Anthropogenic Stressors Transforming the Hydrogeomorphology of the Loktak Wetlandscape Hosting the Keibul Lamjao Floating National Park, NE India

ABSTRACT

Landscape enriched with wetlands, alias wetlandscape, in alluvial valleys provides important ecosystem services such as storage and dispersal, with implications for regional geomorphology and ecology. Despite consistent efforts to conserve and manage these ecosystems, they are continuously lost and degraded around the world because of anthropogenic interventions and climate change. Further, strategies for the management of wetlands typically focus on individual wetlands, giving little attention to the controls operating at other scales. In this study, we propose a protocol for a multiscale analysis starting from the catchment to the wetlandscape to the wetlands. We present a case study of the Loktak wetlandscape in the Imphal valley in NE India, hosting two globally important wetlands, the Loktak and the Keibul Lamjao National Park. We performed a geomorphic and hydrodynamic analysis and identified the controls and drivers of wetlandscape transformations based on historical satellite datasets, hydrometeorological variables and field observations. We document that the number of wetlands in the wetlandscape decreased from 19 to 11 between 1969 and 2023, whereas the area of the Loktak, Ikop and Pumlen wetland complexes declined by 3%, 43% and 41%, respectively, during this period. This degradation is primarily attributed to a major human intervention in the Manipur River, the Ithai barrage built in 1983, which led to significant inundation (29% more than the prebarrage condition) in the Loktak wetlandscape. The Ithai barrage caused a major shift in the hydrological regime of the Loktak wetland complex, which further propagated to other wetland complexes and associated channels. Temporal analysis of LULC of wetlandscape documents a remarkable transformation of wetlands to aquaculture, resulting in a change in hydroperiod pattern. Our study recommends several long‐term strategies for the restoration of the Loktak wetlandscape based on a process‐based understanding and incorporating the livelihood needs of the inhabitants of Loktak.