Method and system for measuring hill-slope shallow water flow velocity with realistic boundary condition of electrolyte tracer

The measurement of shallow water flow velocity is significant to hydrological process. A pulse function was used as boundary condition for the analytical solution so as to estimate shallow water flow velocity with relatively high errors. In this study, an additional sensor was added at the location close to the salt injection to register the actual boundary function. The measured boundary condition data were used to estimate the parameters of the boundary condition. Then the shallow water flow velocity was determined by using the least square method. The experimental results indicated that the velocities computed by the two realistic boundary condition methods showed no significant difference, and they agreed also with those measured by the volumetric method. Especially, at short distance, the realistic boundary condition methods had higher accuracy than the pulse method. Thus the realistic boundary condition method and system could be a feasible way to measure water flow velocity.