Impacts of land use/land cover and climate change on hydrological cycle in the Xiaoxingkai Lake Basin

Abstract

Study regionThe Xiaoxingkai Lake Basin in China. Study focusWatershed hydrological simulation is a prominent aspect of hydrology, however, comprehensive analysis of lake basins based on hydrological simulation is rarely conducted. Therefore, we used the Soil and Water Assessment Tool (SWAT+) with dynamic land use/land cover (LULC) input and time-varying parameters to simulate streamflow of the Xiaoxingkai Lake Basin and estimate the impacts of LULC and climate change on streamflow during 1961–2017. We also evaluated the contributions of LULC and climate change to water volume in Lake Xiaoxingkai through a lake water balance analysis. New hydrologic insights for the regionThe simulated streamflow agrees well with observations at most stations (Nash-Sutcliffe Efficiency, NSE > 0.5, and goodness of fit, R2 > 0.8). Climate change has a positive effect on streamflow which dominates the streamflow variations during 1981–1995 and 2006–2017, whereas LULC change has a negative effect with a dominant role during 1996–2005. The volume of Lake Xiaoxingkai increased slightly at a rate of 0.12 × 106 m3 yr−1, with climate change contributing the most (77.25 %) to the increase, followed by direct human activities (47.50 %) and LULC change (−24.76 %). This study facilitates a better understanding of the hydrological cycle in the Xiaoxingkai Lake Basin under changing environments and is helpful for regional water resource management.