Demands and Potentials of Shipping Development under Joint Regulation of Three Gorges and Upstream Cascade Reservoirs on Yangtze River
The rise of upstream water level induced by large reservoir impoundment and the increase of downstream minimum discharge directly raise the navigation water level,laying a foundation for the improvement of channel scale.However,upstream sediment retention and clear water discharge cause siltation at reservoir tail,downstream riverbed erosion,and channel stability deterioration,unfavorable for waterway stability.Given the existing water resource allocation and large-scale waterway regulation efforts,the shipping targets outlined in the "14th Five-Year Plan" can be basically achieved.Nevertheless,the downstream water level decline caused by clear water discharge and riverbed erosion will significantly increase the dredging volume of the waterway after 2025,according to the current minimum discharge flow.It is estimated that from 2025 to 2030,the Three Gorges Reservoir needs to increase the minimum discharge to a range between 6150 and 6500 m3/s to ensure the stability of the downstream sandy gravel channel water level.Properly increasing discharge flow from upstream reservoirs can significantly ease the difficulty of channel scale improvement in Yibin-Chongqing section.In addition,optimizing reservoir operations and extending the duration of specific flow levels can reduce the difficulty of daily waterway maintenance.
Yangtze River shippingcascade reservoirsjoint regulationwaterway scalewater resources allocation
万方数据
维普
