ИСТИНА

The highland cirques mostly created by nivation and glacial exaration occupy large areas in mountains and they have a significant role in the sediment redistribution of the river basins. The share of sediments in the overall sediment flow related with partly ice circus surface depends on rock lithology, terrain morphology, set of the exogenous and endogenous processes and its spatial combinations, vegetation (if its exist), and also from the morphological and functional connection of waters and sediments between the cirque and the other parts of basin. Even in the condition of very active erosion and planation of the cirques surface, barely a lot share of the sediments may be transported to the river valley because its mainly redeposited in the local depressions and channel extensions. The approximately assessment on the connection of the sediment flow between glacier cirques and river valley in gives the sediment connectivity index analysis. We study the spatial distribution of the connectivity index for a typical glacier cirque – the Koiyavgan cirque near the join of the Main Caucasus Range and its offshoot (the Gumachy range). This area is situated in the upstream part of the Adil-Su valley (a left-side tributary of the Baksan river ). In August 2020, we made a high-resolution orthophoto image (13+ cm) and construct a digital elevation model (27+ cm) based on aerial photography with DJI Mavic Pro. The territory located in the elevation range from 3230 to 4022 m.