基于改进型遥感生态距离指数的秀山县生态环境质量评估

快速准确评估区域生态环境质量与变化对于喀斯特石漠化地区的生态监测具有重要意义。通过选取重庆市秀山县为研究区,以1990年、2002年和2016年Landsat5/8影像为主要数据源,提取石漠化指数(RI)、建筑裸土指数(NDSI)、湿度指数(WI)、植被指数(NDVI)建立改进型遥感生态距离指数(MRSEDI),对秀山县生态环境质量及变化进行评估。结果发现:①秀山县1990年、2002年和2016年MRSEDI均值分别为0.617、0.665和0.748,呈现上升趋势;②秀山县1990—2016年间生态环境质量优良等级区域面积呈现上升趋势,优良等级区域面积从1990年的55.94%增加到2016年的82.67%;③26 a间,秀山县大部区域生态环境质量变化情况为变好和不变,其中变好区域占全县面积的54.01%,不变区域占全县面积的34.49%。秀山县生态环境质量较好,且生态环境呈现继续变好趋势,秀山县26 a间一系列生态环境保护措施具有一定成效。

Assessment of Eco-environmental Quality in Xiushan County Using Modified Remote Sensing Ecological Distance Index Model

A rapid and accurate assessment of regional eco-environmental quality and its change is of important reference to ecological monitoring in the karst rocky desertification region. With Xiushan County in Chongqing as research area and the Landsat 5/8 imagines as main data resources, the eco-environmental quality and its change in the Xiushan County were assessed by establishing modified remote sensing ecological distance index (MRSEDI), which was calculated by rocky desertification index (RI), normalized difference built-up and soil index (NDSI), wetness index (WI), and normalized difference vegetation index (NDVI). Results unveiled that: 1) The average values of MRSEDI in 1990, 2002 and 2016 were 0.617, 0.665 and 0.748, respectively, presenting a rising trend. 2) The area of excellent and good eco-environmental quality in the research area increased over the 26 years, from 55.94% in 1990 to 82.67% in 2016. 3) The eco-environmental quality in most of the study area changed for the better or remained unchanged over the 26 years. The improved area accounted for 54.01%, while the unchanged area occupied 34.49%. In conclusion, Xiushan county boasts a good and ever-improving eco-environmental quality, implying that the eco-environmental protection measures over the 26 years are effective.