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1 前言在浅滩区 ,沉积物搬运过程对海滩地貌及海岸线变迁有相当重要的意义。其最终的结果是 ,沉积物的净搬运方向决定了海滩现在所处的状态 ,侵蚀状态、淤积状态还是处于平衡状态(Hughes等 ,1 997)。潮间浅滩波浪的往复运动 (即向岸运动和离岸运动 )为沉积物的横向搬运提供了动力。波浪向岸运动时 ,沉积物也向海岸移动 ;反之 ,波浪离岸运动时 ,沉积物也离岸移动。在整个过程中 ,水动力条件相当复杂 ,如作用在海底面上的破碎波或非破碎波的形变 (Guza和Thorn ton,1 982 ;Kobayashi等 ,1 987)。同时 ,波浪运动也与海滩地下水相互作用。在波… 相似文献
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大沽河是青岛市重要的供水源之一,了解大沽河流域水循环的过程和机理有助于合理地利用大沽河流域水资源。为了研究大沽河流域地下水循环的规律,在大沽河李哥庄镇至胶东镇段研究区内采集了26个地下水样本和4个地表水样本,测定其氢、氧同位素及水化学成分,通过分析其变化特征初步判定地下水补给来源以及影响因素。对降水和地下水中的稳定同位素组成(δD,δ~(18)O)进行分析,结果表明大气降水是该区域地下水的主要来源。地下水及地表水的水化学结果表明研究区地下水类型多样,主要为HCO_3-Cl-SO_4-Ca-Na,Cl-SO_4-Na,Cl-HCO_3-SO_4-Na,HCO_3-Cl-SO_4-Na-Ca-Mg,Cl-Na五类;地表水受到强烈的蒸发浓缩作用,并在一定程度上补给了地下水。同时,地下水中的氢、氧同位素含量与Cl~-和TDS区域分布特征相互佐证,证明地下水化学成分主要受到海水入侵的影响,其次为围岩矿物的溶解。 相似文献
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华南海岸岬间海滩地形动力状态类型研究 总被引：1，自引：0，他引：1
海滩地形动力状态分类对于理解近岸带动形动力过程、海滩浴场风险评估等方面有重要的意义。收集了华南51个岬间海滩波高、波周期、潮差和泥沙粒径等地形动力要素特征值,利用分层聚类分析方法,同时结合海滩相对潮差分类模型,对华南岬间海滩的类型进行了探讨,结果表明:(1)华南岬间海滩可以聚类成7个类型。通过与相关的现场观测比较,各类型在地形组合上具有各自的显著特征;(2)聚类分析结果能很好的区分中到大潮差海岸与小潮差海滩之间的差异,与相对潮差模型结果一致。对于小潮差海滩,聚类结果与相对潮差模型有一定的差异,表明华南小潮差海滩的分类还需要进一步深入研究。 相似文献
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一般认为滩角是近岸带泥沙、水动力和地形耦合作用的产物,对近岸带特别是碎波带和冲流带的动力变化响应迅速,还可以反映海滩状态,但具体的成因一直得不到很好的解释.首先详细介绍了关于滩角成因的争论以及自组织机制理论,其中驻立边缘波假说和自组织机制假说是最为认同的两种滩角成因假说.基于WERNER(1993)提出的滩角形成的自组织机制假说,建立包含冲流动力、泥沙输运和地形演变的滩角形成和发育的元胞自动机模型.模型中修正了以前研究中的坡度参数表达式和水动力输入方式.经过200个冲流循环的数值模拟,原来平直的滩面上形成了明显的滩角形态,滩角间距约为5.5～6.0 m,520个循环周期后,滩角形态基本上达到稳定状态.对模拟过程进行分析,结果表明:(1)模拟得到的滩角形态比先前的研究结果更接近天然状态下的滩角;(2)随机的水质点冲流运动使海滩地形呈无规律变化,但通过动力、泥沙、地形之间的反馈过程逐渐形成了滩角地形;(3)滩角形成过程中,海滩基本上处于堆积过程中.开始堆积速度较快,当滩角形态达到准平衡状态时(大约300个循环后),海滩体积增速变慢,并逐渐地达到稳定状态,海滩体积变化呈现小的波动调整;(4)模拟得到的有效冲流距离(S)和滩角间距(λ),满足滩角自组织机制假说的基本关系.因此,可以认为滩角是在海滩泥沙、地形与波、流的自组织过程中形成的,是一种堆积地形.自组织理论为从不同的侧面认识和研究海岸带现象与过程提供一扇窗口,是一个值得研究的方向. 相似文献
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地下水库人工补给的模型研究--以大沽河地下水库为例 总被引：1，自引：0，他引：1
为使地下水库在丰水季节获得足够补给,利用Visual Modflow 软件,在分析地下水库水文地质条件的基础上,概化出该区水文地质概念模型,运用准三维地下水水流模型,通过有限差分方法对地下水库的地下水系统进行了模拟,拟合结果表明, 地下水位的计算值与实测值拟合程度较好,模拟出的地下水流场与实际情况基本一致.利用校正好的模型,分析了橡胶坝渗漏补给的动态变化规律,并针对橡胶坝的补给,通过数值模拟探讨了坝内蓄水因工业开采而激发的渗漏补给量.结果显示,橡胶坝的渗漏补给量在枯水期（2～5月份）逐渐增大,而在平水期（9～12月份）逐渐减小;激发补给量与激发开采量的比值呈现上升趋势,同时随着激增补给量的迅速增大,激发补给量与开采增加量的比值随工业开采量的增加而逐渐增大,这说明傍橡胶坝取水可使更多的地表水入渗补充地下水,从而有效地提高水资源的利用率. 相似文献
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《中国海洋大学学报(自然科学版)》2021,(Z1)
通过在十二月份对三亚市南部海滩(大东海海滩、亚龙湾海滩、三亚湾海滩)进行采样分析,并对45个表层砂样品进行室内试验,分析了各海滩表层砂的粒度特征。结果表明:研究区的3个海滩的表层砂均为细砂,但不同粒径颗粒组分差异明显,其中亚龙湾海滩的粗砂及中砂含量明显高于大东海海滩、三亚湾海滩,亚龙湾海滩表层砂最粗,大东海海滩次之,三亚湾海滩最细;3个海滩呈现由岸向海、由东向西海滩表层砂平均粒径有逐渐减小的趋势;3个海滩均表现为分选较好,级配良好。同时,运用MIKE21软件的SW模型对三亚市南部近岸海域的波浪进行模拟,用于分析波浪对冬季海滩表层砂粒度特征的影响。 相似文献
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海滩和岸线数据时空连续模拟 总被引：1，自引：0，他引：1
海岸科学家利用多种统计方法获得海滩和近岸系统的长期时空动力学知识的同时 ,仍有一小部分研究工作是针对海滩和海岸线数据的时空连续性模拟的。本文将利用 Box-Jenkins的模拟程序 ,对从加拿大艾略湖鲍恩特·普利东北部海滩收集的海滩和岸线数据的长时间连续模拟进行最佳描述。在介绍 Box-Jenkins模拟程序和结果之前 ,本文对研究范围和数据收集的方法作简短的描述。1 东北部海滩研究范围鲍恩特·普利位于 40 s平行线的南部 ,向艾略湖的西部盆地延伸 1 0 km(图 1 )。鲍恩特·普利包含一个大沼泽地 ,侧面被海滩包围 ,其中包括东北部的海滩… 相似文献
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海滩养护是近年来国内外备受推崇的海岸防护措施。我国“十二五”规划中对于海岸防护及岸线恢复工作更加重视,加强海滩养护相关理论和技术问题的总结和评估是进一步做好此项工作的关键。文章回顾了海滩养护法在国内外的开展情况及有关海滩养护剖面设计的理论、物理和数值试验研究进展,分析了目前在海滩养护剖面研究及设计中存在的问题并指出：目前我国海滩剖面演变研究主要应用地质、地形学分析方法,应强调从水动力学角度研究泥沙与岸滩冲淤变化过程的关系;海滩养护设计中简单应用Dean的平衡剖面模式对补滩剖面进行设计存在很大不足,应从实际海滩剖面地形结构、滩面泥沙组成与输移和波浪运动特征等方面寻求改进与提高。 相似文献
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修建海岸水库是满足滨海地区淡水资源的保障的一个重要方式,为了进一步分析海岸水库的建立对滨海含水层的海水入侵的影响,采用SUTRA(saturated-unsaturatedtransport)模型建立具有代表性的二维海岸模型开展定量和定性研究,结果表明:潮汐作用抑制底层盐水楔的入侵,加快海陆物质交换;实例中计算表明建坝后,海岸水库坝体的建立加剧了海水入侵;水库水位在平均海平面以下时,潮汐动力因素占主导,海水入侵严重且随着水位抬高,海水入侵程度基本保持不变,应注意海水入侵的防治;库区水位在平均海平面以上时,海水入侵程度随着库区水位的抬高而减少,可以调节水库水位进行滨海含水层的海水入侵的防控;海岸水库在建设中存在一个控制水位,当水库水位在控制水位以上,库区水体盐度和含水层淡水储量能得到保证;库区高水位时内陆物质运移时间较长,运移区域较广,氮类污染物易在库底含水层堆积,需重视含水层的地下水污染防治。 相似文献
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This paper demonstrates the importance of advective transport of water through permeable estuarine and salt marsh sediments. This transport delivers significant quantities of radium and barium to the coastal ocean; and, in some cases may remove significant quantities of uranium. These conclusions are based on repeated analyses of seven river–estuarine systems from North Carolina to Florida. Fluxes of radium and barium from these river systems are shown to be inadequate to balance the dissolved inventories of these elements in the South Atlantic Bight. The strong interactions that occur between surface and subsurface waters as these rivers encounter coastal marshes lead us to consider these river mouths as marsh-dominated in terms of their chemical fluxes to the ocean. Such interactions between the river and coastal marsh must be considered when estimating fluxes of material between the land and ocean. 相似文献
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海滩侵蚀的数值分析模型 总被引：3，自引：0，他引：3
介绍了有关海滩侵蚀造成海岸演变问题的数学分析模型。根据海岸线演化和海滩断面的沉积物迁移理论建立一种顺岸方向和垂直岸线方向海岸形状变化的耦合模型。将海滩沉积物被海浪迁移的机理看作由于海水在海滩介质孔隙内渗流侵蚀和海浪对海滩介质冲刷所致的海滩介质的孔隙损伤变化。这种结合数值和解析分析的综合方法可用于模拟海岸演变问题中海岸线 (沿岸方向 )和海滩断面 (垂直海岸线方向 )的变迁情况 相似文献
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Owing to lack of observational data and accurate definition,it is difficult to distinguish the Kuroshio intrusion water from the Pacific Ocean into the South China Sea(SCS).By using a passive tracer to identify the Kuroshio water based on an observation-validated three-dimensional numerical model MITgcm,the spatio-temporal variation of the Kuroshio intrusion water into the SCS has been investigated.Our result shows the Kuroshio intrusion is of distinct seasonal variation in both horizontal and vertical directions.In winter,the intruding Kuroshio water reaches the farthest,almost occupying the area from 18°N to 23°N and 114°E to 121°E,with a small branch flowing towards the Taiwan Strait.The intrusion region of the Kuroshio water decreases with depth gradually.However,in summer,the Kuroshio water is confined to the east of 118°E without any branch reaching the Taiwan Strait;meanwhile the intrusion region of the Kuroshio water increases from the surface to the depth about 205 m,then it decreases with depth.The estimated annual mean of Kuroshio Intrusion Transport(KIT) via the Luzon Strait is westward to the SCS in an amount of –3.86×106 m3/s,which is larger than the annual mean of Luzon Strait Transport(LST) of –3.15×106 m3/s.The KIT above 250 m accounts for 60%–80% of the LST throughout the entire water column.By analyzing interannual variation of the Kuroshio intrusion from the year 2003 to 2012,we find that the Kuroshio branch flowing into the Taiwan Strait is the weaker in winter of La Ni?a years than those in El Ni?o and normal years,which may be attributed to the wind stress curl off the southeast China then.Furthermore,the KIT correlates the Ni?o 3.4 index from 2003 to 2012 with a correlation coefficient of 0.41,which is lower than that of the LST with the Ni?o 3.4 index,i.e.,0.78. 相似文献
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基于MIKE FLOOD建立秦皇岛入海河流及其近岸海域一维、二维耦合河流-海岸水动力和水质模型,研究了秦皇岛海域和入海河流的水动力和污染物分布规律。结果表明:(1)海域潮流为半日潮,其中石河口南北支入海口流速变化过程差别较大,但水位变化过程基本一致;(2)整体上河流入海口化学需氧量(COD)与流速呈正相关关系;(3)COD在近岸海域的扩散方向与涨落潮潮流方向一致,各入海河口海域落潮流期间的COD高于涨潮流。如上结论为赤潮爆发机理和应急处置研究提供科学依据和技术支持。 相似文献
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岬湾相间的琼州海峡南岸在海岸动力条件作用下,岸滩发生侵蚀或堆积,特别是南岸中部的南渡江三角洲沿岸岸滩演变剧烈。该文从海岸动力地貌的角度,对琼州海峡南岸的海岸动力特征、泥沙运动以及岸滩演变进行分析。根据海峡南部三维潮流场数值模拟结果,结合经验公式初步分析潮流引起的泥沙运移速率和方向,得到岸外水域总的泥沙运移趋势为从西向东。根据波浪动力计算分析沿岸泥沙运移,探讨沙质岸滩的动态与地貌演变之间的关系,得出海峡南岸海岸地貌演变与盛行的NE和NNE向风浪有密切关系,岸滩的演变过程主要受制于这两个方向的风浪及其引起的泥沙沿岸运移。 相似文献
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Three-dimensional hydrodynamic-eutrophication model (HEM-3D): application to Kwang-Yang Bay, Korea 总被引：9，自引：0，他引：9
The purpose of this paper is twofold: to describe the water quality model of Three-Dimensional Hydrodynamic-Eutrophication Model (HEM-3D) and to present an application of HEM-3D to a coastal system in Korea. HEM-3D, listed as a tool for the development of Total Maximum Daily Load by US Environmental Protection Agency, is a general-purpose modeling package for simulation of the flow field, transport, and eutrophication processes throughout the water column and of diagenetic processes in the benthic sediment. This paper describes the water quality model of HEM-3D with emphasis on its unique features. Excessive loadings of organic wastes have significantly deteriorated water quality conditions of Korean coastal waters. This paper presents an application of HEM-3D to Kwang-Yang Bay, a coastal system in Korea, which is one of the first water quality modeling efforts for Korean coastal waters accompanied by a relatively comprehensive field program. The current status of data availability for water quality modeling in Korea is discussed. 相似文献
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A model study of influence of circulation on the pollutant transport in the Zhujiang River Estuary and adjacent coastal waters 总被引：1，自引：1，他引：1
A tracer model with random diffusion coupled to the hydrodynamic model for the Zhujiang River Estuary (Pearl River Estuary, PRE) is to examine the effect of circulations on the transport of completely conservative pollutants. It is focused on answering the following questions: (1) What role does the estuarine plume front in the winter play in affecting the pollutants transport and its distribution in the PRE? (2) What effect do the coastal currents driven by the monsoon have on the pollutants transport? The tracer experiment results show that: (1) the pollutant transport paths strongly depend on the circulation structures and plume frontal dynamics of the PRE and coastal waters; (2) during the summer when a southwesterly monsoon prevails, the pollutants from the four easterly river inlets and those from the bottom layer of offshore stations will greatly influence the water quality in Hong Kong waters, however, the pollutants released from the four westerly river-inlets will seldom affect the water quality of Hong Kong waters due to their transport away from Hong Kong; (3) during the winter when a northeasterly monsoon prevails, all pollutants released from the eight river gates will be laterally transported seaward inside the estuary and transport westward in the coastal waters along the river plume frontal zone. However, pollutants released from the surface layer of offshore stations near or east of the Dangan Channel will be carried into the coastal waters of Hong Kong by the landward component of the westward coastal current driven by the winter northeasterly monsoon. But the pollutants from the bottom layer of the offshore stations will be carried away from the offshore by the bottom flow driven by the northeasterly monsoon. This implies that only surface-released matter from offshore stations will affect the water quality of the coastal waters around Hong Kong during the winter when a northeasterly monsoon prevails. 相似文献
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A tracer model with random diffusion coupled to the hydrodynamic model for the Zhujiang River Estuary (Pearl River Estuary, PRE) is to examine the effect of circulations on the transport of completely conservative pollutants. It is focused on answering the following questions: (1) What role does the estuarine plume front in the winter play in affecting the pollutants transport and its distribution in the PRE ? (2) What effect do the coastal currents driven by the monsoon have on the pollutants transport? The tracer experiment results show that: (1) the pollutant transport paths strongly depend on the circulation structures and plume frontal dynamics of the PRE and coastal waters; (2) during the summer when a southwesterly monsoon prevails, the pollutants from the four easterly river inlets and those from the bottom layer of offshore stations will greatly influence the water quality in Hong Kong waters, however, the pollutants released from the four westerly river-inlets will seldom affect the water quality of Hong Kong waters due to their transport away from Hong Kong; (3) during the winter when a northeasterly monsoon prevails, all pollutants released from the eight river gates will be laterally transported seaward inside the estuary and transport westward in the coastal waters along the river plume frontal zone. However, pollutants released from the surface layer of offshore stations near or east of the Dangan Channel will be carried into the coastal waters of Hong Kong by the landward component of the westward coastal current driven by the winter northeasterly monsoon. But the pollutants from the bottom layer of the offshore stations will be carried away from the offshore by the bottom flow driven by the northeasterly monsoon. This implies that only surface-released matter from offshore stations will affect the water quality of the coastal waters around Hong Kong during the winter when a northeasterly monsoon prevails. 相似文献