Forest Cover in India
The forest cover includes all lands which have a tree canopy density of 10 percent and above and have a minimum area of one hectare. The forest cover reported in the ISFR does not make any distinction between the origins of forest stand (whether natural or man-made) or tree species and encompasses all types of lands irrespective of their ownership, land use and legal status. Thus, all tree species along with bamboos, fruit bearing trees, coconut, palm, etc. and all areas including forest, private, community or institutional lands meeting the above defined criteria have been termed as forest cover.
The satellite based remote sensing data of LISS-III has been used in the forest cover assessment. The mapping has been carried out at a scale of 1:50,000 with Minimum Mapping Unit (MMU) of one ha. The digital image analysis of satellite data for forest cover mapping takes into consideration the reflectance behaviour of different tree covers. The reflectance from the trees is dependent on the crown foliage and chlorophyll content present in the leaves that is exposed to the incident radiation of the sun. In technical terms, it is the leaf area index (LAI) that determines the extent of the leaf area exposed to the radiation and accordingly being reflected back to the sensor.
There are other factors as well that influence the reflectance behaviour of the various features on the ground. The use of LISS-III sensor data of 23.5m x 23.5m pixel size, choice of 1:50,000 map scale and one hectare area as Minimum Mapping Unit (MMU) is based on various considerations such as large area of the country to be mapped, short periodicity of two years between successive cycles, country level perspective of reporting and data availability. The MMU of one hectare may be described as the cartographic limit of the stated map scale corresponding to a discernible polygon of 2 mm by 2 mm in size on the map.
Source: Forest Survey of India, Dehradun. State of Forest Report (2013)