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1.
The study area is 56-km coastal zone of Chennai district of the Tamil Nadu state, southeast coast of India. The coastline, which includes tourist resorts, ports, hotels, fishing villages, and towns, has experienced threats from many disasters such as storms, cyclones, floods, tsunami, and erosion. This was one of the worst affected area during 2004 Indian Ocean tsunami and during 2008 Nisha cyclone. The present study aims to develop a Coastal Vulnerability Index for the Chennai coast using eight relative risk variables to know the high and low vulnerable areas, areas of inundation due to future SLR, and land loss due to coastal erosion. Both conventional and remotely sensed data were used and analyzed with the aid of the remote sensing and geographic information system tools. Zones of vulnerability to coastal natural hazards of different magnitude (high, medium, and low) are identified and shown on a map. Coastal regional elevation, near-shore bathymetry, and socio-economic conditions have been considered as additional important variables. This study revealed that 11.01?km of the coastline has low vulnerability, 16.66?km has medium vulnerability, and 27.79?km is highly vulnerable in the study area, showing the majority of coastline is prone to erosion. The map prepared for the Chennai coast can be used by the state and district administration involved in the disaster mitigation and management plan and also as a tool in planning a new facility and for insurance purpose. 相似文献
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Assessment of the sensitivity of the southern coast of the Gulf of Corinth (Peloponnese, Greece) to sea-level rise 总被引：1，自引：0，他引：1
Efthimios Karymbalis Christos Chalkias George Chalkias Eleni Grigoropoulou George Manthos Maria Ferentinou 《Central European Journal of Geosciences》2012,4(4):561-577
The eustatic sea-level rise due to global warming is predicted to reach approximately 18?C59 cm by the year 2100, which necessitates the identification and protection of sensitive sections of coastline. In this study, the classification of the southern coast of the Gulf of Corinth according to the sensitivity to the anticipated future sealevel rise is attempted by applying the Coastal Sensitivity Index (CSI), with variable ranges specifically modified for the coastal environment of Greece, utilizing GIS technology. The studied coastline has a length of 148 km and is oriented along the WNW-ESE direction. CSI calculation involves the relation of the following physical variables, associated with the sensitivity to long-term sea-level rise, in a quantifiable manner: geomorphology, coastal slope, relative sea-level rise rate, shoreline erosion or accretion rate, mean tidal range and mean wave height. For each variable, a relative risk value is assigned according to the potential magnitude of its contribution to physical changes on the coast as the sea-level rises. Every section of the coastline is assigned a risk ranking based on each variable, and the CSI is calculated as the square root of the product of the ranked variables divided by the total number of variables. Subsequently, a CSI map is produced for the studied coastline. This map showed that an extensive length of the coast (57.0 km, corresponding to 38.7% of the entire coastline) is characterized as highly and very highly sensitive primarily due to the low topography, the presence of erosionsusceptible geological formations and landforms and fast relative sea-level rise rates. Areas of high and very high CSI values host socio-economically important land uses and activities. 相似文献
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The study area (the Gulf of Bejaia) is a coastal zone of about 70 km long in the eastern-central part of the Algerian coast. The coastline characterized by sandy beaches, hotels and tourist facilities, airport, port, villages and towns has known during these last decades several threats like storms, floods and erosion. The present work concerns the mapping of the physical and socioeconomic vulnerability of the Gulf Coast of Bejaia to sea level rise, using Coastal Vulnerability Index (CVI) and geospatial tools. The Physical CVI (CVIPhys) is calculated from seven physical variables: geomorphology, coastal slope, coastal regional elevation, sea level rise rate, shoreline erosion/accretion rates, tidal range and significant wave height. On the other hand, the parameters population, cultural heritage, roads, railways, land use and conservation designation constitute, for their part, the socioeconomic CVI (CVIeco). The values obtained from the calculation of CVIPhys vary between 3.53 and 81.83. These results revealed that 22.42 km of the studied coastline has a low physical vulnerability, 21.68 km a high vulnerability and 15.83 km a very high vulnerability, indicating that the most part of the coastline (53.59%) is vulnerable to sea level rise. According to the obtained values of CVIeco, the most vulnerable areas of high and very high risk represent 31.81 km of the total coastline. They were found along the western (Bejaia and Tichy) and eastern (Aokas, Souk El Tenine and Melbou) coast, while the least vulnerable stretches, covering 38.19 km of the total length of the coast, occupy the rest of the area. This study highlighted areas that will be most affected by future sea level rise (SLR) and storm events. It revealed that several development projects of Bejaia Gulf Coast, including tourist expansion areas, are planned in sites identified as very vulnerable. The results obtained from this assessment could guide local planners and decision-makers in developing coastal management plans in the most vulnerable areas. 相似文献
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Stratigraphic reconstruction of the Strzelecki Group outcrops in west Gippsland: new data on the present-day thickness and amount of erosion 总被引：1，自引：0，他引：1
The Lower Cretaceous Strzelecki Group forms the basement to the eastern part of the Gippsland Basin, but is exposed in the west and forms spectacular outcrops, especially along the coastal area between San Remo and Inverloch. The coastal area is highly faulted and lacks stratigraphic markers so matching sections in different fault blocks based only on lithology has not been possible. A combination of mapping, detailed logging, vitrinite reflectance measurements and palynology were used to determine the present-day thickness of the coastal sections and the amount of erosion that occurred during the Late Cretaceous. A total thickness of about 1500 m is inferred between Harmers Haven and Inverloch but because of the amount of faulting and probable repeated sections, the true thickness of Strzelecki Group exposed in the coastal outcrops is only about 300 m. Based on palynology and vitrinite reflectance results, the reconstructed Strzelecki Group stratigraphy has been subdivided into three distinct ‘bio-blocks’, with an eroded section estimated to range from 1.5 km (0.3–2.6 km at ±95% confidence limits) to 2.7 km (2.2–3.1 km at ±95% confidence limits). 相似文献
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Sea erosion is a serious threat to life and property in coastal towns. The coastline of Ada Foah has been facing sea erosion and occasional flooding for several decades. This research investigated the socio-economic and environmental impacts of these geomorphic processes using social survey methods of data collection and shoreline change analysis. The main research tools used include questionnaire survey, interviews and Digital Shoreline Analysis System (DSAS) 4.2 software using extracted shorelines of 1926 ground survey sheet and 2008 Landsat ETM+ image to determine shoreline change between the periods. The research identified some environmental and socio-economic impacts of the sea erosion on the coastal community, and these include the destruction of coastal ecosystems and infrastructure such as offices of institutions, school blocks and roads. The ramifications of these problems include homelessness, unemployment and poverty, which compel victims to migrate. Results of shoreline change analysis indicate that, the Ada Foah shoreline has been receding since 1926 to date with a mean change in shoreline of 280.49?m and an average annual rate of 3.46?m/year. To protect the coastline from the battering sea, a sea defence project, comprising sand nourishment and the construction of groynes, is being undertaken. 相似文献
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Using time series analysis to assess tidal effect on coastal groundwater level in Southern Laizhou Bay,China 
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下载免费PDF全文 Chen She-ming Liu Hong-wei Liu Fu-tian Miao Jin-jie Guo Xu Zhang Zhou Jiang Wan-jun 《地下水科学与工程》2022,10(3):292-301
Sea water intrusion is an environmental problem cause by the irrational exploitation of coastal groundwater resources and has attracted the attention of many coastal countries. In this study, we used time series monitoring data of groundwater levels and tidal waves to analyze the influence of tide flow on groundwater dynamics in the southern Laizhou Bay. The auto-correlation and cross-correlation coefficients between groundwater level and tidal wave level were calculated specifically to measure the boundary conditions along the coastline. In addition, spectrum analysis was employed to assess the periodicity and hysteresis of various tide and groundwater level fluctuations. The results of time series analysis show that groundwater level fluctuation is noticeably influenced by tides, but the influence is limited to a certain distance and cannot reach the saltwater-freshwater interface in the southern Laizhou Bay. There are three main periodic components of groundwater level in tidal effect range (i.e. 23.804 h, 12.500 h and 12.046 h), the pattern of which is the same as the tides. The affected groundwater level fluctuations lag behind the tides. The dynamic analysis of groundwater indicates that the coastal aquifer has a hydraulic connection with seawater but not in a direct way. Owing to the existence of the groundwater mound between the salty groundwater (brine) and fresh groundwater, the maximum influencing distance of the tide on the groundwater is 8.85 km. Considering that the fresh-saline groundwater interface is about 30 km away from the coastline, modern seawater has a limited contribution to sea-salt water intrusion in Laizhou Bay. The results of this study are expected to provide a reference for the study on sea water intrusion. 相似文献
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Geo-hazards with characteristics and prevention measures along the coastal regions of China 总被引：1，自引：0，他引：1
China has more than 18,000 km long coastline. Along the coastline, there are various configurations of topography, geomorphology,
and geology condition. In the coastal regions, geological disasters, including seawater intrusion, coast scouring, land subsidence,
karst collapse, soil erosion, collapse-landslide-debris flow (CLDF), and human activity-induced disasters, occur frequently.
All of these disasters have their own forming causes, characteristics, and distribution regions. Seawater intrusion and coast
scouring only occur in the coastal regions while the others occur in both coastal regions and in-land regions. Land subsidence
occurring in the coastal region is of larger scale and entails greater economic loss than that occurring in the in-land region.
For the other disasters, although the scale of disaster in the coastal regions is smaller than that happened in the in-land
regions, the economic loss in the former case is greater than that in the latter. This is because populations are dense and
economy is developed along the coastal regions of China. To mitigate the disasters and reduce the economic loss, countermeasures
are discussed. 相似文献
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为了研究中蒙俄经济走廊沿海与内陆地区归一化植被指数（NDVI）的分布特征,利用MOD13Q1 NDVI数据集、MERRA2气象再分析数据和AVHRR土地覆盖数据,以中蒙俄经济走廊研究区内2种代表性植被（林地和树木茂盛的草地）为例,采用回归分析法和相关性分析法研究了近年来研究区NDVI在不同纬度、距海岸线不同距离及不同时间的变化特征,并分析了气温与降水对NDVI的影响。结果表明：2015—2019年内5月下旬—9月,沿海地区植被生长状态基本优于内陆地区,从距离海岸线500 km左右开始,NDVI明显下降;沿海地区（0~500 km）与内陆地区NDVI在时间变化上也略有不同,沿海地区2种代表性植被的NDVI时序变化模型拟合效果较好。受沿海与内陆地区降水、气温差异影响,在植被生长顶峰期（0719—0723）,随着纬度上升,沿海与内陆地区NDVI差异逐渐减小：沿海地区NDVI在上升期比内陆地区约提前1个月进入饱和,下降期滞后约1个月;低纬度地区2种植被对降水量更为敏感,相关系数最高为0.393（显著性水平P<0.01）,而高纬度地区两种植被对气温更为敏感,相关系数最高为0.534（P<0.01）。 相似文献
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A nested model for the simulation of tides and storm surges in the Bohai Sea, China, has been developed based on the three-dimensional finite-volume coastal ocean model. The larger domain covers the entire Yellow Sea and Bohai Sea with a horizontal resolution of ~10 km, and the smaller domain focuses on the Bohai Sea with a fine resolution up to ~300 m. For the four representative storm surges caused by extratropical storms and typhoons, the simulated surge heights are in good agreement with observations at coastal tide gauges. A series of sensitivity experiments are carried out to assess the influence of coastline change due to land reclamation in recent decades on water levels during storm surges. Simulation results suggest that changes in coastline cause changes in the amplitude and phase of the tidal elevation, and fluctuations of surge height after the peak stage of the storm surges. Hence, for the assessment of the influence of coastline changes on the total water level during storm surges, the amplitudes and phases of both the tidal and surge heights need to be taken into account. For the three major ports in the Bohai Bay, model results suggest that land reclamation has created a coastline structure that favors increasing the maximum water level by 0.1–0.2 m. Considering that during the storm surges the total water level is close to or even exceeds the warning level for these ports, further increasing the maximum water level by 0.1–0.2 m has the potential to cause severe damages and losses in these ports.
相似文献12.
Nicolas Bruneau Juergen Grieser Thomas Loridan Enrica Bellone Shree Khare 《Natural Hazards》2017,85(2):649-667
Catastrophe risk models are used to assess and manage the economic and societal impacts of natural perils such as tropical cyclones. Large ensembles of event simulations are required to generate useful model output. For example, to estimate the risk due to wind-driven storm surge and waves in tropical cyclone risk models, computationally efficient parametric representations of the wind forcing are required to enable the generation of large ensembles. This paper presents new results on the impact of including explicit representations of extra-tropical transitioning in parametric wind models used to force storm surge and wave simulations in a catastrophe risk modelling context. Extra-tropical transitioning is particularly important in modelling risk on the Japanese coastline, as roughly 40 % of typhoons hitting the Japanese mainland are transitioning before landfall. Using both a historical and idealized track set, we compare maximum storm surge and wave footprints along the Japanese coastline for models that include, and do not include, explicit representations of extra-tropical transitioning. We find that the inclusion of extra-tropical transitioning leads to lower storm surge (10–20 %) and waves (5–15 %) on the southern Japanese coast, with significantly higher storm surge and waves along the northern coast (25–50 %). The results of this paper demonstrate that useful risk assessment of coastal flood risk in Japan must consider the extra-tropical transitioning process. 相似文献
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P. Murugavel V. Gopalakrishnan Vimlesh Pant A. K. Kamra 《Journal of Earth System Science》2008,117(1):273-280
Airborne measurements of the number concentration and size distribution of aerosols from 13 to 700 nm diameter have been made at four vertical levels across a coastline at Bhubaneswar (20°25′N, 85°83′E) during the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) programme conducted in March–April 2006. The measurements made during the constant-level flights at 0.5, 1, 2 and 3 km altitude levels extend ～100 km over land and ～150km over ocean. Aerosol number concentrations vary from 2200 to 4500 cm?3 at 0.5 km level but are almost constant at ～ 6000 cm?3 and ～ 800 cm?3 at 2 and 3 km levels, respectively. At 1km level, aerosol number concentration shows a peak of 18,070 cm?3 around the coastline. Most of the aerosol size distribution curves at 0.5 km and 1 km levels are monomodal with a maxima at 110nm diameter which shifts to 70 nm diameter at 2 and 3 km levels. However, at the peak at 1 km level, number concentration has a bimodal distribution with an additional maximum appearing in nucleation mode. It is proposed that this maxima in nucleation mode at 1 km level may be due to the formation and transport of new particles from coastal regions. 相似文献
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三沙湾海岸线时空演变 总被引：1，自引：0，他引：1
海岸带是海陆之间的过渡区域,是人类活动和经济发展较为活跃的地区。海岸线时空演变研究对海岸带资源开发与保护有重要意义,但国内外对三沙湾海岸线时空演变研究较少。本文基于25 a的卫星遥感资料,解译出4个时相的三沙湾海岸线,定量分析海岸线变化趋势,并研究海岸线演变的主要因素。研究表明,25 a的三沙湾海岸线总体长度呈增长趋势：1988-1996年岸线总长度变化不大;2003年较1996年增加约6 947 m、增长约11.5%;2003-2013年岸线总长度增加较为明显,2013年较2003年增加约24 128 m、增长约39.6%,其增速约为1996-2003的3.4倍。砂质岸线长度基本稳定,基岩和泥质岸线长度有所减少,人工岸线在逐年增加,这主要是滩地围垦、港口建设和海岸人工改造等人为因素造成的。 相似文献
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Estuarine and beach deposits in the vicinity of the present coastline at Pakarae River record the infilling of an estuary and subsequent development of a sequence of seven marine terraces during Holocene time.
At the maximum of the last glaciation about 18,000 years ago the shoreline at the ancestral Pakarae River was approximately 20 km east of the present shoreline. By about 9000 years BP the sea had transgressed across most of that coastal plain to lie within a few hundred metres of the base of the present coastal hills. Seventeen radiocarbon ages from estuarine deposits record the overall rise in post-glacial sea level, but in the period c. 9500-7000 yrs BP there are reversals to the overall rising trend. Between 9500 and 8500 yrs BP there appears to have been a eustatic fall in sea level of at least 4 m. This observation is supported by data from several other localities around New Zealand. Maximum transgression occurred about 6500–7000 yrs BP when the sea reached the base of hillslopes and an extensive estuary existed behind a barrier bar.
Since that time the barrier bar disappeared, probably due to stranding in an uplift event, and the coastline advanced progressively outward toward its present position. Coastal progradation (sea level regression) and subsequent erosion have occurred in association with episodic large earthquakes at about 6700, 5400, 3910, 2450, 1570, 1000 and 600 yrs BP. The present distribution of terraces has been influenced by coastal erosion, which has removed all trace of some terraces from some areas, and river erosion has modified the marine terraces near the river. 相似文献
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A coastline is a random fractal object in a geographical system whose length is uncertain. To determine the coastline length of a country or a region, the scaling region and fractal dimension of the coastline is first calculated, and then, the length of the coastline is measured using the scale at the lower limit or near the limit of the scaling region. For this study, the scaling region of the continental coastline of China is determined. The box-counting dimension was calculated with ArcGIS software using 33 scales and a map scale of 1:500,000, and the divider dimension calculated by a C language program. Moreover, the reliability of the Chinese coastline length value, which is widely used currently, is discussed in this paper. The results show that the scaling region of the continental coastline of China is from 0.1 to 400 km. In the scaling region, the box-counting dimension and the divider dimension of the coastline are 1.2004 and 1.0929, respectively. According to fractal theory, the divider dimension more accurately represents the irregularity of a coastline. The length of the continental coastline of China is approximately 21,900 km when the measurement scale is 0.1 km; however, the length is 18,214 km when the scale is 0.25 km, and this value approaches the continental length of China (18,400 km) in popular use today. Although the coastline length is shorter than 21,900 km, the length is acceptable because the measurement scale (0.25 km) is close to the lower limit of the scaling region. 相似文献
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Reconnaissance report on landslide disasters in northeast Japan following the M 9 T��hoku earthquake
Toyohiko Miyagi Daisuke Higaki Hiroshi Yagi Shoji Doshida Noriyuki Chiba Jun Umemura Go Satoh 《Landslides》2011,8(3):339-342
An earthquake of Mw 9.0 struck the Pacific coast in northeast Japan on March 11, 2011 and was followed by a hugely damaging tsunami along 500 km
of the Japanese coastline. An inland aftershock of M. 7.0 occurred on April 11; during which, surface fault ruptures appeared
on land. A large variety of landslide disasters resulted from these earthquakes in various parts of northeastern Honshu, Japan.
The full extent of the landslides is still being determined. This brief report introduces some of the landslide phenomena
so far investigated by the Japanese Landslide Society. These are (1) failure of a water reservoir embankment dam in Sukagawa,
Fukushima prefecture, (2) landslides and surface seismic fault rupture from the April 11 aftershock in Iwaki, Fukushima, (3)
a concentration of surface failures at Matsushima Bay in Miyagi prefecture, and (4) small landslides on modified slopes in
residential areas around Sendai city. 相似文献
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Human impact has increased stunningly during the last century with coastal problems being one manifestation of environmental injustice with ecological, economic, and social dimensions on coastal resources. The study sought to assess the residents’ perception of coastline changes in the milieu of the rampant sand mining activities along the Elmina, Cape Coast and Moree coastline of Ghana. The study employed the purposive sampling technique: 100 respondents were engaged from the selected study areas through simple random sampling method. Interviews, Focus group discussions, observations and questionnaire were the main instruments used. The study revealed that beach sand mining is widespread across the Elmina-Cape Coast-Moree coastline and takes place in several forms, with the magnitude of sand taken from the beach being dependent on the transportation medium and the purpose to which sand is to be put. It is considered that the 1995 National Environmental Policy has become outdated and the sections dedicated to the coastal zone are irrelevant due to new research data and trends in administration. The time is right for a concerted national policy dedicated to only the coastal zone that takes into consideration the multiplicity of use of the zone and adopts an integrated management approach. 相似文献
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美国海岸带自然资源与生态损害评估及修复工作对中国的启示 总被引：1，自引：0，他引：1
海岸带是位于海陆结合部的复杂环境系统,是人类活动最集中的地区。中国大陆海岸线约18000km,涉及沿海11个省,由于经济社会高速发展,海岸带地区的人口、资源、环境矛盾日益突出,面临海岸带资源无序开发、水土污染、滨海湿地退化、海岸侵蚀、地面沉降等一系列生态环境与灾害地质问题,已成为影响生态文明建设的主要问题之一。因此中国持续加大海岸带生态环境保护力度,并提出实施重要生态系统保护和修复重大工程、强化湿地保护和修复等政策措施。美国国家海洋和大气管理局主导的海岸带损害评估及修复计划已实施了近30年,并取得了显著效果,其完善的法律制度体系、规范的损害评估和修复程序、数据集成管理和共享应用等成功经验值得学习借鉴。建议加快完善中国海岸带生态环境损害评估与修复的技术方法体系和制度体系、有序开展海岸带自然资源和生态环境调查、加强海岸带及滨海湿地等重要生态系统的演化和修复技术研究与示范,并构建统一的海岸带基础调查数据库、建立海岸带监测预警体系。 相似文献