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991.
文章根据2006—2016年我国11个沿海省、市、自治区海洋第三产业产值和GDP相关数据,采用变系数模型定量分析了沿海地区海洋第三产业与区域经济发展之间的关系,结果表明:①我国沿海地区海洋经济发展势头良好,并开始由量的增加转变为质的提高,总体海洋产业结构模式表现为三二一模式,海洋主导产业为第三产业。②沿海11个省 、市、自治区海洋第三产业发展对区域经济增长存在促进作用。因此提出优化升级海洋产业结构,积极发展海洋第三产业、提升海洋科技创新水平、构建多元化融资机制等针对性的建议。 相似文献
992.
993.
Indian coastal waters are subjected to considerable pressure from sewage and industrial wastes, which are responsible for
the contamination of the coastal sediments with consequent loss in biosphere. The present investigation attempts to study
the significance of coarse material (Sand fraction) in the distribution of metals in polluted marine sediments. The study
revealed that coarse Sand component contains a relatively significant proportion of the anthropogenic metals (Cd, Cu, Pb and
Zn) and therefore it cannot be neglected in metal pollution studies of coastal sediments. Further, the distribution of anthropogenic
metals in both Silt + Clay and Sand fraction follow the same suit indicating similar pollution sources. From the total sediment
type (Silt + Clay and Sand fraction) all anthropogenic metals had a noticeable amount (>50%) in the acid extractable (and
potentially bio-available) fraction. This article stresses the importance of coarse fraction in metal pollution studies in
Indian coastal system. 相似文献
994.
Understanding a quarry in terms of its potential for breakwater construction materials presents a special challenge for the engineering geologist. Unlike blasting in aggregates and mining operations, optimisation of the extraction process has a focus on the potential for production of large blocks for armourstone. These blocks weighing many tonnes are used for cover layers to resist wave action. The quarry-run is used for breakwater core. If the quarry has been developed as a source of materials dedicated to a breakwater construction project, the success of the project depends greatly on the blasting and production of rock sizes that are required and the avoidance of leaving a massive quantity of unused materials behind in the quarry after project completion. Prediction of in-situ block sizes such as from joint spacing data, provides the most critical input for the prediction of the blast pile block size distribution (BBSD), which in turn is a vital early design input if the constructed breakwater is to be economical as well as effective.This paper is part of a series of papers that introduces the coastal engineering motivation for this work on engineering geology, giving reasons why the prediction of the fragmentation curve of the blast products in a dedicated quarry is of such economic importance for breakwater projects. The first step towards blasted block size distribution (BBSD) prediction is the prediction of the in-situ block sized distribution (IBSD), the main subject of this paper. Drawing together research methods from the 1990s and the rock mechanics principles of discontinuity analysis, a practical step by step methodology for IBSD assessment that includes approaches that are not reliant on specialised computer software is presented. Continuing on the practical theme, a new extension of the volumetric joint count approach is suggested for IBSD prediction for the case when sparse borehole data is all that is available. A case study of IBSD assessment and the associated BBSD and blast assessment is presented from a Carboniferous limestone quarry. For clarity, details of blast design and yield curve prediction that are recommended for use in the context of armourstone production, have been presented in a companion paper. The Rosin-Rammler equation is used as an example form for the BBSD prediction of a dedicated quarry and the potential for breakwater project optimisation is illustrated. The final section sets out a method for directly comparing yield curves together with the demand for materials set by the breakwater design. On the same plot, sizes where there is a relative shortfall in production can be identified. The dependence of effective breakwater design on accurate quarry yield prediction and quarry blasting performance is discussed. 相似文献
995.
J.P. Manning D.J. McGillicuddy Jr. N.R Pettigrew J.H. Churchill L.S. Incze 《Continental Shelf Research》2009
Two-hundred and twenty seven satellite-tracked drifters were deployed in the Gulf of Maine (GoM) from 1988 to 2007, primarily during spring and summer. The archive of tracks includes over 100,000 km logged thus far. Statistics such as transit times, mean velocities, response to wind events, and preferred pathways are compiled for various areas of the coastal GoM. We compare Lagrangian flow with Eulerian estimates from nearby moorings and evaluate drifter trajectories using Ekman theory and 3-D ocean circulation models. 相似文献
996.
Exploring the fringe belt concept in Auckland: An urban morphological idea and planning practice 总被引:1,自引:0,他引:1
Kai Gu 《New Zealand geographer》2010,66(1):44-60
The idea of urban fringe belts has been recognised as a powerful means of understanding the physical form of urban areas and the process of urban outward growth and internal change. Surrounding Auckland's city core, an inner fringe belt can be recognised. Farther out there are middle and outer fringe belts. Fluctuations in socio-economic development, the adoption of new transport modes, land reclamation and topography are major factors influencing the formation of these fringe belts. The examination of changes to fringe belts highlights important issues of urban transformation, which are pertinent to planning and design policies for urban landscape management. 相似文献
997.
对自然和人文景观资源消费与创造行为作为经济学分支或研究方向的必要性及其规律进行探索性、综述性分析,在文献梳理基础上提出景观经济学的内涵、基本问题和研究方法等基本结构框架。景观经济学是研究公众对自然及人文景观偏好形成及演化规律、景观资源消费与创造行为经济规律的社会科学,其基本问题包括景观资源价值评估、景观资源最优利用、景观资源开发与保护政策以及多元景观结构的形成与创造等,其研究方法包括消费者意愿调查法、实验与行为经济学方法、逻辑推理法和个案分析法等。 相似文献
998.
Mid-Holocene coastal hydrology and salinity changes in the east Taihu area of the lower Yangtze wetlands, China 总被引:1,自引:0,他引:1
During the mid-Holocene the eastern Taihu area, on China's Yangtze delta plain, was populated by advanced late Neolithic cultures supported by intensive domesticated rice cultivation. This agricultural system collapsed around 4200 cal yr BP, with severe population decline, the end of the Liangzhu culture, and about half a millennium of very low-scale human activity in the area before the re-establishment of agricultural production. Microfossil analyses from six sedimentary sequences, supported by AMS 14C dating, has allowed reconstruction of mid-Holocene hydrological conditions and salinity changes which would have had a major influence on agricultural viability and cultural history in the coastal wetlands. These data, allied to existing stratigraphic and sea-level records, show that chenier ridges that developed after ca. 7000 cal yr BP in the east of the area sheltered it from marine inundation and, although still connected to the sea through tidal creeks, low-salinity conditions persisted throughout the Neolithic period. There is no evidence that marine flooding caused the collapse of Liangzhu culture. Marine influence was stable and evolved slowly. Social and cultural causes may also have been important, but if environmental change triggered the collapse of Neolithic agricultural society here, other natural forces must be sought to explain this event. 相似文献
999.
A 2-phases neural prediction method for wave overtopping is developed. The ‘classifier’ predicts whether overtopping occurs or not, i.e. q = 0 or q > 0. If the classifier predicts overtopping q > 0, then the ‘quantifier’ is used to determine the mean overtopping discharge. The overtopping database set up within the EC project CLASH (De Rouck, J., Geeraerts, J., 2005. CLASH Final Report, Full Scientific and Technical Report, Ghent University, Belgium) is used to train the networks of the prediction method. 相似文献
1000.
为探究湖北省景观格局变化特征及其驱动因素,本文选取湖北省2000~2018 年5 期土地利用/土地覆被变化(LUCC)数据进行分析,并利用主成分分析法对其驱动因素进行探讨。结果表明:2000~2018 年,湖北省耕地、林地、草地和未利用土地等景观类型面积不同程度减少,其中耕地减少的面积最多,为4322 km2,建设用地和水域面积呈增加趋势。在景观水平上,2000~2018 年湖北省的景观破碎化程度升高,香农多样性指数(SHDI)和香农均匀度指数(SHEI)都呈上升趋势,这说明不同景观类型的多样性逐步增加,景观异质性增强。研究区景观格局变化受到自然因素和人文因素的共同影响,人口和经济因素是湖北省2000~2018 年景观格局变化的主要驱动因素。 相似文献