厦门岛黄厝沙滩蚀退的原因与防护工程

黄厝沙滩位于厦门岛的东南岸,长4.2km,走向为NE-SW.东距小金门岛4.6km.南距大担、二担等小岛4km.1956年至2001年的45a间,在优势的NE向风和浪的作用下,沙滩平均每年以约2m的速度后退.近20a来,由于人工挖砂和海岸工程不当等原因,黄厝沙滩受到更严重的破坏.在近年沿岸道路和绿化带的施工中,人为地把原来大于30°坡度的天然侵蚀陡坎削成小于10°并与沙滩连接成一个坡面的缓坡.强台风袭来时,出现了多处沙滩砂不受阻挡地冲越上马路,冲越高程超过黄零8.5～9.0 m.在宽40多米的环岛路上积砂厚达8～10 cm!为了有效地保护黄厝沙滩,防止海岸线继续后退,应当采取挡沙坝或"离岸坝"工程以阻止纵向泥沙搬运,同时在可能出现横向砂冲越上岸的岸段和侵蚀后退严重的岸段修建护岸和挡浪墙工程以阻挡台风时大量海滩砂向陆地冲越.     

厦门岛东南岸沙滩近期剖面变化研究

根据厦门岛东南岸沙滩剖面1999年2月-2002年11月4年的观测资料,分析了该剖面上平均高潮位、平均海平面、平均低潮位的位置变化,绘制了冲淤变化曲线,研究剖面的形态特征及季节和长周期变化趋势。结果表明,风暴潮影响后沙滩剖面呈风暴型剖面,而常浪季节均表现为滩肩型复式剖面。受滨外地形、岸线走向、季节性风浪和潮汐活动等因素影响,沙滩剖面的季节变化比较复杂,长周期变化及风暴潮后剖面的恢复过程各岸段有所不同：泥沙流上游的岸段供沙不足,呈侵蚀状态,剖面恢复较慢;下游则呈基本稳定或淤长状态,剖面恢复相对较快。暴风浪和季节性常风浪交替作用控制着本区沙滩剖面的长周期循环变化过程,该过程一般包括风暴侵蚀期、快速恢复期、稳定恢复期和基本稳定期4个阶段。     

海平面上升情景下辽东湾海岸侵蚀及影响评估

基于海洋站潮位观测和中国沿海海平面变化影响调查等数据,分析了辽东湾沿岸海平面变化及海岸侵蚀状况,并定量评估了未来海平面上升情景下,辽东湾两岸典型沙质海岸侵蚀影响和沙滩养护投入。分析预测和评估结果表明:1980-2017年,辽东湾沿海海平面上升速率为3.0 mm/a,其中辽东湾东岸沿海海平面上升速率明显高于西岸。2009-2017年,辽宁营口白沙湾、绥中网户、绥中南山港和绥中团山气象观测场岸段后退和下蚀较为严重,部分岸段滩肩蚀退达2～3 m/a。预计2100年,辽东湾沿海海平面上升幅度在20～48 cm之间,由海平面上升引发的辽东湾海岸侵蚀土地损失为23.1 km2,土地经济损失为1410万元。为减缓海岸侵蚀,旅游沙滩和一般沙滩养护总投入分别为11亿元和46亿元,全岸段养护成本较高,应选取旅游沙滩等重点岸段进行养护。     

厦门滨海沙滩的养护与海洋旅游业发展的探讨

针对目前厦门滨海沙滩存在的建设总体投入不足、配套设施缺乏、沙滩分布的局限性以及服务经营内容不够丰富和服务手段不够到位的情况,厦门市委、市政府高度重视滨海沙滩质量的提升;为促进滨海旅游经济的发展和实现厦门经济新一轮跨越式发展的目标,先后在厦门岛东部、鼓浪屿东部和同安湾西部提出了多个岸段的滨海沙滩养护的设想,实施沙滩的人工再造和修复.主要定性地针对上述三个滨海沙滩的养护与厦门海洋旅游经济的发展进行探讨,得出滨海沙滩的养护不仅能够有效地防护海滩侵蚀,而且能促进滨海旅游业和城市旅游经济的发展.     

南海区重点岸段海岸侵蚀现状成因分析与防治对策

在2003年与2006年对南海区琼州海峡两岸重点岸段(雷州市徐闻县龙塘镇赤坎村岸段、海南省海口市镇海村岸段和新海村岸段)的海岸侵蚀进行了现场监测,测量了侵蚀的长度、宽度和面积。对两年现场测量结果进行比较分析,结果表明:海岸侵蚀长度的平均速度为200m/a,宽度的平均速度为20m/a,面积的平均速度为4000m2/a。应用了地质分析、水动力分析、极端海洋气候影响分析等新的理论和方法重点分析了海岸侵蚀的成因,并提出了一些对策,供相关部门参考。     

淤泥质海岸形态的演变及形成机制

在淤长型和侵蚀型岸段之间,存在着一种由淤积到侵蚀的过渡型岸段。通过剖面测量、粒度分析和地质调查,认为过渡型岸段具有上部淤积下部冲刷、冲刷逐渐向上部扩展、潮滩表层沉积物不断租化、淤积带逐渐变窄最后过渡到全剖面侵蚀的基本特征和发展趋势。     

杭州湾北岸金山咀—龙泉港岸段近岸滩槽冲淤演变分析

以杭州湾北岸金山咀—龙泉港岸段边滩及海床为研究区域,利用1989—2014年实测及海图资料分析岸滩断面地形变化和岸段冲淤变化。结果表明:在该研究时段,岸段存在长期稳定的冲刷深槽;近岸海床的冲淤表现出“波动性”,5 m等深线(2014年)以浅区以淤积为主,5 m等深线以深冲淤更迭,1989年以来总体呈现冲刷态势。长江入海泥沙量变化为该岸段发生侵蚀/淤积的影响因子之一,台风大浪及海床侵蚀/淤积波的移动导致海床冲淤复杂化。     

设计彩沙示踪法研究滨海沙滩底沙运动--以厦门大学滨海沙滩为例

本文设计彩沙示踪法于厦大滨海沙滩东段进行试验 ,取得了沙粒运动方向、最大运移速度、扩散范围、沿岸输沙率及粒度分异运移状态等定量数据 ,弥补了以往示踪法难以定量分析的缺陷。结果表明 :调查期间 ,厦大滨海沙滩东段沙粒运动是构成厦门岛南岸岸滩在偏东向波浪作用下形成的西南向沿岸漂沙之一个环节 :沙粒大体平行岸线向北运动 ;沙粒沿岸最大运移速度为 2 0 0m/d ;经一个潮周期 ,沙粒向两侧的最大横向扩散距离为 2 0m ,最大垂直扩散深度达 7cm ;岸滩横断面沿岸输沙率为 42 5t/d ;在该岸段沿岸漂沙中 ,粗粒沙偏向低潮带一侧 ,而细粒沙偏向高潮带。     

淤泥质海岸人造沙滩工程评估:以启东碧海银沙沙滩为例

启东碧海银沙沙滩位于长江入海口北支口北侧启东嘴附近,是典型的粉砂淤泥质海岸,受长江江流、海水风暴潮和潮流等影响,海岸地质背景较为复杂,以海陆交互作用的潮间带和水下三角洲地貌为主,本身地质条件并不适合作为沙滩旅游项目的开发。自2011年起,恒大集团在这里使用泥岸人造沙滩技术,通过围堤筑坝、滤沙净水,成功建成了围海7.23 km²、滩长3.5 km的恒大海上威尼斯碧海银沙项目。在该项目建设之前有上海金山城市沙滩、天津东疆浴场、潍坊央子人造沙滩等多个人造沙滩建成,其在上述人造沙滩成功案例的经验基础之上,结合自身地质条件,成功总结出了适合自身的一套围海成湖、吹沙净水、泥沙隔板及防泥网的工程技术系统,为中国粉砂淤泥质海岸人造沙滩建设提供了又一实践经验。     

2020年特大洪水作用下长江口南槽水沙输移特征

径流是影响河口水沙输运的关键动力之一。以长江口为例,历史最大洪水为1954年的92 600m³/s,但以往洪枯季水沙观测期间的大通流量多数小于60000m³/s,对于特大流量情况下的河口水沙输移特征还缺少观测资料和相关研究报道。2020年长江发生了流域性大洪水,大通洪峰流量高达84500m³/s。为认识特大流量情况下的河口水沙输移格局特征,文章基于2020年7月78 300 m³/s流量期间南槽中下段大小潮水沙盐定点观测资料,分析认识到大洪水期间南槽下段水体垂向混合良好,层化发生位置向海外移,表明大流量抑制了盐水入侵。对比分析历史不同流量情况下的南槽区域水沙资料,表明在特大径流作用下,南槽中下段区域盐度和悬沙浓度整体减小,相比在9 900 m³/s （2014年）、17 637 m³/s （2003年2月）和41 450 m³/s （2013）流量下,南槽下段大潮平均盐度分别减小75%、82%和82%,小潮分别减小80%、89%和91...     

9914号台风对厦门岛东南部岸滩的环境效应

1999年14号台风于10月9日正面袭击厦门，最大风力达12级以上（47．1m/s），台风中心在厦门滞留5－6h，全市经济损失十几亿元.本文依据台风前后对厦门岛东南部海岸、沙滩的第一手调查资料以5条固定沙滩剖面多次测量比较进行综合分析。结果表明：人工护岸毁坏1／10以上、岸线后退，沙滩冲淤剧烈、沙源流失严重，海岸与沙滩环境恶化。文中还进一步探讨各种影响因素，提出今后该区域开发利用时应注意事项及防灾措施。     

威海典型海滩沉积地貌及质量评价

选择威海双岛湾附近海滩、国际海水浴场海滩、金海滩、青叽岛以西海滩、青叽岛以东海滩、天鹅湖海滩、桑沟湾海滩、楮岛海滩、南海新区海滩和乳山银滩十处代表性岸滩进行了海滩地貌和底质调查,结合沙滩表层样品分析测试数据,对研究区海滩地貌、沉积物粒度分布特征及海滩质量进行了综合评价。结果表明:威海海滩沉积物主要包括砾砂、粗砂、中砂、细砂四种类型,其中中砂分布最广,约占所有点位的35.6%,细砂、粗砂、砾砂分别占34.4%,26.7%和3.3%。岸滩坡度一般较缓,宽度中等以上,岸滩质量整体较好,部分岸滩受沉积物粒度影响,质量稍差。     

未来海平面上升对厦门海滩侵蚀的测算

本文通过波浪计算和理论海滩剖面方程的拟合,以Ｂｒｕｕｎ模式为基础,根据Ｅｖｅｒｔｓ剖面积分方法,测算了厦门厦门大学海滨浴场、鼓浪屿港 仔后海滨浴场沙滩未来１００ａ海平面上升引起的海滩后退量值。与此同时,计算了Ｂｒｕｕｎ模式的结果。计算结果表明,两处海滨浴 滩的后退值分别为１４．８１和１３．９５ｍ与Ｂｒｕｕｎ模式的结果相当接近。     

深圳大鹏半岛南岸西冲海滩的沉积物来源、平面形态稳定性及横向变化

The coast of the Dapeng Peninsula has been honored as one of "the eight most beautiful coasts in China". The most precious tourism resource for the peninsula is headland bay beaches, among which the beach at Xichong on the southern coast of the peninsula is the longest and the most important one. The information of the stability, sedimentary source and shape change of the beach is very important for maintaining the beach in terms of sustainable development of the peninsula. Heavy minerals in the sand of the beach and the inland stream at Xichong are compared with those of a nearby beach on the same coast to determine the beach sand source; with help of a computer software, MEPBAY, the equilibrium planforms of the beaches on the peninsula are compared with those of an island without rivers to evaluate the stream’s effects on the beach stability; cross shore profiles along the Xichong beach are also surveyed in different seasons of a year to assess the annual shore normal beach changes affected by the stream input, and the relation between the equilibrium planform state and cross shore changes of the beach. It is shown that(1) stream is the main sedimentary source of the beach and the weathering materials of the rocky headlands on both sides of the bay transported by waves are the second source for the beach but it is limited, sand from an inner shelf is not the sedimentary source for the beach at present and was not even during the Holocene transgression;(2) the Xichong beach cannot reach static equilibrium around the entire bay shoreline, the segment of the shoreline where a stream outlet is located is in dynamic equilibrium, and the unstable section occurs in the wave shadow region in the lee of an offshore island;(3) no matter whether the section of the beach shoreline at Xichong is in an equilibrium state or not, it is eroded in the typhoon season and recovered after the season, the maximum change in erosion and accretion occurs in the unstable segment;(4) the Xichong beach can only have small sand body since it is supplied with sand mainly form inland streams, resulting in a possible danger in which sand loss induced by human activities or huge storms cannot be replenished naturally.     

The ecology of sandy beaches of the Benguela ecosystem

Sandy beaches constitute nearly 46 per cent of the coastline between the Cape of Good Hope and the Orange River along the west coast of South Africa. In addition, shores of mixed sand and rock make up a further 24 per cent although these are not considered here. Sandy beaches are therefore the dominant shore type along the coastline, and most are subject to high wave energy. There are two main ecological beach types along the study coastline: those that receive a high input of organic matter in the form of stranded kelp and those that do not. Neither type appears to support large stocks of surf-zone phytoplankton, but despite this, even beaches receiving no stranded kelp bear high standing stocks of infauna. This fact may be related to the location of the beaches alongside a highly productive upwelling region. Existing ecological information on sandy beaches along the Benguela coastline is reviewed and integrated to form a composite picture of present understanding of these beaches. The definition of a sandy beach includes not only the sandy intertidal zone but also the surf zone and sand dunes associated with it. Sandy beaches are characterized by the absence of attached primary producers, although in some parts of the world primary production by surf-zone phytoplankton has been found to be important. Secondary production by the infauna usually depends on matter imported into the system, except on beaches supporting important stocks of surf-zone phytoplankton. Imported organic matter is retained by beach sediments which act as a physical sieve, filtering large quantities of water with each wave and tide.     

厦门岛东海岸沙滩底栖甲藻的种类组成及优势种的季节变化

2001年8月至2002年7月,对厦门岛东海岸黄厝沙滩底栖甲藻的种类组成和优势种的时空分布进行了为每月一次的调查,共鉴定甲藻种类46种,其中底栖种39种,常见种14种,优势种4种.Amphidinium britannicum和Adenoides sp.为冬春季优势种,Herdmania litoraris和Peri-dinium quinquecorne为夏秋优势种,优势种的季节更替比较明显.夏秋季节的种数多,冬春季节的种数少,细胞数量高峰出现在春夏季,秋冬两季数量很少,由夏季的200多个每克干沙减少到冬末的0~4个/g干沙;多样性指数和均匀度呈双峰型分布,峰值出现在10和2月,谷值出现在12月和7月.空间分布上,底栖甲藻的总细胞密度和优势种的细胞密度呈现由高潮带向中、低潮带增加的趋势.分析了影响厦门东海岸沙滩底栖甲藻时空分布的主要因素,并探讨了沙滩底栖甲藻与近岸赤潮及着色砂现象的关系.     

厦门岛东南部海岸演变与泥沙输移

通过海岸地貌调查、沉积物分布、岸线对比、沿岸输沙率计算等手段，分析研究了厦门岛东南部海岸海滩的演变特征，认为厦门岛东南部海岸的沿岸净输沙方向是由东北向西南，由东向西；黄厝湾中北部存在反向输沙。文中划分了中－强侵蚀海岸、中侵蚀海岸、中－弱侵蚀海岸、弱侵蚀海岸、弱淤积海岸和不确定海岸等6种类型。人工采沙是引起海岸侵蚀的最重要因素之一。     

The biomass of macro- and interstitial fauna on clean and wrack-covered beaches in Western Australia

The benthic faunal spectrum including bacteria, protozoans, meiofauna, wrack epifauna and macrofauna, was quantitatively surveyed on two modally reflective, moderate energy, Western Australian beaches. The more exposed beach had coarser sand, no intertidal macrofauna and a poor interstitial fauna. The less exposed beach had a large deposit of wrack totalling 161 kg m^?1 dry mass concentrated on the lower shore. The amphipod Allorchestes compressa was abundant in the fresh wrack comprising most of the macrofauna. There were also fairly abundant small epifauna on the wrack. Dry biomass of macrofauna, epifauna, meiofauna, protozoans and bacteria was 0, 0, 15, 4 and 180 g m^?1 on the more exposed beach and 160, 3, 112, 9 and 901 g m^?1 on the less exposed beach with wrack. On the latter beach there was an inverse correlation between meiofaunal densities and the densities of protozoans and bacteria, suggesting grazing by the former on the latter. On both beaches meiofauna was concentrated in the mid- to upper beach, protozoans near the surface and bacteria in the mid- to lower beach. It is estimated that bacteria are responsible for most of the secondary production on both beaches.     

The distribution and behaviour of tar balls along the Israeli coast

A fortnightly sampling of tar balls on six beaches along the Israeli coastline between 14 April 1975 and 25 June 1976 showed that the mean content of tar during that period was 3625 g m^?1 of beach front. The northern and central parts of the coast were significantly more polluted than the southern part. Between July 1975 and February 1976 the mean tar quantity decreased continuously from 5635 to 1344 g m^?1.A comparison of tar quantities on the Israeli beaches with those of other beaches in the world showed that the Israeli beaches are more polluted than those of the west Atlantic coast, are as polluted as other beaches on the eastern coast of the Mediterranean Sea, and are less polluted than the beaches of Alexandria, Egypt, and Paphos, Cyprus. It is suggested that the tar content on the beach is related to the degree of oil pollution in the sea. The closer a beach is to an oil shipping lane or an oil dumping site, the heavier it is polluted.During storms, beach tar balls are pushed by the waves to the back of the beach or, in the case of a cliffed coast, are carried along the shore by the longshore current. When the tar balls reach a gap in the cliff (such as an estuary), they are carried inland by the storm waves. There the tar may become buried or dry, shrink and break into small particles which are then dispersed by the wind.