塔里木河流域水储量变化及绿洲生态安全评估OACSTPCD

Oases are unique and ecologically sensitive landscape types in arid and semiarid regions and play a crucial role in sustaining human survival and socioeconomic development.However,climatic changes and human activities are causing drastic changes to water resources and the oasis eco-environment.This study analyzes ter-restrial water storage changes and assesses the ecological security of oases in the Tarim River Basin of Xinjiang,China.The assessment was performed using the fraction of vegetation cover,a remote sensing ecological index,and net primary productivity(NPP)using the Carnegie-Ames-Stanford approach.The analysis used moderate-res-olution imaging spectroradiometer satellite images,GRACE data,land use data,and climatic gridded and ob-served data from 2002 to 2020.The results indicate the following:(1)Terrestrial water storage in the Tarim River Basin decreased at a rate of 0.27 mm per month.Spatially,terrestrial water storage in the northern and western re-gions of the Tarim River Basin exhibited a negative trend,whereas that in the southern regions of the Basin showed a positive trend.(2)The total oasis area in the Tarim River Basin expanded by 6.49%(0.42×104 km2)from 2000 to 2020.The ecological security of the basin improved,and the eco-environment ranged from poor to general grade.Approximately 69%of the region's eco-environment improved,whereas the area of ecological degradation was less than 5%.The normalized difference vegetation index increased from 0.13 in 2000 to 0.16 in 2020,the fraction of vegetation cover increased by 36.79%,and the NPP expanded by 31.55%in the past 20 years.(3)Rising temperatures and precipitation contributed to increased downstream river runoff and spatiotem-poral variability of water resources in the Tarim River Basin.However,human activities are a key factor in the ex-pansion of oases.