Numerical Prediction of Runoff Load of Suspended Solids under a Rainfall Condition by Lumped Model

Abstract

 For the water quality management toward a closed water area, reduction of pollutant load from source distributed over its watershed is recently becoming important. In this study, to predict and estimate the amount of pollutant runoff under a rainfall condition, lumped model was developed and applied to four rivers which are flowing into Isahaya regulation pond. In this model, the process on rainfall-runoff was computed by the runoff function method, and the pollutant runoff was calculated using specific discharge. In the model application, temporal variation of suspended solids (SS) was predicted. From the comparison between observed and calculated results, it is shown that the temporal variations of flood discharge and runoff load of SS were estimated by the developed model with acceptable error.