Monitoring of the sediment dynamics along a sandy shoreline by means of airborne hyperspectral remote sensing and LIDAR: a case study in Belgium     

B. Deronde  R. Houthuys  J.‐P. Henriet  V. Van Lancker 《地球表面变化过程与地形》2008,33(2):280-294

Airborne hyperspectral data and airborne laserscan or LIDAR data were applied to analyse the sediment transport and the beach morphodynamics along the Belgian shoreline. Between 2000 and 2004, four airborne acquisitions were performed with both types of sensor. The hyperspectral data were classified into seven sand type classes following a supervised classification approach, in which feature selection served to reduce the number of bands in the hyperspectral data. The seven classes allowed us to analyse the spatial dynamics of specific sediment volumes. The technique made it possible to distinguish the sand used for berm replenishment works or for beach nourishments from the sand naturally found on the backshore and the foreshore. Subtracting sequential DTMs (digital terrain models) resulted in height difference maps indicating the erosion and accretion zones. The combination of both data types, hyperspectral data and LIDAR data, provides a powerful tool, suited to analyse the dynamics of sandy shorelines. The technique was demonstrated on three sites along the Belgian shoreline: Koksijde, located on the West Coast and characterized by wide accretional beaches, influenced by dry berm replenishment works and the construction of groins; Zeebrugge, on the Middle Coast, where a beach nourishment was executed one year before the acquisitions started and where the dams of the harbour of Zeebrugge are responsible for the formation of a large accretional beach, and Knokke‐Heist, located on the East Coast and characterized by narrow, locally reflective, beaches, heavily influenced by nourishment activities. The methodology applied allowed retrieval of the main sediment transport directions as well as the amount of sediment transported. It proved to be specifically suited to follow up the redistribution and the re‐sorting of the fill in beach nourishment areas. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

基于RS技术的北江下游河道岸滩演变分析   总被引：1，自引：0，他引：1  

刘万侠  钟凯文  刘凯 《热带地理》2006,26(2):123-128

以1975～2001年共7个时相的遥感影像作为数据源,在GIS支持下采用动态分析方法,对比各个时期北江下游河道岸滩形态及位置变化,结合河道的地质、地貌、水文泥沙、整治工程等信息,分析洲滩消长的原因,获取河道横向演变特性,预测岸滩变化趋势以及整治工程效果.对比该时段内北江下游河道纵向演变情况,得出河道的纵向变形影响横向变形,总体变化两者成反比关系,河势向着稳定的趋势发展.  相似文献   

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     

蔡锋  苏贤泽  陈峰  陈坚 《台湾海峡》2000,19(3)

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。  相似文献   

复经验正交函数方法对湛江南三岛海滩剖面季节变化动态特征研究     

李志强  刘长华  杜健航  吴光林  张会领 《海洋工程》2012,30(2):79-86

利用复经验正交函数(CEOF)分析方法对湛江南三岛2009年2月22日至2010年4月21日期间的实测海滩剖面数据进行了分析。结果表明该海滩的季节变化有3个主要模态:第1模态是海滩风暴剖面和涌浪剖面之间的相互转换,其贡献占总方差的71.18%。其原因是海区侵蚀性风暴大浪和建设性涌浪的交替变化。第2模态是平均高、低潮线之间的地形变化,其原因是由于潮汐变化导致入射波浪冲流活动范围变化,占总方差的14.28%。第3模态是侵蚀大浪过后的水下沙坝向岸迁移,并受潮汐影响在滩面上摆动,占总方差的6.80%。最后指出必须重视风暴对华南海滩演变季节性过程的影响。  相似文献   

山东东营凹陷南坡地区沙四段纯下亚段湖相碳酸盐岩滩坝发育的控制因素探讨^*   总被引：2，自引：0，他引：2       下载免费PDF全文

宋国奇  王延章  路达  闫瑞萍  杨静 《古地理学报》2012,14(5):565-570

碳酸盐岩滩坝是断陷湖盆中一种重要的沉积类型。文章通过对古气候、古地貌、古物源、古水深和古盐度等因素对碳酸盐岩滩坝形成与分布控制作用进行研究,总结出了“古气候是基础,古地貌和古物源是条件,古水深是关键,古盐度是保障”是东营凹陷南坡地区沙河街组四段纯下亚段碳酸盐岩滩坝的“五古”控制模式。较干旱的温热适中的古气候条件下蒸发作用较强,有利于湖相碳酸盐岩的形成;水下隆起及其斜坡是碳酸盐岩滩坝沉积的有利场所,较低的碎屑岩物源供给指数为碳酸盐岩的发育提供了良好的环境;3～32m左右的古水深是碳酸盐岩发育的主要深度;古盐度为碳酸盐岩的沉积提供了物质保障,在一定程度上控制了白云岩和石灰岩的分布。采用主因素分析法对碳酸盐岩的控制因素进行了排序,古地貌对碳酸盐岩发育的控制作用最大,其次为古物源和古水深,古盐度的控制作用最小。  相似文献   

Links between wave forcing,offshore islands and a macro‐tidal headland‐bound bay beach          下载免费PDF全文

Tony Thomas  Michael R. Phillips  Allan T. Williams  Rhian E. Jenkins 《地球表面变化过程与地形》2014,39(2):143-155

Profiles were analysed in conjunction with wave climate to assess offshore island influences on an embayed beach at Tenby, Wales. Time series analyses showed medium and short‐term beach oscillation, with volume exchanges between zones lagging by up to six months. Dominant southerly and southwesterly waves caused sub and low tidal longshore drift from south towards north, while less frequent southeasterly waves generated counter drift. Modelled inshore breaking waves had less energy than offshore ones and the former behaved differently between the low and high tidal zones (spring tidal range of 7 · 5 m). Variations in wave direction from directly behind the islands resulted in reduced wave heights and statistical analyses agreed with wave model results. These were correlated to morphological change and it was concluded that offshore islands change wave dynamics and modify the morphology of embayed beaches in their lee. Consequently, this work provides significant new insights into offshore island influences, shoreline behaviour and especially tidal setting Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

波浪海滩沙丘相互作用模式研究述评   总被引：4，自引：2，他引：2  

董玉祥 《中国沙漠》2010,30(4):796-800

波浪-海滩-沙丘相互作用模式是对海岸沙丘形成与演化机理的宏观解析,是了解和认识海岸沙丘形态、类型与规模等的区域差异的基本途径,与海岸沙丘表面风沙流过程研究一样是研究海岸风沙问题不可或缺的重要方面。在对20世纪80年代以来国内外关于波浪-海滩-沙丘间相互作用模式研究历程回顾的基础上,重点总结和概述了国外所提出的波浪-海滩-沙丘间相互作用模式,包括小尺度的波浪-海滩-沙丘相互作用模式、中尺度的波浪-海滩-沙丘相互作用模式等,并展望了未来我国波浪-海滩-沙丘相互作用模式研究的基本方向与主要内容。  相似文献   

Field measurements of intertidal bar evolution on a high‐energy beach system          下载免费PDF全文

Derek W. T. Jackson  J. Andrew G. Cooper  Marianne O'Connor  Emilia Guisado‐Pintado  Carlos Loureiro  Giorgio Anfuso 《地球表面变化过程与地形》2016,41(8):1107-1114

Nearshore bars play a pivotal role in coastal behaviour, helping to protect and restore beach systems particularly in post‐storm conditions. Examination of bar behaviour under various forcing conditions is important to help understand the short‐ to medium‐term evolution of sandy beach systems. This study carried out over a nine‐week period examines, the behaviour of three intertidal bars along a high energy sandy beach system in northwest Ireland using high‐frequency topographic surveys and detailed nearshore hydrodynamic modelling. Results show that, in general, there was onshore migration for all the bars during the study period, despite the variability observed between bars, which was driven mostly by wave dominated processes. Under the prevailing conditions migration rates of up to 1.83 m day^?1 and as low as 0.07 m day^?1 were observed. During higher wave energy events the migration rates of the bars decelerated in their onshore route, however, under lower wave energy conditions, they quickly accelerated maintaining their shoreward migration direction. Tidal influence appears to be subordinate in these conditions, being restricted to moderating the localized wave energy at low tides and in maintaining runnel configurations providing accommodation space for advancing slip faces. The study highlights the intricate behavioural patterns of intertidal bar behaviour along a high energy sandy coastline and provides new insights into the relative importance of wave and tidal forcing on bar behaviour over a relatively short time period. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

美国海滩养护与海滩经济对中国 滨海旅游产业发展的启示     

任航  杨钿  张振克  蒋大亮  任则沛  谢丽 《热带地理》2016,36(2):253-259

根据美国最新的海滩经济和旅游研究的数据资料,分析了其海滩养护的概况、管理、对滨海旅游经济增长的贡献和当前面临的困境,对照分析了中国滨海旅游产业发展所面临的海岸侵蚀加剧、海滩环境污染、海滩养护投入力度不够、政府职能分散、旅游开发破坏公众利益等一系列问题,借鉴美国海滩旅游开发经验并结合中国实际情况,分别从海滩养护、海滩开发研究与评估、政府管理、动态监测几个层面提出中国未来海滩旅游开发的建议。  相似文献   

Backshore coarsening processes triggered by wave‐induced sand transport: the critical role of storm events     

Keiko Udo  Akira Mano 《地球表面变化过程与地形》2010,35(11):1269-1280

Spatial backshore processes were investigated through field observations of topography and median sand grain size at a sandy beach facing the Pacific Ocean in Japan. A comparison of the backshore profile and cross‐shore distribution of the median sand grain size in 1999 and 2004 revealed an unusual sedimentary process in which sand was coarsened in a depositional area in the 5‐year period, although sediment is generally coarsened in erosional areas. In support of these observations, monthly spatial field analyses carried out in 2004 demonstrated a remarkable backshore coarsening process triggered by sedimentation in the seaward part of the backshore during a storm event. In order to elucidate mechanisms involved in the backshore coarsening process, thresholds of movable sand grain size under wave and wind actions (a uniform parameter for both these cases) in the onshore and offshore directions were estimated using wave, tide, and wind data. The cross‐shore distributions of the estimated thresholds provided reasonable values and demonstrated a coarsening mechanism involving the intermediate zone around the shoreline under alternating wave and wind actions as a result of which coarse sand was transported toward the seaward part of the backshore by large waves during storms and then toward the landward part by strong onshore winds. The 5‐year backshore coarsening is most certainly explained by repetition of short‐term coarsening mechanisms caused by wave‐induced sand transport occurring from the nearshore to the intermediate zone. Copyright © 2010 John Wiley & Sons, Ltd  相似文献