共查询到17条相似文献，搜索用时 149 毫秒
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江苏省实施“海上苏东”战略以来,开发百万亩沿海滩涂可谓功不可没,用仅仅几年时间就将可围垦的潮上带滩涂基本全部围起来了,5年等于20年。 相似文献
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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
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最近50年来莱州湾东部典型砂岸潮上带土地利用变化研究 总被引：3，自引：1，他引：2
以不同时期测量和成像的地形图和高分辨率遥感影像为数据源,综合使用野外调查、遥感(RS)、全球定位系统(GPS)和地理信息系统(GIS)等方法,对最近50多年来莱州湾东部砂岸典型岸段(界河口—刁龙嘴)的土地利用变化进行研究。结果表明,最近50多年来,莱州湾东部海岸土地利用/土地覆被变化显著,土地利用类型转化的总趋势是风沙地、林地、耕地向养殖池及居民地转化。从20世纪90年代初以来,该岸段潮上带风沙地大部分已为养殖池(塘、大棚)等所覆盖,在沿海防护林和海域之间新出现了一条平行于岸线、基本连续展布的水产养殖设施带,其外侧建有高出当地最高潮位的防浪堤。潮上带土地覆被的如此深刻变化,必然深刻地改变风暴潮作用时的水动力边界条件,导致风暴潮作用过程中沿水下岸坡—海滩—潮上带方向的能量分布发生调整,进一步会对海岸地貌及冲淤发生的范围、强度、性质和形式等带来变化。因此,大面积的潮上带土地利用可能是莱州湾东部砂岸,最近30年来海岸地貌冲淤演变的重要影响因素之一,这为今后深入研究并预测该段海岸地貌冲淤变化提供了新的视角。 相似文献
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运用稳定同位素方法分析了盐城滨海湿地生态系统中部分生物的食物来源,示踪了食物网的主要碳流途径,提出了估算消费者的营养级的新模型并进行了相应计算,最终构建了江苏滨海湿地简化食物网模型。主要结论:(1)主要初级生产者的δ13C介于-28.856×10-3与-10.952×10-3之间,δ15N介于1.219×10-3与6.496×10-3之间,均具有显著差异,消费者个体的δ13C介于-27.564×10-3与-11.641×10-3之间,δ15N介于4.462×10-3至10.339×10-3之间;(2) 研究区生态系统可以划分成潮间带和潮上带两个亚生态系统,其中潮上带的主要食物源为芦苇,潮间带的主要食物源为互花米草及微体藻类,盐蒿对两个亚生态系统都有一定的食物贡献率,但均不高。(3)研究区的大型底栖生物及草食性哺乳类大部分占据第二营养级;(4) 研究区动物可以划分为8个主要功能类群,即植食性哺乳类、植食性昆虫、鸟类、淡水游泳类、咸水鱼类、底内动物、底上动物以及浮游动物。总之,潮间带动物比潮上带动物的食物组成多样性略高,与研究区域的生物多样性基本吻合。另外,潮间带生物的食物竞争十分激烈,光滩上分布有一定重叠的优势种并存在一定的食物生态位分化。 相似文献
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绥中30-3构造区油气勘探的主要目的层是古近系沙河街组二、三段,属近岸湖底扇相,其近岸湖底扇砂岩具有较好的成藏条件.针对断裂系统复杂和沉积相带变化快导致地层对比、储层预测难度大的特点,在精细井震标定、子波提取,构造解释基础上,建立初始波阻抗模型,运用Jason6.2软件进行约束稀疏脉冲拟波阻抗反演.在反演拟波阻抗数据体上,分别提取了沙二段3套砂体波阻抗平面分布图,预测绥中30-3构造中南部为有利目标区,并提出了井位建议,对油田的进一步勘探开发具有一定的指导意义. 相似文献
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苏北沿海,一般把建国后筑海堤匡围的110多个垦区称为新垦区。在这275万亩新垦区中,除进行农林牧渔盐等利用了207万亩以外,有68万亩没有开发。近期在潮上带还可新围100多万亩。新垦区的挡潮除渍、蓄水排涝等都离不开水利工程,建设好必需的水利设施往往能有效地促进垦区的生产和经济发展,加快土地资源的综合开发速度。 相似文献
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射阳河口互花米草入侵对大型底栖动物群落的影响 总被引：1，自引：0，他引：1
2008年11月至2009年10月,在盐城自然保护区射阳河口滩涂分别于潮间带、潮上带和潮沟中设置互花米草区与非米草区2类对照样地(共6类生境),按月份取样来研究大型底栖动物群落特征的差异,探讨互花米草入侵对底栖动物的影响。共发现大型底栖动物22种,隶属3门4纲17科,其中软体动物13种,节肢动物6种,环节动物3种。米草区和非米草区的物种组成不同,各生境在不同月份大型底栖动物的物种数、密度、生物量和Shannon-Wiener多样性指数均在不断波动,在潮间带上述指标均为In>Ig,潮上带除密度外均为Sn>Sg,潮沟边滩除个别月份外均为Cg>Cn;3类互花米草生境中大型底栖动物群落各项指标月间变动趋势基本一致(仅个别月份例外),均表现为Cg>Sg>Ig,互花米草生境存在共同的优势种,但数量有一定的差异。分别对潮间带、潮上带和潮沟中互花米草区与非米草区2类对照样地的物种数、密度、生物量以及Shannon-Weiner多样性指数H’进行生境-月份间无重复双因素方差分析,结果显示潮间带2类对照样地各项指标在生境间差异均极显著,月份间差异均不显著;潮上带2类对照样地各项指标生境间存在极其显著的差异(除密度外),月份间差异显著(除多样性外);潮沟2类对照样地生境间差异显著(除生物量外),月份间差异均显著。研究结果表明不同生境中的互花米草对底栖动物的影响不甚相同:潮间带互花米草的入侵降低了大型底栖动物的物种数、密度、生物量和多样性;潮沟米草的入侵提高了大型底栖动物的物种数、密度和多样性;而潮上带米草入侵对大型底栖动物的各指标影响不一。 相似文献
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海洋Sensor Web(传感器万维网)的研究与开发,对于海洋信息的实时获取、系统集成和高效共享具有重要作用。对Sensor Web的国内外研究现状进行综述,介绍Sensor Web的体系结构和集成标准,并对海洋Sensor Web的研究与开发面临的问题进行分析,对海洋Sensor Web未来的发展方向进行探讨。 相似文献
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海洋石油降解菌剂在大连溢油污染岸滩修复中的应用研究 总被引：2，自引：0，他引：2
对海洋石油降解菌群DC10的降解特性进行了研究,研制了基于该菌群的降解菌剂,并用于大连实际溢油岸滩生物修复实验,考察了降解菌剂对潮间带和潮上带油污的降解作用,通过分析C17/藿烷、C18/藿烷及总烷烃和总芳烃的降解率来评价其降解效果。降解菌群DC10在实验室条件下对石油的降解率高于各组成菌株,一周时间的石油降解率比对照提高了60%左右,能降解大部分的烷烃和芳烃。以DC10冻干菌粉辅以营养盐溶液研制降解菌剂,该菌剂在大连岸滩油污生物修复试验中显示出显著的降解效果。在为期12 d的潮间带油污生物修复试验中,喷洒菌剂处理的C17/藿烷和C18/藿烷降解率相对于自然风化处理分别提高了40%和30%,而总烷烃和总芳烃降解率分别提高了80%和72%。在为期85 d的潮上带油污生物修复试验中,从C17/藿烷和C18/藿烷的降解率来看,喷洒菌剂处理对油污的降解程度仅略高于自然风化,但总烷烃和总芳烃的降解率分别提高了近30%和20%。 相似文献
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《Estuarine, Coastal and Shelf Science》2006,66(1-2):197-203
Coarse woody debris (CWD) in the intertidal region of rocky shores serves as a potential source of nutrients as well as habitat or refugia from predation, ecologically linking the adjacent marine and terrestrial habitats. In a series of field and laboratory experiments, the affinity of slow-moving motile intertidal gastropods to CWD either as food source or as shelter that increases habitat complexity was tested. In intertidal pools, CWD did not increase colonization by Littorina spp., while it did so in supratidal pools. Habitat complexity, brought about by algal cover and barnacles, was apparently sufficient in intertidal pools without woody debris, while the increase in habitat complexity by CWD increased the attractiveness of supratidal pools with little natural complexity to Littorina spp. Overall, however, comparison of pools containing woody debris and those containing artificial shelter provided evidence for CWD, and/or its biofilm, serving as food source rather than refugium per se. Similarly, Tegula funebralis chose CWD as food source rather than as shelter as indicated by comparison of autoclaved and unmanipulated woody debris. Further, both unfed and fed snails from a site where CWD was present significantly preferred CWD over macroalgae. Among snails from a site without woody debris, fed individuals showed no preference, while unfed snails significantly preferred macroalgae. From this, experience appears to be a factor that mediates the role of CWD. Overall, however, CWD appears to provide supplementary food to snails in the inter- and supratidal zone. 相似文献
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以山东半岛北部为研究区,以烟台、蓬莱、龙口和莱州4个港口的潮情为依据,分别选取1984、1995、2005、2010、2015年的Landsat系列遥感影像,分析了山东半岛北部滩涂(含潮上及潮间带)及海岸线30a来的变化.研究结果表明:(1)研究区近30a来滩涂面积减少300.66 km2,其中潮间带面积减少了84.84 km2,潮上带面积年减少了215.82 km2,减少区域主要集中在莱州湾东南部;(2)海岸线长度呈递增趋势,30a来增加103.68 km,增长速度为3.34 km/a,增加典型区集中在莱州太平湾、龙口人工岛群、蓬莱港和烟台港等区域;(3)通过实地调研发现,盐田、养殖池的大量扩建、海岸侵蚀和入海泥沙量减少是滩涂减少的主要原因;沿海养殖池的增加和填海造陆的扩张是海岸线长度增加的主要原因. 相似文献
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《Marine Geology》2001,172(3-4):205-223
A mathematical wave erosional model was used to study the effect of high sea levels during the penultimate (oxygen isotopic stage 7) and last interglacials (substage 5e), and in the late Holocene (stage 1), on the present morphology of wave-cut shore platforms. Sea level was considered to have been either the same as today or 2.25 m lower during the penultimate interglacial, and 2.25, 4.5 or 6.75 m higher than today during the last interglacial stage. The model suggested that inherited, gently sloping shore platforms in resistant rocks may be essentially protected today from erosion by high storm waves. The lowest platform gradients were in runs with mesotidal (3 m) range, and usually with low wave periods, low surf attenuation rates and weak rocks. Modern platform gradients increased with the difference in elevation between sea levels during successive interglacial stages. Shore platforms were widest in runs in which sea level was the same as today in the penultimate interglacial and 4.5 m higher than today during the last interglacial. Constant sea level, and high, last interglacial sea levels with considerable overlapping between the zones of high duration values between the mean neap high and low tidal levels in stages 7, 5e and 1, were conducive to the development of wide shore platforms, whereas sea levels lower than today's in stage 7 tended to produce narrower platforms. In general, higher sea levels during the last interglacial tended to produce higher cliff–platform junctions than constant sea level, unless the sea was lower than today during the penultimate interglacial stage. There was a lack of supratidal ledges in macrotidal (9 m) model runs with high initial gradients; this suggests that gently sloping, inherited shore platforms are essential for the subsequent development of supratidal, nonstructural ledges in high tidal environments during periods of higher sea level. Intertidal ledges developed in the upper portion of the modern intertidal zone, under a variety of tidal and sea level conditions. These ledges can develop independently of lithological or structural influences, and without any change in sea level. A single high sea level may also simultaneously produce two ledges at different supratidal elevations in mesotidal environments. 相似文献
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《Marine environmental research》1986,19(1):49-76
The weathering of a very light crude oil (a condensate) in a sandy beach in Nova Scotia has been studied by following changes in its detailed chemical composition.Evaporation was the dominant weathering process in supratidal sand. After 4 months all oil components more volatile than n-C16 had disappeared; concentrations of compounds less volatile than n-C18 did not change. In the surface sand of the upper intertidal zone evaporation was much slower, with C8 hydrocarbons still present after 3 months. Dissolution was also important in this environment with aromatic components up to the C1-naphthalenes being removed in the first month. In subsurface (5–10 cm) sand from this zone and in both surface and subsurface samples from the middle intertidal zone, no loss of volatiles occurred over a 6-month period. Preferential Dissolution was significant in these environments, but was neither as rapid nor as extensive as in the surface sand of the upper intertidal zone. Observed dissolution rates were at least ten times slower than those predicted using equilibrium solubilities and pore water exchange rates.The mobility of the condensate through beach sand was dependent on the oil/sand ratio. At low concentrations, bulk oil movement was insignificant, but, at higher concentrations, movement was rapid, independent of interstitial water flow and exclusively upwards. Only at higher concentrations was appreciable oil free in the sand interstices where it was subject to this buoyancy transport mechanism. 相似文献
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It is known that the fauna of the exposed sandy beaches are primarily controlled by physical variables; but how these variables operate along and across the beach still remains fairly under discussion. In our study, we sampled a range of exposed sandy beaches along the Northwest coast of Spain to determine the relationship between the principal physical variables of the beaches (including beach morphodynamic state), and the macrofaunal community. The fauna of these beaches comprise truly marine species along the intertidal zone as well as semi-terrestrial species in the upper and supratidal environments. These two groups respond in a different manner to the physical environment. The first group is directly controlled by the morphodynamic state of the beach, and variations in the physical environment; the second group is not clearly affected by these physical conditions. In this case, other variables such as food availability and the human uses of the upper limits of the beach seem to be more relevant in explaining the patterns observed in the macrofaunal community. 相似文献