Assessment of Land Use Change Impacts on Hydrological Regimes in Haihe River Basin, China

In the recent years, the impacts of human activities on hydrological regimes become more obvious. These changes may not only influenced by satisfying the requirement of social development, but also by the government policy. In China, at the Haihe River Basin which is one of the most significant river basins contains several big cities such as Beijing the capital of China and Tianjin the fourth biggest city in China, the human activities directly have impacts on the land use distribution and indirectly on the regional rainfall–runoff process. Quantitatively and qualitatively identifying these impacts is significantly necessary for the local managers to update their current management plan. In this study, the semiarid Fuping catchment where located at the upstream of the Haihe River Basin was selected as the case study area to analyze the impacts of land use changes on hydrological regimes especially the rainfall–runoff process. By analyzing the daily rainfall and runoff data collected from eight stations, three statistic periods with different rainfall–runoff relationships were detected in Fuping area. Linking with the land use maps collected in 1970, 1980, 1995, 2000, 2004, 2006, and 2008, the changing points defined at 1979 and 1999 directly indicate the change of policy having impacts on the natural in China. Moreover, one distributed hydrological model ArcSWAT was applied in Fuping catchment to quantify the impacts of land use change (exchange between forest and pasture) on hydrological regimes such as surface water and groundwater. The model results show an obvious decrease of the surface flow when the Chinese government claimed the new policy “Conversion of degraded farm land into forest and grass land” at round 2000.