变化环境下韩江生态流量演变特征分析

选取位于粤东、闽西南地区的韩江流域为研究对象，基于CA-Markov模型对2050年流域土地利用空间格局进行预测，构建SWAT分布式水文模型，以未来土地利用情景和气候变化情景为变量进行水文模拟，分析不同情景下韩江生态流量的时空演变特征。结果表明，未来城镇化扩张将使梅江支流中上游成为韩江流域内生态流量对土地利用变化最为敏感的区域；土地利用和气候变化将导致韩江流域枯水期流量整体减小，枯水期流量对环境变化更加敏感；韩江流域生态流量变化特征将呈现从西南到东北由升到降的趋势，梅江支流中上游地区的生态流量将得到改善；梅江和汀江两大支流上游区域生态流量对气候变化更为敏感；韩江流域径流总量下降，但丰枯流量分化加剧，长期来看枯季生态流量保障风险可能进一步增大。

Analysis on evolution characteristics of ecological flow of Hanjiang River under changing environment

Taking the Hanjiang River basin located in eastern Guangdong and southwest Fujian as the research object, the spatial pattern of land use in the basin in 2050 was predicted based on CA-Markov model. The SWAT distributed hydrological model was constructed, and the hydrological simulation was carried out with the future land use scenario and climate change scenario as variables to analyze the temporal and spatial evolution characteristics of ecological flow of Hanjiang River under different scenarios. The results show that the future urbanization expansion will make the middle and upper reaches of the Meijiang River become the most sensitive area of ecological flow to land use change in the Hanjiang River Basin. Land use and climate change will lead to the overall decrease of flow in dry season of the Hanjiang River Basin, and the flow in dry season is more sensitive to environmental change. The change characteristics of ecological flow in the Hanjiang River Basin will show a downward trend from southwest to northeast, and the ecological flow in the middle and upper reaches of Meijiang River will be improved. The regional ecological flow in the upper reaches of Meijiang River and Tingjiang River is more sensitive to climate change. The total runoff of the Hanjiang River Basin decreases, but the differentiation of flow in dry season and wet season intensifies. In the long run, the risk of ecological flow guarantee in dry season may further increase.