Human Activity Intensity Assessment by Remote Sensing in the Water Source Area of the Middle Route of the South-to-North Water Diversion Project in China

Human activities have significantly affected the natural eco-environment, which could lead to land cover changes. The human activity intensity of land surface (HAILS) represent human activity at the regional scale and can be monitored efficiently over a long term based on land cover data collected by remote sensing techniques. In this study, we quantify the HAILS index for 2000, 2010, and 2015 based on land cover, and analyze its temporal and spatial variation to illustrate the potential influence of human activities on the water quality in the water source area of the Middle Route of the South-to-North Water Diversion Project (MR-SNWDP). The results show that from 2000 to 2015, the HAILS decreased in general but increased with the highest increment of 78.4% around water resources. The area showing high values of HAILS increased at a rate of 30.8% from 2000 to 2015. In the riparian zone around the water body, the HAILS rose at an increment of 0.68% in 2010 to 0.05% in 2015. On the basis of the variation of the HAILS, it has been revealed that human activities, increased mainly around water bodies, may increase the risk of water pollution.