The impact of land use and land cover changes on runoff in a semi-arid river basin

Land use is a key factor controlling the hydrological behaviour of catchments. To have an efficient water management in the basin, it is useful to examine how land use and land cover changes (LUCC) would affect various hydrological processes. This paper aims to assess the effects of such changes on the runoff in the Laohahe basin, the head-water tributary of West Liaohe. The land use and land cover changes were significant in the Laohahe basin over the period 1980-2000. Precipitation and runoff data from 1977 to 2008 in the basin were analysed by using time series contrasting method for assessing characteristics and variation tendency of annual runoff. The results suggest an insignificant decline in runoff. Through the VIC-3L model for the periods prior to and after abrupt runoff changes, human activity, rather than climatic change, is identified as the main driving factor for runoff decline in Laohahe basin.