Quantifying the effect of vegetation change on regional water balance within the Budyko Framework

Abstract:

Budyko framework is widely used to investigate impacts of climate and landscape changes on regional hydrology, but quantifying the effect of vegetation change is still a challenge due to the lack of an explicit expression of vegetation change in Budyko equations. This study attempts to establish a relationship between the change of landscape parameter in a Budyko equation and the change of vegetation (represented by NDVI) in Yellow River Basin and Hai River Basin of China, where vegetation and regional hydrology changed significantly during the past 30 years. It is found that the ratio of landscape parameter change to NDVI change has a good relationship with the aridity index, and thus vegetation change can be converted into landscape parameter change. Then the NDVI elasticity of runoff is introduced and formulized under the Budyko framework. It provides a useful tool for quantitative evaluation of regional hydrological response to vegetation change.