Spatial characteristics of the effects of climate change and human activities on runoff changes in the Luan River basin based on Budyko framework

Separating the effects of climate change and human activities on water resources is significant to the identification of leading influencing factors and the sustainable water resources management under a changing environment. Budyko hypothesis based method is an effective approach to separate the influences of climate change and human activities on regional water resources. In this study, six Budyko hypothesis-based methods are used to separate the effects in the Luan River basin using data 1958-2009. Firstly, the changing trends of precipitation, potential evapotranspiration and runoff are analyzed in the basin. The results show significant runoff and potential evapotranspiration declines while precipitation shows no significant changing trends in most of the region in the basin. Secondly, the six methods are used to investigate the influences of the two factors. Result show that the effects of human activities on runoff changes are stronger than that of climate change and the individual effects are various from different areas in the basin. Then the uncertainties brought by different potential evapotranspiration methods are discussed in this paper. The results obtained could provide scientific basis for the water resources management in the basin.