VARIATIONS OF WATER QUALITY INDICATORS IN CLOSED TROPICAL FRESHWATER SYSTEMS TOWARDS SELECTED CLIMATIC AND ANTHROPOGENIC DISTURBANCESA. Verma, Adhidesh S. Kumawat, A. Purohit, S. Meghwal, D. Karki and A. Kandara
Inland waters are nowadays becoming hotspots of endangerment. Disturbance is any change in set ofenvironmental conditions which alter regular ecosystem properties that may be natural or anthropogenic.Disproportionate enrichment due to several point and non-point sources has affected water quality and natural trophic status of inland waters where climate change can be an indirect factor. Lakes are significant indicators of climate change and store house of information about changes in catchment characteristics. Climate change may affect tropical lakes more comparatively. Water temperature affects a number of lake properties that influence the wellbeing of lake ecosystem. Increasing temperature and deviation of normalrainfall pattern have been evidently studied for changes in chemical composition of lakes. The presentstudy is an effort to investigate the effects of change which can be direct or indirect occurring over a periodof time in a closed system (Purohitokatalab) of Udaipur, Southern Rajasthan with reference to alteration inits water quality subjected to several tourist activities within recent years. Such isolated lakes lack selfcleansing mechanism due to absence of strong flow. The values and alterations of parameters i.e. pH, TDS,conductivity, turbidity, total hardness, chlorides, sulphates, nitrates, phosphates, DO, BOD indicate thequality of lake water. Several samples of water from the periphery of this closed lake system were collectedduring year 2017 and 2021 and these water quality parameters were analysed. Results indicated high variation in the N:P ratio within the freshwater body. It also demonstrated increasing trends in nitrateconcentrations, alkalinity and biological oxygen demand over the time period with change in temperature and rainfall variations. Major changes in the catchments characteristics and measures for its management were also discussed to avoid further deterioration of the closed natural ecosystem. Here future monitoring of water quality indicators is crucial to assess the impact of climate change on such tropical closed systemsas it is a potential threat stimulating the precursors of eutrophication and overall alteration of ecologicalstate of lakes.