基于流域形态的山丘区小流域河道宽度计算方法

Calculation Method of River Width of Mountainous Watershed Based on Watershed Morphology

山洪灾害防治及山洪预警预报工作都需进行山丘区河道洪水演算,而如何确定山丘区小流域的河流宽度是山洪演进计算中的关键问题之一。为了能够正确选择河宽概化公式,提出采用修正后的河流发育系数Kw来反映流域形态,以此作为选择指标进行公式优选。通过对全国2省市6个山丘区小流域的404个实测河道断面数据进行分析,提出了一套以流域面积和河流发育系数为标准的河流宽度计算方法。在山西省北张店流域和湖南省清水站流域的验证结果表明,该河流宽度计算方法精度较好,可为山洪预报提供计算支持。

The calculation of river floods in mountainous and hilly areas is crucial for mountain flood prevention and forecasting.However,how to calculate accurately the river width in the mountainous and hilly areas has become a key issue in the calculation of mountain floods.This paper takes the modified river development coefficient Kw which reflects the watershed morphology as a selection indicator for the best generalized formula for river width,and proposes a river width calculation method based on watershed area and river development coefficient by analyzing the measured section data of the rivers of 6 mountainous watersheds in 2 provinces.After being verified in Beizhangdian Watershed in Shanxi Province and Qingshuizhan Watershed in Hunan Province,the results indicate that the accuracy of this calculation method for river width is better,which can provide the calculation support for mountain flood forecast.