ASSESSMENT OF LAND SUSCEPTIBILITY TO HYDRIC EROSION IN SMALL RIVER BASINS FROM CENTRAL PART OF ROMANIA USING GIS APPLICATIONS - Carpathian Journal of Earth And Environmental Sciences

Hydric erosion is a geomorphologic process which produces significant damages in agriculture through loss of fertile soil horizons in the southern part of Transylvanian Depression. Integration of the Geographic Informational System (GIS) and RUSLE model was used for achieving research on hydric erosion susceptibility and quantifying erosion rate in Secaşul Mare river basin. The erosion factors are addressed in detail, each factor being than described, assessed and accurately illustrated by applying specific equations and modern analytical tools for evaluation and analysis of them. The article is also investigating the relationship between climate, soil type, slope character, land cover and land use and the erosion rate in two small basins from south-western part of Transylvanian Depression. The results suggest many strong relationships between annual erosion rate (t/ha/year) and geological substrata, length slope and soil character. The greatest differentiations in spatial distribution of erosion rate are given by the land cover management factor. The values obtained for annual erosion rate vary between 0 – 94 t/ha/year. The values of equation factors indicate that this region, by its nature, is vulnerable to erosion. The human impact through inappropriate land use and pressure on lands lead to accelerating the erosion processes. Local scale variability of parental material and soils, morphology and morphometry of landforms, pluvial erosivity and land use are strongly related to the concept of altitudinal zonality and indicate the distribution of high values of annual erosion rate, frequently, in the plateau and submontainous hills. This procedure of integrating GIS with RUSLE model offers the possibility to develop and expand researches on soil erosion in different geographical regions and is an excellent tool for use in regional and local scale studies because of the possibility to obtain a rapid evaluation and visualization of the average erosion rate and land susceptibility to erosion and to compare the results.