基于改进遥感生态指数模型的锡林郭勒草原生态环境评价

气候变化和人类活动的不断加剧,引发了生态环境质量问题,快速准确的评价区域生态环境的历史和现状,对实现人与自然的可持续协调发展具有重要意义。本文基于遥感技术分别反演出绿度因子、湿度因子、干度因子和热度因子,使用主成分分析法构建了改进遥感生态指数(MRSEI)。利用相关性分析,分析MRSEI的代表性,建立基于MRSEI的锡林郭勒草原生态环境评价模型,对锡林郭勒草原近26 a的生态环境进行了总体评价。结果表明:MRSEI可集中4种生态因子信息,能够准确的对生态环境进行评价;锡林郭勒草原从1991—2017年生态环境质量呈现出先好转后恶化的趋势; 1991年研究区上游的生态环境质量优于下游,生态环境质量东部优于西部; 2004年,研究区整体生态环境质量空间差异较1991年变化较大,上游大多数地区生态环境质量提升,但下游明显降低;至2017年,整个研究区生态环境质量全面降低,仅在锡林河上游两岸与流域的南部和东南部保持良和优良。

Evaluation of Ecological Environment in the Xilin Gol Steppe based on Modified Remote Sensing Ecological Index Model

Climate change and human activities continue to intensify and cause some ecological and environment quality problems. It is important to the sustainable and coordinated development of human and nature to quickly and accurately evaluate the historical and current situation of regional ecological environment. In this paper, four indicators including greenness, wetness, dryness and heat were retrieved using the RS means. Principal component analysis (PCA) was used to construct the modified remote sensing ecological index (MRSEI), and the representativeness of MRSEI was analyzed by correlation analysis. Based on MRSEI, the ecological environment evaluation model was developed for the Xilin Gol Steppe, and the overall evaluation of the ecological environment in the Xilin Gol Steppe in recent 26 years was conducted. The results showed that MRSEI could be used to collect the information of various ecological factors and evaluate the ecological environment accurately. From 1991 to 2017, the ecological environment quality in the Xilin Gol Steppe was improved at first and then degenerated. In 1991, the environmental quality in the upstream was better than that in the downstream, and it was better in the eastern part than that in the western part. In 2004, the spatial difference of the overall ecological environmental quality in the study area was obviously changed compared with that in 1991. The ecological environment quality in the upstream was improved but obviously decreased in the downstream. By 2017, the ecological environment quality in the whole study area was roundly reduced, and a good ecological environment was remained only along the upper banks of the Xilin River and the southern and the southeast parts of the drainage basin.