遥感时间序列影像变化检测研究进展   总被引：2，自引：0，他引：2  

赵忠明  孟瑜  岳安志  黄青青  孔赟珑  袁媛  刘晓奕  林蕾  张蒙蒙 《遥感学报》2016,20(5):1110-1125

同一区域、不同时期大量历史数据的积累,以及同一区域能够方便地获取高时间分辨率遥感数据,使遥感时间序列影像变化检测成为近年来遥感技术与应用的研究热点。本文系统总结和评述了当前遥感时间序列影像变化检测的相关研究进展和应用状况,在阐明遥感时间序列分析的意义,以及时间序列影像在变化检测中的优势的基础上,从非遥感领域时间序列变化检测方法出发,针对遥感时间序列影像变化检测的需求,明确和归纳了遥感时间序列变化检测的问题与类型,并对当前最新研究进行了综述,总结了各种方法的优点与不足,重点介绍了基于经验模态分解的遥感时间序列影像异常信息检测方法和基于隐马尔可夫模型的土地利用/覆盖变化检测方法,以期能够为相关研究提供参考。最后总结了该研究领域的发展趋势和存在问题,并对今后的研究工作和未来发展方向进行了展望。  相似文献   

Satellite-Based Assessment of the Extent and Changes in the Mangrove Ecosystem of the Niger Delta   总被引：1，自引：0，他引：1  

Godstime K. James  Jimmy O. Adegoke  Ekechukwu Saba  Peter Nwilo  Joseph Akinyede 《Marine Geodesy》2007,30(3):249-267

This study was carried out with the primary aim of understanding how the mangrove ecosystem in the Niger Delta has been altered recently. Specifically, we determined the spatial extent of the mangrove forest in the Niger Delta using remotely sensed satellite data and estimated changes in the spatial extent of the forest from the mid-1980s through 2003. Overall, about 21,340 hectares of Mangrove forest was lost over the study period. Fieldwork confirmed that these losses were primarily due to urbanization, dredging activities, activities of the oil and gas industries, and the spread of Nypa Palm (Nypa frutican) plant species.  相似文献   

Habitat use by the European eel Anguilla anguilla in Irish waters   总被引：2，自引：0，他引：2  

T. Arai  A. Kotake  T.K. McCarthy 《Estuarine, Coastal and Shelf Science》2006,67(4):569-578

The apparent use of marine and freshwater habitats by European eel Anguilla anguilla was examined by analyzing the strontium (Sr) and calcium (Ca) concentrations in otoliths of the eels collected from Irish coastal and fresh waters. The age and growth of eels were also examined using their otolith annuli. The sizes and ages of the female eels were greater than those of the males. The somatic growth rates ranged from 15 to 62 mm/year, which is typical for Ireland and other European countries. Analyses of Sr:Ca ratios along a life history transect in each otolith showed peaks (maximum more than 25 × 10⁻³) between the core and elver mark corresponding to the period of their leptocephalus and early glass eel stages in the ocean. Outside the elver mark, the Sr:Ca ratios indicated that eels had remained in different habitats that included freshwater (average Sr:Ca ratios, 0.98–1.78 × 10⁻³) and areas with relatively high salinities (average Sr:Ca ratios, 6.73–8.89 × 10⁻³). Some individuals showed clear evidence of shifts from sea to fresh waters. These findings suggest that Irish eels have the same behavioral plasticity regarding whether or not to enter freshwater or remain in marine environments as has been recently documented in this species and several other temperate anguillid species. However, patterns of habitat use in Irish waters were somewhat different than those previously reported for other habitats.  相似文献   

Preface: land-use impacts on aquatic ecosystems - tribute to John Quinn     

Scott Larned  Kevin Collier  Clive Howard-Williams 《新西兰海洋与淡水研究杂志》2020,54(3):305-307

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Characteristics of Habitats Used by
Enteroctopus dofleini in Prince William Sound and Cook Inlet,Alaska     

David Scheel 《Marine Ecology》2002,23(3):185-206

Abstract. Habitat characteristics associated with the giant Pacific octopus, Enteroctopus dofleini (Wülker 1910), were studied in Prince William Sound and Port Graham, Alaska, from beach walk, SCUBA and submersible surveys at depths of 0 to 197 m. Octopus counts on beach walk transects were positively correlated with soft substrates (sand, gravel or broken rubble), the presence of boulders, and dense kelp cover immediately offshore of the transect; and negatively correlated with depth on SCUBA transects. No significant habitat correlations were found with counts on submersible transects. On beach walks, octopus counts were reduced on hard substrates to 38 % of the counts on soft substrates. Counts increased five‐fold in the presence of boulders over counts in their absence, and increased fifteen‐fold adjacent to dense (> 75 %) kelp cover over counts adjacent to sparse (< 25 %) kelp cover. On SCUBA transects, the average density at less than 5 m depth was over five times that below 5 m. No trends in octopus size or sex ratio were detected with depth. Den use was inversely correlated with depth although there was no indication that den availability declined with depth. Octopuses were found at densities from 0 to 2.5 per 1000 m². These densities were only 1 to 50 % of densities of the same species recorded in British Columbia in the late 1970s and early 1980s. Few data are available to test recruitment, mortality, and habitat selection hypotheses that would account for differences between habitats. However, the presence of the highest octopus densities in intertidal and very shallow subtidal areas indicates the likely importance of near‐shore, shallow‐water habitats, and highlights the vulnerability of octopus populations to changes in these habitats.  相似文献   

关于长山群岛土地利用总体规划的编制          下载免费PDF全文

张耀光  胡宜鸣 《海洋开发与管理》1994,11(3):21-26

对海岛土地利用的目的，依据、过程以及编制海岛土地利用总体规划的有关问题进行了分析和论述。  相似文献   

Resource use conflicts in Mabini and Tingloy,the Philippines     

Terhi Majanen 《Marine Policy》2007

This paper presents the results of an analysis of resource use conflicts in areas near marine protected areas in Mabini–Tingloy, the Philippines. The author found large differences between groups of stakeholders in terms of perceived benefits and costs of conservation and tourism, and these inequalities have led to conflicts between various stakeholder groups. Marked by unequal power relationships, the conflicts place subsistence fishers as the weakest stakeholders. Fishers also have the lowest rates of knowledge of and participation in conservation activities. The study concludes that in order for conservation programs to be effectively transitioned onto the social and legal fabric of Mabini–Tingloy, resource use conflicts need immediate attention.  相似文献   

福建海洋资源开发利用及其对策   总被引：3，自引：1，他引：3  

黄发明 《台湾海峡》2001,20(4):490-495

本文分析了福建省开发海洋资源的优势、现状和存在问题，结合可持续发展观点为，提出了福建海洋资源永续利用的对策。  相似文献   

基于Landsat-8 的湛江东海岛地物分类研究     

《海洋技术学报》2024,(1)

“宝钢湛江项目”的实施对近十年湛江东海岛的地物分布产生剧烈影响，尤其是工业用地。本文基于2013 年、2017 年和2021 年的陆地卫星8 号（Landsat-8） 数据对湛江东海岛进行地物分类，研究该区域近十年的用地变化趋势。以2013 年数据为参照：采用归一化水体指数（Normalized Difference Water Index，NDWI） 模型和谱间关系模型实现水陆分离，比对选择分离效果较优者以提取东海岛岸线；对比最大似然法、神经网络法和支持向量机法3 种监督分类方法，选择提取地物效果最优者应用于其余数据。基于Google earth 在线地图及无人机实测数据构建验证点集，使用混淆矩阵进行精度评价。结果表明：谱间关系模型的水陆分离效果较优，提取海岛岸线的精确度有明显提升；支持向量机法的分类总体精度和Kappa 系数最高，分类结果能较好地反映研究区的真实地物分布；汇总三年数据的分类结果，发现用于发展工业的土地面积增长突出且处于持续增长趋势。谱间关系模型与支持向量机法分别实现了对东海岛岸线和地物类型的准确提取，得出近十年研究区的用地变化趋势，能为研究区的用地规划提供参考。  相似文献   

Organic carbon transport in the Songhua River,NE China: Influence of land use          下载免费PDF全文

Huiguo Sun  Jingtai Han  Dongwei Li  Xixi Lu  Haibo Zhang  Wei Zhao 《水文研究》2017,31(11):2062-2075

Carbon transported by rivers is an important component of the global carbon cycle. Here, we report on organic carbon transport along the third largest river in China, the Songhua River, and its major tributaries. Water samples were collected seasonally or more frequently to determine dissolved organic carbon (DOC) and particulate organic carbon (POC) concentrations and C/N and stable carbon isotopic ratios. Principal component analysis and multiple regression analysis of these data, in combination with hydrological records for the past 50 years, were used to determine the major factors influencing the riverine carbon fluxes. Results indicate that the organic carbon in the Songhua River basin is derived mainly from terrestrial sources. In the 2008–2009 hydrological year, the mean concentrations of DOC and POC were 5.87 and 2.36 mg/L, and the estimated fluxes of the DOC and POC were 0.30 and 0.14 t·km^?2·year^?1, respectively. The riverine POC and DOC concentrations were higher in subcatchments with more cropland, but the area‐specific fluxes were lower, owing to decreased discharge. We found that hydrological characteristics and land‐use type (whether forest or cropland) were the most important factors influencing carbon transport in this system. Agricultural activity, particularly irrigation, is the principal cause of changes in water discharge and carbon export. Over the last 50 years, the conversion of forest to cropland has reduced riverine carbon exports mainly through an associated decrease in discharge following increased extraction of water for irrigation.  相似文献