Investigating the effects of erosion control efforts on improving soil properties in areas damaged by dam and road building

Lately, serious ecological and socio-economical changes have been taking place in the Watershed of the Coruh River due to Coruh Dam Projects implemented by the General Directorate of State Hydraulic Affairs. Some negative effects of land degradation on natural resources of the Watershed have being observed during the construction of one of these projects, the Deriner Dam and building of new roads. However, there is not much scientific research on the degree of land degradation and success of precautions taken against it.In this study, erosion control and tree planting efforts to stop soil erosion and to improve soil properties in damaged areas as a result of building new roads, a part of the construction of the Deriner Dam, were investigated. In accordance with this purpose, soil samples were taken from three different areas; two of which are erosion control areas with terraces built and acacia and yellow pine seedlings planted and the one is an undisturbed (control) area with natural forests. In order to represent the whole study area, total of 60 disturbed soil samples were taken both from terraces and from sloping area left between terraces built for erosion control purposes in damaged areas. In addition, for comparison, 15 soil samples were taken from the undamaged natural forest area that has not affected by the road construction.Collected soil samples were analyzed for a total of six soil parameters including soil texture, pH, organic matter, total nitrogen, total lime, and electrical conductivity. By running variance analyses on these soil parameters, we tried to determine whether there are any improvements (rehabilitation) in soil properties of damaged areas with the help of ongoing erosion control and planting efforts. After evaluating statistical analyses run on the soils data, there were significant differences found for soil properties at terraces and between terraces in erosion control and reforestation areas. Moreover, it was determined that the reforestation efforts have resulted in improvements of soil properties at some degree but when they are compared to the soils of the undisturbed natural forest, it is clear that the degree of improvement is not sufficient yet. However, it can be stated that the areas planted with acacia seedlings have better soil properties than the areas planted with yellow pine seedlings.Key Words: Land degradation, soil erosion, erosion control and reforestation efforts, improvement of soil properties.