Landslide Hazard Zonation Mapping Near Galel, Along The Mumbai-Goa Highway

Abstract

The proposed study is dedicated to the formulation of the landslide hazard zonation map of the Galel section of Mumbai 2 Goa Highway (NH-66), which is a zone of landslides that is often triggered by monsoon flows. The methodology combines geotechnical studies such as Standard Penetration Tests, grain size distribution analysis, Atterberg limits as well as specific gravity analysis with geospatial approaches based on Sentinel-2 images along with SRTM-generated Digital Elevation Models. A GIS was employed to carry out Analytical Hierarchy Process (AHP) to weight several variables including slope, lithology, soil properties and land cover to generate a multi-criteria hazard map. The zonation categorised into five levels of hazards in the area which include; very low, low, intermediate, high and very high. Comparisons with past landslide inventories showed a very close match between areas of high risk calculated and the observed failures. Its findings can be used to guide slope stabilization/drainage projecting and mitigation priority actions along the NH-66 to ensure a substantial reduction in the hazard in a replicable model in case of other landslide-prone corridors of the Western Ghats.