基于滩涂围垦的海岛城市时空扩张特征研究——以舟山本岛为例          下载免费PDF全文

羊大方  李伟芳  马仁锋  杨晓平  夏然  朱菲菲  袁敏杰  尹昌霞 《海洋学研究》2017,35(2):61-73

以舟山本岛为研究单元,利用1995年,2005年和2015年的遥感影像,采用生态学分析、空间统计学分析、城市扩张指数等方法来探究舟山本岛滩涂围垦活动和城市用地扩张的特点,并分析两者之间的关联。结果表明:(1)在1995—2015年的20 a间,滩涂围垦的面积不断扩大。(2)1995—2005年的滩涂资源利用以近陆域的海涂为主,2005—2015年逐渐向浅海发展。(3)1995—2015年间,城市用地面积前10 a增长强度为0.53,增长速度为3.01 km²/a,后10 a增长强度为1.46,增长速度为8.11 km²/a。(4)舟山本岛的城市发展重心在20 a间经历了一个自西向东移动而后向北跳跃的过程,各区域间协同发展,使舟山本岛经济整体性和城市功能合理性得到提升。(5)滩涂围垦形成的土地与城市用地扩张之间存在着正相关关系,且从研究数据来看两者之间发生自然演替需要时间,大约为8~10 a,人工干预可以大幅缩短这个过程所需要的时间。  相似文献   

舟山海域风暴潮特征及数值模拟研究     

杨昀  王惠群  管卫兵  曹振轶  陈琪 《海洋学研究》2015,33(3):7-16

选择20个对舟山海域有较大影响的历史台风案例,开展定海站实测潮位数据的分析与归纳,总结得出20个台风中风暴潮过程增水最大值为5612号台风的207.1 cm,风暴潮高潮位最大值为9711号台风的283.7 cm。同时,在三维斜压水动力模型SELFE的基础上加入台风气压场和风场模块,建立了一个采用非结构三角形网格的天文潮-风暴潮耦合模型,模拟表明定海站的斜压效应较为明显,非线性耦合作用相对较弱,但两潮耦合风暴潮增水结果仍优于风暴潮单因子增水结果,与实际增水更为接近。在此基础上,以一定间隔在5612号台风原路径南北两侧各设计了2条平行路径,分别模拟两潮耦合风暴潮增水,结果表明5612号台风参数沿其原路径偏南1个最大风速半径距离的S1路径运动时可模拟得到定海站可能最大风暴潮增水为243.9 cm。最后,在S1路径下模拟可能最大风暴潮增水分别遭遇天文高、中、低潮位时的风暴潮高潮位,结果表明天文潮高潮时可得到可能最大风暴潮高潮位约为400 cm,天文中潮时次之,而天文低潮时风暴潮高潮位最低。  相似文献   

Geochemical evidence concerning sources and petrologic evolution of Faial Island,Central Azores     

《International Geology Review》2012,54(14):1684-1708

Volcanic rocks that make up Faial Island, Central Azores, consist of four volcano-stratigraphic units, with ages between 730 ka and the present. Lavas range from alkali basalts to trachyandesites and belong to the alkaline-sodic series. The oldest unit is the Ribeirinha Volcanic Complex, generally characterized by low MgO contents. The Cedros Volcanic Complex is composed of basalts to benmoreites with low MgO contents. The Almoxarife Formation represents fissure flows, containing MgO contents similar to to slightly higher than those of the underlying Cedros Volcanic Complex. The youngest unit, the Capelo Formation, consists of mafic rocks with MgO values higher than those of the other units. Bulk-rock major and trace element trends suggest that differentiation of the three earliest units were dominated by fractional crystallization of plagioclase ± clinopyroxene ± olivine ± titanomagnetite. Capelo bulk-rock compositions are the most primitive, and are related to a period when volcanic activity was fed by deep magmatic chambers, and melts ascended more rapidly. Comparison among geochemical patterns of the trace elements suggests a strong similarity between the lavas from Faial and Pico islands. Corvo Island volcanism contrasts with the geochemistry of Faial and Pico lavas, reflecting its strong K and Rb depletion, and Th, U, Ta, Nb, La, and Ce enrichment. Absence of the Daly gap in the Faial volcanics is attributed to early crystallization of Ti-Fe oxides. The probable source of the Faial magma coincides with the MORB-FOZO array, which implies the presence of ancient recycled oceanic crust in the mantle source. Ratios of incompatible trace elements suggest the similarity of Corvo volcanic rocks with magmas derived from HIMU sources, whereas the Faial and Pico volcanic rocks could have been produced from sources very close to EMII-type OIB.  相似文献   

舟山近岸海域表层沉积物中5种重金属元素的污染及潜在生态风险评价   总被引：7，自引：1，他引：6  

蒋红  胡益峰  徐灵燕  李卫丁 《海洋学研究》2011,29(1):56-61

利用2006年8月采集于舟山本岛南部近岸海域的表层沉积物监测数据,采用Hakanson生态风险指数法,分析了Hg、As、Pb、Cd和Cu等5种重金属元素含量,并进行了潜在生态风险评价,结果表明:舟山近岸海域表层沉积物中Hg、As、Pb和Cd元素的含量均符合国家海洋沉积物质量一类标准;各重金属元素均为低污染水平,潜在生态...  相似文献   

舟山本岛南部附近海域潮汐潮流特征分析          下载免费PDF全文

李卫丁  王燕妮 《海洋开发与管理》2019,36(3):64-68

文章基于沈家门长期潮位站、长峙岛临时潮位站的观测资料和对舟山本岛南部海域多个站位实测的潮流基础数据,采用调和分析法对潮汐潮流进行特征分析。舟山本岛南部附近海域潮汐类型属于规则半日潮,潮差变化和日不等现象明显,有一定的潮汐浅海作用。潮流类型属于以往复流为主的规则半日浅海潮流,实测潮流中涨落潮流速不等、历时不等现象显著,最大流速、平均流速均是大潮大于小潮,涨潮流历时长于落潮流历时,潮流变化主要受协振波所控制,流向在涨落潮方向波动。  相似文献   

舟山鱼类油脂中饱和及不饱和脂肪酸组成的初步研究   总被引：7，自引：0，他引：7  

叶新荣  吴亚平 《海洋科学》1990,14(3):40-43

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等边浅蛤Gomphina veneriformis的繁殖周期     

尤仲杰  王一农 《台湾海峡》1991,10(4):356-363

本文根据1987.12～1989.4对舟山朱家尖岛南沙沙滩逐月采集标本进行研究。结果表明,等边浅蛤Gomphina veneriformis的性腺发育可分为5期:增殖期、生长期、成熟期、排放期和休止期。在舟山海区,等边浅蛤一年中为一个繁殖周期,繁殖期为8月下旬至9月中旬。有雄性早熟现象。  相似文献   

Water exchange of the Stockholm archipelago—a cascade framework modelling approach     

Anders Engqvist  Oleg Andrejev 《Journal of Sea Research》2003,49(4):275

The Stockholm archipelago spans roughly a semicircular area with a radius of approximately 60 km, traditionally partitioned into three parts: the inner, the middle and the outer archipelago. This subdivision coincides with differing water exchange regimes. The inner and middle archipelagos are characterised by comparatively larger basins which are interconnected by a limited number of straits. This configuration is well suited for a discrete basin (DB-) model approach by partitioning the area into a set of sub-basins that are only resolved vertically. The advantage of this approach over 3D-models is the possibility for enhanced vertical resolution and improved strait exchange formulation, outweighing the disadvantage of neglected horizontal gradients within the basins. In the inner archipelago the dominating exchange process is estuarine circulation, induced by the marked freshwater discharge and the vertical mixing. In the outer and middle archipelagos the density fluctuations due to Ekman pumping along the Baltic boundary interface produce another type of baroclinic process that clearly dominates. Measurements to adequately resolve these density variations do not exist. Missing forcing data are provided by linking the middle archipelago's boundary straits to a 3D-model of the Baltic with a grid resolution of 0.5 nautical miles (n.m.). This fine resolution model (FR-domain) is in turn driven by the atmospheric forcing and the density variation at the rectangular boundary of the FR-domain which acceptably resolves both the interfacial straits and the outer archipelago's complex hypsography. Massive computing resources would be demanded if the FR-domain were extended to comprise the entire Baltic. The FR-domain is thus interfaced with an existing coarse resolution model of the entire Baltic (CR-domain) with a grid size of 5 n.m., the open boundary of which is located in the Kattegat. This 3-fold model set-up has been run for one whole year (1992) with a one-year spin-up time to make up for the lack of initial data. The model concept is at this stage to be regarded as a framework for further development in anticipation of improved formulations, particularly for the strait exchange formulation. Therefore only primary validation experiments and a few sensitivity analyses have been performed.  相似文献   

舟山渔场及其邻近海域水团的气候学分析   总被引：23，自引：1，他引：23  

张启龙  王凡 《海洋与湖沼》2004,35(1):48-54

根据多年(1958—1990)月平均温、盐度资料，采用模糊聚类分析法划分了舟山渔场及其邻近海域的水团，并对该海域水团的配置、主要特性及其季节变异特征进行了气候学分析。结果表明，舟山渔场及其邻近海域共存在4个水团，即江浙沿岸水、台湾暖流表层水、台湾暖流深层水和黄海混合水；全年水团的配置可归纳为冬季型、夏季型和过渡型3种类型；江浙沿岸水的主要特征为低盐，其分布范围和盐度的季节变化与长江入海径流密切相关，而温度的季节变化则主要受太阳辐射的影响；台湾暖流表层水具有高温、次高盐特征，其北伸程度和温、盐特性均具有明显的季节变化，即冬季北伸强、温度低、盐度高，夏季北伸弱、温度高、盐度低；台湾暖流深层水以低温、高盐为主要特征，仅存在于4—9月，其温、盐性质较稳定；黄海混合水的主体不在研究海域。  相似文献   

舟山近海环境DNA保存方法的建立及优化   总被引：1，自引：0，他引：1  

陈治  陈建威  王晓艳  高天翔  刘岩 《海洋与湖沼》2019,50(5):1098-1107

近年来,环境DNA(environmentalDNA,eDNA)技术开始被广泛应用于水生生物多样性研究。本文通过绝对定量和高通量测序技术对舟山近海高浊度水样eDNA的保存方法进行了建立和优化。研究结果如下:(1)"酒精+低温"保存法的eDNA获得量是"酒精+常温"保存法的0.78—1.06 (7d)、0.89—1.80 (15d)、1.05—2.75 (30d)和2.69 (60d)倍;(2)酒精保存法(低温、常温)存在eDNA富集物渗漏及滤膜黏附现象;(3)短期内冷冻保存样品的eDNA获得量是酒精保存样品获得量的1.25—1.59倍(7d)和1.07—1.20倍(15d);(4)酒精保存法的eDNA降解速率慢于冷冻保存法,长期内酒精保存样品的eDNA获得量是冷冻保存样品获得量的1.99—2.10倍(30d)和2.84—7.64倍(60d);(5)二次富集(过滤)能显著提高eDNA获得量,富集组eDNA浓度是未富集组浓度的1.60—4.95倍("酒精+低温")和1.21—2.04倍("酒精+常温");(6)"酒精+低温"保存的样品在高通量测序总丰度、各鱼种分丰度、物种多样性指数等多个方面优于冷冻保存样品;(7)微生物(micro-organism)的eDNA降解速率慢于大生物(macro-organism),不同界(Kingdom)的eDNA最优保存方法可能并不相同。本研究首次建立了舟山近海高浊度水样eDNA最适保存方法,为相似水域的eDNA保存提供了借鉴参考。  相似文献