Assessment of NDVI and NDWI over burhisuti wetland of Assam using IRS LISS III Data

Natural wetlands are considered as a source of natural resources. Wetland monitoring using remote sensing methods is always found to be accurate and scientific by researchers. The Burhisuti wetland is situated in the easternmost part of Assam to the north bank of Brahmaputra River. This is an inland wetland of natural origin that covers a geographical area of 24.29 sq. km. This study attempts to make an assessment of the status of NDVI and NDWI parameters of Burhisuti wetland of Assam using IRS LISS III satellite imageries of 2008 and 2013 for postmonsoon season. The NDVI and NDWI techniques are most effectively used remote sensing indices derived from multispectral satellite imagery for assessing surface water and vegetation status over the earth's surface in general and over wetland surface in particular. The mean NDVI value generated from LISS III imagery of 2008 for the study area is found to be 0.329 that changed to 0.432 during 2013. Similarly, the mean NDWI value generated from LISS III imagery of 2008 for the study area is found to be-0.035 that changed to-0.297 during 2013. The study has also assessed three intensity zones (low, moderate and high) over the study area based on NDVI and NDWI value range. The high intensity NDVI zone in the study area mainly represents the area with dense vegetation, while the high intensity NDWI zone represents the area with clear surface water. It has been also observed from the study that among the three intensity zones, the moderate intensity zones with mix pixels of water and vegetation share maximum proportions to the study area for both indices during 2008 to 2013.