基于格网的太湖生态环境质量空间评价

将GIS格网空间分析技术应用于太湖生态环境综合评价，实现了全湖范围内多因素的综合评价，揭示太湖生态环境状况的空间分布规律。首先将太湖分为800个格网单元，在2002~2003年实测样点的水体、底泥、水生生物特征数据基础上，通过空间插值获得全部单元模拟值，然后进行格网叠加计算，通过层次分析法得出各单元综合评价值，将太湖分为好、较好、中等、较差、差5个等级区，生成太湖生态环境空间综合评价图。结果显示，评价结果与太湖实际情况基本相符，太湖生态环境质量基本上由东南向西北逐渐降低，中等以下地区占全部湖区的一半以上，整体状况偏差。

GRID-BASED SPATIAL EVALUATION OF ECO-ENVIRONMENTAL CONDITION OF TAIHU LAKE

With the grid spatial analysis technique of GIS,the multi-factor synthetic evaluation of eco-environmental condition was carried out for the whole Taihu Lake, and the spatial distribution internality of eco-environmental condition was posted. Firstly,the whole lake was divided into 800 grid cells,and based on the data of 11 factors-including water, organism and sediment-monitored at limited points from 2002 to 2003, the simulative value of all cells was obtained by spatial interpolation by the use of GIS. Secondly, the factor values were combined into a synthetic value for each cell by grid overlay calculation by GIS. By the synthetic value, the cells were divided into five levels including best, better, fair, worse and worst,and the evaluation map of the eco-environmental condition of Taihu Lake was obtained. The results showed that the eco-environmental quality decreased from southeast to northwest gradually,the area of worse level and worst level accounted for a majority of the lake,and the eco-environmental status is poor in general. It was also indicated that the study evaluated the eco-environmental quality of Taihu Lake objectively for the results accorded basically with the actual status of the lake.