基于SWAT模型的南渡江流域土地利用/覆被变化的径流响应

为了探究热带岛屿性流域土地利用/覆被变化(Land Use/Cover Change,LUCC)的水文效应,以海南岛典型热带岛屿性流域南渡江流域为研究区,构建本地化SWAT模型,模拟流域水文过程及其对LUCC的响应,揭示流域径流的变化规律,对比不同土地利用类型的水文过程及调蓄能力,探讨了典型热带岛屿性流域LUCC的径流效应。结果表明:SWAT模型在南渡江流域的适用性良好,径流模拟对植被蒸散发、产生径流的坡面状况、土壤状况和地下水过程较敏感。不同土地利用类型对流域的产流贡献顺序为耕地>其他林地>橡胶林地; 耕地产流能力最强,其他林地和橡胶林地具有一定的截流蓄水作用。综上所述,与1990年相比,2015年南渡江流域河流径流量减少,流域LUCC导致的地表径流减少是河流径流量减少的直接原因,而蒸散发加剧是地表径流减少的主要原因。

Responses of Streamflow to Land Use/Cover Changes in Nandu River Basin Based on SWAT Model

In order to explore the hydrological effects of land use/cover change(LUCC)in tropical island watersheds, taking the Nandu River Basin, a typical tropical island basin in Hainan Island, China, as the study area, we constructed a localized soil and water assessment tool(SWAT model)to simulate the hydrological process and its response to LUCC, with an aim to reveal the changes of streamflow. The streamflow effects of LUCC could be explored in typical tropical island basin. The hydrological processes and storage capacity of different land use types were compared. The results were summarized as follows. The SWAT model had good applicability in the Nandu River Basin. Streamflow simulation based on the SWAT model was sensitive to vegetation evapotranspiration, slope conditions, soil conditions and groundwater processes. The order of contribution of different land use types to streamflow generation in the basin was tillage land, other forest land and rubber plantation. The strongest flow yield capacity of tillage land was found, while a certain interception and water storage effect were found in other forest land and rubber plantation. To sum up, compared with 1990, the river streamflow decreased in 2015 in Nandu River Basin. The decrease of surface runoff caused by LUCC was the direct reason for the decrease of streamflow, while the increase of evapotranspiration was the main reason for the decrease of surface runoff.