Evaluating the land use land cover dynamics of Loktak Lake, A Ramsar Wetland of International Importance in North East India

Abstract

In fragile transitional freshwater ecosystems, such as a wetland, the increasing anthropogenic and natural pressures, including climate change, and industrialisation, have impacted the land use/land cover (LULC). The present study aims to identify the LULC changes occurring in Loktak Lake, a Ramsar Wetland of International Importance, included in the Montreux Record between 2009 and 2020 using LANDSAT imageries. It also attempts to undertake landscape modelling to look at the fragmentation of phumdi class through FRAGSTATS utilising the Number of Patches (NP), Patch Density (PD), Largest Patch Index (LPI) and Cohesion metrics. In order to quantify the LULC, a Maximum Likelihood Classifier was carried out in Arc GIS 10.8.1. A total of 6 classes were classified viz open water body, athaphum, phumdi, built up, agriculture and barren area. An overall decline in phumdi, athaphum, agriculture and open water body at the rate of 5.92 %, 14.31 %, 110% and 0.92% was observed. Meanwhile, built-up and barren showed an overall increase at the rate of 18.31 %.and 31.25 %. These LULC changes observed have been primarily because of anthropogenic factors, which threaten an already fragile ecosystem. The landscape modelling exercise showed that phumdi is aggregated at the innermost portions of the lake. It also showed that the patches of phumdi were higher in 2011 and 2020, which may be due to the use of phumdi strips in athaphum (fish farms on the lake). The study indirectly revealed the effectiveness of past management actions by relevant organisations, as remotely sensed information requires ground validation. It also highlighted the absence of baseline data information and emphasised integrating present, past and future LULC modelling for management purposes.