基于栅格分布式水文模型并结合GIS技术，进行东江流域白盆珠水库子流域下垫面变化的洪水响应分析。根据该流域现状土地利用情景分析方法构建9种流域下垫面情景，选取大、中、小3场典型洪水过程，定量分析下垫面变化造成的洪水响应。结果表明：林地及其空间分布在截留降雨、消减洪峰和延缓洪峰滞时方面效果明显，故保护林地，特别是沿河道及流域上游的林地，对流域防洪减灾有重要意义；城市化有增加产流和加快汇流的作用，对流域防洪非常不利；水利工程有效地控制流域内支流洪水，对流域防洪有积极的意义；下垫面的变化对小洪水的影响大于大洪水。深入研究白盆珠水库流域下垫面变化引起的洪水响应将对流域防洪减灾有重要意义。

In association with GIS technology, grid-distributed hydrological model is used to study the flood response caused by underlying surface change in the sub-basin of Baipenzhu reservoir in Dongjiang River basin. In light of the status quo of land use in this basin, 9 underlying surface scenarios are built by scenario analysis, and three typical floods respectively of large, medium, and small scale are chosen to quantitatively analyze the flood response caused by underlying surface change. It is found that forestry and its spatial distribution can effectively retain rainfall, reduce flood peak, and postpone flood peak lag time. In this sense, the protection of forestry, in particular, forestry along the river channel and in the upper reaches of the basin, is significant for the flood control and disaster mitigation in the basin. Moreover, since urbanization will increase runoff yield and speed up confluence, which is detrimental to flood control, hydropower projects are of great help by controlling floods in tributaries of the basin. Response of big floods caused by underlying surface change is greater than that of small floods.