滇池流域不透水表面的水环境影响分析及其治理措施

Water environmental impacts of impervious surfaces and control measures in Dianchi Lake Basin,China

当前滇池水污染的治理措施主要关注农业面源污染和城市生活污水,忽视了城市化过程中不透水表面带来的城市面源污染问题。采用基于遥感、GIS的生态环境影响评估模型,分析了滇池流域不透水表面的水环境效应。结果表明：不透水表面面积增加可导致流域地表径流量增加以及水质下降,进而导致流域水环境问题日益严重;当子流域不透水表面覆盖率（ISC）控制在0%~8%时,流域水环境状况良好;当ISC增长到8%~23%时,流域水环境受到影响;超过23%时,将形成不可逆转的水体污染,流域水环境严重退化。根据滇池17个子流域的不透水表面覆盖率大小,提出了滇池流域的子流域分类规划与治理思路,详细列出了分类治理的具体措施。

The existing control measures in Dianchi Lake focus mainly on agricultural nonpoint source pollution and city sewage but ignore the urban nonpoint source pollution resulting from increased impervious surfaces in the process of urbanization. This work analyzed the aquatic environmental impacts of impervious surfaces by using an eco-environmental impact assessment model based on remote sensing and GIS. The results show that increased impervious surfaces led to increased runoff and declining water quality. The water quality of Dianchi Lake Basin was good when the subbasin impervious surfaces cover（ ISC） was 0% to 8%,was affected when the subbasin ISC ranged from 8% to 23%,and was poor and irreversible when subbasin ISC was greater than 23%. According to the ISC of 17 subbasins in the Dianchi Lake Basin,this work proposes classification,planning,and governance ideas based on subbasin level,and detailed lists specific to measures of classification governance.