The change detection of impervious surface and its impact on runoff in the Qinhuai River Basin, China

The changes of impervious surface from 1986 to 2006 and the relationship between those changes and hydrological response were studied in the Qinhuai River Basin (2631 km²), which is located in the southwest of Jiangsu Province, P. R. China. A series of Landsat imagery during that period was employed to extract impervious area using the Linear Spectral Mixture Analysis. The results showed that impervious area increased from 2.9% in 1986 to 12.1% in 2006. The annual runoff and precipitation of the basin were collected to analyze the relationship between impervious surface area and annual runoff. Based on the regression analysis, it was found that the average annual runoff depth has increased by 26% since 2003 due to the increase of impervious area.