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1.
莱州湾东部潮上带土地利用对海岸蚀退的影响   总被引:1,自引:0,他引:1  
基于二维浅水方程、波作用守恒方程和对流扩散方程, 建立了波浪-潮流-泥沙耦合数值模型, 分析了最近20 年来莱州湾东部潮上带土地利用对海岸蚀退的影响。结果显示, 潮上带土地利用改变 了风暴潮时的水动力边界条件, 显著增大了岸线附近的水流流速。随着潮上带养殖设施覆盖比例的 提高, 从平面分布看, 岸线附近侵蚀显著加重, 侵蚀条带平行岸线并向下游延伸、向海侧拓展; 从剖 面分布看, 岸线两侧侵蚀深度显著增大、范围明显扩展, 水下岸坡的闭合水深加大, 闭合点外移; 从 动力条件变化看, 岸线附近水流流速最大。分析表明, 最近20 年来大规模的潮上带土地利用是莱州 湾东部海岸蚀退的重要影响因素。  相似文献   

2.
To achieve an efficient method of coastal rehabilitation, a coastal structure was applied in combination with the mangrove restoration scheme in Sungai Haji Dorani where coastal forest over-cutting associated with erosion has resulted in severe coastline retreat. Such an attempt provides the opportunity to mitigate erosion as well as improve ecological and socio-economic aspects of coastal areas, both of which are of great importance to local communities and authorities. Beach morphological changes were monitored for an eight-month period of time. The results indicate that the attempt has been successful in retaining sediment on the beach and consequently raising the elevation of the site. While the monitoring schedule is required to continue for several years to evaluate long-term performance of the rehabilitation effort, approximately 30% of the transplanted mangrove saplings' survival after eight months shows that the project was moderately successful. Since the general conditions of the selected site represent the majority of the eroded shorelines on the west coast of Peninsular Malaysia, the method applied in this study can be replicated as an appropriate cost-effective alternative for the same cases.  相似文献   

3.
文章利用卫星遥感解译、潮汐数值模拟、GIS空间拓扑分析等技术手段,对水边线进行水位订正,推算出2019年度江苏沿海的遥感海岸线,对江苏省海岸侵蚀现状进行了遥感监测与评估。研究结果表明:2019年江苏省共有侵蚀岸线长58.55 km,占全省大陆海岸线的7.39%。废黄河三角洲侵蚀型海岸的侵蚀岸段平均年侵蚀后退 59.24 m,主要表现为盐养围堤的冲刷水毁;辐射沙洲北翼淤长型海岸的侵蚀岸段年平均侵蚀后退152.28 m,表现为潮间带上部坡度变缓,海岸线持续内移。全省海岸带侵蚀总面积为 7.244 8 hm2,强侵蚀岸段主要分布在南八滩闸北侧,新洋河口两侧以及斗龙港南侧区域。文章同时结合江苏海域动态监管工作经验,提出了5点海岸侵蚀灾害防治对策:①加强天-空-地一体化多手段联合监测,精确监控海岸侵蚀灾害发生范围与程度,了解海岸侵蚀强度与等级;②联合多平台海洋观测,深入开展致灾因素分析,了解海岸侵蚀灾害的发展与变化趋势,逐步完善灾害预警机制;③根据不同的海岸类型与海岸侵蚀特征,有效开展多策略的海岸防护整治,减少海岸侵蚀灾害损失;④加快海岸带保护修复,明确海岸带开发活动的适宜空间与适宜程度,优化海岸带空间布局;⑤强化海岸责任管理,明确监管职责。  相似文献   

4.
Brazilian legislation defines coastal zone as a national patrimony – the geographic space of interaction of air, sea and land formed by the counties directly influenced, but not necessarily by those located in the coastline; also included are those distant until 50 km from the coastline, holding activities of great impact for the coastal zone or its ecosystems. The definition includes also the territorial sea of 12 nautical miles. Coastal management is conducted by a national plan legally enforced, complemented by states and counties plans, and a coastal ecologic-economic zoning limited to small portions of the coastal zone. A resolution of the “Environmental National Council” defines as “permanent preservation areas”, of very restricted use, coastal ecosystems as mangroves, sand dunes, and reproduction sites of wild fauna. One could expect that the Brazilian coast should be more protected and properly managed than other countries where a national management plan is lacking (Argentina) or where the guidelines exist but are not yet legally enforced (South Africa). Notwithstanding, we note today in Brazil an intensification of conflicts opposing small-scale vs. industrial fishermen; shrimp farming vs. mangrove crab harvesting; resorts installation vs. native communities; oil and gas activities vs. NGOs; and conflicts on environmental permit between federal and state governmental agencies. This paper evaluates the possible reasons for the failure of the complex legal suite available in Brazil and suggests that participatory management and concerted actions with relevant stakeholders are the key elements for the successful cases.  相似文献   

5.
海岸线作为海洋与陆地的分界线,是海域管理的重要界限和基础地理数据,也是地图编绘、海洋调查和海岸带演变研究的重要内容,准确掌握其位置、长度等信息,是提高海域管理科学化水平的必不可少的环节。文章结合广东省海岸线修测实际工作中发现的问题,对围海养殖区海岸线界定方法进行探讨。针对养殖区已进行土地确权的情况进行深入分析,并提出:以自然属性为主要依据判定海岸线位置;承认土地权利人的权利在先;围海养殖区的海岸线统一以靠陆一侧的外边缘线进行界定等解决方案。期望可以为海岸线修测和海域管理提供有益的参考。  相似文献   

6.
在2009年3月对鳄鱼海岸线测量的基础上,利用ArcGIS软件分析比较了现有海岸线与厦门市集美区地形图(1988年版,图号:7-50-129甲-)中鳄鱼屿海岸线位置的变化.结果表明21a来,鳄鱼屿海岸最大侵蚀率为2.0 m/a,东南侧最大侵蚀宽度达42 m,侵蚀总面积达14 000 m2;其东北侧海岸侵蚀后退约35 m,侵蚀总面积达4 100 m2;其西北侧海岸最大侵蚀宽度达30 m,侵蚀面积达12 000 m2.文中就厦门市鳄鱼屿海岸侵蚀的成因进行了分析,提出了工程防护、人工补沙、红树林修复以及加强海岛及其周边海域资源综合管理等方面的防护对策.这可为我国其他无居民海岛的海岸侵蚀防护提供经验借鉴.  相似文献   

7.
土地利用变化对芝罘连岛沙坝附近海岸带的影响   总被引:2,自引:0,他引:2  
在RS,GIS技术支持下,经过遥感影像解译获取了研究区1979,1989,1997和2007年4个典型时期土地利用信息,通过对土地利用变化分析,表明近30a来建设用地始终大幅增长,耕地一直大量减少,养殖池和河漫滩从无到有,其他地类呈波动式变化。在快速城市化进程中人类活动对芝罘连岛沙坝附近海岸带产生了深刻影响:其土地利用...  相似文献   

8.
填海造陆对海岸环境的影响主要体现在改变海岸线长度与形态及直接吹填沙导致近海海底地形地貌变化~([1]),这些变化影响着海岸带规划管理和可持续发展,具有重要的理论和现实意义。文章利用滨海新区遥感影像及其海图资料,对该区域近30年海岸线变迁、围填海演变及海底地形信息进行了提取,并对其具体进程和驱动因素进行了研究。研究表明:30年间,滨海新区海岸线变迁是向海洋推进,且推进的趋势越来越明显,岸线长度增长趋势愈发明显,变迁面积较大。针对填海造陆引起围堤基底冲刷问题,笔者建议对中度冲刷区采取防护工程措施、岸外消浪工程和加强动态监测等措施防止泥沙向航道下移。  相似文献   

9.
This article contributes to the understanding of the changes in distribution and total area of mangrove forests along the mainland Tanzania coast over the past decade. Mangroves are recognized as critical coastal habitat requiring protection and special attention. The Tanzania coastline forms a suitable habitat for establishment of mangrove forests. Mangrove forests are distributed from Tanga in the north to Mtwara in the south covering approximately 109,593 hectares from 1988-1990 and about 108,138 hectares in 2000. The largest continuous mangrove stands are found in the districts of Rufiji, Kilwa, Tanga-Muheza, and Mtwara. Comparison of data between these two time periods shows that the geographic coverage of mangroves has no dramatic change in the past decade. The Tanzania Mangrove Management Project and other closely related programs and efforts pertaining to mangrove conservation contribute to direct restoration and natural regeneration of mangroves. This study documents the changes of mangroves and demonstrates that remote sensing and GIS offer important data and tools in the advancement of coastal resource management and ecosystem monitoring. Application of geographic information technologies is critical for improved coastal resources management and decision making for sustainable development in Tanzania.  相似文献   

10.
Remote Sensing of Mangrove Change Along the Tanzania Coast   总被引:1,自引:1,他引:0  
This article contributes to the understanding of the changes in distribution and total area of mangrove forests along the mainland Tanzania coast over the past decade. Mangroves are recognized as critical coastal habitat requiring protection and special attention. The Tanzania coastline forms a suitable habitat for establishment of mangrove forests. Mangrove forests are distributed from Tanga in the north to Mtwara in the south covering approximately 109,593 hectares from 1988-1990 and about 108,138 hectares in 2000. The largest continuous mangrove stands are found in the districts of Rufiji, Kilwa, Tanga-Muheza, and Mtwara. Comparison of data between these two time periods shows that the geographic coverage of mangroves has no dramatic change in the past decade. The Tanzania Mangrove Management Project and other closely related programs and efforts pertaining to mangrove conservation contribute to direct restoration and natural regeneration of mangroves. This study documents the changes of mangroves and demonstrates that remote sensing and GIS offer important data and tools in the advancement of coastal resource management and ecosystem monitoring. Application of geographic information technologies is critical for improved coastal resources management and decision making for sustainable development in Tanzania.  相似文献   

11.
为了查清辽宁省海岸的蚀淤等级和分布,从1990年和2007年遥感图像中提取了17年的岸线变化信息,结合辽宁省908专项海岸带海岸侵蚀特征的调查资料,对全省海岸蚀淤情况进行了等级划分,并对其形成原因进行了分析与评价。结果表明,砂质海岸侵蚀较重的区域主要分布在绥中和熊岳一带,黄海岸段的砂质海岸基本稳定,基岩海岸侵蚀较重的区域主要分布在老铁山一带,粉沙淤泥质海岸侵蚀较重的区域分布在庄河一带。摸清辽宁省海岸蚀淤等级分布,对海岸整治与修复、海岸侵蚀灾害的防治与防护以及海岸带管理具有一定的指导意义。  相似文献   

12.
The main objective of the Conscience project was to develop and test concepts, guidelines and tools for the sustainable management of erosion along the European coastline, based on the best available scientific knowledge and on existing practical experience. Four concepts are potentially capable of providing the nexus between scientific knowledge and management: coastal resilience, coastal sediment cell, favourable sediment status and strategic sediment reservoir. The project has tested the use of these concepts and found that they are useful, provided that they are positioned and linked within a logical structure that we shall call the Conscience “Frame of Reference”, defined in time and space and supported through data and monitoring. Practical experience in six coastal sites in Europe has shown that the use of this Frame of Reference together with these concepts can make management objectives explicit and transparent. It can therefore support the design of an appropriate, resilience based coastal erosion management practice.  相似文献   

13.
为改善临高县海岸带生态环境、提升海岸带生态价值及保障海岸带生态安全,文章在实地考察、文献查阅和资料梳理的基础上,概述了当前临高县海岸带面临的典型生态环境问题,分析生态环境退化的主要原因,提出了海岸带保护修复的对策建议。研究结果表明:临高海岸带地区砂质海岸、红树林、珊瑚礁和白蝶贝等面临较严重的海岸侵蚀、生态环境退化和生物资源枯竭等问题;砂质海岸侵蚀主要受海平面上升、风暴潮等自然因素影响,红树林生态系统主要受围海养殖、环境污染影响,珊瑚礁、白蝶贝等海洋生态系统则主要受渔业捕捞、水体污染等人为活动影响;基于海岸生态退化现状及原因分析,提出文澜河口、抱吴港等岸段开展沙滩喂养及生态堤建设,新盈湾、黄龙湾、金牌湾等重点区实施红树林修复,珊瑚礁、白蝶贝保育区加强自然封育、严防人工干扰等建议措施。  相似文献   

14.
The quantity of coastline retreat resulting from storm erosion is one of the most important phenomena that needs to be accurately quantified to facilitate effective coastal management strategies. Historically, the volume of storm erosion (and coastline retreat) accommodated for coastal planning decisions has been directly linked to the storm (usually defined by considering wave height and duration only) with a certain pre-defined return period, known as a Synthetic Design Storm (SDS) (e.g. 1 in 100 year storm). The SDS method of estimating storm erosion volumes for coastal planning thus assumes that, for example, the 1 in 100 year storm event also results in a 1 in 100 year erosion event. This communication discusses the physical reality of this assumption and demonstrates the improved performance of a new method, based on Joint Probability Distributions (JPD) for estimating storm erosion volumes proposed by Callaghan et al. [Callaghan, D.P., Nielsen, P., Short, A.D. and Ranasinghe, R., 2008. Statistical simulation of wave climate and extreme beach erosion. Coastal Engineering, 55(5): 375–390] using one of the world's longest beach profile surveys from Sydney, Australia.  相似文献   

15.
《Ocean & Coastal Management》2003,46(9-10):859-874
In the area of a coastal fishing village on the mangrove peninsula of Bragança, State of Pará, North Brazil, coastal changes were observed by a beach profile monitoring programme between 1997 and 2001. The assessment allowed a subdivision of the region into four small coastal cells (1–3 km), partly exhibiting heavy erosion. A number of related socio-economic problems, such as loss of alternative income sources caused by the locally unpredictable erosion patterns were identified in three separate village sections. This results in a year-round dependence on seasonally low fishery incomes and increases the risk of poverty. Since limited options for action are available to the local population, different social groups have evolved different land use patterns, which in turn influence local coastal morphodynamics. Not only the hydrodynamic signature, but also the socio-economic organisation of a coastal community and the co-evolutionary path between these two variables thus indicate the state of a coastal system and the most promising policy actions towards sustainable coastal management.  相似文献   

16.
Abstract

Decisions on lake management will often have to be made when data are scarce. However, a nutrient budget based on limited data of varying reliability and on information from the literature may help considerably.

Lake Tutira's recreational uses are threatened by eutrophication. Artificial destratification is being used temporarily to protect the trout fishery. The annual phosphorus input to the lake was estimated from nutrient loading graphs, from scanty stream input data, and from land‐use information to be about 3100 kg (1.8 g·m?2·y?1).

The 5–10 times reduction in phosphorus loading apparently required to achieve mesotrophic to oligotrophic conditions establishes the need for major changes in the catchment. The phosphorus budget helped in assessing the relative importances of the input streams and evaluating stream diversion proposals. It suggested that phosphorus inputs came mostly from animal excreta, soil erosion, and fertiliser, and it provided support for farm management proposals. When the results of stream diversion and altered land management are known the phosphorus budget may help in deciding the optimum land area needed to be converted from pasture into forest.  相似文献   

17.
李爽  詹文欢  姚衍桃 《海洋通报》2019,38(2):210-216
分维数是反映海岸线复杂程度的客观依据。结合国内外海岸线分形研究进展,本文以漠阳江入海口附近海域为研究区,基于Landsat 8 OLI遥感影像对研究区域提取瞬时水边线,并利用潮汐数据进行校正得到海岸线;利用Fractal Fox2.0计算获得该海岸线的分维数为1.071;通过对研究区的分形机制分析,认为漠阳江附近的断裂构造对海岸起宏观控制作用,从而对海岸线的分维值也起了决定作用。根据断裂体系模型计算得到西侧海岸线的理论分维值为1.089,而对数螺线模型计算得到东侧海岸线的分维值为1.171;实际分维值相对理论值偏小,说明海岸带的沉积与侵蚀影响了分维值。此外,根据本区海岸侵蚀原因的分析,对分维机制进行了探究,初步论证的分维值大小可为海岸的冲淤变化研究提供参考。  相似文献   

18.
Increasing intense human activities have largely changed the coastal landscape and caused many environmental issues. However, whether human-induced activities could change the coastal land use gradient pattern, an important coastal zonal characteristic along the sea–land direction, remains unclear. Manila Bay was selected as the study area in this work. According to the distance of the land use and land cover(LULC) to the coastline, we clustered the typical coastal land use sequence patterns(CLU...  相似文献   

19.
为了分析珠江口区域海岸线近年来的发展变化情况,文章基于分形理论,分别对珠江口及深圳段大陆海岸线2005-2019年的变迁趋势采用网格法进行分形分析,得出14年间,珠江口及深圳段海岸线分维数的变化情况。通过对计算结果的分析对比发现,近年间珠江口海岸线整体因开发强度大,人工岸线居多,分维数值变化较小;而深圳段海岸线分维数较整个珠江口有较大幅度增加。深圳段海岸线曲折度提高的原因主要为修复类工程的实施。海岸线分形维数与海岸线曲折程度的正相关系,与海岸带开发利用规划管理要求相符,提出分维数可作为规划用海的重要评估参数。  相似文献   

20.
苏北废黄河三角洲海岸时空演变遥感分析   总被引:4,自引:0,他引:4  
基于遥感与地理信息系统技术,使用苏北废黄河三角洲海岸地区1978,1987和2000年的Landsat卫星遥感数据,选取岸线指标与波段,提取岸线信息,生成1978-1987年和1987-2000年海岸土地增减时空变化分布图,建立岸线变化距离及增速衡量指标,定量分析了废黄河三角洲海岸面积变化特征,以及灌河口-中山河口、中山河口-扁担港口和扁担港口-双洋河口以南岸段的时空变化格局与分布特征.研究结果表明,废黄河三角洲海岸的自然侵蚀速率呈减小趋势,但侵蚀作用仍在继续.侵蚀强度以废黄河口地区为中心,向南北两侧逐渐减弱.人工保滩护岸措施在一定程度上影响着自然侵蚀格局.其内部各岸段分别呈现缓蚀、侵蚀和基本侵淤平衡的变化格局.  相似文献   

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