Research on river velocity and flow estimation based on scalar transport equation

ABSTRACT River flow measurements are of great significance for flood prevention. Traditional immersion measurement methods not only consume manpower and material resources but are also greatly affected by the environment. Non-immersion image flow measurement methods have attracted widespread attention owing to their simplicity and safety. This paper proposes a flow measurement algorithm based on the scalar transport equation. Combining the scalar transport equation with fluid mechanics is more consistent with hydrodynamic characteristics and provides a better physical basis than other methods. Simultaneously, to calculate the two-dimensional velocity vector, it is assumed that the 3 × 3-pixel area at the speed measurement point exhibits exactly the same motion trend between two adjacent frames. Because only a few key speed measurement points are calculated, the calculation time of this method is significantly reduced compared with other methods. To verify the feasibility of the algorithm, two rivers at hydrological stations were selected to estimate their flow. The experimental results show that the total flow error of the proposed method is only 3.29 and 2.79% compared with the total flow measured by the current meter, which is a significant improvement over other methods.