Empirical assessment of rockfall and debris flow risk along the Karakoram Highway, Pakistan

Abstract

The Karakoram Highway links north Pakistan with southwest China. It passes through unique geomorphological, geological and tectonic setting. This study focused 200-km-long section of the highway starting from Besham until Chilas. Landslides are frequent and are mostly triggered by torrential rain during Monsoon and Westerlies, leading to highway blockade. Rockfall and debris flow are prime mode of slope failures. Regional to site-specific approach was implemented to assess risk associated with these two modes. Remote sensing-based techniques were used to identify potential hazardous sites, which were further investigated for risk assessment. Modified Pierson’s rockfall hazard rating system (RHRS) rated potential rockfalls, whereas semi-quantitative technique was employed to assess debris flows. Normalized scores of each site shaped the final map, further classified into four zones: very high, high, intermediate and low risk.

Assessment of geological hazard susceptibility based on remote sensing images

“…Scholars commonly use the rockfall hazard rating system and the empirical model Flow-R to study rockfall hazards. Ali et al conducted a Runout assessment to identify potential high-probability rockfalls and debris flows [40]. Ji et al used the Rocfall v.4.0 software to perform a rockfall hazard analysis for slopes with potential rockfall hazards [49].…”

“…After completing experiments to assess flash flood outbreaks, Arnous et al concluded that an enhanced understanding of the mechanisms of interaction between topographic features and extreme meteorological conditions could lead to a better understanding of the causes of flood outbreaks [26]. Ali et al concluded that there are three primary conditions for the origin of a mudslide: slope, water source, and erodible unconsolidated sediments, which can be used as a vital source of evaluation factors for assessing mudslide hazards [40]. Hadji et al made relevant inferences about the effect of each parameter on the occurrence of SM from the corresponding coefficients appearing in the established logistic regression function, and they found several statistically significant causal factors among the selected slope instability factors [41].…”

Study on the Prevention and Control of Downhole Debris Flows Based on Disaster Chain Theory

“…A debris flow induced by the change in the original topography and geological conditions due to man-made mining is also called a "man-made debris flow" [7][8][9]. Essential differences exist between mine debris flows and natural surface landslides, tunnel debris flows, and other geological disasters [10,11]. Research related to the metal mine debris flow forecast theory and prevention and control methods is mainly concentrated in the field of open-pit debris flows, but a few reports on the prediction and control of downhole debris flows in downhole metal mines have been published [12][13][14][15].…”

Risk Assessment of Rockfall using GIS-Based Analytical Hierarchy Process: A Case Study of Bitlis Province

“…After that they performed a multiple regression analysis to determine the relationships between seismic factors and rock fall data. Ali et al (2021) focused on the Besham-Chilas region of Pakistan, where rockfalls and debris flow frequently triggered by heavy rains. They used remote sensing-based techniques to identify potential hazardous sites and rated potential rockfall by using modified Pierson's rockfall hazard rating system (RHRS).…”