegetation characteristics in the alpine meadow ecosystem to simulated temperature enhancement---A case study of permafrost regions on the Qinghai-Tibet Plateau,China%高寒草甸植被特征对模拟增温的响应--以青藏高原多年冻土区为例

    Institute of Scientific and Technical Information of China (English)

    陈翔; 彭飞; 尤全刚; 王涛; 薛娴

    2016-01-01

    Infrared heater was used to simulate temperature enhancement in the field focusing on the effects of temperature enhancement on the growth and photosynthetic characteristics of three alpine plants:Polygonum viviparum,Saussurea superb,and Carex atrofusca in order to provide basis for estimating the sensitivity and friability of the meadow ecosystem in the permafrost region on the Qinghai-Tibet Plateau,China.The results showed that the simulated warming W1(1.88 ℃)and W2(3.19 ℃)could all alter the distributing frequency and season pattern of the alpine plant species.Compared with the CK,the W1 temperature enhancement brought differ-ent changes to different plants under which the height,frequency and chlorophyll contents of the S.pulchra were de-creased but the values of the P .viviparum and C.atrofusca were increased.The W2 warming evidently in-creased the height,frequency,and chlorophyll content of the P .viviparum and C.atrofusca but significantly (P<0.05)decreased the ratio of chlorophyll a to b of the S.pulchra resulted in its decreases in the height,fre-quency,and chlorophyll content.It showed significant differences in the photosynthesis indicators among the plant species,especially among the plots.All above indicates that the warming can improve the growth and de-velopment of the grazing plants in the alpine meadow and prolong their green grass duration resulting in benefit to the livestock production but the vegetation distribution evidently variegated.%采用红外辐射灯(infrared heater)模拟气候变暖背景,研究青藏高原多年冻土区高寒草甸优势植物种珠芽蓼(Po-lygonum viviparum)、美丽风毛菊(Saussurea superb)和黑褐苔草(Carex atrofusca)的生长发育及光合特性对气候变暖的短期响应及其差异性,旨在为评价草地生态系统的敏感性和脆弱性提供科学依据.结果表明,模拟增温 W1(1.88℃)和 W2(3.19℃)均可改变高寒草甸物种分布的频度和季节分布格局,并显著影

  1. Human induced dryland degradation in Ordos Plateau, China, revealed by multilevel statistical modeling of normalized difference vegetation index and rainfall time-series

    Institute of Scientific and Technical Information of China (English)

    Jing ZHANG; JianMing NIU; Tongliga BAO; Alexander BUYANTUYEV; Qing ZHANG; JianJun DONG; XueFeng ZHANG

    2014-01-01

    Land degradation causes serious environmental problems in many regions of the world, and although it can be effectively assessed and monitored using a time series of rainfall and a normalized difference vegetation index (NDVI) from remotely-sensed imagery, dividing human-induced land degradation from vegetation dynamics due to climate change is not a trivial task. This paper presented a multilevel statistical modeling of the NDVI-rainfall relationship to detect human-induced land degradation at local and landscape scales in the Ordos Plateau of Inner Mongolia, China, and recognized that anthropogenic activities result in either positive (land restoration and re-vegetation) or negative (degradation) trends. Linear regressions were used to assess the accuracy of the multi-level statistical model. The results show that:(1) land restoration was the dominant process in the Ordos Plateau between 1998 and 2012;(2) the effect of the statistical removal of precipitation revealed areas of human-induced land degradation and improvement, the latter reflecting successful restoration projects and changes in land man-agement in many parts of the Ordos; (3) compared to a simple linear regression, multilevel statistical modeling could be used to analyze the relationship between the NDVI and rainfall and improve the accuracy of detecting the effect of human activities. Additional factors should be included when analyzing the NDVI-rainfall relationship and detecting human-induced loss of vegetation cover in drylands to improve the accuracy of the approach and elimi-nate some observed non-significant residual trends.

  2. Revealed variations of air quality in industrial development over a remote plateau of Southwest China: an application of atmospheric visibility data

    Science.gov (United States)

    Zhao, Tianliang; Liu, Di; Zheng, Xiaobo; Yang, Lexin; Gu, Xiaoping; Hu, Jun; Shu, Zhuozhi; Chang, Jiacheng; Wu, Xiasheng

    2016-12-01

    Since the 1980s, an industrial development has bloomed in China including the Yunnan-Guizhou Plateau (YGP), a remote region in Southwest China. To analyze the regional variations in air quality over YGP during the industrial development, we adopt the equivalent visibility by excluding the influence of natural factors on the observed visibility based on the meteorological data observed at 203 sites over YGP from 1980 to 2010 in this study. The YGP air quality exhibits the tremendous spatial differences in a general distribution from western good to eastern poor air quality. A similar pattern shifts seasonally in the spatial distribution with a typical seasonality of air quality over YGP between summertime low air pollution and wintertime high air pollution. The increasing and decreasing trends in visibility are mostly concentrated, respectively, in the YGP regions with high and low visibility, displaying the phenomenon of polarization in air quality change over YGP during 1980-2010. The regional mean visibility of the YGP presents a significant declining trend with change rate of -1.5 km decade-1 for air quality deterioration. The seasonal differences in visibility between summer (33.6 km) and winter (25.2 km) became obscure with the interannual change trends of visibility with stronger declines (-2.29 km decade-1) in summer and weaker decreases (-0.89 km decade-1) in winter over 1980-2010, which lead to a indistinct seasonality of air quality change over YGP. The remote YGP had experienced more frequent haze pollution, especially in the eastern plateau over 31 years. In accompany of increasing energy consumption in the industrial development, population growth is an important factor influencing the interannual change of YGP air quality. The distinct spatial distribution in the YGP terrain exerts an impact on poor air quality in lower flatlands harbored by mountainous topography with good air quality. Declined monsoon winds could meteorologically drive the air

  3. Preliminary analysis on the relationships between Tibetan Plateau NDVI change and its surface heat source and precipitation of China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Using the automatic weather station data obtained from the Tibetan Plateau (TP), the normalized dif- ference vegetation index and the monthly precipitation data of China and by the methods of correlation and composite analysis, preliminary analytical results are achieved concerning the relationships be- tween TP NDVI change and its surface heat source and precipitation of China. The results of our re- search may lead to the following conclusions: (1) A positive correlation relationship exists between TP NDVI change and its surface heat source, including the sensible heat and the latent heat. As to the correlation of the former, it is more remarkable in western TP than in eastern TP, and as to the correla- tion of the latter, however it turns out contrary. (2) With the improvement of TP vegetation, its surface heat source of every season is also mainly reinforced, especially in summer. As to the contribution of the sensible heat and the latent heat to the increment of the TP surface heat source intensity, the for- mer is comparatively more significant than the latter in winter and spring, while in summer and autumn, the two have almost the same importance. (3) The correlation coefficient between summer NDVI over TP and the corresponding period precipitation of China displays a belt distribution of "+?+" from south to north China. (4) Anomalous surface heating field over TP derived from vegetation change is probably an important factor to affect summer precipitation of China.

  4. An Experimental Simulation Method of Erosion Process on Gully Erosion in Loess Plateau in China

    Science.gov (United States)

    Gao, Jianen; Zhang, Yuanxing

    2017-04-01

    In view of simulation difficultment of the field gully erosion process because of complex of rainfall runoff erosion mechanism and gully geometry a design means and experimentation technology and its verification test were given based on similarity theory and hydrodynamic principles. The basic ideas was that the erosion process of the field erosion gully was forecast by constructing similar model. The model and antetype should be in obedience to the same physical equations of rainfall, runoff, erosion, sediment transport, bed deformation and Soil water transport. The geometric, kinematical and dynamic similarity must be obeyed for these models. The primary similarity scale relation expressions were the ones of the geometric, rainfall, flow, erosion sediment transport and soil water movement similarity etc. The similarity of the hydraulic boundary was the necessary and sufficient condition between the model and the prototype. The gully prototype is one of Majiagou of Ansai county of Yanan City of Shaanxi Province in China. Its location is 36°53'55.75"N and 109°13'39.08"E. The model experiment wan carried out in State Key Laboratory of Soil Erosion and Dry land Farming On the Loess Plateau in Institute of Soil and Water Conservation of Northwest A&F University. First soil was selected by starting velocity similar. Second, the normal and scale 10 experiment model was built under complying with the similarities of geometric, rainfall, flow, erosion production sediment transport and bed deformation etc. The model hydraulic boundary from the prototype was the factor of the test process of rainfall. The experiment results indicated that the extreme rainstorm gully erosion process of the prototype could be reappeared. The equivalent rainfall process of gully prototype were that the rainfall intensity was 1.25 mm/min and the lasting time was 508 min and precipitation was 636mmn. Both the erosion amount and the erosion gully topography of the scale model were successfully

  5. Land Desertification and it’s Control in Gonghe Basin of Qinghai Plateau, China

    Science.gov (United States)

    Zhang, D.; Gao, S.; Lu, R.

    2009-12-01

    Land desertification is an important environmental and social-economic problems that threatening people’s living conditions and impacting social sustainable development. The Gonghe basin in Qinghai Plateau is a fragile cold alpine area which is one of the places seriously threatened by desertification in China. This paper selected Gonghe basin as a study area to study land sandy desertification and its controlling measures. The engineering measures for sandy desertification control include setting clay sand barrier, Salix cheilophila sand barrier, Tamarix sand barrier, Artemisia sand barrier and straw-checker sand-barriers to fix dunes; the biological measures include closure for natural vegetation recovery, direct seeding forestation, transplanting seedlings, and so on. The combination of engineering and biologic measures can fix dunes 2~3 years earlier than the common single measure; and the costs were basically identical. A synthesized evaluation system established based on experimental results and experience in recent years indicated that the effectiveness of the four kinds of sand barrier for prevention and control of sand in study area were: Tamarix sand barrier > Artemisia sand barrier > clay sand barrier > straw-checker sand-barriers. In addition, different optimized management model can be selected according to local material and geographical place. New plants such as Salix cheilophila and Tamarix, which are available in study area, can change from dead sand barrier to live one set in proper seasons, changing engineering measure to biological one directly speeds the progress of forestation and dunes fixation. In addition, we developed new technique of deep planting Salix cheilophila and Tamarix with their long stem, which can effectively resist drought. We found that it had lower cost and higher live rate, and has a better sand prevention effect than deep planting of Poplar. Finally we choose the optimize management model as follows: Artemisia direct

  6. Changes in sediment transport in the Kuye River in the Loess Plateau in China

    Institute of Scientific and Technical Information of China (English)

    Jueyi SUI; Yun HE; Cheng LIU

    2009-01-01

    In this paper, the changes in sediment transport over 51 years from 1955 to 2006 in the Kuye River in the Loess Plateau in China are assessed. Key factors affecting sediment yield and sediment transport, such as precipitation depth, discharge, and human activities are studied. To investigate the changes in sediment yield in this watershed, a trend analysis on sediment concentration, precipitation depth, and discharge is conducted. Precipitation depths at 2 Climate Stations (CSs), as well as discharge and sediment transport at 3 Gauging Stations (GSs) are used to assess the features of sediment transport in the Kuye River. The runoff modulus (defined as the annual average discharge per unit area, L/(s'km2)) and the sediment transport modulus (defined as the annual suspended sediment transport per unit area, t/(yr km2)) are introduced in this study to assess the changes in runoff and sediment yield for this watershed. The results show that the highest average monthly discharge during the study period in the Kuye River is 66.23 m3/s in August with an average monthly sediment concentration of 88.9 kg/m3. However, the highest average monthly sediment concentration during the study period in the Kuye River is 125.34 kg/m3 and occurs in July, which has an average discharge of 42.6 m3/s that is much less than the average monthly discharge in August. It is found that both the runoff modulus and sediment transport modulus at Wenjiachuan GS on the Kuye River has a clear downward trend. During the summer season from July to August, the sediment transport modulus at Wenjiachuan GS is much higher than those at Toudaoguai and Longmen GSs on the Yellow River. The easily erodible loess in the Kuye River watershed and the sparse vegetation are responsible for the extremely high sediment yield from the Kuye River watershed. The analyses of the grain size distribution of suspended load in the Kuye River are presented. The average monthly median grain size of suspended load in the Kuye

  7. Palaeogene growth of the northeastern Tibetan Plateau: Detrital fission track and sedimentary analysis of the Lanzhou basin, NW China

    Science.gov (United States)

    Wang, Xiuxi; Deng, Lizheng; Zattin, Massimiliano; Ji, Minxiao; Li, Jijun

    2017-10-01

    The Palaeogene evolution of the northeastern Tibetan Plateau remains elusive, because of the paucity of well-dated long-lasting and continuous sedimentary records. In this work, we present a detailed detrital apatite fission track thermochronology and stratigraphic study in the Lanzhou basin, located on the eastern-most margin of northeastern Tibet, where Eocene to middle Miocene sediments are well preserved. Combining the analysis of sedimentology records and synsedimentary tectonic structures, four regional tectonic phases are deciphered (52-47 Ma, 40-32 Ma, 23-20 Ma and <16 Ma, respectively). These episodes were spaced out by three periods of tectonic stability or quiescence linked to regional relief-reduction. Our apatite fission-track data suggest that far-field stress due to the India-Asia collision had been propagated to this region since early Eocene, and the modern northeastern portion of the Tibetan Plateau has been buildup since then. Thereafter, the growth of the northeastern Tibetan Plateau was dominated by a tectonic activity/inactivity cycle until late Miocene. Thus, the regional growth history appears to have been episodic in nature during the Cenozoic.

  8. Global pollution shown by lead and cadmium contents in precipitation of polar regions and Qinghai-Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The analysis of the major ions, lead and cadmium has been performed for snow-pit samples collected from the Arctic, the Qinghai-Tibetan Plateau and the Antarctic Ice Sheet. These snow pits were excavated respectively from the snowpack in Canadian Northwest Territory (NWT) and the central Arctic, three glaciers on the Qinghai-Tibetan Plateau and surface snow along the route of the International Trans-Antarctic Expedition (ITAE). The source regions for the lead pollution of central Arctic have been identified by analyzing of stable lead isotopic ratios, meteorological and atmospheric chemistry studies. It shows that the central Arctic is still under intensive lead input, despite the fact that lead content in Greenland Ice Sheet displays a rapid decreasing since the 1970s due to US and some European countries' campaigns to reduce lead-containing gasoline-additives. This is because there are multiple lead sources for the central Arctic, including the countries that have not performed gasoline-additives reducing. The backgrounds of atmospheric aerosol compositions, as well as the concentrations of lead and cadmium in precipitation of the early 1990s, are contrasted among the Arctic, Antarctica and Qinghai-Tibetan Plateau. The measured lead content in the snowfall at the typical sites of the three regions is divided into natural (background) and anthropogenic components. It is found that natural lead concentration (mainly crustal and/or sea-salt lead) is roughly equal among the three regions (50% in Antarctic precipitation, >97% in the Arctic and the Qinghai-Tibetan Plateau ) is mainly responsible for the lead input to both polar regions and to the Qinghai-Tibetan Plateau. Lead pollution may have spread into the whole troposphere and the most remote regions on earth.

  9. Characterizations of geothermal springs along the Moxi deep fault in the western Sichuan plateau, China

    Science.gov (United States)

    Qi, Jihong; Xu, Mo; An, Chengjiao; Wu, Mingliang; Zhang, Yunhui; Li, Xiao; Zhang, Qiang; Lu, Guoping

    2017-02-01

    Abundant geothermal springs occur along the Moxi fault located in western Sichuan Province (the eastern edge of the Qinghai-Tibet plateau), highlighted by geothermal water outflow with an unusually high temperature of 218 °C at 21.5 MPa from a 2010-m borehole in Laoyulin, Kangding. Earthquake activity occurs relatively more frequently in the region and is considered to be related to the strong hydrothermal activity. Geothermal waters hosted by a deep fault may provide evidence regarding the deep underground; their aqueous chemistry and isotopic information can indicate the mechanism of thermal springs. Cyclical variations of geothermal water outflows are thought to work under the effect of solid earth tides and can contribute to understanding conditions and processes in underground geo-environments. This paper studies the origin and variations of the geothermal spring group controlled by the Moxi fault and discusses conditions in the deep ground. Flow variation monitoring of a series of parameters was performed to study the geothermal responses to solid tides. Geothermal reservoir temperatures are evaluated with Na-K-Mg data. The abundant sulfite content, dissolved oxygen (DO) and oxidation-reduction potential (ORP) data are discussed to study the oxidation-reduction states. Strontium isotopes are used to trace the water source. The results demonstrate that geothermal water could flow quickly through the Moxi fault the depth of the geothermal reservoir influences the thermal reservoir temperature, where supercritical hot water is mixed with circulating groundwater and can reach 380 °C. To the southward along the fault, the circulation of geothermal waters becomes shallower, and the waters may have reacted with metamorphic rock to some extent. Our results provide a conceptual deep heat source model for geothermal flow and the reservoir characteristics of the Moxi fault and indicate that the faulting may well connect the deep heat source to shallower depths. The

  10. Changes in extreme temperature and precipitation events in the Loess Plateau (China) during 1960-2013 under global warming

    Science.gov (United States)

    Sun, Wenyi; Mu, Xingmin; Song, Xiaoyan; Wu, Dan; Cheng, Aifang; Qiu, Bing

    2016-02-01

    In recent decades, extreme climatic events have been a major issue worldwide. Regional assessments on various climates and geographic regions are needed for understanding uncertainties in extreme events' responses to global warming. The objective of this study was to assess the annual and decadal trends in 12 extreme temperature and 10 extreme precipitation indices in terms of intensity, frequency, and duration over the Loess Plateau during 1960-2013. The results indicated that the regionally averaged trends in temperature extremes were consistent with global warming. The occurrence of warm extremes, including summer days (SU), tropical nights (TR), warm days (TX90), and nights (TN90) and a warm spell duration indicator (WSDI), increased by 2.76 (P spell duration indicator (CSDI) exhibited decreases of - 3.22 (P wet-day and extremely wet-day precipitation were not significant. Large-scale atmospheric circulation indices, such as the Western Pacific Subtropical High Intensity Index (WPSHII) and Arctic Oscillation (AO), strongly influences warm/cold extremes and contributes significantly to climate changes in the Loess Plateau. The enhanced geopotential height over the Eurasian continent and increase in water vapor divergence in the rainy season have contributed to the changes of the rapid warming and consecutive drying in the Loess Plateau.

  11. Dynamics of China's Regional Development and Pollution

    OpenAIRE

    Henri L.F.M. de Groot; Cees A. Withagen; Minliang, Zhou

    2001-01-01

    This paper addresses the existence of an Environmental Kuznets Curve for China, using a sampleof thirty regions and covering the period 1982-1997. The types of pollution included in the studyare wastewater, waste gas and solid waste. We consider the development of the sources ofpollution in a pooled cross-section analysis considering the pollution in absolute levels, in percapita terms and relative to real GDP. At intermediate levels of GDP per capita, the increase of solidand gas emissions t...

  12. China Speeds up Regional Monetary Cooperation

    Institute of Scientific and Technical Information of China (English)

    Huang Zhbin

    2009-01-01

    @@ For Asian countries which were given a hard by the financial cri-sis in late 1990s, it is now criti-cally important for them to work with each other m fighting the economic recession and export slump. China, a big country in Asia, is now taking the op-portunity to advocate regional monetary cooperation, increasing the amount of Chinese yuan held by other Asian coun-tries.

  13. Monthly Water Budget of Small Basin in Northern of Loess Plateau,China

    Institute of Scientific and Technical Information of China (English)

    HUANG Jinbai; HINOKIDANI Osamu; YASUDA Hiroshi; Kimura Reiji; ZHENG Jiyong

    2010-01-01

    The objective of this study was to analyze the water budget of a small basin in the northern of Loess Plateau. A small basin, Liudaogou in the northern Loess Plateau was chosen as the study area. The numerical calculation of surface runoff was applied to results of the field survey, and components of monthly water budget were estimated. The unit area of 1 km was selected as the index area for the estimation. A component of habitant water consumption was added to the water budget to consider the contribution of human activity. Results indicated that the water storage was negative in May, June and July while the annual amount was approximately 0.0. Evaportanspiration attained maximum in August and its annual total accounted for 74.2% of annual precipitation. Results of this study are significant for the sustainable water conservation and utilization in the northern of Loess Plateau where annual water resources are relatively deficient.

  14. Impact of anthropogenic emissions and open biomass burning on regional carbonaceous aerosols in South China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Gan, E-mail: zhanggan@gig.ac.c [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Li Jun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Xu Yue; Guo Lingli [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Tang Jianhui [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Lee, Celine S.L. [Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Liu Xiang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Yingjun [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China)

    2010-11-15

    Carbonaceous aerosols were studied at three background sites in south and southwest China. Hok Tsui in Hong Kong had the highest concentrations of carbonaceous aerosols (OC = 8.7 {+-} 4.5 {mu}g/m{sup 3}, EC = 2.5 {+-} 1.9 {mu}g/m{sup 3}) among the three sites, and Jianfeng Mountains in Hainan Island (OC = 5.8 {+-} 2.6 {mu}g/m{sup 3}, EC = 0.8 {+-} 0.4 {mu}g/m{sup 3}) and Tengchong mountain over the east edge of the Tibetan Plateau (OC = 4.8 {+-} 4.0 {mu}g/m{sup 3}, EC = 0.5 {+-} 0.4 {mu}g/m{sup 3}) showed similar concentration levels. Distinct seasonal patterns with higher concentrations during the winter, and lower concentrations during the summertime were observed, which may be caused by the changes of the regional emissions, and monsoon effects. The industrial and vehicular emissions in East, Southeast and South China, and the regional open biomass burning in the Indo-Myanmar region of Asia were probably the two major potential sources for carbonaceous matters in this region. - Anthropogenic emissions in China and open biomass burning in the Indo-Myanmar region were the two major potential sources for carbonaceous matters in South China region.

  15. Cyanobacteria in lakes on Yungui Plateau, China are assembled via niche processes driven by water physicochemical property, lake morphology and watershed land-use

    Science.gov (United States)

    Liao, Jingqiu; Zhao, Lei; Cao, Xiaofeng; Sun, Jinhua; Gao, Zhe; Wang, Jie; Jiang, Dalin; Fan, Hao; Huang, Yi

    2016-11-01

    Plateau lakes are important ecosystems with diverse ecological functions. Cyanobacteria play a key role in plateau lakes as primary producers. However, they are threatening when dense blooms occur. Identifying cyanobacteiral biogeography and the mechanism of assembly processes shaping the distribution of cyanobacteria in plateau lakes is critical for understanding cyanobacterial ecology and applying it to lake management. In the present study, the biogeographic pattern and importance of neutral and niche processes in assembly of cyanobacteria in 21 lakes on Yungui Plateau, China were examined. Results showed that cyanobacteria exhibit unique biogeographic pattern, and most of them have a narrow habitat preference in plateau lakes. They were assembled via niche processes driven by water physicochemical property, lake morphology and watershed land-use, which explained 62.4% of the biological variation. Neutral processes were not at play. Water physicochemical property (key variables - dissolved oxygen, salinity, trophic status and pH) was the most dominant driver shaping its unique biogeographic pattern. Watershed land-use especially urban land, water body and agricultural land also exhibited a strong impact on cyanobacterial distribution, followed by lake morphology. As most of the cyanobacteiral genus detected in these plateau lakes were potential toxin-producers, this study indicated that in order to protect waters from toxic-bloom in the future, reducing nutrient loading and land-use practices are two practical approaches in plateau lake management.

  16. Evaluating the eco-hydrologic impacts of soil and water conservation in the Jinghe River Basin of Loess Plateau, China, using an eco-hydrologic model

    Science.gov (United States)

    Peng, Hui; Jia, Yangwen; Tague, Christina; Slaughter, Peter

    2016-04-01

    Since the 1950s, soil and water conservation has been widely applied in the Loess Plateau in China. We examine the eco-hydrologic responses to soil and water conservation in the Jinghe River Basin of Loess Plateau in two scales - catchment scale and basin scale, using Regional Hydro-Ecologic Simulation System (RHESSys). In the catchment scale, we apply the model to disentangle the relative roles played by inter-annual variation and longer-term trends in climate drivers and re-growth following reforestation. Our model-based analysis of trends in forest water use highlights the differences in the response of control and reforested catchments to similar declines in annual precipitation in this region over the past decades. Model estimates show that while reforestation does increase vegetation water use, the impacts on streamflow are small relative to the impact of precipitation trends on streamflow, and forest water use. Results also show that the greatest impact of reforestation is likely to be on groundwater recharge but also suggest that evaporation rather than transpiration is a significant contributor to hydrologic change. In the basin scales, we applied the modified model to evaluate the impacts of soil and water conservation measures on streamflow. Results demonstrate that the soil and water conservation decreased annual streamflow by 8% (0.1 billion m3), with the largest decrease occurring in the 2000s. Model estimates also suggest that soil and water conservation engineering has greater impacts than vegetation recovery. This study offers scientific support for soil and water conservation planning and management in this region.

  17. What are the key drivers of regional differences in the water balance on the Tibetan Plateau?

    Science.gov (United States)

    Biskop, S.; Maussion, F.; Krause, P.; Fink, M.

    2015-04-01

    Lake-level fluctuations in closed basins on the Tibetan Plateau (TP) indicate climate-induced changes in the regional water balance. However, little is known about the region's key hydrological parameters, hampering the interpretation of these changes. The purpose of this study is to contribute to a more quantitative understanding of these controls. Four lakes in the south-central part of the TP were selected to analyze the spatiotemporal variations of water-balance components: Nam Co and Tangra Yumco (indicating increasing water levels), and Mapam Yumco and Paiku Co (indicating stable or slightly decreasing water levels). We present the results of an integrated approach combining hydrological modeling, atmospheric-model output and remote-sensing data. The hydrological model J2000g was adapted and extended according to the specific characteristics of closed lake basins on the TP and driven with "High Asia Refined analysis (HAR)" data at 10 km resolution for the period 2001-2010. Our results reveal that because of the small portion of glacier areas (1 to 7% of the total basin area) the contribution of glacier melt water accounts for only 14-30% of total runoff during the study period. Precipitation is found to be the principal factor controlling the water-balance in the four studied basins. The positive water balance in the Nam Co and Tangra Yumco basins was primarily related to larger precipitation amounts and thus higher runoff rates in comparison with the Paiku Co and Mapam Yumco basins. This study highlights the benefits of combining atmospheric and hydrological modeling. The presented approach can be readily transferred to other ungauged lake basins on the TP, opening new directions of research. Future work should go towards increasing the atmospheric model's spatial resolution and a better assessment of the model-chain uncertainties, especially in this region where observational data is missing.

  18. Groundwater availability of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Vaccaro, J.J.; Kahle, S.C.; Ely, D.M.; Burns, E.R.; Snyder, D.T.; Haynes, J.V.; Olsen, T.D.; Welch, W.B.; Morgan, D.S.

    2015-09-22

    The Columbia Plateau Regional Aquifer System (CPRAS) covers about 44,000 square miles of southeastern Washington, northeastern Oregon, and western Idaho. The area supports a $6-billion per year agricultural industry, leading the Nation in production of apples, hops, and eight other commodities. Groundwater pumpage and surface-water diversions supply water to croplands that account for about 5 percent of the Nation’s irrigated lands. Groundwater also is the primary source of drinking water for the more than 1.3 million people in the study area. Increasing competitive demands for water for municipal, fisheries/ecosystems, agricultural, domestic, hydropower, and recreational uses must be met by additional groundwater withdrawals and (or) by changes in the way water resources are allocated and used throughout the hydrologic system. As of 2014, most surface-water resources in the study area were either over allocated or fully appropriated, especially during the dry summer season. In response to continued competition for water, numerous water-management activities and concerns have gained prominence: water conservation, conjunctive use, artificial recharge, hydrologic implications of land-use change, pumpage effects on streamflow, and effects of climate variability and change. An integrated understanding of the hydrologic system is important in order to implement effective water-resource management strategies that address these concerns.

  19. Surface Mining and Reclamation Effects on Flood Response of Watersheds in the Central Appalachian Plateau Region

    Science.gov (United States)

    Ferrari, J. R.; Lookingbill, T. R.; McCormick, B.; Townsend, P. A.; Eshleman, K. N.

    2009-01-01

    Surface mining of coal and subsequent reclamation represent the dominant land use change in the central Appalachian Plateau (CAP) region of the United States. Hydrologic impacts of surface mining have been studied at the plot scale, but effects at broader scales have not been explored adequately. Broad-scale classification of reclaimed sites is difficult because standing vegetation makes them nearly indistinguishable from alternate land uses. We used a land cover data set that accurately maps surface mines for a 187-km2 watershed within the CAP. These land cover data, as well as plot-level data from within the watershed, are used with HSPF (Hydrologic Simulation Program-Fortran) to estimate changes in flood response as a function of increased mining. Results show that the rate at which flood magnitude increases due to increased mining is linear, with greater rates observed for less frequent return intervals. These findings indicate that mine reclamation leaves the landscape in a condition more similar to urban areas rather than does simple deforestation, and call into question the effectiveness of reclamation in terms of returning mined areas to the hydrological state that existed before mining.

  20. Surface Deformation Monitoring in Permafrost Regions of Tibetan Plateau Based on Alos Palsar Data

    Science.gov (United States)

    Chen, L. M.; Qiao, G.; Lu, P.

    2017-09-01

    The permafrost region of Qinghai-Tibet Plateau is widely distributed with the freeze/thaw processes that cause surface structural damage. The differential interferometry synthetic aperture radar (DInSAR) can detect large scale surface deformation with high precision, thus can be used to monitor the freeze/thaw processes of frozen soil area. In this paper, the surface deformation pattern of Qinghai-Tibet railway was analyzed by using the PALSAR 1.0 raw data of the ALOS satellite (L band) and 90m resolution SRTM DEM data, with the help of two-pass DInSAR method in GAMMA software, and the differential interferograms and deformation maps were obtained accordingly. Besides, the influence of temperature, topography and other factors on deformation of frozen soil were also studied. The following conclusions were obtained: there is a negative correlation between deformation and temperature, and there is a delay between the deformation change and that of temperature; deformation and elevation are positively correlated; the permafrost deformation is also affected by solar radiation that could form variable amplitude variation.

  1. Variations of stable isotopic compositions in precipitation on the Tibetan Plateau and its adjacent regions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    There is no temperature effect in the southern Tibetan Plateau and South Asia to the south of the Tanggula Mountains. Amount effect has been observed at a few sampling stations accounting for about a half of the statistical stations. There is notable temperature effect in the middle and northern Tibetan Plateau and its adjacent Central Asia to the north of the Tanggula Mountains. Because vapor directly originates from low-latitude oceans, the relative heavy ( 18O with small variation characterizes the rainfall in South Asia. A sharp depletion of the stable isotopic compositions in precipitation takes place from Kyangjin on the southern slope of the Himalayas to the Tanggula Mountains in the middle plateau. From the Tanggula Mountains to the northern Tibetan Plateau, the ( 18O in precipitation increases with increasing latitude.

  2. Study on constructive system of green cave dwelling in Loess Plateau-Interpretation with the "regional gene" theory

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This article reveals the inherent evolution adjusting mechanism of regional architecture by means of considering the concept and method of "regional gene" as the research approach of regional architecture construction system, and in the meanwhile establishes the "gene database" of regional architecture and optimum technology, on the basis of the principle of sustainable development and scientific evaluation system. In addition, this article chooses the planning of model villages of cave dwellings in Loess Plateau and the construction of ecological cave dwellings for case study to prove the feasibility of the research approach.

  3. Responses of Terrestrial Ecosystems’ Net Primary Productivity to Future Regional Climate Change in China

    Science.gov (United States)

    Zhao, Dongsheng; Wu, Shaohong; Yin, Yunhe

    2013-01-01

    The impact of regional climate change on net primary productivity (NPP) is an important aspect in the study of ecosystems’ response to global climate change. China’s ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund–Potsdam–Jena Dynamic Global Vegetation Model for China (LPJ-CN), a global dynamical vegetation model developed for China’s terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change. PMID:23593325

  4. Plant conservation priorities of Xinjiang region, China

    Science.gov (United States)

    Li, L. P.; Cui, W. H.; Wang, T.; Tian, S.; Xing, W. J.; Yin, L. K.; Abdusalih, N.; Jiang, Y. M.

    2017-02-01

    As an important region in the Silk Road, Xinjiang is getting a good chance of developing economy. However at the same time, its natural environment is facing a big challenge. To better protect the plant diversity, it is urgent to make a thorough conservation plan. With a full database of vascular and medicinal plant distributions and nature reserve plant lists and boundaries in Xinjiang of China, we analysed the plant diversity hotspots, protection gaps and proposed the plant conservation priorities of this region. Differed from the widely accepted viewpoints that lots of plants were not included in nature reserves, we found that most of the plants ( > 90%) were actually included in the current nature reserves. We believe that compared with establishing more nature reserves, improving the management of the existing ones is also important. Furthermore, the very few unprotected plants ( < 10%) were distributed mostly in the regions of Aletai, Tacheng, Zhaosu, Manasi, Qitai and Hetian which could be the future conservation priorities.

  5. Prevalence and determinants of hyperlipidemia in moderate altitude areas of the Yunnan-Kweichow plateau in Southwestern China.

    Science.gov (United States)

    Deng, Bingjun; Luo, Tingguang; Huang, Yanfei; Shen, Tianhang; Ma, Jing

    2012-03-01

    The objective of the current study was to determine the prevalence and determinants of hyperlipidemia among the populations living at moderate altitude on the Yunnan-Kweichow Plateau in Southwestern China. We randomly recruited 1415 people for this study. These subjects underwent a physical examination and a comprehensive questionnaire regarding their daily habits and diets. Furthermore, blood samples from the participants were collected for assessing the lipid profile. We found that 49.3% of participants (95% CI: 46.7-51.9%) suffered from hyperlipidemia. The prevalence in men was significantly higher than that in women (53.6% vs. 44.7%, pdine out often and consume more animal-based foods and alcohol. In addition, the hyperlipidemic men in our cohort consumed more salted food then their normolipidemic counterparts (pdining out, and BMI were found to be the main determinants of hyperlipidemia in women, whereas a prevalence of salted food was observed to be related to hyperlipidemia in men from the Yunnan-Kweichow Plateau subpopulation under study (p<0.05). The average daily energy, and protein and fat intakes of the sampled subjects were also higher than the levels set by the Chinese Recommendation Nutrient Intakes (RNI), while hyperlipidemic subjects had an even higher average daily intake of total fat, cholesterol, and lower dietary fiber compared with the normolipidemic subjects in the study group (p<0.05). In conclusion, this study reveals a higher prevalence of hyperlipidemia, hypercholesterolemia, hypertriglyceridemia, increased BMI and WHR values in men, as well as a slightly higher prevalence of low HDL-C and high LDL-C in women from Yunnan-Kweichow Plateau. The incidence of hyperlipidemia also increased with age, as did the prevalence of an abnormal TC, TG, LDL-C, and WHR in our study cohort. A high BMI, and less healthy living habits and dietary preferences thus play significant roles in the onset of hyperlipidemia.

  6. Why Does China Adopt the System of Regional Ethnic Autonomy?

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Ethnic autonomous areas have been set up throughout China where ethnic minorities live china practices regional autonomy for ethnic minorities, not other policies. It is the right choice based on China’s basic conditions.

  7. Variations in Vegetation Net Primary Production in the Qinghai-Xizang Plateau, China, from 1982 to 1999

    Energy Technology Data Exchange (ETDEWEB)

    Piao, S.; Fang, J.; He, J. [Department of Ecology, College of Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, 100871 (China)

    2006-01-15

    Vegetation net primary production (NPP) derived from a carbon model (Carnegie-Ames-Stanford Approach, CASA) and its interannual change in the Qinghai-Xizang (Tibetan) Plateau were investigated in this study using 1982-1999 time series data sets of normalized difference vegetation index (NDVI) and paired ground-based information on vegetation, climate, soil, and solar radiation. The 18-year averaged annual NPP over the plateau was 125 g C m-2 yr-1, decreasing from the southeast to the northwest, consistent with precipitation and temperature patterns. Total annual NPP was estimated between 0.183 and 0.244 Pg C over the 18 years, with an average of 0.212 Pg C (1 Pg = 1015 g). Two distinct periods (1982-1990 and 1991-1999) of NPP variation were observed, separated by a sharp reduction during 1990-1991. From 1982 to 1990, annual NPP did not show a significant trend, while from 1991 to 1999 a marked increase of 0.007 Pg C yr-2 was observed. NPP trends for most vegetation types resembled that of the whole plateau. The largest annual NPP increase during 1991-1999 appeared in alpine meadows, accounting for 32.3% of the increment of the whole region. Changes in solar radiation and temperature significantly influenced NPP variation, suggesting that solar radiation may be one of the major factors associated with changes in NPP.

  8. Regional Inequalities in Contemporary China Measured by GDP and Consumption

    OpenAIRE

    Z Zhang; Yao, S.

    2001-01-01

    This paper presents a comprehensive picture of China?s regional inequality from 1952 to 1999 using newly released data on consumption and gross domestic product (GDP) at the provincial level. Although there are many studies on regional inequality in China, this paper is the first attempt to evaluate regional inequalities before and after the economic reforms for a time span of almost half a century. Our results show that inter-regional inequality widens over time, either measured by per capit...

  9. Geologic Setting and Hydrogeologic Units of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Kahle, Sue C.; Olsen, Theresa D.; Morgan, David S.

    2009-01-01

    The Columbia Plateau Regional Aquifer System (CPRAS) covers approximately 44,000 square miles of northeastern Oregon, southeastern Washington, and western Idaho. The area supports a $6 billion per year agricultural industry, leading the Nation in production of apples and nine other commodities (State of Washington Office of Financial Management, 2007; U.S. Department of Agriculture, 2007). Groundwater availability in the aquifers of the area is a critical water-resource management issue because the water demand for agriculture, economic development, and ecological needs is high. The primary aquifers of the CPRAS are basalts of the Columbia River Basalt Group (CRBG) and overlying basin-fill sediments. Water-resources issues that have implications for future groundwater availability in the region include (1) widespread water-level declines associated with development of groundwater resources for irrigation and other uses, (2) reduction in base flow to rivers and associated effects on temperature and water quality, and (3) current and anticipated effects of global climate change on recharge, base flow, and ultimately, groundwater availability. As part of a National Groundwater Resources Program, the U.S. Geological Survey began a study of the CPRAS in 2007 with the broad goals of (1) characterizing the hydrologic status of the system, (2) identifying trends in groundwater storage and use, and (3) quantifying groundwater availability. The study approach includes documenting changes in the status of the system, quantifying the hydrologic budget for the system, updating the regional hydrogeologic framework, and developing a groundwater-flow simulation model for the system. The simulation model will be used to evaluate and test the conceptual model of the system and later to evaluate groundwater availability under alternative development and climate scenarios. The objectives of this study were to update the hydrogeologic framework for the CPRAS using the available

  10. Evapotranspiration and Soil Moisture Balance for Vegetative Restoration in a Gully Catchment on the Loess Plateau, China

    Institute of Scientific and Technical Information of China (English)

    HUANG Yi-Long; CHEN Li-Ding; FU Bo-Jie; ZHANG Li-Ping; WANG Yan-Lin

    2005-01-01

    Evapotranspiration, soil moisture balance and the dynamics in a gully catchment of the Loess Plateau in China were determined with 6 land use treatments including natural grassland, shrubs (Caragana microphylla), two woodlands (Prunus armeniaca var. ansu and Pinus tabulaeformis), cultivated fallow, and farmland (Triticum aestivum L.) in order to obtain a better understanding of soil moisture balance principles and to improve vegetation restoration efficiency for ecological rebuilding on the plateau. Average runoff from cultivated fallow was very high, reaching 10.3% of the seasonal rainfall. Evapotranspiration under T. aestivum was not significantly different from natural grasslands. Compared with natural grass, evapotranspiration was significantly greater (P < 0.05) in 2002 and there was an increase in soil moisture depleted in the 1-3 m soil under P. armeniaca, P. tabulaeformis and C. microphylla. During the two years of the study the average soil moisture (0-100 cm soil profile) of T. aestivum was generally the highest, with P. armeniaca, P. tabulaeformis and C. microphylla usually the lowest. Thus, according to the soil moisture balance principle for this area the planned reforestation project was not ecologically reasonable. Reducing human disturbance and restoration with grass could be more effective.

  11. Microplastic pollution of lakeshore sediments from remote lakes in Tibet plateau, China.

    Science.gov (United States)

    Zhang, Kai; Su, Jing; Xiong, Xiong; Wu, Xiang; Wu, Chenxi; Liu, Jiantong

    2016-12-01

    Tibetan Plateau is known as the world's third pole, which is characterized by a low population density with very limited human activities. Tibetan Plateau possesses the greatest numbers of high-altitude inland lakes in the world. However, no information is currently available on the characteristic of microplastic pollution in those lakes within this remote area. In this work, lakeshore sediments from four lakes within the Siling Co basin in northern Tibet were sampled and examined for microplastics (plastic products. Polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyvinyl chloride were identified from the microplastic samples using laser Raman spectroscopy, and oxidative and mechanical weathering textures were observed on the surface of microplastics using scanning electron microscope. These results demonstrate the presence of microplastics even for inland lakes in remote areas under very low human impact, and microplastic pollution can be a global issue.

  12. Soil carbon fractions and enzyme activities under different vegetation types on the Loess Plateau of China

    OpenAIRE

    Zhang, Haixin; Zeng, Quanchao; An, Shaoshan; Dong, Yanghong; Darboux, Frédéric

    2016-01-01

    Vegetation restoration was effective way of protecting soil erosion and water conservation on the Loess Plateau. Carbon fractions and enzyme activities were sensitive parameters for assessment of soil remediation through revegetation. Forest, forest steppe and grassland soils were collected at 0–5 cm and 5–20 cm soil layers in Yanhe watershed, Shaanxi Province. Urease, sucrase, alkaline phosphatase, soil organic carbon (SOC), microbial biomass carbon (MBC), easily ox...

  13. Complex responses of spring alpine vegetation phenology to snow cover dynamics over the Tibetan Plateau, China.

    Science.gov (United States)

    Wang, Siyuan; Wang, Xiaoyue; Chen, Guangsheng; Yang, Qichun; Wang, Bin; Ma, Yuanxu; Shen, Ming

    2017-09-01

    Snow cover dynamics are considered to play a key role on spring phenological shifts in the high-latitude, so investigating responses of spring phenology to snow cover dynamics is becoming an increasingly important way to identify and predict global ecosystem dynamics. In this study, we quantified the temporal trends and spatial variations of spring phenology and snow cover across the Tibetan Plateau by calibrating and analyzing time series of the NOAA AVHRR-derived normalized difference vegetation index (NDVI) during 1983-2012. We also examined how snow cover dynamics affect the spatio-temporal pattern of spring alpine vegetation phenology over the plateau. Our results indicated that 52.21% of the plateau experienced a significant advancing trend in the beginning of vegetation growing season (BGS) and 34.30% exhibited a delaying trend. Accordingly, the snow cover duration days (SCD) and snow cover melt date (SCM) showed similar patterns with a decreasing trend in the west and an increasing trend in the southeast, but the start date of snow cover (SCS) showed an opposite pattern. Meanwhile, the spatial patterns of the BGS, SCD, SCS and SCM varied in accordance with the gradients of temperature, precipitation and topography across the plateau. The response relationship of spring phenology to snow cover dynamics varied within different climate, terrain and alpine plant community zones, and the spatio-temporal response patterns were primarily controlled by the long-term local heat-water conditions and topographic conditions. Moreover, temperature and precipitation played a profound impact on diverse responses of spring phenology to snow cover dynamics. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Characteristics of the precipitation recycling ratio and its relationship with regional precipitation in China

    Science.gov (United States)

    Hua, Lijuan; Zhong, Linhao; Ke, Zongjian

    2017-02-01

    A dynamic recycling model (DRM) with an analytical moisture trajectory tracking method, together with Japan Meteorological Agency 25-year reanalysis data, is used to study the regional precipitation recycling process across China, by calculating the regional recycling ratio ( ρ r ) at the daily time scale during 1979-2010. The distribution of ρ r shows that, in western China, especially the Tibetan Plateau and its surrounding areas, precipitation is strongly dependent on the recycling process associated with regional evaporation. In Southeast China, however, the contribution from the recycling processes is much smaller due to the influence of the summer monsoon. A precipitation threshold value of about 4 mm/day is obtained from detailed analysis of both extreme and all-range ρ r years. According to this threshold, China is classified into three types of sub-regions: low-precipitation sub-regions (mainly in the northwest), high-precipitation sub-regions (mainly in the south), and medium-precipitation sub-regions (mainly in the northeast). It is found that ρ r correlates positively with precipitation, as well as convective precipitation ( P CP) and large-scale precipitation ( P LP) in the low-precipitation sub-regions. However, negative ρ r ˜ P LP correlations are found in the high-precipitation sub-regions and nonsignificant correlations exist in the medium-precipitation sub-regions. As P CP is mainly locally generated due to mid-latitude mesoscale systems and the cumulus parameterization used in producing the reanalysis, the recycling ratio positively correlates to the ratio P CP/ P LP in almost all sub-regions, particularly in the Tibetan Plateau and its surrounding areas. The correlation between radiation flux and ρ r suggests more net radiation supports more evaporation and higher ρ r , especially in the high-precipitation sub-regions. The influence of clouds on shortwave radiation is crucial, since evaporation is suppressed when the amount of cloudiness

  15. Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau

    Science.gov (United States)

    van Wijk, Esmee M.; Rintoul, Stephen R.; Ronai, Belinda M.; Williams, Guy D.

    2010-05-01

    The fine-scale circulation around the Heard and McDonald Islands and through the Fawn Trough, Kerguelen Plateau, is described using data from three high-resolution CTD sections, Argo floats and satellite maps of chlorophyll a, sea surface temperature (SST) and absolute sea surface height (SSH). We confirm that the Polar Front (PF) is split into two branches over the Kerguelen Plateau, with the NPF crossing the north-eastern limits of our survey carrying 25 Sv to the southeast. The SPF was associated with a strong eastward-flowing jet carrying 12 Sv of baroclinic transport through the deepest part of Fawn Trough (relative to the bottom). As the section was terminated midway through the trough this estimate is very likely to be a lower bound for the total transport. We demonstrate that the SPF contributes to the Fawn Trough Current identified by previous studies. After exiting the Fawn Trough, the SPF crossed Chun Spur and continued as a strong north-westward flowing jet along the eastern flank of the Kerguelen Plateau before turning offshore between 50°S and 51.5°S. Measured bottom water temperatures suggest a deep water connection between the northern and southern parts of the eastern Kerguelen Plateau indicating that the deep western boundary current continues at least as far north as 50.5°S. Analysis of satellite altimetry derived SSH streamlines demonstrates a southward shift of both the northern and southern branches of the Polar Front from 1994 to 2004. In the direct vicinity of the Heard and McDonald islands, cool waters of southern origin flow along the Heard Island slope and through the Eastern Trough bringing cold Winter Water (WW) onto the plateau. Complex topography funnels flow through canyons, deepens the mixed layer and increases productivity, resulting in this area being the preferred foraging region for a number of satellite-tracked land-based predators.

  16. Analysis of land surface parameters and turbulence characteristics over the Tibetan Plateau and surrounding region

    Science.gov (United States)

    Wang, Yinjun; Xu, Xiangde; Liu, Huizhi; Li, Yueqing; Li, Yaohui; Hu, Zeyong; Gao, Xiaoqing; Ma, Yaoming; Sun, Jihua; Lenschow, Donald H.; Zhong, Shiyuan; Zhou, Mingyu; Bian, Xindi; Zhao, Ping

    2016-08-01

    Based on the results from 11 flux sites during the third Tibetan Plateau (TP) Experiment (TIPEX III), land surface parameters and the turbulence characteristics of the atmospheric surface layer over the TP and surrounding region are analyzed. Monin-Obukhov similarity theory has been used to calculate the aerodynamic roughness length z0m and the excess resistance to heat transfer kB- 1 = ln(z0m/z0h), and the factors that cause variations of z0m and kB- 1 are investigated. The main drivers for the diurnal variations of surface albedo (α) at different sites are solar elevation, solar radiation, and soil moisture. The eddy correlation method is utilized to inversely calculate bulk transfer coefficients for momentum (CD) and heat (CH) at different sites. The relationships between CD and CH and the wind speed at 10 m follow a power law for unstable stratification. For stable stratification, both CD and CH increase with increasing wind speed when wind speed is less than 5 m/s. Diurnal variations of turbulent fluxes are compared at different sites, and the relationships between turbulent fluxes and other variables are analyzed. Wind speed variance normalized by the friction velocity (σu/u*, σv/u*, σw/u*) for neutral stratification (Cu1, Cv1, Cw1), and temperature and humidity variance normalized by a temperature and humidity scale (σT/T*, σq/q*) under free convection (z/L < -0.1) (CT, Cq) are fitted with similarity relations. The differences in similarity constants (Cu1, Cv1, Cw1, CT, Cq) at different sites are discussed. For stable stratification, cases are divided into weakly stable conditions and intermittent turbulence, and the critical values for these two states are determined. Shear and buoyancy terms in the turbulence kinetic energy equation for different stratifications are analyzed.

  17. Climatic features of atmospheric heat source/sink over theQinghai-Xizang Plateau in 35 years and its relation torainfall in China

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Ping

    2001-01-01

    [1]Yeh, T. C., Gao, Y. X., The Meteorology of the Qinghai-Xizang Plateau (in Chinese), Beijing: Science Press, 1979, 2-59.[2]Ji, G. L., Yao, L. C., Yuan, F. M. et al., Characteristics of surface and atmospheric heating fields over Qinghai-Xizang Plateau during the winter in 1982, Science in China, Ser. B, 1986, 29(8): 876-888.[3]Chen. L. X., Reiter, E. R., Feng, Z. Q., The atmospheric heat source over the Tibetan plateau: May-August 1979. Mon.Wea. Rev., 1985, 113(10): 1771-1790.[4]Yanai, M., Li, C., Song, Z. S., Seasonal heating of the Tibetan plateau and its effects on the evolution of the Asian summer monsoon, Journal of the Meteorological Society of Japan, 1992, 70(1): 319-350.[5]Zhao, P., Chen, L. X., The climate characteristics of surface turbulent exchange coefficients and surface heat source over the Qinghai-Tibetan plateau, Acta Meteorologica Sinica, 2000, 14(1): 13-29.[6]Zhao, P., Chen, L. X., The calculation of solar albedo and radiation balance and the analysis of their climate characteristics over the Qinghai-Tibetan plateau, Advances in Atmospheric Sciences, 2000, 17(1): 140-156.[7]Fu, C. B., Wang, Q., The definition and detection of the abrupt climatic change, Scientia Atmospheria Sinica (in Chinese),1992. 16 (4): 482-493.

  18. China and regional conflictivity: a panoramic look

    Directory of Open Access Journals (Sweden)

    Augusto Soto

    2003-09-01

    Full Text Available From the Chinese-American détente of the 1980s until present-day China, we should examine and compare the challenges of a de-ideologised environment in a new framework of confrontation with the United States. An attentive look at the map will verify that several of China’s neighbouring countries have drawn closer to Washington in the context of its new doctrine of security, and they have even accepted American troops, advisers and economic aid. In relation to its neighbours, Beijing finds itself in a strategic position in which its northwestern flank is more favourable than its eastern one. On the other hand, Beijing has displayed a promising relationship with regional organisations, like the Regional Forum of ASEAN and the Shanghai Cooperation Organization. Nevertheless, it has little real maneuverability today in managing the Taiwan and North Korean conflicts.

  19. Characteristics of Soil and Organic Carbon Loss Induced by Water Erosion on the Loess Plateau in China.

    Science.gov (United States)

    Li, Zhongwu; Nie, Xiaodong; Chang, Xiaofeng; Liu, Lin; Sun, Liying

    2016-01-01

    Soil erosion has been a common environmental problem in the Loess Plateau in China. This study aims to better understand the losses of soil organic carbon (SOC) induced by water erosion. Laboratory-simulated rainfall experiments were conducted to investigate the characteristics of SOC loss induced by water erosion. The applied treatments included two rainfall intensities (90 and 120 mm h-1), four slope gradients (10°, 15°, 20°, and 25°), and two typical soil types- silty clay loam and silty loam. Results showed that the sediment OC enrichment ratios (ERoc) in all the events were relative stable with values ranged from 0.85 to1.21 and 0.64 to 1.52 and mean values of 0.98 and 1.01 for silty clay loam and silty loam, respectively. Similar to the ERoc, the proportions of different sized particles in sediment showed tiny variations during erosion processes. No significant correlation was observed between ERoc values and the proportions of sediment particles. Slope, rainfall intensity and soil type almost had no impact on ERoc. These results indicate that the transportation of SOC during erosion processes was nonselective. While the mean SOC loss rates for the events of silty clay loam and silty loam were 0.30 and 0.08 g m-2 min-1, respectively. Greater differences in SOC loss rates were found in events among different soil types. Meanwhile, significant correlations between SOC loss and soil loss for all the events were observed. These results indicated that the amount of SOC loss was influenced primarily by soil loss and the SOC content of the original soil. Erosion pattern and original SOC content are two main factors by which different soils can influence SOC loss. It seems that soil type has a greater impact on SOC loss than rainfall characteristics on the Loess Plateau of China. However, more kinds of soils should be further studied due to the special formation processes in the Loess Plateau.

  20. Analysis of baseflow index based hydrological model in Upper Wei River basin on the Loess Plateau in China

    OpenAIRE

    Liu, D; Chang, J.; Tian, F.; Q. Huang; X. Meng

    2015-01-01

    The baseflow is the drainage from the groundwater and soil water to the streamflow. As one important source of the streamflow, the baseflow could be the main source of the streamflow in the dry season. The Wei River, located in the semi-arid region of the Loess Plateau which is overlain by deep and loose soil, is the largest tributary of the Yellow River. According to former research, most of the streamflow in the dry season in the headwater of the Yellow River is baseflow. For the whole Yell...

  1. Simulation of oasis breeze circulation in the arid region of the Northwestern China

    Institute of Scientific and Technical Information of China (English)

    Lü; Shihua

    2004-01-01

    [1]Su, C. X., Hu, Y. Q., Microclimatic characteristics and "cold island effect" of oasis in Hexi region, Atmospheric Sciences (in Chinese), 1987, 11(4): 390-396.[2]Su, C. X., Hu, Y. Q., The cold island effect of oasis and lake,Chinese Science Bulletin, 1988, 33(12): 1023-1026.[3]Hu, Y. Q., Gao, Y. X., Wang, J. M., Some research results of HEIFE test, Plateau Meteorology (in Chinese), 1994, 13(3): 225-236.[4]Lu, S. H., Cheng, Y. C., The simulation of oasis and desert surface influence on atmospheric boundary, Journal of Desert Research (in Chinese), 1995, 15(2): 116-123.[5]Lu, S. H., Cheng, Y. C., The influence of northwest China afforestation on regional climate China, Plateau Meteorology (in Chinese), 1999, 18(3): 416-424.[6]Zhang, Q., Wei, G. A., Huang, R. H. et al., Impact of oasis on the atmosphere hydrological cycle over desert or Gobi near it--a study by Dunhuang experiment, Progress in Natural Science (in Chinese), 2002, 12: 170-175.[7]Gao, Y. H., Lii, S. H., Numerical simulation of local climate effect of heterogeneous underlying surface, Plateau Meteorology (in Chinese), 2001, 20(4): 354-361.[8]Gao, Y. H., Lu, S. H., Numerical simulation of influence of different oasis distribution on regional climate, Journal of Desert Research (in Chinese), 2001, 21(2): 108-115.

  2. Black carbon aerosol in winter northeastern Qinghai-Tibetan Plateau, China: the effects from South Asia pollution

    Directory of Open Access Journals (Sweden)

    Q. Y. Wang

    2015-05-01

    Full Text Available Black carbon (BC aerosol at high-altitude Qinghai-Tibetan Plateau has potential effects on the regional climate and hydrological cycle. An intensive measurement campaign was conducted at Qinghai Lake (∼ 3200 a.s.l. at the edge of the northeastern Qinghai-Tibetan Plateau during winter using a ground-based single particle soot photometer (SP2 and a photoacoustic extinctiometer (PAX. The average BC concentration and number fraction of coated BC were found to be 160 ± 190 ng m-3 and 59.3% for the entire campaign, respectively. Significant enhancements of BC loadings and number fraction of coated BC were observed during pollution episode, with an average value of 390 ng m-3 and 64.6%, respectively. The mass size distribution of BC particles showed lognormal distribution with a peak diameter of ∼ 187 nm regardless of the pollution level. Five-day backward trajectory analysis combined with the fire counts map suggests that the biomass burning air masses from North India contributing to the increased BC loadings during the campaign. The potential source contribution function (PSCF model further proves that North India is an important potential region influencing northeastern Qinghai-Tibetan Plateau during the pollution episode. The BC mass absorption cross section (MACBC at λ = 532 nm was slightly larger during pollution episode (10.2 m2 g-1 than in clean days (8.9 m2 g-1, likely due to the higher mixing state of BC with other chemical components during pollution episode. The number fraction of coated BC particles showed positive correlation with light absorption, suggesting that the increase of coated BC particles will enhance the light absorption. The estimated BC direct radiative forcing was +0.93 W m-2 for pollution episode, which is 2 times larger than that in clean days. Our study provides insight into the potential climatic impacts of BC aerosol transported to the Qinghai-Tibetan Plateau from South Asian regions, and is also useful for

  3. Regional characterization of Western China-II

    Energy Technology Data Exchange (ETDEWEB)

    Randall, G.E.; Hartse, H.E.; Phillips, W.S.; Taylor, S.R. [Los Alamos National Lab., NM (United States). Geophysics Group

    1996-10-01

    As part of the CTBT Research and Development regional characterization effort, geological, geophysical, and seismic data are being assembled and organized for inclusion in a knowledge base for China. The authors have continued their analysis using data form the station WMQ of the Chinese Digital Seismic Network (CDSN) and the IRIS station AAK. They are also acquiring and analyzing data from stations that are designated as (or near a designated) primary or secondary CTBT monitoring station. Regional seismograms are being analyzed to construct travel time curves, velocity models, attenuation characteristics, and to quantify regional propagation effects such as phase blockages. Using locations from the USGS Preliminary Determination of Epicenters (PDE) they have identified Pn, Pg, Sn, and Lg phases, constructed travel time curves, and estimated apparent velocities using linear regression. Amplitudes for the seismic phases have been measured using bandpassed waveforms and a series of magnitude relations have been determined for Western China. Studies of path specific propagation efficiency of the seismic phases have mapped blockages and also identified a possible set of observations that can be used to identify intermediate depth (> 100 im) seismic events in the Pamir-Hindu Kush seismic zone. Chinese seismicity catalogs from the USGS and Chinese State Seismological Bureau (SSB) are being used to identify and obtain seismic data (including mine seismicity) and information for lower magnitude events. Clustering analysis has been used to identify seismicity clusters in space with origin times that are distributed during daylight hours which suggest mining operations. These clusters are being investigated with imagery to attempt to identify precise mine locations.

  4. Sandy Desertification Status and its Driving Mechanism in North Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    DONG Yuxiang

    2004-01-01

    As the main body of Qinghai-Tibetan Plateau, North Tibet Plateau is one of three major sandy desertification regions in China and also a representative sandy desertification zone of Qinghai-Tibet Plateau. Accordingly, it is an important region for the study of recent sandy desertification processes and formation mechanism. From such aspects as desertified land types, areas and distributions etc., this paper analyses in detail the sandy desertification status on North Tibet Plateau,and qualitatively and quantitatively deals with the main factors that affect recent sandy desertification processes and the driving mechanism. Research results show that North Tibet Plateau is an important sandy desertification region in China characterized with large desertified land areas, diversified types,high severity, extensive distributions and serious damages. Sandy desertification occurrence and development resulted from combined effects of natural factors, anthropogenic factors, natural processes and man-made processes, of which climatic change is the main driving force.

  5. A model to determine the lake nutrient standards for drinking water sources in Yunnan-Guizhou Plateau Ecoregion, China

    Institute of Scientific and Technical Information of China (English)

    Danfeng Ji; Beidou Xi; Jing Su; Shouliang Huo; Li He; Hongliang Liu; Queping Yang

    2013-01-01

    Lake eutrophication (LE) has become an increasingly severe environmental problem recently.However,there has been no nutrient standard established for LE control in many developing countries such as China.This study proposes a structural equation model to assist in the establishment of a lake nutrient standard for drinking water sources in Yunnan-Guizhou Plateau Ecoregion (Yungui Ecoregion),China.The modeling results indicate that the most predictive indicator for designated use-attainment is total phosphorus (TP) (total effect =-0.43),and chlorophyll a (Chl-a) is recommended as the second important indicator (total effect =-0.41).The model is further used for estimating the probability of use-attainment associated with lake water as a drinking water source and various levels of candidate criteria (based on the reference conditions and the current environmental quality standards for surface water).It is found that these candidate criteria cannot satisfy the designated 100% use-attainment.To achieve the short-term target (85% attainment of the designated use),TP and Chl-a values ought to be less than 0.02 mg/L and 1.4 tg/L,respectively.When used as a long-term target (90% or greater attainment of the designated use),the TP and Chl-a values are suggested to be less than 0.018 mg/L and 1 μg/L,respectively.

  6. Sedimentary record of regional deformation and dynamics of the thick-skinned southern Puna Plateau, central Andes (26-27°S)

    Science.gov (United States)

    Zhou, Renjie; Schoenbohm, Lindsay M.; Sobel, Edward R.; Carrapa, Barbara; Davis, Donald W.

    2016-01-01

    The Puna Plateau, adjacent Eastern Cordillera and the Sierras Pampeanas of the central Andes are largely characterized by thick-skinned, basement-involved deformation. The Puna Plateau hosts ∼N-S trending bedrock ranges bounded by deep-seated reverse faults and sedimentary basins. We contribute to the understanding of thick-skinned dynamics in the Puna Plateau by constraining regional kinematics of the poorly understood southern Puna Plateau through a multidisciplinary approach. On the southeastern plateau, sandstone modal composition and detrital zircon U-Pb and apatite fission-track data from Cenozoic strata indicate basin accumulation during the late Eocene to early Oligocene (∼38-28 Ma). Provenance analysis reveals the existence of a regional-scale basin covering the southern Puna Plateau during late Eocene to early Oligocene time (∼38-28 Ma) that was sourced from both the western plateau and the eastern plateau margin and had a depocenter located to the west. Petrographic and detrital zircon U-Pb data reveal erosion of proximal western and eastern sources after ∼12 Ma, in mid-late Miocene time. This indicates that the regional basin was compartmentalized into small-scale depocenters by the growth of basement-cored ranges continuing into the late Miocene (∼12-8 Ma). We suggest that the Cenozoic history of the southern Puna Plateau records the formation of a regional basin that was possibly driven by lithospheric flexure during the late Eocene to early Oligocene, before the growth of distributed basement-cored ranges starting as early as the late Oligocene.

  7. A New Technique for Composting Livestock Manure on the Cold Qinghai-Tibet Plateau, China

    Directory of Open Access Journals (Sweden)

    FAN Yue

    2014-08-01

    Full Text Available Livestock manure compositing on the cold Qinghai-Tibet Plateau is a feasible way to utilize manure while alleviating negative en-vironmental effects. In order to overcome unfavorable factors of cold temperature and shortage of manpower for composting operation, we de-veloped a new technique for composting livestock manure on the Qinghai-Tibet plateau:static ventilation-double-layer film insulation and studied the effect of it. The static ventilation had been achieved by ventilation pipes implanted in compost stacks while double-layer film mulching had prevented heat loss from composting process. Composting trials showed that compared with pile turning over, the static ventila-tion pipes significantly shortened the time for temperature rise and reduced the temperature difference between interior and outer layers of compost stacks, and thus speeded up the composting process meanwhile reducing losses of nutrients during composting. The double-layer film mulching further helped maintain the temperature of compost stacks. By this new technique, the operation of overturning compost stacks was not a necessity for composting livestock manure. Adding phosphorus fertilizers to manure for composting also helped to increase tempera-ture but this had a possibility to increase losses of nitrogen and organic matters from composts.

  8. Trends in temperature extremes over nine integrated agricultural regions in China, 1961-2011

    Science.gov (United States)

    Wu, Xushu; Wang, Zhaoli; Zhou, Xiaowen; Lai, Chengguang; Chen, Xiaohong

    2016-06-01

    By characterizing the patterns of temperature extremes over nine integrated agricultural regions (IARs) in China from 1961 to 2011, this study performed trend analyses on 16 extreme temperature indices using a high-resolution (0.5° × 0.5°) daily gridded dataset and the Mann-Kendall method. The results show that annually, at both daytime and nighttime, cold extremes significantly decreased but warm extremes significantly increased across all IARs. Overall, nighttimes tended to warm faster than daytimes. Diurnal temperature ranges (DTR) diminished, apart from the mid-northern Southwest China Region and the mid-Loess Plateau Region. Seasonally, DTR widely diminished across all IARs during the four seasons except for spring. Higher minimum daily minimum temperature (TNn) and maximum daily maximum temperature (TXx), in both summer and winter, were recorded for most IARs except for the Huang-Huai-Hai Region; in autumn, all IARs generally encountered higher TNn and TXx. In all seasons, warming was observed at daytime and nighttime but, again, nighttimes warmed faster than daytimes. The results also indicate a more rapid warming trend in Northern and Western China than in Southern and Eastern China, with accelerated warming at high elevations. The increases in TNn and TXx might cause a reduction in agriculture yield in spring over Northern China, while such negative impact might occur in Southern China during summer. In autumn and winter, however, the negative impact possibly occurred in most of the IARs. Moreover, increased TXx in the Pearl River Delta and Yangtze River Delta is possibly related to rapid local urbanization. Climatically, the general increase in temperature extremes across Chinese IARs may be induced by strengthened Northern Hemisphere Subtropical High or weakened Northern Hemisphere Polar Vortex.

  9. Warmer and Wetter Soil Stimulates Assimilation More than Respiration in Rainfed Agricultural Ecosystem on the China Loess Plateau: The Role of Partial Plastic Film Mulching Tillage.

    Science.gov (United States)

    Gong, Daozhi; Hao, Weiping; Mei, Xurong; Gao, Xiang; Liu, Qi; Caylor, Kelly

    2015-01-01

    Effects of agricultural practices on ecosystem carbon storage have acquired widespread concern due to its alleviation of rising atmospheric CO2 concentrations. Recently, combining of furrow-ridge with plastic film mulching in spring maize ecosystem was widely applied to boost crop water productivity in the semiarid regions of China. However, there is still limited information about the potentials for increased ecosystem carbon storage of this tillage method. The objective of this study was to quantify and contrast net carbon dioxide exchange, biomass accumulation and carbon budgets of maize (Zea maize L.) fields under the traditional non-mulching with flat tillage (CK) and partial plastic film mulching with furrow-ridge tillage (MFR) on the China Loess Plateau. Half-hourly net ecosystem CO2 exchange (NEE) of both treatments were synchronously measured with two eddy covariance systems during the growing seasons of 2011 through 2013. At same time green leaf area index (GLAI) and biomass were also measured biweekly. Compared with CK, the warmer and wetter (+1.3°C and +4.3%) top soil at MFR accelerated the rates of biomass accumulation, promoted greater green leaf area and thus shortened the growing seasons by an average value of 10.4 days for three years. MFR stimulated assimilation more than respiration during whole growing season, resulting in a higher carbon sequestration in terms of NEE of -79 gC/m2 than CK. However, after considering carbon in harvested grain (or aboveground biomass), there is a slight higher carbon sink (or a stronger carbon source) in MFR due to its greater difference of aboveground biomass than that of grain between both treatments. These results demonstrate that partial plastic film mulched furrow-ridge tillage with aboveground biomass exclusive of grain returned to the soil is an effective way to enhance simultaneously carbon sequestration and grain yield of maize in the semiarid regions.

  10. Warmer and Wetter Soil Stimulates Assimilation More than Respiration in Rainfed Agricultural Ecosystem on the China Loess Plateau: The Role of Partial Plastic Film Mulching Tillage.

    Directory of Open Access Journals (Sweden)

    Daozhi Gong

    Full Text Available Effects of agricultural practices on ecosystem carbon storage have acquired widespread concern due to its alleviation of rising atmospheric CO2 concentrations. Recently, combining of furrow-ridge with plastic film mulching in spring maize ecosystem was widely applied to boost crop water productivity in the semiarid regions of China. However, there is still limited information about the potentials for increased ecosystem carbon storage of this tillage method. The objective of this study was to quantify and contrast net carbon dioxide exchange, biomass accumulation and carbon budgets of maize (Zea maize L. fields under the traditional non-mulching with flat tillage (CK and partial plastic film mulching with furrow-ridge tillage (MFR on the China Loess Plateau. Half-hourly net ecosystem CO2 exchange (NEE of both treatments were synchronously measured with two eddy covariance systems during the growing seasons of 2011 through 2013. At same time green leaf area index (GLAI and biomass were also measured biweekly. Compared with CK, the warmer and wetter (+1.3°C and +4.3% top soil at MFR accelerated the rates of biomass accumulation, promoted greater green leaf area and thus shortened the growing seasons by an average value of 10.4 days for three years. MFR stimulated assimilation more than respiration during whole growing season, resulting in a higher carbon sequestration in terms of NEE of -79 gC/m2 than CK. However, after considering carbon in harvested grain (or aboveground biomass, there is a slight higher carbon sink (or a stronger carbon source in MFR due to its greater difference of aboveground biomass than that of grain between both treatments. These results demonstrate that partial plastic film mulched furrow-ridge tillage with aboveground biomass exclusive of grain returned to the soil is an effective way to enhance simultaneously carbon sequestration and grain yield of maize in the semiarid regions.

  11. [Comparison on the methods for spatial interpolation of the annual average precipitation in the Loess Plateau region].

    Science.gov (United States)

    Yu, Yang; Wei, Wei; Chen, Li-ding; Yang, Lei; Zhang, Han-dan

    2015-04-01

    Based on 57 years (1957-2013) daily precipitation datasets of the 85 meteorological stations in the Loess Plateau region, different spatial interpolation methods, including ordinary kriging (OK), inverse distance weighting (IDW) and radial-based function (RBF), were conducted to analyze the spatial variation of annual average precipitation regionally. Meanwhile, the mean absolute error (MAE), the root mean square error (RMSE), the accuracy (AC) and the Pearson correlation coefficient (R) were compared among the interpolation results in order to quantify the effects of different interpolation methods on spatial variation of the annual average precipitation. The results showed that the Moran's I index was 0.67 for the 57 years annual average precipitation in the Loess Plateau region. Meteorological stations exhibited strong spatial correlation. The validation results of the 63 training stations and 22 test stations indicated that there were significant correlations between the training and test values among different interpolation methods. However, the RMSE (IDW = 51.49, RBF = 43.79) and MAE (IDW = 38.98, RBF = 34.61) of the IDW and the RBF showed higher values than the OK. In addition, the comparison of the four semi-variagram models (Circular, Spherical, Exponential and Gaussian) for the OK indicated that the circular model had the lowest MAE (32.34) and the highest accuracy (0.976), while the MAE of the exponential model was the highest (33.24). In conclusion, comparing the validation between the training data and test results of the different spatial interpolation methods, the circular model of the OK method was the best one for obtaining accurate spatial interpolation of annual average precipitation in the Loess Plateau region.

  12. Role of the check dam in land development on the Loess Plateau, China

    Science.gov (United States)

    Xu, Xiang-Zhou; Zhang, Luo-Hao; Zhu, Tongxin; Dang, Tian-Min; Zhang, Hong-Wu; Xu, Shi-Guo

    2017-04-01

    Check dam is one of the most effective measures to reduce flow connectivity, which can retain soil and water, and increase land productivity. More than 100,000 check dams have been built on the Loess Plateau since 1950s. However, quantifying the effect of check dams on water resources and water environments remains a challenge. In this study, an in-depth field investigation together with a credible statistical analysis was carried out in two representative catchments on the Loess Plateau, Nanxiaohegou Catchment and Jiuyuangou Catchment, to assess the effectiveness of check dams in soil, water and nutrients conservation. The results show: (1) Check dam plays an important role in conserving water, soil, and nutrients on the Loess Plateau. About half of the total transported water and more than 80 % of the total transported soil and nutrients, had been locally retained in the selected catchments. Hence check dams had a significant benefit to improve soil fertility in the small watersheds, and reducing water pollution downstream of dams. (2) Compared to terrace farmlands, forest lands and grasslands, check-dam lands were much more important in conserving water, soil and nutrients in the catchments. Nearly 50% of the reduced water and more than 70% of the stored soil and nutrients in the study catchments were solely retained by the check dams, whereas the area of the dam lands was less than 7% of the total conservation land area. (3) Check dams are still effective in large storms even if dams were damaged by floods. It is often assumed that check dams could only retain sediment in small flood events whereas most of the stored soil may be washed out as the dams may be destroyed in a disastrous flood. Furthermore, if a major check dam, namely the key project dam, was built in the gully outlet, the flood could be controlled, and thereupon the dam-break can be also avoided. We suggest that a compensation and incentive policy be implemented on dam building to realize the

  13. Effect of Different Vegetation Types on the Rhizosphere Soil Microbial Community Structure in the Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chao; LIU Guo-bin; XUE Sha; and XIAO Lie

    2013-01-01

    The Loess Plateau in China is one of the most eroded areas in the world. Accordingly, vegetation restoration has been implemented in this area over the past two decades to remedy the soil degradation problem. Understanding the microbial community structure is essential for the sustainability of ecosystems and for the reclamation of degraded arable land. This study aimed to determine the effect of different vegetation types on microbial processes and community structure in rhizosphere soils in the Loess Plateau. The six vegetation types were as follows:two natural grassland (Artemisia capillaries and Heteropappus altaicus), two artificial grassland (Astragalus adsurgens and Panicum virgatum), and two artificial shrubland (Caragana korshinskii and Hippophae rhamnoides) species. The microbial community structure and functional diversity were examined by analyzing the phospholipid fatty acids (PLFAs) and community-level physiological profiles. The results showed that rhizosphere soil sampled from the H. altaicus and A. capillaries plots had the highest values of microbial biomass C, average well color development of carbon resources, Gram-negative (G-) bacterial PLFA, bacterial PLFA, total PLFA, Shannon richness, and Shannon evenness, as well as the lowest metabolic quotient. Soil sampled from the H. rhamnoides plots had the highest metabolic quotient and Gram-positive (G+) bacterial PLFA, and soil sampled from the A. adsurgens and A. capillaries plots had the highest fungal PLFA and fungal:bacterial PLFA ratio. Correlation analysis indicated a signiifcant positive relationship among the microbial biomass C, G- bacterial PLFA, bacterial PLFA, and total PLFA. In conclusion, plant species under arid climatic conditions signiifcantly affected the microbial community structure in rhizosphere soil. Among the studied plants, natural grassland species generated the most favorable microbial conditions.

  14. Spatial distribution and temporal trends of mercury and arsenic in remote timberline coniferous forests, eastern of the Tibet Plateau, China.

    Science.gov (United States)

    Tang, Ronggui; Wang, Haiming; Luo, Ji; Sun, Shouqin; Gong, Yiwen; She, Jia; Chen, Youchao; Dandan, Yang; Zhou, Jun

    2015-08-01

    An intensive investigation was conducted to study the spatial distribution and temporal variety trend of mercury and arsenic in plant tissue and soil profile in the eastern of the Tibet Plateau and to explore the possible sources of these two elements. At present, rare information is available on mercury (Hg) and arsenic (As) of timberline forests in the Tibet Plateau. Here, we present preliminary results on these two elements in leaves, twigs, root, litterfall, and soil. Geostatistical analyst of the ArcGIS 10.0 was used to determine the trait of spatial distribution of these two elements. Total arsenic (TAs) mean concentrations in the leaves, twigs, root, litterfall, and A- and C-layer soil ranged from 0.12 mg kg(-1) (n = 60), 0.35 mg kg(-1) (n = 60), 0.48 mg kg(-1) (n = 42), 1.52 mg kg(-1) (n = 84), 16.51 mg kg(-1) (n = 69), and 26.72 mg kg(-1) (n = 69), respectively. Total Hg (THg) mean concentrations in leaves, twigs, root, litterfall, and A- and C-layer soil were 0.0121 mg kg(-1) (n = 60), 0.0078 mg kg(-1) (n = 60), 0.0171 mg kg(-1) (n = 42), 0.0479 mg kg(-1) (n = 84), 0.0852 mg kg(-1) (n = 75), and 0.0251 mg kg(-1) (n = 75), respectively. In general, litterfall trended to accumulate high concentrations of Hg and As. Mercury in the timberline forest showed an increasing trend, whereas arsenic concentrations showed a decreasing trend in A-layer soil and an increasing trend in C-layer soil due to the easy mobile ability of As. Southwest and southeast monsoon could be the influencing factors, and Hg emission from India and China was the possible source of this study area through using a HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model. It is believed that these observations may offer scientists and policymakers additional understanding of Hg and As concentrations in the remote timberline area, eastern of the Tibet Plateau.

  15. An abrupt rainfall decrease over the Asian inland plateau region around 1999 and the possible underlying mechanism

    Science.gov (United States)

    Piao, Jinling; Chen, Wen; Wei, Ke; Liu, Yong; Graf, Hans-F.; Ahn, Joong-Bae; Pogoreltsev, Alexander

    2017-04-01

    A decadal change in summer rainfall in the Asian inland plateau (AIP) region is identified around 1999. This decadal change is characterized by an abrupt decrease in summer rainfall of about 15.7% of the climatological average amount, leading to prolonged drought in the Asian inland plateau region. Both the surface air temperature and potential evapotranspiration in the AIP show a significant increase, while the soil moisture exhibits a decrease, after the late 1990s. Furthermore, the normalized difference vegetation index shows an apparent decreasing trend during 1999-2007. Three different drought indices—the standardized precipitation index, the standardized precipitation evapotranspiration index, and the self-calibrating Palmer drought severity index—present pronounced climate anomalies during 1999-2007, indicating dramatic drought exacerbation in the region after the late 1990s. This decadal change in the summer rainfall may be attributable to a wave-like teleconnection pattern from Western Europe to Asia. A set of model sensitivity experiments suggests that the summer warming sea surface temperature in the North Atlantic could induce this teleconnection pattern over Eurasia, resulting in recent drought in the AIP region.

  16. Cenozoic sediment flux in the Qaidam Basin, northern Tibetan Plateau, and implications with regional tectonics and climate

    Science.gov (United States)

    Bao, Jing; Wang, Yadong; Song, Chunhui; Feng, Ying; Hu, Chunhua; Zhong, Sirui; Yang, Jiwei

    2017-08-01

    As the largest Mesozoic-Cenozoic terrestrial intermountain basin in the northern Tibetan Plateau, the Qaidam Basin is an ideal basin to examine the influences of regional tectonics and climate on sediment flux. Research conducted over the last two decades has provided abundant information about paleoclimatology and tectonic histories. In this study, we used the restoration of seven balanced cross-sections and compiled thickness data of ten outcrop sections and four boreholes to reconstruct the basin boundaries, develop isopach maps, and calculate the sediment flux in the Qaidam Basin. Our results show that the sediment flux in the Qaidam Basin increased gradually between 53.5 and 35.5 Ma, decreased to its lowest value from 35.5 to 22 Ma, increased between 22 and 2.5 Ma, and then increased dramatically after 2.5 Ma. By comparing the changes in the sediment flux with our reconstructed shortening rate in the Qaidam Basin, and the records of regional tectonic events and regional and global climate changes, we suggest that the gradual increase in the sediment flux from 53.5 to 40.5 Ma was controlled by both the tectonic uplift of the Tibetan Plateau and the relatively warm and humid climate, and that the high sediment flux from 40.5 to 35.5 Ma was mainly controlled by tectonics. The low sediment flux from 35.5 to 22 Ma was a response to the relatively cold and arid climate in a stable tectonic setting. The relatively high sediment flux between 22 and 15.3 Ma was related to tectonic activity and the warm and humid climate. The intense tectonic uplift of the northern Tibetan Plateau and the frequent climate oscillations after 15.3 Ma, particularly the glacial-interglacial cycles after 2.5 Ma, caused the high sediment flux after 15.3 Ma and the dramatic increase after 2.5 Ma, respectively.

  17. Effects of Absorbing Aerosols on Accelerated Melting of Snowpack in the Hindu-Kush-Himalayas-Tibetan Plateau Region

    Science.gov (United States)

    Lau, William K.; Kyu-Myong, Kim; Yasunari, Teppei; Gautam, Ritesh; Hsu, Christina

    2011-01-01

    The impacts of absorbing aerosol on melting of snowpack in the Hindu-Kush-Himalayas-Tibetan Plateau (HKHT) region are studied using in-situ, satellite observations, and GEOS-5 GCM. Based on atmospheric black carbon measurements from the Pyramid observation ( 5 km elevation) in Mt. Everest, we estimate that deposition of black carbon on snow surface will give rise to a reduction in snow surface albedo of 2- 5 %, and an increased annual runoff of 12-34% for a typical Tibetan glacier. Examination of satellite reflectivity and re-analysis data reveals signals of possible impacts of dust and black carbon in darkening the snow surface, and accelerating spring melting of snowpack in the HKHT, following a build-up of absorbing aerosols in the Indo-Gangetic Plain. Results from GCM experiments show that 8-10% increase in the rate of melting of snowpack over the western Himalayas and Tibetan Plateau can be attributed to the elevated-heat-pump (EHP) feedback effect, initiated from the absorption of solar radiation by dust and black carbon accumulated to great height ( 5 km) over the Indo-Gangetic Plain and Himalayas foothills in the pre-monsoon season (April-May). The accelerated melting of the snowpack is enabled by an EHP-induced atmosphere-land-snowpack positive feedback involving a) orographic forcing of the monsoon flow by the complex terrain, and thermal forcing of the HKHT region, leading to increased moisture, cloudiness and rainfall over the Himalayas foothills and northern India, b) warming of the upper troposphere over the Tibetan Plateau, and c) an snow albedo-temperature feedback initiated by a transfer of latent and sensible heat from a warmer atmosphere over the HKHT to the underlying snow surface. Results from ongoing modeling work to assess the relative roles of EHP vs. snow-darkening effects on accelerated melting of snowpack in HKHT region will also be discussed.

  18. 植被覆盖度和综合治理对纸坊沟流域土壤氮素流失的影响%Effects of Vegetation Coverage and Management Practice on Soil Nitrogen Loss by Erosion in a Hilly Region of the Loess Plateau in China

    Institute of Scientific and Technical Information of China (English)

    张兴昌; 邵明安

    2003-01-01

    同小流域土壤侵蚀一样,小流域土壤氮素随洪流流失也受到植被覆盖度的影响,通常经过调整小流域内土地利用结构以达到控制水土流失.该研究以8.27 km2纸坊沟流域和1:400比例流域模型为研究对象,研究植被覆盖度和综合治理对纸坊沟流域土壤氮素流失的影响.结果表明:在模拟降雨下,当流域植被覆盖度分别为60%、40%、20%和0时,流域模型铵态氮流失量分别为87.08、44.31、25.16和13.71 kg/km2,硝态氮为85.50、74.05、63.95和56.23 kg/km2,全氮为0.81、1.18、1.98和7.51 t/km2;在自然降雨下,1998年与1992年相比,全流域年土壤侵蚀量为1 086 t/km2和1 119 t/km2,氮素流失量为8 758.5和7 562.2 kg,减少了15.8%,其中农地减少了52.0%.流域对降水中的矿质氮具有过滤作用,硝态氮的过滤作用明显高于铵态氮.洪流泥沙中<20 μm微团聚体富集造成了泥沙有机质和全氮的富集.植被覆盖虽能有效地减少流域土壤侵蚀和全氮的流失,却能增加土壤矿质氮的流失.坡地退耕还林草可显著减少流域土壤氮素流失.%Soil erosion and nutrient loss due to erosion are world-wide problems. Similar to soil loss byerosion, soil nitrogen (N) loss by erosion in small catchments is affected by vegetation coverage. Thepractice of comprehensive management for catchments mainly by adjusting cropland, grassland and wood-land areas was widely adopted to reduce soil and water loss in catchments of the Chinese Loess Plateau.Three experiments under natural and artificial rainfall conditions on N loss by erosion for a model catch-ment and for an actual catchment in Zhifanggou of Ansai County in China was performed to determine therelationships between comprehensive management and N loss by runoff in small catchments. The resultsfor vegetation coverage of 60%, 40%, 20% and 0 show that runoff loss of ammonium, nitrate, and total Nwere 87.08, 44.31, 25.16, 13.71 kg/km2; 85.50 74.06, 63.95, 56.23 kg

  19. [SGP polymorphism in cultivated naked barley from Qinghai-Tibet plateau in China and the relationship between SGPs and starch content].

    Science.gov (United States)

    Pan, Zhi-Fen; Zhou, Yi-Xing; Zhao, Tao; Deng, Guang-Bing; Zhai, Xu-Guang; Wu, Fang; Yu, Mao-Qun

    2007-05-01

    Starch granule proteins (SGPs) are minor components bound with starch granule, which mutation may be related to starch properties. This study investigated the variation of SGPs in cultivated naked barley from Qinghai-Tibet Plateau in China for the first time, and the relationship between SGPs and starch content was preliminarily done. Ten major SGPs and 16 types of patterns were present in 66 cultivated naked varieties, indicating SGPs in cultivated naked barley from Qinghai-Tibet Plateau in China are polymorphic. SGPs in Tibet and Sichuan naked barley were greatly different and SGPs were specific to origin of site. Significance test analysis demonstrates SGPs described in this study except for SGP1 may be related with the variation of starch content in different naked barley.

  20. Effects of straw and biochar amendments on aggregate stability, soil organic carbon, and enzyme activities in the Loess Plateau, China.

    Science.gov (United States)

    Zhang, Man; Cheng, Gong; Feng, Hao; Sun, Benhua; Zhao, Ying; Chen, Haixin; Chen, Jing; Dyck, Miles; Wang, Xudong; Zhang, Jianguo; Zhang, Afeng

    2017-02-23

    Soil from the Loess Plateau of China is typically low in organic carbon and generally has poor aggregate stability. Application of organic amendments to these soils could help to increase and sustain soil organic matter levels and thus to enhance soil aggregate stability. A field experiment was carried out to evaluate the effect of the application of wheat straw and wheat straw-derived biochar (pyrolyzed at 350-550 °C) amendments on soil aggregate stability, soil organic carbon (SOC), and enzyme activities in a representative Chinese Loess soil during summer maize and winter wheat growing season from 2013 to 2015. Five treatments were set up as follows: no fertilization (CK), application of inorganic fertilizer (N), wheat straw applied at 8 t ha(-1) with inorganic fertilizer (S8), and wheat straw-derived biochar applied at 8 t ha(-1) (B8) and 16 t ha(-1) (B16) with inorganic fertilizer, respectively. Compared to the N treatment, straw and straw-derived biochar amendments significantly increased SOC (by 33.7-79.6%), microbial biomass carbon (by 18.9-46.5%), and microbial biomass nitrogen (by 8.3-38.2%), while total nitrogen (TN) only increased significantly in the B16 plot (by 24.1%). The 8 t ha(-1) straw and biochar applications had no significant effects on soil aggregation, but a significant increase in soil macro-aggregates (>2 mm) (by 105.8%) was observed in the B16 treatment. The concentrations of aggregate-associated SOC increased by 40.4-105.8% in macro-aggregates (>2 mm) under straw and biochar amendments relative to the N treatment. No significant differences in invertase and alkaline phosphatase activity were detected among different treatments. However, urease activity was greater in the biochar treatment than the straw treatment, indicating that biochar amendment improved the transformation of nitrogen in the soil. The carbon pool index and carbon management index were increased with straw and biochar amendments, especially in the B16

  1. Shiga toxin-producing Escherichia coli in yaks (Bos grunniens from the Qinghai-Tibetan Plateau, China.

    Directory of Open Access Journals (Sweden)

    Xiangning Bai

    Full Text Available Shiga toxin (Stx-producing Escherichia coli (STEC are recognized as important human pathogens of public health concern. Many animals are the sources of STEC. In this study we determined the occurrence and characteristics of the STEC in yaks (Bos grunniens from the Qinghai-Tibetan plateau, China. A total of 728 yak fecal samples was collected from June to August, 2012 and was screened for the presence of the stx 1 and stx 2 genes by TaqMan real-time PCR after the sample was enriched in modified Tryptone Soya Broth. Of the 138 (18.96% stx 1 and/or stx 2-positive samples, 85 (61.59% were confirmed to have at least 1 STEC isolate present by culture isolation, from which 128 STEC isolates were recovered. All STEC isolates were serotyped, genotyped by pulsed-field gel electrophoresis (PFGE and characterized for the presence of 16 known virulence factors. Fifteen different O serogroups and 36 different O:H serotypes were identified in the 128 STEC isolates with 21 and 4 untypable for the O and H antigens respectively. One stx 1 subtype (stx 1a and 5 stx 2 subtypes (stx 2a, stx 2b, stx 2c, stx 2d and stx 2g were present in these STEC isolates. Apart from lpfA O157/OI-141, lpfA O157/OI-154, lpfA O113, katP and toxB which were all absent, other virulence factors screened (eaeA, iha, efa1, saa, paa, cnf1, cnf2, astA, subA, exhA and espP were variably present in the 128 STEC isolates. PFGE were successful for all except 5 isolates and separated them into 67 different PFGE patterns. For the 18 serotypes with 2 or more isolates, isolates of the same serotypes had the same or closely related PFGE patterns, demonstrating clonality of these serotypes. This study was the first report on occurrence and characteristics of STEC isolated from yaks (Bos grunniens from the Qinghai-Tibetan plateau, China, and extended the genetic diversity and reservoir host range of STEC.

  2. Evaluation of the AquaCrop model for simulating yield response of winter wheat to water on the southern Loess Plateau of China.

    Science.gov (United States)

    Zhang, Wanhong; Liu, Wenzhao; Xue, Qingwu; Chen, Jie; Han, Xiaoyang

    2013-01-01

    The objective of this study was to evaluate the performance of the FAO-AquaCrop model in winter wheat in the southern Loess Plateau of China. Multi-year field experimental data from 2004 and 2011 were used to calibrate and validate the model for simulating biomass, canopy cover (CC), soil water content, and grain yield under rainfed conditions. The model performance was evaluated using root mean square error (RMSE) and Willmott index of agreement (d) as criteria. The RMSE ranged from 0.16 to 0.38 t/ha for simulating aboveground biomass, 1.87 to 4.15% for CC, 0.50 to 1.44 t/ha for grain yield, and 5.70 to 22.56 mm for soil water content. The d ranged from 0.22 to 0.89, 0.25 to 0.43, 0.36 to 0.62 and 0.95 to 0.98 for aboveground biomass, CC, soil water content and grain yield, respectively. Generally, the model performed better for simulating CC and yield than biomass and soil water content. The results further indicated that AquaCrop is capable of simulating winter wheat yield under rainfed conditions. Further improvement may be needed to capture the variation of different management practices such as fertility and irrigation levels in this region.

  3. Effects of ecological restoration projects on changes in land cover: A case study on the Loess Plateau in China

    Science.gov (United States)

    Zhao, Jun; Yang, Yanzheng; Zhao, Qingxia; Zhao, Zhong

    2017-03-01

    Changes in land cover have become key components of global environmental change and represent the impact of human activity. To better understand the fundamental processes of land transition characteristics before and after the implementation of ecological programmes, we determined the dominant systematic changes in land cover in Yongshou, a hilly-gully region on the Loess Plateau. This was achieved by performing an in-depth analysis of a cross-tabulation matrix and a modified spatial dynamic degree model. Our results indicated that (1) forest land and cultivated land were the most important land cover types in Yongshou and their persistence would greatly affect the landscape pattern of the entire region; (2) the most significant changing signals in the study area during the periods 1992–2000 and 2000–2013 were from immature forest land to forest land, cultivated land to orchards and orchards to construction land; and (3) the region that experienced the most changes during 1992–2000 was the densely populated county seat of Yongshou; however, from 2000–2013, the region of most changes was Changning, a town located in the northcentral region of Yongshou. These findings reveal the main characteristics of the land cover changes in this region and provide insight into the processes underlying these changes.

  4. Effects of ecological restoration projects on changes in land cover: A case study on the Loess Plateau in China

    Science.gov (United States)

    Zhao, Jun; Yang, Yanzheng; Zhao, Qingxia; Zhao, Zhong

    2017-01-01

    Changes in land cover have become key components of global environmental change and represent the impact of human activity. To better understand the fundamental processes of land transition characteristics before and after the implementation of ecological programmes, we determined the dominant systematic changes in land cover in Yongshou, a hilly-gully region on the Loess Plateau. This was achieved by performing an in-depth analysis of a cross-tabulation matrix and a modified spatial dynamic degree model. Our results indicated that (1) forest land and cultivated land were the most important land cover types in Yongshou and their persistence would greatly affect the landscape pattern of the entire region; (2) the most significant changing signals in the study area during the periods 1992–2000 and 2000–2013 were from immature forest land to forest land, cultivated land to orchards and orchards to construction land; and (3) the region that experienced the most changes during 1992–2000 was the densely populated county seat of Yongshou; however, from 2000–2013, the region of most changes was Changning, a town located in the northcentral region of Yongshou. These findings reveal the main characteristics of the land cover changes in this region and provide insight into the processes underlying these changes. PMID:28322250

  5. Effects of ecological restoration projects on changes in land cover: A case study on the Loess Plateau in China.

    Science.gov (United States)

    Zhao, Jun; Yang, Yanzheng; Zhao, Qingxia; Zhao, Zhong

    2017-03-21

    Changes in land cover have become key components of global environmental change and represent the impact of human activity. To better understand the fundamental processes of land transition characteristics before and after the implementation of ecological programmes, we determined the dominant systematic changes in land cover in Yongshou, a hilly-gully region on the Loess Plateau. This was achieved by performing an in-depth analysis of a cross-tabulation matrix and a modified spatial dynamic degree model. Our results indicated that (1) forest land and cultivated land were the most important land cover types in Yongshou and their persistence would greatly affect the landscape pattern of the entire region; (2) the most significant changing signals in the study area during the periods 1992-2000 and 2000-2013 were from immature forest land to forest land, cultivated land to orchards and orchards to construction land; and (3) the region that experienced the most changes during 1992-2000 was the densely populated county seat of Yongshou; however, from 2000-2013, the region of most changes was Changning, a town located in the northcentral region of Yongshou. These findings reveal the main characteristics of the land cover changes in this region and provide insight into the processes underlying these changes.

  6. Phylogeography of an alpine plant (Bupleurum smithii, Apiaceae) endemic to the Qinghai-Tibetan Plateau and adjacent regions inferred from chloroplast DNA sequence variation

    Institute of Scientific and Technical Information of China (English)

    Cai ZHAO; Xiang-Guang MA; Qian-Long LIANG; Chang-Bao WANG; Xing-Jin HE

    2013-01-01

    To obtain a better understanding of how Quaternary climatic oscillations influenced range distributions and intraspecific split of alpine plants on the Qinghai-Tibetan Plateau (QTP) and in adjacent regions,we investigated the extant phylogeographical structure of Bupleurum smithii in this area based on 22 populations and 103 individuals spanning the entire distribution region of this species using chloroplast DNA sequences.Two major haplotype lineages were identified,and at least two corresponding glacial refugia maintaining in the northeastern and eastern edge of the QTP during the Last Glacial Maximum were revealed.Secondary contact between populations and efficient gene flow were also found between two major haplotype lineages.In addition,based on the geographic distribution of haplotypes,we found that populations on the platform derived from individuals that recolonized this area from refugia situated at the northeastem and eastern edges of the QTP,and that B.smithii recolonized from southern to northern China during inter-and post-glacial periods.

  7. Regional Lithological Mapping Using ASTER-TIR Data: Case Study for the Tibetan Plateau and the Surrounding Area

    Directory of Open Access Journals (Sweden)

    Yoshiki Ninomiya

    2016-09-01

    Full Text Available The mineralogical indices the Quartz Index (QI, Carbonate Index (CI and Mafic Index (MI for ASTER multispectral thermal infrared (TIR data were applied to various geological materials for regional lithological mapping on the Tibetan Plateau. Many lithological and structural features are not currently well understood in the central Tibetan Plateau, including the distribution of mafic-ultramafic rocks related to the suture zones, the quartzose and carbonate sedimentary rocks accreted to the Eurasian continent, and sulfate layers related to the Tethys and neo-Tethys geological setting. These rock types can now be mapped with the interpretation of the processed ASTER TIR images described in this paper. A methodology is described for the processing of ASTER TIR data applied to a very wide region of the Tibetan Plateau. The geometrical and radiometric performance of the processed images is discussed, and the advantages of using ortho-rectified data are shown. The challenges of using ASTER data with a small footprint in addition to selecting an appropriate subset of scenes are also examined. ASTER scenes possess a narrow swath width when compared to LANDSAT data (60 km vs. 185 km, respectively. Furthermore, the ASTER data archive is vast, consisting of approximately three million images. These details can present an added level of complexity during an image processing workflow. Finally, geological interpretations made on the maps of the indices are compared with prior geological field studies. The results from the investigations suggest that the indices perform well in the classification of quartzose rocks based on the carbonate and mafic mineral content, in addition to the granitic rocks based on the feldspar content.

  8. Structural Variation of an Atmospheric Heat Source over the Qinghai-Xizang Plateau and Its Influence on Precipitation in Northwest China

    Institute of Scientific and Technical Information of China (English)

    WEI Na; GONG Yuanfa; HE Jinhai

    2009-01-01

    NCEP/NCAR reanalysis data and a 47-year precipitation dataset are utilized to analyze the relationship between an atmospheric heat source (hereafter called ) over the Qinghai-Xizang Plateau (QXP) and its surrounding area and precipitation in northwest China.Our main conclusions are as follows:(1) The horizontal distribution of and its changing trend are dramatic over QXP in the summer.There are three strong centers of over the south side of QXP with obvious differences in the amount of yearly precipitation and the number of heat sinks predominate in the arid and semi-arid regions of northwest China (NWC),beside the northern QXP with an obvious higher intensity in years with less precipitation.(2) In the summer,the variation of the heat source's vertical structure is obviously different between greater and lesser precipitation years in eastern northwest China (ENWC).The narrow heat sink belt forms between the northeast QXP and the southwestern part of Lake Baikal.In July and August of greater precipitation years,the heating center of the eastern QXP stays nearly over 35°N,and at 400 hPa of the eastern QXP,the strong upward motion of the heating center constructs a closed secondary vertical circulation cell over the northeast QXP (40°-46°N),which is propitious to add precipitation over the ENWC.Otherwise,the heating center shifts to the south of 30°N and disappears in July and August of lesser precipitation years,an opposite secondary circulation cell forms over the northeast QXP,which is a disadvantage for precipitation.Meanwhile,the secondary circulation cell in years with more or less precipitation over the ENWC is also related to the heat source over the Lake Baikal. (3) The vertical structure of the heat source over the western QXP has obvious differences between greater and lesser precipitation years in western northwest China in June and July.The strong/weak heat source over the western QXP produces relatively strong/weak ascending motion and

  9. Groundwater status and trends for the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Burns, Erick R.; Snyder, Daniel T.; Haynes, Jonathan V.; Waibel, Michael S.

    2012-01-01

    Well information and groundwater-level measurements for the Columbia Plateau Regional Aquifer System in Washington, Oregon, and Idaho, were compiled from data provided by the U.S. Geological Survey and seven other organizations. From the full set of about 60,000 wells and 450,000 water-level measurements a subset of 761 wells within the aquifers of the Columbia River Basalt Group (CRBG) then was used to develop a simple linear groundwater-level trend map for 1968–2009. The mean of the trends was a decline of 1.9 feet per year (ft/yr), with 72 percent of the water levels in wells declining. Rates of declines greater than 1.0 ft/yr were measured in 50 percent of wells, declines greater than 2.0 ft/yr in 38 percent of wells, declines greater than 4.0 ft/yr in 29 percent of wells, and declines greater than 8.0 ft/yr in 4 percent of wells. Water-level data were used to identify groups of wells with similar hydraulic heads and temporal trends to delineate areas of overall similar groundwater conditions. Discontinuities in hydraulic head between well groups were used to help infer the presence of barriers to groundwater flow such as changes in lithology or the occurrence of folds and faults. In areas without flow barriers, dissimilarities in response of well groups over time resulted from the formation of groundwater mounds caused by recharge from irrigation or regions of decline caused by pumping. The areas of focus for this analysis included the Umatilla area, Oregon, and the Palouse Slope/eastern Yakima Fold Belt in the Columbia Basin Ground Water Management Area (GWMA) consisting of Adams, Franklin, Grant, and Lincoln Counties, Washington. In the Umatilla area, water levels from 286 wells were used to identify multiple areas of high hydraulic gradient that indicate vertical and horizontal barriers to groundwater flow. These barriers divide the groundwater-flow system into several compartments with varying degrees of interconnection. Horizontal flow barriers commonly

  10. Airborne pollen assemblages and weather regime in the central-eastern Loess Plateau, China

    Science.gov (United States)

    Li, Yuecong; Ge, Yawen; Xu, Qinghai; Bunting, Jane M.; Lv, Suqing; Wang, Junting; Li, Zetao

    2015-04-01

    This paper presents the results of pollen trapping studies designed to quantify the pollen assemblages carried in the winds of the Loess Plateau in Luochuan and Hunyuan. The one-year-collection samples analysis results show that pollen assemblages can be more sensitive to the change of climate than the vegetation composition, because of the change of pollen production. The analysis results of pollen traps in different weather regimes indicate that the pollen influx coming from dust weather contribute more to the total pollen influx than that coming from non-dust weather. The wind speed is the most important influenced factor to pollen assemblages, then the mean temperature and the mean relative humidity, the wind direction also contributes some. Strong wind coming from dust direction can make the percent and influx of Artemisia and Chenopodiaceae increase obviously with averagely higher than over 2.7 times in dust weather than in non-dust samples. The influences of wind speed and wind direction are not serious to some arboreal pollen such as Rosaceae, Quercus, Betula, Pinus and Ostryopsis, which are mainly influenced by temperature or the relative humidity such as Salix, Hippophae, Carpinus, Brassicaceae, Cupressaceae, Fabaceae.

  11. [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.

  12. Towards sustainable integrated watershed ecosystem management: a case study in Dingxi on the loess plateau, China.

    Science.gov (United States)

    Chen, Liding; Yang, Lei; Wei, Wei; Wang, Ziting; Mo, Baoru; Cai, Guojun

    2013-01-01

    The Chinese government initiated a massive conservation program called "Grain-for-Green" in 1999 to reduce soil erosion and improve ecosystem function. Implementing practical sustainable development in the loess plateau still remains problematic, particularly in its eco-fragile areas. Here we discussed an approach for sustainable development at the watershed scale by integrating land use suitability, ecosystem services and public participation in the loess hilly area. We linked land use scenario analysis and economic modeling to compare the outcomes of three scenarios, CLU (Current Land Use), GOLU (Grain-production Oriented Land Use) and PSLU (Potential Sustainable Land Use). The results indicated that compared to PSLU, GOLU may provide a higher economic productivity in the short-term, but not in the long-term. CLU ranked lowest in terms of economic benefits and did not meet the daily needs of the local farmers. To reconcile the land use adjustments with farmers' basic needs, a labor-saving land use strategy is necessary. Since the PSLU scenario assumes that slope cropland should be converted to pastures or orchards, more time may be available for off-farm work and for more public participation in integrated ecosystem management. Financial support to the local farmers for environmental conservation should be modulated in function of their positive contribution to ecosystem management.

  13. Vertical distribution characteristics of soil organic carbon content in Caohai wetland ecosystem of Guizhou plateau, China

    Institute of Scientific and Technical Information of China (English)

    Yunjie Wu; Fengyou Wang; Sixi Zhu

    2016-01-01

    We selected four kinds of land use types from Caohai wetlands of Guizhou plateau (a total number of 32 soil profiles) to study the distribution characteristics of organic carbon content in soil. With different ways of land use, the organic carbon content of soil profiles and organic carbon density show the tendency of decreasing firstly and then increasing from top to bottom. With the increase of depth, the vertical difference becomes smaller first and then starts increasing. Land reclamation reduces the soil organic carbon content and density, changing its distribu-tion structure in topsoil. The average content of organic carbon in Caohai wetlands are as follows: lake bed silt [ marsh wetland [ farmland [ woodland, the average organic carbon content of lake bed silt, marsh wetland, farmland and woodland are 16.40, 2.94, 1.81 and 1.08%, respectively. Land reclamation reduces the organic carbon content of soil, therefore the conversion of cultivated lands to wetlands and the increase of forest coverage will help to fix the organic carbon in soil and increase its reserves.

  14. Towards Sustainable Integrated Watershed Ecosystem Management: A Case Study in Dingxi on the Loess Plateau, China

    Science.gov (United States)

    Chen, Liding; Yang, Lei; Wei, Wei; Wang, Ziting; Mo, Baoru; Cai, Guojun

    2013-01-01

    The Chinese government initiated a massive conservation program called "Grain-for-Green" in 1999 to reduce soil erosion and improve ecosystem function. Implementing practical sustainable development in the loess plateau still remains problematic, particularly in its eco-fragile areas. Here we discussed an approach for sustainable development at the watershed scale by integrating land use suitability, ecosystem services and public participation in the loess hilly area. We linked land use scenario analysis and economic modeling to compare the outcomes of three scenarios, CLU (Current Land Use), GOLU (Grain-production Oriented Land Use) and PSLU (Potential Sustainable Land Use). The results indicated that compared to PSLU, GOLU may provide a higher economic productivity in the short-term, but not in the long-term. CLU ranked lowest in terms of economic benefits and did not meet the daily needs of the local farmers. To reconcile the land use adjustments with farmers' basic needs, a labor-saving land use strategy is necessary. Since the PSLU scenario assumes that slope cropland should be converted to pastures or orchards, more time may be available for off-farm work and for more public participation in integrated ecosystem management. Financial support to the local farmers for environmental conservation should be modulated in function of their positive contribution to ecosystem management.

  15. Spatial analysis of Budovar stream catchment (Srem Loess Plateau, Serbia) in a tectonically active region

    Science.gov (United States)

    Jovanovic, Mladjen; Rvovic, Ivan; Sorak, Rada; Petrovic, Milos

    2016-04-01

    Budovar is the far longest stream on Srem Loess Plateau, with a length of a 52 km, and catchment area of 245 km2. Budovar stream drains a quite complex landscape in terms of generally flat loess plateau, with elevations decreasing gradually southeastward - from 213 m at slopes of Fru\\vska Gora Mountain to 70,9 m at the confluence with Danube river. The youngest (Pleistocene/Holocene) sedimentary formations in the catchment vary from slope loess on Fru\\vska Gora Mtn. in upper part, through typical plateau loess in middle part, and the finest bog-sediments in tectonic depressions in lower part. These deposits lie over the bog-lake-terrestrial sediments with thickness over 100 m. According the geodetic measurements, uplift of Fru\\vska Gora Mtn., which has been the strongest during the Middle Pleistocene, is still present, with rates of up to 1 mm/y in contrast of general uplift of the area, subsidence is recorded in two distinct parts of the catchment. Spatial analysis is done using a DEM, generated in ArcGIS 10.0 from the elevation points, 10 m contours and stream coverage available in 1:25.000 topographical maps. Both longitudinal and cross-section profiles of the valley reflect the influence of tectonic distortions and climatic fluctuations. Valleys in Budovar catchment have composite character - the valleys cross-sections vary from deep incised V-shape, reversed trapezoid shape and completely flat valleys in tectonic depressions. Moreover, there is almost no correlation between the shape of cross-sectional profiles and the direction of curvature of the main valley's long axis (left/right or straight), suggesting that the tectonic activity has the key role in shaping. The width of valleys in Budovar catchment area is in sharp contrast with present stream discharge, which suggests strong climate fluctuations since Upper Pleistocene. The longitudinal profiles also shows signs of kickpoints and some short reaches with increasing elevation in the flow direction. Key

  16. Reconstruction of biological drought conditions during the past 2847 years in an alpine environment of the northeastern Tibetan Plateau, China, and possible linkages to solar forcing

    Science.gov (United States)

    Yin, Zhi-Yong; Zhu, Haifeng; Huang, Lei; Shao, Xuemei

    2016-08-01

    In this study we reconstructed the moisture condition of the eastern Qaidam Basin of the northeastern Tibetan Plateau based on a 3585-year tree ring chronology. The growth environment of Qilian juniper (Sabina przewalskii Kom.) on the mountains in the eastern Qaidam Basin was first determined by comparing precipitation and temperature estimates from two spatial datasets (PRISM and World Climate). Moisture balance was calculated as the sum of simulated moisture deficit (negative) and surplus using a modified Thornthwaite water balance model, and used as a proxy of biological drought conditions. Using data during 1956-2005, we established the transfer function to reconstruct a 2847-year series of January-June moisture balance (843 BCE-2004 CE). With an adjusted R2 value of 0.654 of the transfer function and strong performance in validation, the reconstructed January-June moisture balance can be considered an excellent indicator of biological drought conditions for the study region. The reconstructed series showed strong correlations with reconstructed PDSI in the monsoon Asian region, representing a region of 10° latitudes by 20° longitudes. Using the reconstructed series, we identified centennial-scale dry periods since 843 BCE: 381-277 BCE, 425-520 CE, 1108-1212 CE, 1428-1516 CE, and 1634-1743 CE. Additionally it had statistically significant negative correlations with a monsoon intensity proxy based on oxygen stable isotope from southwestern China (Dongge Cave). Further analyses identified significant relationships with solar activity, especially during the last 700 years. We confirmed the ~ 200-year cyclic pattern in the reconstructed moisture balance series, which matched the known 210-year de Vries solar cycle and peaked during the Little Ice Age. However, the cyclic patterns of the reconstructed moisture balance series and solar activity were decoupled for the period prior to approx. 1300 CE.

  17. Ecosystem Health Assessment at County-Scale Using the Pressure-State-Response Framework on the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    Delin Liu

    2016-12-01

    Full Text Available Assessing ecosystem health is helpful to determine reasonable eco-environmental restoration and resource management strategies. Based on a pressure-state-response (PSR framework, a set of comprehensive indicators including natural, social and economic aspects was proposed and applied for assessing the ecosystem health of Yuanzhou County, Loess Plateau, Ningxia Province, China. The basic data used to calculate the values of the assessment indicators include Landsat TM image and socio-economic data, and remote sensing (RS and the geographic information system (GIS were used to process image data. The results showed that the ecosystem health conditions of most townships in Yuanzhou County were at the moderately healthy level, three townships were at the healthy level, and only two townships were at the unhelathy level; the areas (percentage at the unhealthy, moderately healthy and healthy levels were 443.91 km2 (12.66%, 2438.75 km2 (69.54% and 624.50 km2 (17.81%, respectively. The results could provide useful information for local residents and the government to take measures to improve the health conditions of their township ecosystem.

  18. Diversity and community structure of fungi through a permafrost core profile from the Qinghai-Tibet Plateau of China.

    Science.gov (United States)

    Hu, Weigang; Zhang, Qi; Li, Dingyao; Cheng, Gang; Mu, Jing; Wu, Qingbai; Niu, Fujun; An, Lizhe; Feng, Huyuan

    2014-12-01

    While a vast number of studies have addressed the prokaryotic diversity in permafrost, characterized by subzero temperatures, low water activity, and extremely low rates of nutrient and metabolite transfer, fungal patterns have received surprisingly limited attention. Here, the fungal diversity and community structure were investigated by culture-dependent technique combined with cloning-restriction fragment length polymorphism (RFLP) analysis of sediments in a 10-m-long permafrost core from the Qinghai-Tibet Plateau of China. A total of 62 fungal phylotypes related to 10 distinct classes representing three phyla were recovered from 5031 clones generated in 13 environmental gene libraries. A large proportion of the phylotypes (25/62) that were distantly related to described fungal species appeared to be novel diversity. Ascomycota was the predominant group of fungi, with respect to both clone and phylotype number. Our results suggested there was the existence of cosmopolitan psychrophilic or psychrotolerant fungi in permafrost sediments, the community composition of fungi varied with increasing depth, while these communities largely distributed according to core layers.

  19. Isoenzymes and soluble protein in Arthrospira from alkaline lakes in Erdos Plateau, China and in exotic species

    Science.gov (United States)

    Yang, Qian; Li, Shuyuan; Hu, Ruiping; Liu, Yan; Qiao, Chen

    2006-06-01

    The authors compared isoenzymes of five enzymes and soluble protein in Arthrospira platensis (A3) and A. erdosensis (A4) from alkaline lakes in Erdos Plateau, Nei Monggo (Inner Mongalia), China and exotic species of A. platensis (A1) from Chad and A. maxima (A2) from Mexico by means of polyacrylamide gel electrophoresis. The results showed that the isoenzymes of EST, POD and soluble protein were polymorphic. Monomorphism and polymorphism were found in isoenzymes of AMY, CAT and SOD, and monomorphism was found only in the introduced species. The isoenzymes and soluble protein of the local species are all polymorphic. The number of bands in these species were in the order of A3>A4>A1>A2. A2 is the most primary, A1 from Chad Lake is relatively primary, A3 and A4 are advanced species in evolution. Cluster analysis showed that the relation between the two introduced species are the closest to each other, and so too are the two local ones.

  20. Long-term effects of fertilizer on soil enzymatic activity of wheat field soil in Loess Plateau, China.

    Science.gov (United States)

    Hu, Weigang; Jiao, Zhifang; Wu, Fasi; Liu, Yongjun; Dong, Maoxing; Ma, Xiaojun; Fan, Tinglu; An, Lizhe; Feng, Huyuan

    2014-12-01

    The effects of long-term (29 years) fertilization on local agro-ecosystems in the Loess Plateau of northwest China, containing a single or combinations of inorganic (Nitrogen, N; Phosphate, P) and organic (Mature, M Straw, S) fertilizer, including N, NP, SNP, M, MNP, and a control. The soil enzymes, including dehydrogenase, urease, alkaline phosphatase, invertase and glomalin, were investigated in three physiological stages (Jointing, Dough, and Maturity) of wheat growth at three depths of the soil profile (0-15, 16-30, 31-45 cm). We found that the application of farmyard manure and straw produced the highest values of soil enzymatic activity, especially a balanced applied treatment of MNP. Enzymatic activity was lowest in the control. Values were generally highest at dough, followed by the jointing and maturity stages, and declined with soil profile depth. The activities of the enzymes investigated here are significantly correlated with each other and are correlated with soil nutrients, in particular with soil organic carbon. Our results suggest that a balanced application of fertilizer nutrients and organic manure (especially those containing P) has positive effects on multiple soil chemical parameters, which in turn enhances enzyme activity. We emphasize the role of organic manure in maintaining soil organic matter and promoting biological activity, as its application can result in a substantial increase in agricultural production and can be sustainable for many years.

  1. Isoenzymes and soluble protein in Arthrospira from alkaline lakes in Erdos Plateau, China and in exotic species

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The authors compared isoenzymes of five enzymes and soluble protein in Arthrospira platensis (A3) and A. erdosensis (A4) from alkaline lakes in Erdos Plateau, Nei Monggo (Inner Mongalia),China and exotic species ofA. platensis (A1) from Chad and A. maxima (A2) from Mexico by means of polyacrylamide gel electrophoresis. The results showed that the isoenzymes of EST, POD and soluble protein were polymorphic. Monomorphism and polymorphism were found in isoenzymes of AMY, CAT and SOD, and monomorphism was found only in the introduced species. The isoenzymes and soluble protein of the local species are all polymorphic. The number of bands in these species were in the order of A3>A4>A1 >A2. A2 is the most primary, A1 from Chad Lake is relatively primary, A3 and A4 are advanced species in evolution. Cluster analysis showed that the relation between the two introduced species are the closest to each other, and so too are the two local ones.

  2. Mineral Composition of Loess—Paleosol Samples from the Loess Plateau of China and Its Environmental Significance

    Institute of Scientific and Technical Information of China (English)

    郑洪汉; B.K.G.THENG; 等

    1994-01-01

    34samples of loess-paleosol from the Luochuan and Xifeng sections in the Loess Plateau,northern China were eparated into sand,silt and clay fractions and analyzed for their mineral compositions.The results indicate that there is almost no difference between loess and paleosol in mineral composition.Major mineral species are quartz,mica,feldspar and chlorite,accounting for about 88-92% of the total;other minerals are kandite,smectite,vermiculite and a few heavy minerals.The calcite,magnetite and hematite were not taken into consideration because of their removal in the process of sample preparation.The main difference with respect to the mineral composition of samples collected from different sections and different statigraphic levels lies in the amount and grain size of minerals hosted.Comparisons between the Luochuan section and the Xifeng section,between paleosol and loess and between the upper part and the lower part of some paleosol layers show that the formers contain less feldspar but more mica and vermiculite and are finer in grain size,indicating the co-occurrence of both biochemical weathering process responsible for mineral change and physical weathering process leading to grain-size change during the soil-forming processes.This result favours such an explanation of the soil-forming mechanism that loess deposition and paleosol development occurred synchronously,though the rate of soil formation was greater than that of loess deposition,thus leading to soil development.

  3. Emergence of ancient cities in relation to geopolitical circumstances and climate change during late Holocene in northeastern Tibetan Plateau, China

    Science.gov (United States)

    Dong, Guanghui; Liu, Honggao; Yang, Yishi; Yang, Ying; Zhou, Aifeng; Wang, Zhongxin; Ren, Xiaoyan; Chen, Fahu

    2016-09-01

    The study of the history of human activities in ancient cities has provided valuable evidences for understanding the evolution of human-land relations during the late Holocene. Numerous ancient cities were discovered through archaeological surveys of the east Qinghai Province, located on the northeastern border of the Tibetan Plateau, China; however, the mystery of when or why these cities were built remains unsolved. As recorded in this paper, we sampled reliable dating materials from 47 ancient cities in the area, determined their ages by radiocarbon dating, and compared the dating results with historical documents and high resolution paleoclimate records to explore the influencing factors for the development of these ancient cities. The 54 radiocarbon dates indicated that most of these cities were built or repaired during the Han Dynasty (202 BC‒AD 220), Tang Dynasty (AD 618‒AD 907), the Five Dynasties and Ten Kingdoms period (AD 907‒AD 960), the Song dynasty (AD 960‒AD 1279), and the Ming Dynasty (AD 1368‒AD 1644). The radiocarbon dates correspond well with historical records of the area. Our work suggests the ancient cities in east Qinghai Province were likely built primarily for military defense, and may have also have been affected by climate change.

  4. Vegetation changes in recent large-scale ecological restoration projects and subsequent impact on water resources in China's Loess Plateau.

    Science.gov (United States)

    Li, Shuai; Liang, Wei; Fu, Bojie; Lü, Yihe; Fu, Shuyi; Wang, Shuai; Su, Huimin

    2016-11-01

    Recently, relationship between vegetation activity and temperature variability has received much attention in China. However, vegetation-induced changes in water resources through changing land surface energy balance (e.g. albedo), has not been well documented. This study investigates the underlying causes of vegetation change and subsequent impacts on runoff for the Northern Shaanxi Loess Plateau. Results show that satellite-derived vegetation index has experienced a significantly increasing trend during the past three decades, especially during 2000-2012. Large-scale ecological restorations, i.e., the Natural Forest Conservation project and the Grain for Green project, are found to be the primary driving factors for vegetation increase. The increased vegetation coverage induces decrease in surface albedo and results in an increase in temperature. This positive effect can be counteracted by higher evapotranspiration and the net effect is a decrease in daytime land surface temperature. A higher evapotranspiration rate from restored vegetation is the primary reason for the reduced runoff coefficient. Other factors including less heavy precipitation, increased water consumption from town, industry and agriculture also appear to be the important causes for the reduction of runoff. These two ecological restoration projects produce both positive and negative effects on the overall ecosystem services. Thus, long-term continuous monitoring is needed. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Emergence of ancient cities in relation to geopolitical circumstances and climate change during late Holocene in northeastern Tibetan Plateau, China

    Science.gov (United States)

    Dong, Guanghui; Liu, Honggao; Yang, Yishi; Yang, Ying; Zhou, Aifeng; Wang, Zhongxin; Ren, Xiaoyan; Chen, Fahu

    2016-12-01

    The study of the history of human activities in ancient cities has provided valuable evidences for understanding the evolution of human-land relations during the late Holocene. Numerous ancient cities were discovered through archaeological surveys of the east Qinghai Province, located on the northeastern border of the Tibetan Plateau, China; however, the mystery of when or why these cities were built remains unsolved. As recorded in this paper, we sampled reliable dating materials from 47 ancient cities in the area, determined their ages by radiocarbon dating, and compared the dating results with historical documents and high resolution paleoclimate records to explore the influencing factors for the development of these ancient cities. The 54 radiocarbon dates indicated that most of these cities were built or repaired during the Han Dynasty (202 BC‒AD 220), Tang Dynasty (AD 618‒AD 907), the Five Dynasties and Ten Kingdoms period (AD 907‒AD 960), the Song dynasty (AD 960‒AD 1279), and the Ming Dynasty (AD 1368‒AD 1644). The radiocarbon dates correspond well with historical records of the area. Our work suggests the ancient cities in east Qinghai Province were likely built primarily for military defense, and may have also have been affected by climate change.

  6. Land degradation, government subsidy, and smallholders' conservation decision:the case of the loess plateau in China

    Institute of Scientific and Technical Information of China (English)

    SHI Min-jun(石敏俊); CHEN Kevin

    2004-01-01

    Land degradation is one of the severe environmental problems in China. In order to combat land degradation, a soil conservation program was introduced since 2000 to reduce soil erosion by converting slope-cultivated land into forestry and pasture. This paper represents the first systematic attempt to investigate the impact of the soil conservation program on land degradation in the loess plateau. The results indicate that the soil conservation program to convert slope fields into forest or pasture is an effective way to combat soil erosion. However, a subsidy that is higher than profit of land use activity of slope fields before their conversion into forest and pasture is needed to encourage farmers to join the conservation program. A policy measure to encourage and assist farmers to develop sedentary livestock by using crops produced from fields as well as fodder and forage grass from the converted slope fields might contribute to combat soil erosion. Increase in off-farm job opportunities may encourage households to reduce cultivation in slope fields. That implies a policy measure to encourage rural urbanization might contribute to combat soil erosion.

  7. [Effects of mulching and fertilization on winter wheat field soil moisture in dry highland region of Loess Plateau].

    Science.gov (United States)

    Wang, Xiao-Feng; Tian, Xiao-Hong; Chen, Zi-Hui; Chen, Hui-Lin; Wang, Zhao-Hui

    2009-05-01

    A field experiment was conducted in a winter wheat field in Weibei dry highland region of Loess Plateau to study the effects of different mulching and fertilization treatments on soil moisture regime. The treatments were 1) no fertilization, 2) conventional fertilization, 3) recommended fertilization, 4) recommended fertilization + manure, 5) recommended fertilization + plastic mulch on soil ridges, 6) recommended fertilization + plastic mulch on soil ridges and straw mulch in furrows, and 7) recommended fertilization + straw mulch on entire plot. Soil moisture content was determined regularly with a neutron probe. Among the treatments, recommended fertilization plus plastic mulch on soil ridges and straw mulch in furrows in dry season (spring) resulted in the greatest increase of soil water storage and maintained the storage to the critical stage crops needed, followed by recommended fertilization plus plastic mulch on soil ridges. These two treatments could store more precipitation in field, and would benefit the development of rainfed agriculture in dry highland region of Loess Plateau. As for recommended fertilization plus manure, it had the least increase of soil water storage, with a difference of 48.2 mm to the recommended fertilization plus plastic mulch on soil ridges and straw mulch in furrows in dry season.

  8. The Transformation of Agricultural Development towards a Sustainable Future from an Evolutionary View on the Chinese Loess Plateau: A Case Study of Fuxian County

    OpenAIRE

    Yanjun Guo; Yansui Liu; Qi Wen; Yurui Li

    2014-01-01

    The Loess Plateau in China receives lots of attention from around the world. The expansion of bad agricultural practices for hundreds of years aggravated the soil erosion on the Loess Plateau, however, and a lot of efforts were and are being made to reduce the serious soil erosion as well as regional poverty. Agricultural development of the Loess Plateau is still confronted with intricate challenges such as food concerns, environment concerns, and regional poverty. The strategy of developmen...

  9. 黄土高原半干旱区不同覆膜连作玉米产量的水分承载时限研究%The Time Loading Limitation of Continuous Cropping Maize Yield Under Different Plastic Film Mulching Modes in Semi-Arid Region of Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    谢军红; 柴强; 李玲玲; 张仁陟; 牛伊宁1; 罗珠珠; 蔡立群

    2015-01-01

    experiment in the second year, and it was 29.6%, 27.5% and 23.9% lower in the third year, this continuous soil water decrease practice resulted in soil water deficiency. With the prolongation of the time of continuous cultivation, soil desiccation appeared and has a negative effect on soil water sustainable use.[Conclusion]Under the same rainfall conditions, the completely mulched alternating narrow and wide ridges with furrow planting had a significant effect on increasing the yield, benefit and the WUE. Taking the sustainable use of water into account, 2 years is a suitable period of continuous cropping for the completely mulched alternating narrow and wide ridges with furrow planting, and 3 years is a suitable period of continuous cropping for complete mulching and flat-planting, half-mulching and flat-planting, flat-planting without mulching, respectively, in semi-arid region of Loess Plateau.%【目的】以黄土高原半干旱区有限降水持续高效利用为目标,研究不同覆膜方式下连作玉米(ZeaMay L.)的产量表现和水分利用特征,揭示其增产机理,明确不同覆膜方式下有利于土壤水分持续高效利用的连作年限,为试区高产、水分高效持续利用型玉米连作技术提供理论依据。【方法】以田间定位试验为基础,量化连作玉米农田土壤水分的年际平衡关系、产量稳定性;以持续高产和收获期不发生土壤干燥化为依据,确定适用于不同覆膜方式的玉米连作年限。【结果】3年试验结果表明,全膜双垄沟播具有良好的保墒、提高土壤水分有效性,利于协调关键生育时期土壤-作物的水分供需关系,提高产量和水分利用效率的作用。与半膜平作处理相比,全膜双垄沟播玉米的籽粒产量、水分利用效率分别提高了41.8%和33.4%,生物产量、单位耗水的干物质累积量、总产值、净产值、毫米水产值和产投比分别提高了21.8%、12.3%、31.2%、27.8%

  10. Streamflow Regime Variations Following Ecological Management on the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    Jianjun Zhang

    2015-12-01

    Full Text Available The continuous ecological management of the Loess Plateau is known throughout the world for two strategies: the integrated soil conservation project that began in the 1970s, and the “Grain for Green” project that began in the 1990s. Six sub-catchments nested in the Beiluo River basin were selected to investigate streamflow regime variations during the two project periods. The annual streamflow trends and change points were detected using a bootstrap-based Mann-Kendall test and Pettitt test. Annual streamflow (from the 1950s to 2011 exhibited significantly negative trends in five out of six catchments, varying from −0.15 to −0.30 mm/a. During the integrated soil conservation period, the annual streamflow was reduced due to high flow decreases (5% of time exceeded, whereas in the low flows (95% it increased in all sub-catchments. During the “Grain for Green” period, the annual streamflow decreased due to daily streamflow reductions at four stations. In addition to high flow and low flow decreases at the Wuqi and Liujiahe stations during the “Grain for Green” period, it is significant that the low flows continuously increased. Compared with trends from the forestry area, which includes the Zhangcunyi and Huangling stations, incremental annual streamflow reductions were observed in other sub-catchments, which can be linked to ecological management. This result implies that streamflow can be moderated by appropriate management options, even in semiarid areas. It was concluded that a stable streamflow regime can be achieved in vegetated areas, and streamflow moderation is dependent on ecological management practices.

  11. The eastern Tibetan Plateau geothermal belt, western China: Geology, geophysics, genesis, and hydrothermal system

    Science.gov (United States)

    Tang, Xianchun; Zhang, Jian; Pang, Zhonghe; Hu, Shengbiao; Tian, Jiao; Bao, Shujing

    2017-10-01

    The eastern Tibetan Plateau geothermal belt (ETGB), which is located in 98-102°E, 28-32°N, belongs to the eastern part of the Mediterranean-Himalayan geothermal belt. Recently, about 248 natural hot springs have been found in the ETGB. > 60% of these springs have temperatures of > 40 °C, and 11 springs have temperature above the local water boiling point. Using the helium isotopic data, gravity, magnetic and seismic data, we analyzed the thermal structure and the relationship between hydrothermal activity and geothermal dynamics of the ETGB. Results show that: (1) the 248 springs can be divided into three geothermal fields: Kangding-Luhuo geothermal field (KGF), Litang-Ganzi geothermal field (LGF) and Batang-Xiangcheng geothermal field (BGF). The BGF and LGF have hot crust and warm mantle, and are characterized by the higher heat flux (66.26 mW/m2), and higher ratios of crust-derived heat flux to total flux (47.46-60.62%). The KGF has cool crust and hot mantle, and is characterized by the higher heat flux and lower Qc/Qm; (2) there is a relatively 4-6 m higher gravimetric geoid anomaly dome which is corresponding with the ETGB. And in hydrothermal activity areas of the BGF and LGF, there is a northwest - southeast-trending tensile stress area and the upper-middle crust uplift area; (3) an abnormal layer exists in the middle-lower crust at a depth of 13-30 km beneath the ETGB, and this layer is 8-10 km thick and is characterized by lower velocity (Vp 2.5), high conductivity ( 10 Ω·m) and high temperature (850-1000 °C). Finally, based on the heat source and geological and geophysical background, we propose Kangding-type and Batang-type hydrothermal system models in the ETGB.

  12. [Climatic suitability of single cropping rice planting region in China].

    Science.gov (United States)

    Duan, Ju-Qi; Zhou, Guang-Sheng

    2012-02-01

    To clarify the leading climate factors affecting the distribution of single cropping rice planting region in China at national and annual temporal scales and to reveal the potential distribution and climatic suitability divisions of this planting region in China could not only provide scientific basis for optimizing the allocation of single cropping rice production, modifying planting pattern, and introducing fine varieties, but also ensure the food security of China. In this paper, the potential climate factors affecting the single cropping rice distribution in China at regional and annual scales were selected from related literatures, and the single cropping rice geographic information from the national agro-meteorological observation stations of China Meteorological Administration (CMA), together with the maximum entropy model (MaxEnt) and spatial analyst function of Arc-GIS software, were adopted to clarify the leading climate factors affecting the potential distribution of single cropping rice planting region in China, and to construct a model about the relationships between the potential distribution of the planting region and the climate. The results showed that annual precipitation, moisture index, and days of not less than 18 degrees C stably were the leading climate factors affecting the potential distribution of single cropping rice planting region in China, with their cumulative contribution rate reached 94.5% of all candidate climate factors. The model constructed in this paper could well simulate the potential distribution of single cropping rice planting region in China. According to the appearance frequency, the low, medium and high climatic suitability divisions of single cropping rice planting region in China were clarified, and the climate characteristics of the planting region in each climatic suitability division were analyzed.

  13. A new subfamily of the grasshopper (Orthoptera: Acridoidea:Gomphoceridae) from the Tibetan Plateau of China

    Institute of Scientific and Technical Information of China (English)

    Dao-Chuan Zhang; Yu-Long Zhang; Xiang-Chu Yin

    2012-01-01

    This paper reports a new subfamily,a new genus and a new species,that is,Pacrinae subfam.nov.,Pacris gen.nov and Pacris xizangensis sp.nov in Gomphoceridae.The new subfamily is allied to Orinhippinae of Gomphoceridae and it differs from the latter by wings and tympanum absent.The new genus is similar to Orinhippus Uvarov,1921 but differs from the latter in: (i) foveolae absent; (ii) tegmina absent; (iii) tympanum absent;(iv) hind margin ofpronotum with incised in the middle.Type specimens are deposited in the Museum of Hebei University,Baoding,China.

  14. A drought hazard assessment index based on the VIC-PDSI model and its application on the Loess Plateau, China

    Science.gov (United States)

    Zhang, Baoqing; Wu, Pute; Zhao, Xining; Wang, Yubao; Gao, Xiaodong; Cao, Xinchun

    2013-10-01

    Drought is a complex natural hazard that is poorly understood and difficult to assess. This paper describes a VIC-PDSI model approach to understanding drought in which the Variable Infiltration Capacity (VIC) Model was combined with the Palmer Drought Severity Index (PDSI). Simulated results obtained using the VIC model were used to replace the output of the more conventional two-layer bucket-type model for hydrological accounting, and a two-class-based procedure for calibrating the characteristic climate coefficient ( K j ) was introduced to allow for a more reliable computation of the PDSI. The VIC-PDSI model was used in conjunction with GIS technology to create a new drought assessment index (DAI) that provides a comprehensive overview of drought duration, intensity, frequency, and spatial extent. This new index was applied to drought hazard assessment across six subregions of the whole Loess Plateau. The results show that the DAI over the whole Loess Plateau ranged between 11 and 26 (the greater value of the DAI means the more severe of the drought hazard level). The drought hazards in the upper reaches of Yellow River were more severe than that in the middle reaches. The drought prone regions over the study area were mainly concentrated in Inner Mongolian small rivers, Zuli and Qingshui Rivers basin, while the drought hazards in the drainage area between Hekouzhen-Longmen and Weihe River basin were relatively mild during 1971-2010. The most serious drought vulnerabilities were associated with the area around Lanzhou, Zhongning, and Yinchuan, where the development of water-saving irrigation is the most direct and effective way to defend against and reduce losses from drought. For the relatively humid regions, it will be necessary to establish the rainwater harvesting systems, which could help to relieve the risk of water shortage and guarantee regional food security. Due to the DAI considers the multiple characteristic of drought duration, intensity, frequency

  15. Effects of Litter on Seedling Emergence and Seed Persistence of Three Common Species on the Loess Plateau in Northwestern China.

    Science.gov (United States)

    Zhang, Rui; Hu, Xiaowen; Baskin, Jerry M; Baskin, Carol C; Wang, Yanrong

    2017-01-01

    Litter accumulation resulting from land use change (enclosure) is one of the key variables influencing seedling recruitment and consequently the regeneration of plant populations and seed persistence in the soil seed bank. A better understanding of the effects of litter on seed germination and seedling emergence is crucial for developing a new set of indicators for grassland ecosystem health and for grassland management policy. We investigated the effects of seed position in litter and amount of litter covering the seed on seedling emergence and seed persistence of three common species on the Loess Plateau in northwestern China. Seed position beneath the litter layer provided a suitable environment for seedling emergence of the three species. A moderate amount of litter (160 g/m(2)) was beneficial for seedling emergence of the small-seeded species Stipa bungeana and Lespedeza davurica from seeds from beneath the litter layer. The large-seeded species Setaria glauca was more tolerant of a high amount of litter (240 g/m(2)) than the two small-seeded species. Seed persistence in the soil differed among the three species and also was affected by seed position in litter and amount of litter cover. The proportion of viable seeds of Stipa bungeana and Setaria glauca on top of the litter layer increased with an increase in amount of litter. Seedling emergence and seed persistence varied significantly among species, amount of litter and seed position in litter. A moderate amount of litter and seeds positioned beneath the litter layer were better for seedling recruitment than for those on top of the litter layer. A high amount of litter was more favorable for persistence of seeds positioned on top of the litter than for those beneath the litter. Our study showed that maintaining litter amount between 80 and 160 g/m(2) is optimal for S. bungeana dominated grassland on the Loess Plateau. We suggest that litter amount can serve as a guide for monitoring and managing grassland

  16. Comparison of methanogen diversity of yak (Bos grunniens and cattle (Bos taurus from the Qinghai-Tibetan plateau, China

    Directory of Open Access Journals (Sweden)

    Huang Xiao

    2012-10-01

    Full Text Available Abstract Background Methane emissions by methanogen from livestock ruminants have significantly contributed to the agricultural greenhouse gas effect. It is worthwhile to compare methanogen from “energy-saving” animal (yak and normal animal (cattle in order to investigate the link between methanogen structure and low methane production. Results Diversity of methanogens from the yak and cattle rumen was investigated by analysis of 16S rRNA gene sequences from rumen digesta samples from four yaks (209 clones and four cattle (205 clones from the Qinghai-Tibetan Plateau area (QTP. Overall, a total of 414 clones (i.e. sequences were examined and assigned to 95 operational taxonomic units (OTUs using MOTHUR, based upon a 98% species-level identity criterion. Forty-six OTUs were unique to the yak clone library and 34 OTUs were unique to the cattle clone library, while 15 OTUs were found in both libraries. Of the 95 OTUs, 93 putative new species were identified. Sequences belonging to the Thermoplasmatales-affiliated Linage C (TALC were found to dominate in both libraries, accounting for 80.9% and 62.9% of the sequences from the yak and cattle clone libraries, respectively. Sequences belonging to the Methanobacteriales represented the second largest clade in both libraries. However, Methanobrevibacter wolinii (QTPC 110 was only found in the cattle library. The number of clones from the order Methanomicrobiales was greater in cattle than in the yak clone library. Although the Shannon index value indicated similar diversity between the two libraries, the Libshuff analysis indicated that the methanogen community structure of the yak was significantly different than those from cattle. Conclusion This study revealed for the first time the molecular diversity of methanogen community in yaks and cattle in Qinghai-Tibetan Plateau area in China. From the analysis, we conclude that yaks have a unique rumen microbial ecosystem that is significantly different

  17. Spatial variability of soil hydraulic properties on a steep slope in the loess plateau of China Variabilidade espacial de propriedades hídricas do solo de uma encosta do "Loess Plateau" da China

    Directory of Open Access Journals (Sweden)

    Wei Hu

    2008-01-01

    Full Text Available The understanding of the structure of the spatial variability of soil surface hydraulic properties on steep slopes is important for modeling infiltration and runoff processes. The objective of this study was to investigate the spatial variability of these properties on a steep slope of the Loess Plateau in northwest China. A 9600 m² area was systematically sampled in a grid of 106 points spaced 10 m x 10 m. Hydraulic properties were determined with a disc infiltrometer under multiple pressure heads (-15, -9, -6, -3, 0 cm at each sample point. Classical and geo-statistical methods were used for data analysis. The results indicated that the variation of Gardner's a and hydraulic conductivities at all applied pressure heads was moderate and the heterogeneity for hydraulic conductivities increased as the applied pressure head increased. Along the slope, hydraulic conductivities generally decreased downwards, while the Gardner's a fluctuated slightly. The Gardner's a of the shaded aspect of the slope was greater than that of the sunny aspect. The hydraulic conductivities of the shaded aspect were greater at higher pressure heads as compared to the sunny aspect, but lower than those of the sunny aspect at lower pressure heads. Correlation analysis showed a negative correlation between hydraulic conductivity and soil organic matter and clay (A compreensão da estrutura da variabilidade especial das propriedades hidráulicas do solo de encostas íngremes é importante na modelagem dos processos de infiltração e de escoamento superficial da água. O objetivo deste estudo foi investigar a variabilidade destas propriedades em uma encosta íngreme do "Loess Plateau" do noroeste da China. Uma área de 9600 m² foi sistematicamente amostrada em um grid de 106 pontos espaçados de 10 m x 10 m. As propriedades hídricas foram determinadas com um infiltrômetro de disco operando sob múltiplas cargas hidráulicas (-15, -9, -6, -3, 0 cm em cada ponto de

  18. Phylogeographic History of Atraphaxis Plants in Arid Northern China and the Origin of A. bracteata in the Loess Plateau

    Science.gov (United States)

    Xu, Zhe; Zhang, Ming-Li; Cohen, James I.

    2016-01-01

    In China, species of Atraphaxis (Polygonaceae) primarily inhabit arid zones across temperate steppe and desert regions. The complex geologic history (e.g., expansion of deserts) and extreme climate shifts of the region appear to have played an important role in shaping the phylogeography of Atraphaxis. The present study focuses on species-level phylogeographic patterns of Atraphaxis in China, with the goal of determining the impact of past environmental changes, in northern China, on the evolutionary history of the genus. Five hundred and sixty-four individuals distributed among 71 populations of 11 species of Atraphaxis from across the geographic range of the genus were studied using sequence data from two plastid spacers, psbK-psbI and psbB-psbH. The results demonstrate that most chloroplast haplotypes are species-specific, except for some present among widespread species. The phylogeny of Atraphaxis was well structured, and molecular dating analyses suggest that the main divergence events occurred during the late Pliocene and Pleistocene (5.73–0.03 million years ago). The statistical dispersal-vicariance analysis (S-DIVA) results provide evidence that phylogeographic patterns for the genus were characterized by both vicariance events and regional dispersal. The presented data suggest that the rapid expansion of deserts and climatic changes in northern China during the late Pliocene and Pleistocene have driven the diversification and spread of Atraphaxis in the region. The expansion of the Tengger Desert provided appropriate conditions for the origin of A. bracteata. Additionally, a contact zone in the north of the Hexi Corridor was identified as having played a significant role as a migratory route for species in adjacent areas. PMID:27656885

  19. Soil Infiltration Characteristics in Agroforestry Systems and Their Relationships with the Temporal Distribution of Rainfall on the Loess Plateau in China.

    Science.gov (United States)

    Wang, Lai; Zhong, Chonggao; Gao, Pengxiang; Xi, Weimin; Zhang, Shuoxin

    2015-01-01

    Many previous studies have shown that land use patterns are the main factors influencing soil infiltration. Thus, increasing soil infiltration and reducing runoff are crucial for soil and water conservation, especially in semi-arid environments. To explore the effects of agroforestry systems on soil infiltration and associated properties in a semi-arid area of the Loess Plateau in China, we compared three plant systems: a walnut (Juglans regia) monoculture system (JRMS), a wheat (Triticum aestivum) monoculture system (TAMS), and a walnut-wheat alley cropping system (JTACS) over a period of 11 years. Our results showed that the JTACS facilitated infiltration, and its infiltration rate temporal distribution showed a stronger relationship coupled with the rainfall temporal distribution compared with the two monoculture systems during the growing season. However, the effect of JTACS on the infiltration capacity was only significant in shallow soil layer, i.e., the 0-40 cm soil depth. Within JTACS, the speed of the wetting front's downward movement was significantly faster than that in the two monoculture systems when the amount of rainfall and its intensity were higher. The soil infiltration rate was improved, and the two peaks of soil infiltration rate temporal distribution and the rainfall temporal distribution coupled in rainy season in the alley cropping system, which has an important significance in soil and water conservation. The results of this empirical study provide new insights into the sustainability of agroforestry, which may help farmers select rational planting patterns in this region, as well as other regions with similar climatic and environmental characteristics throughout the world.

  20. Soil Infiltration Characteristics in Agroforestry Systems and Their Relationships with the Temporal Distribution of Rainfall on the Loess Plateau in China.

    Directory of Open Access Journals (Sweden)

    Lai Wang

    Full Text Available Many previous studies have shown that land use patterns are the main factors influencing soil infiltration. Thus, increasing soil infiltration and reducing runoff are crucial for soil and water conservation, especially in semi-arid environments. To explore the effects of agroforestry systems on soil infiltration and associated properties in a semi-arid area of the Loess Plateau in China, we compared three plant systems: a walnut (Juglans regia monoculture system (JRMS, a wheat (Triticum aestivum monoculture system (TAMS, and a walnut-wheat alley cropping system (JTACS over a period of 11 years. Our results showed that the JTACS facilitated infiltration, and its infiltration rate temporal distribution showed a stronger relationship coupled with the rainfall temporal distribution compared with the two monoculture systems during the growing season. However, the effect of JTACS on the infiltration capacity was only significant in shallow soil layer, i.e., the 0-40 cm soil depth. Within JTACS, the speed of the wetting front's downward movement was significantly faster than that in the two monoculture systems when the amount of rainfall and its intensity were higher. The soil infiltration rate was improved, and the two peaks of soil infiltration rate temporal distribution and the rainfall temporal distribution coupled in rainy season in the alley cropping system, which has an important significance in soil and water conservation. The results of this empirical study provide new insights into the sustainability of agroforestry, which may help farmers select rational planting patterns in this region, as well as other regions with similar climatic and environmental characteristics throughout the world.

  1. Contourite systems in the region of the southern São Paulo Plateau escarpment, South Atlantic

    Science.gov (United States)

    Borisov, D. G.; Murdmaa, I. O.; Ivanova, E. V.; Levchenko, O. V.; Yutsis, V. V.; Frantseva, T. N.

    2013-07-01

    Seismoacoustic investigations with a high-resolution parametric echo-sounder "SES 2000 deep" carried out on cruises 33, 35, and 37 of the R/V Akademik Ioffe revealed several erosional-depositional contourite systems on the São Paulo Plateau escarpment and its toe in the South Atlantic. Two contourite terraces related to interfaces between different water masses are observable on the escarpment. These terraces presumably reflect the activity of internal waves and turbulent eddies. The São Paulo contourite channel and genetically related drift are traceable along the escarpment toe. Changes in planktonic foraminiferal assemblages in Core AI-2563 retrieved from the summit of the São Paulo contourite drift suggest a shallowing of the Weddell Sea Deep Water mass during glacial times. It is established that the contour current of the Weddell Sea Deep Water and Lower Circumpolar Water considerably affect the formation of contourite depositional systems on the escarpment and its toe.

  2. RUNOFF GENERATION CHARACTERISTICS IN TYPICAL EROSION REGIONS ON THE LOESS PLATEAU

    Institute of Scientific and Technical Information of China (English)

    Li CHEN; Qingquan LIU; Jiachun LI

    2001-01-01

    This paper presents a process-based model for runoff generation on slopes. One dimensional kinematic wave theory combined with the revised Green-Ampt infiltration formula is applied in the model. According to the characteristics of soil and rainfall in the Loess Plateau area, six types of storm are defined, and among them three typical erosion zones that have different values of representative parameters are chosen to simulate the runoff generation processes. The primary hydraulic characteristics of the runoff generation, such as unit discharge, runoff depth, flow velocity, shear stress and ratio of runoff generation, are obtained and analyzed. The results demonstrate that the different erosion characteristics are related to different runoff generation zones.

  3. Balancing regional industrial development: analysis on regional disparity of China's industrial emissions and policy implications

    DEFF Research Database (Denmark)

    Liang, Hanwei; Dong, Liang; Luo, Xiao;

    2016-01-01

    Efficient industrial emissions mitigation strategy is critical for China's national action on climate change and sustainable development, considering its rapid industrialization. Regional disparity brings difficulties and uncertainties to policy implementation in China. Therefore, an investigatio...... and an environmental inequity. Regional oriented mitigation strategies are required to balance regional disparity, so as to realize the industrial emission control policy under the “equity and efficiency” principle.......Efficient industrial emissions mitigation strategy is critical for China's national action on climate change and sustainable development, considering its rapid industrialization. Regional disparity brings difficulties and uncertainties to policy implementation in China. Therefore, an investigation...... on the regional features of industrial emissions is critical to better decision makings. While to date, related studies have been rather few. This paper applies a spatial analysis on regional features of China's industrial emissions (SO2, NOx and PM2.5 and CO2 emission) in 31 provinces. Spatial autocorrelation...

  4. Delineation of eco—geographic regional system of China

    Institute of Scientific and Technical Information of China (English)

    WUShaohong; YANGOinye; ZHENGDu

    2003-01-01

    Eco-geographic regionalization has been one of the most important topics in China's regionalization researches since the end of the 20th century. It is a major ecosystem in geographic zonality. A hierarchical system, which is formed by division or combination of natural features based on geographic relativity and comparison of major ecosystem factors (including biological and non-biological) and geographic zonality, is called eco-geographic regional system. This paper introduces process of China's regionalization development. The first level unit, temperature zone, is delineated with main criteria of temperature. The second level unit, humidity region, is based on criteria of water/moisture states. The third level unit, natural region, is divided according to medium geomorphologic units. Vegetation types and soils are applied as supplementary criteria to indicate temperature and water/moisture states. Mapping process from qualitative to quantitative and China's eco-geographic regional system are also explained in this paper.

  5. China, The Regional Hegemon with Global Reach

    Science.gov (United States)

    2011-03-07

    with the transnational and environmental threats ( HIV /AIDs, pandemics, environmental issues) that could have drastic effects globally. President...multiple developing countries afloat.22 In December 2010 China signed a strategic bilateral deal with Venezuela . This alliance solidified a pact where... Venezuela sends 600,000 barrels a day to China in exchange for China’s investment in mining and energy production.23 Bilateral deals like this are

  6. Studying Tertiary System in Oil and Gas Regions of China

    Institute of Scientific and Technical Information of China (English)

    Kong Yaoxian

    1994-01-01

    @@ In order to obtain potential resources in the Tertiary System and provide scientific data for oil and gas exploration, the CNPC and CNOOC had drawn up a project to study the Tertiary System in oil and gas regions of China.

  7. Phylogeography and allopatric divergence of cypress species (Cupressus L. in the Qinghai-Tibetan Plateau and adjacent regions

    Directory of Open Access Journals (Sweden)

    Ciren Zhaxi

    2010-06-01

    Full Text Available Abstract Background Although allopatric speciation is viewed as the most common way in which species originate, allopatric divergence among a group of closely related species has rarely been examined at the population level through phylogeographic analysis. Here we report such a case study on eight putative cypress (Cupressus species, which each have a mainly allopatric distribution in the Qinghai-Tibetan Plateau (QTP and adjacent regions. The analysis involved sequencing three plastid DNA fragments (trnD-trnT, trnS-trnG and trnL-trnF in 371 individuals sampled from populations at 66 localities. Results Both phylogenetic and network analyses showed that most DNA haplotypes recovered or haplotype-clustered lineages resolved were largely species-specific. Across all species, significant phylogeographic structure (NST >GST, P C. duclouxiana and C. chengiana, which are distributed in the eastern QTP region, contained more haplotypes and higher diversity than five species with restricted distributions in the western highlands of the QTP. The remaining species, C. funebris, is widely cultivated and contained very little cpDNA diversity. Conclusions It is concluded that the formation of high mountain barriers separating deep valleys in the QTP and adjacent regions caused by various uplifts of the plateau since the early Miocene most likely promoted allopatric divergence in Cupressus by restricting gene flow and fixing local, species-specific haplotypes in geographically isolated populations. The low levels of intraspecific diversity present in most species might stem from population bottlenecks brought about by recurrent periods of unfavorable climate and more recently by the negative impacts of human activities on species' distributions. Our findings shed new light on the importance of geographical isolation caused by the uplift of the QTP on the development of high plant species diversity in the QTP biodiversity hotspot.

  8. Carbon Storage Patterns of Caragana korshinskii in Areas of Reduced Environmental Moisture on the Loess Plateau, China

    Science.gov (United States)

    Gong, Chunmei; Bai, Juan; Wang, Junhui; Zhou, Yulu; Kang, Tai; Wang, Jiajia; Hu, Congxia; Guo, Hongbo; Chen, Peilei; Xie, Pei; Li, Yuanfeng

    2016-07-01

    Precipitation patterns are influenced by climate change and profoundly alter the carbon sequestration potential of ecosystems. Carbon uptake by shrubbery alone accounts for approximately one-third of the total carbon sink; however, whether such uptake is altered by reduced precipitation is unclear. In this study, five experimental sites characterised by gradual reductions in precipitation from south to north across the Loess Plateau were used to evaluate the Caragana korshinskii’s functional and physiological features, particularly its carbon fixation capacity, as well as the relationships among these features. We found the improved net CO2 assimilation rates and inhibited transpiration at the north leaf were caused by lower canopy stomatal conductance, which enhanced the instantaneous water use efficiency and promoted plant biomass as well as carbon accumulation. Regional-scale precipitation reductions over a certain range triggered a distinct increase in the shrub’s organic carbon storage with an inevitable decrease in the soil’s organic carbon storage. Our results confirm C. korshinskii is the optimal dominant species for the reconstruction of fragile dryland ecosystems. The patterns of organic carbon storage associated with this shrub occurred mostly in the soil at wetter sites, and in the branches and leaves at drier sites across the arid and semi-arid region.

  9. Groundwater recharge mechanism in an integrated tableland of the Loess Plateau, northern China: insights from environmental tracers

    Science.gov (United States)

    Huang, Tianming; Pang, Zhonghe; Liu, Jilai; Ma, Jinzhu; Gates, John

    2017-05-01

    Assessing groundwater recharge characteristics (recharge rate, history, mechanisms (piston and preferential flow)) and groundwater age in arid and semi-arid environments remains a difficult but important research frontier. Such assessments are particularly important when the unsaturated zone (UZ) is thick and the recharge rate is limited. This study combined evaluations of the thick UZ with those of the saturated zone and used multiple tracers, such as Cl, NO3, Br, 2H, 18O, 13C, 3H and 14C, to study groundwater recharge characteristics in an integrated loess tableland in the Loess Plateau, China, where precipitation infiltration is the only recharge source for shallow groundwater. The results indicate that diffuse recharge beneath crops, as the main land use of the study area, is 55-71 mm yr-1 based on the chloride mass balance of soil profiles. The length of time required for annual precipitation to reach the water table is 160-400 yrs. The groundwater is all pre-modern water and paleowater, with corrected 14C age ranging from 136 to 23,412 yrs. Most of the water that eventually becomes recharge originally infiltrated in July-September. The Cl and NO3 contents in the upper UZ are considerably higher than those in the deep UZ and shallow groundwater because of recent human activities. The shallow groundwater has not been in hydraulic equilibrium with present near-surface boundary conditions. The homogeneous material of the UZ and relatively old groundwater age imply that piston flow is the dominant recharge mechanism for the shallow groundwater in the tableland.

  10. Nutrient distribution and accumulation patterns of natural secondary forests in the Loess Plateau of Shanxi Province, northern China

    Institute of Scientific and Technical Information of China (English)

    Xiaojuan ZHANG; Tianxing WEI; Libo JING; Na YIN; Yanhui LIU

    2009-01-01

    We studied the biomass and its allocation in natural secondary forests, as well as the amounts, accumulation and distribution of nutrient elements (N, P, K, Ca and Mg) in sample plots established in the Loess Plateau in Shanxi Province, northern China. The results show that biomass in natural secondary forests amounted to 36.09 t/hm2,. of which the tree layer accounted for 46%, the shrub layer for 29%, the herb layer for 13% and the litter layer for 12%. The total storage of the five nutrient elements is 1089.82 kg/hm2. Nutrient storage in the tree layer is the largest, at 41%. The sequence of storage of the elements varied among different layers and is given as follows: shrub layer 31.27%, herb layer 12.55% and litter layer 15.36%. The accumulation of nutrient elements in the tree layer, ordered from high to low, is: branches > roots > stems > bark > leaves. The total storage of the five nutrient elements in the soil is 634.97 t/hm2, where the accumulation of the nutrients accounts for 95.32% (N), 99.64% (P), 99.91% (K), 99.84% (Ca) and 99.95% (Mg) of the total amounts. The accumulation coefficients of different organs in the tree layer are, from high to low: leaves > branches > roots > bark > stems. The accumulation coefficients in the different layers are listed as follows: shrub layer > tree layer > herb layer and for the elements as: N > P > Ca > K > Mg.

  11. A 368-year maximum temperature reconstruction based on tree-ring data in the northwestern Sichuan Plateau (NWSP), China

    Science.gov (United States)

    Zhu, Liangjun; Zhang, Yuandong; Li, Zongshan; Guo, Binde; Wang, Xiaochun

    2016-07-01

    We present a reconstruction of July-August mean maximum temperature variability based on a chronology of tree-ring widths over the period AD 1646-2013 in the northern part of the northwestern Sichuan Plateau (NWSP), China. A regression model explains 37.1 % of the variance of July-August mean maximum temperature during the calibration period from 1954 to 2012. Compared with nearby temperature reconstructions and gridded land surface temperature data, our temperature reconstruction had high spatial representativeness. Seven major cold periods were identified (1708-1711, 1765-1769, 1818-1821, 1824-1828, 1832-1836, 1839-1842, and 1869-1877), and three major warm periods occurred in 1655-1668, 1719-1730, and 1858-1859 from this reconstruction. The typical Little Ice Age climate can also be well represented in our reconstruction and clearly ended with climatic amelioration at the late of the 19th century. The 17th and 19th centuries were cold with more extreme cold years, while the 18th and 20th centuries were warm with less extreme cold years. Moreover, the 20th century rapid warming was not obvious in the NWSP mean maximum temperature reconstruction, which implied that mean maximum temperature might play an important and different role in global change as unique temperature indicators. Multi-taper method (MTM) spectral analysis revealed significant periodicities of 170-, 49-114-, 25-32-, 5.7-, 4.6-4.7-, 3.0-3.1-, 2.5-, and 2.1-2.3-year quasi-cycles at a 95 % confidence level in our reconstruction. Overall, the mean maximum temperature variability in the NWSP may be associated with global land-sea atmospheric circulation (e.g., ENSO, PDO, or AMO) as well as solar and volcanic forcing.

  12. A case study of spatial heterogeneity of soil moisture in the Loess Plateau,western China:A geostatistical approach

    Institute of Scientific and Technical Information of China (English)

    BI Huaxing; LI Xiaoyin; LIU Xin; GUO Mengxia; LI Jun

    2009-01-01

    Soil moisture distribution shows highly variation both spatially and temporally.This study assesses the spatial heterogeneity of soil moisture on a hill-slope scale in the Loess Plateau in West China by using a geostatistical approach.Soil moisture was measured by time-domain reflectometry (TDR) in 313 samples.Two kinds of sampling scales were used (2 × 2 m and 20 × 20m) at two soil layers (0-30 cm and 30-450 cm).The general characteristics of soil moisture were analyzed by a classical statistics method,and the spatial heterogeneity of soil moisture was analyzed using a geostatistical approach.The results showed that the spherical model is the best-fit model to simulate soil moisture on the experimental hill-slope.The parameters of this model indicated that the spatial dependence of soil moisture in the selected hill-slope was moderate.Even the 2 × 2 m sampling scale was too coarse to show the detailed spatial variances of soil moisture in this area.The dependent distance increased from 27.4 m to 494.16 m as the sampling scale became coarse (from 2 ×2 m to 20 × 20 m).A map of soil moisture was generated by using original soil moisture data and interpolated values determined by the Kriging method.The average soil moisture (area weighted) in the different layers of soil was calculated on the basis of this map (10.94% for the 0-30 cm soil layer,11.88% for the 30-60 em soil layer).This average soil moisture is lower than the corresponding average effective soil moisture,which suggests that the soil moisture is not sufficient to support vegetation in this area.

  13. Effects of elevated temperature and CO2 concentration on photosynthesis of the alpine plants in Zoige Plateau, China

    Science.gov (United States)

    Zijuan, Zhou; Peixi, Su; Rui, Shi; Tingting, Xie

    2017-04-01

    Increasing temperature and carbon dioxide concentration are the important aspects of global climate change. Alpine ecosystem response to global change was more sensitive and rapid than other ecosystems. Increases in temperature and atmospheric CO2concentrations have strong impacts on plant physiology. Photosynthesis is the basis for plant growth and the decisive factor for the level of productivity, and also is a very sensitive physiological process to climate change. In this study, we examined the interactive effects of elevated temperature and atmospheric CO2 concentration on the light response of photosynthesis in two alpine plants Elymus nutans and Potentilla anserine, which were widely distributed in alpine meadow in the Zoige Plateau, China. We set up as follows: the control (Ta 20˚ C, CO2 380μmolṡmol-1), elevated temperature (Ta 25˚ C, CO2 380 μmolṡmol-1), elevated CO2 concentration (Ta 20˚ C, CO2 700μmolṡmol-1), elevated temperature and CO2 concentration (Ta 25˚ C, CO2 700μmolṡmol-1). The results showed that compared to P. anserine, E. nutans had a higher maximum net photosynthetic rate (Pnmax), light saturation point (LSP) and apparent quantum yield (AQY) in the control. Elevated temperature increased the Pnmaxand LSP values in P. anserine, while Pnmaxand LSP were decreased in E. nutans. Elevated CO2 increased the Pnmaxand LSP values in E. nutans and P. anserine, while the light compensation point (LCP) decreased; Elevated both temperature and CO2, the Pnmaxand LSP were all increased for E. nutans and P. anserine, but did not significantly affect AQY. We concluded that although elevated temperature had a photoinhibition for E. nutans, the interaction of short-term elevated CO2 concentration and temperature can improve the photosynthetic capacity of alpine plants. Key Words: elevated temperature; CO2 concentration; light response; alpine plants

  14. Regional Performance of China's Banks: Evidence from Industrial and Commercial Bank of China

    OpenAIRE

    2015-01-01

    This paper investigates regional performances of China's and the world's largest commercial bank: the Industrial and Commercial Bank of China (ICBC), by its spatial patterns and geographical distribution of deposits. Moran I of Geoda software and the Local Indicators of Spatial Association (LISA) are applied. Empirical evidence shows that overall performances of ICBC depended consistently on Yangtze River Delta and Bohai Sea region while performances of other regions were relatively lower-per...

  15. Total exhumation across the Beichuan fault in the Longmen Shan (eastern Tibetan plateau, China): Constraints from petrology and thermobarometry

    Science.gov (United States)

    Airaghi, Laura; de Sigoyer, Julia; Lanari, Pierre; Guillot, Stéphane; Vidal, Olivier; Monié, Patrick; Sautter, Benjamin; Tan, Xibin

    2017-06-01

    The deep structure and deformation mechanisms of the Longmen Shan thrust belt (Sichuan, China), at the eastern border of the Tibetan plateau, were largely debated after the devastating Mw 7.9 Wenchuan earthquake (2008). Recent geophysical studies and field investigations have been focused on the active motion of the major Beichuan fault, which ruptured during the earthquake. However, the total exhumation across the fault still remains unclear. In the hanging wall of the Beichuan fault, the South China block is exhumed in the Pengguan massif. Close to the Beichuan fault, the rocks of the Pengguan massif underwent greenschist facies metamorphism associated with brittle-ductile deformation. No metamorphism is observed in the footwall of the fault. In this study, we characterize and date the metamorphic history recorded in the hanging wall of the Beichuan fault in order to constrain the depth and timing of exhumation of the rocks of the Pengguan massif along the fault. A high-resolution petrological approach involving chemical analyses and X-ray maps was used to analyze the micrometric metamorphic minerals. The P-T conditions of the greenschist facies metamorphic event were estimated by an inverse multi-equilibrium thermodynamic approach. The results, 280 ± 30 °C and 7 ± 1 kbar, suggest that the rocks of the Pengguan massif were exhumed from ca. 20 km depth. Our results underline the importance of the thrusting component in the long-term behavior of the Beichuan fault and provide a minimal depth at which the fault is rooted. In situ laser ablation 40Ar/39Ar dating of metamorphic white mica revealed that the greenschist overprint occurred at 135-140 Ma. The Pengguan massif was therefore partially thrusted along the Beichuan fault during the Lower Cretaceous, long before the Eocene-Miocene exhumation phase which is well-constrained by low-temperature thermochronology. Our results provide the first independent depth information for the exhumation history of the

  16. Magnetostratigraphic age and monsoonal evolution recorded by the thickest Quaternary loess deposit of the Lanzhou region, western Chinese Loess Plateau

    Science.gov (United States)

    Zhang, Jun; Li, Jijun; Guo, Benhong; Ma, Zhenhua; Li, Xiaomiao; Ye, Xiyan; Yu, Hao; Liu, Jia; Yang, Cheng; Zhang, Shengda; Song, Chunhui; Hui, Zhengchuang; Peng, Tingjiang

    2016-05-01

    The loess-paleosol sequences of the Chinese Loess Plateau (CLP) are major paleoclimatic archives which document the evolution of the East Asian Monsoon (EAM) and changes in the Northern Hemisphere ice sheets during the Quaternary glacial-interglacial cycles. However, the mechanisms regulating the trend of EAM variations on a tectonic scale are unclear. The loess deposits of the western CLP, which have a close relationship with tectonics and climate, are much better-suited to exploring these mechanisms than those of the central CLP. However, studies of long-term EAM evolution from the western CLP have been hindered by the lack of long, accurately-dated sequences with high sediment accumulation rates. Here, we address this problem via high resolution magnetostratigraphic, magnetic susceptibility and grain-size analyses of a 416.2 m-long drill core located at Xijin Village, near Lanzhou. Paleomagnetic dating indicates that the basal age of the Xijin loess is ∼2.2 Ma. The χ and grain-size records reveal that the East Asian Summer Monsoon (EASM) and East Asian Winter Monsoon (EAWM) strengthened synchronously at ∼1.24 Ma. Subsequently, during interglacial periods, the EASM began to penetrate, and then dominate, in the Lanzhou region. This was followed by two stepwise uptrends, commencing at ∼0.87 and ∼0.62 Ma, which resulted in an increasingly moist interglacial climate in the region. We suggest that the uplift of the Tibetan Plateau was largely responsible for these three stepwise enhancements of the EASM. Overall, however, the long-term trend of strengthening in EAWM in the area may have been primarily caused by long-term global cooling from the Late Pliocene onwards.

  17. A Multi-regional CGE Model for China

    Science.gov (United States)

    Li, Na; Shi, Minjun; Wang, Fei

    With the development of China’s economy, the regional diversity and interregional economic linkage have become more and more remarkable and been two important factors to study China’s national and regional economy. Based on the multi-regional input-output table for China, this paper develops a multi-regional CGE (MRCGE) model for China that is expected to provide a useful tool for analysis of regional economy and regional policies. This model depicts regional diversities on scale and structure and interregional economic linkages, i.e. commodity flow, labor flow and capital flow. As an application of this model, this paper designs to increase the investment for Northwestern region to reveal the important effect that comes from the regional differences and linkages.

  18. Theory and Practice of Marine Regional Management in China

    Institute of Scientific and Technical Information of China (English)

    Shangjie; JI; Qunzhen; QU

    2014-01-01

    With the development of marine economy in coastal provinces and cities,there comes a series of environmental problems. Marine regional management,as a completely new marine management mode,transforms traditional management mode and can protect marine ecosystem. Thus,the marine regional management is feasible and applicable in China. This paper firstly discussed connotation and development of the marine regional management in China and pointed that the marine regional management is integrated management of a certain marine region. Next,it summarized characteristics of the marine regional management at current stage,for example,land-based pollution of trans-geographic system and marine management under regional government cooperative mechanism. Finally,it came up with recommendations including combining theory and practice of the marine regional management,and establishing marine regional management system as soon as possible,to realize benign interaction and sustainable development of marine economy and ecological environment.

  19. Institute of Tibetan Plateau Research

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ The Tibetan Plateau (Qinghai-Xizang Plateau)is a unique geological-geographical unit on Earth, an ideal region for studies into the formation and evolution of the lithosphere and the dynamic mechanism of the earth crust. The uplifting of the Plateau exerts profound influence upon the evolution and differentiation of the natural environment of the plateau itself, its adjacent regions and the Northern Hemisphere. As a unique natural geographical unit, the Plateau holds a special status in the whole globe due to its special natural environment and ecosystems, which is also in close relation to global environmental change.The significance of the Plateau research should be recognized not only in the fundamental research fields of geo-sciences and biology, but also in its application to resource exploitation, environmental protection and sustainable development of the Plateau region.

  20. Spatial and temporal variations of crop fertilization and soil fertility in the loess plateau in china from the 1970s to the 2000s.

    Science.gov (United States)

    Wang, Xiaoying; Tong, Yanan; Gao, Yimin; Gao, Pengcheng; Liu, Fen; Zhao, Zuoping; Pang, Yan

    2014-01-01

    Increased fertilizer input in agricultural systems during the last few decades has resulted in large yield increases, but also in environmental problems. We used data from published papers and a soil testing and fertilization project in Shaanxi province during the years 2005 to 2009 to analyze chemical fertilizer inputs and yields of wheat (Triticum aestivum L.) and maize (Zea mays L.) on the farmers' level, and soil fertility change from the 1970s to the 2000s in the Loess Plateau in China. The results showed that in different regions of the province, chemical fertilizer NPK inputs and yields of wheat and maize increased. With regard to soil nutrient balance, N and P gradually changed from deficit to surplus levels, while K deficiency became more severe. In addition, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium increased during the same period. The PFP of N, NP and NPK on wheat and maize all decreased from the 1970s to the 2000s as a whole. With the increase in N fertilizer inputs, both soil total nitrogen and alkali-hydrolysis nitrogen increased; P fertilizer increased soil available phosphorus and K fertilizer increased soil available potassium. At the same time, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium all had positive impacts on crop yields. In order to promote food safety and environmental protection, fertilizer requirements should be assessed at the farmers' level. In many cases, farmers should be encouraged to reduce nitrogen and phosphate fertilizer inputs significantly, but increase potassium fertilizer and organic manure on cereal crops as a whole.

  1. Spatial and temporal variations of crop fertilization and soil fertility in the loess plateau in china from the 1970s to the 2000s.

    Directory of Open Access Journals (Sweden)

    Xiaoying Wang

    Full Text Available Increased fertilizer input in agricultural systems during the last few decades has resulted in large yield increases, but also in environmental problems. We used data from published papers and a soil testing and fertilization project in Shaanxi province during the years 2005 to 2009 to analyze chemical fertilizer inputs and yields of wheat (Triticum aestivum L. and maize (Zea mays L. on the farmers' level, and soil fertility change from the 1970s to the 2000s in the Loess Plateau in China. The results showed that in different regions of the province, chemical fertilizer NPK inputs and yields of wheat and maize increased. With regard to soil nutrient balance, N and P gradually changed from deficit to surplus levels, while K deficiency became more severe. In addition, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium increased during the same period. The PFP of N, NP and NPK on wheat and maize all decreased from the 1970s to the 2000s as a whole. With the increase in N fertilizer inputs, both soil total nitrogen and alkali-hydrolysis nitrogen increased; P fertilizer increased soil available phosphorus and K fertilizer increased soil available potassium. At the same time, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium all had positive impacts on crop yields. In order to promote food safety and environmental protection, fertilizer requirements should be assessed at the farmers' level. In many cases, farmers should be encouraged to reduce nitrogen and phosphate fertilizer inputs significantly, but increase potassium fertilizer and organic manure on cereal crops as a whole.

  2. The effects of clouds and aerosols on net ecosystem CO2 exchange over semi-arid Loess Plateau of Northwest China

    Directory of Open Access Journals (Sweden)

    T. Wang

    2010-09-01

    Full Text Available The impacts of clouds and atmospheric aerosols on the terrestrial carbon cycle at semi-arid Loess Plateau in Northwest China are investigated, by using the observation data obtained at the SACOL (Semi-Arid Climate and Environment Observatory of Lanzhou University site. Daytime (solar elevation angles of larger than 50° net ecosystem exchange (NEE of CO2 obtained during the midgrowing season (July–August are analyzed with respect to variations in the diffuse radiation, cloud cover and aerosol optical depth (AOD. Results show a significant impact by clouds on the CO2 uptake by the grassland (with smaller LAI values located in a semi-arid region, quite different from areas covered by forests and crops. The light saturation levels in the canopy are low, with a value of about 434.8 W m−2. Thus, under overcast conditions of optically thick clouds, the CO2 uptake increases with increasing clearness index (the ratio of global solar radiation received at the Earth surface to the extraterrestrial irradiance at a plane parallel to the Earth surface, and a maximum CO2 uptake and light use efficiency of vegetation occur with the clearness index of about 0.37 and lower air temperature. Under other sky conditions, CO2 uptake decreases with cloudiness but light use efficiency is enhanced, due to increased diffuse fraction of PAR. Additionally, under cloudy conditions, changes in the NEE of CO2 also result from the interactions of many environmental factors, especially the air temperature. In contrast to its response to changes in solar radiation, the carbon uptake shows a slightly negative response to increased AOD. The reason for the difference in the response of the semi-arid grassland from that of the forest and crop lands may be due to the difference in the canopy's architectural structure.

  3. Integrating Data of ASTER and Landsat-8 OLI (AO for Hydrothermal Alteration Mineral Mapping in Duolong Porphyry Cu-Au Deposit, Tibetan Plateau, China

    Directory of Open Access Journals (Sweden)

    Tingbin Zhang

    2016-10-01

    Full Text Available One of the most important characteristics of porphyry copper deposits (PCDs is the type and distribution pattern of alteration zones which can be used for screening and recognizing these deposits. Hydrothermal alteration minerals with diagnostic spectral absorption properties in the visible and near-infrared (VNIR through the shortwave infrared (SWIR regions can be identified by multispectral and hyperspectral remote sensing data. Six Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER bands in SWIR have been shown to be effective in the mapping of Al-OH, Fe-OH, Mg-OH group minerals. The five VNIR bands of Landsat-8 (L8 Operational Land Imager (OLI are useful for discriminating ferric iron alteration minerals. In the absence of complete hyperspectral coverage area, an opportunity, however, exists to integrate ASTER and L8-OLI (AO to compensate each other’s shortcomings in covering area for mineral mapping. This study examines the potential of AO data in mineral mapping in an arid area of the Duolong porphyry Cu-Au deposit(Tibetan Plateau in China by using spectral analysis techniques. Results show the following conclusions: (1 Combination of ASTER and L8-OLI data (AO has more mineral information content than either alone; (2 The Duolong PCD alteration zones of phyllic, argillic and propylitic zones are mapped using ASTER SWIR bands and the iron-bearing mineral information is best mapped using AO VNIR bands; (3 The multispectral integration data of AO can provide a compensatory data of ASTER VNIR bands for iron-bearing mineral mapping in the arid and semi-arid areas.

  4. DEM and GIS analysis of the geomorphic indices to evaluate recent uplift of the northeast margin of the Tibetan Plateau, China

    Science.gov (United States)

    Gao, M.; Xu, X.; Zeilinger, G.; Wang, Q.; Hao, M.

    2011-12-01

    Geomorphic indices are indicators capable of detecting landform responses to deformation processes and therefore have been broadly used to investigate the tectonic geomorphology. The northeast margin of the Tibetan Plateau is a tectonic active region consists of series of arc structures with its bounded intermountain basins. It is located in the transitional zone between the Tibetan Plateau and the Loess Plateau. However, the widely covered loess made the fault traces hard to be detected. The analysis of the geomorphic properties of landscape could possibly reflect recent tectonic activities of the whole region. Thus, we applied geomorphic indices including hypsometry integral and the Stream Length-gradient to reveal the effects of neotectonics in the northeast margin of the Tibetan Plateau. By using the ASTER Global Digital Elevation Model, 197 drainage basins and 105 tributaries of the Yellow River have been analyzed. Together with the levelling data and the incision rates derived from the terraces dating, the long-term geologic/geomorphic rates and the short-term surface uplift rates are compared. Our results show the levelling data and the river incision rates have similar uplift pattern with the geomorphic indices. The high geomorphic values are corresponding with the hanging-wall of the active reverse faults and the certain segments of the active strike-slip faults. These uplifted segments may be the outcomes of the local stress concentration. The Maxianshan fault is identified to be a rapid uplift area. The SW-NE compression seems to be adjusted more by the thrust rather than strike-slip due to limited space for this fault propagating to the NW. The geomorphic indices appear to be effective to detect neotectonic activities in the loess-covered area. It helps to understand the differential uplift on a region such as the northeast margin of the Tibetan Plateau. The comparison between the geomorphic indices with levelling data could be a useful approach to

  5. Amplitude of climatic changes in Qinghai-Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    On the basis of ice core and meteorological data from the Qinghai-Tibetan (Q-T) Plateau, this article focuses on the discussion of the problems related to the sensitivity of temporal and spatial changes of the climate in high-altitude regions, particularly in the Q-T Plateau. The features of abrupt climatic changes of the past 100 ka, 2 000 a and recent years indicate that the amplitude of these changes in the Q-T Plateau was obviously larger than that in low-altitude regions. The scope of temperature change above 6 000 m in the Q-T Plateau between glacial and interglacial stages could reach over 10℃, but only about 4℃ in low-elevation regions close to sea level. During the last 2 000 a, the amplitude of temperature changes at Guliya (over 6 000 m a.s.l.) in the Q-T Plateau reached 7℃, in comparison with 2℃ in eastern China at low altitude. In the present age, apparent differences of climatic warming have been observed in the Q-T Plateau, indicating that the warming in high-elevation regions is much higher than that in low-elevation regions. The temperature in over 3 500 m regions of the Q-T Plateau have been increasing at a rate of 0.25×10-1/a in recent 30 years, but almost no change has taken place in the regions below 500 m. Thus, we concluded that high-altitude regions are more sensitive to climatic changes than the low-altitude regions.

  6. A China-Japan Cooperative JICA Atmospheric Observing Network over the Tibetan Plateau (JICA/Tibet Project): An Overviews

    National Research Council Canada - National Science Library

    ZHANG, Renhe; KOIKE, Toshio; XU, Xiangde; MA, Yaoming; YANG, Kun

    2012-01-01

    ... constructed an integrated atmospheric observing system, especially for the water vapor observation, across the Tibetan Plateau and its adjacent areas during the period of 2005-2009 under the JICA...

  7. ANALYSIS OF MESOSCALE CONVECTIVE SYSTEMS OVER TIBETAN PLATEAU IN SUMMER

    Institute of Scientific and Technical Information of China (English)

    GUO Zhong-yang; DAI Xiao-yan; WU Jian-ping; LIN Hui

    2006-01-01

    In this paper, Geostationary Meteorological Satellite (GMS) infrared black-body temperature (Tbb) data from June to August 1998 are used to automatically track the activity of Mesoscale Convective System (MCS) over the Tibetan Plateau in China. Consequently, the features of MCS, such as area, intensity, life cycle, activity region and shape, are obtained. High Resolution Limited Area Analysis and Forecasting System (HLAFS) values provided by China National Meteorological Center are used to study the relationships between the MCS trajectories and their environmental physical field values, based on the distribution and trajectories of MCSs over the Tibetan Plateau. Favorable environmental physical field charts of influencing MCS movement out of the Tibetan Plateau in different UTC (Universal Time Coordinate) are developed by using spatial data mining techniques at levels of 400hPa and 500hPa, respectively.

  8. A Communal Sign Post of Snow Leopards (Panthera uncia) and Other Species on the Tibetan Plateau, China

    OpenAIRE

    Juan Li; George B. Schaller; Thomas M. McCarthy; Dajun Wang; Zhala Jiagong; Ping Cai; Lamao Basang; Zhi Lu

    2013-01-01

    The snow leopard is a keystone species in mountain ecosystems of Central Asia and the Tibetan Plateau. However, little is known about the interactions between snow leopards and sympatric carnivores. Using infrared cameras, we found a rocky junction of two valleys in Sanjiangyuan area on the Tibetan Plateau where many mammals in this area passed and frequently marked and sniffed the site at the junction. We suggest that this site serves as a sign post to many species in this area, especially s...

  9. A GIS-based decision support system for regional eco-security assessment and its application on the Tibetan Plateau.

    Science.gov (United States)

    Xiaodan, Wang; Xianghao, Zhong; Pan, Gao

    2010-10-01

    Regional eco-security assessment is an intricate, challenging task. In previous studies, the integration of eco-environmental models and geographical information systems (GIS) usually takes two approaches: loose coupling and tight coupling. However, the present study used a full coupling approach to develop a GIS-based regional eco-security assessment decision support system (ESDSS). This was achieved by merging the pressure-state-response (PSR) model and the analytic hierarchy process (AHP) into ArcGIS 9 as a dynamic link library (DLL) using ArcObjects in ArcGIS and Visual Basic for Applications. Such an approach makes it easy to capitalize on the GIS visualization and spatial analysis functions, thereby significantly supporting the dynamic estimation of regional eco-security. A case study is presented for the Tibetan Plateau, known as the world's "third pole" after the Arctic and Antarctic. Results verified the usefulness and feasibility of the developed method. As a useful tool, the ESDSS can also help local managers to make scientifically-based and effective decisions about Tibetan eco-environmental protection and land use.

  10. Mapping seismic moment and b-value within the continental-collision orogenic-belt region of the Iranian Plateau

    Science.gov (United States)

    Mousavi, S. Mostafa

    2017-01-01

    In this paper, high-resolution map of the Gutenberg-Richter b-value and seismic moment-release are provided for the Iranian Plateau using the unified and homogeneous part of the seismicity record of the region (January 1995-July 2016). We use these parameters as stressmeters and qualitatively explore their correlations with the GPS velocity field, strain rate, faulting mechanism, attenuation, and structure of the region. Our goal is to reveal the correlations and anomalous patterns that can help to better understand the seismotectonics and the state of present-day crustal stress within the region. A negative correlation between b-value and seismic moment release as well as convergence rates is found. Correlation between geodetic measurements and seismic observations might indicate the existence of a strong mechanical coupling between the basement and the sediment cover across Zagros. High geodetic strain rates east of the Hormuz strait, southern central Alborz, and along the north Tabriz fault correspond to low b-value anomalies at these areas. A strong low b-value anomaly is observed at the major tectonic discontinuity between the Zagros continental collision and the oceanic Makran subduction.

  11. Regional technical innovation suitability and economic growth in China

    NARCIS (Netherlands)

    Zhou, Qing; Zhu, Dan; Ren, Liqin

    2012-01-01

    This paper aims to use quantitative method to analyse the suitability of regional technical innovation and further compare its influence to regional economic growth in China. Based on literature review, the authors develop an evaluation index system containing four aspects (namely, innovators, innov

  12. Regional technical innovation suitability and economic growth in China

    NARCIS (Netherlands)

    Zhou, Qing; Zhu, Dan; Brouwers-Ren, Liqin

    2012-01-01

    This paper aims to use quantitative method to analyse the suitability of regional technical innovation and further compare its influence to regional economic growth in China. Based on literature review, the authors develop an evaluation index system containing four aspects (namely, innovators,

  13. Developments in conservation tillage in rainfed regions of North China

    NARCIS (Netherlands)

    Wang, X.B.; Cai, D.X.; Hoogmoed, W.B.; Oenema, O.; Perdok, U.D.

    2007-01-01

    Dryland regions in northern China account for over 50% of the nation's total area, where farming development is constrained by adverse weather, topography and water resource conditions, low fertility soils, and poor soil management. Conservation tillage research and application in dryland regions of

  14. Alpine grassland soil organic carbon stock and its uncertainty in the three rivers source region of the Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Xiaofeng Chang

    Full Text Available Alpine grassland of the Tibetan Plateau is an important component of global soil organic carbon (SOC stocks, but insufficient field observations and large spatial heterogeneity leads to great uncertainty in their estimation. In the Three Rivers Source Region (TRSR, alpine grasslands account for more than 75% of the total area. However, the regional carbon (C stock estimate and their uncertainty have seldom been tested. Here we quantified the regional SOC stock and its uncertainty using 298 soil profiles surveyed from 35 sites across the TRSR during 2006-2008. We showed that the upper soil (0-30 cm depth in alpine grasslands of the TRSR stores 2.03 Pg C, with a 95% confidence interval ranging from 1.25 to 2.81 Pg C. Alpine meadow soils comprised 73% (i.e. 1.48 Pg C of the regional SOC estimate, but had the greatest uncertainty at 51%. The statistical power to detect a deviation of 10% uncertainty in grassland C stock was less than 0.50. The required sample size to detect this deviation at a power of 90% was about 6-7 times more than the number of sample sites surveyed. Comparison of our observed SOC density with the corresponding values from the dataset of Yang et al. indicates that these two datasets are comparable. The combined dataset did not reduce the uncertainty in the estimate of the regional grassland soil C stock. This result could be mainly explained by the underrepresentation of sampling sites in large areas with poor accessibility. Further research to improve the regional SOC stock estimate should optimize sampling strategy by considering the number of samples and their spatial distribution.

  15. Eco-environmental degradation in the source region of the Yellow River, Northeast Qinghai-Xizang Plateau.

    Science.gov (United States)

    Feng, Jianmin; Wang, Tao; Xie, Changwei

    2006-11-01

    The Yellow River is the second longest river in China and the cradle of the Chinese civilization. The source region of the Yellow River is the most important water holding area for the Yellow River, about 49.2% of the whole runoff comes from this region. However, for the special location, it is a region with most fragile eco-environment in China as well. Eco-environmental degradation in the source region of the Yellow River has been a very serious ecological and socially economic problem. According to census data, historical documents and climatic information, during the last half century, especially the last 30 years, great changes have taken place in the eco-environment of this region. Such changes are mainly manifested in the temporal-spatial changes of water environment, deglaciation, permafrost reduction, vegetation degeneracy and desertification extent, which led to land capacity decreasing and river disconnecting. At present, desertification of the region is showing an accelerating tendency. This paper analyzes the present status of eco-environment degradation in this region supported by GIS and RS, as well as field investigation and indoor analysis, based on knowledge, multi-source data is gathered and the classification is worked out, deals with their natural and anthropogenic causes, and points out that in the last half century the desertification and environmental degradation of this region are mainly attributed to human activities under the background of regional climate changes. To halt further degradation of the environment of this region, great efforts should be made to use land resources rationally, develop advantages animal agriculture and protect the natural grassland.

  16. Terrestrial mollusk evidence for the origin and sedimentary environment of the Late Tertiary Red Clay Formation in the Loess Plateau, China

    Institute of Scientific and Technical Information of China (English)

    PEI Yunpeng; WU Naiqin; LI Fengjiang

    2004-01-01

    The origin and sedimentary environment of the Late Tertiary (Neogene) Red Clay Formation in northern China had long been controversial. A new mollusk record from the Xifeng red clay (red-earth) sequence in the central Loess Plateau provides the biological evidence for addressing questions of its origin and environmental implication. The study of composition and preservation condition of seventy mollusk fossil assemblages reveals the initial ecological condition of the red clay formation, avoiding the effect of post-deposited alteration. The result shows that all of identifiable mollusk species are composed of terrestrial taxa, most of them are the common species found in the overlying Quaternary loess-paleosol sequence. Most of fossil individuals preserved in the red clay strata are in living conditions based on the investigation of fieldwork, indicating the original population. Thus, the mollusk fossil assemblages can be used as an indicator of primary environment of the red clay formation. The mollusk record from the Xifeng red clay sequence supports the view that the red clay is an aeolian origin, similar to the overlying Quaternary loess deposits. Our data also reveal the history of environmental changes at Xifeng from 6.2-2.4 Ma, which is coupled in phase with the formation and development of the Arctic ice sheets and the process of the Tibetan Plateau uplift. Both may be the major cause and forcing mechanisms of the late Tertiary environmental changes in the Loess Plateau.

  17. Natural conditions and cropping regionalization of rice area in China

    Institute of Scientific and Technical Information of China (English)

    WUXianzhang

    1994-01-01

    The formation of rice distribution is based on certain natural ecological conditions and social economic environments. In China, rice cropping is distributed in a vast area extending across 5 temperature belts, the northernmost of rice growing area in the world being in China. Distribution of rice cropping is characterized by a gradual decrease from south to north, from large and concentrated regions in Southeast to small and separated areasin Northwest.

  18. The Dynamic Plateau Monsoon Index and Its Association with General Circulation Anomalies

    Institute of Scientific and Technical Information of China (English)

    XUN Xueyi; HU Zeyong; MA Yaoming

    2012-01-01

    Based on monthly ECMWF reanalysis-Interim (ERA-Interim) reanalysis data,along with monthly precipitation and temperature data,the Dynamic Plateau Monsoon Index (DPMI) is defined.The results of a contrast analysis of the DPMI versus the Traditional Plateau Monsoon Index (TPMI) are described.The response of general circulation to northern Qinghai-Xizang Plateau summer monsoon anomalies and the correlation of the DPMI with general circulation anomalies are investigated.The results show that,the DPMI reflected meteorological elements better and depicted climate variation more accurately than the TPMI.In years when the plateau summer monsoon is strong,the low over the plateau and the trough near the eastern coast of Asia are deeper and higher than normal over South China.This correlation corresponds to two anomalous cyclones over the plateau and the eastern coast of Asia and an anomalous anticyclone in South China.The plateau and its adjacent regions are affected by anomalous southwesterly winds that transport more moisture to South China and cause more precipitation.The lower reaches of the Yangtze River appear to receive more precipitation by means of the strong westerly water vapor flow transported from the "large triangle affecting the region".In years when the plateau summer monsoon is weak,these are opposite.The plateau monsoon is closely related to the intensity and position of the South Asian high,and the existence of a teleconnection pattern in the mid-upper levels suggests a possible linl~ge of the East Asian monsoon and the Indian monsoon to the plateau summer monsoon.

  19. Regional comprehensive assessment on environment-health of China

    Institute of Scientific and Technical Information of China (English)

    WANGWuyi; LIRibang; LIAOYongfeng; LIHairong; YANGLinsheng; TANJianan

    2004-01-01

    The aim of the study was to assess the environment-health development in different regions of China. 175 indicators, such as average life expectancy at birth, emission intensity of waste gas, GDP etc. were chosen to describe various aspects of the environment, health and development of China. Of all the indicators, life expectancy can sufficiently reflect health situation of population. Consequently,life expectancy was identified as key indicator, and 42 out of 175 indicators were selected for establishing the environment-health indicator framework with three grades of integrative indices to assess the development of environment-health of China. Based on the hierarchical relation between various grades of indices, the comprehensive environment-health index was calculated and contributed to classify the environment-health situation of 30 provinces, municipalities and autonomous regions in China which were divided into five grades by four predefined limits. Comprehensive assessment indicates that the environment-health situation of the eastern and coastal areas is superior to that of inland which is the western regions with underdeveloped economy and rigorous natural condition.Especially, the Qinghai-Tibet and Yunnan-Guizhou plateaus in southwestern China are most vulnerable in the environment and population health. These fit in with the pattern of national socio-economic development, which fully shows that socio-economic context plays a dominant role in the improvement of envirnment-health in China

  20. Regional Consortia for E-Resources: A Case Study of Deals in the South China Region

    Science.gov (United States)

    Chunrong, Luo; Jingfen, Wang; Zhinong, Zhou

    2010-01-01

    Purpose: The purpose of this paper is to analyse the current situation and the social and economic benefits from the consortia acquisitions of electronic resources by the China Academic Library and Information System (CALIS) South China Regional Centre and to recommend improvements for consortia acquisitions. Design/methodology/approach: Analyses…

  1. Effect of Rotational Tillage on Soil Aggregates, Organic Carbon and Nitrogen in the Loess Plateau Area of China

    Institute of Scientific and Technical Information of China (English)

    HOU Xian-Qing; LI Rong; JIA Zhi-Kuan; HAN Qing-Fang

    2013-01-01

    In rain-fed semi-arid agroecosystems,continuous conventional tillage can cause serious problems in soil quality and crop production,whereas rotational tillage (no-tillage and subsoiling) could decrease soil bulk density,and increase soil aggregates and organic carbon in the 0-40 cm soil layer.A 3-year field study was conducted to determine the effect of tillage practices on soil organic carbon (SOC),total nitrogen (TN),water-stable aggregate size distribution and aggregate C and N sequestration from 0 to 40 cm soil in semi-arid areas of southern Ningxia.Three tillage treatments were tested:no-tillage in year 1,subsoiling in year 2,and no-tillage in year 3 (NT-ST-NT); subsoiling in year 1,no-tillage in year 2,and subsoiling in year 3 (ST-NT-ST); and conventional tillage over years 1-3 (CT).Mean values of soil bulk density in 0-40 cm under NT-ST-NT and ST-NT-ST were significantly decreased by 3.3% and 6.5%,respectively,compared with CT,while soil total porosity was greatly improved.Rotational tillage increased SOC,TN,and water-stable aggregates in the 0-40 cm soil,with the greatest effect under ST-NT-ST.In 0-20 and 20-40 cm soils,the tillage effect was confined to the 2-0.25 mm size fraction of soil aggregates,and rotational tillage treatments obtained significantly higher SOC and TN contents than conventional tillage.No significant differences were detected in SOC and TN contents in the > 2 mm and < 0.25 mm aggregates among all treatments.In conclusion,rotational tillage practices could significantly increase SOC and TN levels,due to a fundamental change in soil structure,and maintain agroecosystem sustainability in the Loess Plateau area of China.

  2. Variations of deep soil moisture under different vegetation types and influencing factors in a watershed of the Loess Plateau, China

    Science.gov (United States)

    Fang, Xuening; Zhao, Wenwu; Wang, Lixin; Feng, Qiang; Ding, Jingyi; Liu, Yuanxin; Zhang, Xiao

    2016-08-01

    Soil moisture in deep soil layers is a relatively stable water resource for vegetation growth in the semi-arid Loess Plateau of China. Characterizing the variations in deep soil moisture and its influencing factors at a moderate watershed scale is important to ensure the sustainability of vegetation restoration efforts. In this study, we focus on analyzing the variations and factors that influence the deep soil moisture (DSM) in 80-500 cm soil layers based on a soil moisture survey of the Ansai watershed in Yan'an in Shanxi Province. Our results can be divided into four main findings. (1) At the watershed scale, higher variations in the DSM occurred at 120-140 and 480-500 cm in the vertical direction. At the comparable depths, the variation in the DSM under native vegetation was much lower than that in human-managed vegetation and introduced vegetation. (2) The DSM in native vegetation and human-managed vegetation was significantly higher than that in introduced vegetation, and different degrees of soil desiccation occurred under all the introduced vegetation types. Caragana korshinskii and black locust caused the most serious desiccation. (3) Taking the DSM conditions of native vegetation as a reference, the DSM in this watershed could be divided into three layers: (i) a rainfall transpiration layer (80-220 cm); (ii) a transition layer (220-400 cm); and (iii) a stable layer (400-500 cm). (4) The factors influencing DSM at the watershed scale varied with vegetation types. The main local controls of the DSM variations were the soil particle composition and mean annual rainfall; human agricultural management measures can alter the soil bulk density, which contributes to higher DSM in farmland and apple orchards. The plant growth conditions, planting density, and litter water holding capacity of introduced vegetation showed significant relationships with the DSM. The results of this study are of practical significance for vegetation restoration strategies, especially

  3. Response of Extreme Precipitation to Solar Activity and El Nino Events in Typical Regions of the Loess Plateau

    Directory of Open Access Journals (Sweden)

    H. J. Li

    2017-01-01

    Full Text Available Extreme climatic oscillation has been the subject of global attention. The purpose of this study is to explore the response of extreme precipitation to solar activity and El Nino events in typical regions of the Loess Plateau—a case study in the Yan’an area. The precipitation data was from nine weather stations in Yan’an and the sunspot number and the Southern Oscillation Index (SOI were from 1951 to 2015. The results show that maximum precipitation occurred mainly at the peak sunspot number or 2a near it and the sunspot number minimum and valley values were not significantly correlated. The results of Morlet wavelet showed that a 41-year period of precipitation was the most obvious within the 64-year scale. Similarly, sunspot number showed a 16-year periodic variability. Correlation analyses of the 16-year and 41-year scales demonstrated that the relationships between precipitation and sunspot number were close. In addition, extreme precipitation often occurred in the year following El Nino events. According to 10-year moving average curves, precipitation generally showed a downward trend when SOI was negative. The results indicate that solar activity and El Nino events had significant impacts on precipitation in typical regions of the Loess Plateau.

  4. The Regional Surface Heating Field over the Heterogeneous Landscape of the Tibetan Plateau Using MODIS and In-Situ Data

    Institute of Scientific and Technical Information of China (English)

    MA Yaoming; WANG Binbin; ZHONG Lei; MA Weiqiang

    2012-01-01

    In this study,a parameterization scheme based on Moderate Resolution Imaging Spectroradiometer (MODIS) data and in-situ data was tested for deriving the regional surface heating field over a heterogeneous landscape.As a case study,the methodology was applied to the whole Tibetan Plateau (TP) area.Four images of MODIS data (i.e.,30 January 2007,15 April 2007,1 August 2007,and 25 October 2007) were used in this study for comparison among winter,spring,summer,and autumn.The results were validated using the observations measured at the stations of the Tibetan Observation and Research Platform (TORP).The results show the following:(1) The derived surface heating field for the TP area was in good accord with the land-surface status,showing a wide range of values due to the strong contrast of surface features in the area.(2) The derived surface heating field for the TP was very close to the field measurements (observations).The APD (absolute percent difference) between the derived results and the field observations was <10%.(3) The mean surface heating field over the TP increased from January to April to August,and decreased in October.Therefore,the reasonable regional distribution of the surface heating field over a heterogeneous landscape can be obtained using this methodology.The limitations and further improvement of this method are also discussed.

  5. Soil temperature and moisture sensitivities of soil C02 efflux before and after tillage in a wheat field of Loess Plateau, China

    Institute of Scientific and Technical Information of China (English)

    Hongxing Zhang; Xiaoke Wang; Zongwei Feng; Junzhu Pang; Fei Lu; Zhiyun Ouyang; Hua Zheng; Wenzhao Liu; Dafeng Hui

    2011-01-01

    As a conventional farming practice, tillage has lasted for thousands of years in Loess Plateau, China.Although recent studies show that tillage is a prominent culprit to soil carbon loss in croplands, few studies have investigated the influences of tillage on the responses of soil CO2 effiux (SCE) to soil temperature and moisture.Using a multi-channel automated CO2 effiux chamber system, we measured SCE in situ continuously before and after the conventional tillage in a rain fed wheat field of Loess Plateau, China.The changes in soil temperature and moisture sensitivities of SCE, denoted by the Q10 value and linear regression slope respectively, were compared in the same range of soil temperature and moisture before and after the tillage.The results showed that, after the tillage, SCE increased by 1.2-2.2 times; the soil temperature sensitivity increased by 36.1%-37.5%; and the soil moisture sensitivity increased by 140%-166%.Thus, the tiUage-induced increase in SCE might partially be attributed to the increases in temperature and moisture sensitivity of SCE.

  6. Soil temperature and moisture sensitivities of soil CO2 efflux before and after tillage in a wheat field of Loess Plateau, China.

    Science.gov (United States)

    Zhang, Hongxing; Wang, Xiaoke; Feng, Zongwei; Pang, Junzhu; Lu, Fei; Ouyang, Zhiyun; Zheng, Hua; Liu, Wenzhao; Hui, Dafeng

    2011-01-01

    As a conventional farming practice, tillage has lasted for thousands of years in Loess Plateau, China. Although recent studies show that tillage is a prominent culprit to soil carbon loss in croplands, few studies have investigated the influences of tillage on the responses of soil CO2 efflux (SCE) to soil temperature and moisture. Using a multi-channel automated CO2 efflux chamber system, we measured SCE in situ continuously before and after the conventional tillage in a rain fed wheat field of Loess Plateau, China. The changes in soil temperature and moisture sensitivities of SCE, denoted by the Q10 value and linear regression slope respectively, were compared in the same range of soil temperature and moisture before and after the tillage. The results showed that, after the tillage, SCE increased by 1.2-2.2 times; the soil temperature sensitivity increased by 36.1%-37.5%; and the soil moisture sensitivity increased by 140%-166%. Thus, the tillage-induced increase in SCE might partially be attributed to the increases in temperature and moisture sensitivity of SCE.

  7. [Effects of mulching patterns on soil water, broomcorn millet growth, photosynthetic charac- teristics and yield in the dryland of Loess Plateau in China].

    Science.gov (United States)

    Su, Wang; Zhang, Yan-Ping; Qu, Yang; Li, Cui; Miao, Jia-Yuan; Gao, Xiao-Li; Liu, Jian-Hua; Feng, Bai-Li

    2014-11-01

    The objective of this study was to explore the effects of mulching patterns on soil water, growth, photosynthetic characteristics, grain yield and water use efficiency (WUE) of broomcorn millet in the dryland of Loess Plateau in China. In a three-year field experiment from 2011 to 2013, we compared four different mulching patterns with traditional plat planting (no mulching) as the control (CK). The mulching patterns included W ridge covered with common plastic film + intredune covered with straw (SG), common ridge covered with common plastic film + intredune covered with straw (LM), double ridges covered with common plastic film + intredune covered with straw (QM), and the traditional plat planting covered with straw (JG). The results showed that the soil water storage in 0-100 cm layer was significantly higher in all mulching patterns than in CK, particularly in SG then followed by LM, QM and JG, and the differences among the mulching patterns reached a significant level at the different growth stages of broomcorn millet. Among all mulching patterns, SG had the greatest effect on the growth and photosynthesis of broomcorn millet, respectively increasing the yield and WUE by 55.9% and 64.9% over CK, and the differences among the mulching patterns also reached a significant level. Therefore, SG was recommended as an efficient planting pattern for broomcorn millet production in the dryland of Loess Plateau in China.

  8. Performance of soil particle-size distribution models for describing deposited soils adjacent to constructed dams in the China Loess Plateau

    Science.gov (United States)

    Zhao, Pei; Shao, Ming-an; Horton, Robert

    2011-02-01

    Soil particle-size distributions (PSD) have been used to estimate soil hydraulic properties. Various parametric PSD models have been proposed to describe the soil PSD from sparse experimental data. It is important to determine which PSD model best represents specific soils. Fourteen PSD models were examined in order to determine the best model for representing the deposited soils adjacent to dams in the China Loess Plateau; these were: Skaggs (S-1, S-2, and S-3), fractal (FR), Jaky (J), Lima and Silva (LS), Morgan (M), Gompertz (G), logarithm (L), exponential (E), log-exponential (LE), Weibull (W), van Genuchten type (VG) as well as Fredlund (F) models. Four-hundred and eighty samples were obtained from soils deposited in the Liudaogou catchment. The coefficient of determination (R 2), the Akaike's information criterion (AIC), and the modified AIC (mAIC) were used. Based upon R 2 and AIC, the three- and four-parameter models were both good at describing the PSDs of deposited soils, and the LE, FR, and E models were the poorest. However, the mAIC in conjunction with R 2 and AIC results indicated that the W model was optimum for describing PSD of the deposited soils for emphasizing the effect of parameter number. This analysis was also helpful for finding out which model is the best one. Our results are applicable to the China Loess Plateau.

  9. THE CHARACTERISTICS AND MAIN PROBLEMS OF MINORITY REGIONS IN CHINA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    China is a country that has a large number of minorities, who live in specific regions which are mainly located in central and west China. These regions are abundant in natural resources, which are potential advantages and also an important basis for economic development in these regions. They are of general importance for China in strategic and ecological terms. They will not only affect the environment for survival of the minority regions but also affect the sustain able development of the eastern and central parts of China and even the survival and development of the Chinese nation as a wbole. Minorities live in relatively compact communities, among the 55 minorities, 35 of them were highly compact minorities, with a compact level of more than 90%. Here the development in infrastructure as well as social and econonic development (e. g. export-oriented economy) has been and is still slow, regional poverty are most concentrated. The economic structures in minority areas are still in the low stage, which have resulted in underdevelopment in these regions.

  10. Characteristics of unilateral tibial plateau fractures among adult patients hospitalized at an orthopaedic trauma centre in China

    Science.gov (United States)

    Liu, Yong; Liao, Zhengwen; Shang, Lei; Huang, Wenhua; Zhang, Dawei; Pei, Guoxian

    2017-01-01

    The aim of this study was to investigate the characteristics of unilateral tibial plateau fractures among hospitalized adult patients in Xijing Hospital, to evaluate the accuracy of Schatzker classification system and AO/OTA classification system to tibial plateau fractures. We retrospectively analysed clinical data on 274 patients admitted to Xijing Hospital between September 2006 and August 2015. The patients’ demographic characteristics, admission periods and seasons, external causes and fracture types were recorded and summarized. Then the characteristics of tibial plateau fractures and the accuracy rate of these two classification systems were analysed. Schatzker type II fractures and AO/OTA type 41-B3 fractures were the most common types. The external causes differed between genders, types of employment, urban-rural residents and both two systems. In addition, some fractures were difficult to classify using Schatzker or AO/OTA classification system. Rural male physical labourers aged between 30–59 years-old were most likely to suffer from unilateral tibial plateau fractures, due to traffic accidents, falls and indoor activity injuries, or falls from height. We should pay more attention to the related people and professions, which contributed to the high occurrence of tibial plateau fractures. Besides that, further improvements are required for both Schatzker and AO/OTA classification systems. PMID:28074894

  11. Distribution characteristics and influencing factors of soil organic carbon in alpine ecosystems on the Tibetan Plateau transect, China

    Institute of Scientific and Technical Information of China (English)

    Yuqiang TIAN; Hua OUYANG; Minghua SONG; Haishan NIU; Qiwu HU

    2008-01-01

    The undisturbed regions along the Qinghai-Tibet Highway crossing the natural zones of montane desert, alpine meadow-steppe, and montane shrub-conifer-ous forest were chosen as the study areas. Soil samples were collected at 23 sites and the relations between the influ-encing factors and distribution of soil organic carbon (SOC) content were studied. The results indicated that the order of SOC content for the whole soil profile with differ-ent vegetations and in the horizontal direction was shown as below: forest > shrub > meadow > steppe > desert. All the SOC contents of the top 10 cm soil layers of forest, shrub and meadow vegetations, as well as that of the top 20 cm soil layers in steppe, in the vertical direction, were higher than those of corresponding lower soil layers. However, the SOC content in the desert soil was in accord-ance. The grey correlative analysis between the climatic factors and SOC content in the top soil show that precip-itation was the dominant climatic factor affecting the dis-tribution of SOC in the Tibetan Plateau transect. The influence of precipitation on the horizontal distribution of SOC decreased with the increase of precipitation in the horizontal direction. The vertical distribution of SOC along the soil profile was greatly affected by precipitation or the soil clay content in top soil layers, and was clearly influ-enced by soil silt content or sand content in lower soil layers, as well. The influences of both soil bulk density and soil pH on the vertical distribution of SOC along the soil profile gradually declined. The plant biomass was the most import-ant biotic factors affecting the distribution of the SOC.

  12. Impact of soil moisture and winter wheat height from the Loess Plateau in Northwest China on surface spectral albedo

    Science.gov (United States)

    Li, Zhenchao; Yang, Jiaxi; Gao, Xiaoqing; Zheng, Zhiyuan; Yu, Ye; Hou, Xuhong; Wei, Zhigang

    2016-12-01

    The understanding of surface spectral radiation and reflected radiation characteristics of different surfaces in different climate zones aids in the interpretation of regional surface energy transfers and the development of land surface models. This study analysed surface spectral radiation variations and corresponding surface albedo characteristics at different wavelengths as well as the relationship between 5-cm soil moisture and surface albedo on typical sunny days during the winter wheat growth period. The analysis was conducted using observational Loess Plateau winter wheat data from 2015. The results show that the ratio of atmospheric downward radiation to global radiation on typical sunny days is highest for near-infrared wavelengths, followed by visible wavelengths and ultraviolet wavelengths, with values of 57.3, 38.7 and 4.0%, respectively. The ratio of reflected spectral radiation to global radiation varies based on land surface type. The visible radiation reflected by vegetated surfaces is far less than that reflected by bare ground, with surface albedos of 0.045 and 0.27, respectively. Thus, vegetated surfaces absorb more visible radiation than bare ground. The atmospheric downward spectral radiation to global radiation diurnal variation ratios vary for near-infrared wavelengths versus visible and ultraviolet wavelengths on typical sunny days. The near-infrared wavelengths ratio is higher in the morning and evening and lower at noon. The visible and ultraviolet wavelengths ratios are lower in the morning and evening and higher at noon. Visible and ultraviolet wavelength surface albedo is affected by 5-cm soil moisture, demonstrating a significant negative correlation. Excluding near-infrared wavelengths, correlations between surface albedo and 5-cm soil moisture pass the 99% confidence test at each wavelength. The correlation with 5-cm soil moisture is more significant at shorter wavelengths. However, this study obtained surface spectral radiation

  13. Analysis of baseflow index based hydrological model in Upper Wei River basin on the Loess Plateau in China

    Science.gov (United States)

    Liu, D.; Chang, J.; Tian, F.; Huang, Q.; Meng, X.

    2015-05-01

    The baseflow is the drainage from the groundwater and soil water to the streamflow. As one important source of the streamflow, the baseflow could be the main source of the streamflow in the dry season. The Wei River, located in the semi-arid region of the Loess Plateau which is overlain by deep and loose soil, is the largest tributary of the Yellow River. According to former research, most of the streamflow in the dry season in the headwater of the Yellow River is baseflow. For the whole Yellow River basin, the baseflow is an important component of the streamflow, and accounts for about 44% of the annual runoff. Physically-based distributed hydrological models can simulate the runoff components separately, and are important tools to analyse the runoff components. Given the importance of the baseflow in the dry season for drought relief to support the ecological water requirement and irrigation, especially in the Wei River, the baseflow is analysed in this study. To investigate the baseflow in the Upper Wei River basin, a semi-distributed hydrological model based on a Representative Elementary Watershed approach (THREW) is employed to investigate the runoff generation process. To compare the results, an automatic baseflow separation method proposed by Arnold is used to separate the baseflow from the daily streamflow at Beidao hydrological station in Upper Wei River basin from 2001 to 2004. Based on the hydrological modelling and the Arnold separation method, the average annual baseflow index, i.e. the ratio of baseflow to the total runoff, is estimated as in the range of 0.30-0.36. The average intra-annual monthly baseflow index represents the seasonality of the baseflow due to the seasonality of the precipitation and evapotranspiration, and is also analysed.

  14. Effect of wide variation of the Waxy gene on starch properties in hull-less barley from Qinghai-Tibet plateau in China.

    Science.gov (United States)

    Li, Qiao; Pan, Zhifen; Deng, Guangbing; Long, Hai; Li, Zhongyi; Deng, Xiaoqing; Liang, JunJun; Tang, Yawei; Zeng, Xingquan; Tashi, Nyima; Yu, Maoqun

    2014-11-26

    Granule-bound starch synthase I (GBSS I) plays an important role in the synthesis of amylose and in the determination of starch properties in barley grains. Genomic DNAs for the Waxy gene encoding GBSS I protein were sequenced from 34 barley accessions or lines from Qinghai-Tibet plateau in China, to identify Waxy gene nucleotide variations and study the roles of polymorphic sites of the Waxy gene on expression levels of Waxy transcripts and GBSS I proteins and on resulting starch properties. A total of 116 DNA polymorphic sites were identified within the barley Waxy gene, which divided the studied accessions into 11 haplotypes. Among 33 nucleotide polymorphic sites in coding regions, 5 SNPs in three exons were found to play different roles on the expression level of the Waxy transcript and the GBSS I protein and on the amylose content and starch properties. One SNP G(3935)-to-T substitution in the 10th exon in the accession Z999 (HP II-2) caused a high expression level of the Waxy transcript and the GBSS I protein and the amylose free phenotype. The other SNP alteration was a C(2453)-to-T in the fifth exon in the accession Z1191 (HP I-5), which drastically reduced the expression level of the Waxy transcript and the GBSS I protein and, finally, produced the amylose free phenotype. Three SNPs in the seventh exon in the accession Z1337 (HP I-6) did not significantly change the level of Waxy transcript, the GBSS I protein, and starch properties, except obviously reducing the breakdown value of starch viscosity and extending the peak time. A total of 84 DNA polymorphic sites were found in the noncoding regions. A 403 bp deletion at 5'UTR in the accession Z1979 (HP I-3) had low transcript level, low GBSS I protein level, and low amylose content due to the deletion of cis-acting DNA regulatory elements. A 191 bp insertion and a 15 bp insertion in the first intron and second exons, respectively, may be closely related to a higher transcript level of the Waxy gene and

  15. Large and great earthquakes in the Shillong plateau-Assam valley area of Northeast India Region: Pop-up and transverse tectonics

    Science.gov (United States)

    Kayal, J. R.; Arefiev, S. S.; Baruah, Saurabh; Hazarika, D.; Gogoi, N.; Gautam, J. L.; Baruah, Santanu; Dorbath, C.; Tatevossian, R.

    2012-04-01

    The tectonic model of the Shillong plateau and Assam valley in the northeast India region, the source area for the 1897 great earthquake (Ms ~ 8.7) and for the four (1869, 1923, 1930 and 1943) large earthquakes (M. ≥ 7.0), is examined using the high precision data of a 20-station broadband seismic network. About 300 selected earthquakes M ≥ 3.0 recorded during 2001-2009 are analysed to study the seismicity and fault plane solutions. The dominating thrust/reverse faulting earthquakes in the western plateau may be explained by the proposed pop-up tectonics between two active boundary faults, the Oldham-Brahmaputra fault to the north and the Dapsi-Dauki thrust to the south, though the northern boundary fault is debated. The more intense normal and strike-slip faulting earthquakes in the eastern plateau (Mikir massif) and in the Assam valley, on the other hand, are well explained by transverse tectonics at the long and deep rooted Kopili fault that cuts across the Himalaya and caused the 2009 Bhutan earthquake (Mw 6.3). It is conjectured that the complex tectonics of the Shillong plateau and transverse tectonics at the Kopili fault make the region vulnerable for impending large earthquake(s).

  16. Upper mantle convection beneath northwest China and its adjacent region driven by density anomaly

    Institute of Scientific and Technical Information of China (English)

    XU Ping; FU Rong-shan; HUANG Jian-ping; ZHAXian-jie; DAI Zhi-yang

    2006-01-01

    We assume that the density anomalies, which are transformed from seismic tomography data, are corresponding to temperature distribution in a convective mantle. We take density anomalies as the driving force for mantle convec tion and solve the basic equation with given boundary conditions in a wave-number domain by using the FFT arithmetic. Using the physical model of upper mantle convection and the seismic tomography data supplied by XU et al, we calculated upper mantle convection beneath northwestern China and adjacent region. The flow patterns in the upper mantle show that there are upward and divergent flows in the basin regions, such as Tarim, Qaidam,Junggar and Kazakhstan, where the lithosphere is thin. There are downward and convergent flows in the mountain regions,such as Tianshan, Kunlun and Qilian, where the lithosphere is thick. In addition, because of the divergent flow under the Tarim Basin the upper mantle material in this region is driven southward to the north part of Tibetan Plateau and northward to Tianshan Mountain. Maybe, it is one of the reasons for the recent uplift of the Tianshan Mountain.

  17. Neogene fallout tuffs from the Yellowstone hotspot in the Columbia Plateau region, Oregon, Washington and Idaho, USA.

    Directory of Open Access Journals (Sweden)

    Barbara P Nash

    Full Text Available Sedimentary sequences in the Columbia Plateau region of the Pacific Northwest ranging in age from 16-4 Ma contain fallout tuffs whose origins lie in volcanic centers of the Yellowstone hotspot in northwestern Nevada, eastern Oregon and the Snake River Plain in Idaho. Silicic volcanism began in the region contemporaneously with early eruptions of the Columbia River Basalt Group (CRBG, and the abundance of widespread fallout tuffs provides the opportunity to establish a tephrostratigrahic framework for the region. Sedimentary basins with volcaniclastic deposits also contain diverse assemblages of fauna and flora that were preserved during the Mid-Miocene Climatic Optimum, including Sucker Creek, Mascall, Latah, Virgin Valley and Trout Creek. Correlation of ashfall units establish that the lower Bully Creek Formation in eastern Oregon is contemporaneous with the Virgin Valley Formation, the Sucker Creek Formation, Oregon and Idaho, Trout Creek Formation, Oregon, and the Latah Formation in the Clearwater Embayment in Washington and Idaho. In addition, it can be established that the Trout Creek flora are younger than the Mascall and Latah flora. A tentative correlation of a fallout tuff from the Clarkia fossil beds, Idaho, with a pumice bed in the Bully Creek Formation places the remarkably well preserved Clarkia flora assemblage between the Mascall and Trout Creek flora. Large-volume supereruptions that originated between 11.8 and 10.1 Ma from the Bruneau-Jarbidge and Twin Falls volcanic centers of the Yellowstone hotspot in the central Snake River Plain deposited voluminous fallout tuffs in the Ellensberg Formation which forms sedimentary interbeds in the CRBG. These occurrences extend the known distribution of these fallout tuffs 500 km to the northwest of their source in the Snake River Plain. Heretofore, the distal products of these large eruptions had only been recognized to the east of their sources in the High Plains of Nebraska and Kansas.

  18. Neogene fallout tuffs from the Yellowstone hotspot in the Columbia Plateau region, Oregon, Washington and Idaho, USA.

    Science.gov (United States)

    Nash, Barbara P; Perkins, Michael E

    2012-01-01

    Sedimentary sequences in the Columbia Plateau region of the Pacific Northwest ranging in age from 16-4 Ma contain fallout tuffs whose origins lie in volcanic centers of the Yellowstone hotspot in northwestern Nevada, eastern Oregon and the Snake River Plain in Idaho. Silicic volcanism began in the region contemporaneously with early eruptions of the Columbia River Basalt Group (CRBG), and the abundance of widespread fallout tuffs provides the opportunity to establish a tephrostratigrahic framework for the region. Sedimentary basins with volcaniclastic deposits also contain diverse assemblages of fauna and flora that were preserved during the Mid-Miocene Climatic Optimum, including Sucker Creek, Mascall, Latah, Virgin Valley and Trout Creek. Correlation of ashfall units establish that the lower Bully Creek Formation in eastern Oregon is contemporaneous with the Virgin Valley Formation, the Sucker Creek Formation, Oregon and Idaho, Trout Creek Formation, Oregon, and the Latah Formation in the Clearwater Embayment in Washington and Idaho. In addition, it can be established that the Trout Creek flora are younger than the Mascall and Latah flora. A tentative correlation of a fallout tuff from the Clarkia fossil beds, Idaho, with a pumice bed in the Bully Creek Formation places the remarkably well preserved Clarkia flora assemblage between the Mascall and Trout Creek flora. Large-volume supereruptions that originated between 11.8 and 10.1 Ma from the Bruneau-Jarbidge and Twin Falls volcanic centers of the Yellowstone hotspot in the central Snake River Plain deposited voluminous fallout tuffs in the Ellensberg Formation which forms sedimentary interbeds in the CRBG. These occurrences extend the known distribution of these fallout tuffs 500 km to the northwest of their source in the Snake River Plain. Heretofore, the distal products of these large eruptions had only been recognized to the east of their sources in the High Plains of Nebraska and Kansas.

  19. Diurnal Course of Gas Exchange and Water Use Efficiency of Platycladus orientalis in the Semiarid Region of the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    Tian Jinghui; He Kangning; Wang Baitian; Guo Jianghong; Zhang Weiqiang; Yin Jing

    2006-01-01

    The daily gas exchange,stomatal conductance,and water use efficiency of Platycladus orientalis in the test field of Fangshan county of Shanxi Province in the semiarid region of the Loess Plateau were measured with portable Li-6200 gas analysis system in natural conditions.The results showed that the diurnal course of net photosynthetic rate displayed a two-peak pattern,that of stomatal conductance displayed a hollow pattern,and that of transpiration rate displayed a signal-peak pattern.Water use efficiency culminated in the early morning.On the basis of two criteria of stomatal limitation of photosynthesis suggested by Farquhar and Sharkey,the predominant limiting factor of photosynthesis was the stomatal conductance of stomatal limitation in the morning (10:00-12:00).However,the midday depression of photosynthesis at noon (12:00-14:00) and the decrease in photosynthesis in the afternoon (16:00-18:00) were the results of nonstomatal limitation,such as low carboxylation capacity of the leaf mesophyll.

  20. Mapping Plant Functional Types over Broad Mountainous Regions: A Hierarchical Soft Time-Space Classification Applied to the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Danlu Cai

    2014-04-01

    Full Text Available Research on global climate change requires plant functional type (PFT products. Although several PFT mapping procedures for remote sensing imagery are being used, none of them appears to be specifically designed to map and evaluate PFTs over broad mountainous areas which are highly relevant regions to identify and analyze the response of natural ecosystems. We present a methodology for generating soft classifications of PFTs from remotely sensed time series that are based on a hierarchical strategy by integrating time varying integrated NDVI and phenological information with topography: (i Temporal variability: a Fourier transform of a vegetation index (MODIS NDVI, 2006 to 2010. (ii Spatial partitioning: a primary image segmentation based on a small number of thresholds applied to the Fourier amplitude. (iii Classification by a supervised soft classification step is based on a normalized distance metric constructed from a subset of Fourier coefficients and complimentary altitude data from a digital elevation model. Applicability and effectiveness is tested for the eastern Tibetan Plateau. A classification nomenclature is determined from temporally stable pixels in the MCD12Q1 time series. Overall accuracy statistics of the resulting classification reveal a gain of about 7% from 64.4% compared to 57.7% by the MODIS PFT products.

  1. Geological hazards in loess terrain, with particular reference to the loess regions of China

    Science.gov (United States)

    Derbyshire, Edward

    2001-06-01

    The considerable morphodynamic energy provided by the continuing tectonic evolution of Asia is expressed in high erosional potentials and very high rates of sediment production that make this continent unequalled as a terrestrial source of primary silt. Many of these environments are hazardous, threatening human occupation, health and livelihood, especially in regions of dense population such as the loess lands of north China. Dry loess can sustain nearly vertical slopes, being perennially under-saturated. However, when locally saturated, it disaggregates instantaneously. Such hydrocompaction is a key process in many slope failures, made worse by an underlying mountainous terrain of low-porosity rocks. Gully erosion of loess may yield very high sediment concentrations (>60% by weight). Characteristic vertical jointing in loess influences the hydrology. Enlarged joints develop into natural sub-surface piping systems, which on collapse, produce a "loess karst" terrain. Collapsible loess up to 20 m thick is common on the western Loess Plateau. Foundation collapse and cracked walls are common, many rapid events following periods of unusually heavy monsoonal rain. Slope failure is a major engineering problem in thick loess terrain, flow-slide and spread types being common. The results are often devastating in both urban and rural areas. An associated hazard is the damming of streams by landslides. The human population increases the landslide risk in China, notably through imprudent land-use practices including careless water management. A number of environmentally related endemic diseases arise from the geochemistry of loess and its groundwaters, including fluorosis, cretinism, Kaschin-Beck Disease, Keshan Disease and goitre. The Chinese desert margins also have a major atmospheric dust problem. The effect of such dust upon human health in these extensive regions, including many large cities, has yet to be evaluated, but pneumoconiosis is thought to affect several

  2. Climate warming and its impact on natural regional boundaries in China in the 1980s

    Institute of Scientific and Technical Information of China (English)

    SHA; Wanying; (沙万英); SHAO; Xuemei; (邵雪梅); HUANG; Mei; (黄玫)

    2002-01-01

    The global climate warming accelerated in the 1980s has become a focus in the world. Based on the month by month and year by year temperature data from 160 representative stations throughout the country during 1951-1999, this paper analyses annual and four seasons' temperature variations of China since the 1980s. It was found out that the non-equalibrium response with relative great regional and seasonal differences is represented in the country's climate warming. In regional changes a trend of "warm in the north and cold in the south" occurs whereas in seasonal changes, the characters of "warm in winter and cool in summer" present. Significant verification of the temperature variations conducted in terms of mathematical statistics reveals that a confidence level of over 95% has been basically reached in areas north of the Yangtze River. Meanwhile, according to data of diurnal mean temperature steadily passing through accumulated temperature ≥10℃ from 335 stations since 1951 or since the founding of the stations in the early 1950s to 1999, comparative analysis of the data of the last 19 years with that of the first 30 years was conducted and the accumulated temperature ≥10℃ and the variation range of the persistent number of days ≥10℃ were obtained. It was concluded that a general northward shift of central subtropics, north subtropics, warm temperate zone, mesothermal zone and frigid temperate zone of eastern China was observed. The northward shift of north subtropics and warm temperate zone was obvious but changes of south subtropics and marginal tropics were insignificant. In western China, in addition to southwestern Yunnan, the Qinghai-Tibet Plateau and western Inner Mongolia where the temperature zones of each either shifted northward or trended to move upward, not much changes were found in other areas or they shifted southward slightly and declined.

  3. High regional climate sensitivity over continental China constrained by glacial-recent changes in temperature and the hydrological cycle.

    Science.gov (United States)

    Eagle, Robert A; Risi, Camille; Mitchell, Jonathan L; Eiler, John M; Seibt, Ulrike; Neelin, J David; Li, Gaojun; Tripati, Aradhna K

    2013-05-28

    The East Asian monsoon is one of Earth's most significant climatic phenomena, and numerous paleoclimate archives have revealed that it exhibits variations on orbital and suborbital time scales. Quantitative constraints on the climate changes associated with these past variations are limited, yet are needed to constrain sensitivity of the region to changes in greenhouse gas levels. Here, we show central China is a region that experienced a much larger temperature change since the Last Glacial Maximum than typically simulated by climate models. We applied clumped isotope thermometry to carbonates from the central Chinese Loess Plateau to reconstruct temperature and water isotope shifts from the Last Glacial Maximum to present. We find a summertime temperature change of 6-7 °C that is reproduced by climate model simulations presented here. Proxy data reveal evidence for a shift to lighter isotopic composition of meteoric waters in glacial times, which is also captured by our model. Analysis of model outputs suggests that glacial cooling over continental China is significantly amplified by the influence of stationary waves, which, in turn, are enhanced by continental ice sheets. These results not only support high regional climate sensitivity in Central China but highlight the fundamental role of planetary-scale atmospheric dynamics in the sensitivity of regional climates to continental glaciation, changing greenhouse gas levels, and insolation.

  4. Regional ground deformation and its controlling measures in China

    Science.gov (United States)

    Zhou, Zhifang; Zhu, Haisheng; Huang, Yong

    2006-12-01

    With the development of construction of China Cities, there exist a lot of environmental geological problems involved in the geofracture, land subsidence, collapse, landslide, devolution, mudrock flow, floating sand, piping and soft ground deformation. Of big cities whose population is over one million in China, about 30 cities appears the land subsidence region. Other cities locate in the regions of collapse yellow earth or expand soil of strong swell-shrink charasteristic, soft ground and karst. In the paper, the cause and hazard of regionality ground deformation is summed up. The causes of regional land deformation caused by the natural geological effect and activities of human being are analyzed. According to the length of deformation course and endanger of society, economy and life, land deformation involves three types, that is, the delay, rapid and break land deformation. And the concrete countermeasure and method are provided.

  5. Tibial Plateau Fractures

    DEFF Research Database (Denmark)

    Elsøe, Rasmus

    This PhD thesis reported an incidence of tibial plateau fractures of 10.3/100,000/year in a complete Danish regional population. The results reported that patients treated for a lateral tibial plateau fracture with bone tamp reduction and percutaneous screw fixation achieved a satisfactory level...... with only the subgroup Sport significantly below the age matched reference population. The thesis reports a level of health related quality of life (Eq5d) and disability (KOOS) significantly below established reference populations for patients with bicondylar tibial plateau fracture treated with a ring...... fixator, both during treatment and at 19 months following injury. In general, the thesis demonstrates that the treatment of tibial plateau fractures are challenging and that some disabilities following these fractures must be expected. Moreover, the need for further research in the area, both with regard...

  6. Robust drying and wetting trends found in regions over China based on Köppen climate classifications

    Science.gov (United States)

    Chen, Tiexi; Zhang, Huixian; Chen, Xing; Hagan, Daniel Fiifi; Wang, Guojie; Gao, Zhiqiu; Shi, Tingting

    2017-04-01

    Controversial results in the drying and wetting trends were found with different indices and potential evapotranspiration calculations in previous studies. Here we make an attempt to find robust conclusions of drying and wetting trends over regions by coherent results of various independent indices by using China (1961-2012) as a study area. Precipitation, statistical, and physical drought indices, including the Standardized Precipitation Evapotranspiration Index (SPEI) and the Palmer Drought Severity Index (PDSI) and self-calibrating PDSI (sc_PDSI), with both the Penman-Monteith (PM) and Thornthwaite (TH) approaches in PDSI calculation are considered. In consequence, four PDSI variants of PDSI_pm, sc_PDSI_pm, PDSI_th, and sc_PDSI_th are involved. To illustrate regional characteristics, six climatic regions based on the Köppen climate classification are defined. At the national scale, precipitation and SPEI indicate wetting trends but all PDSI variants have drying trends. On the other hand, these six indices exhibit coherent results in five of these six regions. Increases in wetness occur in arid region and the Qinghai-Tibet Plateau. Drying trends were found in semiarid and cold and temperate semihumid regions. Only the humid region in southeastern China is seen to have increasing precipitation and SPEI and decreasing PDSI variants. From the perspective of climatic regions, the drying trends mainly occur in the transition regions between the humid and arid regions in China. The spatial pattern of changes in droughts could be categorized by climatic zones, and the changes at regional scale are robust based on these six indices.

  7. Regional Evolution Features and Coordinated Development Strategies for Northeast China

    Institute of Scientific and Technical Information of China (English)

    MEI Lin; XU Xiaopo; CHEN Mingxiu

    2006-01-01

    Northeast China, as the most important production base of agriculture, forestry, and livestock-breeding as well as the old industrial base in the whole country, has been playing a key role in the construction and development of China's economy. However, after the policy of reform and open-up was taken in China, the economic development speed and efficiency of this area have turned to be evidently lower than those of coastal area and the national average level as paper firstly reviews the spatial and temporal features of the regional evolution of this area so as to unveil the profound ploration into the status quo of this region and its forming causes by analyzing its economy gross, industrial structure,product structure, regional eco-categories, etc. At the end of the paper, the authors put forward the basic coordinated development strategies for Northeast China, namely we can revitalize this area by means of adjustment of economic structure, regional coordination, planning urban and rural areas as a whole, institutional innovation, etc.

  8. The Arctic - A New Region for China's Foreign Policy

    Directory of Open Access Journals (Sweden)

    V S Yagiya

    2015-12-01

    Full Text Available Article is devoted to foreign policy of China in the Arctic. Main attention is paid to strategic view of the China concerning the Arctic, to bilateral and multilateral cooperation on the Arctic issues, also to opinion of Russian experts about discussing of Russian-China economic partnership. It was shown interests of the People's Republic of China in the Arctic: use Arctic transport system from the Pacific Rim to Europe; possibility of access to the Arctic resources; seeks of partners for the realized of Arctic projects and programs. It was pointed six directions of China cooperation in the Arctic: a scientific researches, b natural minerals, oil and gas issues, c tourism, d routes of the Arctic navigation, e use of high technologies in development of regional economy, e cooperation in the cultural and educational spheres. Authors are summarized that at the initial stage of the international cooperation in the Arctic polar scientific researches become as the tool of “he soft power”, and in the long term - the Northern Sea Route of the Russian Federation is included in the Strategy of China Economic belt and the Maritime Silk Route in the XXI century.

  9. Forest Fires and Prevention Strategies in Northwestern Region of China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The paper described the natural conditions and forest types in Northwestern Region of China. Most forests in the region are distributed in subalpine areas. It is important to protect the existent forests in the region for maintaining ecological balance. According to the statistics results of 1991~2000, the paper analyzes the forest fires distribution and fire severity. Annually the numbers of forest fires range from 52 to 240. The incidence rate of forest fires in Northwestern Region is under 0.33 per t...

  10. Atmospheric processes of organic pollutants over a remote lake on the central Tibetan Plateau: implications for regional cycling

    Science.gov (United States)

    Ren, Jiao; Wang, Xiaoping; Wang, Chuanfei; Gong, Ping; Yao, Tandong

    2017-01-01

    Atmospheric processes (air-surface exchange, and atmospheric deposition and degradation) are crucial for understanding the global cycling and fate of organic pollutants (OPs). However, such assessments over the Tibetan Plateau (TP) remain uncertain. More than 50 % of Chinese lakes are located on the TP, which exerts a remarkable influence on the regional water, energy, and chemical cycling. In this study, air and water samples were simultaneously collected in Nam Co, a large lake on the TP, to test whether the lake is a secondary source or sink of OPs. Lower concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were observed in the atmosphere and lake water of Nam Co, while the levels of polycyclic aromatic hydrocarbons (PAHs) were relatively higher. Results of fugacity ratios and chiral signatures both suggest that the lake acted as the net sink of atmospheric hexachlorocyclohexanes (HCHs), following their long-range transport driven by the Indian monsoon. Different behaviours were observed in the PAHs, which primarily originated from local biomass burning. Acenaphthylene, acenaphthene, and fluorene showed volatilization from the lake to the atmosphere, while other PAHs were deposited into the lake due to the integrated deposition process (wet/dry and air-water gas deposition) and limited atmospheric degradation. As the dominant PAH compound, phenanthrene exhibited a seasonal reversal of air-water gas exchange, which was likely related to the melting of the lake ice in May. The annual input of HCHs from the air to the entire lake area (2015 km2) was estimated as 1.9 kg yr-1, while input estimated for ∑ 15PAHs can potentially reach up to 550 kg yr-1. This study highlights the significance of PAH deposition on the regional carbon cycling in the oligotrophic lakes of the TP.

  11. Sedimentary and crustal thicknesses and Poisson's ratios for the NE Tibetan Plateau and its adjacent regions based on dense seismic arrays

    Science.gov (United States)

    Wang, Weilai; Wu, Jianping; Fang, Lihua; Lai, Guijuan; Cai, Yan

    2017-03-01

    The sedimentary and crustal thicknesses and Poisson's ratios of the NE Tibetan Plateau and its adjacent regions are estimated by the h- κ stacking and CCP image of receiver functions from the data of 1,317 stations. The horizontal resolution of the obtained results is as high as 0.5° × 0.5°, which can be used for further high resolution model construction in the region. The crustal thicknesses from Airy's equilibrium are smaller than our results in the Sichuan Basin, Qilian tectonic belt, northern Alxa block and Qaidam Basin, which is consistent with the high densities in the mantle lithosphere and may indicate that the high-density lithosphere drags crust down overall. High Poisson's ratios and low velocity zones are found in the mid- and lower crust beneath eastern Qilian tectonic belt and the boundary areas of the Ordos block, indicating that partial melting may exist in these regions. Low Poisson's ratios and low-velocity anomalies are observed in the crust in the NE Tibetan Plateau, implying that the mafic lower crust is thinning or missing and that the mid- and lower crust does not exhibit melting or partial melting in the NE Tibetan Plateau, and weak flow layers are not likely to exist in this region.

  12. Assessing and regulating the impacts of climate change on water resources in the Heihe watershed on the Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Climate change can cause considerable changes in water resources and assessing the potential impacts can provide important information for regional sustainable development. The objectives were to evaluate the possible impacts of climate change during 2010-2039 on water resources (runoff, soil water content, and evapotranspiration) in the Heihe watershed on the Loess Plateau of China and to further explore adaptive measures to cope with the changes. Projections of four climate models (CCSR/NIES, CGCM2, CSIRO-Mk2, and HadCM3) under three emission scenarios (A2, B2, and GGa) were used to estimate future changes in precipitation, maximum and minimum temperature based on Change Factor method. The Soil and Water Assessment Tool (SWAT) was employed to simulate the hydrologic responses to climate changes. The CA-Markov model was used to develop land use scenarios. Compared with the present climate, the climate models predicted a -2.3% to 7.8% change in annual precipitation, 0.7 to 2.2°C rises in maximum temperature, and 1.2 to 2.8°C rises in minimum temperature. Without consideration of land use change, SWAT predicted a -19.8% to 37.0% change for runoff, -5.5% to 17.2% change for soil water content, and 0.1% to 5.9% increase for evapotranspiration during 2010–2039 under all climate scenarios. Though the change of hydrometeorolocial variables are complex, they would possibly increase with great probability, and the hydrological regime would be influenced such as a decrease in runoff in winter months. With land use changes, the projected land use of 2015 would increase soil water content by 4.0% and surface runoff by 5.7% while slightly decrease evapotranspiration by 0.6% compared with the 2000 land use. This result showed that adjustment of land use patterns was capable of regulating water resources and could be used to mitigate the adverse effects of climate change.

  13. Soil formation in high elevation and permafrost areas in the Qinghai Plateau (China Edafogénesis en zonas elevadas y con permafrost en el Plateau Qunghai (China Formação do solo em áreas de elevada altitude e em ambientes"permafrost" do planalto de Qinghai Plateau (China

    Directory of Open Access Journals (Sweden)

    Joselito Arocena

    2012-07-01

    Full Text Available

    Soil systems continuously gain and lose matter and energy even in areas where climate is too harsh to support the higher plants such as in high elevations and in permafrost environments. The purpose of this paper was to elucidate soil formation at 4 700 m asl in the Kunlun Mountains of the Qinghai (Tibet Plateau, China. We collected twenty-six samples from three pedons developed on carbonate-rich slate and quartzitic-sandstone materials. The samples were analyzed for routine physical, chemical and mineralogical properties. Our results indicate that soil-forming processes are barely taking place in the study site as shown by pH > 7.0 reflecting limited decarbonation, biological activity (< 1.0% total C and < 0.05% total N, podzolization (<1 g Fep+Alp kg-1 soil and lessivage. The relative amounts of mica and kaolinite show no apparent change with depth suggesting minimal transformation and translocation of phyllosilicates. The most noticeable mineral transformation resulted in micaceous “flakes” and feldspathic “fragments” possibly due to thermal stress. Calcite is also observed coating the slate fragments. The soils are classified as Cryosols in the World Reference Base system and Gelisols in the Soil Taxonomy with ochric epipedon as the only diagnostic horizon indicating recent development of soils due to cold and arid environment. The results of this study show that soil-forming processes in harsh environments are manifested in the mechanical breakdown of minerals such as mica and feldspars.

    Los sistemas edáficos ganan y pierden continuamente materia y energía incluso en zonas donde el clima es demasiado severo como para permitir el desarrollo de plantas superiores, como son las zonas de elevada altitud o los ambientes con permafrost. El objetivo de este trabajo es analizar la formación del suelo a una altitud de 4 700 m en las Monta

  14. Mapping the Energy Flow from Supply to End Use in three Geographic Regions of China

    OpenAIRE

    Mischke, Peggy; Xiong, Weiming

    2014-01-01

    China's past economic development policies resulted in different energy infrastructure patterns across China. There is a long tradition in analysing and discussing regional disparities of China's economy. For more than 20 years, regional differences in GDP, industrial outputs, household income and consumption were analysed across China's provincial units. Regional disparities in China's current energy flow are rarely visualised and quantified from a comprehensive, system-wide perspective that...

  15. Factors controlling regional grain yield in China over the last 20 years

    NARCIS (Netherlands)

    wang, Xiaobin; Cai, D.X.; Grant, C.; Hoogmoed, W.B.; Oenema, O.

    2015-01-01

    Food production is highly dependent on regional yields of crops. Regional differences in grain yields could be due to fertilizer management and climate variability. Here, we analyze trends of grain yields in North China, Northeast China, East China, and Central and Southwest China from 1992 to 2012,

  16. Factors controlling regional grain yield in China over the last 20 years

    NARCIS (Netherlands)

    wang, Xiaobin; Cai, D.X.; Grant, C.; Hoogmoed, W.B.; Oenema, O.

    2015-01-01

    Food production is highly dependent on regional yields of crops. Regional differences in grain yields could be due to fertilizer management and climate variability. Here, we analyze trends of grain yields in North China, Northeast China, East China, and Central and Southwest China from 1992 to 2012,

  17. Balancing regional industrial development: analysis on regional disparity of China's industrial emissions and policy implications

    DEFF Research Database (Denmark)

    Liang, Hanwei; Dong, Liang; Luo, Xiao

    2016-01-01

    Efficient industrial emissions mitigation strategy is critical for China's national action on climate change and sustainable development, considering its rapid industrialization. Regional disparity brings difficulties and uncertainties to policy implementation in China. Therefore, an investigation...... development, and highlight not only disparity, but also inequity exists. It is concluded that, there is a larger unequal distribution of GDP per unit of air pollutants and CO2 emission between eastern and western regions, reveals that less developed western and central regions suffer from the emission leakage...

  18. Spatio-temporal Difference of Economic Growth in the Loess Plateau Region over the Past 20 Years%近20年来黄土高原地区的经济增长时空分异特征

    Institute of Scientific and Technical Information of China (English)

    刘艳华; 徐勇; 刘毅

    2012-01-01

    经济不均衡增长是区域发展的一种常态.分析区域经济增长时空差异及成因,对于认识和加快落后地区的经济发展具有重要的意义.本研究在GIS技术的支持下,对黄土高原地区近20年来以县市为单元的经济增长时空分异特征进行了系统的分析.主要结论有:改革开放以来,黄土高原地区的GDP水平呈现出持续的快速增长态势.近20年来,陕北和内蒙古鄂尔多斯地区增长最为迅速;人均GDP的空间分布整体上呈现出“两高一低”的带状分布格局,且这种格局明显地受到极化增长的扰动和重塑;经济增长表现出显著的极化增长特征,且经济增长极的极化作用与增长极之间地位的调整是同时进行的;与常态化的城市产业集聚推动型经济相比,机遇性的资源开发拉动型经济对人均GDP的拉动速度更快,但可持续性较差.未来,黄土高原地区应走以中心城市带动为主,以能矿产资源开发拉动为辅,两者相互促进,共同带动整个区域经济更快、更好、更可持续地发展的道路.%Economic activities are always located unevenly in a region. Analyzing and detecting the spatio-temporal difference of economic factors, and finding out the underlying reasons would be very useful for undeveloped regions to recognize problems and then seek for a better way to deal with them. Under support of GIS, this essay analyzed the spatio-temporal characteristics of economy growth on the Loess Plat-eau Region over the past 20 years by using data of 284 counties' per capita GDP. And the results included: (1) The level of GDP of the Loess Plateau Region had been growing continuously and rapidly since the Reform and Opening of China. And the Western Development Strategy of China is the main reason for the rapid increase of proportion of GDP of the Loess Plateau Region in that of the whole China since 2000, while energy/resources exploring in Shanxi, Shaanxi and Inner Mongolia Region

  19. A METHOD TO ESTIMATE PALEOTEMPERATURE FROM ENVIRONMENTAL PROXIES IN LAKE SEDIMENTS——A STUDY ON ZOIGE BASIN IN EASTERN TIBETAN PLATEAU, CHINA

    Institute of Scientific and Technical Information of China (English)

    吴敬禄; A.Luecke; 夏崴岚; 李世杰; G.H.Schleser; 王苏民

    2001-01-01

    Seeking for an effective method to probe further the relation among Tibetan Plateau, climatic events, and natural environmental changes in the Zoige Basin, we proposed a physical model for the reconstruction of climate and environment and a preliminary application was conducted on the 45 m (about 200 ka BP ), upper part of Core RM (310 m long) drilled in the Zoige Basin (33°57'N, 102°21'E), on the eastern Tibetan Plateau. The results showed that: a) in the Zoige region, the maximum tem-perature in the period equivalent to Stage 7 in the deep-sea stable oxygen record was 2.7℃ higher than that at present; b) Stage 6 temperature was 4.3℃ lower than that at present; c) Stage 5 peak tempera-ture was 5.2℃ higher than that at present; d) Stage 4 average temperature should have been 2 - 3℃ lower than that at present; and e) Stage 3 temperature differences within the period were more than 4℃. It was found that during Stage 6 (140 - 160 ka BP) the environment in the Zoige Basin was extraordi-nary, representing a transition period from warm-dry and cold-wet to warm-wet and cold-dry environmental conditions due to the uplift that occurred on the Tibetan Plateau at this period.

  20. Livelihood Strategy Change and Land Use Change——Case of Danzam Village in Upper Dadu River Watershed, Tibetan Plateau of China

    Institute of Scientific and Technical Information of China (English)

    YAN Jianzhong; ZHANG Yili; ZHANG Liping; WU Yingying

    2009-01-01

    Land use change in rural China since the 1980s, induced by institution reforms, urbanization, industrializa-tion and population increase, has received more attention. However, case studies on how institution reforms affect farmers' livelihood strategies and drive land use change are scarce. By means of cropland plots investigations and in-terviews with farmers, this study examines livelihood strategy change and land use change in Danzam Village of Jinchuan County in the upper Dadu River watershed, eastern Tibetan Plateau, China. The results show that, during the collective system period, as surplus labor forces could not be transferred to the secondary and tertiary industries, they had to choose agricultural involution as their livelihood strategy, then the farmers had to produce more grains by land reclamation, increasing multiple cropping index, improving input of labor, fertilizer, pesticide and adopting advanced agricultural techniques. During the household responsibility system period, as labors being transferred to the secondary and tertiary industries, farmers chose livelihood diversification strategy. Therefore, labor input to grain planting was greatly reduced, which drove the transformation of grain to horticulture, vegetable or wasteland and decrease of multi-ple cropping index. This study provides a new insight into understanding linkages among institution reforms, liveli-hood strategy of smallholders and land use change in rural China.

  1. Characteristics of net ecosystem carbon dioxide exchange(NEE) from August to October of Alpine meadow on the Tibetan Plateau,China

    Institute of Scientific and Technical Information of China (English)

    XU Lingling; ZHANG Xianzhou; SHI Peili; YU Guirui; SUN Xiaomin

    2006-01-01

    The Alpine meadow is one of the vegetation types widely distributed on the Tibetan Plateau in China with an area of about 1.2 million square kilometers.The Damxung rangeland station,located in the hinterland of the Tibetan Plateau,is covered with an typical vegetation.The continuous carbon flux data (from August to middle October,2003) measured with the open-path eddy covariance system was used to analyze the diurnal variation pattern of net ecosystem carbon dioxide exchange (NEE) and its relationship with the environmental factors,such as photosynthetically active radiation (PAR),precipitation,and temperature.Results showed that NEE presented obvious diurnal variation pattern with single-peak of diurnal maximum carbon assimilation at 11:00-12:00 (local time) with an CO2.m-2-s-1.During the daytime,NEE fitted fairly well with PAR in a rectangular hyperbola function with the apparent the night-time,NEE showed a good exponential relation with the soil temperature at 5 cm depth.

  2. Runoff and Sediment Yield Variations in Response to Precipitation Changes: A Case Study of Xichuan Watershed in the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    Tianhong Li

    2015-10-01

    Full Text Available The impacts of climate change on hydrological cycles and water resource distribution is particularly concerned with environmentally vulnerable areas, such as the Loess Plateau, where precipitation scarcity leads to or intensifies serious water related problems including water resource shortages, land degradation, and serious soil erosion. Based on a geographical information system (GIS, and using gauged hydrological data from 2001 to 2010, digital land-use and soil maps from 2005, a Soil and Water Assessment Tool (SWAT model was applied to the Xichuan Watershed, a typical hilly-gullied area in the Loess Plateau, China. The relative error, coefficient of determination, and Nash-Sutcliffe coefficient were used to analyze the accuracy of runoffs and sediment yields simulated by the model. Runoff and sediment yield variations were analyzed under different precipitation scenarios. The increases in runoff and sediment with increased precipitation were greater than their decreases with reduced precipitation, and runoff was more sensitive to the variations of precipitation than was sediment yield. The coefficients of variation (CVs of the runoff and sediment yield increased with increasing precipitation, and the CV of the sediment yield was more sensitive to small rainfall. The annual runoff and sediment yield fluctuated greatly, and their variation ranges and CVs were large when precipitation increased by 20%. The results provide local decision makers with scientific references for water resource utilization and soil and water conservation.

  3. [Growth process and diameter structure of Pinus tabulaeformis forest for soil and water conservation in Loess Plateau Hilly regions].

    Science.gov (United States)

    Zhang, Guang-Can; Liu, Xia; Zhou, Ze-Fu; Zhang, Shu-Yong; Liu, Gang; Chen, Jian

    2007-04-01

    Through stem analysis of sample trees, the biomass, growth process, and diameter structure of two 21 years old Pinus tabulaeformis forests growing on the shady and sunny slopes in Loess Plateau hilly and gully regions were investigated. The results showed that there were distinct differences between these two forests in their tree height, diameter at breast height (DBH), and timber volume. The forest biomass, growth status, and diameter structure on shady slope were superior to those on sunny slope. The fast-growing period of tree height all appeared in the period of 9-13 years, and after 13 years, the annual increment of tree height was larger in shady slope forest than in sunny slope forest, with the increment in the 21st year being 0.26 and 0.1, respectively. The DBH growth of the two forests was declined greatly after 13 years, but the decrement was obviously less in shady slope forest than in sunny slope forest. After 17 years, the annual increment of DBH growth was larger in shady slope forest than in sunny slope forest, with the values being 0.46 cm x a(-1) and 0.27 cm x a(-1), respectively in the 21st year. Before 13 years, there was little difference in the increment of timber production between the two forests, but the increment after 13 years was larger in shady slope forest than in sunny slope forest, with the values of 0.0023 m3 and 0.0015 m3, respectively in the 21st year. The summit of DBH distribution curve was all partial to left, but the skewness of shady slope forest (SK = 0.75) was lower than that of sunny slope forest (SK = 1.03), and the kurtosis of shady slope forest (K = 1.05) was higher than that of sunny slope forest (K = 0.94), indicating that sunny slope forest had a larger stand density than shady slope forest.

  4. Prevalence and risk factors of undernutrition among schoolchildren in the Plateau Central and Centre-Ouest regions of Burkina Faso.

    Science.gov (United States)

    Erismann, Séverine; Knoblauch, Astrid M; Diagbouga, Serge; Odermatt, Peter; Gerold, Jana; Shrestha, Akina; Tarnagda, Grissoum; Savadogo, Boubacar; Schindler, Christian; Utzinger, Jürg; Cissé, Guéladio

    2017-01-19

    Multiple factors determine children's nutritional status, including energy and nutrient intake, recurrent infectious diseases, access (or lack thereof) to clean water and improved sanitation, and hygiene practices, among others. The "Vegetables go to School: improving nutrition through agricultural diversification" (VgtS) project implements an integrated school garden programme in five countries, including Burkina Faso. The aim of this study was to determine the prevalence of undernutrition and its risk factors among schoolchildren in Burkina Faso before the start of the project. In February 2015, a cross-sectional survey was carried out among 455 randomly selected children, aged 8-14 years, in eight schools in the Plateau Central and Centre-Ouest regions of Burkina Faso. Nutritional status was determined by anthropometric assessment. Helminth and intestinal protozoa infections were assessed using the Kato-Katz and a formalin-ether concentration method. A urine filtration technique was used to identify Schistosoma haematobium eggs. Prevalence of anaemia was determined by measuring haemoglobin levels in finger-prick blood samples. Questionnaires were administered to children to determine their knowledge of nutrition and health and their related attitudes and practices (KAP). Questionnaires were also administered to the children's caregivers to identify basic household socio-demographic and economic characteristics, and water, sanitation and hygiene (WASH) conditions. To determine the factors associated with schoolchildren's nutritional status, mixed logistic regression models were used. Differences and associations were considered statistically significant if P-values were below 0.05. Complete datasets were available for 385 children. The prevalence of undernutrition, stunting and thinness were 35.1%, 29.4% and 11.2%, respectively. The multivariable analysis revealed that undernutrition was associated with older age (i.e. 12-14 years compared to risk factors among

  5. Landcover Change, Land Surface Temperature, Surface Albedo and Topography in the Plateau Region of North-Central Nigeria

    Directory of Open Access Journals (Sweden)

    Shakirudeen Odunuga

    2015-04-01

    Full Text Available This study assessed the change in some environmental parameters in the Plateau region of North-Central Nigeria (Barakinladi, Jos, and Kafachan environs using the nexus of landcover change, land surface temperature, surface albedo, and topography. The study employed both remote sensing and statistical techniques for the period between 1986 and 2014 to analyze the dynamics between and within these environmental variables. In Barakinladi, the built up landcover change is highest (increasing from 39.53% to 47.59% between 1986 and 2014; LST ranges from 19.09 °C to 38.59 °C in 1986 and from 22.68 °C and 41.68 °C in 2014; and the albedo ranges between 0.014 and 0.154 in 1986 and 0.017 and 0.248 in 2014. In Jos, the built-up landcover occupied 34.26% in 1986 and 36.67% in 2014; LST values range between 20.83 °C and 41.33 °C in 1986 and between 21.61 °C and 42.64 °C in 2014; and the albedo ranges between 0.003 and 0.211 in 1986 and 0.15 and 0.237 in 2014. In Kafachan area, the built up landcover occupied 32.95% in 1986 and 39.01% in 2014. Urbanization and agricultural activities, including animal grazing, were responsible for the gradual loss in vegetation and increasing average LST and albedo. The results also revealed that changing landcover and topography have a relationship with surface albedo and land surface temperature, thereby impacting significantly on ecosystem services delivered by the natural system.

  6. Spatio-temporal variation of erosion-type non-point source pollution in a small watershed of hilly and gully region, Chinese Loess Plateau.

    Science.gov (United States)

    Wu, Lei; Liu, Xia; Ma, Xiao-Yi

    2016-06-01

    Loss of nitrogen and phosphorus in the hilly and gully region of Chinese Loess Plateau not only decreases the utilization rate of fertilizer but also is a potential threat to aquatic environments. In order to explore the process of erosion-type non-point source (NPS) pollution in Majiagou watershed of Loess Plateau, a distributed, dynamic, and integrated NPS pollution model was established to investigate impacts of returning farmland on erosion-type NPS pollution load from 1995 to 2012. Results indicate that (1) the integrated model proposed in this study was verified to be reasonable; the general methodology is universal and can be applicable to the hilly and gully region, Loess Plateau; (2) the erosion-type NPS total nitrogen (TN) and total phosphorus (TP) load showed an overall decreasing trend; the average nitrogen and phosphorus load modulus in the last four years (2009-2012) were 1.23 and 1.63 t/km(2) · a, respectively, which were both decreased by about 35.4 % compared with the initial treatment period (1995-1998); and (3) The spatial variations of NPS pollution are closely related to spatial characteristics of rainfall, topography, and soil and land use types; the peak regions of TN and TP loss mainly occurred along the main river banks of the Yanhe River watershed from northeast to southeast, and gradually decreased with the increase of distance to the left and right river banks, respectively. Results may provide scientific basis for the watershed-scale NPS pollution control of the Loess Plateau.

  7. Distribution of Hydrogen and Oxygen Isotopes in Salt Lakes of the Qinghai—Xizang Plateau,China

    Institute of Scientific and Technical Information of China (English)

    张保珍; 张彭熹; 等

    1990-01-01

    The Qinghai-Xizang Plateau is an area where a large number of salt lakes are distributed .We have collected several hundred samples of natural waters over the Plateau since 1976 and carried out researches on their hydrogen and oxygen isotopes.The results indicate that thd &D and &18O values of the salt lake waters over the Plateau range from -64.1 to +12.4‰ and from -11.19 to +8.62‰,respectively.From the different types of surfaces,ground and lake waters of various salinities it is inferred that the compositions of H and O isotopes in the initial water of Qinghai Lake are &D=55.0‰ and δ18O=-10.0‰,and those in the original water from the lakes in northern Xizang are δD=-116.0‰ and δ18O=-16.2‰.Brines in the salt lakes are derived from rain water through prolonged cir-culation.Oilfield water also makes some contribution to the salt lakes in the Qaidam Basin.Similar slopes of evaporation lines of water isotopes are noticed for the Qinghai Lake area and northern Xizang.This is attributed to the evolution of the isotopes in these water bodies in an environment of middle latitude and high elevation.

  8. Effects of soil drought on seedling growth and water metabolism of three common shrubs in Loess Plateau, Northwest China

    Institute of Scientific and Technical Information of China (English)

    AN Yuyan; LIANG Zongsuo; HAN Ruilian; LIU Guobin

    2007-01-01

    The growth and water metabolism of three common shrubs on the Loess Plateau were studied under soil with different water contents.Results showed that water consumption of those species decreased with the increase in drought stress,and water consumptions of these shrubs were different:Forsythia suspensa was the greatest,and Syringa oblata was the lowest.The growth rate of new branches and leaf area of three species were the fastest under adequate soil water conditions,and were the lowest under severe drought.Under the same water conditions,the growth ofF.suspensa was the fastest while that ofS.oblata was the slowest.The water content,proline and chlorophyll content of different species changed with the increase in soil water stress.The leaf water content of Periploca sepium and F.suspensa was obviously higher than that of S.oblata,while the leaf proline content of F.suspensa and S.oblata was lower than that ofP sepium.The ratio leaf chlorophyll a:b of F.suspensa and S.oblata decreased with the decrease in soil water content.Although these three shrubs had different mechanisms in response to drought stress,they all had higher drought resistance and could adapt to the drought condition on the Loess Plateau.This paper provided some bases for choosing tree species on the Loess Plateau.

  9. Decadal Relationship Between Atmospheric Heat Source and Winter-Spring Snow Cover over the Tibetan Plateau and Rainfall in East China

    Institute of Scientific and Technical Information of China (English)

    ZHU Yuxiang; DING Yihui; XU Huaigang

    2008-01-01

    By using a reverse computation method and the NCEP/NCAR daily reanalysis data from 1960 to 2004,the atmospheric heat source(AHS)was calculated and analyzed.The resuIts show that AHS over the Tibetan Plateau(TP)and its neighboring areas takes on a persistent downtrend in spring and summer during the foregone 50 years.especially the latest 20 years.Snow depth at 50 stations over the TP in winter and spring presents an increase,especially the spring Snow depth exhibits a sharp increase in the late 1970s.A close negative correlation exists between snow cover and AHS over the TP and its neighboring areas,as revealed by an SVD analysis,namely if there is more snow over the TP in winter and spring,then the weaker AHS would appear over the TP in spring and summer.The SVD analysis between AHS over the TP in spring and summer and rainfall at 160 stations indicates that the former has a negative correlation with summer precipitation in the middle and lower reaches of the Yangtze River,and a positive correlation with that in South China and North China.The SVD allalysis of both snow cover over the TP in winter and spring and rainfall at the same 160 stations indicates that the former has a marked positive correlation with precipitation in the middle and lower reaches of the Yangtze River,and a reversed correlation in South China and North China.On the decadal scale,the AHS and winter and spring snow cover over the TP have a close correlation with the decadal precipitation pattern shift(southern flood and northern drought)in East China.The mechanism on how the AHS over the TP influences rainfall in East China is discussed.The weakening of AHS over the TP in spring and summer reduces the thermodynamic diirerence between ocean and continent,leading to a weaker East Asian summer monsoon,which brings more water vapor to the Yangtze Rivet Valley and less water vapor to North China.Meanwhile.the weakening of AHS over the TP renders the position of the subtropical high further

  10. Regional water footprints of potential biofuel production in China.

    Science.gov (United States)

    Xie, Xiaomin; Zhang, Tingting; Wang, Liming; Huang, Zhen

    2017-01-01

    Development of biofuels is considered as one of the important ways to replace conventional fossil energy and mitigate climate change. However, rapid increase of biofuel production could cause other environmental concerns in China such as water stress. This study is intended to evaluate the life-cycle water footprints (WF) of biofuels derived from several potential non-edible feedstocks including cassava, sweet sorghum, and Jatropha curcas in China. Different water footprint types including blue water, green water, and grey water are considered in this study. Based on the estimated WF, water deprivation impact and water stress degree on local water environment are further analyzed for different regions in China. On the basis of the feedstock resource availability, sweet sorghum, cassava, and Jatropha curcas seeds are considered as the likely feedstocks for biofuel production in China. The water footprint results show that the feedstock growth is the most water footprint intensive process, while the biofuel conversion and transportation contribute little to total water footprints. Water footprints vary significantly by region with climate and soil variations. The life-cycle water footprints of cassava ethanol, sweet sorghum ethanol, and Jatropha curcas seeds biodiesel were estimated to be 73.9-222.2, 115.9-210.4, and 64.7-182.3 L of water per MJ of biofuel, respectively. Grey water footprint dominates the life-cycle water footprint for each type of the biofuels. Development of biofuels without careful water resource management will exert significant impacts on local water resources. The water resource impacts vary significantly among regions. For example, based on blue and grey water consumption, Gansu province in China will suffer much higher water stress than other regions do due to limited available water resources and large amount of fertilizer use in that province. In term of blue water, Shandong province is shown with the most severe water stress issue

  11. Regional Differences in China's Energy Efficiency and Conservation Potentials

    Institute of Scientific and Technical Information of China (English)

    Shi Dan

    2007-01-01

    This paper investigates the maximum energy efficiency level and the energy saving potentials in each region in China that can be practically attained at current economic and technological development levels. Most of the nation's energy efficient provinces are found along the coast of southeast China, while most of its least energy efficient provinces are in the hinterland that is rich in coal resources, and which depends heavily on coal consumption. China's low efficiency in energy resource allocation stems from its secondary industry, which is handicapped by the lowest energy efficiency and the most striking regional differentials. 4comparison of the factors affecting the energy efficiency shows that the provinces being compared in this study differ tremendously in energy consumption structure, technological level of the secondary industry, and abundance of energy resources, and that the other factors are only adequate, rather than necessary, conditions. It is imperative to rectify the behaviors of provinces in balancing local energy allocation, to channel energy resources to energy efficient provinces, and to improve the national energy efficiency as a whole. When taking energy-saving steps, provinces must take into full consideration both the national and local factors that affect energy efficiency. Furthermore, it is unrealistic for China to set a unified energy saving goal for different provinces.

  12. Thrusting and exhumation of the southern Mongolian Plateau: Joint thermochronological constraints from the Langshan Mountains, western Inner Mongolia, China

    Science.gov (United States)

    Feng, Li-Xia; Brown, Roderick W.; Han, Bao-Fu; Wang, Zeng-Zhen; Łuszczak, Katarzyna; Liu, Bo; Zhang, Zhi-Cheng; Ji, Jian-Qing

    2017-08-01

    The Mongolian Plateau has undergone multi-stage denudation since the Late Triassic, and the NE-trending Langshan Mountains in the southern margin of the Mongolian Plateau is crucial to unraveling the Meso-Cenozoic cooling and exhumation history of the Mongolian Plateau. The Langshan Mountains are dominated by Precambrian gneiss and Permian-Middle Triassic granitic plutons crosscut by a set of NE-striking thrust faults. A joint thermochronological study was conducted on 31 granitic and gneissic samples along the HQ and CU transects across the Langshan Mountains and other two samples from the BQ in the north of the Langshan Mountains. Four biotite/muscovite and three K-feldspar 40Ar/39Ar plateau ages range from 205 ± 1 to 161 ± 1 and 167 ± 1 to 131 ± 1 Ma, respectively. Thirty-three apatite fission track (AFT) ages are between 184 ± 11 and 79 ± 4 Ma, with mean track lengths from 11.1 ± 1.8 to 13.1 ± 1.4 μm of mostly unimodal distributions. Thirty-one single-grain raw AHe ages are in a range of 134 ± 8 to 21 ± 1 Ma. The AFT ages decrease monotonously from NW to SE until thrust faults along the two transects, with an age-jump across thrust F35. Joint thermal history modelling shows a three-stage cooling history as a result of denudation, especially with spatial differentiation in the first stage. Relative slow cooling at c. 0.6-1.0 °C/Ma occurred in the BQ and the northern part of the HQ transect during 220-100 Ma and the northern part of the CU transect during 160-100 Ma, respectively, with an amount of c. 2-3 km denudation between 160 and 100 Ma, implying little movement along the thrusts F13 and F33. In the middle and southern parts of the HQ transect and the southern part of the CU transect, rapid cooling at c. 4.0-7.0 °C/Ma, with c. 6-9 km denudation during 170-130 or 160-100 Ma, respectively, is probably influenced by thrusting of F35, F38 and F42 and the resultant tilting. A combination of thrusting, tilting, and denudation led to the youngering

  13. Spatial analysis on China's regional air pollutants and CO2 emissions: emission pattern and regional disparity

    Science.gov (United States)

    Dong, Liang; Liang, Hanwei

    2014-08-01

    China has suffered from serious air pollution and CO2 emission. Challenges of emission reduction policy not only come from technology advancement, but also generate from the fact that, China has pronounced disparity between regions, in geographical and socioeconomic. How to deal with regional disparity is important to achieve the reduction target effectively and efficiently. This research conducts a spatial analysis on the emission patterns of three air pollutants named SO2, NOx and PM2.5, and CO2, in China's 30 provinces, applied with spatial auto-correlation and multi regression modeling. We further analyze the regional disparity and inequity issues with the approach of Lorenz curve and Gini coefficient. Results highlight that: there is evident cluster effect for the regional air pollutants and CO2 emissions. While emission amount increases from western regions to eastern regions, the emission per GDP is in inverse trend. The Lorenz curve shows an even larger unequal distribution of GDP/emissions than GDP/capita in 30 regions. Certain middle and western regions suffers from a higher emission with lower GDP, which reveal the critical issue of emission leakage. Future policy making to address such regional disparity is critical so as to promote the emission control policy under the “equity and efficiency” principle.

  14. The Third Pole Environment Programme (TPE): A new base for the processes study of atmospheric physics and environment over the Tibetan Plateau and surrounding regions

    Science.gov (United States)

    Ma, Yaoming

    2016-04-01

    The Tibetan Plateau, with the most prominent and complicated terrain on the globe and an elevation of more than 4000 m on average above sea leave (msl), is often called the "Third Pole" due to its significance parallel with Antarctica and the Arctic. The exchange of energy, water vapor and some greenhouse gases between land surface and atmosphere over the Tibetan Plateau and the surrounding regions play an important role in the Asian monsoon system, which in turn is a major component of both the energy and water cycles of the global climate system. Supported by the Chinese Academy of Sciences and some international organizations, a Third Pole Environment (TPE) Research Platform (TPEP) is now implementing over the Tibetan Plateau and surrounding region. The background of the establishment of the TPEP, the establishing and monitoring plan of long-term scale (5-10 years) of the TPEP will be shown firstly. Then the preliminary observational analysis results, such as the characteristics of land surface heat fluxes, CO2 flux and evapotranspiration (ET) partitioning (diurnal variation, inter-monthly variation and vertical variation etc), aerosol optical properties between southern and northern sides of the Himalayas, the characteristics of atmospheric and soil variables, the structure of the Atmospheric Boundary Layer (ABL) and the turbulent characteristics have also been shown in this study.

  15. Weathering of Pisha-Sandstones in the Wind-Water Erosion Crisscross Region on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Two types of pisha-sandstones of purple sandstones and gray sandstones, widely distributing in the wind-water erosion crisscross region of China, were selected and used in laboratory experiments for a better understanding of the drying-wetting-freezing weathering process resulting from the apportionment of water or salt solution to rock samples. Weathering experiments were carried out under the conditions of environment control (including temperature, moisture and salt solution). All rock samples were frequently subjected to 140 drying-wetting-freezing cycles. The influences of weathering process were evaluated. It was found that the different treatments of moisture and salt solution applications could affect the nature of the weathering products resulting from drying-wetting-freezing. It was also observed that salt solution could effectively alleviate the weathering of pisha-sandstones. Although not all the observations could be explained, it was apparent that simulated environmental factors had both direct and indirect effects on the weathering of rocks.

  16. 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.

  17. Major Fault Systems and Mountain Building Processes in the Tibetan Foreland and Beishan Region, NW China

    Science.gov (United States)

    Cunningham, D.; Zhang, J.

    2012-04-01

    In regions north of Tibet, active deformation associated with the Indo-Eurasia collision is diffusely distributed within large areas of NW China, Mongolia and S and SE Siberia. These regions are dominated by intraplate strike-slip and transpressional reactivation of Palaeozoic terrane collages. Because of relatively low historical seismicity, the Beishan region immediately north of Tibet is generally regarded as tectonically uninteresting from a neotectonic standpoint. However, our preliminary work in the region coupled with satellite image analysis indicates that the region is cut by at least five major sinistral strike-slip fault systems that are potentially active and which parallel the Altyn Tagh fault which bounds northern Tibet directly to the south. These fault systems generate localised uplifts within the Beishan and show typical geomorphological characteristics of active intracontinental deforming belts such as sharply defined mountain fronts, Quaternary alluvial fan complexes and tilted Cretaceous peneplain remnants. Specifically, the Yushi Shan and Mazong Shan are Late Cenozoic restraining bends that show clear evidence for Quaternary thrusting and uplift. Other minor localised uplifts also appear fault-controlled. However, at first-order, regional Beishan topography is difficult to explain by Late Cenozoic upper crustal faulting, unlike Tibet to the south and the Gobi Altai to the north. Directly adjacent to Tibet's northern margin, the Sanweishan and Nanjieshan blocks are thrust-bound basement-cored uplifts that interrupt the Tibetan sedimentary foreland in the Dunhuang-Anxi region. The faults that cut and bound these minor ranges appear to define an evolving transpressional duplex with north-directed thrusting, but perhaps surprisingly, also south-directed thrusting back towards the high Plateau. As noted by others, the Altyn Tagh Fault defines a profound topographic and structural boundary in Central Asia with significant differences in contractional

  18. Nutritional constituents of soybean grown in northeast region of China

    OpenAIRE

    Yu Zou; Chenghui LIU

    2016-01-01

    Nutritional constituents of soybeans (Glycine max L. Merr.) grown in the Northeast Region of China were evaluated through measuring amino acid composition, fatty acid profile and mineral content. Results showed that there were eighteen detectable amino acids in soybean samples. The fatty acid profile indicated linoleic acid, oleic acid, palmitic acid and linolenic acid as the most abundant fatty acid followed by stearic acid, lauric acid, arachidonic acid, behenic acid and gondoic acid. Miner...

  19. Crustal deformation rates in Assam Valley, Shillong Plateau, Eastern Himalaya, and Indo-Burmese region from 11 years (2002-2013) of GPS measurements

    Science.gov (United States)

    Barman, Prakash; Jade, Sridevi; Shrungeshwara, T. S.; Kumar, Ashok; Bhattacharyya, Sanjeev; Ray, Jagat Dwipendra; Jagannathan, Saigeetha; Jamir, Wangshi Menla

    2017-09-01

    The present study reports the contemporary deformation of the tectonically complex northeast India using 11 years (2002-2013) of GPS observations. The central Shillong Plateau and few sites north of Plateau located in Assam Valley behave like a rigid block with 7 mm/year India-fixed southward velocity. The Euler pole of rotation of this central Shillong Plateau-Assam Valley (SH-AS) block is estimated to be at -25.1° ± 0.2°N, -97.8° ± 1.8°E with an angular velocity of 0.533° ± 0.10° Myr-1 relative to India-fixed reference frame. Kopili fault located between Shillong Plateau and Mikir massif records a dextral slip of 4.7 ± 1.3 mm/year with a locking depth of 10.2 ± 1.4 km indicating the fragmentation of Assam Valley across the fault. Presently, western edge of Mikir massif appears to be locked to Assam block indicating strain accumulation in this region. First-order elastic dislocation modelling of the GPS velocities estimates a slip rate of 16 mm/year along the Main Himalayan Thrust in Eastern Himalaya which is locked over a width of 130 km from the surface to a depth of 17 km with underthrusting Indian plate. Around 9 mm/year arc-normal convergence is accommodated in Lesser Himalaya just south of Main Central Thrust indicating high strain accumulation. Out of 36 mm/year (SSE) India-Sunda plate motion, about 16 mm/year motion is accommodated in Indo-Burmese Fold and Thrust Belt, both as normal convergence ( 6 mm/year) and active slip ( 7-11 mm/year) in this region.

  20. Establishment of nature reserves in administrative regions of mainland China.

    Directory of Open Access Journals (Sweden)

    Ziliang Guo

    Full Text Available Nature reserves are widely considered as one available strategy for protecting biodiversity, which is threatened by habitat fragmentation, and wildlife extinction. The Chinese government has established a goal of protecting 15% of its land area by 2015. We quantitated the characteristics and distribution of nature reserves in mainland China and evaluated the expansion process for national nature reserves. National nature reserves occupy 64.15% of the total area of nature reserves. Steppe and meadow ecosystem, ocean and seacoast ecosystem, and wild plant nature reserves represent lower percentages, particularly in national nature reserves, in which they comprised 0.76%, 0.54%, and 0.69%, respectively, of the area. Furthermore, medium and small nature reserves compose 92.32% of all nature reserves. The land area under any legal protection has reached 14.80%, although only 9.78% is strictly protected. However, if 9 super-large national nature reserves, located in Southwest and Northwest China were removed, the percentage of strictly protected area decreases to 2.66% of the land area of China. The areas contained in nature reserves in each province are not proportional to the areas of the provinces, particularly for national nature reserves, with higher protection rates in Southwest and Northwest China than in other regions. Of the 31 provinces, 22 provinces feature strict protection of less than 4% of their areas by national nature reserves; these provinces are mainly located in East, Central, South, and North China. Moreover, the unevenness indexes of the distribution of nature reserves and national nature reserves are 0.39 and 0.58, respectively. The construction of nature reserves has entered a steady development stage after a period of rapid expansion in mainland China. In recent years, the total area of national nature reserves has increased slowly, while the total area of nature reserves has not increased, although the number of nature

  1. Hydrogeologic framework and hydrologic budget components of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Kahle, S.C.; Morgan, D.S.; Welch, W.B.; Ely, D.M.; Hinkle, S.R.; Vaccaro, J.J.; Orzol, L.L.

    2011-01-01

    The Columbia Plateau Regional Aquifer System (CPRAS) covers an area of about 44,000 square miles in a structural and topographic basin within the drainage of the Columbia River in Washington, Oregon, and Idaho. The primary aquifers are basalts of the Columbia River Basalt Group (CRBG) and overlying sediment. Eighty percent of the groundwater use in the study area is for irrigation, in support of a $6 billion per year agricultural economy. Water-resources issues in the Columbia Plateau include competing agricultural, domestic, and environmental demands. Groundwater levels were measured in 470 wells in 1984 and 2009; water levels declined in 83 percent of the wells, and declines greater than 25 feet were measured in 29 percent of the wells. Conceptually, the system is a series of productive basalt aquifers consisting of permeable interflow zones separated by less permeable flow interiors; in places, sedimentary aquifers overly the basalts. The aquifer system of the CPRAS includes seven hydrogeologic units-the overburden aquifer, three aquifer units in the permeable basalt rock, two confining units, and a basement confining unit. The overburden aquifer includes alluvial and colluvial valley-fill deposits; the three basalt units are the Saddle Mountains, Wanapum, and Grande Ronde Basalts and their intercalated sediments. The confining units are equivalent to the Saddle Mountains-Wanapum and Wanapum-Grande Ronde interbeds, referred to in this study as the Mabton and Vantage Interbeds, respectively. The basement confining unit, referred to as Older Bedrock, consists of pre-CRBG rocks that generally have much lower permeabilities than the basalts and are considered the base of the regional flow system. Based on specific-capacity data, median horizontal hydraulic conductivity (Kh) values for the overburden, basalt units, and bedrock are 161, 70, and 6 feet per day, respectively. Analysis of oxygen isotopes in water and carbon isotopes in dissolved inorganic carbon from

  2. On the contrasting decadal changes of diurnal surface temperature range between the Tibetan Plateau and southeastern China during the 1980s-2000s

    Science.gov (United States)

    Yang, Yang; Ren, Rongcai

    2017-02-01

    The diurnal surface temperature range (DTR) has become significantly smaller over the Tibetan Plateau (TP) but larger in southeastern China, despite the daily mean surface temperature having increased steadily in both areas during recent decades. Based on ERA-Interim reanalysis data covering 1979-2012, this study shows that the weakened DTR over TP is caused by stronger warming of daily minimum surface temperature (Tmin) and a weak cooling of the daily maximum surface temperature (Tmax); meanwhile, the enhanced DTR over southeastern China is mainly associated with a relatively stronger/weaker warming of Tmax/Tmin. A further quantitative analysis of DTR changes through a process-based decomposition method—the Coupled Surface-Atmosphere Climate Feedback Response Analysis Method (CFRAM)—indicates that changes in radiative processes are mainly responsible for the decreased DTR over the TP. In particular, the increased low-level cloud cover tends to induce the radiative cooling/warming during daytime/nighttime, and the increased water vapor helps to decrease the DTR through the stronger radiative warming during nighttime than daytime. Contributions from the changes in all radiative processes (over -2°C) are compensated for by those from the stronger decreased surface sensible heat flux during daytime than during nighttime (approximately 2.5°C), but are co-contributed by the changes in atmospheric dynamics (approximately -0.4°C) and the stronger increased latent heat flux during daytime (approximately -0.8°C). In contrast, the increased DTR over southeastern China is mainly contributed by the changes in cloud, water vapor and atmospheric dynamics. The changes in surface heat fluxes have resulted in a decrease in DTR over southeastern China.

  3. Water and heat exchanges on the Tibetan Plateau: observation and modeling of the yellow river source region

    NARCIS (Netherlands)

    Zheng, D.

    2015-01-01

    Understanding the water and heat exchanges across the Tibetan ecosystem is of great importance for management of the Asian water towers that originate from the Tibetan Plateau and projection of water and energy dynamics within various climate scenarios. The study presented in this book contributes t

  4. The 3rd China Standardization Forum Held in Urumqi, Xinjiang Uygur Autonomous Region

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ On Aug. 14th-15th, the 3rd China Standardization Forum, hosted by Standardization Administration of China(SAC), sponsored by China Association for Standardization (CAS) and associated by the Bureau of Quality &Technical Supervision of Xinjiang Uygur Autonomous Region of the People's Republic of China, was held in Urumqi, Xinjiang.

  5. Japan's response to China's rise : regional engagement, global containment, dangers of collision

    OpenAIRE

    Hughes, Christopher W.

    2009-01-01

    Japan and China's ability to manage their bilateral relationship is crucial for the stability of the East Asian region. It also has a global impact on the security and economic development of other regions. For just as China's rise has inevitably involved an expansion of its global reach, so Japan's responses to the challenges posed by China have increasingly taken a global form, seeking to incorporate new partners and frameworks outside East Asia. Japan's preferred response to China's region...

  6. Patterns of shrub species richness and abundance in relation to environmental factors on the Alxa Plateau:Prerequisites for conserving shrub diversity in extreme arid desert regions

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Shrub species are considered the dominant plants in arid desert ecosystems,unlike in semiarid steppe zones or in grassland ecosystems.On the Alxa Plateau,northern China,sparse vegetation with cover ranging from 15% to 30% is characterized mainly by multifarious shrubs because herbaceous species are strongly restricted by the extreme drought climate,wind erosion,overgrazing and sand burial.Patterns in shrub species richness and species abundance in relation to environmental conditions were examined by DCA(detrended correspondence analysis) and interpreted by a biplot.The rela-tionships between species diversity and environmental factors were examined using regression analyses.Our results show that the distributions of the shrub species in response to environmental conditions can be grouped into four ecological types,corresponding with the biological traits of the shrubs and their responses to the gradients of soil texture and soil water content.Patterns in species richness and species abundance were mainly determined by the deeper soil water content,instead of the soil texture as hypothesized by numerous studies in semiarid grasslands.With exception of the deeper soil water content,soil organic matter and total N content were positively correlated with species abundance,while pH was negatively correlated with it.These findings imply that it is vital for cur-rent shrub diversity conservation to reduce agricultural water use in the middle reaches of the Heihe River,which supplies water for the lower reaches in the western parts of the plateau,and to reduce the amount of groundwater exploitation and urban and oasis water use,to increase the water supply from Helan Mountain to the eastern desert of the Alxa Plateau.

  7. Patterns of shrub species richness and abundance in relation to environmental factors on the Alxa Plateau: Prerequisites for conserving shrub diversity in extreme arid desert regions

    Institute of Scientific and Technical Information of China (English)

    LI XinRong; TAN HuiJuan; HE MingZhu; WANG XinPing; LI XiaoJun

    2009-01-01

    Shrub species are considered the dominant plants in arid desert ecosystems, unlike in semiarid steppe zones or in grassland ecosystems. On the Alxa Plateau, northern China, sparse vegetation with cover ranging from 15% to 30% is characterized mainly by multifarious shrubs because herbaceous species are strongly restricted by the extreme drought climate, wind erosion, overgrazing and sand burial. Patterns in shrub species richness and species abundance in relation to environmental conditions were examined by DCA (detrended correspondence analysis) and interpreted by a biplot. The rela-tionships between species diversity and environmental factors were examined using regression analyses. Our results show that the distributions of the shrub species in response to environmental conditions can be grouped into four ecological types, corresponding with the biological traits of the shrubs and their responses to the gradients of soil texture and soil water content. Patterns in species richness and species abundance were mainly determined by the deeper soil water content, instead of the soil texture as hypothesized by numerous studies in semiarid grasslands. With exception of the deeper soil water content, soil organic matter and total N content were positively correlated with spe-cies abundance, while pH was negatively correlated with it. These findings imply that it is vital for cur-rent shrub diversity conservation to reduce agricultural water use in the middle reaches of the Heihe River, which supplies water for the lower reaches in the western parts of the plateau, and to reduce the amount of groundwater exploitation and urban and oasis water use, to increase the water supply from Helan Mountain to the eastern desert of the Alxa Plateau.

  8. Impacts of Abnormal Heating of Tibetan Plateau on Rossby Wave Activity and Hazards Related to Snow and Ice in South China

    Directory of Open Access Journals (Sweden)

    Yuyue Fan

    2015-01-01

    Full Text Available In January 2008, extreme freezing rain struck South China. At the same time, the Tibetan Plateau (TP was experiencing pronounced surface heating. The characteristics of this extreme weather and its linkage to the TP surface heating anomaly were analyzed in this paper. The results show that (1 anomalous heating of the TP helps to form and sustain the Siberian blocking high, which is important for persistent southward flow of dry and cold Siberian air; (2 TP heating helps the moisture flux move more north and strengthens the southerly wind above 850 hPa; (3 there are two Rossby wave trains at 500 hPa and the layers above it (at about 20∘N–40∘N. Correlation analysis reveals that TP heating anomalies are closely associated with these Rossby wave trains; (4 the Rossby wave propagates downstream from the TP to South China in the mid and high layers of the atmosphere when the TP changes swiftly from a heat sink to a heat source. This implies that anomalous heating of the TP may stimulate the Rossby wave train to propagate downward in midlatitudes.

  9. Reconstruction of paleo-particulate organic carbon fluxes for the Campbell Plateau region of southern New Zealand using the zinc content of sponge spicules

    Science.gov (United States)

    Ellwood, Michael J.; Kelly, Michelle; Neil, Helen; Nodder, Scott D.

    2005-09-01

    The zinc concentration of siliceous sponge spicules was determined from spicules recovered from four sediment cores spanning the last 160 kyr, from the Campbell Plateau region southeast of New Zealand. Zinc/Si results showed little difference between Holocene and glacial aged spicules. An increase in Zn/Si was observed for core Y14, where Zn/Si peaked at about 0.6 μmol/mol during marine isotope stages 5a-5b. To better understand the role carbon export has on sponge Zn/Si, we explored the strong relationship observed between surficial sediment particulate organic carbon (POC) and the Zn/Si of sponge silica and related this to sediment trap POC flux estimates. Conversion of the Zn/Si records to benthic POC fluxes suggests that there has been little change in the amount of POC reaching Campbell Plateau sediments over the past 30 kyr. These results suggest that surface productivity over the Campbell Plateau has remained relatively low over the past 160 kyr and suggests that glacial productivity was not significantly higher than the present day. Finally, this work reveals that living marine sponges appear to act as the biological equivalents of moored sediment traps, recording the flux of POC to the seafloor by archiving zinc associated with sinking POC in the growing silica skeleton.

  10. Integrating Regional Development, Promoting Local Cooperation Reflections on the China-UK Regional Leaders Exchange Program

    Institute of Scientific and Technical Information of China (English)

    Liu; Chang

    2016-01-01

    The first China-UK Regional Leaders Meeting was held March21-24 in the United Kingdom,both in London and the industrial city of Sheffield.The event was jointly organized by the CPAFFC and the British Department for Communities and Local Government.The Chinese delegation,comprising government

  11. Attribution of Runoff Change for the Xinshui River Catchment on the Loess Plateau of China in a Changing Environment

    Directory of Open Access Journals (Sweden)

    Guoqing Wang

    2016-06-01

    Full Text Available Stream flow plays a crucial role in the environment, society, and the economy, and identifying the causes of changes in runoff is important to understanding the impact of climate change and human activity. This study examines the variation trends in recorded runoff for the Xinshui River, a tributary of the Yellow River on the Loess Plateau, and uses hydrological simulations to investigate how climate change and human activity have contributed to those trends. Results show that the recorded runoff at the Daning station on the Xinshui River declined significantly from 1955–2008 with an abrupt change occurring in 1973. The Simplified Water Balance Model (SWBM simulates monthly discharge well with a Nash–Sutcliffe efficiency (NSE coefficient of 78% and a relative error of volumetric fit (RE of 0.32%. Runoff depth over the catchment in 1973–2008 fell by 25.5 mm relative to the previous period, with human activity and climate change contributing 60.6% and 39.4% of the total runoff reduction, respectively. However, the impacts induced by climate change and human activities are both tending to increase. Therefore, efforts to improve the ecology of the Loess Plateau should give sufficient attention to the impacts of climate change and human activity.

  12. A Communal Sign Post of Snow Leopards (Panthera uncia and Other Species on the Tibetan Plateau, China

    Directory of Open Access Journals (Sweden)

    Juan Li

    2013-01-01

    Full Text Available The snow leopard is a keystone species in mountain ecosystems of Central Asia and the Tibetan Plateau. However, little is known about the interactions between snow leopards and sympatric carnivores. Using infrared cameras, we found a rocky junction of two valleys in Sanjiangyuan area on the Tibetan Plateau where many mammals in this area passed and frequently marked and sniffed the site at the junction. We suggest that this site serves as a sign post to many species in this area, especially snow leopards and other carnivores. The marked signs may also alert the animals passing by to temporally segregate their activities to avoid potential conflicts. We used the Schoener index to measure the degree of temporal segregation among the species captured by infrared camera traps at this site. Our research reveals the probable ways of both intra- and interspecies communication and demonstrates that the degree of temporal segregation may correlate with the degree of potential interspecies competition. This is an important message to help understand the structure of animal communities. Discovery of the sign post clarifies the importance of identifying key habitats and sites of both snow leopards and other species for more effective conservation.

  13. Pollution characteristics and ecological risk assessment of heavy metals in three land-use types on the southern Loess Plateau, China.

    Science.gov (United States)

    Zhang, Yubin; Wu, Faqi; Zhang, Xinsheng; Cao, Ning

    2017-08-25

    The accumulation of heavy metals in agricultural soils has been the subject of great concern because these metals have the potential to be transferred to soil solutions and subsequently accumulate in the food chain. To study the persistence of trace metals in crop and orchard soils, representative surface soil samples were collected from terrace farmland that had been cultivated for various numbers of years (3, 8, 12, 15, and >20 years), terrace orchard land that had been cultivated for various numbers of years (4, 7, 10, 12, 15, 18, 25, and >30 years), and slope farmland with various gradients (3°, 5°, 8°, 12°, 15°, and 25°) and analyzed for heavy metals (As, Cr, Cu, Hg, Ni, and Zn). These samples were collected from Nihegou catchment of Chunhua county in the southern Loess Plateau of China. The six heavy metals demonstrated different trends with time or gradient in the three land-use types. The Cu and Zn contents of the soil were higher than the referee background values of the loessal soil, and the contents of Cr and Ni, and especially those of As and Hg, were lower. Cu was the only heavy metal that just met the Grade III Environmental Quality Standard for Soils of China, while the others reached grade I. Cu and Hg were considered contaminant factors and Hg was a moderate potential ecological risk factor in the catchment. Of the sites investigated, 89.5% fell into the category with a low degree of contamination (C d ) and rest were moderate, while all three land-use types had low potential ecological risk (RI). Changes of C d and RI were consistent with the cultivated time in the terrace farmland and terrace orchard land. Values of RI increased while C d decreased with the increasing of slope gradient in the slope farmland. Evaluating the ecological risk posed by heavy metals using more soil samples in a larger study area is necessary on the Loess Plateau of China.

  14. Greening the Plateau

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Located on the world’s largest plateau, Tibet Autonomous Region in China’s southwest has an average elevation of 4,000 meters. Tibet’s diverse natural landscapes, including snow-capped mountains, vast pastures and virgin forests, combined with its

  15. Impact of China-ASEAN Free Trade Area on China's International Agricultural Trade and Its Regional Development

    Institute of Scientific and Technical Information of China (English)

    Huanguang Qiu; Jun Yang; Jikun Huang; Ruijian Chen

    2007-01-01

    This study aims to examine the impact of the China-ASEAN Free Trade Area (CAFTA) on China's international agricultural trade and its regional agricultural development, using the Global Trade Analysis Project model and the China Agricultural Decision Support System. Our analysis showed that: (i) CAFTA will improve resource allocation efficiencies for both China and ASEAN and will promote bilateral agricultural trade and, hence, will have positive effects on the economic development of both sides; (ii) CAFTA will accelerate China's export of the agricultural commodities in which it has comparative advantages,such as vegetables, wheat and horticultural products, but at the same time bring about a large increase in imports of commodities such as vegetable oil and sugar; and (iii) CAFTA will have significantly varying impacts on China's regional agricultural development because of large differences in the agricultural production structure in each region. Our results indicate that agriculture in the northern, northeastern and eastern regions of China will benefit from CAFTA, whereas agriculture development in southern China will suffer Those regional specific impacts are quite different from the effects brought by multilateral free trade treaties, such as those of the WTO, which usually have positive effects on south China but negative impacts on the northern and western parts of China.

  16. Decomposition of different plant litters in Loess Plateau of Northwest China%黄土高原不同植物凋落物的分解特性

    Institute of Scientific and Technical Information of China (English)

    李云; 周建斌; 董燕捷; 夏志敏; 陈竹君

    2012-01-01

    Taking the litters of species Hippophae rhamnoides, Medicago sativa, Populus simonii, Robinia pseudoacaci, Salix psammophila, and Stipa bungeana in the Loess Plateau of Northeast China as test objects, and by using mesh bags, this paper studied the dynamic changes of the litters mass, carbon, and nitrogen during decomposition after buried in the field in semiarid region. The litters buried were from one, two, or three of the plant species, and mixed thoroughly with equal proportion of masses. During decomposition, the mass loss rate, total carbon and nitrogen release rates, and total soluble carbon and nitrogen contents of different litters were higher at the early than at the later decomposition stage. After 412 d decomposition, the average mass loss rate of the litters was in the order of mixed litters of three plant species > mixed litters of two plant species > one plant species litter. By the end of this experiment, the average release rates of the litter total carbon and nitrogen ranked as one plant species litter > mixed litters of two plant species > mixed litters of three plant species, the litter soluble organic carbon content was mixed litters of two plant species > mixed litters of three plant species > one plant species litter, while the litter soluble total nitrogen content was mixed litters of three plant species > mixed litters of two plant species > one plant species litter. Correlation analysis showed that the utter mass loss rate had definite correlation with the litter soluble organic matter, especially soluble organic carbon. From the viewpoint of mass loss rate, the mixture of the litters of P. simonii, H. rhamnoide, and M. sativa was the optimum. It was suggested that in the process of returning farmland into forestland and grassland in the gully and valley region of Loess Plateau, it would be required to rationally increase plant species diversity to improve soil fertility.%以黄土高原区典型植物刺槐、小叶杨、沙棘、沙柳

  17. Alternative zoning scenarios for regional sustainable land use controls in China: a knowledge-based multiobjective optimisation model.

    Science.gov (United States)

    Xia, Yin; Liu, Dianfeng; Liu, Yaolin; He, Jianhua; Hong, Xiaofeng

    2014-08-28

    Alternative land use zoning scenarios provide guidance for sustainable land use controls. This study focused on an ecologically vulnerable catchment on the Loess Plateau in China, proposed a novel land use zoning model, and generated alternative zoning solutions to satisfy the various requirements of land use stakeholders and managers. This model combined multiple zoning objectives, i.e., maximum zoning suitability, maximum planning compatibility and maximum spatial compactness, with land use constraints by using goal programming technique, and employed a modified simulated annealing algorithm to search for the optimal zoning solutions. The land use zoning knowledge was incorporated into the initialisation operator and neighbourhood selection strategy of the simulated annealing algorithm to improve its efficiency. The case study indicates that the model is both effective and robust. Five optimal zoning scenarios of the study area were helpful for satisfying the requirements of land use controls in loess hilly regions, e.g., land use intensification, agricultural protection and environmental conservation.

  18. Trends and responses to global change of China's arid regions

    Institute of Scientific and Technical Information of China (English)

    Weixi YANG

    2009-01-01

    Ⅰ analyzed and elaborated the trends in and responses to global change in arid regions of China, from the perspective of nine variables, i.e., temperature, precipitation, river runoff, melting glaciers, water level of lakes, wind power and evaporation, vegetation, oases, and desertification. The climate and hydrology data Ⅰ citedrepresent many years of observations. Ⅰ conclude that, since the 1980s, the climate in arid regions of China has clearly changed with rising temperatures and precipitation in most areas. Wind power and the number of galestorm days have continuously decreased, which resulted in an improvement of humid conditions and increases in river discharge and water levels of lakes. Simultaneously, vegetation also has improved and the process of deserti-fication has essentially been arrested. Although there are some unfavorable developments, such as decreased river flows or flow interruptions and downstream oases have suffered from degradation, these incidental cases should not distract our attention from the generally favorable trends during the middle and late 20th century. These discordant phenomena are not consequences of climate change but rather of unsuitable human activities. Despitea substantial increase in precipitation, the level of the original precipitation was so small that any increase in precipitation was still small. As a result, none of the fundamental conditions such as a scarcity of water resources and precipitation nor the landscape of drought-ridden deserts in the arid regions will change. The vulnerability of the eco-environmental system in the arid regions will not change fundamentally either in the near future.

  19. Climatic Signals in the Last 200 Years from Stable Isotope Record in the Shells of Freshwater Snails in Lake Xingcuo, Eastern Tibet Plateau, China

    Institute of Scientific and Technical Information of China (English)

    WU JINGLU(吴敬禄); LI SHIJIE(李世杰); A.LUECKE; WANG SUMIN(王苏民)

    2002-01-01

    Lake Xingcuo is a small closed, hard-water lake, situated on eastern Tibet Plateau.Stable isotope data (δ 18O and δ 13C) from the freshwater snail Gyraulus sibirica (Dunker) in a 34 cm long, radioactive isotope-dated sediment core represent the last 200 years of Lake Xingcuo environmental history. Carbon and oxygen isotope ratios in the shells of the freshwater snail bear information on the isotopic composition of the water in which the shells were formed,which in turn characterizes the climatic conditions prevailing during the snail's life span.Whole-shell and incremental growth data were collected from modern and fossil shells from Lake Xingcuo. The δ 18O values of modern shells from Lake Xingcuo are in equilibrium with those of modern waters, while δ 13C values are indicative of snail dietary carbon and a lake with high δ 13CTDIC. By calibrating δ 18O and δ 13C in the shell Gyraulus sibirica (Dunker) with in strument-measured data for the period 1954 - 1992, we found that the δ 18O of the snail shells is an efficient indicator to reveal air temperature in the warmer half year instead of that around the whole year, and that there is a certain positive correlation between index δ 18O and the running average temperature in the warmer half-year period. Climatic variability on eastern Tibet Plateau, for the last two centuries, has been successfully inferred from the δ 18O record in freshwater snails in the sediments of Lake Xingcuo. As such, the last 200 years of palaeoclimatic record for this region can be separated into three periods representing oscillations between warming and cooling, which are confirmed by the Guliya ice record on the Tibet Plateau.

  20. Climatic Signals in the Last 200 Years from Stable Isotope Record in the Shells of Freshwater Snails in Lake Xingcuo,Eastern Tibet Plateau,China

    Institute of Scientific and Technical Information of China (English)

    吴敬禄; A.LUECKE; 等

    2002-01-01

    Lake Xingcuo is a small closed,hard-water lake ,situated on eastern Tibet Plateau.Stable isotope data(δ18O and δ13C) from the freshwater snail Gyraulus sibirica(Dunker)in a34 cm long,radioactive isotope-dated sediment core represent the last 200 years of Lake Xingcuo environmental history.Carbon and oxygen isotope ratios in the shells of the freshwater snail bear information on the isotopic composition of the water in which the shells were formed ,which in turn characterizes the climatic conditions prevailing during the snail's life span.Whole-shell and incremental growth data were collected from modern and fossil shells from Lake Xingcuo.The δ18O values of modern shells from Lake Xingcuo are in equilibrium with high δ13CTDIC.By calibrating δ18O and δ13C in the shell Gyraulus sibirica(Dunker)with in-strument-measured data for the period 1954-1992,we found that the δ18O of the snail shells is an efficient indicator to reveal air temperature in the warmer half year instead of that around the whole year,and that there is a certain positive correlation between index δ18O and the run-ning average temperature in the warmer half-yiar period.Climatic variability on eastern Tibet Plateau,for the last two centuries,has been successfully inferred from the δ18O record in freshwater snails in the sediments of Lake Xingcuo.As such,the last 200 years of palaeocli-matic record for this region can be separated into three periods representing oscillations between warming and cooling,which are confirmed by the Guliya ice record on the Tibet Plateau.

  1. Climatic features of atmospheric heat source/sink over theQinghai-Xizang Plateau in 35 years and its relation torainfall in China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using the 1961—1995 monthly averaged meteorological data from 148 surface stationsin the Qinghai-Xizang Plateau (QXP) and its surrounding areas, calculation of the 35-year atmos-pheric heat source/sink () and an analysis on its climatic features and relation to rainfall inChina have been made. It is found that on the average, the atmospheric heat source over the QXPis the strongest in June (78 W / m2) and cold source is the strongest in December (-72 W/m2). Thesensible heat of the surface increases remarkably over the southwest of the QXP, causing the ob-vious increase of there in February and March, which makes a center of the atmospheric heatsource appear over the north slope of the Himalayas. Afterwards, this center continues to intensifyand experiences noticeable migration westwards twice, separately occurring in April and June. Thetime when the atmosphere over the east of the QXP becomes heat source and reaches strongestis one month later than that over the southwest of the QXP. In summer, the latent heat of conden-sation becomes a heating factor as important as the sensible heat and is also a main factor thatmakes the atmospheric heat source over the east of the QXP continue growing. On the interde-cadal time scale, of the QXP shows an abrupt change in 1977 and a remarkable increase after1977. The atmospheric heat source of the spring over the QXP is a good indicator for the subse-quent summer rainfall over the valleys of the Changjiang and Huaihe rivers and South China andNorth China. There is remarkable positive correlation between the QXP heat source of summerand the summer rainfall in the valleys of the Changjiang River

  2. Effects of straw and plastic film mulching on greenhouse gas emissions in Loess Plateau, China: A field study of 2 consecutive wheat-maize rotation cycles.

    Science.gov (United States)

    Chen, Haixin; Liu, Jingjing; Zhang, Afeng; Chen, Jing; Cheng, Gong; Sun, Benhua; Pi, Xiaomin; Dyck, Miles; Si, Bingcheng; Zhao, Ying; Feng, Hao

    2017-02-01

    Mulching practices have long been used to modify the soil temperature and moisture conditions and thus potentially improve crop production in dryland agriculture, but few studies have focused on mulching effects on soil gaseous emissions. We monitored annual greenhouse gas (GHG) emissions under the regime of straw and plastic film mulching using a closed chamber method on a typical winter-wheat (Triticum aestivum L. cv Xiaoyan 22) and summer-maize (Zea mays L. cv Qinlong 11) rotation field over two-year period in the Loess Plateau, northwestern China. The following four field treatments were included: T1 (control, no mulching), T2 (4000kgha(-1) wheat straw mulching, covering 100% of soil surface), T3 (half plastic film mulching, covering 50% of soil surface), and T4 (complete plastic film mulching, covering 100% of soil surface). Compared with the control, straw mulching decreased soil temperature and increased soil moisture, whereas plastic film mulching increased both soil temperature and moisture. Accordingly, straw mulching increased annual crop yields over both cycles, while plastic film mulching significantly enhanced annual crop yield over cycle 2. Compared to the no-mulching treatment, all mulching treatments increased soil CO2 emission over both cycles, and straw mulching increased soil CH4 absorption over both cycles, but patterns of soil N2O emissions under straw or film mulching are not consistent. Overall, compared to T1, annual GHG intensity was significantly decreased by 106%, 24% and 26% under T2, T3 and T4 over cycle 1, respectively; and by 20%, 51% and 29% under T2, T3 and T4 over cycle 2, respectively. Considering the additional cost and environmental issues associated with plastic film mulching, the application of straw mulching might achieve a balance between food security and GHG emissions in the Chinese Loess Plateau. However, further research is required to investigate the perennial influence of different mulching applications.

  3. Chemical and Sr isotopic characteristics of rainwater on the Alxa Desert Plateau, North China: Implication for air quality and ion sources

    Science.gov (United States)

    Rao, Wenbo; Han, Guilin; Tan, Hongbing; Jin, Ke; Wang, Shuai; Chen, Tangqing

    2017-09-01

    The major ions and Sr isotopes in rainwater have been studied during 2013-2015 on the Alxa Desert Plateau in order to identify the source of rainwater chemistry and to assess air quality in the desert area of northern China. The pH and EC values of rainwater vary from 6.7 to 8.1 and from 35 to 1237 μS cm- 1, respectively, at the two meteorological stations (AYQ and YBL) in the Alxa Desert Plateau. Ca2 +, SO42 -, Na+ and Cl- are the dominant ions in rainwater, possessing > 85% of total ions. The mean daily wet deposition fluxes of soluble ions are 8709 μeq/m2/d at YBL and 5459 μeq/m2/d at AYQ, approaching the values at Xi'an, Beijing, Guangzhou, and Chengdu. Statistical analysis shows that SO42 - and NO3- in rainwater were mainly from anthropogenic sources while Ca2 + and K+ originated from terrestrial sources. Cl- was mainly from seawater sources, and Na+ was partly from mineral weathering. Major ions are well correlated with each other in rainwater, revealing that substances of various origins were synchronously carried into the atmosphere by wind. By using Sr isotope techniques, three main end-members controlling base cations of rainwater are identified: silicates, carbonates and seawater. Based on the analyses of acid-soluble fractions of desert soils, local soil dust could be the most important source of base cations in rainwater whereas the effect of the anthropogenic sources could be neglected.

  4. Changes in soil organic carbon and total nitrogen in croplands converted to walnut-based agroforestry systems and orchards in southeastern Loess Plateau of China.

    Science.gov (United States)

    Lu, Sen; Meng, Ping; Zhang, Jinsong; Yin, Changjun; Sun, Shiyou

    2015-11-01

    Limited information is available on the effects of agroforestry system practices on soil properties in the Loess Plateau of China. Over the last decade, a vegetation restoration project has been conducted in this area by converting cropland into tree-based agroforestry systems and orchards to combat soil erosion and degradation. The objective of the present study was to determine the effects of land use conversion on soil organic carbon and total nitrogen in southeastern Loess Plateau. The experiment included three treatments: walnut intercropping system (AF), walnut orchard (WO), and traditional cropland (CR). After 7 years of continual management, soil samples were collected at 0-10, 10-30, and 30-50-cm depths for three treatments, and soil organic carbon (SOC) and total nitrogen (TN) were measured. Results showed that compared with the CR and AF treatments, WO treatment decreased both SOC and TN concentrations in the 0-50-cm soil profile. However, similar patterns of SOC and TN concentrations were observed in the AF and CR treatments across the entire profile. The SOC stocks at 0-50-cm depth were 5.42, 5.52, and 4.67 kg m(-2) for CR, AF, and WO treatments, respectively. The calculated TN stocks at 0-50-cm depth were 0.63, 0.62, and 0.57 kg m(-2) for CR, AF, and WO treatments, respectively. This result demonstrated that the stocks of SOC and TN in WO were clearly lower than those of AF and CR and that the walnut-based agroforestry system was more beneficial than walnut monoculture in terms of SOC and TN sequestration. Owing to the short-term intercropping practice, the changes in SOC and TN stocks were slight in AF compared with those in CR. However, a significant decrease in SOC and TN stocks was observed during the conversion of cropland to walnut orchard after 7 years of management. We also found that land use types had no significant effect on soil C/N ratio. These findings demonstrated that intercropping between walnut rows can potentially maintain

  5. Observational Facts of Sustained Departure Plateau Vortexes

    Institute of Scientific and Technical Information of China (English)

    YU Shuhua; GAO Wenliang; PENG Jun; XIAO Yuhua

    2014-01-01

    By using the twice-daily atmospheric observation data from 1998 to 2012, station rainfall data, Tropical Rainfall Measure Mission (TRMM) data, as well as the plateau vortex and shear line year book, charac-teristics of the sustained departure plateau vortexes (SDPVs) are analyzed. Some new useful observational facts and understanding are obtained about the SDPV activities. The following results are obtained. (1) The active period of SDPVs is from June to August, most in July, unlike that of the unsustained depar-ture plateau vortexes (UDPVs), which have same occurrence frequencies in the three summer months. (2) The SDPVs, gen