Forest Fire Susceptibility Mapping of West Sikkim District, India using MCDA techniques

Abstract

Forest fire poses a 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 the “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 modelling techniques, the same was confirmed by using (Receiver Operating Characteristics) ROC curves. The result indicates that the TOPSIS model (AUC = 82.28%) is slightly better at determining the vulnerable zones than the AHP method (AUC = 72.25%).