中文摘要：

设计洪水是确定水利工程建设规模，设计防洪工程的重要依据，对桥涵、堤防及水库等研究具有重要的影响。在半干旱无资料的某些中小流域，如何在混合产流模式下的无资料地区推求设计洪水，是当今计算洪峰流量所面临的最新难题。通过在Google地球软件上量取半干旱流域的干旱区和湿润区的面积，采用汇水面积相关法、综合参数法、推理公式法、瞬时单位线法分别计算干旱区和湿润区的洪峰流量，并将两种产流模式下的洪峰流量按干旱区与湿润区的面积比进行加权平均，可得该流域在混合产流模式下的设计洪峰流量；最后对比分析了4种方法计算的洪峰流量。结果表明，推理公式法是半干旱无资料中小流域推算设计洪水的最优方法。

英文摘要：

Design flood is an important basis for determining the scale of hydraulic eng qineering construction and designing flood control engineering. It has significant influence on the study of bridge, embankment, culvert and reservoir. In the semi-arid and non-data basin in a small scale, how to calculate design flood in the non-data area under the mixed flow through Google Earth model is the newest problem. In this paper, by measuring the area of arid and humid basin software and calculate the flood peak flow in the arid and humid areas using catchment area method, comprehensive parameter method, rational method and instantaneous unit hydrograph method. These two kinds of peak flows calculated by above methods were weighted averaged according to the area ratio of the arid and humid areas. The result is the design flood peak flow under the mixed flow model. By comparing and analyzing flood peak flow calculated from these four methods, the results show that the rational method is the best way to cal- culate the design flood in the semi-arid and non-data basin in a small scale.