Ecology and Thermal Stratification Dynamics of Freshwater Lakes in the Kashmir Himalaya

Kowser Jan

Abstract: Freshwater lakes of the Union Territory of Jammu and Kashmir (J&K) are ecologically and hydrologically important components of the western Himalayan landscape, supporting agriculture, fisheries, tourism and urban water supply across an altitudinal gradient of ~300 m to over 3,500 m. Despite decades of site-specific limnological study, there has been no coherent, comparative synthesis of stratification behaviour and trophic development for the region?s main lentic systems. This paper (i) synthesises published physico-chemical, thermal and remote-sensing evidence for twelve representative J&K lakes covering high-altitude, forest, rural valley and urban valley settings; (ii) characterises the region's distinctive stratification regime, where stable thermal stratification is largely limited to the deeper rural lake, Manasbal, which behaves as a warm monomictic system stratified for eight to nine months of the year, whereas the majority of shallow, wind-exposed valley lakes remain polymictic; and (iii) proposes a Lake Ecological Integrity Index (LEII), a composite framework integrating trophic-state, stratification-stability and catchment-pressure sub-indices, illustrated here using literature-derived classifications. This synthesis confirms a consistent oligotrophic to hypertrophic gradient from high altitude lakes such as Gangabal and Nundkol, through rural and semi-urban lakes such as Manasbal, Wular and Anchar, to urban lakes such as Dal, Nigeen and Khushalsar. This gradient is driven primarily by a change in catchment land-use, untreated sewage influx, and macrophyte-mediated nutrient cycling. This is compounded by documented long-term shrinkage in open-water area in both Dal and Wular lakes. The research also analyses accumulating evidence that warming in the Himalaya is expected to deepen and extend stratification in deeper lakes, while increasing hypolimnetic hypoxia risk, producing a compounding interplay between eutrophication and climate-driven thermal change. The LEII framework aims to provide geographically comparable, multi-lake monitoring and prioritisation for conservation investment throughout J&K, supplementing single-lake assessments with a regionally uniform, extendable tool for lake managers and policymakers.

Keywords: Lake stratification; Climate change; Composite index; Freshwater ecology

How to Cite?: Kowser Jan, "Ecology and Thermal Stratification Dynamics of Freshwater Lakes in the Kashmir Himalaya", Volume 15 Issue 8, August 2026, International Journal of Science and Research (IJSR), Pages: 2148-2153, https://www.ijsr.net/getabstract.php?paperid=SR26829143400, DOI: https://dx.doi.org/10.21275/SR26829143400

Download Citation: APA | MLA | BibTeX | EndNote | RefMan