As much as 1,077.7 sq km or 44.15% of Goa’s forest cover is “very highly susceptible”, 491.58 sq km (21.35%) “highly susceptible”, and 543 sq km (15.62%) moderately susceptible to fires, an ICAR-Central Coastal Agricultural Research Institute vulnerability mapping study has found. The study published in the Journal of Environmental Management in March concluded that open and moderately dense forests were highly susceptible to forest fires, with the distance from human settlement being the other crucial factor.
Scientists A R Uthappa, A Raizada, and Bappa Das studied data on past fires to analyse criteria such as forest density, distances from human settlement, nearest road, elevation, slope, direction of the land, surface temperature, topographic wetness index, and average normalised difference vegetation index. They drew a susceptibility map using machine learning models.
The study said roads through forests made fires more likely, primarily on account of cigarette buds and roadside cooking by travellers. The absence of pre- or post-monsoon rains influenced factors like the topographic wetness index, land surface temperature, and the Normalised Difference Vegetation Index, a measure of the amount and health of green vegetation, also led to an increased susceptibility to forest fires.
Das said Goa and the surrounding region received scanty rain between November 2022 and March 2023, coinciding with high forest fires. “This is because when dry trees tend to shed their leaves, the land surface temperature rises and the wetness index falls, making the forests more susceptible to fires,” Das said.
He added that they found the forest type was the most important factor in forest fire susceptibility. “Forest areas at a distance of 1100 metres (1.1 km) from human settlement showed high susceptibility with the map indicating that the risk of fire was low close to human settlements, increased the further one went away from the settlement, peaked at 1100 metres and decreased thereafter.”
{{/usCountry}}He added that they found the forest type was the most important factor in forest fire susceptibility. “Forest areas at a distance of 1100 metres (1.1 km) from human settlement showed high susceptibility with the map indicating that the risk of fire was low close to human settlements, increased the further one went away from the settlement, peaked at 1100 metres and decreased thereafter.”
{{/usCountry}}The study found that south and west-facing lands that receive higher sunlight are more susceptible to fires. Forests at higher elevations are less susceptible. Lands with greater inclination are less vulnerable.
The study underlined that the forest cover in Goa and the adjoining states of Karnataka and Maharashtra plays a key role in maintaining the hydrological balance of the Western Ghats, which is the source of fresh water.
The Western Ghats, spread across India’s western coast from Gujarat to Kerala, are a chain of low mountains. Tropical evergreen forests (75%) on the western side of the chain receive more rainfall. The eastern side comprises moist deciduous forests (13%). The rest of the Western Ghats is interspersed with grasslands, rocky plateaus, and open forests.