Characterization of hydrological response of the Dawen River Basin under land use change

Abstract

Land use change is one of the dominant drivers of hydrological change in the basin. Assessing the hydrological responses to land use changes is crucial for sustainable water resource management. We focused on the Dawen River Basin to analyze land use dynamics from 1985 to 2021. Using the SWAT model, we assessed hydrological responses under various land use scenarios, quantified impacts on hydrological elements, and employed the Random Forest Method to evaluate the impact of different land use types on runoff. Results show that from 1985 to 2021, cropland and grassland in the watershed decreased by 11.57% and 52.04%, respectively, while forest land and construction land increased by 11.45% and 103.85%, respectively; other land types showed no significant changes. These land use changes resulted in an increase in watershed evapotranspiration by 26.53 mm, a decrease in groundwater recharge by 19.64 mm, and an increase in surface runoff depth by 18.94 mm. Cultivated land, forest land, and grassland were identified as the major influencers on watershed runoff, with importance weights of 1.0729, 0.9607, and 0.8305, respectively. The variations in hydrological elements within the Dawen River watershed during the study period were primarily associated with the reduction in cultivated land and grassland area, coupled with an increase in constructed land area.