Determining the effect of physical characteristics on flood hydrograph (Case study: Western section of Jazmurian Basin)

Abstract Flood causes great and uncompressible damage to people’s life and properties as well as environment each year in Iran. This research was carried out at the west section of Jazmurian basin that placed in the southeast of Iran. In this research physical characteristics such as area (A), perimeter (Pr), average elevation of basin (av.e), average slope (av.s), gravelious coefficient (G), length of main stream(L), pure slope of main stream(Pur), Lc, Tc and Tl for independent variables and hydrograph component such as Qp, Q25, Q50, Q75, Tp, T25, T50, T75 and Tb for dependent variables were used. For this the data of 12 hydrometric stations were used. Normality test was done by kolmograph- Smironov. After that using two and multiple variables regression analysis and with the use of modeling, the relation between dependent and independent variables were defined. The evaluation of hydrologic model behavior and Performance is commonly made and reported through comparisons of simulated and observed variables. Frequently, Comparisons are made between simulated and measured stream flow at the catchments outlet. Significant models are included the models that have correlation coefficient bigger than 0.325 at 1 percentage level and bigger than 0.250 at 5 percentage levels. We used three criteria such as RMSE, RE and CE for selecting the ultimate models. These models have less RMSE and RE and more CE .The results approve that with the use of physical characteristics of the basin we can determine the synthetic hydrograph. The results also show that the two- variable models have higher efficiency in estimating the discharge variables of the simulated hydrographs