Precipitation change and human impacts on hydrologic variables in Zhengshui River Basin, China

Climate change and anthropogenic impacts on hydrologic variables have received significant attention in recent years. We assessed stream flow and water level in the Zhengshui River basin, China, in the period 1960 to 2003 in response to precipitation variation and anthropogenic factors. Analyses of daily discharge and water level records, and derived annual, seasonal and monthly series, showed that Zhengshui River flows had a significant increasing trend, with an abrupt change point in 1990. There was a significant decreasing water level trend with an abrupt change point in 1995. Human activities and precipitation contributed 53 and 47%, respectively, to increase in stream flow during 1991-2003. Anthropogenic activities such as sand dredging, dominated the decrease in water level during 1994-2003. Human-induced land use change, soil erosion and sand excavation driven by rapid economic development have played a more important role than precipitation variation in hydrological changes in the Zhengshui River basin over the past 50 years.