04 May RIVER GEOCHEMISTRY
River Geochemistry deals with the study of the chemistry of the dissolved constituents of water. This study is very relevant now as the humanity is more dependent on such limited resources like the surface water and underground water these days than any time in the past. The knowledge of dissolved salts in water is a pre-requisite for making any decision on the proposed or potential use of water for any specific industrial, irrigational or domestic purposes.
Secondly, another important reason to have knowledge of the content and concentration of dissolved salts in water, arises out of the utility of such data on studies relating to the rates of denudation of the rocks and sediments exposed on the surface of the earth. Such data are used in conjunction with the suspended load concentration, in the computation of denudation/erosion rates of river basins. The bed load of any stream is bound to the slowest moving load down-river and it constitutes only a minor fraction of the total load.
Studies on the spatial and temporal variations of the load flux through the river channels are considered highly useful by geologists, geochemists, geomorphologists and environmental scientists. The appreciation of water chemistry and soil chemistry are essential in tracing the pathways of elements through the plant and animal kingdoms. In fact, elements that are present in the tissues of plants and animals can easily and up in human tissues, when such vegetables and meat are consumed.
The suspended/dissolved loads of rivers are highly variable with season and from place to place in the river. Many of the toxic elements may ‘ride piggy back’ on suspended particles, and thus may be deposited in the channel or flood plain, to be resuspended in the stream flow at a later date.
It is proposed that studies on the geochemistry of river water, of the soils etc. should be undertaken to map the distribution and concentration of elements that are useful or harmful to man as well as animals and plants. It should be followed up by preparation of an atlas with plates displaying the distribution of such elements, for consultation by the planners and engineers concerned with the welfare and public health.