Single-Valued Calculation of the Relationship Between Water Level and Discharge by Using Saint-Venant Equation
LI Jie;CHEN Junying;SU Xiao;LI Yong;LIU Chang;Hanjiang River Hydrology and Water Resources Survey Bureau of the Yangtze River Water Conservancy Committee;College of Water Resources and Architectural Engineering,Northwest A&F University;
The relationship of water level and discharge is very important for hydrology prediction,hydrology data collection and hydrology basic research. It's necessary to find a simple and high precision computed method. It's very difficult and expensive to get the discharge in the river. In order to get the discharge from the observed water level,this paper put forward the single-valued calculation of the relationship between water level and discharge with and without water gradient by combining continuity equation,momentum equation of Saint-Venant system of equations and Satang formula. It took the cross section of river as a rectangular cross section and derived the rope-shaped discharge equation with not neglect inertia item in different slope. This paper provided the calculated steps. These discharge equations was verified by the measured data of Baihe Station. The results show that the given equation theory of flow-stage is correct. It is also simple and high precision. This discharge equation can be used in practical work.