The Dimensions Effect of Border Irrigation Basins on Irrigation Efficiency, Distribution and Uniformity Coefficient

Abstract

The surface irrigation model with mathematical expression in stream flow was applied in a border irrigation system for an agricultural area in Al-Mussaib city north of the Babylon governorate in central of Iraq in which divided into basins of different dimensions. This study aims to select the optimum area for basins (dimensions) and their relationship into soil type to show the ability of fully submerged basins in standard time with high irrigation efficiency and uniform distribution along the border. The improvement of field irrigation efficiency was done by studying the relationship between soil type, flow rate, slope, and basin area. Geographic Information System (GIS) and Remote Sensing were used to analyze satellite imagery, identify the topography and inclinations of the area, as well as the possibility of classifying the soil by collecting field data for the study area and measuring the discharge on-site with calculation of irrigation efficiency, distribution efficiency, uniformity, progression and infiltration time. After analyzing the results and graphically, it was concluded for the case of providing a large basin of silty soil with high discharge, the infiltration time is long with increase in losses, the value of irrigation efficiency was 63%. For small basins with dimensions (20 * 120) m and flow rate, 0.04 m 3 / s, the irrigation efficiency was approximately 77% due to the convergence and parallelization of the infiltration time with advance time of irrigation, which requires making the land basin small. According to the results, when the soil type is clay, the results showed that basin can be small or large with making leveling of the land in a slope of not more than 3%, but when the soil is silty, the basin designed in small dimensions to obtain highest uniformity and minimum time required.