Modeling the impact of climate change and vegetation conversion on water budget: A case study in the Loess Plateau of China

Study region: A typical grassland (Medicago sativa plot) and a typical forest land (Robinia pseudoacacia plot) located in the semi-arid Loess Plateau, China.Study focus: Field observations and scenario simulation approaches were used to investigate the potential impact of future warming and drying climate on the whole water budget and to assess whether, how, and to what degree the highly recommended man-driven tree-to-grass conversion could alleviate the adverse impact of such climate change on soil water. New hydrological insights for the region: Differences of interception and transpiration between two plots resulted in their different soil water storage. Under the warming and drying future climate, interception and transpiration in two plots would experience significant reductions, especially transpiration, and M. sativa plot could maintain more water than R. pseudoacacia plot. When R. pseudoacacia was replaced by M. sativa, although interception would dramatically increase, the transpiration would significantly decrease, which made the soil water storage experience an insignificant change. Climate change and tree-to-grass conversion mainly exerted their influences in months with larger precipitation, and vegetation conversion would reduce monthly T/ ET. Our study improves the understanding of the hydrological processes under climate change and vegetation conversion, and also provides valuable guidelines for the management of water resources and the restoration of ecological environment in the semi-arid Loess Plateau.