Fractional Vegetation Cover Analysis for Understanding Vegetation Cover Dynamics in Northeast India

要旨

Vegetation structure and composition may change dramatically over time in a variety of landscapes. Fractional vegetation cover ( sv) is an important factor defining the changes in vegetation cover in temporal domain and the land atmosphere interactions. From regional 200 m monthly composite WiFS normalized difference vegetation index (NDVI) data from year 1998 and 2000 sv is derived based on annual maximum NDVI value (NDVImax) of each pixel. The changes in sv value have been analyzed to assess the vegetation cover dynamics in 1998 and 2000. The paper presents the approach for the ?v estimation from IRS WiFS dataset for the northeast region. The results revealed that there is decrease in the sv. Out of the samples of 135 analysed for the changes in sv, 92% of the areas showed decrease in fractional vegetation cover. The changes are attributed to human defined land use practices and climate changes. The increase in some of the areas is due to abandoned shifting cultivation. Such a dataset is important in modeling of the land atmosphere exchanges of momentum, energy, water and trace gases. The methodology could be applied for the entire country to understand the Land atmosphere interaction.