Landslide Vulnerability Assessment Using Frequency Ratio Method: A Case Study of Irshalwadi Village, Raigad, Maharashtra

A very heavy 265 mm rainfall in a day on 19^th July 2023 at Irshalwadi, Maharashtra, had triggered a disastrous landslide at the geologically unstable village of the Western Ghats. The landslide had brought upon huge devastation, and loss of human lives in the region. Our research tries to figure out all the direct and indirect contributing factors and understand the correlations among them that led to this cataclysmic event. This research uses frequency ratio (FR) based technique for Landslide Susceptibility Mapping (LSM) of the Irshalwadi area. The proposed approach meticulously integrates diverse variables such as rainfall pattern in the area, slope of the land, aspect, curvature, distance to drainage, LULC, & geomorphology to define the landslide prone zones within the area and to precisely assess the landslide vulnerability of the area. By analyzing the results, we could clarify the efficacy in capturing the nuances of landslide dynamics by FR technique. Validation of the LSM model of Irshalwadi area was conducted using the Receiver Operating Characteristic (ROC) curve method. It produced a degree of validation accuracy which is significant enough in delineating landslide susceptibility for the given region. Our findings offer a pathway towards encouraging disaster preparedness and fostering resilience in similar landslide-prone areas of Western Ghats and India.