oa Reconstruction of the geomorphosystem of the upper reaches of the Chorna Tysa river basin due to the action of natural and natural-anthropogenic factors

The Department of Earth Science and Geomorphology of the Faculty of Geography of the Taras Shevchenko National University of Kyiv from the 90’s of the 20th-century has been conducting systematic field and semi-stationary studies of the natural system of the upper part of the Chorna Tysa River basin (Halahan et al, 2019). In the winter and spring of 1999, due to the natural and natural-anthropogenic factors, there was a natural disaster at the local level. It affected the natural complex of the territory including morphosystem as its most stable element.

Studies of morphosystems of the upper part of the Chorna Tysa River basin allowed us to draw a number of conclusions. Basin morphosystems continue to persist within their spatial boundaries. They continue to build their structure which combines modern and ancient morphological elements. Basin geomorphosystems show the “ability” to withstand external influences. The stage of quiet evolutionary development (bifurcations) was replaced by the stage of stabilization of one stable position of the channel. Transportation and accumulation on the slopes at the bottom often depended on random causes (eg, the presence of fallen trees, man-made structures). They also depended on the genetic types of slopes and their attachment to vegetation (forest or grass). If the genetic types of slopes did not change much in the hypsometrical higher areas (often covered with shrubs, grass, moss), then in the case of thalweg there are many such cases, especially in the lower part of the basin. In particular, in the starboard side near the exit to the valley of the Chorna Tysa River, a case of replacement of the defluxion slope (covered with forest) with a bare landslide was recorded. The basin geomorphosystems of the Apshinets River, in contrast to other basin formations, has practically recovered in a few years and, thanks to new morphological qualities, will be able to withstand future natural disasters.