عنوان مقاله [English]
نویسنده [English]چکیده [English]
Different kinds of irrigation canal lining materials have different durability based on climatic conditions. Therefore it is necessary that in different areas, all various lining approaches be evaluated and suitable lining be selected to decrease seepage loss, and optimum usage from water resources. The aim of this research was to study the effect of concrete lining to reduce water seepage loss in the main irrigation earth canals that serves the irrigated area on Hamadan province. Total length of concrete-lined irrigation canals in this province is 500 km. 12 main lined and unlined canals with total length of 13.5 km were chosen to study in this area. Water seepage in these canals was measured by the inflow-outflow method. Water flow velocity was determined using a current-meter. The water seepage loss at unlined-canals was between 1.32 and 3.06 m3m-2day-1. The average seepage loss was 2.39 m3m-2day-1 equal to 16.4% in 1Km. The water seepage loss at concrete lined-canals was between 0.55 and 2.40 m3m-2day-1. The average seepage loss was 1.74 m3m-2day-1 equal to 8.2% in 1Km. Based on statistical analysis, there was no significant difference for seepage loss between lined and unlined canal types. It was noted that the average seepage loss of the chosen concrete lined-canals was much higher than the standard value of water seepage loss for open concrete lined-canals.