Quantitative assessment of the attribution of runoff change caused by four factors in the Haihe River basin

In this work, Water shortage problem is severe in the Haihe River basin (HRB). Furthermore, there is a statistically significant decreasing trend in runoff in the HRB. Quantitative assessment of the attribution of runoff change has important scientific significance to investigate the mechanism of water cycle and to support the sustainable utilization of water resources. Using regionalization approach, the model parameters of the VIC model are estimated for the whole HRB, and the natural runoff has been reconstructed. A quantitative attribution assessment framework for runoff change driven by temperature change, precipitation change, underlying surface change and water withdrawal has been constructed. The results indicates that human activities are the main reason for the runoff decrease in the HRB during 1956-2010. Generally, climate change and human activities account for 1/3 and 2/3 of the runoff decrease, respectively. In climate change, the contribution of precipitation decline (30%) is much higher than the impact of temperature increase (4%). In human activities, the influence of water withdrawal (55%) is greater than that of underlying surface change (11%). Spatially, from north HRB to south HRB, the impact of temperature change decreases, while the influence of precipitation change increases. Relatively, the breakpoint of runoff is later in the Luanhe River Basin, the contribution of water withdrawal in the north HRB and south HRB is higher than that in other regions, and the decreasing trend in runoff is slight and the attribution is uncertain in the Tuhaimajia River basin.