干旱区生态环境质量的地形梯度效应——以轮台县为例

Topographic Gradient Effect of Ecological Environment Quality in Arid Areas:A Case Study of Luntai County

为了揭示地形梯度对干旱区生态环境质量的影响,利用2014、2018和2023年3期Landsatt8OLI遥感影像和数字高程模型(DEM)数据,采用遥感生态指数(RSEI)、主成分分析等方法,分析了轮台县生态环境质量的时空演变规律,并探讨了遥感生态指数在地形梯度上的变化特征。研究结果表明:干度和热度是影响轮台县生态环境质量的主要因素,而湿度和绿度对生态环境质量的影响较小;高海拔地区的生态环境质量较好,在4级地形梯度上生态环境质量最好,而低海拔地区的生态环境质量较差;在2014─2023年期间,轮台县的整体生态环境质量水平呈现先降后升的趋势,以差和较差等级为主;遥感生态指数等级的变化图谱以稳定型和后期变化型为主。

In order to reveal the influence of topographical gradients on the ecological environment quality in arid regions,the spatial and temporal evolution patterns of ecological environment quality in Luntai County was analyzed by Landsat8OLI remote sensing images and digital elevation model(DEM)data from 2014,2018,and 2023,remote sensing ecological index(RSEI)and principal component analysis,and the change characteristics of remote sensing ecological index on topographic gradient were explored.The results show that aridity and temperature are the primary factors affecting the ecological environment in Luntai County,while humidity and greenness have little influence on ecological environment quality.Higher-altitude areas exhibit better ecological environment quality,and the fourth-level topographical gradient has the highest quality.Conversely,lower-altitude regions experience poorer ecological conditions.During 2014~2023,the overall ecological environment quality in Luntai County showed a trend of first decreasing and then increasing,predominantly categorized as“poor”and“very poor”within the county.The spectrum of changes in the remote sensing ecological index predominantly feature stable and later-changing types.