TN-104 : Sedimentation in lakes

Abstract

Sedimentation is one of the major problems the lakes all over the world are facing. The deposition of the sediments begin to destroy the lake the moment they appear. From the available information, although little, it can be concluded that the life of many Indian lakes is already severely affected by sedimentation.

This review note discusses in details the physical process of sedimentation in lakes besides describing the various factors, major and minor, controlling the process. River and wind are the major natural agents that carry sediments to the lake. Their. deposition and movement is affected by various other factors either directly or indirectly through their effect on the circulation of the lake water. Morphology of the lake, climate of the region being the principle factors. The report also discusses the various existing methods for the estimation of sedimentation. Sampling is the most commonly used methods. Remote sensing and isotope techniques are the more advanced methods but have their limitations either practical or economical. An economic and efficient method for the estimation of bed load is yet to be developed.

Sedimentation has a profound impact on the quality of the lake water through the bio-chemical activities enhanced by the sediments. This has been discussed at length.

Looking at the poor status of the research on the sedimentation studies of lakes in India an urgent need is felt to attend to this problem for the preservation of these natural resources which would otherwise undergo an untimely destruction.