Spatiotemporal pattern and influencing mechanism of the flood-regulating ecosystem service capacity and demand in China?s Yellow River basin, 2000-2020

Study region: The Yellow River basin (YRB), China.Study focus: To alleviate flood risks and safeguard human well-being, understanding the spatio-temporal pattern of and factors influencing flood-regulating ecosystem service capacity and de-mand relationship is crucial. This study quantifies the capacity-demand ratio and identifies the regions where capacity did not meet demand from 2000 to 2020. The spatial Durbin models (SDM) were employed to detect the spillovers and assess the direct and indirect effects of factors influencing the capacity-demand relationship in the YRB and across different reaches.New hydrological insights for the region: The results show that regions with unmet demand has increased since 2000 due to a dramatic increase in demand and a reduction in capacity in the YRB. The SDM results reveal that wetlands and forests had positive direct effects, and cropland and built-up land had adverse effects on the capacity-demand ratios. Heterogeneity tests show that wetland, forest and low-coverage grassland were the biggest contributors to the capacity -demand ratios across upper-, mid-and downstream areas, respectively. Forest in the upper reach had positive direct effects and spillovers on the capacity-demand ratio. Cropland and low -coverage grassland negatively affected the capacity-demand ratio in the middle reach. The capacity-demand relationship in the lower reach needs to be improved by restoring ecologically functional land and enhancing the capacity of artificial hydro facilities.