Document Type: Research Paper
Department of Range and Watershed Management, Ilam University, Ilam, Iran
Department of Water and Soil Sciences, Ilam University, Ilam, Iran
Wind erosion is considered as one of the main processes of land degradation in different parts of the world. Among the most effective ways to control wind erosion is to cover land surface with natural vegetation area. In this study, 3 replica soil samples were collected, at a depth of 0-3 cm, from various land uses in Dehloran, Ilam Province, Iran. Physical and chemical characteristics of soil samples were determined in the laboratory to allow the application of the ENVI_met Headquarter model commonly used to design biological windbreak. The threshold friction velocity (TFV) is the basic parameter for effective construction of a windbreak. To determine its values, a wind tunnel test was conducted. Based on simulation results with the pattern designed with Prosopis juliflora species, it was observed that the wind speed decreased in front of the windbreak but returned to the initial speed at a larger distance behind the windbreak. Therefore, the designed windbreak for this species is able to reduce the wind speed to a far distance while in the designed windbreak with Haloxylon aphyllumspecies the wind returns to the initial speed within a shorter distance. According to the results, the wind speed reduction is directly related to the height of windbreak. Moreover, the designed windbreak with P. juliflora species, more effectively reduce the wind speed and protect longer distances behind the windbreak; thus it can be proposed as a suitable windbreak for the study area.