Analysis of a simplified approach for the determination of modified Kostiakov model parameters

Abstract

Accurate estimation of infiltration losses is very important in many hydrologic projects. However, the lack of available data often forces hydrologists to resort to the application of empirical and semi-empirical models for estimating the infiltration rates. Estimation of infiltration rate from these empirical and semi-empirical models is highly dependent on the method adopted to determine the parameters of models. One of the most common infiltration models known as the Kostiakov model was modified to rectify zero infiltration at the start of the infiltration process. Recently, a simplified approach for determining the parameters of the modified Kostiakov model was proposed. The present article focuses on analyzing the reliability of the simplified approach for determining the parameters of the modified Kostiakov model. In this regard, six observed datasets were analyzed from different parts of the world to arrive at some generalized results on the reliability of the simplified approach. Cumulative infiltration obtained from simplified approaches was compared with that obtained through the application of an excel spreadsheet-based nonlinear optimization solver. It was found that on average Sum of Square of Error reduced by 72% on application of nonlinear optimization as compared to the simplified approach. HIGHLIGHTS Recently, a simplified approach was proposed to determine the modified Kostiakov infiltration model.; Comparison of simplified approach to nonlinear optimization.; Nonlinear optimization was found more accurate.;

Keywords

• infiltration
• modified kostiakov model
• nonlinear optimization
• parameter