陇南地区桥涵小流域设计洪水计算

Calculation of Design Flood in Small Watershed of Bridge and Culvert in Longnan Area

小流域洪水具有产流快、峰量大、预测难度大、破坏性强等特点。而目前我国尚无准确的城区小流域设计洪水计算方法。对于城区小流域设计洪水计算通常采用规范的推理公式或城建部门的经验公式近似计算,存在一定的误差。结合城区的特点,通过暴雨推理法、径流形成法及城建经验法比对,确定陇南某城区小流域设计洪水,认为按径流形成法计算30km2流域面积以内的洪水量较为合理。

The flood in small watershed has the characteristics of quick runoff, high peak, difficult to predict and serious destructive effect. There is no accurate calculation method of design flood in small watershed of urban areas in China. The calculation of design flood in small watershed of urban area usually applies the normative reasoning formula or the experience formulas of city construction departments for approximate calculation. There are a certain errors. Combining with the proper features of city and comparing the rainstorm reasoning method, the runoff formation method and the experience method of the city construction department, the paper determines the design flood of small watershed in an urban area of Longnan. It is more reasonable to calculate the flood flow within 30Km2 watershed according to the runoff formation method.