مقايسه مدلهاي تحليل منطقه اي سيلاب و بارش رواناب در شرق استان هرمزگان

Comparison of regional flood frequency analysis and rainfall-runoff simulation for the eastern coastal part of the Hormazgan province

In spite of frequest flood events in the eastern part of Hormozgan province, appropriate flood records are not available. There are many rivers that are ungauged at all or have very scares data. To estimate flood peaks at ungauged sites, two different hydrological model structures namky, the statistical and the conceptual models are applied and evakuated. The statistical models included in the study are Index Flood (based on Gumbel and Log Normal distributions) and Generalized Extreme value (GEV) regional distribution. The HEC-1 is selected among the existing conceptual models. The selected models are applied to the study area and the obtained results are compared with the flood frequency analysis of the existing stations. Furthermore, recommendations are made for the advantages and disadvantages of the methods. Among the first series of the model, the GEV performed better than the other methods. However, when compared with the second series(HEC-1), both of the hydrological model structures showed that each one has their own advantages and disadvantages. Therefore, it was not possible to select any of them as a preferable model for the entire region. To be in a safe side, it is more convenient to apply both of the models, simultaneously. Also, in order to increase the accuracy of flood quantiles, the results of flood frequency analysis of nearly gauged catchments to be used for indicating proper model.