سعید زارعی

The flood is an unusual water follow that endanger human life. Rivers have always been a major source of supply for mining materials. In recent years, the necessity of materials has become more important with the development of human construction activities. The riverbed is a vital place to harvest the fine and coarse materials. Therefore, lawful and unlawful sand and gravel harvesting is increasingly nowadays. Disruption of the riverbed structure causes changes in sediment transport rate and the riverbed strength and consequently a noticeable change in water level and flow velocity. Hence, the study of the effects of these perceptions on the flow structure during flood events are of special importance. In this research, it was observed that unauthorized and unauthorized harvesting of sand and gravel from the bed of Dalki River in Bushehr Province causes destruction of river bed forms, increased sediment transport and consequent flooding in surrounding areas, which requires more attention.