基于CMIP6和VIC模型的湘江流域未来水文过程变化预测

Projection of Future Hydrological Process Variations in the Xiangjiang River Basin Based on CMIP6 and VIC Models

摘要: 随着全球气候变化的加剧，其对流域水文过程的影响日益显著。湘江流域作为中国南方重要的水资源区域，其径流变化不仅直接影响区域水资源的可持续利用，还对生态安全和社会经济发展具有深远意义。本研究基于VIC (Variable Infiltration Capacity)水文模型，结合第六次国际耦合模式比较计划(CMIP6)气候模式数据，系统预测未来变化情况。研究结果显示，湘江流域未来时期(2020~2099年)的气候及径流变化在时间和空间尺度上均表现出显著特征。年际尺度上，在SSP2-4.5 (中等排放情景)和SSP5-8.5 (高排放情景)下，未来时期降水量和平均温度均呈现增加趋势，且高排放情景下增幅更为显著；径流量在两个情景下均显著增加，中等排放情景下增幅更大。年代尺度上，2020s、2030s和2060s为降水与径流枯水期，2040s、2050s、2070s、2080s和2090s则为丰水期。SSP2-4.5情景下极端降水和径流事件可能集中在2040s、2080s和2090s，而SSP5-8.5情景下则可能出现在2040s和2070s；径流量时间分布与降水变化高度一致，进一步验证了降水是径流变化的主导驱动因子，湘江流域未来径流变化主要是由降水引起。这些研究为未来流域水资源管理和自然灾害预防提供了重要参考。

Abstract: With the intensification of global climate change, its impacts on hydrological processes in river basins are becoming more and more significant. As an important water resource region in southern China, the runoff changes in the Xiangjiang River Basin not only directly affect the sustainable utilization of regional water resources, but also have far-reaching significance on ecological security and socio-economic development. This study is based on the VIC (Variable Infiltration Capacity) hydrological model, combined with the climate model data from the Sixth International Coupled Model Intercomparison Program (CMIP6), to systematically predict future changes. The results show that the climate and runoff changes in the Xiangjiang River Basin in the future period (2020~2099) exhibit significant features at both temporal and spatial scales. At the interannual scale, both precipitation and mean temperature show increasing trends in the future period under SSP2-4.5 (medium emission scenario) and SSP5-8.5 (high emission scenario), and the increase is more significant under the high emission scenario; runoff increases significantly under both scenarios, and the increase is greater under the medium emission scenario. On the chronological scale, the 2020s, 2030s, and 2060s are dry periods for precipitation and runoff, and the 2040s, 2050s, 2070s, 2080s, and 2090s are abundant periods. Extreme precipitation and runoff events are likely to be concentrated in the 2040s, 2080s, and 2090s under the SSP2-4.5 scenario, and the 2040s, 2080s, and 2090s under the SSP5-8.5 scenario 2040s and 2070s. The temporal distribution of runoff is highly consistent with precipitation changes, which further verifies that precipitation is the dominant driving factor of runoff changes, and future runoff changes in the Xiangjiang River Basin are mainly caused by precipitation. These studies provide important references for future water resource management and natural disaster prevention in the basin.