ESTIMATING ANNUAL SOIL LOSS BY WATER EROSION IN THE MIDDLE PRUT PLAIN, REPUBLIC OF MOLDOVA

Estimating annual soil loss by water erosion in the middle Prut Plain, Republic of Moldova. Modern technology has provided efficient tools such as advanced models and Geographic Information Systems to facilitate decision making for environmental management. Studies at this subject are available in literature, ranging from those that use a simple model such as USLE to others of a more sophisticated nature. In this study the model selected (modified Universal Soil Loss Equation – USLE) and the case itself is kept simple due to significant limitations in data on land processes. An effective investigation of soil loss by using GIS – USLE integration requires spatially distributed data on several parameters describing the terrain surface. Such parameters include topography, rainfall characteristics, soil types, vegetation, land use, and the similar. In Republic of Moldova data on most of these parameters are collected often on a local or individual basis, and therefore, a well-organized regional or basin-wide database is not available. In the Republic of Moldova soil erosion is often as high as 30 tons/ha/year and more than 1.4*106 ha run a potential risk of erosion (Summer & Diernhof, 2003). The model estimated an annual quantity of soil eroded ranging over the Prut River tributaries watersheds between the mean values of 6.2 and 20.4 t/ha/yr. Much of the areas are within the range 10-20 t/ha/yr. The highest values of the quantity of eroded soil is carried out on strong inclined slopes corresponding to areas with agricultural lands and herbaceous vegetation. The results have shown that GIS can be effectively used to investigate critical regions within a basin with respect to erosion.