INFLUENCE OF THE UPSTREAM RESERVOIRS ON THE ADJUSTMENT OF DOWNSTREAM ALLUVIAL CHANNEL
摘要
From the systematic analysis of field data of the existing reservoirs on the main stem of the Yellow River it has been found that different modes of operation of the reservoirs have different effects on the regulation of runoff and sediment load, and consequently, on the self-adjustment of the downstream channel. If a reservoir functions as water impoundment or flood detention, the sediment transport capacity will decrease because of the reduction of flood peaks. Espeially when large amount of sediment load are brought into the river by sediment-laden tributaries downstream of the reservoir, the deposition on the downstream channel will be getting serious, the conveyance capacity will decrease and the channel itself will degenerate. Under the operation of storing the clear flow and releasing the muddy the reservior capacity can be maintained for long-term use and the sediment transport capacity of the downstream channel can be increased. In the development of water resources by construction of reservoirs on a sediment-laden river, the influence of the alluvial channel self-adjustment induced by the changes in runoff and sediment load on flood control and environment must be considered.