Exploring the Hydro-Ecological State of Himalayan Lakes: A Review
Abstract
Lakes are complex hydro-ecological bodies that support a myriad of ecosystem services around the world. The Himalayan region is a treasurable source of freshwater in the entire Indian subcontinent dotted by a number of freshwater lakes providing various services like water supply, flood and drought mitigation, irrigation source for agriculture, replenishing groundwater, recreation, aesthetics, tourism, fisheries and biodiversity. Himalayan lakes are indispensable resources for local livelihoods and ecological sustainability of the region. However, climate-driven changes and anthropogenic activities such as population increase, land use/land cover changes, agricultural intensification, intensive construction, fresh water abstraction, tourist influx, etc., are causing severe alterations to the fragile limnetic ecosystems. Impact of these changes on the lakes is observed on its physical variables (heat balance, thermal structure, mixing, stratification, etc.) as well as its aquatic ecosystem (water quality, phytoplankton, oxygen, nutrients, etc.). Mountainous lakes are usually smaller in size and thus more sensitive to both natural and human-induced disruptions in their watersheds. The freshwater lake systems in the Himalayas being exposed to such alterations resulted in persistent depletion of water levels and deterioration of water quality. Despite the Himalayas posing the challenges of accessibility, altitude and weather, various studies have been performed. Review of literature on Himalayan lakes at different altitudes suggests that most high-altitude lakes are oligotrophic or ultraoligotrophic and most lesser Himalayan lakes are in eutrophic and hyper eutrophic category. Recent decades saw glacier melts along with evolution and expansion of glacial lakes leading to future threats of glacial floods. However, most studies conducted are on physico-chemical characteristics and very few on bathymetry, hydrological budgeting, rate of sedimentation, paleolimnology and holistic limnology. An efficient management of lakes requires a robust understanding of the dynamics of underlying lake processes, water budgeting and regular water quality monitoring. Further, long-term field-based limnology research are needed to be conducted in the Himalayan region.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.H55S0958S