Landslide Mapping and Assessment along the M41 Highway in the Pamir Mountains, Southeast Tajikistan

Abstract

Landslides are a significant natural hazard in Tajikistan destroying settlements, damaging infrastructure, and causing loss of human lives in mountainous regions and valleys of Tajikistan. There has been little work on landslide assessment in Tajikistan and most landslide studies to date have focused on specific areas, events, or types, and in many cases only published in the local language. In these studies, none has specifically focused on landslide risk along the M41 highway in the Pamir mountains. This research intends to assess landslide inventory, susceptibility, hazard, and risk, especially along the M41 highway in the Pamir mountains, southeast Tajikistan with the high-resolution imagery using ArcGIS and RStudio.
From SPOT image interpretation and field investigation, 1,300 landslides were identified, classified and mapped, and three main landslide types were identified: slide, debris flow, and long-runout debris flow (the total length more than 1,800 m). Landslide susceptibility was generated using these three landside types and six causative factors (slope gradient, aspect, elevation, stream power index, land cover, and lithology) produced results with a fair to good performance (77 - 84 % of success rate). The annual probability of occurrence of three landslide types was prepared from the frequency-magnitude analysis, and runout modelling using a Gravitational Process Path model. High hazard zones are more likely to be found on the western rather than the eastern of the area due to topographic conditions. The risk assessment on the M41 was evaluated using hazard probability, vulnerability assessment and element at risk. The total damage costs to the M41 road section in the area are approximately $3.2M - $12.8M for debris flow, $2.8M - $4.4M for long-runout debris flow, and $16.36 for slide. Medium and very high- risk catchments are mainly located in the west and south of the M41 road in middle of the study area.

Date of Award	26 Sept 2023
Original language	English
Awarding Institution	University of Portsmouth
Supervisor	Malcolm Whitworth (Supervisor) & Nick Koor (Supervisor)