气候变化情景下黄河水源涵养区水源涵养量预测及不确定性分析OA

This study analyzed the spatiotemporal characteristics of water conservation capacity of the Yellow River water conservation area from 1980 to 2023 using the InVEST model.Six optimally selected CMIP6 Global Climate Models(GCMs)under three Shared Socioeconomic Pathways(SSP1-2.6,SSP2-4.5,and SSP5-8.5)were integrated to project water conservation capacity for the near future(2026-2035)and the distant future(2036-2050).The uncertainty of projections was quantified through a triple-source"internal variability-model-scenario"decomposition approach.The results indicate that the multi-year average water conservation of the study area during 1980 to 2023 was 25.11 mm,exhibiting an overall increasing trend with an abrupt change in 2002(post-change increase rate is 8.75%).Spatially,water conservation was characterized by higher values in the southwest and lower values in the northeast.Baseline precipitation averaged 557.4 mm with an increasing trend.Future precipitation under SSP1-2.6 and SSP5-8.5 scenarios slightly exceeded baseline levels,while SSP2-4.5 was slightly lower than the baseline.Projections from the six CMIP6 GCMs diverged significantly.All GCMs indicated increasing water conservation under SSP1-2.6,while SSP5-8.5 exhibited the largest fluctuations.The projected increase under SSP2-4.5 was slightly lower than under other scenarios.The areas with the highest values are located in the Yellow River source area,followed by the Tangnaihai-Lanzhou area,while the Wei River-Yiluo River basin has the lowest values.GCMs uncertainty constituted the primary source of projection uncertainty,followed by scenario uncertainty,with internal variability having minimal impact.Total fractional uncertainty was greater in the long term than in the near term of future.