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1.
莺歌海三莺村岸段人工沙滩工程岸线数值模拟以及模型的验证方 总被引：1，自引：0，他引：1
以乐东莺歌海三莺村岸段人工沙滩工程为例,其完工1年后的岸线监测结果,表明需要进一步对人工沙滩后的海滩岸线演变进行研究分析。通过GENESIS岸线演变模型模拟人工沙滩后的岸线变化,并尝试采用3种方法对模型进行验证。经过验证后,对人工沙滩工程后1年、3年、5年岸线变化进行了模拟分析。研究结果表明:GENESIS岸线演变模型对于包围型(拦沙堤和离岸堤结合方式)人工沙滩工程是适用的。工程完工1年后,补沙岸线形成了侵淤变化的凹凸弯曲岸线,侵淤幅度不大,5年后侵淤幅度变缓,开始逐渐趋于平衡。据此,也为人工沙滩后期的养护、补沙防护工作起到重要的参考作用。 相似文献
2.
Numerical study of shoreline changes by emergency beach nourishment project at the Middle Beach of Beidaihe, China 总被引：1，自引：1，他引：0
ZHANG Yu HE Lulu KUANG Cuiping PAN Yi GU Jie YANG Yanxiong ZHANG Jiabo 《海洋学报(英文版)》2012,31(1):125-133
Beach nourishment is a common coastal management strategy used to protect beach from erosion along the sandy coastlines. This method has been successfully applied to an emergency project at the West Beach of Beidaihe in the summer of 2008 and the full West Beach nourishment project in 2009-2010, which is the direct base of this study. Some basic information about the emergency engineering area at the Middle Beach is firstly described. The shoreline change of this area, including the analysis of beach width in five monitoring profiles in the bathing places of Middle Beach, is then discussed. After that a numerical model based on one-line theory is established and the numerical results agree well with the measured shorelines, which indicates that the model is appropriate and is qualified to predict the shoreline change of the Middle Beach. With the same model and parameters, long-term performance of the project is predicted, and the result shows that without follow-up nourishment and project, the bathing places can remain suitable for bathing for about 10 a. It is suggested to nourish the beach in time and carry out the beach nourishment project for the full Middle Beach in Beidaihe. 相似文献
3.
人工岛建设在缓解滨海人地矛盾的同时带来新的环境问题。本研究聚焦人工岛建设引起的岸滩侵蚀与泥沙分配失衡问题,以海口西海岸为例,建立GENESIS岸线演变模型,探讨人工岛影响下的海滩地貌演化机制,并在此基础上提出“循环养护”的海滩修复对策。主要研究结论为:①海口湾南海明珠人工岛对邻近海滩的影响以“岛后方淤积、两侧侵蚀”为显著特征,且两侧侵蚀热点区的响应幅度存在明显差异。五源河口至新国宾馆岸段侵蚀更为强烈的主导因素为物源匮乏与岸线形态外凸。②通过人工补沙与循环养护相结合的生态修复措施,可实现岸滩泥沙的合理分配与地貌的动态平衡,有效缓解人工岛引起的海岸侵蚀问题。本研究成果可为国内相似类型海岸的岸滩修复提供良好的借鉴意义。 相似文献
4.
由于自然因素和人类活动的影响等原因,世界很多海滩经受着侵蚀和破坏。而利用人工养护工程来保护和恢复海滩具有养护效果较明显、干滩面积明显增加以及不破坏环境景观的优点,目前得到越来越多国家的认可。国外由于养滩历史较久,养滩工程后的监测和质量评价不仅开展得早,而且已经成为工程的一个重要部分。评价指标已经比较完善,甚至有些国家已经将养滩效果评价列入法规框架之中。我国的海滩养护工程在十几年前才开始,虽然工程量逐年增长,但是对海滩养护工程施工后的工程监测和工程评价却较少涉及。本文对美国、荷兰、英国、丹麦以及我国等国家的海滩养护工程的工程评价工作进行总结,从而提出适用于我国工程特点的养滩工程质量评价因子和方法。 相似文献
5.
潜式人工岬头和离岸式人工岬头是两种改良式人工岬头,与传统人工岬头相比,它们对岸滩的保护效果稍弱,但能改善岬湾内的水交换。以北戴河西海滩养滩工程为研究对象,采用数值模拟的方法,对潜式岬头和离岸式岬头的护滩效果和改善水交换效果进行研究比较。首先建立岸线演变模型和物质输运模型,对工程后的岸线演变及水交换情况进行模拟。岸线演变的模拟结果表明,潜式岬头和离岸式岬头的护滩效果均较好,但潜式岬头后的岸线形状相比离岸式岬头后更为平滑。同时讨论海滩的侵蚀和淤积特性对潜式岬头和离岸式岬头的影响以及潮汐条件对冲淡时间的影响。与传统岬头相比,潜式岬头和离岸式岬头可以很好地减少岬后冲淡时间以及改善岬湾内水交换,而护滩效果只是稍有减弱。因此,潜式岬头和离岸式岬头都是改善岬湾水交换的有效工程措施。 相似文献
6.
Numerical models for shoreline evolution have been used for coastal management planning for several decades. The model calibration is a start point to project shoreline scenarios and in this aim the use of data acquired within the scope of monitoring programmes provides the opportunity to assess the models' capabilities under real condition. This work applies calibration data (retrieved from field surveys) to numerical models to predict medium-term shoreline evolution using, as a case study, a beach stretch named AC, about 3.5 km long and located downdrift of a groin on the northwest Portuguese coast. A smaller stretch AB (2.4 km long), included in the total one, which exhibits a pronounced erosive tendency usually better reproduced in shoreline evolution models, was also analysed. Based on topographic surveys, associated wave climate conditions registered between 2003 and 2008 and typical wave conditions registered over a longer wave climate time period, this work compares the calibration of two different shoreline evolution models, Long-term Configuration (LTC) and GENESIS for this period. Then, considering the 2003 topographic conditions for the models' calibration, the results of both models are discussed with respect to simulation scenarios after 10, 15 and 20 years of evolution. The 10-year evolution projections of the models are also compared to the results of a survey performed in February 2012. For the wave data calibration period (2003–2008), the average shoreline retreat of the analysed coastal stretch was reproduced with small differences (around 1% and 10% for LTC and 15% and 14% for GENESIS, considering stretches AB or AC, respectively), though local differences along the AB coastal stretch represent root mean square errors reaching up to 52% and 88% for GENESIS and LTC, respectively, and were above 118% for both models along the AC coastal stretch. 相似文献
7.
海滩养护已经成为全球基于自然（nature-based）海岸防护的主要手段，并得到广泛应用。随着全球强风区海岸海滩养护工程数量的增加，海滩养护对海岸风沙过程产生的一系列影响逐渐得到重视。海滩养护工程形成了新的海滩地貌形态，扩大了海滩风区、增加了风沙物源、提高了滩面高程、改变了滩面沉积物，海滩地貌和沉积物组分变化引起了风沙运动过程的变化，与自然海滩风沙过程相比，有其独特的过程和特征，已经成为海岸风沙研究的热点之一。本文从海滩养护影响下的风沙环境变化、风沙活动变化以及养护海滩对沙丘的影响等3个方面梳理了国内外研究进展，提出养护海滩风沙研究存在区域不平衡以及风沙过程的综合性影响和定量化研究不足等问题，并结合我国海滩养护未来的发展趋势，从强风区养护海滩风沙运动规律、养护海滩风沙环境全要素的综合影响和风沙作用变化的模型评估等方面展望了我国养护海滩风沙研究的未来发展方向。 相似文献
8.
Erosion of the southern Gold Coast beaches (SE Queensland, Australia) was exacerbated after the extension of the Tweed River training walls in the early 1960s. To achieve the objective of restoring and maintaining beach amenity, significant nourishment works have been undertaken in Coolangatta Bay over the past 30 years. Particularly, under the Tweed River Entrance Sand Bypassing Project (TRESBP) since 1995, a number of nourishment campaigns and the implementation of a permanent sand bypass system in 2001 have resulted in significant changes of Coolangatta Bay morphology. The present case study investigates the influence of both wave climate and nourishment works on the area extending from the updrift Snapper Rocks area to downdrift Kirra Beach. SWAN spectral wave model is implemented at Coolangatta Bay area and forced by the global wave model WW3 to estimate wave forcing and the potential natural longshore drift entering in Coolangatta. Specific transects extracted from accurate bathymetric surveys are used to investigate and quantify Coolangatta Bay sedimentation for the period 1987–2005. A network of Argus video stations provides high sample rate information on the shoreline evolution. Results show that, over the past 10 years, Coolangatta Bay has infilled rapidly. Sedimentation reached up to 6 m in some areas between 1995 and 2005, with beach width increasing by 200 m at Kirra Beach. Rapid seaward shoreline migration is consistent with the intense over-pumping of sand relative to the natural potential to move sand alongshore. The nourishment strategy used during this project has successfully delivered large amounts of sand to the southern Gold Coast embayment, although it has been up to now controversial from many community perspectives. The artificial sand bypassing process proved to be much more efficient than depositing the dredged sand in the nearshore area which requires a significant period of low energy condition in order for the deposited sediment to migrate shoreward and weld to the shore. This case study confirms that, when carefully undertaken, sand bypassing is a sustainable and flexible soft engineering approach which can work in concert with natural processes. 相似文献
9.
The empirical bay shape model proposed by Hsu and Evans in 1989 for predicting the static planform of a pocket beach is expanded to enable the calculation of three-dimensional beach changes on a pocket beach with a seawall. The original formulation was developed on the basis of a second-order regression analysis. Unlike the one-line model of shoreline changes, the model of Hsu and Evans does not require repeated calculations of the wave field and shoreline position, because it was derived on the assumption of null sediment movement within a pocket beach in static equilibrium, hence without the need of applying the continuity condition of total sand volume in the calculation. The expanded model proposed by the present authors satisfies the total sand budget on a pocket beach, by taking into account the concept of depth change due to longshore sand transport. Model tests were carried out and the new model was further applied to the beach changes at Kemigawa on the northeast of Tokyo Bay in Chiba Prefecture, as well as at Oarai in Ibaraki Prefecture, Japan. On both locations, seawall has been installed as countermeasures against beach erosion, where wave sheltering effect of the main breakwater and beach changes in front of the seawall has also been observed. With this expansion, the present model can be applied to predict the three-dimensional beach changes on a coast with seawall on a pocket beach. 相似文献
10.
A standard assumption in coastal engineering is that the porosity of natural beach sand (non-cohesive) is 40%. However, is this assumption correct for all beach sand? This paper proposes an accurate and simplified method to assess changes in sand porosity after beach nourishment by means of in-situ density surveys through a nuclear densimeter. This novel application has been applied to different beaches in the southwest of Spain according to the tidal range, grain size and beach morphology in several terms. General results show that sand porosities range from 25.6% to 43.4% after beach nourishment works. This research can be considered a support tool in coastal engineering to find shifting sand volumes as a result of sand porosity variability after beach nourishment and later marine influence. 相似文献
11.
为提高海水浴场的安全性,避免发生溺水事故,文章以潮汐汊道及其沙滩的动力地貌结构和发育演变为基础,研究青岛市灵山湾城市阳台海水浴场沙滩的安全风险和动力机制,并提出风险防范建议。研究结果表明:河口潮汐汊道落潮流三角洲的潮汐水道延伸至沙滩滩面,高潮时淹没,落急时水流集中,形成流向外海的高速水流,极易引发海水浴场安全事故;区域落潮流与汊道落潮流相叠加、落潮流三角洲阻挡沿岸输沙造成下游局部岸段侵蚀以及沿岸输沙变化导致水道迁移摆动等因素进一步加大潮汐汊道附近沙滩的安全风险;安全风险最大的地点位于沿岸输沙下游与区域落潮流流向一致的潮汐水道末端附近沙滩,且该位置不稳定,随波浪场发生年际和季节变化;在潮汐汊道沙滩岸段设置海水浴场前应研究其动力地貌和发育演变,划分危险区和安全区,浴场设置后定期监测并确定危险区的位置,并在沙滩安全维护和质量评价等方面将潮汐汊道作为重要判定指标。 相似文献
12.
美国东海岸海滩养护工程对中国砂质海滩旅游资源开发与保护的启示 总被引：5，自引：2，他引：5
借鉴美国长期以来东部海岸的海滩养护工程投入大量资金物力所取得的显著成效，提出了中国砂质海滩资源开发面临的问题，如海岸侵蚀造成砂质海滩资源丧失、砂质海滩旅游资源面临严重的污染、砂质海滩旅游资源的利用程度差异悬殊、砂质海滩旅游资源的人为破坏严重等，预见到中国实施海滩养护工程将是大势所趋，该工程将会被纳入国家或地方海岸综合规划管理与相关法律中。 相似文献
13.
In the light of global warming and sea level rise there are many coastal beaches that suffer from erosion. Beach nourishment has become a common practice to maintain the sediment balance on a shore-face. In this paper, a three-dimensional numerical model for evaluating long-term impact of beach nourishment projects has been developed. The model addresses the longstanding complex issue of coastal morphology and sediment grain size distribution from an unconventional angle, which exploits the strong links between grain size distribution and the prevailing transport direction of each sediment constituent under ‘average’ wave and storm action. The present model predicts the redistribution of nourished sediment according to the subtle clues implied by equilibrium distribution curves and latest coastal wave transformation theories. After verification against recent field observations in Terschelling, The Netherlands, the model was used to predict long-term effects of different beach nourishment strategies. It was found that: (a) given the source sediment available in Terschelling the tactics of large volume and less frequent implementation are better than otherwise; and (b) from a pure engineering point of view, waterline nourishment outperforms offshore trough nourishment.The model offers an additional tool for coastal engineers to evaluate the feasibility, effectiveness and the optimization of dumping locations for beach nourishment projects. It is also a useful tool for stratigraphic modelling of shallow-marine sedimentation in conjunction with sea level changes. 相似文献
14.
Charles W. Finkl 《Geo-Marine Letters》1981,1(2):155-161
Artificial beach nourishment, the placing of sand onto eroded beaches, is increasingly employed by coastal engineers as an
alternative to structural control of shoreline erosion. Man-made beaches approximating natural forms and processes offer greater
protection against storms than eroded beaches and provide increased recreational opportunities. It is hoped that maintenance
nourishment will keep pace with subsidence and eustatic rise in sea level, primary causes of beach erosion. Even though negative
impacts of beach restoration may be short-lived and limited in scope, sound ecological engineering practices require careful
monitoring of dredging operations. 相似文献
15.
海滩养护过程和工程技术 总被引：1，自引：0，他引：1
海滩养护是根据设计方案,向海滩大量抛沙,或者同时辅以硬工程,使受蚀海滩增宽和稳足的工程,是抵御海岸侵袭灾害的最佳措施。上世纪末发达国家已普遍开展,我国目前尚属起步,但近年发展迅速。该工程分调查,重建和修补3个阶段,三者相互补充和制约。重建前必须充分调查目标岸段,以为设计养护方案提供依据;重建阶段应注重抛沙位置、沙成分、抛沙量和沙源选择等工序;重建后应进行多年的剖面监测和再抛沙的修补。在那些浪大,沙少和岩礁裸露的侵蚀岸段,应辅以丁坝或岸外潜坝等硬工程加以抵浪,维持所填沙的稳定。 相似文献
16.
Immediate profile and planform evolution of a beach nourishment project with hurricane influences 总被引：1，自引：0，他引：1
In this study, planform adjustment began during a period of calm weather immediately after nourishment and then the passage of one strong storm caused a substantial portion of the total profile equilibration. Weekly beach profiles, shoreline surveys, and nearshore wave measurements were conducted before, during, and immediately after construction of the 1100-m long Upham Beach nourishment project on the low-energy, west coast of Florida. This project was constructed in three segments: the wide north segment, the central segment, and the narrow south segment. With the exception of the relatively distant passage of Hurricane Charley, calm weather prevailed for 45 days following completion of the south and central segments. Construction of the wide north segment was completed on August 27, 2004. Substantial planform diffusion occurred prior to construction completion via formation of a 300-m long spit extending from the wide north segment. The shoreline orientation was changed abruptly due to this diffusion spit formation, as opposed to the gradual adjustment predicted by most long-term models. Planform adjustment was initiated prior to profile equilibration, and it did not require high-energy conditions. A simple vector sum model for determining the orientation of a potential diffusion spit was developed. This study recommends designing end transitions at the predicted diffusion spit orientation to avoid post-nourishment spit formation during future projects. 相似文献
17.
Eco-environmental impact assessment of pre-leisure beach nourishment on the benthic invertebrate community at Anping coast 总被引：1，自引：0，他引：1
In recent years,owing to global warming and the rising sea levels,beach nourishment and groin building have been increasingly employed to protect coastal land from shoreline erosion.These actions may degrade beach habitats and reduce biomass and invertebrate density at sites where they were employed.We conducted an eco-environmental evaluation at the Anping artificial beach-nourishment project area.At this site,sand piles within a semi-enclosed spur groin have been enforced by use of eco-engineering concepts since 2003.Four sampling sites were monitored during the study period from July 2002 to September 2008.The environmental impact assessment and biological investigations that we conducted are presented here.The results from this study indicate that both biotic(number of species,number of individual organisms,and Shannon-Wiener diversity) and abiotic parameters(suspended solids,biological oxygen demand,chemical oxygen demand,dissolved inorganic nitrogen,dissolved inorganic phosphorus,total phosphorus,total organic carbon,median diameter,and water content) showed significant differences before and after beach engineering construction.Biological conditions became worse in the beginning stages of the engineering but improved after the restoration work completion.This study reveals that the composition of benthic invertebrates changed over the study period,and two groups of organisms,Bivalvia and Gastropoda,seemed to be particularly suitable to this habitat after the semi-enclosed artificial structures completion. 相似文献
18.
海阳市砂质海岸资源丰富,延绵近120 km,尤以万米沙滩浴场著称,但近年岸滩侵蚀严重影响其社会经济发展.本研究基于海阳市羊角畔两侧长约20 km典型砂质海岸连续3 a的海岸线蚀和典型剖面蚀淤调查,定量化研究海滩侵蚀及其变化,辅以一维数值模型,研究人类活动影响下的泥沙运动特征和海滩侵蚀机制.研究结果表明,调查区42.5％和5.90％的砂质海岸分别处于侵蚀和强侵蚀状态,羊角畔东侧海岸侵蚀强度高于西侧,海阳港至海阳核电厂之间海滩侵蚀强度最高,海滩侵蚀强度与人类活动扰动程度密切相关.海岸工程、临海养殖和人为采砂导致海阳市部分砂质海岸侵蚀严重的主要原因,导致羊角畔两侧海岸侵蚀机制也不同.基于各岸段侵蚀机制特征有针对性地提出退养还滩、凸堤拆除和沙滩喂养等对策,以减缓海阳砂质海岸侵蚀威胁. 相似文献
19.
20.
This paper summarizes the results of over 8 years of data describing the performance of a large beach nourishment project on Perdido Key, immediately adjacent to Pensacola Pass in Escambia County, FL, USA. As a result of a major excavation of the entrance channel to Pensacola Bay, over 7 million m3 of beach-quality sand were placed along the easternmost 7.5 km of Perdido Key, adjoining the entrance channel at Pensacola Pass. The project included the placement of 4.1 million m3 of sand directly upon the shoreline in 1989–1990, followed by the placement of an additional 3 million m3 as an underwater berm just offshore of the beach nourishment project in water depths of roughly 6 m. Monitoring of the performance of the beach nourishment project and the offshore berm has been conducted since 1989, beginning with a pre-construction survey of the project area. Monitoring surveys have been conducted on an annual or biennial basis since that time, with the most recent survey occurring in July/August, 1998. Over 8 years of monitoring data indicate that the beach nourishment project has retained approximately 56% of the original volume placed within the 7.5-km project length. In addition, according to the latest monitoring survey, the dry beach width of the project, initially constructed as 135 m on average, is still 53 m wider than pre-project conditions. Approximately 41% of the originally placed dry planform area remains as of July 1998. The most recent monitoring surveys in 1995, 1997, and 1998 encompass the effects of two major storm systems, Hurricanes Erin (August 1995) and Opal (October 1995). Monitoring of the offshore berm area indicates only a slight landward migration of the berm, accompanied by a minor decrease in volume, over the entire monitoring period. The performance of both the beach nourishment project and the offshore berm appear to be significantly related to the two storm events, particularly Hurricane Opal, and the proximity of the project to the tidal entrance at Pensacola Pass. Comparison of the documented performance of the beach nourishment project to simple existing analytical models of beach-fill evolution have yielded encouraging results in terms of preliminary design aids for future beach nourishment projects in the vicinity of deep tidal entrances. 相似文献