GEOMORPHOLOGIC POSITIONS OF DEBRIS FLOW BASINS IN THE LOVOZERSKIYE TUNDRY MOUNTAINOUS AREA

The Lovozerskiye Tundry mountainous area belongs to the northern zone of debris flow formation.The territory is characterized by an average degree of debris flow hazard.We defined 35 debris flow basins in the Lovozerskiye Tundry using the remote-sensing data and field survey.Depending on their geomorphologic position, the debris flow basins were divided into the following groups: 1) catchment areas of temporary streams on the outer slopes of the massif; 2) catchment areas that include erosional (tectonic-erosional) valleys of permanent streams and adjacent slopes of interfluves; 3) catchment areas taking over the complexes of glacial landforms (kars, cirques and troughs) and adjacent slopes of interfluves.Basins of the third type were divided into two subtypes: catchment areas taking over the complexes of glacial landforms with a significant degree of fluvial reworking and adjacent slopes of interfluves (first subtype) and catchment areas taking over the complexes of glacial landforms with a slight degree of fluvial reworking and adjacent slopes of interfluves.Almost half of the debris flow basins in the Lovozerskiye Tundry massif belong to the second type of catchment areas, and about 40% to the third type of catchment areas with a slight degree of fluvial reworking of glacial landforms (second subtype).We selected the most representative basin in each type (subtype) for a detailed de scription of its geomorphologic structure and debris flow morphodynamic zones.A comparative analysis of the inner structure of basins belonging to different types allowed finding a relation between the morphodynamic zones of debris flow basins and their geomorphologic positions.The basins of the first and second types are characterized by larger accumulation of debris-flow material within the cones.The same situation is typical for basins of the third type with a significant degree of fluvial reworking.The largest accumulative bodies in the third type basins with the slight degree of fluvial reworking are concentrated within the inner part of the valleys. © 2022 Moskovskij Universitet. All rights reserved.