基于FVCOM的福建连江海域水质数值模拟

发布时间：2018-03-02 19:23

  本文选题：FVCOM　切入点：连江　出处：《国家海洋环境预报中心》2017年硕士论文　论文类型：学位论文

【摘要】：最近几十年间,近岸的生活垃圾和工业废物、废液的排放加剧了近岸水体的富营养化,造成赤潮频发,对近岸海水渔业养殖造成了很大的经济损失,破坏了沿海区域的可持续发展。建立水动力-水质耦合模型,能够有效地预测水质状态变量的变化趋势,为近岸渔业养殖提供技术支撑。本文基于FVCOM(An Unstructured Grid,Finite-Volume Coastal Ocean Model)模型建立了较高分辨率的福建连江海域水动力模型,在验证结果较好的基础上,建立三维水动力-水质耦合模型。模型验证结果能较好的模拟福建连江海域的水位、温度、流场等物理量,能基本的模拟出叶绿素a、溶解氧、营养盐等水质状态变量的时空分布特征。并且利用WASP(The Water Quality Analysis Simulation Program)模型公式建立零维模型,针对浮游植物进行参数敏感性实验。本文的主要研究结果如下:(1)该海域是规则半日潮类型,潮波主要沿着福建东南沿海自东北向西南方向传播,越靠近岸边,振幅越大;同潮图中的等振幅线和等迟角线在近岸海域基本垂直,有逆时针旋转的驻波系统的特性。最大可能潮差与岸线走向基本平行,从5.5m左右逐渐增大到三沙湾、兴化湾的湾口,约为8.5m左右,从湾口向湾内逐渐增加到9m左右。(2)该海域的潮流类型在平潭以北属于规则半日潮流类型,平潭以南属于不规则半日潮流类型;靠近岸线区域的研究区域,表现为往复流,在兴化湾、平潭、闽江以外海域表现为旋转流。潮流椭圆图显示,半日分潮流、全日分潮流多数为逆时针旋转。(3)潮位验证的平均绝对误差小于0.2m,海流流速平均绝对误差小于0.08m/s,流向平均绝对误差小于30°,温度平均绝对误差小于1℃。(4)水质状态变量中溶解氧数值模拟结果与浮标数据对比,其平均绝对误差在0.32mg/l,并基于模拟结果分析了春夏季的月平均叶绿素a、硝酸盐和亚硝酸盐、活性磷酸盐的时空变化特征。(5)对浮游植物进行参数敏感性实验,结果表明敏感度较高的参数包括:最大生长率、浮游植物死亡率、浮游植物呼吸作用率。
[Abstract]:In recent decades, the discharge of domestic refuse and industrial waste from coastal waters has aggravated eutrophication of coastal waters, caused frequent red tide, and caused great economic losses to coastal mariculture. The coupling model of hydrodynamics and water quality can effectively predict the change trend of water quality state variables. Based on the FVCOM(An Unstructured Gridite Volume Coastal Ocean Model, a high resolution hydrodynamic model of Lianjiang Sea area in Fujian Province was established. The model can simulate the water level, temperature and flow field of Lianjiang River, Fujian Province, and can simulate chlorophyll a, dissolved oxygen, etc. The spatial and temporal distribution characteristics of water quality state variables such as nutrient and salt, and the zero-dimension model are established by using the WASP(The Water Quality Analysis Simulation program formula. The main results of this paper are as follows: (1) the sea area is a regular semi-diurnal tide type, and the tidal wave propagates mainly from northeast to southwest along the southeast coast of Fujian Province, and the amplitude increases with the approaching to the shore. The isometric and isobaric lines in the same tide map are basically perpendicular to the coastal waters and have the characteristics of counterclockwise rotating standing wave systems. The maximum possible tidal range is basically parallel to the direction of the shoreline, gradually increasing from about 5.5 m to Sansha Bay, the mouth of Xinghua Bay. About 8.5 m, gradually increasing to about 9 m from the mouth of the bay to about 9 m.) the tidal current type in this area belongs to the regular half-day tide type north of Pingtan, the irregular half-day tidal current type to the south of Pingtan, and the study area near the shoreline area. It is shown as a reciprocating current, and in the waters off Xinghua Bay, Pingtan and Minjiang River it appears as a rotating current. The elliptical chart of tidal current shows that the half-day tidal current, The mean absolute error of tide level verification is less than 0.2 m, the mean absolute error of current velocity is less than 0.08 m / s, the mean absolute error of flow direction is less than 30 掳, and the absolute error of temperature is less than 1 鈩，

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