The water of Bosten Lake was released to lower reaches of the Tarim River for 5 times from 2000 to 2002. The changes of total dissolved solid (TDS) and the major ions (SO2-4, Cl-, Na+, Ca2+, Mg2+ and HCO-3) were ana...The water of Bosten Lake was released to lower reaches of the Tarim River for 5 times from 2000 to 2002. The changes of total dissolved solid (TDS) and the major ions (SO2-4, Cl-, Na+, Ca2+, Mg2+ and HCO-3) were analyzed during this period. It was found out that TDS and the concentrations of the major ions initially and quickly increased and then decreased, but finally increased again. These changes were different at different distances from the river, which indicated that the groundwater changes relied on the distance from the river. In addition, the salt in groundwater was only diluted but not removed by the water. It was suggested that ecological measures should be sought to really promote the quality of the groundwater at the lower reaches of the Tarim River.展开更多
The Integrated Environmental Monitoring (IEM) project, part of the Asia-Pacific Environmental Innovation Strategy (APEIS) project, developed an integrated environmental monitoring system that can be used to detect, mo...The Integrated Environmental Monitoring (IEM) project, part of the Asia-Pacific Environmental Innovation Strategy (APEIS) project, developed an integrated environmental monitoring system that can be used to detect, monitor, and assess environmental disasters, degradation, and their impacts in the Asia-Pacific region. The system primarily employs data from the moderate resolution imaging spectrometer (MODIS) sensor on the Earth Observation System-(EOS-) Terra/Aqua satellite, as well as those from ground observations at five sites in different ecological systems in China. From the preliminary data analysis on both annual and daily variations of water, heat and CO2 fluxes, we can confirm that this system basically has been working well. The results show that both latent flux and CO2 flux are much greater in the crop field than those in the grassland and the saline desert, whereas the sensible heat flux shows the opposite trend. Different data products from MODIS have very different correspondence, e.g. MODIS-derived land surface temperature has a close correlation with measured ones, but LAI and NPP are quite different from ground measurements, which suggests that the algorithms used to process MODIS data need to be revised by using the local dataset. We are now using the APEIS-FLUX data to develop an integrated model, which can simulate the regional water, heat, and carbon fluxes. Finally, we are expected to use this model to develop more precise high-order MODIS products in Asia-Pacific region.展开更多
Based on the Tibet Autonomous Region's statistic yearbooks and the data fromthe two household surveys in 2002 and 2004, this paper has comprehensively analyzed the pattern ofchanges on the farmers and herdsmen'...Based on the Tibet Autonomous Region's statistic yearbooks and the data fromthe two household surveys in 2002 and 2004, this paper has comprehensively analyzed the pattern ofchanges on the farmers and herdsmen's income sources in the Tibet Autonomous Region since 1990 withthe main findings as follows; (1) The change of income from the labor payment is the fastest; (2)There is no regular pattern of income variation for the household economic activities, the farmersand herdsmen's household incomegeneration projects are impacted by the elements like prices andreturns, and there is a lack of appropriate direction; (3) The income structure of labor paymentshows that the income from the farmers and herdsmen working outside grows fastest; (4) The incomefrom the farmers and herdsmen's labor payment correlate positively to their net income per capita;(5) From the perspective of the variation by region, labor payment income has changed fastest in thecounties of Rutok, Nyerong and Khangmar comparedthe data from the household survey in 2002 withthat of 2004.展开更多
In this paper, taking railway flood in Xinjiang Line of New Eurasian Continental Bridge as an example, the dynamics mechanism of railway flood has been studied by using Chaotic Theory. During study, some nonlinear fea...In this paper, taking railway flood in Xinjiang Line of New Eurasian Continental Bridge as an example, the dynamics mechanism of railway flood has been studied by using Chaotic Theory. During study, some nonlinear features of railway flood, such as correlation dimension D2 and Kolomogorov entropy K, are analyzed based on time-series of railway flood in Xinjiang Line of New Eurasian Continental Bridge. Results show: time-series distribution of railway flood has some characteristics of Chaos dynamic system, and the variation of railway flood frequency is a definite low-dimension Chaotic attractor. The average length of Tp(Tp = 15d) calculated in this paper, which shows the time of forecasting by this Chaotic dynamic system, is close to the reality.展开更多
The biological soil crust serves as one of the biological factors contributing to the sand fixation in the Gurbantunggut Desert, the largest fixed and semi-fixed de- sert in China. This study was conducted to investig...The biological soil crust serves as one of the biological factors contributing to the sand fixation in the Gurbantunggut Desert, the largest fixed and semi-fixed de- sert in China. This study was conducted to investigate the microstructure and formation of biological soil crusts which develop as a result of occurrence of cryptogams. One year after removal of biological soil crusts, the exposed surface could be fixed by bacteria, which make sand particles cohere by exopolysaccharides. The exopolysaccharides were mainly composed of glucose, mannitol, arabinose and galactose. The intension of pressure for this kind of crust is 13.42±1.38 Pa. After four-year recovery of the exposed sandy surface, the biological soil crust resulting from the colonization of soil surface by communities of filamentous cyanobacteria were mainly dominated by Microcoleus, which occurred as a clus- ter of filaments surrounded by a gelatinous sheath. At this developmental stage, the main contributors for sand fixation were changed from bacteria to filamentous cyanobacteria. Microscopic examination of this kind of crust revealed an intricate network of filamentous cyanobacteria and ex- tracellular polymer secretions, which binds and entraps mineral particles and finer particles on the filament surface. These effects enhance soil cohesion and resistance to erosion. The intension of pressure for this kind of crust is 32.53±3.08 Pa.展开更多
The Snowmelt Runoff Model (SRM) is one of a very few models in the world today that requires remote sensing derived snow cover as model input. Owing to its simple data requirements and use of remote sensing to provide...The Snowmelt Runoff Model (SRM) is one of a very few models in the world today that requires remote sensing derived snow cover as model input. Owing to its simple data requirements and use of remote sensing to provide snow cover information, SRM is ideal for use in data sparse regions, particularly in remote and inaccessible high mountain watersheds. In order to verify the applicability of SRM in an environment of continental climate, a test of SRM is performed for the Gongnaisi River basin in the western Tianshan Mountains, the results show that two SRM average goodness-of-fit statistics for simulations, Nash-Sutcliff coefficient (R2) and volume difference (DV), are 0.87 and 0.90%, respectively. As compared with the application results over 80 basins in 25 different countries around the world, SRM performs well in the Gongnaisi River basin. The results also show that SRM can be a validated snowmelt runoff model capable of being applied in the western Tianshan Mountains. On the basis of snowmelt runoff simulation, together with a set of simplified hypothetical climate scenarios, SRM is also used to simulate the effects of climate change on snow cover and the consecutive snowmelt runoff. For a given hypothetical temperature increase of 4℃, the snow coverage and snowmelt season shift towards earlier dates, and the snowmelt runoff, as a result, is changed significantly at the same time. The simulation results show that the snow cover is sensitive to changes of climate, especially to the increase of temperature, the major effect of climate change will be a time shifting of snowmelt runoff to early spring months, resulting in a redistribution of seasonally runoff throughout the whole snowmelt season.展开更多
基金National Natural Science Foundation of China No.90102007+1 种基金 Knowledge Innovation Project of Chinese Academy of Sciences No.KZCX1-08-03
文摘The water of Bosten Lake was released to lower reaches of the Tarim River for 5 times from 2000 to 2002. The changes of total dissolved solid (TDS) and the major ions (SO2-4, Cl-, Na+, Ca2+, Mg2+ and HCO-3) were analyzed during this period. It was found out that TDS and the concentrations of the major ions initially and quickly increased and then decreased, but finally increased again. These changes were different at different distances from the river, which indicated that the groundwater changes relied on the distance from the river. In addition, the salt in groundwater was only diluted but not removed by the water. It was suggested that ecological measures should be sought to really promote the quality of the groundwater at the lower reaches of the Tarim River.
文摘The Integrated Environmental Monitoring (IEM) project, part of the Asia-Pacific Environmental Innovation Strategy (APEIS) project, developed an integrated environmental monitoring system that can be used to detect, monitor, and assess environmental disasters, degradation, and their impacts in the Asia-Pacific region. The system primarily employs data from the moderate resolution imaging spectrometer (MODIS) sensor on the Earth Observation System-(EOS-) Terra/Aqua satellite, as well as those from ground observations at five sites in different ecological systems in China. From the preliminary data analysis on both annual and daily variations of water, heat and CO2 fluxes, we can confirm that this system basically has been working well. The results show that both latent flux and CO2 flux are much greater in the crop field than those in the grassland and the saline desert, whereas the sensible heat flux shows the opposite trend. Different data products from MODIS have very different correspondence, e.g. MODIS-derived land surface temperature has a close correlation with measured ones, but LAI and NPP are quite different from ground measurements, which suggests that the algorithms used to process MODIS data need to be revised by using the local dataset. We are now using the APEIS-FLUX data to develop an integrated model, which can simulate the regional water, heat, and carbon fluxes. Finally, we are expected to use this model to develop more precise high-order MODIS products in Asia-Pacific region.
文摘Based on the Tibet Autonomous Region's statistic yearbooks and the data fromthe two household surveys in 2002 and 2004, this paper has comprehensively analyzed the pattern ofchanges on the farmers and herdsmen's income sources in the Tibet Autonomous Region since 1990 withthe main findings as follows; (1) The change of income from the labor payment is the fastest; (2)There is no regular pattern of income variation for the household economic activities, the farmersand herdsmen's household incomegeneration projects are impacted by the elements like prices andreturns, and there is a lack of appropriate direction; (3) The income structure of labor paymentshows that the income from the farmers and herdsmen working outside grows fastest; (4) The incomefrom the farmers and herdsmen's labor payment correlate positively to their net income per capita;(5) From the perspective of the variation by region, labor payment income has changed fastest in thecounties of Rutok, Nyerong and Khangmar comparedthe data from the household survey in 2002 withthat of 2004.
基金Supponed by world Bank Project (Disaster Reduction in china) (NoA3) and"Xibuzhiguang"Project(Prevention of Railway Flood in xinjiang Line of New Eurasian Continental Bridge)(98013010)
文摘In this paper, taking railway flood in Xinjiang Line of New Eurasian Continental Bridge as an example, the dynamics mechanism of railway flood has been studied by using Chaotic Theory. During study, some nonlinear features of railway flood, such as correlation dimension D2 and Kolomogorov entropy K, are analyzed based on time-series of railway flood in Xinjiang Line of New Eurasian Continental Bridge. Results show: time-series distribution of railway flood has some characteristics of Chaos dynamic system, and the variation of railway flood frequency is a definite low-dimension Chaotic attractor. The average length of Tp(Tp = 15d) calculated in this paper, which shows the time of forecasting by this Chaotic dynamic system, is close to the reality.
基金This work was supported by the National Natural Science Foundation of China(Grant No.90202019)Key Knowledge Innovation Project of the Chinese Acadermy of Sciences(Grant No.KZCX3-SW-343)the Research and Developmental Project for High Technique in Xinjiang Uygur Autonomous Region(Grant No.200415113).
文摘The biological soil crust serves as one of the biological factors contributing to the sand fixation in the Gurbantunggut Desert, the largest fixed and semi-fixed de- sert in China. This study was conducted to investigate the microstructure and formation of biological soil crusts which develop as a result of occurrence of cryptogams. One year after removal of biological soil crusts, the exposed surface could be fixed by bacteria, which make sand particles cohere by exopolysaccharides. The exopolysaccharides were mainly composed of glucose, mannitol, arabinose and galactose. The intension of pressure for this kind of crust is 13.42±1.38 Pa. After four-year recovery of the exposed sandy surface, the biological soil crust resulting from the colonization of soil surface by communities of filamentous cyanobacteria were mainly dominated by Microcoleus, which occurred as a clus- ter of filaments surrounded by a gelatinous sheath. At this developmental stage, the main contributors for sand fixation were changed from bacteria to filamentous cyanobacteria. Microscopic examination of this kind of crust revealed an intricate network of filamentous cyanobacteria and ex- tracellular polymer secretions, which binds and entraps mineral particles and finer particles on the filament surface. These effects enhance soil cohesion and resistance to erosion. The intension of pressure for this kind of crust is 32.53±3.08 Pa.
基金supported by the National Natural Science Foundation of China(Grand No.40235053)Resources&Ecological Environment Key Projects of the Chinese Academy of Sciences(Grant No.kz951-b1-213).
文摘The Snowmelt Runoff Model (SRM) is one of a very few models in the world today that requires remote sensing derived snow cover as model input. Owing to its simple data requirements and use of remote sensing to provide snow cover information, SRM is ideal for use in data sparse regions, particularly in remote and inaccessible high mountain watersheds. In order to verify the applicability of SRM in an environment of continental climate, a test of SRM is performed for the Gongnaisi River basin in the western Tianshan Mountains, the results show that two SRM average goodness-of-fit statistics for simulations, Nash-Sutcliff coefficient (R2) and volume difference (DV), are 0.87 and 0.90%, respectively. As compared with the application results over 80 basins in 25 different countries around the world, SRM performs well in the Gongnaisi River basin. The results also show that SRM can be a validated snowmelt runoff model capable of being applied in the western Tianshan Mountains. On the basis of snowmelt runoff simulation, together with a set of simplified hypothetical climate scenarios, SRM is also used to simulate the effects of climate change on snow cover and the consecutive snowmelt runoff. For a given hypothetical temperature increase of 4℃, the snow coverage and snowmelt season shift towards earlier dates, and the snowmelt runoff, as a result, is changed significantly at the same time. The simulation results show that the snow cover is sensitive to changes of climate, especially to the increase of temperature, the major effect of climate change will be a time shifting of snowmelt runoff to early spring months, resulting in a redistribution of seasonally runoff throughout the whole snowmelt season.