Madhumita Borthakur’s scientific contributions

Located in the floodplains of river Brahmaputra in Assam, Kaziranga National Park harbors the highest population of horned rhinoceros in the world, while Pobitora Wildlife Sanctuary holds the highest density of the species globally. The species which has bounced back from being endangered to being vulnerable relies on the alluvial grasslands which are replenished annually by flood waters. This study was conducted using the Radar imagery of Sentinel-1 and processed in SNAP software to identify water spread areas during the monsoon season of the year 2020. Within Kaziranga National Park, 50.7% of the area was found to be inundated on 22/07/2020, owing to the highest annual water level in the region as recorded by the hydrograph at Dhansirimukh (River Brahmaputra). On the same date, a maximum inundation of 81.5% of the area in and around Pobitara Wildlife Sanctuary too was found. The identification of inundated areas and predictive water spread areas help the protected area managers in wildlife management during floods.

This study was carried out in Hollongapar Gibbon Wildlife Sanctuary and 1 kilometer buffer area. It covers a total Geographical area of 47 square kilometer, out of which Wildlife Sanctuary covers an area of 20.98 square kilometer. An attempt was made to evaluate the changes that have taken place between 1989 to 2011. Remote Sensing and Geographical Information System was extensively used for analyze the land use/ Land cover change pattern. Satellite imageries of Landsat TM, USGS of 1989, IRS P6 LISS III of 2003 & IRS P6 LISS III of 2011 satellite imageries were used for analysing of Land Use-Land Cover change analysis. Different Image Processing techniques were applied by using ERDAS 9.1 software, such as Spectral & Radiometric Enhancement to improve the quality of the imagery to acquire more information for interpretation. Subseting of satellite images were done. Handheld GPS Garmin 60 was used to acquire the Geographical position and ground verification. In the present study visual interpretation was done by Arc GIS 9.3 software. Base map of different vector layers such as roads and wildlife sanctuary boundary were digitized from Survey of India Topographical sheet No. 83J/6. ASTER DEM 30 meter resolution data was used to analyze the elevation range of the study area. The study shows the decreasing trend of area under Evergreen forest from 1989 to 2011. In 1989, Evergreen forest represents 15.74 Sq. Km (33.48%), It has decrease to 13.24 Sq. Km (28.17%) in 2003 and followed by 11.57 Sq. Km (24.61%) in 2011. On the other hand, it has been observed that the area under tea garden has the increasing trend from 1989 to 2011. In 1989, the area under Tea garden covers an area of 15.65 Sq. Km (33.27%) and in 2011, it covers an area of 13.24 Sq. Km (28.17%). Key Words: Remote Sensing, GIS, Land use, Satellite Image.