On the environmental impact of alluvial placers exploitation on channel processes in rivers

Abstract

The alluvial palcers exploitation by dredging interferes with natural course of channel processes, especially in valleys of IV to VI orders. lt has been established by calculation that repeated dredging of a placer over considerable length of a valley may result in decrease of liquid discharge by 40 to 50%, and affects sediment budget as well. The changes could have serious repercussions in the lower links of the drainage network.