Simulation of Rainfall-Runoff Process in a Catchment with a Check-Dam System Equipped with a Perforated Riser Principal Spillway on the Loess Plateau of China

Check dams are applied worldwide as an effective approach for soil and water conservation. To improve the simulation accuracy of the hydrological processes in a catchment with a check-dam system, this study analyzed the applicability and accuracy of a formula for the drainage process of a perforated riser principal spillway based on observational experiments. The rainfall-runoff processes in a catchment with a check-dam system were also simulated with the recommended formulas for the drainage process of a perforated riser principal spillway. The deviations in the calculated discharge from the observed values of the experiment with the recommended formulas under normal and abnormal working conditions were within +/- 15% and +/- 5%, respectively. The hydrologic model used in this study needed only a few parameters to achieve a satisfactory simulation accuracy. The recommended formulas for the drainage process of a perforated riser principal spillway can improve the simulation accuracy of a flood peak by 7.42% and 19.58% compared with the accuracies of the technical code formula scenario and no drainage scenario, respectively. The results of this study are expected to provide a reference for flood warnings and safe operations of check-dam systems.