Uttarakhand tragedy due tosand mining, says expert
Among the several causes for the Himalayan tragedy in Uttarakhand, one is the indiscriminate exploitation of river resources, mainly sand mining all along the rivers. This is more pronounced in the Mandakini, a river flowing near the famous Kedarnath temple, that was the worst-hit.
Construction of hydro-electric projects impounding the water upstream, construction of several buildings and habitations, a reluctant State government not following eco-sensitive zoning regulations prescribed by the Centre and unscientific mining of sand have contributed to Nature unleashing its fury, says M. Anji Reddy, Professor of Environmental Science & Technology, at the Jawaharlal Nehru Technological University here.
In an interview to The Hindu , he explains how the seemingly simple act of removing sand from the banks of a river can lead to the destruction wrought by flood waters in Uttarakhand. The sand layer at the sides of what are called ‘flood plains’ (banks) and river terrace are the first obstructions to gushing water and the first and most effective shock absorbers. The sandy layer softens the blow and the fury of the gushing water is decimated, making it to flow further at much-reduced speeds. The geological cross-section of a river bed, he says, is a few metres of sand followed by thick layers of mud, boulders, hard rocks and sand again, after which there are aquifers -- bodies of porous rock -- through which water moves easily and from which groundwater is extracted. If there is a three-metre deep layer of sand on the flood plains, sand can be mined only up to one metre, say guidelines based on scientific calculations.