DefinePK

Abstract

Extraction or mining of sand and gravel from river beds/flood plains plays an important role as aggregate in construction industries but has placed immense pressure on the environment, where sand and gravel resources occur. Present study was carried out to determine the environmental effects of sand and gravel mining in Malir River bed in Karachi. Field work was carried out in the study area to determine the physical environmental effects of mining. Results show that destruction of landscape, reduction of farm, grazing land and lowering of water table are the environmental effects that result due to sand and gravel mining in Malir River. Due to continuous open pit mining of the sand and gravel deposits of more than 100 ft thickness, the underlying bed rock which is a part of Gaj Formation of Miocene age is exposed on the surface of river bed, which may destroy the existing aquifer system in near future. Sand mining is widespread and highly unregulated in the Malir area. It is concluded that the government develops and implements policies designed to protect the environment around Malir sand and gravel mining areas in Karachi.