Land Degradation and Management within Upper Racova Catchment

摘要

Land degradation has been recognized as an important environmental threat in the Moldavian Plateau of eastern Romania. This study was designed to estimate the magnitude of land degradation and to review land management in a small catchment in the Central Moldavian Plateau. Several methods were deployed to estimate soil erosion losses, gully distribution, landslide inventory and reservoir sedimentation rates. Results obtained in the study area of 7,766 ha, of which 31% is arable and 32% native forest, show that the mean value of soil losses by water erosion on agricultural land is 19.0 t hasup?1/supysup?1/sup. By adding the woodland contribution, this value significantly decreases to 12.8 t hasup?1/supysup?1/sup. Then, a large proportion of land (58%) is covered by landslides. Most of them are shallow and dormant (stable), and the active ones form only ~2% of the total landslide area. Siltation rates determined using sup137/supCs reflect the impact of land management on deposition patterns in reservoirs. Proper conservation measures were applied over a 20-year time-span from 1970-1990. Since 1991 the contour farming system collapsed and returned to the traditional ‘up-and-down slope’ farming system on very small plots.