Evaluation of the contributions of climate change and overgrazing to runoff in a typical grassland inland river basin

Study region: The Xilin River Basin in the Inner Mongolia Autonomous Region, China. 

Study focus: This study aims to identify the components and change patterns of runoff in the basin, and quantitatively assess the impacts of climate change and overgrazing on runoff. Future changes in river basin runoff were simulated under three climate change scenarios. 

New hydrological insights for the region: This study quantitatively assessed the impacts of climate change and overgrazing on runoff in the Xilin River Basin using the HYPE model and five attribution scenarios. The assessment results are as follows: (1) Monthly runoff in the basin shows typical bimodal characteristics. Snowmelt is the primary contributor to runoff from March to mid-April, while precipitation has the largest contribution in the remaining months. (2) During the growing season, overgrazing has a more significant impact in reducing runoff than climate change, and runoff changes caused by climate change are more complex on a monthly scale than at the annual scale. (3) Among the three development scenarios, SSP126 with low levels of greenhouse gas emissions appeared to be the most suitable for the sustainable and healthy development of the grassland inland river basin.