A Comparative Appraisal on Satellite Remote Sensing Data as a Utilitarian Tool in Forest Health and Fragmentation Analysis

The health of the forest vegetation is one of the driving factors and indicator of climate change impacts. Fragmentation of the forests on the other hand brings out the implications of the various stressing factors on the spatial extent of the forests especially the increasing population and industrialization, which has always impacted the forested regions in the form of deforestation for commercial purposes and conversion of forest land for cultivation. Hence there is a demand for spatial assessment and continuous monitoring of the forested regions. With a wide range of advancing technologies, remote sensing methods are increasingly being employed for monitoring a number of remotely measurable properties of different types of vegetation.This paper reviews the utilitarian application of remote sensing as a tool to assess the health of the forest regions. The various multispectral satellite image derived vegetation indices like Broadband and narrowband Greenness, leaf pigments, canopy water content and Light use efficiency can be used as a combined tool to generate a comprehensive health metrics for the forest canopy. These new indices may be useful in remote sensing plant physiology status as well. Various band ratio exist for above factors depending on the bands available in the selected dataset. A detailed discussion of the existing multispectral satellite sensors capable of studying the forest canopy is presented herewith, in addition to briefing on the potential of the latest microwave remote sensing technique for vegetation studies. The estimated vegetation indices can be used to generate the final health map of forest regions. Any change in the spatial extent of the forested areas and their pathway for future change can be assessed by the fragmentation analysis.The application of the discussed techniques in various environmental conditions are elaborated and the constraints in addition to the requirements for effective forest health monitoring is provided in this review.