Numerical simulation of the effects of stream seepage on flood routing

To study the effects of stream seepage in arid and semiarid regions, a flood routing mathematic model is developed based on the basic stream flood water motion equations which are discretized and solved using the Preissmann four-point linear implicit scheme. At the same time, flood routing is simulated for a prismatic stream under the effect of seepage. The test results show that stream seepage has effect on flood routing. As discharge decreases, the water level falls and the peak value at the same section is postponed. Such effect becomes more obvious as the infiltration rate increases. Change in the stream bottom slope has little effect on flood routing. This paper provides a feasible method for flood routing simulation for ephemeral streams in arid and semiarid regions.