区域水平衡分析是保证水资源可持续利用和经济可持续发展的基础。在介绍CPSP模型计算原理的基础上，选择 该模型作为北京市大兴区的区域水平衡分析工具。利用《北京市大兴区水资源综合规划》（2004年）中径流量的计算成 果、遥感ET及地下水实测数据对模型进行校验结果表明，模型径流计算结果与规划成果基本一致，模型能较好模拟腾发 及地下水储量动态变化过程。现状分析表明：2004年缺水0.72亿m3，2005年缺水1.80亿m3。

Regional water balance analysis is the foundation that will guarantee the sustainable and scientific use of water resources and the sustainable development of the economy. In this study, the CPSP hydrological model is selected as the regional waterbalance analysis tool for Daxing District. The model is validated with the 3 types of data as the runoff data from the Integrated Planning of Water Resource in Daxing District of Beijing, the evapotranspiration data estimated by remote sensing-based model (RS-ET), and the groundwater monitoring data, respectively. The calculated runoff data are basically consistent with that of the Integrated Planning of Water Resource in Daxing District, Beijing. Meantime the dynamic variation of evapotranspiration (ET) and groundwater reserves are better simulated by the CPSP hydrological model. Serving as the basis for this study, the current water resources for 2004 and 2005 are evaluated, in which the water shortages are 0.72×108 m3 and 1.80×108 m3, respectively.