Landslide susceptibility assessment in the Rangun Khola watershed of far western Nepal

Abstract

Considering the serious threat of landslides to life, property, and the environment, this study aimed at exploring past landslides (2005-2020) to evaluate landslide susceptibility. The study is carried out in the Rangun Khola watershed, in western Nepal covering an area of 488 km2. The landslide inventory map was prepared, recognizing 494 landslides, among them 70% were used for susceptibility mapping, and the rest 30% for validation purposes. The size of the landslide was found in the range of 103.53 m2 to 149120.1 m2, with an average of 4677.35 m2. Frequency ratio (FR) and logistic regression (LR) models were implemented for landslide susceptibility assessment based on the various intrinsic factors. The validity of the models was assessed by using receiver operating characteristic (ROC) curves. The success rate was 87.6% for the LR model with a prediction rate of 87.3% indicating a good degree of fit. Similarly, with a success rate of 76.4% and a prediction rate of 75.1%, the result obtained from the FR model was a fairly good performance. Thus, both exhibited reasonably good accuracy in predicting the susceptibility of the landslide and are considered to be in land management and hazard mitigation, and policy formulating purposes.

Estimation of soil erosion using the Revised Universal Soil Loss Equation (RUSLE) in Relation to Landslides in Mid-hills of Nepal

“…in Relation to Landslides in Mid-hills of Nepal decades, leading to erosion (Pathak & Devkota, 2022a). In this watershed, the natural elements, particularly the weather elements, are highly erosive (Dhital, 2015).…”

“…In this watershed, the natural elements, particularly the weather elements, are highly erosive (Dhital, 2015). Because of the high intensity of monsoon rainfall over short periods of time, the erosivity of rain and run-off are major drivers of soil loosening, slope weakening, and finally mass movements of solid and semi-solid materials such as soil creep, landslips, and landslides (Bhandari et al, 2021;Koirala et al, 2019;Pathak & Devkota, 2022b). Like many of the hilly areas that are on the way of being developed, this watershed is also in the growing phase of development.…”

“…With the ongoing developmental activities and some other development projects in the pipeline for future developments, the risk of soil erosion and landslide events (Bhandari et al, 2021;Pathak & Devkota, 2022a). As a result, the Rangun Khola watershed can be assumed to be under constant pressure for various agricultural and urban developments.…”

Estimation of soil erosion using the Revised Universal Soil Loss Equation (RUSLE) in Relation to Landslides in Western Mid-hills of Nepal

“…In this watershed, the natural elements, particularly the weather elements, are highly erosive (Dhital 2015). Because of the high intensity of monsoon rainfall over short periods of time, the erosivity of rain and run-off are major drivers of soil loosening, slope weakening, and nally mass movements of solid and semi-solid materials such as soil creep, landslips, and landslides (Koirala et al 2019;Bhandari et al 2021;Pathak and Devkota 2022b). Like many of the hilly areas that are on the way of being developed, this watershed is also in the growing phase of development.…”

Development and Application of a Real-Time GIS Digital Platform for Landslide Risk Analysis

“…Recovery of mental well-being tends to occur relatively swiftly once the situation is addressed, in contrast to the prolonged recovery periods associated with physical health issues or loss of life. Consequently, the presence of a digital platform capable of offering supplementary information equips government agencies to enhance their problem-solving efficiency [13][14][15]. Currently, the monitoring and surveillance of landslides in Thailand rely on data provided by the Department of Mineral Resources.…”