Determination of the ecologically effective channel depth for the purpose of extraction of nonmetallic building materials in lowland rivers

Abstract

Extraction of non-metallic building materials from channels of lowland rivers is an important factor of technogenic impact on river channel processes, which has already led to significant changes in riverbeds of several rivers in Russia, flowing close to large cities. In order to minimise the negative impact of riverbed quarries (also referred to as river sediment extraction sites) on the environment, it is necessary to determine the ecologically effective parameters of deposit exploitation from river channels. This paper proposes criteria for the permissible (effective) depth of riverbed quarries. The objective of the permissible depth is to ensure the minimum water surface slope in the longitudinal profile and the flow velocity not lower than the velocity limit for deep erosion to occur. The calculation methods for permissible depth has been tested for the Oka River.