Author(s)

H. M. Al-Ghobari

Abstract

In this study an evaluation of the areal distribution of applied water above and below the soil surface for six center pivot systems was conducted under field conditions, to quantify the subsurface distribution of soil water content and water application on the ground surface. The measured application depth of water and water distribution patterns with the distance from the pivot were presented. Field experimental results showed evidence of the importance of redistribution of the applied surface water. The values of the subsurface uniformity coefficients were higher by approximately 12% than the surface values. It was found that the water within the soil is more uniformly distributed than that applied above the soil surface. An experimental relationship between the uniformity coefficients above and below the soil surface was derived under center pivot sprinkler irrigation systems. Keywords: water distribution, water uniformity coefficients, center pivot, sprinkle irrigation, nonweighted coefficient of uniformity, water application, areal distribution. 1 Introduction With population growth in the world, the demand of water is increasing. Hence, the necessity for conservation of water resources increases, particularly in countries of limited water supply, where the agricultural irrigation has traditionally been the major water use sector in these areas, usually in the range of 80 to 90%. The sprinkler irrigation system is widely and universally spread. This is because it has flexibility and water application can be controlled

Keywords

water distribution, water uniformity coefficients, center pivot, sprinkle irrigation, nonweighted coefficient of uniformity, water application, areal distribution.