Comparison of the accuracy of the Modified At-kin and the Convex methods in flood routing in a Dalaki River reach

Subject Areas : watere sciences

Masoud Mesbahi ¹ (Department of Civil Engineering, Faculty of Engineering, Arsanjan Branch, Islamic Azad University, Arsanjan, Iran)
Majid Abbasizadeh ² (Assistant Professor, Department of Watershed Management, Faculty of Agriculture and Natural Resources, Arsanjan Branch, Islamic Azad University, Arsanjan, Iran)
Mohammadreza Nikmanesh ³ (Assistant Professor, Department of Civil Engineering, Faculty of Engineering, Arsanjan Branch, Islamic Azad University, Arsanjan, Iran)

Received: 2023-06-03 Accepted : 2023-10-06 Published : 2023-05-22

Keywords: Dalaki River, RMSE, flood routing, At-Kin method, Convex method,

Abstract :

In this research, using two hydrological methods, convex and At-Kin, the flood routing was investigated in the Sarqanat and Kalel reach located in the Dalki River. To perform this operation, 26 flood hydrographs were selected as input to the model. and the output hydrographs of the models were compared to the observed output hydrograph at the station located in downstream of reach. In order to evaluate the efficiency and accuracy of the models, the RMSE was used. The results showed that the hydrological method of Atkin is significantly less accurate than the graphic (regression) method of Convex, but it is more accurate compared to the two sub-methods of Singh and SCS of Convex. Also it was found that the graphical method of Convex (or regression) with an average error value of 21.26 m3/s. is more suitable than other methods in this research. And then the best methods include Atkin, Singh and SCS with RMSE values of 70.16, 77.87 and 79.3 m3/s. However, the difference between Singh and SCS methods is not serious. The RMSE values in all methods used in this research show a lower value in 50% Qp compared to the Qp. In Atkin's method, the amount of error in the conditions of using 50%Qp has reached from 78.5 to 70.71 m3/s. According to the mentioned results, it is recommended that researchers use 50%Qp in flood routing operation.