An Analysis of the Change of Rainfall-Runoff Characteristics in the Lijiang River Basin under Different Types of Landuse

In order to reveal the impact of landuse on rainfall-runoff characteristics of the basin under changing environments,a lumped hydrological model MODHYDROLOG is selected to simulate the daily runoff in the Lijiang River Basin from 2008 to 2016. Under the scenarios of human activities and climate change in different periods,the correlation between landuse and time-varying parameters of the model is analyzed to reveal the changes of rainfall-runoff characteristics of the basin,and the dynamic quantitative perception of watershed characteristics affected by human activities is explored. The results show that the MODHYDROLOG model can simulate perfectly the daily runoff process of Lijiang River Basin,with NSE and R2both exceeding 0.7 and Dv within 0.2%. Most landuse changes are closely related to groundwater-related parameters,such as dlev,k1 and k3,and some are related to vegetation-related parameters in different degrees,while the infiltration and depression-related parameters does not show significance. The analysis of the impact of landuse on runoff generation shows that cultivated land and forest inhibited the rise of groundwater base level has increased deep groundwater leakage and promoted the exchange of base flow,which is conducted to the recharge of aquifer to river channel,while the mechanism of water areas and urban and rural areas is opposite. Grassland has reduced the proportion of interflow and increased the recharge of groundwater. The results of this research can provide a reference for the hydrological simulation and prediction of watershed under changing environments.