| چکیده انگلیسی مقاله |
Investigating the pattern of moisture distribution and proper estimation of wetting front dimensions in different soils in drip irrigation are important in order to provide solutions to improve water use efficiency in the field, especially in arid and semi-arid areas. In order to achieve the proper water use efficiency in micro-irrigation systems, the space and flow of the Emitters should be match with the hydraulic characteristics of the soil and the time and amount of irrigation water for plant. As a result, having proper information about the width and soaked soil depth is essential for the design and management of the drip irrigation systems. The shape of wetted soil volume is one of the important parameters in selecting the emitters and it influences the irrigation scheduling, and the emitters spacing. The purpose of this study was to achieve a set of semi-experimental relations for more accurate and easier estimation of the diameter and depth of wetting front. The field data of trickle irrigation systems were gathered by Wetting Front Detector (WFD) installed in three different conditions in terms of soil texture and flow rates of 4 and 8 l.hr-1. Due to technical difficulties and errors in the measurement of saturated hydraulic conductivity that is the main representative of soil characteristics, the presented relations here, estimate the dimensions of the wetted soil volume based on the time of penetration and the volume of water stored in the reservoir, without need to the soil hydraulic conductivity. The obtained equations in this study predicts the diameter and depth of wetted soil volume with correlation coefficient of 89 and 98%, respectively. Using these relations to estimate the dimensions of the wetted soil volume, it is possible to design and plan the drip irrigation system more correctly. |
