Impact of climate and land use change on runoff in Huanglei River Basin

A soil and water assessment tool (SWAT) was developed to simulate monthly hydrograph from 2011-2018 in Huangleihe Basin in Jiaodong Peninsula, and to analyze impact on runoff by changes in land use and climate．R² and E_NS were found to be 0.74 and 0.71, 0.69 and 0.72 respectively for calibration and validation periods, suggesting that the model was capable for runoff simulation in the watershed. Increases in runoff under integrated scenario were found to take place in response to changes in climate, land use and in both; climate was found stronger than land use in doing so. Analysis of climate change indicated that changes in runoff were positively correlated with changes in precipitation, negatively correlated with changes in temperature. Four extreme sub-scenarios of land use were found to increase annual runoff by 5.04% and 2.71%, or to decrease by 8.17% and 4.23%, suggesting that forest land intercepts rainfall ion, residential and cultivated lands do not. Strengthening prediction of rainfall and optimizing land use structure would mitigate negative hydrological effects due to climate change, thereby achieving water balance.