基于GEE的嘉陵江流域生态环境质量演变及驱动因子分析OA

Jialing River Basin is a tributary with the largest catchment area and a dense population in the Yan-gtze River system.Unveiling the dynamic evolution and the driving factors of the ecological environment quality in this basin is of great significance for the protection of the Yangtze River.In this study,the long-term series and multi-spatiotemporal scale remote sensing data of the Jialing River Basin were obtained by the Google Earth Engine(GEE).The Remote Sensing Ecological Index(RSEI)was established with four ecolog-ical elements—greenness,dryness,humidity,and heat—to clarify the spatiotemporal evolution pattern of the ecological environment quality of the basin.The geographic detector was used to clarify the driving factors of the ecological environment evolution in the basin.The results are summarized as follows:(1)There were large spatiotemporal variations in the ecological environment quality of the basin from 2001 to 2022.The average RSEI value was 0.22-0.69,and the ecological environment quality was improved.The slightly improved are-a accounted for 74.42%of the basin area,mainly located in the northern part of the basin,while the signifi-cantly improved area was distributed in the eastern part of the basin.The area of severe degradation and slight degradation was very small,mainly in the Fujiang River Basin,the southwest of the Donghe/Xihe River Basin,the southwest of the Baihe River Basin,and the partial area of the Qujiang River Basin.(2)The spatial patterns of the RSEI and the Ecological Index(EI)in the study area were generally consistent,while the RSEI was more sensitive in quantifying the very good and poor grades and the EI was suitable for evaluating the good and medium grades.(3)Annual precipitation,annual mean temperature,and altitude were the key driving factors affecting the ecological environment quality of the basin,followed by population density and land use type.All factors had strong synergistic enhancement effect upon interaction.The results of this study provide a reference for the monitoring and evaluation of the ecological environment in the basin and the determination of the optimal ecological environment.