Soil erosion in river basins of Georgia

Resumo

The area of cultivated lands in western and eastern Georgia comprises 28–40 and 29–33% of the total catchment areas, respectively. Eroded arable soils in Georgia occupy 205700 ha, i.e. 30.5% of the total plowland area, including 110500 ha (16.4%) of slightly eroded soils, 74400 ha (11%) of moderately eroded soils, and 20800 ha (3.1%) of strongly eroded soils. The maximum denudation rate in catchments of western Georgia reaches 1.0 mm/yr. The minimum denudation (0.01 mm/yr.) is typical of river catchments in southern Georgia. The mean annual soil loss from plowed fields in western Georgia reaches 17.4 t/ha and exceeds the soil loss tolerance by nearly four times. In eastern Georgia, it is equal to 10.46 t/ha and exceeds the soil loss tolerance by 2.5 times. In southern Georgia, the mean annual soil loss from plowed fields is as low as 3.08 t per ha, i.e., much lower than the soil loss tolerance.