泥沙研究

口门整治、采砂和航道疏浚等高强度人类活动引起珠江河口磨刀门滩槽格局剧烈变化，磨刀门治理与保护面临新的挑战。通过地形资料分析、数学模型和物理模型等手段研究发现：2011年以来，采砂致使磨刀门中心拦门沙大幅萎缩，磨刀门出口由东西两槽演变成单一出口格局；随着口门的外移及河流海洋动力的变化，磨刀门河口有从河流-波浪型口门向浪控型口门进一步转变的趋势，未来口门仍会形成新的拦门沙，且可能引起口门水流不畅、两侧海岸侵蚀；考虑磨刀门拦门沙修复对防咸、消浪及通航具有正向作用，初步提出松木桩围合促淤的拦门沙修复方案，并进行拦门沙促淤物理模型试验，以期实现弱人工干预下的拦门沙自然修复。

The intensive human activities such as estuarine regulation sand extraction, and channel dredging have caused significant changes in the morphology of the Modaomen estuary in the Pearl River Estuary, presenting new challenges for the management and protection of the estuary. Through analysis of topographic data, mathematical models, and physical models, it has been found that: the central sandbar at Modaomen estuary has shrunk significantly due to sand extraction since 2011. The outlet pattern of Modaomen has evolved from a dual-channel on the east and west into a single channel. As the outlet moves seaward and the changes in riverine and marine dynamics, is the Modaomen estuary shows a trend of further transformation from a river-wave controlled to a wave-dominated estuary, and the new sandbars will also form in the future, which may cause the flow unsmooth through the outlet and erosion on the adjacent coasts. Considering the positive effects of restoring the sandbar at Modaomen on saltwater intrusion prevention, wave dissipation, and navigation, a preliminary sandbar remediation plan has been proposed. Physical model experiments have been conducted to promote sediment deposition and aim to achieve natural restoration of the sandbar under weak human intervention.