基于RS和GIS技术的乌江流域生态环境质量现状诊断

Diagnosis of eco-environment quality in Wujiang River watershed based on RS and GIS

乌江位于云贵高原斜面上,是长江上游南岸最大的支流,地质地貌独特,岩溶地貌广泛发育,由于长期不合理大规模开发利用活动,水土流失严重,石漠化问题突出,生态质量受到重大威胁。本文以乌江流域(位于贵州省境内)41个地区为研究区,以2010年TM遥感影像为主要数据源,运用RS和GIS技术获取景观格局信息,构建乌江流域生态环境质量评价指标体系,采用熵权法与GIS图形叠置法相结合,对研究区生态环境质量状况进行评价,在此基础上,运用系统聚类法划分生态环境质量类型,将乌江流域生态环境质量划分为良好(Ⅰ)、较好(Ⅱ)、一般(Ⅲ)、较差(Ⅳ)4个级别。结果显示:乌江流域生态环境质量属于良好、较好、一般、较差的面积分别为7 710.8km2、26 208.3km2、15 704.3km2、16 106.1km2,所占比重分别为11.7%、39.9%、23.9%、24.5%。总体上,流域的西北、西南地区生态环境质量较差,而流域的东北地区生态环境质量较好,不同县区生态环境质量差异显著。

The Wujiang river watershed lies on the Yunnan-Guizhou plateau slope,is the largest branch of the south bank of the upper Yangtze River,has unique geology and geomorphology and widely developed karst landform.Owing to long-term irrational exploitation and utilization on a large scale,the river watershed is confronted with serious soil and water loss and outstanding desertification problems.By using the TM ima-ges of the Wujiang river watershed in 2010 as the main information source,the paper,takes 41 regions （cit-ies,counties and districts）in the Wujiang river watershed （in Guizhou province）as study area,extracts land use information and landscape pattern indexes based on RS and GIS,constructs the evaluation index system of the ecological quality in the Wujiang river watershed,determines the index weight by entropy method, combines with GIS graphic overlay method,evaluates the ecological environment quality situation of the 41 regions.Based on the above works,the ecological quality in the Wujiang river watershed divided into four levels：good（Ⅰ）,relatively good（Ⅱ）,general（Ⅲ）and poor （Ⅳ）.The research result shows that the area of good,relatively good,general and poor ecological environment quality in the Wujiang river watershed in 2010 year is 7 710.8 km^2 ,26 208.3 km^2 ,15 704.3 km^2 and 1 6 106.1 km^2 respectively,and the weight is 1 1.7 %,39.9 %,23.9 % and 24.5 % respectively.On the whole,the ecological environment is of inferior quality in northwest and southwest Wujiang river watershed,but the ecological environment quality is better in the northeast.And the ecological environment quality in different regions has obvious differences.