TN-98 : Classification of lakes and inventory of natural lakes in India

Abstract

The earth land is dotted with about three million lakes, most of them being located in Northern Hemisphere. Many times lakes, ponds and reservoirs are wrongly considered as simile but there are certain basic differences between the three. According to Zumberge and Ayers ( vide Chow, 1964 ) a lake is defined as an inland basin filled or partially filled by a water body whose surface dimensions are capable of producing a barren wave swept shore.

Lake hydrology is a relatively new science and not much research on lake hydrology has been carried out in the world. In India research studies have been undertaken mostly on chemical and biological aspects of lakes. A few studies have been done on water quality and sedimentation also but other aspects of lake hydrology remain almost untouched. The increasing popularity of lake due to its various usage leads to deterioration of lake water both in terms of quality and quantity. To solve the hydrologic problems effectively a classification system based on hydrological approach is needed. But no such system exists hitherto. Most of the classification systems in existence consider only the biological, thermal and chemical behaviour of lakes_ There are other few studies of lakes related to specific problem. Classification given by Hutchinson in 1957 is based on the origin of lakes and is adopted by most scientists. The various ways of classifying lakes include classification based on region, origin, thermal behaviour, biological and chemical characteristics and morphology of lakes. These classifications, though adequate for other related areas of lake studies, are not adequate to meet the requirements of hydrological studies. So a classification system needs to be developed wherein lakes can be classified into various classes depending upon the hydrological parameters such as interaction of lake water with ground water, residence time of lake etc. These parameters can be clubbed with the other hydrological and hydro meteorological parameters which control the hydrology of lakes and hydrology and ecology of the surrounding catchment. Such a classification system will facilitate better and proper management of lakes.

The technical note deals with the various categories of existing lake classification with salient features of each class supplemented by a few examples in each category. A list of important lakes in India is also included at the end.