What was the main cause for the rapid spread of fire in BRT reserve? Using remote sensing and geographic information system (GIS) tools, the Forest Department, in association with a Pune-based earth observation company, mapped the forest area in Punjur range – Chikkayanagiri valley near Kurimande camp – that was damaged by the fire.
Forest department officials vouch that these methods are scientifically accurate, transparent and ensure complete coverage of the area. The accuracy of the maps can be verified on ground or by anyone as satellite imagery is freely accessible.
Imagery from the Landsat 7 satellite was acquired for the dates of February 13 and 28. Images were processed and analysed, and their Normalized Burn Ratio (NBR) was calculated.
The analysis resulted in a map of the affected range showing burn severity in categories. These maps were then tested for accuracy using handheld GPS devices. Results showed a total of 574 acres of forest area affected by fire, said Chief Conservator of Forests, Chamarajanagar territorial division, B.P. Ravi.
After mapping the highest severity fire locations, another analysis was conducted to study the reason behind such rapid spread of the fire. In 2016, the Forest Department and Terra Analytics had made a 3D VR map of the entire BRT Reserve using UAVs for the purpose of mapping the extent and density of lantana infestation.
The lantana maps were visualised along with the current fire polygons in GIS software and calculations showed that 90% of fire affected area is forest where lantana occupies more than 70% ground area, Mr. Ravi said in a release here.
Satellite images from 2005 to 2015 also show that most fires have occurred in areas with dense lantana cover. For a more in-depth analysis, the 3D map of these burnt areas was used.
Lantana is an invasive weed that degrades the surrounding forest by capturing most of the available resources. The Forest Department is currently experimenting with the removal of lantana and converting it to briquette or a block of compressed coal dust or peat used as fuel, in a programme aimed at restoring forest health and providing employment to the local Soliga community.
“The fire has been completely extinguished and restoration measures are on. The department has mapped the ‘hotspots’ of severe fires for stepping up ground-based vigils to prevent any further fires this summer,” he said.
