半干旱地区遥感生态指数的构建及应用

基于2001—2018年永登县5幅遥感影像，利用绿度、湿度、盐度、沙度指数耦合构建半干旱地区遥感生态指数（SA-RSEI）,并应用SA-RSEI指数对永登县生态环境质量进行定量评价。结果表明：在2001—2018年间永登县生态环境质量由较差提升至一般，生态环境等级优良以上的区域面积占比逐渐上升，较差和差等级面积占比逐渐下降；通过空间相关性分析可知，GDVI和WET为正向指标，DI和SI为负向指标；通过LISA聚类图发现空间分布是聚集的，而不是随机的；高-高聚集区主要集中于连城国家级自然保护区和奖俊埠林场，低-低聚集区主要集中在中部黄土丘陵区。

Construction and Application of Remote Sensing Ecological Index in Semi arid Region

Based on 5 remote sensing images of Yongdeng County from 2001 to 2018, the remote sensing ecological index of semi-arid region (SA-RSEI) was constructed by coupling greenness, humidity, salinity and sand index, and was applied to quantitatively evaluate the ecological environment quality of Yongdeng County. The results showed that from 2001 to 2018, the ecological environment quality in the study area improved from relatively poor to average. The proportion of area with good ecological environment grade and above increased gradually, and the proportion of area with relatively poor and poor grade decreased gradually. According to spatial correlation analysis, GDVI and WET were positive indicators, DI and SI were negative indicators. It was found that the spatial distribution was aggregated rather than random through LISA cluster diagram. High-high concentration areas were mainly concentrated in Liancheng National Nature Reserve and Jiangjunbu Forest Area, and low-low concentration areas were mainly concentrated in the Loess Hilly Area in the middle.