黄土高原沟壑区生态环境状况遥感动态监测——以陕西省富县为例

基于主成分分析耦合植被指数、湿度指数、地表温度和裸土指数4个遥感评价指标,对黄土高原丘陵沟壑区陕西省富县1995—2014年的生态环境质量进行评价.结果表明: 基于主成分分析确定权重的遥感生态指数能客观定量揭示区域生态环境的变化;富县生态环境现状整体上属于良好级别,植被覆盖度较高,生物多样性较丰富;1995—2014年,富县生态环境总体上得到了较大改善,生态环境质量综合指数由3.17上升到3.53,牛武镇的生态环境质量整体状况最好,全县由西北方向到东南方向,生态环境质量改善的幅度逐渐递增,其中,交道镇和南道德乡变化最大;研究期间,生态环境质量等级下降地区的面积占全县总面积的16.7%,生态质量等级提高的面积占富县总面积的42.7%,生态环境等级提高的地区主要分布在县域中部的高塬和丘陵沟壑地、县东北部的土石低山区、西南的子午岭自然保护区.

Dynamic monitoring of ecological environment in loess hilly and gully region of Loess Plateau based on remote sensing: A case study on Fuxian County in Shaanxi Province,Northwest China.

Based on the principal component analysis (PCA), four ecological evaluation indicators including vegetation index, wet index, land surface temperature and soil index were combined to evaluate the ecological environment quality of Fuxian County in hilly and gully area of Loess Plateau from year 1995 to 2014. The results showed that the RSEI integrated RS and PCA method could reveal regional ecological changes objectively and quantitatively. The level of overall regional ecological status in Fuxian County was good with a high vegetation fraction and rich biodiversity. The synthetical ecological environment quality index increased from 3.17 to 3.53 indicating the ecological environment had been improved greatly in recent 20 years. The area with best ecological environment quality was located in Niuwu town. The magnitude of change increased progressively from northwest to southeast, and the biggest change occurred in Jiaodao and Nandaode towns. From 1995 to 2014, the areas with decreased and increased ecological environment quality were 16.7% and 42.7% of the study area, respectively, and the improved regions were mainly distributed in plateau and hilly area in the center, rocky low mountainous area in northeast and the Ziwuling Nature Reserve area in southwest of the county.