Remote Sensing and GIS in Spatial Monitoring of the Wetlands: A Case Study of Loktak Lake Catchment, India

Abstract

Occurrence of the wetlands is characterized where the land is covered by water or the water table level is close to the land surface. Wetlands are the only ecosystems for whose conservation an international convention called Ramsar Convention was set up in the year 1971. According to Ramsar Convention, a wetland is “areas of fen, marsh, swamp, peat either artificial or natural with water which is flowing or static including areas of marine water the depth of which should not exceed six meters.” As per Ramsar Convention in 2019, there are 2341 Ramsar sites listed across the world, among which Loktak Lake is one of the Ramsar sites nestled in the North-Eastern Himalayan ranges. Distinctive feature of this lake is the presence of herbaceous floating biomass (herbaceous wetlands) locally known as phumdis. In this case study land use land cover (LULC) of Loktak Lake catchment was mapped with special emphasis on wetlands and herbaceous wetlands. Based on the driving factors and past LULC for the year 2007, 2014 and 2017, the future LULC for the year 2030 was predicted by Land Change Modeller (LCM) in TerrSet using Landsat 5 and Landsat 8 multispectral satellite imageries. Artificial neural network (ANN) and Markov chain algorithms embedded in the LCM were deployed to predict the future LULC condition. ANN was trained with driving factors, namely slope and elevation, distance from built-up area and distance from roads. Results indicate that there was decrease of 28.65% and 6.08% in herbaceous wetlands and wetlands, respectively, in the year 2017 as compared to the year 2007. Similar trends were observed in the future projected LULC map of 2030 with a decrement of 6.48% and 41.56% in wetlands and herbaceous wetlands as compare to the baseline scenario of 2007. Based on the result of projected scenario, it is evident that there is a need to devise proper environment conservation policies.