Quantitative assessment of mudflow risk in the Greater Caucasus of Azerbaijan (on the example of the northeastern slope)

Abstract

The recreational and tourist direction of Azerbaijan’s development planned the development of hard-to-reach mountainous areas, where construction of various engineering structures will be carried out. Mudflows are the most destructive geological processes, since mountain geosystems are characterized by favourable conditions for their occurrence – high seismicity (8–9 points), increased moisture (700 mm or more), intense weathering of rocks and accumulation of loose clastic material, etc. Thus, the territory of the northeastern slope of the Greater Caucasus is classified as a mudflow hazardous area. This takes into account the areas of mudflow basins, the intensity of the passage of diverse mudflows, their quantitative characteristics, the conditions of formation, as well as the amount of damage caused to both the infrastructure and the residential complex. The purpose of article. The article considers the results of field ecogeomorphological studies on the northeastern slope of the Greater Caucasus, dedicated to the quantitative assessment of mudflow risk for the period from 1990 to 2020. The research methods. Large-scale topographic maps (Scale 1:100000) were used to assess the degree of mudflow risk on the northeastern slope of the Greater Caucasus in order to obtain morphometric characteristics (including about the incline of the slopes, the length and shape of the slopes, the areas of mudflow cen- ters), as well as materials of interpretation of different-scale and different-time ASI. On the example of the basins of the mudflow-prone rivers Gusarchay and Velvelichaу, ASI M 1: 60000 1996-2020 from the Landsat satellite were used to determine the quantitative indi- cators of the areas of mudflow centers. The results of research: Based on the interpretation of the ASP within the northeastern slope of the Greater Caucasus, according to the degree of danger of mudflow processes (the amount of removed material, the erosive effect of the flow on the valley, taking into account the occurrence of mudflows in tributaries and the basin as a whole, as well as the prevailing types and classes of mudflows, geomorphological conditions of formation, forming and the passage of mudflows and the statistical data on past mudflows), and on the actual and possible damage to the population from mudflows, a mudflow risk map was compiled on a 5-point scale. Conclusions. The reasons for the acceleration of the frequency of passage of destructive mudflows made up of dirt, stones and mud on the northeastern slope of the Greater Caucasus are related to the degradation of high-mountain meadow and moun- tain forest landscapes of the Gudyalchay–Velvelichay, Davachichay–Atachay and other interfluves. Based on the decoding of the ASI from 1996–2020 from the Landsat satellite (M 1:60000) mudflow sources in the basins of the most mudflow-bearing rivers Gusarchay and Velvelichay for the period 1990–2020 were calculated. The research results will make it possible to use the obtained data for the development of a program for the safe and sustainable functioning and development of the hard-to-reach mountainous geosystems of Azerbaijan for recreation and tourism development.