Oases in arid northwestern China play a significant role in the region's economic stability and development. Overex- ploitation of the region's water resources has led to serious environmental consequences. In oases...Oases in arid northwestern China play a significant role in the region's economic stability and development. Overex- ploitation of the region's water resources has led to serious environmental consequences. In oases, irrigated agriculture is the primary consumer of water, but water shortages resulting from dramatically growing human needs have become a bottleneck for regional sustainable development, making effective management of the limited available water critical. Effective strategies must be formulated to increase agricultural productivity while reducing its environmental impacts. To support the development of such strategies, water use patterns were analyzed during the 2007 and 2008 growing seasons, from May to early October, to identify opportunities for improving water management using the Mold- en-Sakthivadivel water-accounting method, which combines groundwater and surface water into a single domain and can provide a good estimate of the uses, depletion, and productivity of water in a water basin context. The study area lies in Linze County, Gansu Province, China. In the study area, the inflow water resources consist of irrigation, precipita- tion, and soil water, which accounted for 89.3%, 8.9%, and 1.8% of the total in 2007, and 89.3%, 4.8%, and 5.9% in 2008, respectively. The irrigation depends heavily on groundwater, which accounted for 82.1% and 83.6% of the total irrigation water in 2007 and 2008, respectively. In 2007 and 2008, deep percolation accounted for 50.1% and 47.9% of the water outflow, respectively, with corresponding depleted fractions of 0.51 and 0.55, respectively. For the irrigation district as a whole, the water productivity was only 1.37 CNY/m^3. To significantly increase crop water productivity and prevent depletion of the region's groundwater aquifer, it will be necessary to reduce the amount of water used for ir- rigation. Several water-saving agricultural practices are discussed and recommended.展开更多
The hydrological characteristics of the Heihe River Basin in the arid inland area of northwest China were investigated.The spatial distribution of annual precipitation in the basin indicates that it decreases from eas...The hydrological characteristics of the Heihe River Basin in the arid inland area of northwest China were investigated.The spatial distribution of annual precipitation in the basin indicates that it decreases from east to west and from south to north,and increases with elevation by a gradient of 24.4 mm per hundred meters below 2,810 m a.s.l.,but decreases with elevation by that of 37.0 mm per hundred meters above 2,810 m a.s.l.For the last 50 years,the mountain runoff of the ba-sin has a tendency of increase.Except in the mountain area,the aridity is very high in the basin,and the aridity index ranges from 1.6 to 7.0 at the piedmont,to 9.0~20.0 in the midstream area and up to 40.0 in the downstream Ejin region.It is estimated for the last 50 years that a 1oC increment of annual temperature causes a 21.5 mm increase of evaporation in the mountain area,and the equivalent reduction of mountain runoff is 0.215×109 m3/yr at the Yingluoxia Hydrometric Sta-tion.The estimation shows also that a 1oC increment of annual temperature causes 1,842 mm increase of farmland evapotranspiration in the midstream area,an equivalent of 0.298×109 m3/yr more water consumption.The anthropogenic influence on the hydrological processes and water resources is then discussed.展开更多
The increasing shortage in water resources is a key factor affecting sustainable socio-economic development in the arid region of Northwest China(ARNC). Water shortages also affect the stability of the region's oa...The increasing shortage in water resources is a key factor affecting sustainable socio-economic development in the arid region of Northwest China(ARNC). Water shortages also affect the stability of the region's oasis ecosystem. This paper summarizes the hydrological processes and water cycle of inland river basins in the ARNC, focusing on the following aspects: the spatial-temporal features of water resources(including air water vapor resources, runoff, and glacial meltwater) and their driving forces; the characteristics of streamflow composition in the inland river basins; the characteristics and main controlling factors of baseflow in the inland rivers; and anticipated future changes in hydrological processes and water resources. The results indicate that:(1) although the runoff in most inland rivers in the ARNC showed a significant increasing trend, both the glaciated area and glacial ice reserves have been reduced in the mountains;(2) snow melt and glacier melt are extremely important hydrological processes in the ARNC, especially in the Kunlun and Tianshan mountains;(3) baseflow in the inland rivers of the ARNC is the result of climate change and human activities, with the main driving factors being the reduction in forest area and the over-exploitation and utilization of groundwater in the river basins; and(4) the contradictions among water resources, ecology and economy will further increase in the future. The findings of this study might also help strengthen the ecological, economic and social sustainable development in the study region.展开更多
Water is a key restricting factor of the economic development and eco-environmental protection in arid inland river basins of Northwest China. Although water supplies are short, the water utilization structure and the...Water is a key restricting factor of the economic development and eco-environmental protection in arid inland river basins of Northwest China. Although water supplies are short, the water utilization structure and the corresponding industrial structure are unbalanced. We constructed a System Dynamic Model for mutual optimization based on the mechanism of their interaction. This model is applied to the Heihe River Basin where the share of limited water resources among ecosystem, production and human living is optimized. Results show that, by mutual optimization, the water utilization structure and the industrial structures fit in with each other. And the relationships between the upper, middle and lower reaches of the Heihe River Basin can be harmonized. Mutual benefits of ecology, society and economy can be reached, and a sustainable ecology-production-living system can be obtained. This study gives a new insight and method for the sustainable utilization of water resources in arid inland river basins.展开更多
Changes in rainfall extremes pose a serious and additional threat to water resources planning and management, natural and artificial oasis stability, and sustainable development in the fragile ecosystems of arid inlan...Changes in rainfall extremes pose a serious and additional threat to water resources planning and management, natural and artificial oasis stability, and sustainable development in the fragile ecosystems of arid inland river basins. In this study, the trend and temporal variation of extreme precipitation are analyzed using daily precipitation datasets at 11 stations over the arid inland Heihe River basin in Northwest China from 1960 to 2011. Eight indices of extreme precipitation are studied. The results show statistically significant and large-magnitude increasing and decreasing trends for most indices, primarily in the Qilian Mountains and eastern Hexi Corridor. More frequent and intense rainfall extremes have occurred in the southern part of the desert area than in the northern portion. In general, the temporal variation in precipitation extremes has changed throughout the basin. Wet day precipitation and heavy precipitation days show statistically significant linear increasing trends and step changes in the Qilian Mountains and Hexi Corridor. Consecutive dry days have decreased obviously in the region in most years after approximately the late 1980s, but meanwhile very long dry spells have increased, especially in the Hexi Corridor. The probability density function indicates that very long wet spells have increased in the Qilian Mountains. The East Asian summer monsoon index and western Pacific subtropical high intensity index possess strong and significant negative and positive correlations with rainfall extremes, respectively. Changes in land surface characteristics and the increase in water vapor in the wet season have also contributed to the changes in precipitation extremes over the river basin.展开更多
Water resources of inland river basins of arid Northwest China will be profoundly affected by future accelerated glacier melt. Based on scenarios of climate warming, accelerated glacier melt and socioeconomic developm...Water resources of inland river basins of arid Northwest China will be profoundly affected by future accelerated glacier melt. Based on scenarios of climate warming, accelerated glacier melt and socioeconomic development in the future, vulnerability of the Yarkent River Basin water resources for 2010-2030 is evaluated quantitatively using the indicator of water deficiency ratio. Results show that the quantity of the basin's water resources will continuously increase over the next 20 years, mainly due to the effect of climate warming and accelerated glacier melt. But, in the next 10 years, the basin will have a deficient water status, and the water resource system will be quite vulnerable. This is due to an increased water demand from rapidly increasing socioeco- nomic development and a lack of low water-use efficiency in the near future. After about 2020, water supply will outstrip demand, greatly relieving the basin's water deficient due to increased water resources and the advancement of water-saving technology. Contrast to the hypothetical situation of unchanged glacier melt, climate wanning and resulting accelerated glacier melt may play a role in relieving the supply-demand strain to some extent.展开更多
Studies indicate that the climate has experienced a dramatic change in the Heihe River Basin with scope of temperature rise reaching 0.5-1.1 o C in the 1990s compared to the mean value of the per...Studies indicate that the climate has experienced a dramatic change in the Heihe River Basin with scope of temperature rise reaching 0.5-1.1 o C in the 1990s compared to the mean value of the period 1960-1990, precipitation increased 18.5 mm in the 1990s compared to the 1950s, and 6.5 mm in the 1990s compared to the mean value of the period 1960-1990, water resources decreased 2.6×10 8 m 3 in the 1990s compared to the 1950s, and 0.4×10 8 m 3 in the 1990s compared to the mean value of the period 1960-1990. These changes have exerted a greater effect on the local environment and socio-economy, and also made the condition worsening in water resources utilizations in the Heihe Rver Basin.展开更多
Water shortage is a chronic problem in arid Northwest China.The rapid population growth and expanding urbanization as well as potential climate change impacts are likely to worsen the situation,threatening domestic,ir...Water shortage is a chronic problem in arid Northwest China.The rapid population growth and expanding urbanization as well as potential climate change impacts are likely to worsen the situation,threatening domestic,irrigation,and industrial supplies and even the survival of the ecosystems in Northwest China.This paper describes the preliminary work of adapting the Distributed Large Basin Runoff Model(DLBRM) to the Heihe watershed(the second largest inland river in arid Northwestern China,with a drainage area of 128,000 km2) for understanding distribution of glacial-snow melt,groundwater,surface runoff,and evapotranspi-ration,and for assessing hydrological impacts of climate change and glacial recession on water supply in the middle and lower reaches of the watershed.Preliminary simulation results show that the Qilian Mountain in the upper reach area produces most runoff in the Heihe watershed.The simulated daily river flows during the period of 1990-2000 indicate that the Heihe River dis-charges about 1×109 m3 of water from the middle reach(at Zhengyixia Station) to lower reach,with surface runoff and interflow contributing 51 and 49 percent respectively.The sandy lower soil zone in the middle reach has the highest evapotranspiration rate and also contributes nearly half of the river flow.Work underway focuses on the DLBRM model improvement and incorporation of the climate change and management scenarios to the hydrological simulations in the watershed.展开更多
Assessment of spatiotemporal characteristics of drought under climate change is significant for drought mitigation.In this study,the standardized precipitation evapotranspiration index(SPEI)calculated at different tim...Assessment of spatiotemporal characteristics of drought under climate change is significant for drought mitigation.In this study,the standardized precipitation evapotranspiration index(SPEI)calculated at different timescales was adopted to describe the drought conditions in the Heihe River Basin(HRB)from 1961 to 2014.The period characteristics and spatiotemporal distribution of drought were analyzed by using the extreme-point symmetric mode decomposition(ESMD)and inverse distance weight interpolation methods.Four main results were obtained.(1)The SPEI series of the upper reaches of the HRB at different timescales showed an upward trend(not significant)during 1961–2014.In the middle and lower reaches,the SPEI series exhibited significant downward trends.(2)The annual SPEI series of the lower reaches was decomposed through the ESMD method and exhibited a fluctuating downward trend as a whole.The oscillation showed quasi-3.4-year and quasi-4.5-year periods in the interannual variation,while a quasi-13.5-year period occurred in the interdecadal variation.The interannual period plays a leading role in drought variation across the HRB.(3)The entire research period was divided into three subperiods by the Bernaola–Galvan segmentation algorithm:1961–1966,1967–1996,and 1997–2014.The spring drought frequency and autumn drought intensity arrived at their maxima in the lower reaches during 1997–2014,with values of 72.22%and 1.56,respectively.The high frequency and intensity areas of spring,summer,and autumn drought moved from the middle-upper reaches to the middle-lower reaches of the HRB during 1961–2014.(4)Compared to the wavelet transform,the ESMD method has self-adaptability for signal decomposition and is more accurate for drought period analysis.Extreme-point symmetric mode decomposition is a more efficient decomposition method for nonlinear and nonstationary time series and has important significance for revealing the complicated change features of climate systems.展开更多
基金funded by the National Natural Science Foundation of China (Project 40771079 and 41471024)
文摘Oases in arid northwestern China play a significant role in the region's economic stability and development. Overex- ploitation of the region's water resources has led to serious environmental consequences. In oases, irrigated agriculture is the primary consumer of water, but water shortages resulting from dramatically growing human needs have become a bottleneck for regional sustainable development, making effective management of the limited available water critical. Effective strategies must be formulated to increase agricultural productivity while reducing its environmental impacts. To support the development of such strategies, water use patterns were analyzed during the 2007 and 2008 growing seasons, from May to early October, to identify opportunities for improving water management using the Mold- en-Sakthivadivel water-accounting method, which combines groundwater and surface water into a single domain and can provide a good estimate of the uses, depletion, and productivity of water in a water basin context. The study area lies in Linze County, Gansu Province, China. In the study area, the inflow water resources consist of irrigation, precipita- tion, and soil water, which accounted for 89.3%, 8.9%, and 1.8% of the total in 2007, and 89.3%, 4.8%, and 5.9% in 2008, respectively. The irrigation depends heavily on groundwater, which accounted for 82.1% and 83.6% of the total irrigation water in 2007 and 2008, respectively. In 2007 and 2008, deep percolation accounted for 50.1% and 47.9% of the water outflow, respectively, with corresponding depleted fractions of 0.51 and 0.55, respectively. For the irrigation district as a whole, the water productivity was only 1.37 CNY/m^3. To significantly increase crop water productivity and prevent depletion of the region's groundwater aquifer, it will be necessary to reduce the amount of water used for ir- rigation. Several water-saving agricultural practices are discussed and recommended.
基金supported by a grant from National Natural Sciences Foundation of China (No.40725001 No.40671010)+1 种基金the Key Project (KZCX2-XB2-04-02) of the Chinese Academy of Sciences,the National Key Technology R & D Program (No. 2007BAD46B01)
文摘The hydrological characteristics of the Heihe River Basin in the arid inland area of northwest China were investigated.The spatial distribution of annual precipitation in the basin indicates that it decreases from east to west and from south to north,and increases with elevation by a gradient of 24.4 mm per hundred meters below 2,810 m a.s.l.,but decreases with elevation by that of 37.0 mm per hundred meters above 2,810 m a.s.l.For the last 50 years,the mountain runoff of the ba-sin has a tendency of increase.Except in the mountain area,the aridity is very high in the basin,and the aridity index ranges from 1.6 to 7.0 at the piedmont,to 9.0~20.0 in the midstream area and up to 40.0 in the downstream Ejin region.It is estimated for the last 50 years that a 1oC increment of annual temperature causes a 21.5 mm increase of evaporation in the mountain area,and the equivalent reduction of mountain runoff is 0.215×109 m3/yr at the Yingluoxia Hydrometric Sta-tion.The estimation shows also that a 1oC increment of annual temperature causes 1,842 mm increase of farmland evapotranspiration in the midstream area,an equivalent of 0.298×109 m3/yr more water consumption.The anthropogenic influence on the hydrological processes and water resources is then discussed.
基金supported by the National Natural Science Foundation of China (41630859)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA19030204)
文摘The increasing shortage in water resources is a key factor affecting sustainable socio-economic development in the arid region of Northwest China(ARNC). Water shortages also affect the stability of the region's oasis ecosystem. This paper summarizes the hydrological processes and water cycle of inland river basins in the ARNC, focusing on the following aspects: the spatial-temporal features of water resources(including air water vapor resources, runoff, and glacial meltwater) and their driving forces; the characteristics of streamflow composition in the inland river basins; the characteristics and main controlling factors of baseflow in the inland rivers; and anticipated future changes in hydrological processes and water resources. The results indicate that:(1) although the runoff in most inland rivers in the ARNC showed a significant increasing trend, both the glaciated area and glacial ice reserves have been reduced in the mountains;(2) snow melt and glacier melt are extremely important hydrological processes in the ARNC, especially in the Kunlun and Tianshan mountains;(3) baseflow in the inland rivers of the ARNC is the result of climate change and human activities, with the main driving factors being the reduction in forest area and the over-exploitation and utilization of groundwater in the river basins; and(4) the contradictions among water resources, ecology and economy will further increase in the future. The findings of this study might also help strengthen the ecological, economic and social sustainable development in the study region.
基金Key Project of National Natural Science Foundation of China, No.40335049 National Natural Science Foundation of China, No.40471059
文摘Water is a key restricting factor of the economic development and eco-environmental protection in arid inland river basins of Northwest China. Although water supplies are short, the water utilization structure and the corresponding industrial structure are unbalanced. We constructed a System Dynamic Model for mutual optimization based on the mechanism of their interaction. This model is applied to the Heihe River Basin where the share of limited water resources among ecosystem, production and human living is optimized. Results show that, by mutual optimization, the water utilization structure and the industrial structures fit in with each other. And the relationships between the upper, middle and lower reaches of the Heihe River Basin can be harmonized. Mutual benefits of ecology, society and economy can be reached, and a sustainable ecology-production-living system can be obtained. This study gives a new insight and method for the sustainable utilization of water resources in arid inland river basins.
基金supported by the Key Project of the Chinese Academy of Sciences (Grant No.KZZDEW-04-05)supported by the Australia–China Joint Research Centre on River Basin Management
文摘Changes in rainfall extremes pose a serious and additional threat to water resources planning and management, natural and artificial oasis stability, and sustainable development in the fragile ecosystems of arid inland river basins. In this study, the trend and temporal variation of extreme precipitation are analyzed using daily precipitation datasets at 11 stations over the arid inland Heihe River basin in Northwest China from 1960 to 2011. Eight indices of extreme precipitation are studied. The results show statistically significant and large-magnitude increasing and decreasing trends for most indices, primarily in the Qilian Mountains and eastern Hexi Corridor. More frequent and intense rainfall extremes have occurred in the southern part of the desert area than in the northern portion. In general, the temporal variation in precipitation extremes has changed throughout the basin. Wet day precipitation and heavy precipitation days show statistically significant linear increasing trends and step changes in the Qilian Mountains and Hexi Corridor. Consecutive dry days have decreased obviously in the region in most years after approximately the late 1980s, but meanwhile very long dry spells have increased, especially in the Hexi Corridor. The probability density function indicates that very long wet spells have increased in the Qilian Mountains. The East Asian summer monsoon index and western Pacific subtropical high intensity index possess strong and significant negative and positive correlations with rainfall extremes, respectively. Changes in land surface characteristics and the increase in water vapor in the wet season have also contributed to the changes in precipitation extremes over the river basin.
基金supported by the Western Project Program of the Chinese Academy of Sciences(Nos.KZCX-XB2-04-04,KZCX2-XB2-09-6)
文摘Water resources of inland river basins of arid Northwest China will be profoundly affected by future accelerated glacier melt. Based on scenarios of climate warming, accelerated glacier melt and socioeconomic development in the future, vulnerability of the Yarkent River Basin water resources for 2010-2030 is evaluated quantitatively using the indicator of water deficiency ratio. Results show that the quantity of the basin's water resources will continuously increase over the next 20 years, mainly due to the effect of climate warming and accelerated glacier melt. But, in the next 10 years, the basin will have a deficient water status, and the water resource system will be quite vulnerable. This is due to an increased water demand from rapidly increasing socioeco- nomic development and a lack of low water-use efficiency in the near future. After about 2020, water supply will outstrip demand, greatly relieving the basin's water deficient due to increased water resources and the advancement of water-saving technology. Contrast to the hypothetical situation of unchanged glacier melt, climate wanning and resulting accelerated glacier melt may play a role in relieving the supply-demand strain to some extent.
基金National Natural Science Foundation of China , No.40235053 Knowledge Innovation Project of CAS+1 种基金 No.KZCX3-SW-329 No.KZCX1-10-03-01
文摘Studies indicate that the climate has experienced a dramatic change in the Heihe River Basin with scope of temperature rise reaching 0.5-1.1 o C in the 1990s compared to the mean value of the period 1960-1990, precipitation increased 18.5 mm in the 1990s compared to the 1950s, and 6.5 mm in the 1990s compared to the mean value of the period 1960-1990, water resources decreased 2.6×10 8 m 3 in the 1990s compared to the 1950s, and 0.4×10 8 m 3 in the 1990s compared to the mean value of the period 1960-1990. These changes have exerted a greater effect on the local environment and socio-economy, and also made the condition worsening in water resources utilizations in the Heihe Rver Basin.
基金support for this research is provided by the International Partnership Project of the Chinese Academy of Sciences, "The Basic Research for Water Issues of Inland River Basin in Arid Region" (CXTD-Z2005-2)Scherer Endowment Fund of Western Michigan University Department of Geography
文摘Water shortage is a chronic problem in arid Northwest China.The rapid population growth and expanding urbanization as well as potential climate change impacts are likely to worsen the situation,threatening domestic,irrigation,and industrial supplies and even the survival of the ecosystems in Northwest China.This paper describes the preliminary work of adapting the Distributed Large Basin Runoff Model(DLBRM) to the Heihe watershed(the second largest inland river in arid Northwestern China,with a drainage area of 128,000 km2) for understanding distribution of glacial-snow melt,groundwater,surface runoff,and evapotranspi-ration,and for assessing hydrological impacts of climate change and glacial recession on water supply in the middle and lower reaches of the watershed.Preliminary simulation results show that the Qilian Mountain in the upper reach area produces most runoff in the Heihe watershed.The simulated daily river flows during the period of 1990-2000 indicate that the Heihe River dis-charges about 1×109 m3 of water from the middle reach(at Zhengyixia Station) to lower reach,with surface runoff and interflow contributing 51 and 49 percent respectively.The sandy lower soil zone in the middle reach has the highest evapotranspiration rate and also contributes nearly half of the river flow.Work underway focuses on the DLBRM model improvement and incorporation of the climate change and management scenarios to the hydrological simulations in the watershed.
基金the grant support from the National Natural Science Foundation of China(51879222 and 91425302)the National Key Research and Development Program during the 13th Five-Year Plan in China(2016YFC0401306).
文摘Assessment of spatiotemporal characteristics of drought under climate change is significant for drought mitigation.In this study,the standardized precipitation evapotranspiration index(SPEI)calculated at different timescales was adopted to describe the drought conditions in the Heihe River Basin(HRB)from 1961 to 2014.The period characteristics and spatiotemporal distribution of drought were analyzed by using the extreme-point symmetric mode decomposition(ESMD)and inverse distance weight interpolation methods.Four main results were obtained.(1)The SPEI series of the upper reaches of the HRB at different timescales showed an upward trend(not significant)during 1961–2014.In the middle and lower reaches,the SPEI series exhibited significant downward trends.(2)The annual SPEI series of the lower reaches was decomposed through the ESMD method and exhibited a fluctuating downward trend as a whole.The oscillation showed quasi-3.4-year and quasi-4.5-year periods in the interannual variation,while a quasi-13.5-year period occurred in the interdecadal variation.The interannual period plays a leading role in drought variation across the HRB.(3)The entire research period was divided into three subperiods by the Bernaola–Galvan segmentation algorithm:1961–1966,1967–1996,and 1997–2014.The spring drought frequency and autumn drought intensity arrived at their maxima in the lower reaches during 1997–2014,with values of 72.22%and 1.56,respectively.The high frequency and intensity areas of spring,summer,and autumn drought moved from the middle-upper reaches to the middle-lower reaches of the HRB during 1961–2014.(4)Compared to the wavelet transform,the ESMD method has self-adaptability for signal decomposition and is more accurate for drought period analysis.Extreme-point symmetric mode decomposition is a more efficient decomposition method for nonlinear and nonstationary time series and has important significance for revealing the complicated change features of climate systems.
文摘利用1998-2008年56个气象台站降水资料,结合TRMM月降水产品,通过对TRMM3B43降水数据在不同气候区、不同时空尺度的精度对比分析,探讨了卫星遥感反演降水产品在中国西北内陆河流域的适应性.结果表明:TRMM探测的月降水数据与实测月降水数据在整体上具有较好的一致性和线性相关性,相关系数为0.76,效率系数为0.58,其探测的降水量比观测值略大;TRMM在高原气候区月降水量的探测效果要优于在西风带区的;TRMM数据所反映的降水量的年内变化过程和实测降水量结果基本一致,但在具体的量上有一定的差异,表现为对降水相对集中的5-9月低估实测降水量,而在降水较少的10月-次年4月高估实测降水量,反映了TRMM对较大强度降水量的探测能力不足.流域多年平均降水量呈现南、北部大,中部小的格局,降水量的高值中心主要出现在高山地区,高达300 mm;而受西风环流影响的塔里木盆地东南面的且末-若羌一带、吐鲁番盆地和受高原区影响的柴达木盆地为极端干旱少雨区,降水量均不足100 mm.