Satellite-based long-term spatiotemporal trends of wildfire in the Himalayan vegetation

Abstract

Analysis of the spatiotemporal pattern of burned areas over time is necessary to understand how fire behavior in the Himalayan region has altered as a result of the complex climatic variables. The differenced Normalized Burnt Ratio (NBR) is calculated utilizing the cloud-based platform Google Earth Engine (GEE) to quantify the extent of burned regions. The spatial distribution of burnt areas in the Himalayan region over the last 21 years has been examined and correlated with climatic and edaphic factors in the current study. The area affected by forest fire has shown a direct correlation with the land surface temperature, but an inverse relationship with surface soil moisture, pre-fire precipitation, pre-fire Normalized Difference Vegetation Index (NDVI) and pre-fire Enhanced Vegetation Index (EVI). The p-value for 9 of the 20 regions in which the research area has been divided for the spatial analysis is less than 0.05, implying that the regression model is statistically significant. Trend analysis done using Mann–Kendall test and Theil–Sen estimator state the distinct trends of burnt area and other meteorological and edaphic parameters in the Western, Central and Eastern Himalaya. The assessment of burned areas aids forest managers in mitigating the impacts and managing the forest fires, as well as in the implementation of the restoration methods following a forest fire.