چکیده:
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.
خلاصه ماشینی:
Keywords : Physical attributes; Hydrological modeling; Synthetic hydrograph; Dependent variable; Jazmurian basin; Iran 1.
Empirical formulas, Synthetic hydrograph, simulation methods, statistical estimation of maximum instantaneous are analyzed and flood indicator are used for supplying maximum of instantaneous flood in those watersheds without hydrometric station.
Location of hydrometric stations in the study area Peak discharge, base time, discharges of 25%, 50% and75% of the peak, time to peak, the times corresponded to discharge of 25%, 50% and 75% that are important component of hydrograph (Snyder 1938 Gupta et al, 1986) were selected for developing hydrologic models.
Two and multiple regression, were used to determine relationships between dependent and independent variables with the intention of determination and assessment of main factors controlling hydrograph components and also homogeneity of accepted stations.
For achieving final models of each dependent variable, important assessment criteria such as adjusted coefficient of determination (adjusted R2), relative error of estimation and approval (RE), residual mean square error (RMSE) and finally coefficient efficiency (CE) were used (Formula 1-3).
Evidently in equal condition, the models with more adjusted coefficient of determination, less estimation and approval error and less number of independent variables were selected as the best models.
ultimate regression models for estimation of hydrograph, s component Dependent Residual Figure 3 shows relation of estimated maximum discharge by connected model with perimeter of different stations in studied watershed.