Snow Avalanche Susceptibility Mapping using Remote Sensing and GIS in Nubra-Shyok Basin, Himalaya, India

Abstract

Objectives: To produce an avalanche susceptibility map using static terrain factor accountable for avalanche occurrence in Nubra-Shyok basin, Himalaya, India. Methods/Statistical Analysis: Expert judgements based Analytical hierarchy process model was applied in the present study. The weight values for each avalanche contributory factor (aspect, elevation, slope, curvature and ground cover), was assigned by comparing possible pairs in a matrix. Receiver operator characteristics-Area under the Curve technique was used to validate the results. Findings: The calculated weight values of the slope factor is 0.47, which is found most significant, while the weight value of elevation factor is 0.25, were also found to be significant factor. The weight value of Ground cover was 0.05 and creates a least importance. The curvature and aspect weight values were 0.12 and 0.11 respectively, and produce intermediate degree of importance. The avalanche susceptibility map of the Nubra-Shyok basin was divided into five zones:-(I) Very High (II) Moderate-to-High (III) Moderate (IV) Low (V) Very Low, and covers 27.5% , 28.0% 19.0%, 20.0%, and 4.8%, of the total area respectively. ROC-AUC method was applied to verify the study results. The value of Area under the curve (0.9112) shows that results of the present study are acceptable and 91.12% avalanche pixels are properly categorized. Application/Improvements: This study will help in safe movement across the Nubra-Shyok basin, India.