Impact of human activities on stream flow in the Biliu River basin, China

摘要

The obvious decline in stream flow to the Biliu River reservoir over the period 1990–2005 has raised increasing concerns.nClimate change and human activities, which mainly include land use changes, hydraulic constructions and artificial waternconsumption, are considered to be the most likely reasons for the decline in stream flow. This study centres on a detailed analysisnof the runoff response to changes in human activities. Using a distributed hydrological model, (Soil and Water Assessment Tool),nwe simulated runoffs under different human activity and climate scenarios to understand how each scenario impacts stream flow.nThe results show that artificial water consumption correlates with the precipitation (wet, normal and dry) of the year in questionnand is responsible for most of the decrease in runoff during each period and for each different wetness year. A Fuzzy InferencenModel is also used to find the relationship between the precipitation and artificial water consumption for different years, as wellnas to make inferences regarding the future average impact on runoff. Land use changes in the past have increased the runoff bynonly a small amount, while another middle reservoir (Yunshi) has been responsible for a decrease in runoff since operation begannin 2001. We generalized the characteristics of the human activities to predict future runoff using climate change scenarios. Thenfuture annual flow will increase by approximately 10% from 2011 to 2030 under normal human activities and future climatenchange scenarios, as indicated by climate scenarios with a particularly wet year in the next 20 years. This study could serve as anframework to analyse and predict the potential impacts of changes both in the climate and human activities on runoff, which cannbe used to inform the decision making on the river basin planning and management. Copyright © 2012 John Wiley & Sons, Ltd.