The use of empirical equations for seepage estimation in comparison with observed losses from irrigation canals

• Published in: Journal of water and land development no. No 57; pp. 21 - 29
• Main Authors: Syed, Naeem S.B., Shuqi, Zhao
• Format: Journal Article
• Language: English
• Published: Polish Academy of Sciences 19-05-2023
• Subjects: empirical equations; equation modifications; seepage estimation; seepage losses; seepage rate
• ISSN: 2083-4535; 2083-4535
• DOI: 10.24425/jwld.2023.145332

This study analyses and presents a technical comparison of seepage estimation from 11 empirical equations with measured seepage losses by the inflow-outflow method from two lined and unlined secondary irrigation canals sub-divided into different reach lengths. A significant margin of error was observed between empirical and inflow- outflow methods, hence modifications in empirical equations were performed. Results reveal that the average seepage losses observed in unlined and lined canals by inflow-outflow method were 9.15 and 3.89%, respectively. Moreover, only the Chinese equation estimated seepage losses for an unlined canal as similar to observed losses (0.11 m 3∙s –1) whereas the Indian equation estimated similar results for a lined canal to those observed in the field (0.09 m 3∙s –1). However, the rest of empirical equations were modified in accordance with error percentage with regard to the observed losses. The empirical equations were then observed to estimate reliable results of seepage.