Water quality assessment of natural lakes and its importance: An overview

Abstract

The proportion of freshwater on earth’s surface is only 2.5% of which only 1% is accessible for use. In this context, lakes are one of the most important water resources and have been used as a source of water supply for human consumption and in general accounts for about 0.3% of the total surface water body sources. As such, the conditions of lakes have been in constant deterioration due to increased anthropogenic activities surrounding them. In principle, the quality of lake water (or other surface sources) is evaluated using various physico-chemical and biological parameters selected on the Designated Best Use (DBU) of the water body (lake) for various purposes. Consequently, the use of Water Quality Index (WQI) is an important tool used for designating the quality of lake water. In general, natural lakes are confined bodies of water lacking a strong flow for self-cleansing of its water and therefore leading to accumulation of various impurities. In such cases, the quality of these impurities are determined using different indices like Heavy Metal Index (for heavy metals), eutrophication potential (due to nutrients) and other associated indices system. The determination of existing properties helps in determination of future trends of such pollutants and thereby the quality of the lake water in future scenario. Different modelling techniques are used for prediction of futuristic changes in lake water quality including watershed models, ground water models and lake models. The present study gives an overview and critically evaluates the literature on all aspects of water quality to give an insight of the various tools and techniques used for complete water quality monitoring and management.