共查询到20条相似文献，搜索用时 15 毫秒
1.
Identifying storm impacts on an embayed, high-energy coastline: examples from western Ireland 总被引：1，自引：0，他引：1
J. A. G. Cooper D. W. T. Jackson F. Navas J. McKenna G. Malvarez 《Marine Geology》2004,210(1-4):261-280
Large sections of the western Irish coast are characterised by a highly compartmentalised series of headland-embayment cells in which sand and gravel beaches are backed by large vegetated dune systems. Exposure to modally high-energy swell renders most of these beaches dissipative in character. A mesotidal range (c. 3.5–4.5 m) exists along much of the coast. Analysis of instrumental wind records from three locations permitted the identification of a variety of storm types and the construction of storm catalogues. Few individual storms were recorded at all three stations indicating a lack of regional consistency in storm record. Of the total storms recorded, only a small percentage are potentially damaging (onshore directed) and even fewer span a high tide and thus potentially induce a measurable morphological response at the coast.
Through a combination of historical records, meteorological records, field observations and wave modelling we attempt to assess the impact of storms. Quantifiable records of coastal morphology (maps, air photos and beach profiles) are few in number and do not generally record responses that may be definitely attributed to specific storms. Numerical wave simulations and observations at a variety of sites on the west Irish coast, however, provide insights into instantaneous and medium term (decadal) storm responses in such systems.
We argue that beaches and dunes that are attuned to modally high-energy regimes require extreme storms to cause significant morphological impact. The varying orientation of beaches, a spatially nonuniform storm catalogue and the need for a storm to occur at high water to produce measurable change, impart site-specific storm susceptibility to these embayments. Furthermore, we argue that long-period wave energy attenuation across dissipative shorefaces and beaches reduces coastal response to distant storms whereas short-period, locally generated wind waves are more likely to cause major dune and beach erosion as they arrive at the shoreline unrefracted.
This apparently variable response of beach and dune systems to storm forcing at a decadal scale over a coastline length of 200 km urges caution in generalising regarding regional-scale coastal responses to climatic change. 相似文献
2.
基于 SWAN 波浪传播模型建立包含风暴潮与天文潮耦合传播的台风浪数值模型,通过多次台风引起的波浪模拟,证实该模型可适用于浙江沿海.将1949年以来登陆我国大陆沿海最强的“5612”号台风作为典型的超强台风,计算了超强台风在浙北至浙南3个不同地点登陆遭遇天文潮高潮位时产生的沿海波高过程.结果显示,在开敞海区,登陆点南侧附近及其以北沿海,台风登陆时过程最大有效波高与风暴高潮位基本同时出现,而在登陆点以南远区的沿海海域,最大有效波高出现在登陆前的一个高潮位附近;超强台风作用下浙江陆域沿海离岸近1 km 范围内有效波高可达4耀6 m.这些结论对海堤工程设计和防灾减灾具有重要意义. 相似文献
3.
A numerical study on the impact of tidal waves on the storm surge in the north of Liaodong Bay 总被引：1，自引：0，他引：1
KONG Xiangpeng 《海洋学报(英文版)》2014,33(1):35-41
A storm surge is an abnormal sharp rise or fall in the seawater level produced by the strong wind and low pressure field of an approaching storm system.A storm tide is a water level rise or fall caused by the combined effect of the storm surge and an astronomical tide.The storm surge depends on many factors,such as the tracks of typhoon movement,the intensity of typhoon,the topography of sea area,the amplitude of tidal wave,the period during which the storm surge couples with the tidal wave.When coupling with different parts of a tidal wave,the storm surges caused by a typhoon vary widely.The variation of the storm surges is studied.An once-in-a-century storm surge was caused by Typhoon 7203 at Huludao Port in the north of the Liaodong Bay from July 26th to 27th,1972.The maximum storm surge is about 1.90 m.The wind field and pressure field used in numerical simulations in the research were derived from the historical data of the Typhoon 7203 from July 23rd to 28th,1972.DHI Mike21 is used as the software tools.The whole Bohai Sea is defined as the computational domain.The numerical simulation models are forced with sea levels at water boundaries,that is the tide along the Bohai Straits from July 18th to 29th（2012）.The tide wave and the storm tides caused by the wind field and pressure field mentioned above are calculated in the numerical simulations.The coupling processes of storm surges and tidal waves are simulated in the following way.The first simulation start date and time are 00：00 July 18th,2012; the second simulation start date and time are 03：00 July 18th,2012.There is a three-hour lag between the start date and time of the simulation and that of the former one,the last simulation start date and time are 00：00 July 25th,2012.All the simulations have a same duration of 5 days,which is same as the time length of typhoon data.With the first day and the second day simulation output,which is affected by the initial field,being ignored,only the 3rd to 5th day simulation results are used to study the rules of the storm surges in the north of the Liaodong Bay.In total,57 cases are calculated and analyzed,including the coupling effects between the storm surge and a tidal wave during different tidal durations and on different tidal levels.Based on the results of the 57 numerical examples,the following conclusions are obtained：For the same location,the maximum storm surges are determined by the primary vibration（the storm tide keeps rising quickly） duration and tidal duration.If the primary vibration duration is a part of the flood tidal duration,the maximum storm surge is lower（1.01,1.05 and 1.37 m at the Huludao Port,the Daling Estuary and the Liaohe Estuary respectively）.If the primary vibration duration is a part of the ebb tidal duration,the maximum storm surge is higher（1.92,2.05 and 2.80 m at the Huludao Port,the Daling Estuary and the Liaohe Estuary respectively）.In the mean time,the sea level restrains the growth of storm surges.The hour of the highest storm tide has a margin of error of plus or minus 80 min,comparing the high water hour of the astronomical tide,in the north of the Liaodong Bay. 相似文献
4.
Donald L. Forbes George S. Parkes Gavin K. Manson Lorne A. Ketch 《Marine Geology》2004,210(1-4):169-204
Storms play a major role in shoreline recession on transgressive coasts. In the southern Gulf of St. Lawrence (GSL), southeastern Canada, long-term relative sea-level rise off the North Shore of Prince Edward Island has averaged 0.3 m/century over the past 6000 years (>0.2 m/century over 2000 years). This has driven long-term coastal retreat at mean rates >0.5 m/a but the variance and details of coastal profile response remain poorly understood. Despite extensive sandy shores, sediment supply is limited and sand is transferred landward into multidecadal to century-scale storage in coastal dunes, barrier washover deposits, and flood-tidal delta sinks. Charlottetown tide-gauge records show mean relative sea-level rise of 3.2 mm/a (0.32 m/century) since 1911. A further rise of 0.7±0.4 m is projected over the next 100 years. When differenced from tidal predictions, the water-level data provide a 90-year record of storm-surge occurrence. Combined with wind, wave hindcast, and sea-ice data, this provides a catalogue of potentially significant coastal storms. We also document coastal impacts from three recent storms of great severity in January and October 2000 and November 2001. Digital photogrammetry (1935–1990) and shore-zone surveys (1989–2001) show large spatial and temporal variance in coastal recession rates, weakly correlated with the storm record, in part because of wave suppression or coastal protection by sea ice. Large storms cause rapid erosion from which recovery depends in part on local sand supply, but barrier volume may be conserved by washover deposition. Barrier shores with dunes show high longshore and interdecadal variance, with extensive multidecadal healing of former inlet and overwash gaps. This reflects recovery from an episode of widespread overwash prior to 1935, possibly initiated by intense storms or groups of storms in the latter half of the 19th century. With evidence from the storms of 2000–2001, this points to the importance of storm clustering on scales of weeks to years in determining erosion vulnerability, as well as the need for a long-term, large-scale perspective in assessing coastal stability. The expected acceleration in relative sea-level rise, together with projections of increasing storm intensity and greatly diminished winter ice cover in the southern GSL, implies a significant increase in coastal erosion hazards in future. 相似文献
5.
绿色海堤是传统结构工程与海岸生态系统共同组合而成的新型海堤, 用以应对未来海面上升、风暴加剧给低地海岸防护带来的挑战。需解决的问题主要有海岸生态系统消浪过程及生态系统在海堤体系中的配置方式。理论分析、现场观测、物模数模所获结果表明, 海岸生态系统确有显著的消浪功能: 1) 陆架泥区消浪, 其机制以再悬浮和浮泥运动为主, 底部摩擦为次; 2) 潮滩下部的粉砂细砂滩底部摩擦和推移质运动共同造成波能耗散, 而上部的泥滩则以再悬浮和悬沙输运为主; 3) 在盐沼、红树林、海草床等由植被构成的生态系统, 植物通过形态阻力、茎秆运动来阻滞水流、耗散波能, 其效能高于沉积物床面对波能的耗散; 4) 生物礁主要有珊瑚礁和牡蛎礁, 其消能作用主要通过床面摩擦和波浪破碎, 效能较高, 尤其是在风暴期间。生态系统如何成为海堤的有机组成部分, 尤其是侵蚀型海岸的生态位修复和绿色海堤整体设计, 还需进一步研究相关的科学问题: 与硬质工程结合的盐沼-牡蛎礁的适应性生物学; 未来环境变化条件下生态系统的稳定性; 绿色海堤生态系统空间配置及其与风暴事件的时间尺度匹配; 基于均衡剖面理论的海堤形态优化。 相似文献
6.
Tariq Masood Ali Khan D. A. Razzaq Qamar-Uz-Zaman Chaudhry Dewan Abdul Quadir Anwarul Kabir Majajul Alam Sarker 《Marine Geodesy》2002,25(1):159-174
The UNEP in its regional seas program in 1989 has included Pakistan in a group of countries which are vulnerable to the impact of rising sea level. If the present trend of sea level rise (SLR) at Karachi continues, in the next 50 years the sea level rise along the Pakistan Coast will be 50 mm (5 cm). Since the rising rates of sea level at Karachi are within the global range of 1-2 mm/year, the trends may be treated as eustatic SLR. Historical air temperature and sea surface temperature (SST) data of Karachi also show an increasing pattern and an increasing trend of about 0.67°C has been registered in the air temperature over the last 35 years, whereas the mean SST in the coastal waters of Karachi has also registered an increasing trend of about 0.3°C in a decade. Sindh coastal zone is more vulnerable to sea level rise than Baluchistan coast, as uplifting of the coast by about 1-2 mm/year due to subduction of Indian Ocean plate is a characteristic of Baluchistan coast. Within the Indus deltaic creek system, the area nearby Karachi is more vulnerable to coastal erosion and accretion than the other deltaic region, mainly due to human activities together with natural phenomena such as wave action, strong tidal currents, and rise in sea level. Therefore, The present article deals mainly with the study of dynamical processes such as erosion and accretion associated with sea level variations along the Karachi coast and surrounding Indus deltaic coastline. The probable beach erosion in a decade along the sandy beaches of Karachi has been estimated. The estimates show that 1.1 mm/year rise in sea level causes a horizontal beach loss of 110 mm per year. Therefore, coast eroded with rise in sea level at Karachi and surrounding sandy beaches would be 1.1 m during a period of next 10 years. The northwestern part of Indus delta, especially the Gizri and Phitti creeks and surrounding islands, are most unstable. Historical satellite images are used to analyze the complex pattern of sediment movements, the change in shape of coastline, and associated erosion and accretion patterns in Bundal and Buddo Islands. The significant changes in land erosion and accretion areas at Bundal and Buddo Islands are evident and appear prominently in the images. A very high rate of accretion of sediments in the northwestern part of Buddo Island has been noticed. In the southwest monsoon season the wave breaking direction in both these islands is such that the movement of littoral drift is towards west. Erosion is also taking place in the northeastern and southern part of Bundal Island. The erosion in the south is probably due to strong wave activities and in the northeast is due to strong tidal currents and seawater intrusion. Accretion takes place at the northwest and western parts of Bundal Island. By using the slope of Indus delta, sea encroachment and the land area inundation with rising sea level of 1 m and 2 m have also been estimated. 相似文献
7.
Tariq Masood Ali Khan D. A. Razzaq Qamar-Uz-Zaman Chaudhry Dewan Abdul Quadir Anwarul Kabir Majajul Alam Sarker 《Marine Geodesy》2013,36(1-2):159-174
The UNEP in its regional seas program in 1989 has included Pakistan in a group of countries which are vulnerable to the impact of rising sea level. If the present trend of sea level rise (SLR) at Karachi continues, in the next 50 years the sea level rise along the Pakistan Coast will be 50 mm (5 cm). Since the rising rates of sea level at Karachi are within the global range of 1-2 mm/year, the trends may be treated as eustatic SLR. Historical air temperature and sea surface temperature (SST) data of Karachi also show an increasing pattern and an increasing trend of about 0.67°C has been registered in the air temperature over the last 35 years, whereas the mean SST in the coastal waters of Karachi has also registered an increasing trend of about 0.3°C in a decade. Sindh coastal zone is more vulnerable to sea level rise than Baluchistan coast, as uplifting of the coast by about 1-2 mm/year due to subduction of Indian Ocean plate is a characteristic of Baluchistan coast. Within the Indus deltaic creek system, the area nearby Karachi is more vulnerable to coastal erosion and accretion than the other deltaic region, mainly due to human activities together with natural phenomena such as wave action, strong tidal currents, and rise in sea level. Therefore, The present article deals mainly with the study of dynamical processes such as erosion and accretion associated with sea level variations along the Karachi coast and surrounding Indus deltaic coastline. The probable beach erosion in a decade along the sandy beaches of Karachi has been estimated. The estimates show that 1.1 mm/year rise in sea level causes a horizontal beach loss of 110 mm per year. Therefore, coast eroded with rise in sea level at Karachi and surrounding sandy beaches would be 1.1 m during a period of next 10 years. The northwestern part of Indus delta, especially the Gizri and Phitti creeks and surrounding islands, are most unstable. Historical satellite images are used to analyze the complex pattern of sediment movements, the change in shape of coastline, and associated erosion and accretion patterns in Bundal and Buddo Islands. The significant changes in land erosion and accretion areas at Bundal and Buddo Islands are evident and appear prominently in the images. A very high rate of accretion of sediments in the northwestern part of Buddo Island has been noticed. In the southwest monsoon season the wave breaking direction in both these islands is such that the movement of littoral drift is towards west. Erosion is also taking place in the northeastern and southern part of Bundal Island. The erosion in the south is probably due to strong wave activities and in the northeast is due to strong tidal currents and seawater intrusion. Accretion takes place at the northwest and western parts of Bundal Island. By using the slope of Indus delta, sea encroachment and the land area inundation with rising sea level of 1 m and 2 m have also been estimated. 相似文献
8.
基于SWAN波浪传播模型建立包含风暴潮与天文潮耦合传播的台风浪数值模型,将1949年以来登陆我国大陆沿海最强的5612#台风作为典型的超强台风,计算了超强台风沿中线和北线路径登陆遭遇天文潮高潮位时产生的沿海波高过程。结果显示:河口波高总体分布下游大于上游,北岸大于南岸,两岸代表断面堤前最大有效波高可达5.5 m;中线路径生成的近岸台风浪波高为单峰过程,北线路径时北岸的波高出现双峰过程,波高峰值与风暴高潮位并非总是同步出现,两者时间差最大为4 h;根据频率曲线分析,中线、北线路径超强台风作用下乍浦站台风浪的重现期分别为135 a和350 a;中潮时的近岸台风浪波高比大潮降低0.1~0.2 m,小潮时再比中潮降低同样幅度。这些结论对海堤工程设计和防灾减灾具有重要意义。 相似文献
9.
The Nampo dike, which is located at the west coast of Korea, was destroyed by wave overtopping during the storms on 30 August and 17 September in 1959. In this paper, is performed the probabilistic assessment of wave overtopping of Nampo dike by use of Owen model, Van der Meer ＆ Janssen model and Hedges ＆ Reis model for wave overtopping of seawall. Based on the available tidal and wave data for storm surges in 1989, the risk assessment of wave overtopping of the Nampo dike has been carried out by both Level Ⅱ and Level Ⅲ reliability methods. The calculated resuhs show the general agreement of failure probability between the two methods. By utilizing the rehabilitated cross section of Nampo dike, the failure probability of wave overtopping for the Nampo dike after rehabilitation will be rapidly reduced to that of initial design at crest level of 9.0 m with the improved slope from 1 ： 2 to 1 ： 4 at seaside. Since the sea level may only rise 1.0 m in the next few decades, the failure probability of Nampo dike will be still in the safe range. 相似文献
10.
粉沙质海岸离岸围垦后港内淤积引人关注。基于平面二维潮流数学模型,采用网格嵌套技术,模拟了渤海、曹妃甸海域潮流场;该海域泥沙为粘性沙,且围垦后港内流速很小,采用悬沙运动数学模型模拟了潮流和波浪作用下正常天气和大风天的含沙量场,分析了大风后含沙量衰减过程,计算了正常天气年淤积强度和大风天泥沙淤积厚度。计算表明,外海泥沙主要通过甸头东侧老龙沟进入港池水域。正常天气下,港内流速小,基本处于淤积环境,但由于外海含沙量小,港池水域年淤积厚度小于10 cm。大风浪作用下,曹妃甸海域含沙量明显增大,由老龙沟进入三港池的泥沙沿程落淤,港内普遍淤积,泥沙淤积厚度在5 cm以内。 相似文献
11.
Ａｍｏｄｅｌｏｆｐｒｏｆｉｌｅｅｖｏｌｕｔｉｏｎｏｎｗａｖｅ－ｄｏｍｉｎａｔｅｄｍｕｄｃｏａｓｔＺｈａｎｇＹｏｎｇ，ＹｕＺｈｉｙｉｎｇａｎｄＪｉｎＬｉｕ（ＲｅｃｅｉｖｅｄＪｕｌｙ２３，１９９６；ａｃｃｅｐｔｅｄＯｃｔｏｂｅｒ．．８，１９９６）Ａｂｓｔ... 相似文献
12.
厦门岛海滩剖面对9914号台风大浪波动力的快速响应 总被引：17，自引：1，他引：17
根据 9914号台风发生前后对厦门岛滨岸海滩剖面地形的重复测量结果及有关台风要素和潮位的实测资料 ,探讨了台风袭击厦门岛期间海滩的变形特征和侵蚀状态。分析得出 ,海滩地形受台风暴浪冲击普遍发生急剧变化。横向冲淤变形以东岸海滩为最剧烈 :滩肩蚀退可达 2 5m ;滩面呈上冲下淤 ,上段和滩肩的单宽冲蚀量达 30m3 /m ;下段单宽淤积量达 17m3 /m ;剖面类型由滩肩式断面向沙坝式断面转变。这种变形特点是在台风大浪波动力和潮位暴涨的双重作用下造成的。台风期间 ,沿岸输沙能力以北岸最高 ,南岸次之 ,东岸较低 ;且自南岸到东岸 ,随着沿岸输沙量减少 ,横向变形相应有增大的趋势。这是9914号台风以偏东方向袭击厦门的结果。表明不同方向海岸岸滩地形对同一台风大浪波动力作用具有不同响应特征。 相似文献
13.
14.
The morphology, bedforms and hydrodynamics of Merlimont beach, in northern France, characterised by intertidal bars and a spring tidal range of 8.3 m, were surveyed over a 10-day experiment with variable wave conditions that included a 2-day storm with significant wave heights of up to 2.8 m. The beach exhibited two pronounced bar-trough systems located between the mean sea level and low neap tide level. Waves showed a cross-shore depth modulation, attaining maximum heights at high tide. The mean current was characterised dominantly by strong tide-induced longshore flows significantly reinforced by wind forcing during the storm, and by weaker, dominantly offshore, wave-induced flows. Vertical tidal water-level variations (tidal excursion rates) showed a bimodal distribution with a peak towards the mid-tide position and low rates near low and high water. The two bar-trough systems in the mid-tide zone remained stable in position during the experiment but showed significant local change. The absence of bar migration in spite of the relatively energetic context of this beach reflects high macro-scale bar morphological lag due to a combination of the large vertical tidal excursion rates in the mid-tide zone, the cross-shore wave structure, and the pronounced dual bar-trough system. The profile exhibited a highly variable pattern of local morphological change that showed poor correlation with wave energy levels and tidal excursion rates. Profile change reflected marked local morphodynamic feedback effects due mainly to breaks in slope associated with the bar-trough topography and with trough activity. Change was as important during low wave-energy conditions as during the storm. Strong flows in the entrenched troughs hindered cross-shore bar mobility while inducing longshore migration of medium-sized bedforms that contributed in generating short-term profile change. The large size and location of the two pronounced bars in the mid-tide zone of the beach are tentatively attributed respectively to the relatively high wave-energy levels affecting Merlimont beach, and to the cross-shore increase in wave height hinged on tidal modulation of water depths. These two large quasi-permanent bars probably originated as essentially breakpoint bars and are different from a small bar formed by swash and surf processes in the course of the experiment at the mean high water neap tide level, which is characterised by a certain degree of tidal stationarity and larger high-tide waves. 相似文献
15.
The Longard Tube experimental revetment installed in Del Mar, California in December 1980 has been monitored and its performance documented until it subsided and became ineffective during the severe winter storms of December 1982 to March 1983. The data suggest that the tube had no measurable effect on the sand level at Del Mar beach. The beach profile monitoring program conducted by Scripps in Del Mar since 1974 served as important background information for the design and interpretation of the monitoring program measurements.The tube experienced relatively minor storm wave interaction during winter 1980–1981. This was followed by heavy beach accretion on the entire reach in spring 1981 and an unusually mild winter of 1981–1982. By July 1982 the tube was totally buried behind a berm extending 35 m seaward. The severe winter storm waves of 1982–1983 coupled with high sea level due to high spring astronomical tides, sustained onshore westerly winds and low atmospheric pressure, eroded the sand level on Del Mar beach to the lowest level in at least 10 years. The Longard Tube settled differentially by up to 2 m and was continually overtopped at high tide, rendering it ineffective by late January 1983. It was removed in March 1983. The principal conclusion of the study is that the Longard Tube configured as it was in the Del Mar test is not a substantial enough barrier to effectively prevent beach sand erosion during severe storm events on the Southern California coast. 相似文献
16.
17.
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。 相似文献
18.
通过对采集于江苏省盐城市上冈镇的三个柱状沉积剖面(W,M,E)的岩性特征及其对比关系的分析、沉积物14C年代的测定以及沉积物样品的粒度、磁化率特征的分析,结合有孔虫和颗石藻的分析结果,判定研究沉积层段为全新世中期的潮滩沉积.孢粉分析结果显示当时的气候较现在温暖.以潮汐层理的周期性特征为依据,对以泥为主的潮滩沉积剖面中每隔10~20cm有规律出现的一层砂作了分析,结果表明这一沉积特征为季节性的潮滩沉积旋回.在此基础上,观察沉积剖面中的风暴潮事件的记录状况,估算出剖面中记录的与9711号台风风暴潮强度相当的风暴潮的发生频率为二至四年一遇,而依据盐城市东台梁垛河闸多年的现代最高潮位资料,应用耿贝尔(Gum-bel)曲线拟合法计算出的9711号台风所引起的风暴潮频率为十二年一遇,即全新世中期温暖期的台风风暴潮的频率比现在大.据此推测全球变暖后台风风暴潮的频率将会增加. 相似文献
19.
On average, five to six storms occur in the Qiongzhou Strait every year, causing significant damage to coastal geomorphology and several property losses. Tropical Storm Bebinca is the most unusual and complex storm event that has occurred in this region over the last 10 years. To detect the high-frequency beachface responses to the storm, a pressure sensor was deployed in the surf zone to record the free sea surface height, and the heights of grid pile points on the beachface were measured manua... 相似文献
20.
江苏中部淤泥质海岸岸线变化遥感监测研究 总被引：4，自引：0，他引：4
海岸线监测是了解海岸冲淤变化的基础。针对淤泥质海岸潮间带坡度平缓的特点,考虑到潮汐对遥感海岸线监测的影响,基于多潮位站插值校正的水边线离散点潮位赋值及坡度计算对水边线方法进行了改进,并结合潮间带实测坡度资料校正,推算遥感海岸线。选择江苏中部冲淤变化频繁、自然岸线保有率较高的扁担河口至川东港岸段开展海岸线变迁遥感监测研究。结果表明,研究区坡度主要在0.001~0.002之间,潮间带宽度由北向南越来越宽。北部扁担河口至射阳河口岸段处于冲刷环境中,大量以养殖塘围堤为主的人工岸线不断被侵蚀后退;射阳河口至四卯酉河口岸段以海岸线在自然状态下的动态变化为主,2010-2015年平均冲淤速率小于10 m/a,变化幅度较小;南部四卯酉河口至川东港岸段,自然岸线淤长明显,同时人工围垦导致岸线不断向海推进。根据监测结果,认为新洋港至斗龙港岸段应为研究区由北部侵蚀转向南部淤长的过渡带。 相似文献