20世纪40年代初以来中国大陆沿海主要海湾形态变化   总被引：11，自引：1，他引：10  

侯西勇  侯婉  毋亭 《地理学报》2016,71(1):118-129

受气候变化和人类活动的影响,中国海岸带正在经历各种剧烈的变化,海湾形态变化是其中的一个重要方面.基于地形图资料与遥感影像提取20世纪40年代初至2014年7个时相的中国大陆沿海主要海湾的空间信息,进而分析海湾岸线类型结构,开发利用程度和空间位置的变化特征,以及海湾面积,形状和重心分布的变化特征.结果表明,20世纪40年代初以来,中国大陆沿海主要海湾的形态变化显著且复杂,主要体现为:海湾岸线的结构变化显著,自然岸线的长度和比例急剧减少;海湾岸线的开发利用程度持续增强;海湾岸线普遍背陆向海运动;海湾面积普遍大幅萎缩;海湾形状总体趋向复杂但个体间的差异在缩小;海湾重心分布位置普遍背陆向海迁移;海湾变化具有显著的时空差异性等.总的来说,以围填海为主的人类活动是导致海湾发生上述变化特征的主要原因.通过研究,指出应该对中国的海湾进行功能定位划分和分类管理,通过强化以海湾为基本单元的管理,促进中国海岸带综合管理能力的提高和管理目标的实现.  相似文献   

Meeting the Challenge of Systemic Change in Geography Education: Lucy Sprague Mitchell’s Young Geographers     

Roger M. Downs 《The Journal of geography》2016,115(1):3-11

The history of K–12 geography education has been characterized by recurrent high hopes and dashed expectations. There have, however, been moments when the trajectory of geography education might have changed to offer students the opportunity to develop a thorough working knowledge of geography. Lucy Sprague Mitchell’s geography program developed in the 1920s and 1930s was brilliant in its conception and execution but it did not lead to large-scale systemic change. Analyzing the origins, development, and outcome of her program suggests the conditions that facilitate and inhibit systemic change, and therefore perhaps we can learn to capitalize on comparable moments in the future.  相似文献   

Does prolonged illness contribute to adaptive land use practices among subsistence agricultural households in rural Mozambique?     

《Applied geography (Sevenoaks, England)》2016

The environmental effects of disease are broadly recognized but still not fully understood. The impact of health on economic development has been well-documented, as have how changes in land cover can contribute to poor health. However, little is known about how changes in health may impact land use and land cover. Fallowing has long been regarded as an advanced, sustainable land use decision employed by subsistence agriculturalists. In the presence of a prolonged illness, however, subsistence agriculturalists may also potentially use fallowing as a coping mechanism. In this paper we seek to understand the extent to which fallowing is used as a coping strategy by households facing a prolonged illness. If illness threatens a household's labor supply, it could affect their ability to cultivate all of their land and may impact food security and general economic well-being. Additionally, it may also impact the actual landscape, as previously agricultural land may revert to a transitional state or land abandonment. This study employs mixed methods to determine if unhealthy agricultural households use fallowing as a coping strategy, identifies whether or not unhealthy fallowing households are more vulnerable agriculturally and economically than their healthier fallowing counterparts, and examines whether there is a land cover effect that can be detected using Landsat TM/ETM + satellite imagery.  相似文献   

Conservation-induced resettlement as a driver of land cover change in India: An object-based trend analysis     

《Applied geography (Sevenoaks, England)》2016

Located in the foothills of the Indian Himalaya, Rajaji National Park was established to protect and enhance the habitat of the Asian elephant (Elephas maximus) and tiger (Panthera tigris). In 2002 the Van Gujjars, indigenous forest pastoralists, were voluntarily resettled from the Chilla Range (an administrative unit of Rajaji National Park) to Gaindikhata, a nearby area where they were granted land for agriculture. In this study we used a variety of remote sensing approaches to identify changes in land cover associated with the resettlement. The methods comprise two main approaches. First, we used object-based image analysis (OBIA) to identify the pre-resettlement land cover classes of use areas (representing agricultural expansion and adjacent areas of grazing, and collection of fuelwood and fodder) and recovery areas (representing areas where settlements were removed, and the adjacent areas of resource use). Secondly, we used trend analysis to assess the gradual and abrupt changes in vegetation that took place in use and recovery areas. To conduct the trend analysis we used BFAST (Breaks For Additive Season and Trend), which separates seasonal variation from long-term trends, and identifies breaks that can be linked back to disturbances or land cover changes. We found that the OBIA classification yielded high average class accuracies, and we were able to make class distinctions that would have been difficult to make using a traditional pixel-based approach. Pre-resettlement, the recovery areas were classified as mixed forest and riparian vegetation. In contrast, the use areas were classified primarily as grass dominated, brush dominated, and plantation forest, and were located relatively far away from riparian areas. Following the resettlement, the trend analysis showed a sudden change in the seasonal variation of NDVI in areas converted to agriculture. Areas neighboring the new agricultural land experienced sudden decreases in NDVI, suggestive of disturbances, at a higher rate than the same land cover types elsewhere. At the same time, these neighboring areas experienced a gradual overall increase in NDVI which could be caused by an expansion of leafy invasive shrubs such as Lantana camara in areas heavily used for biomass collection. The recovery areas also experienced a gradual increase in NDVI as well as sudden breaks to this trend, but we lacked evidence to connect these changes to the resettlement. Our findings support the claim that the resettlement has shifted pressure from more ecologically valuable to less ecologically valuable land cover types, and suggest that to some degree resource use pressure has increased outside the park. The study employs a novel synthesis of OBIA and trend analysis that could be applied to land change studies more broadly.  相似文献   

Spatial Concentration in Australian Regional Development,Exogenous Shocks and Regional Demographic Outcomes: a South Australian case study     

Peter Smailes  Trevor Griffin  Neil Argent 《The Australian geographer》2016,47(4):527-545

ABSTRACT

As a tribute to the massive contribution of our friend and colleague Graeme Hugo to the population and settlement geography of Australian rural areas, this paper presents a longitudinal study from his home State. It forms part of a wider study of the long-term demographic relationships between Australia’s rapidly growing regional cities and their surrounding functional regions. Of particular interest is the question of what effect the accelerating concentration of population and economic activity into a given regional city will have for the longer term demographic sustainability of its functional region as a whole. Taking the case of Port Lincoln, regional capital of most of South Australia’s Eyre Peninsula, it examines the nature of change in the functional region over the period 1947–2011, and investigates the forces feeding, and partly counteracting, the population concentration process, informed by concepts of evolutionary economic geography. In particular it traces the demographic impact (particularly differential migration and ageing trends) of exogenous shocks to the region’s essentially primary productive economic base during the period of major change from 1981 to 2011.  相似文献   

Vulnerability of Kuwait coast to sea level rise     

Mohammad M. M. Alsahli  Ahmed M. AlHasem 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2016,116(1):56-70

Assessing coastal vulnerability to sea level rise (SLR) at local and regional scales is a fundamental step for designing successful long-term coastal management plans. This study was thus designed to assess Kuwait coastal vulnerability to SLR at four scenarios (.5, 1, 1.5 and 2 m). Potential inundated areas and the number of people at risk were estimated based on these SLR scenarios. A coastal vulnerability index (CVI) map of Kuwait was then computed based on the lowest scenario using eight parameters: elevation, coastal slope, geomorphology, distance to 20-m isobath, population, land use, cultural heritage and transportation. The geographic distribution of inundated areas at an SLR of .5 m revealed that the northern islands of Kuwait and coastal areas along Kuwait Bay would be highly impacted, whereas the coastal area near Shuaibah Port was the most influenced among the southern coasts. Most of the coastal area exhibited a moderate vulnerability to SLR, especially the northern islands. This study presented an initial vulnerability assessment for Kuwait coasts to SLR, which can be extended with more variables. The integrated remote sensing and geographic information system methodology demonstrated in this study can be applied in similar studies elsewhere.  相似文献   

Map-Based Web Tools Supporting Climate Change Adaptation     

Tina-Simone Neset  Tomasz Opach  Peter Lion  Anna Lilja  Jimmy Johansson 《The Professional geographer》2016,68(1):103-114

This article discusses the state of the art in geovisualization supporting climate change adaptation. We reviewed twenty selected map-based Web tools, classified by their content and functionality, and assessed them by visual representations, interactive functions, information type, target audience, and how vulnerability and adaptation to climate change are addressed. Our study concludes that the tools (1) can be classified as data viewers with basic functionality and data explorers offering more sophisticated interactive functions; (2) mostly feature moderate or high richness of data content; and (3) predominantly target expert users.  相似文献   

风电场对草地植被生长影响分析——以内蒙古灰腾梁风电场为例   总被引：3，自引：0，他引：3  

李国庆  张春华  张丽  张蒙 《地理科学》2016,36(6):959-964

利用2000~2014年的MOD13Q1-NDVI数据,对内蒙古灰腾梁风电场及该电厂50 km缓冲区内的植被生长情况进行了分析。结合气象数据,重点探讨了风向对植被生长的影响。与2000~2008年风电场建设完成前植被生长相比,2008年后风电场运行对植被的生长产生了明显的影响,但影响范围和强度是不均匀的,结果表明：① 风电场运行对风电场区域内/外植被的影响机制是不同的,风电场区域内不利于植被的生长,而上/下风区域却有利于植被的生长;② 相对于风电场建成前,风电场建成后的2008 ~2014年缓冲区和风电场区域植被恢复比例分别上升了26.66%和13.14%,但上风区域却上升了51.83%,下风区域上升了41.07%。可见风电场上/下风区植被恢复比例,尤其是上风区植被的恢复比例要远高于其它区域;③ 距离风电场中心30~40 km的上风区很可能是受风电场影响最为明显的区域。  相似文献   

"地下水科学与工程"学科形成的历史沿革及其发展前景   总被引：1，自引：0，他引：1  

林学钰 《吉林大学学报(地球科学版)》2007,37(2):209-215

人类由逐水而居到凿井取用地下水是人类文明史的一大转折。和地表水相比,地下水具有分布广泛、水质良好、变化稳定、便于利用、不容易受污染等优点,因此它是理想的供水水源。地下水本身既是人类生存不可或缺的重要资源,同时也是一种地质营力、信息载体、生态环境因子和灾害因子。因此开展地下水的形成、赋存、运动规律的研究,以及合理开发、利用的工程技术、布局设计和实施等水文地质研究是一门关系到人类生活、社会需求和发展的重要学科。笔者着重论述了“地下水科学与工程”学科形成的历史是和人类社会的诞生、繁衍和发展紧密相关的。随着科学进步和国民经济的发展,该学科已从原来的基础学科逐渐向应用基础学科和应用学科相结合的方向发展。因此,今后在加强水文地质基础研究的同时,还应该十分重视满足国民经济需求和面向市场应用的研究。最后,从世界面临严重缺水和水污染的现实、科学发展的必然和国际学术组织和学者对地下水学科的重视,以及当前人才市场对该学科人才需求等方面指出,21世纪“地下水科学与工程”学科的发展具有很大的空间和十分广阔的前景。  相似文献   

石屏县土地更新调查的影像解译结果分析     

彭文甫  何政伟  周介铭  许辉熙  尹江涛  杨斌  杨洋 《测绘科学》2007,32(6):189-192,181

利用2005年SPOT-5高分辨率卫星影像,运用RS、GIS、GPS等新的技术手段,分析、提取了石屏县土地利用变化信息。结果显示,石屏县新的土地控制面积为3 041.37km2,与2004年变更调查统相比较,现有辖区面积增加0.53km2。土地利用类型以农业用地为主,面积达25.40 536×104hm2,占总土地面积的83.53%。通过以高分辨率卫星影像进行更新调查,有效掌握石屏县土地利用状况和动态变化,查清土地利用结构,调整土地供应,有效利用土地资源提供了翔实的基础资料和科学依据。  相似文献