Оценка эрозионной опасности рельефа на основе цифрового моделирования

Abstract

On the basis of a digital elevation model (DEM) based on generalized data from USGS STRM DEM and ASTER GDEM with a resolution of 3″ with the help of GIS technologies, a morphometric analysis of the territory of the perm Territory at a scale of 1:2.5 million was carried out and a series of morphometric maps was created, as well as an assessment map of the erosion hazard of the relief. According to the results of morphometric analysis, the values of the index of vertical dissection of the relief in the region vary within the range of 0–623 m with an average value of 44 m. The steepness of slopes varies from 0 to 40° with average values of 3°. The horizontal dissection, determined on the basis of the thalweg network of permanent and temporary streams, varies in the range of 0.145–1.202 km/km2. Comparison of morphometric indicators in key areas with the data obtained by traditional methods of morphometric analysis revealed their coincidence at the level of gradations. The following geomorphological factions curtains: wide development of slope surfaces with elevation differences over 50 m and slopes exceeding 3°. According to the results of cartometric analysis, such conditions characterize 35 % of the region’s area. More than half of the region’s area (60 %) has an average density of erosional dissection of 0.5–0.8 km/km2, another 36 % of the area is characterized by moderate values of 0.2–0.5 km/km2. The calculated relief energy index has a value of 3–13 points; on its basis, 4 categories of relief erosion hazard were identified. In accordance with the results obtained, most of the perm Territory (63.0 %) is characterized by a low erosion hazardous relief, 36.6 % by a medium and highly erosion hazardous. The share of land, the relief of which is characterized by zero erosion potential, is 0.4 % of the region’s area.