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1.
In recent years, melting and calving happen in the Antarctic ice shelves. In this paper, seven periods of coastlines were applied to provide an analysis of the ice front changes of Ross, Filchner-Ronne and Amery ice shelves with the inclusion of 1997 and 2000 Radarsat products, 2003/2004 and 2008/2009 MODIS products and 2006, 2012, 2015 coastline which were extracted from MODIS images. Change area, SCE (Shoreline Change Envelope) and NSM (Net Shoreline Movement) were applied to analyze the variation of the ice shelf front. The results shows that, the ice front of Amery ice shelf has advanced since 1997 and the total outward extension distance of the ice front was about 20 to 25 km while the advance area reached 3.03×103 km2. Ross ice shelf and Filchner-Ronne ice shelf continued to advance after ice calving events under the driver action of glacier. However, the advance area was less than the retreat area and the net change area is respectively -9.39×103 km2 and -5.86×103 km2. The retreat distance of the collapse area were up to 53 km and 39 km in the two biggest ice shelves. 相似文献
2.
Water-poverty relationships in the coastal town of Mbour (Senegal): Relevance of GIS for decision support 总被引：1，自引：0，他引：1
Néné Makoya Toure Alioune KaneJean François Noel Vincent TurmineValentin Nedeff Gabriel Lazar 《International Journal of Applied Earth Observation and Geoinformation》2012,14(1):33-39
Coastal area is always a zone with complex problems. Due to the attraction they exert, are facing many social problems. Therefore, a coastal city is usually a city with problems. Its extension, caused by the influx of people from different backgrounds, creates an increased demand for services. One of the problems frequently encountered, especially in Senegal, is access to water. The problem of access to water is poorly treated, without being correlated with the urban evolution, i.e. with increasing population and demand growth. The water resource is facing numerous complications such as the lack of integrated management, integration issues at the governance level, where the local factor is often forgotten.The town of Mbour, object of our study, does not come out of that lot, being an attractive coastal city, from an African country. This indicates the need for an integrated management oriented from local to a global basis and not vice versa. The study presented in this paper indicates that a large proportion of the population has not access to a verified drinking water system and uses water from wells or standpipes. Half of the surveyed population (50%) has no access to a water supply system. The water poverty map of the town overlaps with that of the general poverty excepting few neighborhoods. This means that even areas that are not affected by poverty have a very low or poor access to water, which so far remains the perverse effect of the reform of the Senegalese water sector in 1995. 相似文献
3.
Joon Heo Jung Hwan Kim Jin Woo Kim 《International journal of geographical information science》2013,27(9):1165-1177
Coastline recession is one of the best indicators of coastal erosion. Three methods for computing coastline recession – the baseline approach, the dynamic segmentation approach and the area‐based approach – have been used, each of which has one or more drawbacks. To overcome these problems, a new methodology for measuring coastline recession is proposed, using buffering and non‐linear least squares estimation. The proposed method was compared with the three existing methods with respect to two simulated cases and two real coastlines. Test results confirmed that the new method is more reliable than the three other methods, all of which are susceptible to variability of recession, scale, number of line segments, length of coastlines and direction of the baseline. The proposed method, incorporating two physically meaningful values – magnitude and variability of coastline recession according to the mean and standard deviation of coastline offsets, respectively – presents itself as an effective alternative method of assessing coastline recession. 相似文献
4.
江苏淤泥质海岸海岸线分形机理研究 总被引：4，自引：0，他引：4
结合国内外分形研究进展,系统探讨了江苏淤泥质海岸海岸线的分形机理问题,指出;江苏海岸的形成受到了构造和河流泥沙淤积的双重作用,而海岸线的走向则受到了构造,河流淤积,滩面物质组成与沿海黄海沿岸流的共同作用;另外,江苏海岸线分维的变化与海岸的淤积和侵蚀有着必然的联系;再者,江苏海岸物质组成具有分形性质,这是江苏海岸线具有分形性质的物质基础。 相似文献
5.
Two commonly used definitions of coastline are compared and analyzed in this article. To build a more perfect digital tide-coordinated coastline model in China, we should first solve the problems of the existing definition and unclear algorithms of China’s coastline. On the basis of defining the coastline in China as the intersection of coastal land and the mean high water spring (MHWS), it should be further revised, and defined either as an intersection of coastal land and the MHWS or as a mean higher high water level (MHHWL) considering the diversity of tidal characteristics in China Sea areas. Since MHWS is related to the extreme of the lunar phase and MHHWL is related to the extreme of the angle of the lunar declination elevation, the algorithms to obtain them are more complicated than that of mean high water (MHW) used in the United States. We should consider the specific law of tidal movement in different tide types of the predominantly semidiurnal or diurnal sea areas in China when studying the precise algorithms for MHWS and MHHWL. Several experiments show that the difference between the two types of calculations of coastal height, such as water level observations and tidal predictions, is within centimeter level. The research results of this article have a certain reference value for countries with similar coastline features as in China. 相似文献
6.
海岸线的动态变化监测可为海岸带防护、海岸带资源开发利用和可持续发展过程中的决策支持提供理论支撑。文中基于1973-2017年覆盖连云港市的Landsat系列和GF系列卫星影像数据,结合海岸线分类体系,提取了连云港市10期海岸线信息,并分析了海岸线演变特征及其成因。结果表明:(1) 2017年连云港市海岸线总长度为205.90 km,主要岸线类型为建设围堤和港口岸线,两类岸线总长为120.52 km,占总岸线长度的58.53%;(2) 1973-2017年连云港市海岸线长度整体呈现增长态势,44年间海岸线长度共增长了57.17 km,年增长率约为1.3 km/a。连云港市海岸线主要增长的岸线类型为建设围堤、港口岸线和生物岸线;(3) 44年间,连云港市海岸变化主要的海岸线类型为粉砂淤泥质岸线、生物岸线、港口岸线、建设围堤和盐田围堤;(4) 2017年连云港市自然岸线长度为69.15 km,占总岸线长度的33.6%,44年间,自然岸线长度减少了28.8km,年减少率为0.65 km/a。自然岸线减少的原因主要为养殖业发展、城市扩张建设和港口建设。 相似文献
7.
David A. Greenberg Frédéric Dupont Florent H. Lyard Daniel R. Lynch Francisco E. Werner 《Continental Shelf Research》2007
The baroclinic and barotropic properties of ocean processes vary on many scales. These scales are determined by various factors such as the variations in coastline and bottom topography, the forcing meteorology, the latitudinal dependence of the Coriolis force, and the Rossby radius of deformation among others. In this paper we attempt to qualify and quantify scales of these processes, with particular attention to the horizontal resolution necessary to accurately reproduce physical processes in numerical ocean models. We also discuss approaches taken in nesting or down-scaling from global/basin-scale models to regional-scale or shelf-scale models. Finally we offer comments on how vertical resolution affects the representation of stratification in these numerical models. 相似文献
8.
《海岸线保护与利用管理办法》是我国专门针对海岸线管理的首部规范性文件,弥补了我国海岸线管理的空缺。文章简要介绍《海岸线保护与利用管理办法》出台的背景;详细分析海岸线保护与利用管理的重要举措:(1)提出自然岸线保有率控制制度,(2)提出海岸线分类保护制度,(3)实施自然岸线保护与利用的年度计划管理,(4)编制全国和省级海岸线整治修复五年规划和年度计划以及建立全国海岸线整治修复项目库;阐述《海岸线保护与利用管理办法》对海岸线保护的作用与意义;最后对全面加强海岸线保护与利用管理提出建立健全各项配套制度、不断完善技术标准体系以及开展海岸线保护管理专项行动的建议。 相似文献
9.
Flooding is one of the most costly natural disasters and thus mapping, modeling and forecasting flood events at various temporal and spatial scales is important for any flood risk mitigation plan, disaster relief services and the global (re-)insurance markets. Both computer models and observations (ground-based, airborne and Earth-orbiting) of flood processes and variables are of great value but the amount and quality of information available varies greatly with location, spatial scales and time. It is very well known that remote sensing of flooding, especially in the microwave region of the electromagnetic spectrum, can complement ground-based observations and be integrated with flood models to augment the amount of information available to end-users, decision-makers and scientists. This paper aims to provide a concise review of both the science and applications of microwave remote sensing of flood inundation, focusing mainly on synthetic aperture radar (SAR), in a variety of natural and man-made environments. Strengths and limitations are discussed and the paper will conclude with a brief account on perspectives and emerging technologies. 相似文献
10.
The turbulence structure of a stable marine atmospheric boundary layer in the vicinity of a coastal headland is examined using aircraft observations and numerical simulations. Measurements are drawn from a flight by the NCAR C-130 around Cape Mendocino on the coast of northern California on June 7 1996 during the Coastal Waves 96 field program. Local similarity scaling of the velocity variances is found to apply successfully within the continuously turbulent layer; the empirical scaling function is similar to that found by several previous studies. Excellent agreement is found between the modelled and observed scaling results. No significant change in scaling behaviour is observed for the region within the expansion fan that forms downstream of the Cape, suggesting that the scaling can be applied to horizontally heterogeneous conditions; however, the precise form of the function relating scaled velocities and stability is observed to change close to the surface. This result, differences between the scaling functions found here and in other studies, and the departure of these functions from the constant value predicted by the original theory, leads us to question the nature of the similarity functions observed. We hypothesize that the form of the functions is controlled by non-local contributions to the velocity variance budgets, and that differences in the non-local terms between studies explain the differences in the observed scaling functions. 相似文献