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31.
1973 年以来射阳河口附近海岸蚀淤变化遥感分析 总被引:1,自引:0,他引:1
以射阳河口北部扁担港口和射阳河口南部斗龙港口之间的海岸作为研究区,基于1973,1987,2000和2013年四期Landsat影像提取了该岸段岸线,并进行了时空变化分析。结果表明,射阳河口以北的扁担港口—射阳河口岸段仍处于侵蚀状态,呈现侵蚀—淤积—缓慢侵蚀的变化格局,40 a间侵蚀面积为12.6 km2,淤积面积为1.0 km2;射阳河口以南的射阳河口—斗龙港口岸段处于淤积的态势,呈现淤积—快速淤积—缓慢淤积的格局,40 a间淤积的面积为223.1 km2,仅在2000~2013年间该岸段北部出现了侵蚀。结论是虽然射阳河口以南岸段仍总体处于淤积的过程中,但是近年来江苏海岸的侵蚀范围已经扩展到了射阳河口以南,这证明了江苏海岸侵蚀岸段有进一步扩大的趋势。 相似文献
32.
介绍了1991年11月5日江苏射阳M_s4.7级地震较成功的预测经验和前兆特征,以期在东部地区建立一个震级接近5级的震例,作为地震预报实用化应用的成功尝试. 相似文献
33.
江苏射阳县滩涂资源的开发利用及发展规划 总被引:6,自引:0,他引:6
射阳县现有滩涂面积674.6km^2,目前还在以2.2km^2/a的速度淤涨。该区海岸带动力复杂,生物多样性程度高,海岸带由侵蚀向淤积过渡。滩涂开发中潮间带利用率低于潮上带,土地资源潜力大。但滩涂利用中存在着许多问题,如开发利用程度低、效益差,产业部门之间矛盾突出,环境污染严重,滩涂生态环境退化,科技水平低,基础设施落后等。根据该区资源条件,其滩涂开发重点应放在种植业、水产养殖业、林业、畜牧业、港口工业和旅游业等方面,并重视“两带”、“三区”、“三大基地”项目建设。 相似文献
34.
叙述了1993年前的芦潮港车客渡码头水域自然水深条件和1993年后强烈淤涨的态势,从诸事件的时间之窗及水下滩坡适应性调整、长丁坝促淤效应等方面讨论了该水域强势淤涨的原因,提供了一个海岸工程产生淤积响应的典型实例。海岸带(尤其在沉积环境响应敏感的区域)开发必须注重社会经济效益与环境效益的统一。 相似文献
35.
36.
利用江苏重力测网2014—2017年重力场观测资料,采用绝对重力控制与相对重力联测相结合的平差方法,获取2016年射阳M_S 4.4地震前后重力场变化图。根据射阳M_S 4.4地震前后射阳地区各测线重力段差变化特点,绘制重力场等值线并进行对比分析,结合相关机理,探讨重力场变化与该地震的内在联系。同震观测数据显示:射阳M_S 4.4地震发生在重力异常值高梯度带附近,发震时震中地区位于NS挤压正异常、EW张拉负异常状态,震后区域重力梯度变化量开始减小,是一种典型的重力异常调整现象。 相似文献
37.
Manel Grifoll Almudena Fontán Luis Ferrer Julien Mader Manuel González Manuel Espino 《Coastal Engineering》2009
A background knowledge of marine dynamics helps harbour managers to control pollution and to manage dredging and traffic operations. This contribution studies the hydrodynamic conditions within Bilbao Harbour, which is enclosed by the Nervión Estuary (in the Basque Country, Spain). The results obtained from hydrographical surveys are compared with numerical simulations obtained using the Regional Ocean Modelling System (ROMS). Hydrodynamic modelling was carried out to determine the inner harbour currents for a specific period in which data were available. Then, numerical experiments were designed in order to quantify the importance of different driving mechanisms in the harbour hydrodynamics. The results show that, in addition to the strong tidal influence on water circulation, the wind forcing and freshwater discharge also have a non-negligible influence on the currents. The computational domain is complex due to the presence of harbour infrastructures (i.e. breakwaters and piers). As a result, topographic eddies are therefore observed in the results. The freshwater influence of the Nervión river can also be observed in residual currents. This paper presents an improvement to the application of numerical modelling to a complex geometry domain, contributing to our understanding of the behaviour of the marine systems in meso-tidal harbours. This can be used to deal with harbour engineering and management problems. 相似文献
38.
Mahmoud M. El Banna 《Environmental Geology》2007,52(1):41-49
Beach profile data, covering the coast of Ras El Bar, northeast Nile Delta, collected during the years from 1990 to 2002 combined
with landsat images for the area and sedimentological investigation have been used to identify beach and nearshore seafloor
sediment changes. Along the coast of Ras El Bar, two accretion sectors and one of erosion have been recognized. The first
accretion sector is located west of Damietta harbour, where the harbour jetties have halted the littoral transport, while
the second one is behind a system of detached breakwaters protecting Ras El Bar resort. Both the two sectors are characterized
by growing shoreline with maximum rates ∼15 and 10 m/year, respectively. Also, they have maximum nearshore seafloor accretion
rates of ∼18 and 22 cm/year, respectively. The erosion sector is located east of Damietta port and has a maximum rate of shoreline
retreat ∼−10 m/year. Erosion of its nearshore seafloor is indicated recording a maximum rate of ∼−20 cm/year. The rate of
net sediment volume change in the area indicates shifting of the accretion sector (II) westward, responding to installation
of the new breakwaters unit. The two accretion sectors are characterized by dominance of moderately sorted fine sands in their
shore area which change seaward into less sorting very fine sands. Beach sands of the eroded sector are poorly sorted medium
grain size. The dominant constituents of heavy mineral species in beach and sea-bottom sands are the characteristic assemblages
of the Nile deposits. The sands of the eroded zone are relatively enriched in monazite, zircon, tourmaline, garnet, and rutile. 相似文献
39.
Nick Marriner 《Quaternary Research》2006,65(1):164-171
Chrono-stratigraphic data from Tyre's ancient northern harbour delineate extensive dredging practices during the Greco-Roman and Byzantine periods. Radiocarbon dates from four cores consistently cluster between ca. 500 B.C. and 1000 A.D. and indicate rapid rates of sedimentation in the basin, namely ∼10 mm/yr during the Greco-Roman and Byzantine periods, compared to 0.5-1 mm/yr for the period 6000-4000 B.C. Absence of strata between 4000 B.C. and 500 B.C. is not consistent with a natural base-level sediment sink and cannot be interpreted as a depositional hiatus in the high-stand systems tract. Ancient dredging is further corroborated by persistent age-depth inversions within the fine-grained harbour facies. These data support removal of Middle Bronze Age to Persian period sediment strata, with deliberate overdeepening of the harbour bottom by Greco-Roman and Byzantine societies. 相似文献
40.
于2011年5月~2012年4月,对正在建设港口及其邻近海域环境进行为期一年的监测,研究港口建设引起的悬浮物变化,及其对海域重金属污染物和生物群落的影响。研究结果表明:(1)海域悬浮物的变化范围为1.2~147.5mg/L,底层悬浮物含量显著高于表层,悬浮物含量受季节自然因素和工程建设人为因素的双重影响;(2)水体中重金属含量呈现升高趋势,与悬浮物含量变化的关系不明显;(3)海域浮游植物密度和群落特征指数均较低,甲藻比例明显增加;浮游动物密度和各群落特征相对正常;底栖生物面临较大压力。 相似文献