Local food activity in the Republic of Ireland and Great Britain

Recent changes in local food supply systems have attracted substantial research interest, but little consideration has been paid to exactly where they occur. This article combines data from three studies to compare local food system development in England, Wales, Scotland and Ireland using a single index of food relocalisation, thereby exploring the usefulness of the Index across different social and political contexts. Four diagnostic indicators suggest that local food systems in the south west of Ireland and Britain are particularly well developed. The Index itself is a useful tool for making international comparisons, being easy to replicate and allowing the integration of different data sets. Perhaps its greatest utility is that it opens up new avenues for further research.     

1987—2017年海南岛海岸线变化特征遥感分析

利用海岸线、红树林和近海围塘养殖等多个遥感专题信息产品,从岸线年均变化速率、利用率和综合利用程度等方面综合分析了海南岛1987—2017年的海岸线变化特征,并通过典型岸线类型变化探讨了人类活动对海南岛海岸带资源的影响。分析发现：1）海岸线长度总体呈稳定增长趋势。由1987年的1 655 km增至2017年的1 890 km,其中自然岸线持续减少,人工岸线急剧增长。2）岸线类型多样性降低,倾向性明显;而岸线的利用程度不断提高,利用程度综合指数由1987年的237.34增加到2017年的285.03,人类活动对海岸线变迁的干扰作用越来越明显。3）陆海格局变化特征复杂,整体呈向海扩张的态势。多种人为因素共同作用是导致岸线不断变迁的主要原因,人工养殖塘的开发使红树林湿地遭到侵占,生物岸线减少,港口建设、近海人工岛建设等引起砂质岸线等自然岸线减少。     

Digital photogrammetry and kinematic GPS applied to the monitoring of Vulcano Island, Aeolian Arc, Italy

Digital photogrammetry and kinematic global positioning system (GPS) techniques are investigated and compared over a volcanic area as operational approaches to map the topography and monitor surface displacements. The use of terrestrial and airborne GPS to support the photogrammetric survey allowed for operational and processing time reduction without loss of accuracy. A digital elevation model (DEM) is obtained from the processing of the high-resolution digital imagery survey, which provides detailed information over a large area. The internal accuracy of the derived DEM has been verified by the comparison of two sets of data obtained from imagery acquired in different epochs; the observed root-mean-square error of residuals ranges from a few centimetres to 15 cm depending on the morphological features. Kinematic and pseudo-kinematic GPS surveys are performed to derive accurate 3-D coordinates at monumented benchmarks and accurate elevation profiles along footpaths. The average repeatability of the GPS measurements on benchmarks is 1 cm for measurement durations of 2–3 min. The standard deviation of interpolated vertical coordinates obtained at the crossings of kinematic GPS profiles is 4.3 cm. The high quality of these GPS coordinates justifies their use also for the validation of the photogrammetric DEM. A comparison of 6000 common points provides a standard deviation of residuals of 18 cm. The results show that the deformation pattern of a volcanic area can be rapidly and accurately monitored even in the absence of geodetic benchmarks. The integration of aerial photogrammetry with GPS kinematic surveys may be considered as an optimal approach for deriving high-resolution mapping products to be used in support of studies of volcanic dynamics.     

抗滑桩与桩顶弧形连系梁协同作用机理及计算分析

桩顶弧形连系梁通过约束桩顶位移,能够优化桩身的受力状态,且能提高抗滑桩的整体稳定性。与直线型连系梁相比,弧形连系梁的受力性能与拱形结构相似,以受压为主,能够充分发挥混凝土较高的抗压能力,通过抗滑桩及连系梁可将部分滑坡推力传递至滑体两侧稳定岩土体,降低了对滑床岩土体强度及抗滑桩桩身强度的要求。根据抗滑桩与连系梁之间的协同作用及变形协调,利用力法原理,建立柔度方程,求解桩顶与连系梁之间的约束冗力,进而计算连系梁及抗滑桩的内力和位移。通过算例表明,弧形连系梁较直线型连系梁内力分布均匀,与单桩及桩顶受直线型连系梁约束的排桩相比,弧形连系梁对抗滑桩的约束效果明显,而且约束效果随弧形连系梁矢跨比的增加而增强。     

南京市八卦洲旅游发展条件分析

通过对各种内部和外部因素的系统分析,文章认为八卦洲具有发展旅游的多方面内在优势,也存在一些不利因素,但更存在良好的发展机遇、建议：八卦洲的旅游开发应以建设生态旅游度假区为总体目标,进一步凸现“绿”、“水”、“野’’三大特点,努力营造人与自然和谐相处的生态旅游岛形象,重点开发休闲度假、观光旅览、康体娱乐、美食保健、野营修学、文化旅游等六大系列旅游产品。     

New Zealanders on the Population Geography of the Western Island

New Zealand origin academics have played a key role in the academic study of Australia's population in the post-war period. The paper argues that New Zealanders have contributed not only to the furthering of knowledge of the processes of change in the Australian population but have been important in the teaching of population geography in Australian universities, made inputs into policy relating to population and been influential in the development of the Australian Population Association. Major contributions have been made by New Zealanders not only in the traditionally strong areas of population geography such as internal and international migration but also in the areas of fertility, mortality and ageing.     

Prospects for the New Zealand Geographer Seeking a Lectureship in Britain

During 1993 advertised geography lectureships in British Universities reached unusually high levels, most probably due to major structural changes in tertiary education and the provision of funding attached to research ranking, superimposed on the general trends of increasing student numbers and an ageing academic population. As the research assessment exercise takes place every four years, and the new academic league tables have just been published, it is predicted that a similar surge in advertised lectureships will occur during 1997 and 1978. Research active New Zealand geographers are well placed to capitalise on this projected recruitment phase, which is likely to peak between April and July and again in November. Some specialist subjects within the discipline are in greater demand than others although their popularity may change over time. Many of the traditional obstacles that have in the past discouraged New Zealanders from targetting an academic position in Britain are now more perceived than real.     

Representing rurality? New Labour and the electoral geography of rural Britain

The first Blair administration faced clamorous criticism from some lobby groups for its handling of rural issues. Yet Labour has presented itself as a 'one–nation' party representing both urban and rural areas. This paper examines the basis of recent claims about the parliamentary representation of rural Britain, and analyzes the results of the last two General Elections. It illustrates how the malleability of the category of 'rural' allows for contrasting claims about rural representation, and highlights the continuity of party representation among those constituencies located outside the main urban areas in the 1997 and 2001 parliaments, despite regular rural protest.     

1960―2011年海陵岛气候与极端天气变化趋势分析

根据海陵岛闸坡海洋水文气象观测及《台风年鉴》资料,对海陵岛1960―2011年的气候与旱涝、暴雨、台风、极端温度、海面温度(SST)热事件等极端天气变化趋势进行分析。结果显示:海陵岛为边缘热带气候,近52年的升温率为0.21℃/10a;1963年为特旱年,1973、2001、2008年为特涝年;累年平均暴雨日数为9.5d/a,大暴雨日数为2.4d/a;严重影响海陵岛的热带气旋(中心进入海岸线1个纬距以内)累年平均1.43个/a;寒潮未曾出现,但有过严重寒害。在气候变暖背景下,20世纪80年代以来≥35℃极端高温日数总体上呈显著增加趋势,而≤5℃极端低温日数呈减少趋势。SST≥30℃、持续10d以上的热事件共出现23次。     

厦门岛城市空间扩张特征及其影响因素分析

海岸带是目前世界上城市化最集中的区域,海岛作为海岸带的一个特殊地理组成,其城市空间扩张过程可以理解为城市发展与自然地理环境之间相互耦合作用的结晶。本文以中国东南沿海的厦门岛为例,结合厦门岛城市发展的相关政策、城市规划、人口、产业等历史与现状资料的文本分析,通过图片修整和遥感地理信息分析相结合的方法,首先回顾厦门岛近100 年的城市化历程,分析厦门岛海岸线、岛屿形状、建成区、交通、行政区划及主要土地利用类型历史变化及城市空间扩张特征;然后从行政区划、城市总体规划、产业发展、地形、围填海、交通和人口等方面分别探讨影响海岛城市空间扩张的潜在决定因素;总结各种因素对海岛城市空间扩张的作用;以期为中国甚至世界其它沿海城市合理开发海岛,促进海岸带可持续城市化提供科学借鉴。     

鄂尔多斯地区城市热岛效应初步分析

在针对鄂尔多斯地区的城市热岛效应的研究时发现,找到没有受到人为干扰的站点十分困难,于是本文使用了相对的概念,即是受到人为干扰较少的站点作为对比站点。通过对近50年的气温数据资料,本文发现鄂尔多斯地区年相对城市热岛强度在1.2℃左右,春季的相对城市热岛强度最弱,冬季的最强。本文将发展较为缓慢的1961年—1990年30年划分为一个年代,发展相对快速的1991年—2010年20年划分为一个年代,发现鄂尔多斯地区热岛效应有所增强,但夏季有所减弱,春秋两季加强明显。     

涠洲岛海洋站1960-2010年DHW变化趋势分析

根据涠洲岛海洋站实测海表温度(SST)历史资料和该岛珊瑚礁普查(Reef Cheek)历史资料,采用相关分析和对比分析法探讨该站SST变化中夏季DHW(Degree Heating Weeks)的变化趋势及珊瑚白化的海洋站DHW临界值,结果表明:(1)1960-2010年涠洲岛DHW有轻微的上升趋势,与气候全球变暖统计...