A bivariable coupling model for river channel routing developed from the flow continuity equation and its application

Wei Si,Weimin Bao,Yanping Cui,Hui Yu,Senlin Wang,Zhixing Niu

doi:10.4314/wsa.v45i2.06

Wei Si, Weimin Bao + Show 4 more

Open Access

https://doi.org/10.4314/wsa.v45i2.06

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Abstract

In this study, a bivariable coupling model for river channel routing is presented. The proposed model is developed from the Priessmann 4-point implicit differential scheme with a weight coefficient of river flow continuity equation. It is based on the transformation of two different expression forms of river channel storage equation. Furthermore, we consider the impact of lateral inflow along the study river channel from another perspective. In this paper we deduct lateral inflow from the lower section instead of adding lateral inflow to the upper section. In order to be representative of geographical range, river channel characteristics, flood magnitude, hydraulic characteristics and time, the proposed model is tested in 38 river channels of 6 river systems in China by using observed data during flood season. The rationality of model structure and the validity of model simulation are examined comprehensively. Comparison between the proposed model and Muskingum model shows that the proposed model can improve the simulation accuracy. The results show that the simulation accuracy and stability of the bivariable coupling model is much better than that of the Muskingum model.

Highlights

Flood forecasting based on hydrological models is an important non-engineering measure for flood control and disaster reduction, which has received increasing attention from public, government and academic communities (Al-Safi and Sarukkalige, 2017; Yu et al, 2014)
There are many methods for flood routing, which are mainly divided into two categories: one is the hydraulic method based on Saint-Venant equations (Molls and Molls, 1998); another is the hydrologic method based on the water balance equation and river channel storage equation (Kubo, 1985)
In order to solve the abovementioned problem relating to the Muskingum routing model, we propose a bivariable coupling model of universal applicability for river channel routing in this work

Summary

Introduction

Flood forecasting based on hydrological models is an important non-engineering measure for flood control and disaster reduction, which has received increasing attention from public, government and academic communities (Al-Safi and Sarukkalige, 2017; Yu et al, 2014). In order to consider the non-linear relationship between river channel storage and outflow, structural improvement of the Muskingum routing method is mainly about the nonlinearization of a linear storage-release relationship and the study of model structure simplification (Kumar et al, 2011; Ponce, 1979).

Results

Conclusion