Effect of Lulc Change on Surface Runoff in Urbanization Area

In recent decades, urbanization has become a significant urban environmental and ecological concern, especially in most developing countries. In China, rapid urban sprawl has had a profound influence on runoff and results in larger and more frequent incidents of flooding in many urban areas. Therefore, evaluating the impacts of urbanization on runoff is of great important for urban planning policy makers and water/land resource management. The objective of this paper is to present a case study to derive land use/land cover (LULC) maps and further to investigate the long-term effects of LULC change on surface runoff in the fast urbanizing Beijing city. The LULC maps were derived from Landsat TM/ETM+ imagery (acquired in 1986, 1992, 1999, 2006, and 2009 respectively) using support vector machine (SVM) method. A Long-Term Hydrologic Impact Assessment (L-THIA) model was applied to assess the impacts of LULC change on surface runoff. Results indicated that the selected study area experienced rapid urbanization from 1986 to 2009. Urban areas increased from 4.18% in 1986 to 12.78% in 2009 in the whole area. Our results also indicated that the long-term surface runoff increased 25% in the whole area from 1986 to 2009, and the runoff increase was highly correlated with urban expansion (R = 0.91). This research can provide a simple method for policy makers to assess potential hydrological impacts of future planning and development activities.