Dynamics and interactions of water-related ecosystem services in the Yellow River Basin, China

Climate change and human activities have profoundly altered ecosystem services in the Yellow River Basin (YRB) since the Grain for Green project was implemented, but have not been accurately revealed on a year-by-year scale. This study combined the InVEST model to reveal the year-by-year changes in the water-related ecosystem services (WRESs) in YRB during 1990–2020, including water yield, soil conservation and water purification services. The trade-off/synergy of WRESs and impacts of land management measures on WRESs were assessed fully. The results showed that from 1990 to 2020, cropland and barren land were considerably converted to forest and grassland in YRB. WRESs were continuously improved as a result of increase of water yield and reductions of soil export and nitrogen export, at rates of +1.11 mm·yr−1, −0.23 t·km−2·yr−1 and −1.01 kgkm−2·yr−1, respectively. We found that in YRB water purification service showed trade-off relationships with soil conservation and water yield services in recent decades, and water yield and soil conservation maintained a synergitic effect. Additionally, the revegetation measures showed a potential of enhancing soil conservation and water purification, but reducing water yield. This study provided a thorough understanding of WRESs dynamics and a valuable reference for the ecological restoration practices.