Investigation of Surface Instability Processes in Burned Areas through Remote Sensing and Field Surveys

Wildfires strongly impact rocky, forested landscapes, driving erosion, debris production, and changes in sediment connectivity. This study combines field surveys, remote sensing, and experimental analyses in the 2021 Montiferru-Planargia Fire and 2022 Los Guajares Fire burnt areas to investigate these processes. Thermal spalling is identified as the key mechanism generating new debris and fractures, influenced by lithology, fuel load, and wind. Novel empirical indices—Fire Efficiency Index (FEI), Rock-Fuel Efficiency (RFE) and Fire-driven Erosion Rock Susceptibility Index (FERSI)—quantify these effects, linking vegetation energy and fire intensity and, consequently, photosynthesis activity and fire severity indexes, to geomorphic responses. Geological discoveries in Montiferru improve hazard assessment frameworks, while a standalone software derived by existing literature provides a scalable tool for rapid postfire erosion evaluation. Results highlight the interplay between wildfire, rock erosion, and sediment dynamics, offering predictive approaches for geohazard management and future research into fire-driven landscape evolution.