Evaluating Urbanization and Its Impacts on Local Hydrological Environment Change in Shijiazhuang, China, Using Remote Sensing

This study illustrates urbanization in Shijiazhuang city and its impacts on change in local micro-climate and hydrological environments using remote sensing. First, a pair of Landsat TM images of the study area acquired in 1987 and 2001, were used to detect urban expansion and associated land cover change. Together with detecting urban expansion and associated land cover/use change, we used the remote sensing data in the thermal-infrared band to analyse the thermal environmental change due to urbanization. In order to evaluate the impacts on hydrological cycle, we calculated and compared the water balance in 1985–1989 and 1999–2003. Results suggest the change in water balance due to urbanization is significant. Evapotranspiration is reduced by about 20%, equivalent to 100 mm per year, and the annual surface runoff generation increases 32%. However, a significant enlargement of the urban heat island is also observed.