基準化パウエル法の適用によるタンクモデルの同定

Several problems have been examined to discuss the hydrological effects of large natural reconstruction by land reclamation in natural slope by applying the series tanks model. The data used are the observed ones of rainfall and runoff in the Uchida basin of 0.107<km>^^^2. The Standardized Powell method proposed by Nagai and Kadoya is applied and examined to the parameter identification of series tanks model with sixteen unknown parameters for the flood runoff and long term runoff analysis. The Chi-square criterion is used as the objective function for the purpose of finding a set of optimum parameters of the series tanks model. It is pointed out that the calculated hydrograph using the model parameter identified by the Standardized Powell method agrees fairly with the observed hydrograph for the flood runoff analysis. However, it is clarified that the reproducibility of the observed hydrograph in a smaller flood runoff is not sufficient in the case of applying the optimum parameter identified for the large flood runoff. Next, the series tanks model by applying the Standardized Powell method is identified to the long term runoff with the daily data of precipitation and runoff. As the result, it is found that the agreement of the observed data and calculated ones is good in the period of high water season and not sufficient in the low water season. Finally, it is pointed out to be worthwhile subject to investigate how the model parameters will be changed with the spread of land reclamation area in the hilly watershed.