Basin water environmental effects of urban landscape

The research of Basin urban landscape changing effects the water environment system is a hot topic of water environmental effects. To achieve the goal of unity between urban development and water environment protection, we need science to judge the impact of urban landscape on the water environment, especially on the impervious surface (IS). In this paper, the impervious surface coverage (Impervious Surfaces Coverage, ISC) was taken as an indicator to evaluate measurable basin water environments with the ISC of each sub-basin to study the influence of IS on water environments. The results showed that the pollution was caused as much as the agricultural nonpoint source when the basin´s ISC more than 10%. If it is not controlled (eg ISC>25%), there will cause the irreversible pollution of water bodies. In the 30 sub-basins of the Erhai basin, there have five sub-basins, whose ISC >10%,two sub-basins´ ISC >20%, one sub-basin´s ISC >25% in the year 2000.But there are three sub-basins´ ISC > 10%, 3 sub-basins´ ISC > 20%, 2sub-basins´ ISC > 25% in 2010. Overall, the ISC showed an increasing trend in the sub-basins.