Impacts of Impervious Cover on River Water Quality: Case Study of Shiqi River Watershed

This chapter examines the spatial scale effects of human activities, taking Shiqi River watershed in Zhongshan City as a case study. Impervious Cover was adopted to indicate intensity and spatial distribution of human activities. Its definition, estimation, impacts on river ecosystem health and scale issues in previous studies are reviewed. Considering Shiqi River watershed is a typical urbanizing watershed, AGREE algorithm through Digital Elevation Model (DEM) reconditioning of ArcHydro Module in ArcGIS 10.2 is introduced to accurately divide the sub-watersheds. The relationship between IC percentages and river water quality are examined at four naturally spatial scales as well as their buffer zones, and further discussions are conducted on the artificial sewage collection area scale.