Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake B...Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake Basin in Xinjiang,Northwest China.In this paper,variations of runoff,temperature,precipitation,reference evapotranspiration,lake area,socio-economic water usage,groundwater level and water quality in the Ebinur Lake Basin from 1961 to 2015 were systematically analyzed by the Mann-Kendall test methods(M-K)mutation test,the cumulative levelling method,the climate-sensitive method and land-use change index.In addition,we evaluated the effects of human activities on land use change and water quality.The results reveal that there was a significant increase in temperature and precipitation from 1961 to 2015,despite a decrease in reference evapotranspiration.The Wenquan station was not significantly affected by human activities as it is situated at a higher altitude.Runoff at this station increased significantly with climate warming.In contrast,runoff at the Jinghe station was severely affected by numerous human activities.Runoff decreased without obvious fluctuations.The contributions of climate change to runoff variation at the Jinghe and Wenquan stations were 46.87%and 58.94%,respectively;and the contributions of human activities were 53.13%and 41.06%,respectively.Land-use patterns in the basin have changed significantly between 1990 and 2015:urban and rural constructed lands,saline-alkali land,bare land,cultivated land,and forest land have expanded,while areas under grassland,lake,ice/snow and river/channel have declined.Human activities have dramatically intensified land degradation and desertification.From 1961 to 2015,both the inflow into the Ebinur Lake and the area of the lake have declined year by year;groundwater levels have dropped significantly,and the water quality has deteriorated during the study period.In the oasis irrigation area below the runoff pass,human activities mainly influenced the utilization mode and quantity of water resources.Changes in the hydrology and quantity of water resources were driven primarily by the continuous expansion of cultivated land and oasis,as well as the growth of population and the construction of hydraulic engineering projects.After 2015,the effects of some ecological protection projects were observed.However,there was no obvious sign of ecological improvement in the basin,and some environmental problems continue to persist.On this basis,this study recommends that the expansion of oasis should be limited according to the carrying capacity of the local water bodies.Moreover,in order to ensure the ecological security of the basin,it is necessary to determine the optimal oasis area for sustainable development and improve the efficiency of water resources exploitation and utilization.展开更多
There is a lack of research on soil microplastics in arid oases considering the rapid economic development of northwestern China.Here,we studied the occurrence and sources of microplastics in soil,as well as the relat...There is a lack of research on soil microplastics in arid oases considering the rapid economic development of northwestern China.Here,we studied the occurrence and sources of microplastics in soil,as well as the relationships between microplastics and adsorbed heavy metals in the Ebinur Lake Basin,a typical arid oasis in China.Results showed that(1)the average microplastic content in all soil samples was 36.15(±3.27)mg/kg.The contents of microplastics at different sampling sites ranged from 3.89(±1.64)to 89.25(±2.98)mg/kg.Overall,the proportions of various microplastic shapes decreased in the following order:film(54.25%)>fiber(18.56%)>particle(15.07%)>fragment(8.66%)>foam(3.46%);(2)among all microplastic particles,white particles accounted for the largest proportion(52.93%),followed by green(24.15%),black(12.17%),transparent(7.16%),and yellow particles(3.59%).The proportions of microplastic particle size ranges across all soil samples decreased in the following order:1000-2000μm(40.88%)>500-1000μm(26.75%)>2000-5000μm(12.30%)>100-500μm(12.92%)>0-100μm(7.15%).FTIR(Fourier transform infrared)analyses showed that polyethylene terephthalate(PET),polypropylene(PP),polycarbonate(PC),polyethylene(PE),and polystyrene(PS)occurred in the studied soil;(3)random forest predictions showed that industrial and agricultural production activities and the discharge of domestic plastic waste were related to soil microplastic pollution,in which agricultural plastic film was the most important factor in soil pollution in the study area;and(4)seven heavy metals extracted from microplastics in the soil samples showed significant positive correlations with soil pH,EC,total salt,N,P,and K contents(P<0.01),indicating that these soil factors could significantly affect the contents of heavy metals carried by soil microplastics.This research demonstrated that the contents of soil microplastics are lower than other areas of the world,and they mainly come from industrial and agricultural activities of the Ebinur Lake Basin.展开更多
In arid and semi-arid environments,desert vegetation plays an important role in preventing soil erosion by wind and helps maintain the stability of desert and oasis ecosystems.Four types of typical desert vegetation,n...In arid and semi-arid environments,desert vegetation plays an important role in preventing soil erosion by wind and helps maintain the stability of desert and oasis ecosystems.Four types of typical desert vegetation,namely Populus euphratica,Haloxylon ammodendron,Nitraria sibirica,and Halostachs caspica,corresponding to different habitats(i.e.,river bank,sand dune,desert,and salt marsh)were chosen as the model vegetation in this research.Theδ^(2)H andδ^(18)O for rainwater,soil water,and plant water were applied to identify the water sources and quantify the proportions of different water sources used over the entire plant growth period(from March to October).The results showed that the precipitationδ^(2)H andδ^(18)O in the Ebinur Lake basin varied from-142.5‰to-0.6‰and from-20.16‰to 1.20‰,respectively.The largestδ^(2)H andδ^(18)O values occurred in summer and the smallest in winter.The soil waterδ^(2)H andδ^(18)O of the four habitats decreased gradually with increasing depth.Theδ^(2)H andδ^(18)O values of water extracted from the stems of the four plants had similar variation trends,that is,the maximum was observed in spring and the minimum in summer.Among the four plants,H.caspica had the highest stable isotopic values in the stem water,followed by N.sibirica,H.ammodendron,and P.euphratica.The water sources and utilization ratios of desert vegetation varied across different growth stages.Throughout the growing period,H.ammodendron mainly used groundwater,whereas the water source proportions used by N.sibirica varied greatly throughout the growing season.In spring,plants mainly relied on surface soil water,with a contribution rate of 80%-94%.However,in summer,the proportion of deep soil water used was 31%-36%;and in autumn,the proportion of middle soil water used was 33%-36%.H.caspica mainly relied on topsoil water in spring and autumn,and the proportion of soil water in the middle layer slightly increased to 20%-36%in summer.P.euphratica mainly used intermediate soil water in spring with a utilization rate of 53%-54%.In summer,groundwater was the main source,with a utilization rate of 72%-88%,and only 2%-5%came from river water,whereas in autumn,the river water utilization rate rose to 11%-21%.The results indicated that there were significant differences in water use sources during the growing period for desert vegetation in arid areas.This research provides a theoretical basis for understanding water use mechanisms,water adaptation strategies,and vegetation restoration and management in arid areas.展开更多
Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water scarcity.Evaluating a...Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water scarcity.Evaluating and integrating precipitation datasets from different sources to accurately characterize precipitation patterns has become a challenge to provide more accurate and alternative precipitation information for the region,which can even improve the performance of hydrological modelling.This study evaluated the applicability of widely used five satellite-based precipitation products(Climate Hazards Group InfraRed Precipitation with Station(CHIRPS),China Meteorological Forcing Dataset(CMFD),Climate Prediction Center morphing method(CMORPH),Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record(PERSIANN-CDR),and Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis(TMPA))and a reanalysis precipitation dataset(ECMWF Reanalysis v5-Land Dataset(ERA5-Land))in Xinjiang using ground-based observational precipitation data from a limited number of meteorological stations.Based on this assessment,we proposed a framework that integrated different precipitation datasets with varying spatial resolutions using a dynamic Bayesian model averaging(DBMA)approach,the expectation-maximization method,and the ordinary Kriging interpolation method.The daily precipitation data merged using the DBMA approach exhibited distinct spatiotemporal variability,with an outstanding performance,as indicated by low root mean square error(RMSE=1.40 mm/d)and high Person's correlation coefficient(CC=0.67).Compared with the traditional simple model averaging(SMA)and individual product data,although the DBMA-fused precipitation data were slightly lower than the best precipitation product(CMFD),the overall performance of DBMA was more robust.The error analysis between DBMA-fused precipitation dataset and the more advanced Integrated Multi-satellite Retrievals for Global Precipitation Measurement Final(IMERG-F)precipitation product,as well as hydrological simulations in the Ebinur Lake Basin,further demonstrated the superior performance of DBMA-fused precipitation dataset in the entire Xinjiang region.The proposed framework for solving the fusion problem of multi-source precipitation data with different spatial resolutions is feasible for application in inland arid areas,and aids in obtaining more accurate regional hydrological information and improving regional water resources management capabilities and meteorological research in these regions.展开更多
基金supported by the Scientific Research Foundation for High-Level Talents of Shihezi University(RCZK2018C41,CXRC201801,RCZK2018C22)the National Natural Science Foundation of China(41661040,U1803244)the Scientific and Technological Research Projects of Xinjiang Production and Construction Corps,China(2021AB021)。
文摘Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake Basin in Xinjiang,Northwest China.In this paper,variations of runoff,temperature,precipitation,reference evapotranspiration,lake area,socio-economic water usage,groundwater level and water quality in the Ebinur Lake Basin from 1961 to 2015 were systematically analyzed by the Mann-Kendall test methods(M-K)mutation test,the cumulative levelling method,the climate-sensitive method and land-use change index.In addition,we evaluated the effects of human activities on land use change and water quality.The results reveal that there was a significant increase in temperature and precipitation from 1961 to 2015,despite a decrease in reference evapotranspiration.The Wenquan station was not significantly affected by human activities as it is situated at a higher altitude.Runoff at this station increased significantly with climate warming.In contrast,runoff at the Jinghe station was severely affected by numerous human activities.Runoff decreased without obvious fluctuations.The contributions of climate change to runoff variation at the Jinghe and Wenquan stations were 46.87%and 58.94%,respectively;and the contributions of human activities were 53.13%and 41.06%,respectively.Land-use patterns in the basin have changed significantly between 1990 and 2015:urban and rural constructed lands,saline-alkali land,bare land,cultivated land,and forest land have expanded,while areas under grassland,lake,ice/snow and river/channel have declined.Human activities have dramatically intensified land degradation and desertification.From 1961 to 2015,both the inflow into the Ebinur Lake and the area of the lake have declined year by year;groundwater levels have dropped significantly,and the water quality has deteriorated during the study period.In the oasis irrigation area below the runoff pass,human activities mainly influenced the utilization mode and quantity of water resources.Changes in the hydrology and quantity of water resources were driven primarily by the continuous expansion of cultivated land and oasis,as well as the growth of population and the construction of hydraulic engineering projects.After 2015,the effects of some ecological protection projects were observed.However,there was no obvious sign of ecological improvement in the basin,and some environmental problems continue to persist.On this basis,this study recommends that the expansion of oasis should be limited according to the carrying capacity of the local water bodies.Moreover,in order to ensure the ecological security of the basin,it is necessary to determine the optimal oasis area for sustainable development and improve the efficiency of water resources exploitation and utilization.
基金the National Natural Science Foundation of China(41873028,41501541)。
文摘There is a lack of research on soil microplastics in arid oases considering the rapid economic development of northwestern China.Here,we studied the occurrence and sources of microplastics in soil,as well as the relationships between microplastics and adsorbed heavy metals in the Ebinur Lake Basin,a typical arid oasis in China.Results showed that(1)the average microplastic content in all soil samples was 36.15(±3.27)mg/kg.The contents of microplastics at different sampling sites ranged from 3.89(±1.64)to 89.25(±2.98)mg/kg.Overall,the proportions of various microplastic shapes decreased in the following order:film(54.25%)>fiber(18.56%)>particle(15.07%)>fragment(8.66%)>foam(3.46%);(2)among all microplastic particles,white particles accounted for the largest proportion(52.93%),followed by green(24.15%),black(12.17%),transparent(7.16%),and yellow particles(3.59%).The proportions of microplastic particle size ranges across all soil samples decreased in the following order:1000-2000μm(40.88%)>500-1000μm(26.75%)>2000-5000μm(12.30%)>100-500μm(12.92%)>0-100μm(7.15%).FTIR(Fourier transform infrared)analyses showed that polyethylene terephthalate(PET),polypropylene(PP),polycarbonate(PC),polyethylene(PE),and polystyrene(PS)occurred in the studied soil;(3)random forest predictions showed that industrial and agricultural production activities and the discharge of domestic plastic waste were related to soil microplastic pollution,in which agricultural plastic film was the most important factor in soil pollution in the study area;and(4)seven heavy metals extracted from microplastics in the soil samples showed significant positive correlations with soil pH,EC,total salt,N,P,and K contents(P<0.01),indicating that these soil factors could significantly affect the contents of heavy metals carried by soil microplastics.This research demonstrated that the contents of soil microplastics are lower than other areas of the world,and they mainly come from industrial and agricultural activities of the Ebinur Lake Basin.
基金Natural Science Foundation of Xinjiang Uygur Autonomous Region,No.2021D01A118National Natural Science Foundation of China,No.U1803244Open Project of Xinjiang Laboratory of Lake Environment and Resources in Arid Area,No.XJNUSYS2019B18。
文摘In arid and semi-arid environments,desert vegetation plays an important role in preventing soil erosion by wind and helps maintain the stability of desert and oasis ecosystems.Four types of typical desert vegetation,namely Populus euphratica,Haloxylon ammodendron,Nitraria sibirica,and Halostachs caspica,corresponding to different habitats(i.e.,river bank,sand dune,desert,and salt marsh)were chosen as the model vegetation in this research.Theδ^(2)H andδ^(18)O for rainwater,soil water,and plant water were applied to identify the water sources and quantify the proportions of different water sources used over the entire plant growth period(from March to October).The results showed that the precipitationδ^(2)H andδ^(18)O in the Ebinur Lake basin varied from-142.5‰to-0.6‰and from-20.16‰to 1.20‰,respectively.The largestδ^(2)H andδ^(18)O values occurred in summer and the smallest in winter.The soil waterδ^(2)H andδ^(18)O of the four habitats decreased gradually with increasing depth.Theδ^(2)H andδ^(18)O values of water extracted from the stems of the four plants had similar variation trends,that is,the maximum was observed in spring and the minimum in summer.Among the four plants,H.caspica had the highest stable isotopic values in the stem water,followed by N.sibirica,H.ammodendron,and P.euphratica.The water sources and utilization ratios of desert vegetation varied across different growth stages.Throughout the growing period,H.ammodendron mainly used groundwater,whereas the water source proportions used by N.sibirica varied greatly throughout the growing season.In spring,plants mainly relied on surface soil water,with a contribution rate of 80%-94%.However,in summer,the proportion of deep soil water used was 31%-36%;and in autumn,the proportion of middle soil water used was 33%-36%.H.caspica mainly relied on topsoil water in spring and autumn,and the proportion of soil water in the middle layer slightly increased to 20%-36%in summer.P.euphratica mainly used intermediate soil water in spring with a utilization rate of 53%-54%.In summer,groundwater was the main source,with a utilization rate of 72%-88%,and only 2%-5%came from river water,whereas in autumn,the river water utilization rate rose to 11%-21%.The results indicated that there were significant differences in water use sources during the growing period for desert vegetation in arid areas.This research provides a theoretical basis for understanding water use mechanisms,water adaptation strategies,and vegetation restoration and management in arid areas.
基金supported by The Technology Innovation Team(Tianshan Innovation Team),Innovative Team for Efficient Utilization of Water Resources in Arid Regions(2022TSYCTD0001)the National Natural Science Foundation of China(42171269)the Xinjiang Academician Workstation Cooperative Research Project(2020.B-001).
文摘Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water scarcity.Evaluating and integrating precipitation datasets from different sources to accurately characterize precipitation patterns has become a challenge to provide more accurate and alternative precipitation information for the region,which can even improve the performance of hydrological modelling.This study evaluated the applicability of widely used five satellite-based precipitation products(Climate Hazards Group InfraRed Precipitation with Station(CHIRPS),China Meteorological Forcing Dataset(CMFD),Climate Prediction Center morphing method(CMORPH),Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record(PERSIANN-CDR),and Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis(TMPA))and a reanalysis precipitation dataset(ECMWF Reanalysis v5-Land Dataset(ERA5-Land))in Xinjiang using ground-based observational precipitation data from a limited number of meteorological stations.Based on this assessment,we proposed a framework that integrated different precipitation datasets with varying spatial resolutions using a dynamic Bayesian model averaging(DBMA)approach,the expectation-maximization method,and the ordinary Kriging interpolation method.The daily precipitation data merged using the DBMA approach exhibited distinct spatiotemporal variability,with an outstanding performance,as indicated by low root mean square error(RMSE=1.40 mm/d)and high Person's correlation coefficient(CC=0.67).Compared with the traditional simple model averaging(SMA)and individual product data,although the DBMA-fused precipitation data were slightly lower than the best precipitation product(CMFD),the overall performance of DBMA was more robust.The error analysis between DBMA-fused precipitation dataset and the more advanced Integrated Multi-satellite Retrievals for Global Precipitation Measurement Final(IMERG-F)precipitation product,as well as hydrological simulations in the Ebinur Lake Basin,further demonstrated the superior performance of DBMA-fused precipitation dataset in the entire Xinjiang region.The proposed framework for solving the fusion problem of multi-source precipitation data with different spatial resolutions is feasible for application in inland arid areas,and aids in obtaining more accurate regional hydrological information and improving regional water resources management capabilities and meteorological research in these regions.
