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1.
陆海统筹是我国海岸带地质工作的重要方向,但以往的海岸带地质工作通常按陆区和海区分别开展,对如何实现陆海统筹没有形成统一认识。上海作为我国率先开展海岸带地质工作的地区之一,在陆海统筹方面进行了一些有益尝试,积累了一定经验。基于这些实践经验,并结合国内外海岸带地质工作现状,对海岸带地质工作中陆海统筹的方法论进行了探讨,提出了海岸带地质工作中陆海统筹应包含陆海成果一体化和以水体为媒介实现陆海联动的两个基本要求。研究认为: 在外业工作部署上,应发挥陆区河流和海区海岛的中介作用,着眼于区域性而非局部地区的地质成果编制; 在地质环境监测上,以海堤或岸线为纽带对陆区和海区进行同步监测; 在成果图件编制上,为实现陆海成果的有机整合,统一陆海数据标准是关键,在保存数据科学信息的前提下适当简化数据等级的分类。 相似文献
2.
主要针对福建沿海与海域的海平面变化、海湾淤积、活动断层、海岸侵蚀与海域内潜在的地质灾害及其危害性进行讨论 ,并对其危害提出防治建议。 相似文献
3.
相对海平面上升的危害与防治对策 总被引：2，自引：0，他引：2
胡俊杰 《地质灾害与环境保护》2005,16(1):66-70
相对海平面上升已成为中国沿海地区海洋地质环境灾害之一。本文在有关学者以往研究工作的基础上,对中国相对海平面上升所造成的危害作了进一步探讨,并提出一系列防治对策。相对海平面上升能够在沿海地区造成海岸侵蚀、风暴潮灾害加剧、海水入侵、水资源和水环境遭到破坏、沿海低地被淹、防汛工程功能降低等诸多灾害。为了减缓这些灾害,采取一定的防治对策是十分迫切和必要的,其中加强海平面变化监测和科学研究是基础,提高海堤标准、加强海堤管理与保护、施行海滩人工喂养是关键,此外还要辅以公众意识的提高。 相似文献
4.
晚更新世江苏海岸带沉积分布模拟研究 总被引：1，自引：0，他引：1
中国边缘海大陆架在晚更新世时期曾是海岸平原,在古长江、古黄河泥沙填充下形成了陆架堆积体,并在全新世发育了南黄海辐射沙脊群、废黄河三角洲和长江三角洲。根据点状的地质钻孔分析和重建,对南黄海-江苏海岸的沉积体系的分布和变化机制尚不明了。作为动力机制探讨,基于气候-海面-沉积系统,根据气候水文学、沉积学原理以及泥沙沉积面的动态高程计算,构建了气候冰川驱动-东黄海地海系统响应-河流沉积建造的数值模式,模拟了14万年、4万年和1万年不同时间尺度江苏海岸线和长江三角洲沉积的变化过程和分布,进而对冰川气候、构造沉降、沉积压实等复杂效应下的海面特征、陆源泥沙沉积和海岸线进行分析。模拟结果与地质钻孔资料揭示的层序和埋深能够进行对比。 相似文献
5.
中国沿海地质环境与区域持续发展的若干问题探讨 总被引：2，自引：1，他引：2
本文分析了中国沿海岩石圈动力学的基础特征, 指出中国东部沿海地质环境与灾害存在南北分异的格局, 阐述了沿海区域工程地质环境的基本规律, 并通过全球及中国近百年海平面变化, 以及人类工程活动对河口海岸地质环境影响的分析, 对沿海地区未来的地质环境与灾害趋向做了初步评估, 并认为中国沿海21世纪的环境与发展将面临严峻的挑战, 特别是环渤海地区。最后, 对影响沿海区域发展的若干问题进行了初步探讨并提出了几点建议。 相似文献
6.
《上海国土资源》2010,31(3):1-8
2010年9月16日上午,本刊主编、上海市地质调查研究院总工程师严学新教授与本刊编辑部主任、上海市地质调查研究院总工程师办公室副主任龚士良教授,在华东师范大学河口海岸国家重点实验室恽才兴教授的陪同下,专程拜访了我国河口海岸学科的先驱、中国工程院院士、华东师范大学河口海岸研究院名誉院长陈吉余教授,在陈院士90华诞前夕对他进行了专访。陈院士针对上海后备土地资源、滩涂合理开发利用、生态湿地保护与置换、海岸带地质工作拓展、海平面上升与城市安全、人工岛及港岛建设、人类第三驱动力的作用效应等诸多社会广泛关注的热点问题发表了独到见解和精辟论述,强调指出：上海城市发展与资源利用必须坚持＂发展、合理、公平、协调＂八字方针,并对本刊提出殷切希望。 相似文献
7.
We conducted archaeological and geophysical surveys in order to investigate the submergence of ancient constructions along the coast at Kekova Island in southern Turkey. Submerged archaeological remains were measured with respect to present sea level, and geological features that may have caused subsidence were determined by seismic investigation. We estimated relative sea‐level change taking into account presumed original elevation of constructions associated with the harbor at the time of occupation and compared our results with eustatic–isostatic sea‐level studies in the Mediterranean. Ceramics found along the submerged quay of Kekova Island provided evidence for the time of last use of the harbor structures and suggest that submergence began during the early Byzantine period. Considering relative sea‐level changes, eustatic–isostatic effects, and the period of submergence, we estimate a rate of coastal tectonic subsidence of at least 1.6 mm/yr over the last 1400 years. 相似文献
8.
The Yalgorup Plain of southwestern Australia is underlain by two limestone formations and a linear quartz-sand formation containing limestone lenses. These limestones record carbonate deposition in seagrass banks during the Pleistocene; they are capped either by a prograding beach-ridge system of small cuspate forelands or a quartz-rich shore-parallel coastal barrier. The cuspate forelands formed behind protective offshore limestone reefs within a given Pleistocene wind-and-wave field, while the quartz-rich coastal dune barrier formed under enhanced swell conditions. These formations record three different Pleistocene interglacial depositional events, separated by unconformities, each linked to a distinct climate and mean sea level. Foraminiferal assemblages within the two limestones and within the limestone lenses of the quartz-sand formation faithfully record changes in minimum seawater temperature, reflecting these changes in climate. They indicate a cycle of warm–cool–warm water accumulation of carbonates. Such a record of both climate and sea level history for southwestern Australia is unique, contributing greatly to the Pleistocene coastal sedimentary history of limestones within southwestern Australia. These formations occur within the globally unique setting of Western Australia and are conserved within a National Park and represent an outstanding record of Quaternary coastal geomorphic development in terms of both carbonate and siliciclastic sedimentation linked to both climate and sea level changes. Given their array of lithofacies, environmental setting, sea level and climate changes, as well as their biostratigraphy reflecting these changes, these formations form a sedimentary ‘package’ that is of global geoheritage significance, with many of its inherent geological features also of global to national geoheritage significance. 相似文献
9.
Archaeological sites in the northern Ha'apai Group of central Tonga occur on small islands within the uplifted forearc belt of the Tonga-Kermadec arc-trench system. The present inland positions of occupation sites that probably once occupied coastal settings imply significant expansion of some island shorelines during late Holocene time (ca. 3250 B.P. to present). Geologic processes leading potentially to enlargement of the islands include continuing forearc uplift, eustatic or glacio-hydro-isostatic fall in sea level following a mid-Holocene highstand, and progressive accretion of beach ridges to island coasts, with or without changes in relative sea level. Radiometric dates for uplifted coral terraces in Tonga indicate that forearc uplift has been negligible during Holocene time. By contrast, theoretical considerations, regional analysis of shoreline indicators throughout the South Pacific, and limited empirical data from Tonga itself all imply that regional sea level has declined locally by 1–2 m since a mid-Holocene highstand (ca. 6000-3000 B.P.), which was a hydro-isostatic response to transfer of water mass from Pleistocene ice caps to the ocean basins. Emergence of originally coastal sites is thus expected since initial settlement of the islands by Lapita peoples. Accretionary coastal flats composed of multiple beach ridges are 250–500 m wide on favorable leeward shores and the flanks of sand cays, but some presently unknown proportion of this incremental island growth may have occurred prior to the post-mid-Holocene decline in relative sea level. Ash falls from tephra eruptions at Tongan volcanoes also modified island environments through Quaternary time. Evidence for significant change in the configuration and morphology of islands in Ha'apai during the period of human settlement highlights the need for systematic interdisciplinary archaeological and geological research in the study of Pacific prehistory. © 1994 John Wiley & Sons, Inc. 相似文献
10.
Anthony C. Massey W. Roland Gehrels Dan J. Charman Glenn A. Milne W. Richard Peltier Kurt Lambeck Katherine A. Selby 《第四纪科学杂志》2008,23(5):415-433
Previous sea‐level studies suggest that southwest Britain has the fastest subsiding coastline in the United Kingdom, but tide‐gauge data, GPS and gravity measurements and geophysical models show little evidence of anomalous subsidence in this region. In this paper we present 15 new sea‐level index points from four coastal barrier systems in south Devon. Eight are from compaction‐free basal sediments and others were corrected for autocompaction. Our data suggest that relative sea level along the south Devon coastline has risen by 21 ± 4 m during the past 9000 years. Sea‐level rise slowed during the middle and late Holocene and a rise of 8 ± 1 m has occurred since ca. 7000 cal. yr BP. Anomalous ages for many rejected points are attributed to sediment reworking during barrier transgression. The relative sea‐level history during the early and middle Holocene shows a good fit with geophysical model predictions, but the geological and modelled data diverge in the later Holocene. Unlike the geophysical models, sea‐level index points cannot differentiate between late Holocene relative sea‐level histories of south Devon and southwest Cornwall. It is suggested that this discrepancy can be resolved by obtaining additional high‐quality sea‐level index points covering the past 4000 years. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
11.
近10年来,我国海洋地质工作在海岸带、近海与管辖海域、大陆架边缘海和深海大洋开展了地质构造、矿产资源、环境灾害和探查技术及仪器设备等方面的调查研究和研发,取得一系列重要成果。如历时8年的“我国近海海洋综合调查与评价”专项(908专项),完成了1∶100万管辖海域的16个图幅、1∶25万13个图幅的综合调查和9个区块海砂资源评价; 在南海北部琼东南盆地发现了3个大气田; 开展了海岸带环境地质调查评价与图集(1∶400万)编制; “南海深海过程演变”专项研究与南黄海陆架区科学钻探均有新发现; 海底石油勘探与开发技术(“海洋石油981”钻井平台)、南海北部海域天然气水合物探测技术及发现(Ⅱ型天然气水合物、可燃冰冷泉)、南海天然气水合物试采成功,以及海底探测技术与采样设备的研发等等取得了实质性进展或突破。这些重要成果极大地提高了我国海洋地质调查的程度、研究水平和综合实力。 相似文献
12.
Maren Brehme Traugott Scheytt Mehmet Çelik Uğur Erdem Dokuz 《Environmental Earth Sciences》2011,63(6):1395-1408
The degradation of ground water quality due to human activities is a widespread environmental problem. Furthermore, coastal aquifers are threatened by sea water intrusion as a result of increasing water exploitation. The investigation area near Dörtyol is located at the Mediterranean coast, southern Turkey, and dominated by agricultural land use. Drinking, domestic and agricultural purposes require different amounts of uncontaminated water. In this study the hydrogeological characteristics of the coastal plain were investigated. Discharge and ground water level measurements as well as geological investigations were undertaken in field in addition to anion and cation analyses of ground and surface water. The results show geological and anthropogenic influence on ground and surface water composition. In spite of a large number of wells in the coastal area sea water intrusion was not detected. With the goal of devising sustainable water use regulations, more emphasis and research needs to be directed to the long-term observation of ground and surface water quality as well as the detailed investigation of hydraulic characteristics of the local aquifer. 相似文献
13.
Incised valleys are canyon‐like features that initially form near the highstand shoreline and evolve over geological time as rivers erode into coastal plains and continental shelves to maintain equilibrium‐gradient profiles in response to sea‐level fall. Most of these valleys flood during sea‐level rise to form estuaries. Incised‐valley morphology strongly controls the rate of creation of sediment accommodation, valley‐fill facies architecture and the preservation potential of coastal lithosomes on continental shelves, and affects coastal physical processes. Nonetheless, little is known about what dictates incised‐valley size and shape and whether these metrics can be used to explain principal formation processes. The main control on alluvial channel morphology over human time scales is discharge; this is based on numerous empirical studies and is well‐constrained because all variables are easily measured at this short time scale. Knowledge of long‐term river evolution over a complete glacio‐eustatic cycle, on the contrary, remains largely conceptual, experimental and based on individual systems because variables that are thought to drive morphological change are not easily quantified. In spite of this difficulty, existing models of incised‐valley formation at the coast suggest that valley evolution is driven largely by downstream forcing mechanisms, highlighting sea‐level and shelf gradient/morphology as the dominant controls on valley incision. Although valleys are cut by rivers, whose channels are a direct reflection of discharge, little empirical data exist in coastal areas to address the degree to which valley evolution is governed by upstream controls. The late Quaternary is the best time period to examine because it provides the most complete sedimentary record and many variables, including sea‐level, tectonics, substrate lithology and drainage network characteristics, are accurately constrained. Here, 38 late Quaternary valleys along the coast of two different passive continental margins are compared, which suggests that valley shape and size are governed primarily by upstream, intrinsic controls such as discharge. Valley width, depth and cross‐sectional area are found to be predictable at the highstand shoreline and are scaled with the size of their drainage basin, which has important implications for estimating sediment discharge to continental shelves and deep water environments during periods of low sea‐level. 相似文献
14.
《China Geology》2019,2(1):40-48
Engineering construction actively occurs in coastal zones, and these areas have numerous potential geological hazard factors. Since 2009, the development of geological surveys in sea areas has promoted extensive geophysical surveys in Qingdao offshore. In the present study, the types and distribution of potential geological hazard factors were systematically revealed using sub-bottom profile data, side-scan sonar data, and single-channel seismic data, among others. Based on previous research findings, the potential geological hazard factors are classified, and control factors in Qingdao offshore are discussed. The research results show that the primary potential geological hazards include active faults, buried paleo channels, shallow gas, irregular bedrock, eroded gullies, estuary deltas, tidal sand ridges, and seawater intrusion. In addition, neotectonic movement, sea level changes and sedimentary dynamic processes were the main factors that affected the distribution of geological hazards in Qingdao offshore.©2019 China Geology Editorial Office. 相似文献
15.
High-resolution seismic records obtained in the Rio Grande do Sul coastal zone, southern Brazil, revealed that prominent valleys and channels developed in the area before the installation of actual coastal plain. Landwards, the paleoincisions can be linked with the present courses of the main river dissecting the area. Oceanwards, they can be linked with related features previously recognized in the continental shelf and slope by means of seismic and morphostructural studies. Based mainly on seismic, core data and geologic reasoning, it can be inferred that the coastal valleys were incised during forced regression events into the coastal prism deposited during previous sea level highstand events of the Quaternary. Seismic data has revealed paleovalleys up to 10 km wide and, in some places, infilled with up to 40 m thick of sediments. The results indicated two distinct periods of cut-and-fill events in the Patos Lagoon area. The filling of the younger incision system is mainly Holocene and its onset is related to the last main regressive event of the Pleistocene, when the sea level fell about 130 m below the actual position. The older incision and filling event is related to the previous regressive–transgressive events of the Middle and Late Pleistocene. The fluvial discharge fed delta systems on the shelf edge during the sea level lowstands. The subsequent transgressions drowned the incised drainage, infilling it and closing the inlets formerly connecting the coastal river to the ocean. The incised features may have played a significant role on the basin-margin architecture, facies distribution and accommodation space during the multitude of up and down sea level events of the Quaternary. 相似文献
16.
上海地区未来海平面上升及产生的可能影响 总被引：5，自引：0，他引：5
未来海平面变化,特别是由于地面沉降等引起的相对海平面上升,将对沿海地区的地质环境及人类的生存发展产生极大的影响,通过对影响上海地区海平面变化主要因素的概括,对未来的相对海平面变化作出了预测,对由海平面上升引起的环境效应作了阐述,提出了相应的防治对策。强调了控制上海地区的地面沉降,以减轻海平面上升所造成的危害,具有特殊而重要的意义。 相似文献
17.
Influence of glacial isostatic adjustment upon current sea level variations in the Mediterranean 总被引：1，自引：0，他引：1
Present-day sea level variations in the Mediterranean depend on various factors, including recent climatic forcing, tectonic activity, anthropogenic effects, and glacio-isostatic adjustment. The latter is governed by mantle rheology and the spatio–temporal distribution of the late-Pleistocene ice sheets and it is expected to produce a long-wavelength pattern of sea level variations across the Mediterranean, mostly determined by the response of the solid earth and of the geoid to loading effects of melt water since the end of deglaciation. Modeling glacio-isostatic effects in this region is necessary for a correct interpretation of tide gauge and GPS time-series, and thereby to constrain both the present-day climate-related sea level rise and regional or local geological, tectonic and human-driven displacements. By an exhaustive exploration of the parameter space of mantle rheology and ice sheet chronologies, in this work we outline upper and lower bounds on the current rate of sea level variation associated with glacial isostatic adjustment in the Mediterranean. This may contribute to a full assessment of coastal vulnerability by sea level rise on a regional and local scale. 相似文献
18.
海南省海洋地质调查主要进展与成果 总被引：1，自引：0，他引：1
在中央和地方的共同推动下,海南省海洋地质调查工作取得了长足的进步。为进一步提升海南省海洋地质工作效果,对近年来实施的海洋地质调查工作的主要进展进行了综述,其成果可分为4个方面,即海洋区域地质调查、海岸带与海湾地质环境综合调查与评价、海砂资源调查与评价和岛礁综合地质调查。其中: 1∶100万的海洋区域地质调查已实现了全覆盖,1∶25万的已开展3个图幅工作; 海岸带与海湾地质环境综合调查与评价工作已全面开展,基本查明了本岛沿岸20 m水深以浅的地质概况,重点岸段调查比例尺可达1∶5万,较系统地梳理了海岸带的地质资源与环境现状; 海砂资源调查与评价主要针对锆、钛砂矿和建筑用海砂开展,初步查明了海南岛周边陆架区沉积物类型和海砂潜力分布区,对成矿条件较好的海域开展了详细勘查,圈定了多个海砂开发矿产地; 岛礁综合地质调查工作主要查明了其基础地质条件和开发利用现状,对海岛的进一步开发和管理提出了建议,同时系统地开展了西沙群岛的海陆统筹地质调查工作,掌握了大比例尺的基础地质数据,并研究了其形成和演化过程,为三沙的海岛建设提供了依据。通过地质调查,获得了海南省基础海洋地质数据,查明了海洋资源和环境概况,为海南省的海洋经济发展提供了可靠的地质支撑。 相似文献
19.
Beach erosion under rising sea‐level modulated by coastal geomorphology and sediment availability on carbonate reef‐fringed island coasts 
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下载免费PDF全文 Bradley M. Romine Charles H. Fletcher L. Neil Frazer Tiffany R. Anderson 《Sedimentology》2016,63(5):1321-1332
This study addresses gaps in understanding the relative roles of sea‐level change, coastal geomorphology and sediment availability in driving beach erosion at the scale of individual beaches. Patterns of historical shoreline change are examined for spatial relationships to geomorphology and for temporal relationships to late‐Holocene and modern sea‐level change. The study area shoreline on the north‐east coast of Oahu, Hawaii, is characterized by a series of kilometre‐long beaches with repeated headland‐embayed morphology fronted by a carbonate fringing reef. The beaches are the seaward edge of a carbonate sand‐rich coastal strand plain, a common morphological setting in tectonically stable tropical island coasts. Multiple lines of geological evidence indicate that the strand plain prograded atop a fringing reef platform during a period of late‐Holocene sea‐level fall. Analysis of historical shoreline changes indicates an overall trend of erosion (shoreline recession) along headland sections of beach and an overall trend of stable to accreting beaches along adjoining embayed sections. Eighty‐eight per cent of headland beaches eroded over the past century at an average rate of ?0·12 ± 0·03 m yr?1. In contrast, 56% of embayed beaches accreted at an average rate of 0·04 ± 0·03 m yr?1. Given over a century of global (and local) sea‐level rise, the data indicate that embayed beaches are showing remarkable resiliency. The pattern of headland beach erosion and stable to accreting embayments suggests a shift from accretion to erosion particular to the headland beaches with the initiation of modern sea‐level rise. These results emphasize the need to account for localized variations in beach erosion related to geomorphology and alongshore sediment transport in attempting to forecast future shoreline change under increasing sea‐level rise. 相似文献
20.
Meenu Rani Sufia Rehman Haroon Sajjad B. S. Chaudhary Jyoti Sharma Sandeep Bhardwaj Pavan Kumar 《Natural Hazards》2018,94(2):711-725
Vizianagaram–Srikakulam coastal shoreline consisting of beaches, mangrove swamps, tidal channel and mudflats is one of the vulnerable coasts in Andhra Pradesh, India. Five site-specific parameters, namely rate of geomorphology, coastal elevation, coastal slope, shoreline change and mean significant wave height, were chosen for constructing coastal vulnerability index and assessing coastal landscape vulnerability. The findings revealed a shift of 2.5 km in shoreline towards the land surface because of constant erosion and that of 1.82 km towards the sea due to accretion during 1997–2017. The rate of high erosion was found in zones IV and V, and high accretion was found in zones II and III. Coastal vulnerability index analysis revealed constant erosion along shoreline and sea level rise in the study area. Most of the coast in zone V has recorded very high vulnerability due to erosion, high slope, significant wave height and sea level rise. Erosion and accretion, significant wave height, sea level rise and slope are attributed to high vulnerability in zones III and IV. Zone II recorded moderate vulnerability. Relatively lower slope, mean sea wave height and sea level rise have made this zone moderately vulnerable. Very low vulnerability was found in zone I, and low vulnerability was recorded in zone II. Accretion, low slope and low sea level rise were found to be causative factors of lower vulnerability. Thus, zones III, IV and V should be accorded higher priorities for coastal management. The findings can be helpful in coastal land planning and management and preparing emergency plans of the coastal ecosystems. 相似文献