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1.
图们江是我国重要的国际性河流之一,受中国、朝鲜、俄罗斯三国政策、经济、文化等因素影响,三国的湿地景观截然不同。本文以我国国产高分辨率卫星GF-1和GF-2影像为数据源,通过对图们江口湿地的实地踏勘,建立了图们江口湿地遥感分类体系,包括湖泊、河流、沼泽、滩涂、坑塘、水田和水库共7类。采用目视解译方法,提取了图们江口湿地信息,对图们江口湿地现状和中、朝、俄湿地差异进行了分析。利用Fragstats景观分析软件,选取了斑块数(NP)、最大斑块指数(LPI)、斑块平均面积(MPS)、加权平均形状指数(SHAPE)、加权平均分形维数(FRAC)、香农多样性指数(SHDI)和香农均匀性指数(SHEI)等几个景观格局指数分析了图们江口湿地景观格局特征。结果表明:(1)研究区湿地总面积为39 503.38 hm2,以沼泽和湖泊为主,呈现近日本海聚集分布格局。(2)俄罗斯湿地面积占各国研究区湿地总面积比例最大,朝鲜次之,中国最小;朝鲜湿地开发程度最高,湿地破坏较严重。(3)朝鲜湿地破碎程度在三国中最重,中国次之;朝鲜因水田开发较严重,景观规则度最高;中国湿地多样性较其他两国丰富。 相似文献
2.
对海岸带国土空间开发利用演变进行研究,有助于为海岸带陆海统筹与可持续发展提供新的思路与支撑。基于温州市海岸带多时相土地利用数据、遥感影像数据和综合海域使用数据,从陆域系统的景观格局与土地开发利用程度、海域系统的使用结构与多样性、大陆海岸线变迁三个角度研究温州市海岸带国土空间开发利用特征的时空变化特征。结果表明：（1） 1990-2018年温州市海岸带陆域系统景观动态变化显著,林地、耕地、城乡工矿居民用地和水域的面积变化幅度较大,主要表现为1995年前耕地转变为林地,1995年后其他景观转变为城乡工矿居民用地;（2） 1990-2018年温州市海岸带陆域系统景观空间格局整体上呈现破碎化趋势,但在2015年后情况有所好转;（3） 1990-2018年温州市海岸带开发利用程度总体呈现不断增强趋势,陆域系统和海域系统的开发利用结构趋于均衡化和多元化,大陆海岸线趋于平直并向海侧推移。 相似文献
3.
山东省淡水枝角类的初步调查 总被引：4，自引：0，他引：4
山东省淡水水域广阔,不仅河流多,而且湖泊、水库、坑塘星罗棋市,资源丰富。其中的淡水枝角类是水体食物链之重要环节,对渔业主产和环境保护工作具有相当重要的现实的意义。因此,必须对其更好地调查研究如培育利用。笔者多年来,就山东省若干地区的淡水枝角类进行采集、分类等研究工作。本文报道其初步结果——隶属7科,24属,71种。 相似文献
4.
文章以深圳湾海岸带为研究对象,在遥感和GIS技术的支持下,应用2001年和2009年遥感影像解译信息,建立空间信息库并叠加分析,获取景观类型动态转移数据矩阵,得出2001-2009年深圳湾海岸带景观空间分布规律及其变化特征,即红树林、建设用地和河流的面积有所扩张,湖泊、滩涂沙洲、林地、浅海水域和绿地的面积有所减少。同时,应用马尔科夫模型对海岸带景观格局的变化趋势进行预测,得出浅海水域、滩涂沙洲、湖泊、林地和绿地的比重将继续下降,建设用地和红树林的比重将持续上升,河流的比重基本不变的结论。由此提出深圳湾应加强对填海造地工程的规划,保护海洋生态环境,实现科学用海和生态用海。 相似文献
5.
为了了解子牙河流域湿地的动态变化特征,本文使用2000、2004、2009和2014年间4景Landsat TM/ETM+/OLI夏季遥感影像,通过目视解译、改进的归一化差异水体指数、归一化植被指数、景观格局指数对湿地面积、水域、植被和景观格局变化等方面进行了研究。研究结果表明:2000、2004、2009、2014年间,子牙河流域湿地面积分别为1 861.99、1 890.42、1 823.19和1 885.43km~2;湿地水面面积分别为为463.14、629.74、562.69和796.69km~2;湿地植被面积分别为1 025.22、936.55、1 058.76和764.34km~2。景观格局指数方面,斑块密度(PD)逐年增加,最大斑块指数(LPI)在8.16~8.46之间;周长面积分维数(PAFRAC)基本处于1.46左右;香浓多样性指数(SHDI)随时间上升,香浓均匀度指数(SHEI)逐年提高。结果表明:湿地面积总体呈增加趋势,但增加的湿地面积主要是人工湿地,自然湿地面积还需要继续恢复;湿地水域主要分布在研究区域的东部和西部,中部较为缺水;湿地植被面积以2009年面积最大,生长状况最好,而到2014年面积、长势有所下降,还需要加强对植被的恢复;研究区域景观越来越破碎化,各类型景观分布越来越均匀,受到人类的干扰越来越大。人们在恢复湿地面积同时,还需要注意防止湿地破碎化,保护自然湿地。 相似文献
6.
《海洋湖沼通报》2020,(3)
以盐城滨海湿地为研究区,根据1997年、2007年和2014年3个时相的遥感影像,运用RS、GIS技术和景观生态学方法,比较不同岸段景观时空动态变化的差异。结果表明:(1)1997～2014年,盐城滨海湿地景观结构变化呈现出非湿地与人工湿地在增加,盐沼在减少的特征。盐沼的面积比重,淤蚀转换岸段淤长岸段侵蚀岸段。景观多样性指数和均匀度指数,淤蚀转换岸段淤长岸段侵蚀岸段;景观聚集度指数,淤长岸段侵蚀岸段淤蚀转换岸段。(2)滨海湿地景观转移表现为盐沼转变为耕地、养殖池和建设用地;盐沼转出的速率,淤长岸段淤蚀转换岸段侵蚀岸段;盐沼转出的比例,淤长岸段侵蚀岸段淤蚀转换岸段。(3)盐城滨海湿地景观转变强度都为负值,说明研究区生态等级在下降;总体景观转变强度,淤长岸段淤蚀转换岸段侵蚀岸段。(4)自然条件与人类活动在时空上的组合差异是盐城滨海湿地景观时空动态区域差异的主要原因。 相似文献
7.
双台河口国家级自然保护区位于辽河下游入海口,该地区湿地发育,区域内土地利用/覆被类型多样。本文基于5个不同时相的Landsat卫星系列TM、ETM和OLI-TIRS遥感影像,采用监督分类法对影像进行分类处理,然后结合GIS空间分析与数理统计方法,分析了1984—2013年期间双台河口国家级自然保护区土地利用/覆被变化情况。结果表明:1984—1992年期间芦苇沼泽和养殖水域大面积增加,天然水域和滩地大面积减少,养殖水域的单一土地利用动态度最大;1992—2000年期间耕地和滩地面积快速增长,天然水域和芦苇沼泽面积快速减少,研究区综合土地利用动态度最大;2000—2007年期间,养殖水域大面积增加;2007—2013年期间,城建用地大面积增加。双台河口自然保护区LUCC受多种因素影响,人口、经济和政策等是主要的社会经济因素,不同时期各社会经济因素对LUCC的推动作用有所差异。 相似文献
8.
长江口滨海湿地景观格局变化及其驱动力分析 总被引：3，自引：0，他引：3
长江口地区是我国经济比较发达的地区之一,滨海湿地为该区的发展提供了大量的后备土地资源和生态资源。通过对长江口地区的实地调查,将该区滨海湿地分为光滩沼泽、潮间沼泽、河口和浅海水域、河流湿地、湖泊湿地5种自然湿地景观,水塘、水田、水库3种人工湿地景观及居民地、建筑用地等非湿地景观类型。在景观分类的基础上,以1986年和1995年的TM影像、2005年的SPOT影像为主要材料,结合其他数据资料,利用相关软件生成了长江口滨海湿地的景观分布图。运用景观生态学原理,选择了景观斑块数(NP)、景观多样性指数(H)、优势度指数(D)、景观形状指数(LSI)等几个生态意义比较明确的景观格局指数来分析研究区景观格局的变化特征,并分析了该区景观格局变化的驱动因素。结果表明:1986~2005年,长江口滨海湿地的面积增加了5.81个百分点;景观斑块数(NP)由1986年的2 213块增加到2005年的2 667块,增加了20.51个百分点;景观多样性指数(H)由1986年的1.730 9上升为2005年的1.876 5;优势度指数(D)自1986年的1.122 7上升为2005年的1.293 4;景观形状指数(LSI)自1986年的44上升为2005年的48。其中面积的增加主要是长江所携带的泥沙在长江口不断淤积的结果,泥沙的淤积同时造成了长江口滨海湿地景观格局的变化,但是目前由于三峡大坝的截流和长江中上游植被面积的增加,长江携带的泥沙明显减少,使得长江口淤积速率有所减慢。上述几个景观指数的变化表示长江口滨海湿地的景观破碎化程度在加剧,景观格局在时间序列上也存在明显差异,调查研究表明,自然驱动力和人为驱动力同时作用于该区景观格局的变化。近20年来,随着经济的发展、人口数量的增加、围垦等活动的加剧,人类活动对研究区的改造导致了自然湿地的面积相对减少,滨海湿地的生态功能不断下降。 相似文献
9.
文章对唐山市沿海地区1991—2015年土地利用和结构变化及其生态系统服务价值进行核算分析和量化评估。结果表明:1991—2015年唐山市海岸带主要地物类型涉及耕地、公路用地、河流水面、建设用地、坑塘水面、盐田、填海用地和裸地,其中坑塘水面占地最多,海岸带开发利用总面积不断增大,用地类型有所转化且向海域扩张,新增用地主要来自围填海且以填海造地为主;海岸带生态系统服务价值呈逐年下降的趋势,以2006—2010年变化最为明显,主要原因为海水面积减少。在充分认识填海造地活动双面性的基础上,建议慎重开展填海造地,集约节约利用海洋空间资源,合理科学规划填海区域,提高海洋资源利用效率。 相似文献
10.
基于“资源三号”卫星的黄河口湿地景观格局及其空间尺度效应分析 总被引：1，自引：0，他引：1
为了在更精细尺度上分析黄河口湿地的景观格局特征,作者基于2012年的国产高分辨率"资源三号"卫星遥感影像,选取斑块类型面积(CA)、斑块个数(NP)、平均斑块面积(AREA_MN)、边缘密度(ED)、平均周长面积比(PARA_MN)、散布与并列指数(IJI)、香农多样性指数(SHDI)和香农均匀度指数(SHEI)8种常用的景观指数,表征景观类型的面积与结构特征、形状特征、聚集特征和景观多样性特征,开展了黄河口湿地的景观格局现状分析,以及空间尺度对黄河口湿地景观格局分析的影响。结果表明:黄河口湿地以裸滩和自然植被等自然景观为主,人工景观所占比重较小,但研究区内油井散布且数量众多,道路修建所导致的景观破碎化已较为明显;总体上,研究区的景观特征具有较强的尺度依赖性,其中表征面积和结构特征的斑块个数、边缘密度、平均斑块面积随着空间尺度的增大有明显的变化,斑块面积则相对稳定,形状特征表现出对空间尺度较强的依赖性,聚集特征随空间尺度的变化不规律,景观多样性特征随空间尺度的变化不明显;不同景观类型的景观特征随空间尺度的变化有较大差异,斑块为条状或斑块边界不规则的景观类型对空间尺度的依赖性更为显著。 相似文献
11.
Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
12.
Derek V. Ellis 《Marine Georesources & Geotechnology》2001,19(1):51-63
This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested. 相似文献
13.
G. Parthiban 《Marine Georesources & Geotechnology》2000,18(3):223-235
Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement. 相似文献
14.
Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
15.
Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
16.
海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
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The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments. 相似文献
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《海洋学报(英文版)》2014,(11):161-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献