摘要:
抚仙湖是我国水质较好的大型淡水湖泊之一,其总体水质为I类.近年来由于流域内开发强度增加,水体水质呈现下降的趋势.为探究流域土地利用变化可能对湖泊水质产生的影响,利用1992-2010年的Landsat TM和ETM+数据,结合GIS技术和统计学方法,分析了流域内土地利用及景观格局变化与湖泊水质的响应关系.研究结果显示:抚仙湖水体面积缩小,流域内林地和耕地面积总体呈减小趋势,与水质污染指数变化呈显著负相关;交通运输用地和建设用地增长迅速,与水质污染指数响应呈显著正相关;景观斑块数目、形状指数等景观格局指数增加,流域景观格局破碎化加重,与水质污染指数变化呈显著正相关;土地利用及景观格局指数可以作为研究抚仙湖水质变化的重要指标.
Abstract:
The water quality of the Fuxian Lake basin has been deteriorating during the past 20 years.To evaluate the impacts of land use changes on water quality,the authors used Landsat TM and ETM + from 1992 to 2010,in combination with GIS methods and correlation analysis,to explore the relationships of water quality with land use structure and landscape patterns respectively in the period of 1992-2010.The results showed that the surface water area,forest coverage and cultivated land area all displayed a decreasing trend,with a negative correlation of water quality with water area,forest coverage and cultivated land area respectively.There was a rapid expansion of transportation and construction land,which exhibited a significant positive correlation with water quality.Both the landscape diversity index and Shannon' s diversity index (SDI) exhibit a significant positive correlation with water quality,and landscapes become more fragmented with an increase in patch number and shape complexity.
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