A Simplified Mathematical Equation to Study the Relationship between Water Driving Forces and Water Losses Amount in Irrigation Canals in the Field

Abstract

This investigation aimed to study the effect of water driving forces in irrigation canals in the case of using one or two irrigation canals in the field and its impact on water losses amount by deriving a mathematical equation. The results across the two seasons showed that mean water driving forces (WDF) in the case of using one irrigation canal in field (0.26m3/16.63minute) was greater than two irrigation canals (0.24m3/36.13minute) and the water losses amount (WLA)resulted from using one irrigation canal (17.78 m3) was less than the two irrigation canals (36.25 m3) by saving 18.47m3 of irrigation water. Consequently, there is an inverse relationship between water driving forces in irrigation canals in the field and water losses amount. Grain yield in the case of using one irrigation canal in the field was 1.414 mg ha-1, while in the two irrigation canals recorded 1.365 mg ha-1by increasing 49.17 kg ha-1. Accordingly, a quantity of irrigation water can be saved during surface irrigation in order to achieve water abundance can be used to irrigate new lands. The quadratic model was the best statistical model to describe the relationship between Water Driving Force (WDF) and Water Movement Time (WMT) irrigation canal in field. Using the fitted quadratic model, it is clear that the Critical Water Movement Time (CWMT) which reflects the lowest WDF value was 25.55 min.