The specification of the temporal change and erosion trends of varied land uses on Kackar granitoid in Trabzon-Galyan Atasu Dam rain basin

In this study the specification of the temporal change and erosion trends of varied land use on Kackar granitoid in Trabzon-Galyan Atasu Dam Rain Basin have been invesitagted. It should be indicated that the identification of the effects of varied land uses on different characteristics of basin soils, particularly the specification of the effects on erosion trends, will contribute much to the management of rain basin. For this aim, 137 samples representing the basin have been taken from varied land uses in the rain basin (meadow, agriculture and forest). Sample areas have been selected from the same bedrock (Kackar granitoid) in the each land use. By opening land profiles,I took the soil samples in the agricultural areas according to the depth levels and in the meadows and in the forested lands according to the horizons. In the laboratory researches, various physical (texture, dispersion rate, clay dispersion rate, dust dispersion rate, structural stability index, colloid- humid equivalent rate, field capacity, erosion rate, wilting point, available water capacity, bulk density, particle density, pore volume) and chemical (organic substance, EC and Ph) characteristics have been determined. Important differences among the land characteristics according to the method of land use have been detected. Erosion trend indexes (dispersion rate, erosion rate, colloid-humid equivalent rate) were above the limit values in the research basin lands. This result shows that the lands in the dam basin are sensitive. The dispersion rates in all forms of land uses are greater than 15%. Besides, it has been identified that the dispersion rate was at its lowest level in the agricultural area and at its highest level in the leafy forest area. Because of the fact that the method of land use and bedrock have significant effects on various characteristics of basin soils, these characteristics should be taken into consideration in the scientific studies. Keywords: The method of land use, Erosion trend indexes, Permeability, Soil characteristics