Forest Fire Susceptibility Mapping of West Sikkim District, India using MCDA techniques of AHP & TOPSIS model

Abstract Forest fire poses major environmental hazard, to the extent of sometimes permanently damaging the forest ecology. The potential of human to repair nature is hampered by the extension of human domination into forests, which results in the loss of forest land. While human expansion cannot be stopped, we must accept responsibility for the consequences and thus work to minimize such environmental hazards emanating from such calamities. RS and GIS have proved to be useful techniques for such studies. The goal of the current study is to identify the most vulnerable forest fire zones in the West Sikkim district falling within the state of Sikkim (India) during 2004–2021. Various thematic layers (LULC and topographical factors) were created using Landsat 8 OLI and ASTER DEM. For the final forest fire susceptibility zone (FFSZ) map, climate variables such as precipitation, temperature, humidity, and wind speed were also used. The authors employed the MCDM techniques of AHP and TOPSIS to determine the areas which are most vulnerable to wildfires in the research area. 194 wildfire locations, as obtained from Sikkim State Disaster Management Authority (SDMA) were used for the classification. The FFSZ were classified as “very high, high, medium, low, and very low vulnerability zones” based on their fire vulnerability. The areas under “Very high Susceptibility Zone” of AHP and TOPSIS were 152.331 km2 and 348.499 km2 respectively whereas the areas under “Very Low Susceptibility Zone” were 115.351 km2 and 139.436 km2 in the results of AHP and TOPSIS respectively. To check the accuracy of the FFSZ susceptibility maps obtained from the two modeling techniques, the same were confirmed by using (Receiver Operating Characteristics) ROC curves. Result indicates that the TOPSIS model (AUC = 82.28%) is slightly better at determining the vulnerable zones than the AHP method (AUC = 72.25%). Use of Geo-spatial technology can be an effective tool for delineating forest fire-prone areas of West Sikkim district. A fire risk map is useful for preventing possible tragedies by allowing and planning of enough fire-fighting infrastructures in areas vulnerable to fire damage.