This paper, based on the analysis and calculation of the groundwater resources in an arid region from 1980 to 2001, put forward the concept of ecological groundwater level threshold for either salinity control or the ...This paper, based on the analysis and calculation of the groundwater resources in an arid region from 1980 to 2001, put forward the concept of ecological groundwater level threshold for either salinity control or the determination of ecological warning. The surveys suggest that soil moisture and soil salinity are the most important environmental factors in determining the distribution and changes in vegetation. The groundwater level threshold of ecological warning can be determined by using a network of groundwater depth observation sites that monitor the environmental moisture gradient as reflected by plant physiological characteristics. According to long-term field observations within the Ejin oases, the groundwater level threshold for salinity control varied between 0.5 m and 1.5 m, and the ecological warning threshold varied between 3.5 m and 4.0 m. The quantity of groundwater re- sources （renewable water resources, ecological water resources, and exploitable water resources） in arid areas can be calculated from regional groundwater level information, without localized hydrogeological data. The concept of groundwater level threshold of ecological warning was established according to water development and water re- sources supply, and available groundwater resources were calculated. The concept not only enriches and broadens the content of groundwater studies, but also helps in predicting the prospects for water resources development.展开更多
Assessment of ecological flow or water level for water bodies is important for the protection of de- graded or degrading ecosystems caused by water shortage in arid regions, and it has become a key issue in water reso...Assessment of ecological flow or water level for water bodies is important for the protection of de- graded or degrading ecosystems caused by water shortage in arid regions, and it has become a key issue in water resources planning. In the past several decades, many methods have been proposed to assess ecological flow for rivers and ecological water level for lakes or wetlands. To balance water uses by human and ecosystems, we proposed a general multi-objective programming model to determine minimum ecological flow or water level for inland water bodies, where two objectives are water index for human and habitat index for ecosystems, respectively Using the weighted sum method for multi-objective optimization, minimum ecological flow or water level can be determined from the breakpoint in the water index-habitat index curve, which is similar to the slope method to de- termine minimum ecological flow from wetted perimeter-discharge curve. However, the general multi-objective programming model is superior to the slope method in its physical meaning and calculation method. This model provides a general analysis method for ecological water uses of different inland water bodies, and can be used to define minimum ecological flow or water level by choosing appropriate water and habitat indices. Several com- monly used flow or water level assessment methods were found to be special cases of the general model, including the wetted perimeter method and the multi-objective physical habitat simulation method for ecological river flow, the inundated forest width method for regeneration flow of floodplain forest and the lake surface area method for eco- logical lake level. These methods were applied to determine minimum ecological flow or water level for two repre- sentative rivers and a lake in northern Xinjiang of China, including minimum ecological flow for the Ertix River, minimum regeneration flow for floodplain forest along the midstream of Kaxgar River, and minimum ecological lake level for the Ebinur Lake. The results illustrated the versatility of the general model, and can provide references for water resources planning and ecosystem protection for these rivers and lake.展开更多
Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other h...Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other human needs.The desiccation of lakes leads to severe environmental,economic,and social repercussions.Urmia Lake,located in northwestern Iran and representing a vital natural ecosystem,has experienced a volume reduction of over 90.0%.Our research evaluated diverse water management strategies within the Urmia Lake basin and prospects of inter-basin water transfers.This study focused on strategies to safeguard the environmental water rights of the Urmia Lake by utilizing the modeling and simulating(MODSIM)model.The model simulated changes in the lake's water volume under various scenarios.These included diverting water from incoming rivers,cutting agricultural water use by 40.0%,releasing dam water in non-agricultural seasons,treated wastewater utilization,and inter-basin transfers.Analytical hierarchy process(AHP)was utilized to analyze the simulation results.Expert opinions with AHP analysis,acted as a multi-criteria decision-making tool to evaluate the simulation and determine the optimal water supply source priority for the Urmia Lake.Our findings underscore the critical importance of reducing agricultural water consumption as the foremost step in preserving the lake.Following this,inter-basin water transfers are suggested,with a detailed consideration of the inherent challenges and limitations faced by the source watersheds.It is imperative to conduct assessments on the impacts of these transfers on the downstream users and the potential environmental risks,advocating for a diplomatic and cooperative approach with adjacent country.This study also aims to forecast the volumes of water that can be transferred under different climatic conditions—drought,normal,and wet years—to inform strategic water management planning for the Urmia Lake.According to our projection,implementing the strategic scenarios outlined could significantly augment the lake's level and volume,potentially by 3.57×109–9.38×109 m3 over the coming 10 a and 3.57×109–10.70×109 m3 in the subsequent 15 a.展开更多
From the analysis on the problem of selection, data acquisition, quantification and accuracy check in the indicators to desertification degree both at home and abroad, one might conclude that in the existing assessmen...From the analysis on the problem of selection, data acquisition, quantification and accuracy check in the indicators to desertification degree both at home and abroad, one might conclude that in the existing assessment of desertification degree there is a prevailing tendency which is the substitution of absolute landscape for relative land degradation, namely, assessment of desertification degree is that of absolute landscape state to some extent. As a result the reassessment accuracy of desertification scope, damaging degree and control effect are affected. The regaining and establishment of the initial and final ecological datum level of land degradation are the prerequisite to the establishment of normal scientific indicator system. From the viewpoint of this three design principles of indicators to the desertification degree are put forward: the zonal principle of indicator systems decided by the ecological datum level corresponding to their bioclimatic zones, the hierarchical principle of indicator systems decided by different spatial scales and the resolutions of different sensors and principle of landscape types based on the 3S as core-indicator.展开更多
As a key component of the water cycle in arid regions,inland lakes have relatively fragile biological and ecological systems.Once the environment deteriorates,inland lakes in arid regions will be the first to respond ...As a key component of the water cycle in arid regions,inland lakes have relatively fragile biological and ecological systems.Once the environment deteriorates,inland lakes in arid regions will be the first to respond accordingly.In view of the lack of ecological water quantity,the continuous decline of lake water level and the insufficient carrying capacity of water resources caused by the changes in precipitation and evaporation,the construction of water replenishment projects and domestic water use for industrial and agricultural production in the inland lake basin in the arid region of China in recent years,the analysis and prediction of the minimum ecological lake water level were carried out.Taking Chenghai Lake as the case study,a comprehensive analysis of the historical water level evolution was conducted using the lowest annual average water level method,the natural water level data method,and the lake morphology data method,and got the current lowest ecological water level of Chenghai Lake was found to be 1495.43 m.And then,taking the year when the legal minimum water level is restored as the boundary for the future,the minimum ecological water level of Chenghai Lake was calculated to be 1499.20m.On this basis,combined with the water replenishment of the existing and under-construction diversion projects in Chenghai Lake,it is predicted that the year when Chenghai Lake will restore its legal minimum ecological water level will be 2025.The research will provide data support and a basis for decision-making for ecosystem restoration,lake area governance and protection,rational development,and utilization of watershed water resources in inland lakes.展开更多
The problem of land ecological security directly threatens the sustainable development of many regions,and exploring the spatio-temporal characteristics of land ecological security is helpful for analyzing the land ec...The problem of land ecological security directly threatens the sustainable development of many regions,and exploring the spatio-temporal characteristics of land ecological security is helpful for analyzing the land ecological patterns between regions and over time.Based on the interpretation of remote sensing image data for Tianjin in 1980,2000,2010 and 2019,supported by software such as ArcGIS and GeoDa,the changes of land use in the study area are calculated by using the land use dynamic degree.Then,the land ecological security index and spatial autocorrelation analysis methods are used to study the spatial correlations and internal heterogeneity of land ecological security in each district in Tianjin.The results show that:(1)The land use of Tianjin has changed dramatically in the past 40 years:the building land has been expanding,while the farmland and barren have been shrinking continuously.(2)The overall level of land ecological security is in the high security area,and Jizhou District is the highest,while the Central areas and Binhai are low.(3)The spatial heterogeneity of land ecological security is not obvious,but the spatial agglomeration is strong.展开更多
In recent years,the hydrological characters of Baiyangdian Wetland have changed greatly,which,in turn,influence the biotic component,the structure and function of the wetland ecosystem.In order to determine the demand...In recent years,the hydrological characters of Baiyangdian Wetland have changed greatly,which,in turn,influence the biotic component,the structure and function of the wetland ecosystem.In order to determine the demands for water resources of ecological wetland system,a method of ecological water level coefficient was suggested to calculate the water resources demands for wetland environment use.This research showed that the minimum coefficient is 0.94 and the optimal coefficient is more than 1.10.According to these two coefficients,the ecological water level and water quantity can be estimated.The results indicate that the amount of the minimal and optimal eco-environmental water require-ments are 0.87×10^(8) and 2.78×10^(8)m^(3) in average monthly,respectively,with the maximum eco-environmental water requirement in summer and the minimum in winter.The annual change of eco-environment water demand is in accord-ing with the climate change and hydrological characters.The method of ecological water level emphasizes that wetland ecosystem adapts to the hydrological conditions,so it can be used in practice well.展开更多
Asymmetric seasonal warming,characterized by more pronounced temperature increases in winter than in summer,has become a critical feature of global warming,especially in cold and high-altitude regions.Previous studies...Asymmetric seasonal warming,characterized by more pronounced temperature increases in winter than in summer,has become a critical feature of global warming,especially in cold and high-altitude regions.Previous studies have primarily focused on year-round warming,while comparatively less attention was paid to winter warming.However,a significant knowledge gap exists regarding the impacts of winter warming on ecosystem functions.To address this,we conducted an 8-year manipulated warming experiment in an alpine grassland on the Tibetan Plateau,employing three treatments:no warming,year-round warming and winter warming.We found that neither year-round warming nor winter warming significantly alters species richness at the community level.Notably,community biomass stability was maintained via species asynchrony.However,warming exerted significant effects on the plant abundance groups(dominant,common and rare species).Specifically,winter warming enhanced the stability of dominant species by increasing species asynchrony of dominant species,as the compensatory dynamics occurred between the grass and forbs.In contrast,year-round warming reduced the stability of common species,correlated with an increase in species richness and a decline in asynchrony among common species.Thus,our study underscores the capacity of alpine grassland to maintain community biomass stability via asynchrony dynamics of species under different warming conditions,although the stability of different abundance groups would be changed.Importantly,our results provide valuable insights for understanding the alpine grassland ecosystem on the Tibetan Plateau.展开更多
基金funded by the National Natural Science Foundation of China(9102500230970492)+2 种基金the Fundamental Research Funds for the Central Universities(GK201101002)the Key Project of the Chinese Academy of Sciences(KZZDEW-04-05)the National Key Technology R & D Program(2012BAC08B05)
文摘This paper, based on the analysis and calculation of the groundwater resources in an arid region from 1980 to 2001, put forward the concept of ecological groundwater level threshold for either salinity control or the determination of ecological warning. The surveys suggest that soil moisture and soil salinity are the most important environmental factors in determining the distribution and changes in vegetation. The groundwater level threshold of ecological warning can be determined by using a network of groundwater depth observation sites that monitor the environmental moisture gradient as reflected by plant physiological characteristics. According to long-term field observations within the Ejin oases, the groundwater level threshold for salinity control varied between 0.5 m and 1.5 m, and the ecological warning threshold varied between 3.5 m and 4.0 m. The quantity of groundwater re- sources （renewable water resources, ecological water resources, and exploitable water resources） in arid areas can be calculated from regional groundwater level information, without localized hydrogeological data. The concept of groundwater level threshold of ecological warning was established according to water development and water re- sources supply, and available groundwater resources were calculated. The concept not only enriches and broadens the content of groundwater studies, but also helps in predicting the prospects for water resources development.
基金supported by the Open Research Fund Program of State key Laboratory of Hydroscience and Engineering, Tsinghua University (sklhse-2013-A-03)the National Natural Science Foundation of China (50879041)
文摘Assessment of ecological flow or water level for water bodies is important for the protection of de- graded or degrading ecosystems caused by water shortage in arid regions, and it has become a key issue in water resources planning. In the past several decades, many methods have been proposed to assess ecological flow for rivers and ecological water level for lakes or wetlands. To balance water uses by human and ecosystems, we proposed a general multi-objective programming model to determine minimum ecological flow or water level for inland water bodies, where two objectives are water index for human and habitat index for ecosystems, respectively Using the weighted sum method for multi-objective optimization, minimum ecological flow or water level can be determined from the breakpoint in the water index-habitat index curve, which is similar to the slope method to de- termine minimum ecological flow from wetted perimeter-discharge curve. However, the general multi-objective programming model is superior to the slope method in its physical meaning and calculation method. This model provides a general analysis method for ecological water uses of different inland water bodies, and can be used to define minimum ecological flow or water level by choosing appropriate water and habitat indices. Several com- monly used flow or water level assessment methods were found to be special cases of the general model, including the wetted perimeter method and the multi-objective physical habitat simulation method for ecological river flow, the inundated forest width method for regeneration flow of floodplain forest and the lake surface area method for eco- logical lake level. These methods were applied to determine minimum ecological flow or water level for two repre- sentative rivers and a lake in northern Xinjiang of China, including minimum ecological flow for the Ertix River, minimum regeneration flow for floodplain forest along the midstream of Kaxgar River, and minimum ecological lake level for the Ebinur Lake. The results illustrated the versatility of the general model, and can provide references for water resources planning and ecosystem protection for these rivers and lake.
文摘Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other human needs.The desiccation of lakes leads to severe environmental,economic,and social repercussions.Urmia Lake,located in northwestern Iran and representing a vital natural ecosystem,has experienced a volume reduction of over 90.0%.Our research evaluated diverse water management strategies within the Urmia Lake basin and prospects of inter-basin water transfers.This study focused on strategies to safeguard the environmental water rights of the Urmia Lake by utilizing the modeling and simulating(MODSIM)model.The model simulated changes in the lake's water volume under various scenarios.These included diverting water from incoming rivers,cutting agricultural water use by 40.0%,releasing dam water in non-agricultural seasons,treated wastewater utilization,and inter-basin transfers.Analytical hierarchy process(AHP)was utilized to analyze the simulation results.Expert opinions with AHP analysis,acted as a multi-criteria decision-making tool to evaluate the simulation and determine the optimal water supply source priority for the Urmia Lake.Our findings underscore the critical importance of reducing agricultural water consumption as the foremost step in preserving the lake.Following this,inter-basin water transfers are suggested,with a detailed consideration of the inherent challenges and limitations faced by the source watersheds.It is imperative to conduct assessments on the impacts of these transfers on the downstream users and the potential environmental risks,advocating for a diplomatic and cooperative approach with adjacent country.This study also aims to forecast the volumes of water that can be transferred under different climatic conditions—drought,normal,and wet years—to inform strategic water management planning for the Urmia Lake.According to our projection,implementing the strategic scenarios outlined could significantly augment the lake's level and volume,potentially by 3.57×109–9.38×109 m3 over the coming 10 a and 3.57×109–10.70×109 m3 in the subsequent 15 a.
基金Under the auspices of the National Natural Science Foundation of China (49771009) and the Guangdong Provincial Key Research Proj
文摘From the analysis on the problem of selection, data acquisition, quantification and accuracy check in the indicators to desertification degree both at home and abroad, one might conclude that in the existing assessment of desertification degree there is a prevailing tendency which is the substitution of absolute landscape for relative land degradation, namely, assessment of desertification degree is that of absolute landscape state to some extent. As a result the reassessment accuracy of desertification scope, damaging degree and control effect are affected. The regaining and establishment of the initial and final ecological datum level of land degradation are the prerequisite to the establishment of normal scientific indicator system. From the viewpoint of this three design principles of indicators to the desertification degree are put forward: the zonal principle of indicator systems decided by the ecological datum level corresponding to their bioclimatic zones, the hierarchical principle of indicator systems decided by different spatial scales and the resolutions of different sensors and principle of landscape types based on the 3S as core-indicator.
基金Supported by the Jilin Electric Power Scientific Research Institute Co.Ltd.Science and Technology Project Funding under contract Nos 2023JBGS-08:Research on Intelligent Flood Risk Warning Technology for Power Grid Equipmentthe Open Research Fund of National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety under contract Nos GJGCZX-JJ-202422+11 种基金Open Research Fund of National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety under contract Nos GJGCZX-JJ-202422Hubei Key Laboratory of Hydropower Construction and Management(China Three Gorges University)Open Research Fund under contract Nos 2024KSD20China Three Gorges University Science Fund under contract Nos 2024KTZB04Ministry of Water Resources Major Science and Technology Project under contract Nos SKS-2022003the Open Research Fund of Key Laboratory of Sediment Science and Northern River Training,the Ministry of Water Resources,China Institute of Water Resources and Hydropower Research under contract Nos IWHR-SEDI-2023-07the National Natural Science Foundation of China under contract Nos 52009079National Key Research and Development Plan of China under contract Nos 2024YFD1702001Research and Cultivation Project for Postgraduate Teaching Reform of Three Gorges University under contract Nos SDYJ202312Three Gorges University Postgraduate Course Construction Project under contract Nos SDKC202402Three Gorges University Postgraduate Course Ideology and Political Research Project under contract Nos SDKCSZ202414Ministry of Education Industry-University Cooperative Education Project under contract Nos 230902313162259Ministry of Education Supply and Demand Matching Employment and Education Project under contract Nos 2024010998396.
文摘As a key component of the water cycle in arid regions,inland lakes have relatively fragile biological and ecological systems.Once the environment deteriorates,inland lakes in arid regions will be the first to respond accordingly.In view of the lack of ecological water quantity,the continuous decline of lake water level and the insufficient carrying capacity of water resources caused by the changes in precipitation and evaporation,the construction of water replenishment projects and domestic water use for industrial and agricultural production in the inland lake basin in the arid region of China in recent years,the analysis and prediction of the minimum ecological lake water level were carried out.Taking Chenghai Lake as the case study,a comprehensive analysis of the historical water level evolution was conducted using the lowest annual average water level method,the natural water level data method,and the lake morphology data method,and got the current lowest ecological water level of Chenghai Lake was found to be 1495.43 m.And then,taking the year when the legal minimum water level is restored as the boundary for the future,the minimum ecological water level of Chenghai Lake was calculated to be 1499.20m.On this basis,combined with the water replenishment of the existing and under-construction diversion projects in Chenghai Lake,it is predicted that the year when Chenghai Lake will restore its legal minimum ecological water level will be 2025.The research will provide data support and a basis for decision-making for ecosystem restoration,lake area governance and protection,rational development,and utilization of watershed water resources in inland lakes.
基金Tianjin Art and Science Planning Project(D16007)。
文摘The problem of land ecological security directly threatens the sustainable development of many regions,and exploring the spatio-temporal characteristics of land ecological security is helpful for analyzing the land ecological patterns between regions and over time.Based on the interpretation of remote sensing image data for Tianjin in 1980,2000,2010 and 2019,supported by software such as ArcGIS and GeoDa,the changes of land use in the study area are calculated by using the land use dynamic degree.Then,the land ecological security index and spatial autocorrelation analysis methods are used to study the spatial correlations and internal heterogeneity of land ecological security in each district in Tianjin.The results show that:(1)The land use of Tianjin has changed dramatically in the past 40 years:the building land has been expanding,while the farmland and barren have been shrinking continuously.(2)The overall level of land ecological security is in the high security area,and Jizhou District is the highest,while the Central areas and Binhai are low.(3)The spatial heterogeneity of land ecological security is not obvious,but the spatial agglomeration is strong.
基金This study was supported by the National Key Basic Research Development(973)Program of China(Grant No.2006CB403303)the National Natural Science Foundation of China(Grant No.50625926).
文摘In recent years,the hydrological characters of Baiyangdian Wetland have changed greatly,which,in turn,influence the biotic component,the structure and function of the wetland ecosystem.In order to determine the demands for water resources of ecological wetland system,a method of ecological water level coefficient was suggested to calculate the water resources demands for wetland environment use.This research showed that the minimum coefficient is 0.94 and the optimal coefficient is more than 1.10.According to these two coefficients,the ecological water level and water quantity can be estimated.The results indicate that the amount of the minimal and optimal eco-environmental water require-ments are 0.87×10^(8) and 2.78×10^(8)m^(3) in average monthly,respectively,with the maximum eco-environmental water requirement in summer and the minimum in winter.The annual change of eco-environment water demand is in accord-ing with the climate change and hydrological characters.The method of ecological water level emphasizes that wetland ecosystem adapts to the hydrological conditions,so it can be used in practice well.
基金the National Natural Science Foundation of China(U20A2009,41991234,42077422 and 41725003)the National Key Research and Development Program of China(2022YFF1301801)the Major Science and Technology Projects in Tibet(XZ202101ZD0007G and XZ202101ZD0003N).
文摘Asymmetric seasonal warming,characterized by more pronounced temperature increases in winter than in summer,has become a critical feature of global warming,especially in cold and high-altitude regions.Previous studies have primarily focused on year-round warming,while comparatively less attention was paid to winter warming.However,a significant knowledge gap exists regarding the impacts of winter warming on ecosystem functions.To address this,we conducted an 8-year manipulated warming experiment in an alpine grassland on the Tibetan Plateau,employing three treatments:no warming,year-round warming and winter warming.We found that neither year-round warming nor winter warming significantly alters species richness at the community level.Notably,community biomass stability was maintained via species asynchrony.However,warming exerted significant effects on the plant abundance groups(dominant,common and rare species).Specifically,winter warming enhanced the stability of dominant species by increasing species asynchrony of dominant species,as the compensatory dynamics occurred between the grass and forbs.In contrast,year-round warming reduced the stability of common species,correlated with an increase in species richness and a decline in asynchrony among common species.Thus,our study underscores the capacity of alpine grassland to maintain community biomass stability via asynchrony dynamics of species under different warming conditions,although the stability of different abundance groups would be changed.Importantly,our results provide valuable insights for understanding the alpine grassland ecosystem on the Tibetan Plateau.
