Spatial heterogeneity of watershed runoff sensitivity to climate and underlying surface changes in humid and sub-humid climates in China

Abstract

Study region: Watershed of humid and sub-humid climate zones in China. Study focus: With the development of economy and society, changes in the global climate and underlying surface have led to great changes in regional water cycle. It is difficult to estimate the sensitivity of runoff change and spatial distribution of regional effect merely based on one basin. In this study, we systematically collected data from 83 basins in China and comprehensively analyzed and predicted the sensitivity of runoff change to climate and underlying surface parameters. New hydrological insight for the region: The unique aspect of this paper is using the Budyko coupled water-energy balance theory to systematically assess the sensitivity of runoff change and the future hydrological response of the watershed. We found that, the basin area with a smaller drought index has small spatial variability of the climate elasticity coefficient. The change in precipitation and underlying surface parameters play a leading role in the change of annual runoff, while potential evapotranspiration was observed to have a little effect. From 2040–2060, runoff changes of different climate models under the RCP4.5 emission scenario displayed spatial heterogeneity compared to the historical period (1970–2000). The study has great significance to clarify the basin hydrological process for future water resource management.

Keywords

• Watershed runoff
• Climate
• Underlying surface
• Budyko
• China