Impact of the Hoa Binh dam (Vietnam) on water and sediment budgets in the Red River basin and delta
Impact of the Hoa Binh dam (Vietnam) on water and sediment budgets in the Red River basin and delta
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DOI：
10.5194/hess-18-3987-2014
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发表时间：
2014-10
影响因子：
6.3
通讯作者：
V. D. Vinh;S. Ouillon;Tran Duc Thanh;L. Chu
中科院分区：
文献类型：
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作者：
V. D. Vinh;S. Ouillon;Tran Duc Thanh;L. Chu
华平大坝位于越南红河的一条支流上，库容为9.45×109m 3，于1988年12月投入使用。虽然华平大坝对越南北部的防洪、发电和灌溉非常重要，但它也对红河下游流域、三角洲和沿海地区的悬浮泥沙分布产生了很大影响。通过50年来的流量和悬沙浓度数据集(1960-2010)分析了其影响，并利用MIKE11数值模型模拟了大坝下沉前后三角洲9个口的水沙分布。虽然三角洲入海口的流量只减少了9%，但河内附近的Son Tay的年悬浮泥沙通量平均下降了61%(从119万吨/年−1降至46亿吨/年)。在沿海，沉积速率的降低与自华平大坝蓄水以来观察到的较低的泥沙输送是一致的。水量调节导致雨季排水量减少(松泰红河的−为14%)，而枯季的排水量增加(同一站点的排水量增加了12%)。北部和南部河口的水沙比在9个河口的总流量中有所增加，而中部和主要的巴拉口则有所下降。海防港疏浚泥沙数量的增加是金巴当北部河口淤积的证据。讨论了潮汐抽水对枯水期水流增强的影响，认为这是河口蓄水后泥沙淤积加剧的可能原因。
The Hoa Binh dam (HBD), located on a tributary of the Red River in Vietnam, has a capacity of 9.45 × 10 9 m 3 and was commissioned in December 1988. Although it is important for flood prevention, electricity production and irrigation in northern Vietnam, the Hoa Binh dam has also highly influenced the suspended sediment distribution in the lower Red River basin, in the delta and in the coastal zone. Its impact was analysed from a 50-year data set of water discharge and suspended sediment concentration (1960–2010), and the distribution of water and sediment across the nine mouths of the delta was simulated using the MIKE11 numerical model before and after the dam settlement. Although water discharge at the delta inlet decreased by only 9%, the yearly suspended sediment flux dropped, on average, by 61% at Son Tay near Hanoi (from 119 to 46 × 10 6 t yr −1 ). Along the coast, reduced sedimentation rates are coincident with the lower sediment delivery observed since the impoundment of the Hoa Binh dam. Water regulation has led to decreased water discharge in the wet season (−14% in the Red River at Son Tay) and increased water discharge in the dry season (+12% at the same station). The ratios of water and suspended sediment flows, as compared to the total flows in the nine mouths, increased in the northern and southern estuaries and decreased in the central, main Ba Lat mouth. The increasing volume of dredged sediments in the Haiphong harbour is evidence of the silting up of the northern estuary of Cam–Bach Dang. The effect of tidal pumping on enhanced flow occurring in the dry season and resulting from changed water regulation is discussed as a possible cause of the enhanced siltation of the estuary after Hoa Binh dam impoundment.