RCP8.5情景下流域景观水文与泥沙动态连通变化研究

在气候变化背景下，水文连通是风景园林学学科中景观水文研究的热点和重点之一。目前的景观水文连通研究多基于静态地表，而忽略地表演化过程，尤其是河底泥沙动态变化。在总结现有水文连通研究的基础上，结合气候预测模型、水动力地表景观演变模型及景观连通指数研究方法，以英国赛文河凯尔苏斯流域为研究区，采用UKCP18气候模型预测RCP8.5情景下未来10年间(2021—2030年)日降雨量，运用凯撒二维水动力地表景观演变模型(CAESAR-Lisflood)模拟10年连续河流演化及淹没模式变化，基于景观连通指数评价流域景观水文的动态连通变化。结果表明：泥沙变化对淹没模式和水文连通性产生影响，未来10年间整体连接度(IIC)与可能连通性(PC)变低，雨季水文IIC与PC变化幅度较大，旱季平稳。凯尔苏斯流域洪泛区域比河道的沉积作用更明显，流域总沉积量是侵蚀量的4.6倍。泥沙输移作用使得淹没面积减少0.25km2、流域总水量减少40%，水文IIC与PC降低

Study on Dynamic Connectivity of Landscape Hydrology and Sediment in Watershed under RCP8.5 Scenario

In the context of climate change, hydrological connectivity is one of the hot spots and emphases of landscape hydrology research in landscape architecture. At present, most studies on landscape hydrological connectivity are based on static land surface, but ignore the evolution of land surface, especially the dynamic changes of river sediment. On the basis of summarizing the existing researches on hydrological connectivity, climate prediction model, hydrodynamic landscape evolution model and landscape connectivity index are combined. Taking the Caersws of the Severn River in England as the study area, the UKCP18 climate model was used to predict the daily rainfall in the next ten years (2021-2030) under the RCP8.5 scenario, and the Caeser-Lisflood model was used to simulate the decadal continuous river evolution and inundation pattern changes. The dynamic connectivity of landscape hydrology was evaluated based on the landscape connectivity index. The results show that sediment changes have an impact on inundation patterns and hydrological connectivity, and the overall Integral Index of Connectivity (IIC) and Probability of Connectivity (PC) will decrease in the next decade, the hydrological IIC and PC will change greatly in rainy season, and be stable in dry season. The deposition of flood area is more obvious than that of river channel, and the total deposition is 4.6 times of erosion. The inundation area decreased by 0.25km2, the total water amount decreased by 40%, and the hydrological IIC and PC decreased