Resumen
The ecological restoration projects in the Loess Plateau (LP) has significantly altered the underlying surface conditions, coupled with a warming?wetting climate, which has profoundly affected the regional water cycle. Evaluating the response of runoff to external environmental change and quantitatively identifying the contribution of anthropogenic interference and climate change are prerequisites for efficient utilization of water resources in arid/semi-arid regions. Daily recorded data of hydrological and meteorological elements between 1969 and 2019 and the elasticity coefficient method based on Budyko hypothesis were used for attribution analysis of runoff change in the Yanhe River basin. The results show the following: (1) the measured runoff decreased significantly (p < 0.05, ?0.2845 mm year-1), and suggested substantial difference before and after 2000; (2) the area of woodland and grassland had a sharp increase from 2000, while the elasticity of runoff to precipitation, potential evapotranspiration (ET0), and vegetation all decreased; (3) the improvement of underlying surface conditions has become the leading factor of runoff reduction with a contribution of 96.78%; (4) the impact of vegetation restoration on runoff reduction is effective within a certain threshold. We consider that more attention should be paid to the afforestation scale and its possible negative eco-hydrological effects in future ecological restoration.