Detecting Land-Cover Change using Mappable Vegetation Related Indices: A Case Study from the Sinharaja Man and Biosphere Reserve

Abstract

Understanding the effects of human disturbances at the forest fringe is useful in efforts to implement best management practices aimed at conserving forest resources. This study evaluates multi-year changes of vegetation in the Sinharaja Man and the Biosphere (MAB) reserve using mappable vegetation related indices viz., Normalized Difference Vegetation Index (NDVI) and Burn Index (BI). Land-cover changes in the Sinharaja MAB reserve were detected using Landsat 7 ETM+ images for 1993, 2001, and 2005, and DIVA GIS land-cover data in 2000. NDVI resulted in a 962 ha increase of vegetation prime at the western Sinharaja from 2001-2005 and a 15 ha decrease of vegetation at the southern Sinharaja from 1993-2005. Results from BI showed that the Sinharaja MAB reserve fringe is vulnerable to forest fire. This vulnerability can be seen in the following totals of burned hectares: 160 ha from 1993-2001, 79 ha from 2001-2005, and 10 ha for the entire period of 1993-2005. According to the land-cover map, burn area occurred at the cultivated lands, scrublands, and fragmented forest fringe. The results were visualized using an embedded 3D render window of Google Earth and a 2D view of ArcGIS explorer online. In conclusion, in-situ ground truthing data is needed for the fire-influenced area for implementing sustainable forest resource management at the Sinharaja MAB reserve.