Abstract
Recently in Okinawa, red soil runoff becomes a remarkable problem, and its prediction models are demanded. In this study, a purpose is a construction of the models which can calculate a time series of suspended sediment concentration using rainfall data. First, the LQ equation is often applied in basin scale suspended sediment runoff analysis. The equation has been improved to express some sediment runoff characteristics which can not be expressed by the LQ equation. As results of the application of the improved LQ equation, it was confirmed that every improvements were effective for the representation of each characteristic. Next, the suspended sediment runoff model was constructed including the improvements above. A rainfall-runoff process was based on the storage-typed runoff model which can separate direct and base flow. A sediment runoff process was composed of the detachment process of soil particles by raindrops and the storage process of detached soil particles. This model was applied in Yakashimoguchi river basin for 2 months. It was recognized that the model represented a time series of suspended sediment concentration accurately.
