IMPACTS OF THE VUNG TAU - GO CONG SEA DYKE ON HYDRODYNAMIC FLOW REGIME
IMPACTS OF THE VUNG TAU - GO CONG SEA DYKE ON HYDRODYNAMIC FLOW REGIME
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头顿 - 古康海堤对水动力流态的影响
DOI：
10.15625/1859-3097/17/3/10592
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Bui Duc Toan
中科院分区：
文献类型：
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作者：
Nguyen Hong Lan;Bui Duc Toan
西贡-东乃河下游地势低洼，受洪涝、咸水入侵等自然灾害影响较大，给社会经济发展带来困难。为了解决这些问题，提出了建设32公里长的Vung Tau-Go Cong海堤的项目，特别是建造蓄水和防止咸水入侵的水库，扩大城市空间，工业园区，旅游，服务，避风港，储备未来的淡水。然而，由于围头丛海堤的修建，将改变该地区的水动力状况，导致河口淤积，改变盐沼生态系统。本文将对海堤修筑前后两种方案的水动力状况进行比较。本文采用Mike-21模型对研究区的水动力状况进行了模拟。计算区域如下：纬度：1080000-1160000(北纬9o44-10o32)；经度：670000-770000(东经106o33-107o33)。计算中使用的网格是非结构网格，满足了精度和计算细节的要求。将Mike 11模型的输出数据作为模型流量边界的输入数据。利用冯头站的实测水位资料和全球潮汐预报资料对模型进行了定标和验证。研究场地的模型校准和验证持续时间分别为2000年10月17日至2000年10月20日和2000年10月21日至2000年10月24日。标定的参数为海底粗糙度。考虑了无海堤和有海堤两种情况下模型的应用。这两个情景都显示了Go Cong-Vung Tau地区的半日潮汐状况。进一步证实了潮流主要受潮汐和近岸河口水流的影响。海堤的建设形成了两个截然不同的区域：第一区域-水库，包括主堤、支堤和Soai Rap河口；第二区域-甘来湾，包括龙头、Thi Vai河口和支堤。库内两种情景的水动力状况发生了显著的变化，如水位/水流的位相、波动幅度有较大差异。除库内外，库外水位/水流的相位、波动幅度均较小。
The low-lying terrain in downstream area of Sai Gon - Dong Nai river is mostly affected by natural disasters such as flooding, saltwater intrusion causing difficulties in process of socio-economic development. The project of building Vung Tau - Go Cong sea dyke with a length of 32 km was proposed to solve these problems, particularly creating a reservoir for storing water and preventing saltwater intrusion, expanding urban space, industrial parks, tourism, services, shelter for boats from the storm, reserving fresh water in the future. However, hydrodynamic regime in this area would be altered by the construction of Vung Tau - Go Cong sea dyke, causing sedimentation in estuaries, changing salt marsh ecosystems. The comparison between hydrodynamic regimes with two scenarios before and after construction of sea dyke will be mentioned in this paper. In this study, MIKE 21 model was used to simulate hydrodynamic regime in study area. The computed domain is described as follows: Latitude: 1080000 - 1160000 (9o44N - 10o32N); Longitude: 670000 - 770000 (106o33E - 107o33E). The grid which was used in computation was unstructured mesh because it met the requirement of accuracy and detailed computation. Exported data from MIKE 11 model was used as input data for discharge boundary of model. The observed water level data of Vung Tau station and global tide prediction data were used for model calibration and validation. Duration time of model calibration and validation for the research site was from 17/10/2000 to 20/10/2000 and from 21/10/2000 to 24/10/2000 respectively. The calibrated parameter was seabed roughness. The application of model is considered in two scenarios: Without sea dike and with sea dike. Both scenarios show semidiurnal tidal regime in Go Cong - Vung Tau area. Moreover, those confirm that current is mainly influenced by tide and flow of estuaries in coastal area. The construction of sea dike creates two distinct areas: The first area- reservoir including main dike, branch dike and Soai Rap estuary; The second area - Ganh Rai bay containing Long Tau, Thi Vai estuaries and branch dike. There is a significant change in hydrodynamic regime between two scenarios inside reservoir, for example considerable differences in phase, fluctuation amplitude of water level/current. Except for inside the reservoir, there is a small change in phase, fluctuation amplitude of water level/current outside reservoir.