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受波浪掀沙作用影响,河口边滩工程促淤效果的合理预测始终是工程泥沙研究的难题之一。在文献[1]提出的淤泥质河口边滩促淤后淤积预报模式的基础上,就波浪作用对工程促淤效果影响进行了研究。通过建立长江口—杭州湾海域的平面二维水沙数学模型和波浪模型,计算不同波浪场作用下促淤工程区泥沙淤积强度。藉此,定义了波浪作用引起的淤积影响系数k0,并建立了系数k0与相对波高(波高水深)的关系。由此,结合促淤区内分级波浪数值模拟结果,给出了综合反映促淤区1 a内各级波况的影响系数统计平均值k0,并将k0代入文献[1]提出的淤泥质河口边滩促淤后淤积预报模式,结果表明促淤区年淤积强度计算值与实测值吻合较好。 相似文献
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In order to study the influence of wind mixing on the spring variability of the plankton production of the north western Corsican coastal area, a one-dimensional (1D), vertical, coupled hydrodynamic/biological model (ECOHYDROMV) is used. A hydrodynamic 1D model of the water column with a k–l turbulent closure is applied. The biological model comprises six state variables, representing the plankton ecosystem in the spring period: phytoplankton, copepods, nitrate, ammonium, particulate organic matter of phytoplanktonic origin and particulate organic matter of zooplanktonic origin. The system is influenced by turbulence (expressed by the vertical eddy diffusivity), temperature and irradiance. The model takes into account momentum and heat surface fluxes computed from meteorological data in order to simulate a typical spring atmospheric forcing for the considered area. Results show that primary production vertical structure is characterised by a subsurface maximum which deepens with time and is regulated by the opposite gradients of nitrate concentration and irradiance. Surface plankton productivity is mainly controlled by turbulent vertical transport of nutrients into the mixed layer. The short time scale variability of turbulent mixing generated by the wind appears to be responsible for the plurimodal shape of plankton blooms, observed in the considered area. Furthermore, the model is applied to the study of the spring evolution of the plankton communities off the bay of Calvi (Corsica) for the years 1986 and 1988. In order to initiate and validate the model, time series of hydrological, chemical and biological data have been used. The model reproduces accurately the spring evolution of the phytoplankton biomass measured in situ and illustrates that its strong variability in those years was in close relation to the variability of the wind intensity. 相似文献
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东营黄河公路大桥是黄河干流上濒临入海口的最后一座特大型桥梁,桥位河段水文条件十分复杂。该文论述了桥位河段设计流量、水位、河道冲淤、防凌、通航要求和小浪底工程的影响等桥渡水文要素和桥梁设计的控制条件。 相似文献
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该文介绍了山东省胶南市的防洪现状及历史灾害发生情况,分析了胶南市防洪存在的问题,结合胶南市现状地理条件及实际情况,对胶南市防洪规划的原则及重点进行了阐述,并分析了胶南市进行防洪规划的意义和必要性。 相似文献
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鲅鱼圈港近海区沉积特征及岸坡演变分析 总被引:1,自引:1,他引:0
在现场调查、底质取样分析、海图比较的基础上 ,对本区沉积特征、泥沙运移趋势、水下岸坡演变及港口建设对电厂取水口的影响等进行了分析 ,认为本段海岸多年处于稳定状态 ,沙源有限 ,1港池的建设对电厂取水口水深的维护有一定的影响 . 相似文献
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王明霞 《广州航海高等专科学校学报》2008,16(3):32-34
邓世昌是中日甲午海战中涌现出来的一位民族英雄,探讨他的海防观的形成及爱国主义思想具体表现,对大力弘扬民族精神,把握社会主义核心价值体系精神有重要的意义. 相似文献