基于曼宁公式影响因子相关分析的洪水流量计算——以洮河流域为例

Flood flow calculation based on correlation analysis of Manning formula: a case study of Taohe River Basin

为解决采用曼宁公式法推求洪水流量时,主要影响因子比降和糙率选用任意性较大的问题,以西北地区洮河流域8个水文站为研究对象,首先对各站选用断面数据进行单值化处理;然后探索建立了影响因子水位-比降、水深-糙率之间的相互关系;其次模拟推求了洪水流量,并对推求结果进行了误差分析、应用范围和预警指标确定;最后通过相应级别预警指标历史出现次数和典型年洪峰级别对预警指标阀值进行了验证。结果表明:采用曼宁公式主要影响因子相关关系推算洪水流量的方法是可靠的,满足规范精度要求。该方法能够迅速推算出洪水流量,可为水文应急监测工作提供一定参考。

In order to solve the problem of large arbitrariness in the selection of major influencing factor ratio and roughness when using Manning Formula method to calculate flood flow, 8 hydrographic stations in Taohe River Basin in northwest China were studied.Firstly, the selected section data of each station was processed by uniformization, then the relationship between influencing factors water level and gradient, water depth and roughness are explored and established.Secondly, the flood flow is simulated, the error is analyzed, and the application scope and early warning index of the calculation results are determined.Finally, the threshold value of early warning indicators is verified by the historical occurrence times of early warning indicators of corresponding levels and typical annual flood peak levels.The research results show that the method of using the improved main influence factors to calculate the flood flow is reliable.This method can quickly calculate the flood flow, it can also guide the flood emergency monitoring work.