表碛覆盖型冰川的提取方法及变化     

薛娇  姚晓军  张聪  周苏刚  褚馨德 《冰川冻土》2022,44(5):1653-1664

表碛覆盖型冰川是山地冰川的一种特殊类型,表碛的存在使得其对气候变化呈现出不同的响应特征。基于2011—2020年Landsat TM/ETM+/OLI遥感影像和ASTER DEM数据,在综合分析表碛光谱、地形和地表温度特征基础上提出TDSI（temperature NDDI slope ice）方法,并将其用于提取中国境内托木尔冰川等6条大陆型冰川和雅弄冰川等3条海洋型冰川。结果表明：基于TDSI方法提取表碛覆盖型冰川的总体精度为91.23%,其中大陆型和海洋型表碛覆盖冰川的精度分别为91.20%和90.97%。2011—2020年6条大陆型冰川和3条海洋型冰川面积平均减少0.06%和0.11%,而表碛面积分别增加了11.92%和18.35%。大陆型冰川表碛主要分布在其中值海拔以下,而海洋型冰川表碛分布范围更广,近10年间二者均呈现向冰川上部扩张趋势。气温上升是冰川消融退缩和表碛增加的主要原因,同时冰川流速变化和终碛湖演变也对表碛变化有一定影响。  相似文献   

Azerbaijan's resource wealth: political legitimacy and public opinion   总被引：2，自引：0，他引：2  

SHANNON O'LEAR 《The Geographical journal》2007,173(3):207-223

After considering how well Azerbaijan's economy follows the trajectory of a 'resource curse' state, this paper investigates the political dimensions of the resource curse evident in Azerbaijan. Of particular interest is how Azerbaijan appears to establish external and internal political legitimacy. These dimensions of sovereignty are not necessarily balanced or present in equal measure. The paper assesses the recent transition in leadership in Azerbaijan as well as Azerbaijan's interactions with, and assessment by, the international community. Additionally, national survey data provide insights into public concerns, satisfaction with government policy, and views on democracy and freedom of expression. The paper concludes that at present there appears to be sufficient public expectation for future benefits, combined with institutional stability, to stave off widespread political instability for the time being.  相似文献   

中国附近海域地磁偏角图及其数学模式(1990.0)   总被引：2，自引：0，他引：2  

夏国辉  里弼东  张凤玉  李进杰 《测绘学报》1994,(1)

本文介绍了中国附近海域地磁偏角模式的建立和“中国邻近海区地磁偏角图”的编绘以及质量分析。在建立中国附近海区地磁偏角模式时，使用了3000多个地磁测点和地磁台站及国际参考地磁场资料，采用的方法是泰勒多项式。对海区地磁偏角模式和海区地磁图作了对比分析，其效果是好的。海区地磁偏角模式和“中国邻近海区地磁偏角图” 清楚地反映出我国南沙群岛地区尺度为1000余公里的磁异常，解决了中国地磁图和世界地磁图在这一海区未能解决的问题。海区地磁偏角模式的建立和海区地磁偏角图的绘制出版，大大地提高了我国海区及其邻近海域地磁偏角导航的精度。  相似文献   

What makes territory important: tangible and intangible dimensions     

Daniel J. Dzurek 《GeoJournal》2005,64(4):263-274

Conflicts over territory have resulted in innumerable wars and other violent incidents, but the reasons that some territory is more highly valued or volatile than other areas may not be obvious. This paper demonstrates a taxonomy for analyzing international territorial disputes that seeks to capture their tangible and symbolic dimensions and to weigh them as the international community might. Twenty-six territorial disputes, including offshore areas and separatist issues, were examined and scored according to 15 criteria for objective prominence and 7 criteria related to how a country might view the dispute in terms of its national interest. The taxonomy used Saaty’s Analytic Hierarchy Process to identify tangible and intangible properties, measure their interrelations, and produce intermediate and overall ranks. Each dispute was evaluated for prominence by examining intensifying (symbolic) factors, measures of magnitude, and characteristics that retard resolution. The magnitude of a dispute was judged to contribute the most to overall prominence, having twice the weight of the other two factors. The top five disputes in terms of prominence were the Kurdish issue, Kashmir, Tibet, Nagorno-Karabakh, and Xinjiang. The second hierarchy evaluated the disputes from the perspective of an international actor, in this case the United States. When judged by U.S. national interest, the most important factors were the deployment of U.S. forces in the claimant countries and if one of the claimants were a U.S. ally. Finally, the results from the two hierarchies were compared.  相似文献   

Distancing Asylum Seekers from the State: Australia's evolving political geography of immigration and border control     

Andonea Dickson 《The Australian geographer》2015,46(4):437-454

Australia's border enforcement strategies and immigration control policies operate in distant geographies, concealed from human rights groups, media and the public. From offshore detention to militarised maritime defence operations, Australia's exclusion of asylum seekers is increasingly dependent upon geographical processes that ensure asylum seekers do not have access to the state's systems of protection. This article explores a critically overlooked geopolitical strategy of mobility regulation that relies on processes simultaneously expanding geographies of control, while contracting spaces of rights. The outcome of these rapidly evolving bordering practices is the exaggeration of the distance separating asylum seekers from the state, suspending them within a space devoid of an operational system of rights, and emphasising a new and restructured maritime legal geography.  相似文献   

高精度缓冲区边界相向逼近求交算法研究及实验     

宁方辉  董箭  彭认灿  黄忠刚  王云 《海洋测绘》2013,(6):18-21

针对海洋划界等距离线/中间线方法中双方距离比例不为1∶1时的海洋划界存在的不足,探讨了基于欧氏平面的距离等比例线法及其后续研究存在的精度无法满足海洋划界的实际应用需求的问题,提出了基于地球椭球体解算距离等比例线的高精度缓冲区边界相向逼近求交算法,并阐述了该算法的基本原理和实现步骤,最后结合海洋划界实例,对该算法的有效性进行了验证。  相似文献   

GPS设备海上动态定位精度检测新方法     

宋超  郝金明 《测绘科学技术学报》2012,29(3):183-187,191

为解决GPS设备海上动态定位精度检测的问题,提出了利用高精度全站仪对GPS设备动态跟踪进行动态定位精度评定.阐述了检测基准数据的采集和处理,以及利用惯性测量设备提供的姿态数据将GPS定位数据归算到检测基准.简要介绍了进行动态定位精度评定所采用的方法,并对系统的误差进行了分析.最后通过实验验证了新方法的有效性.  相似文献   

基于海事大数据的港口感知计算     

陈龙彪  张大庆  李石坚  潘纲 《地球信息科学学报》2016,18(11):1485-1493

随着港口信息化建设的推进,积累了大量来源多样、结构各异的海事大数据,为了解港口城市的生产力和区域经济发展水平提供了新的契机。本文综合介绍了作者近期关于如何利用海事大数据进行港口感知计算的工作,给出了一个基于海事大数据的港口感知计算框架,利用船舶GPS轨迹、船舶属性、港口地理信息和港口设施参数等多源异构海事大数据,估算出一系列反映港口生产力的指标,从而对港口进行综合评价和比较。首先,利用船舶轨迹和港口地理信息数据,自动检测船舶在港口码头中的靠泊装卸事件;然后,利用船舶属性和港口设施数据,自动估计出每次靠泊装卸事件的货物吞吐量;最后,对各个港口码头的靠泊船数和货物吞吐量进行统计,从而计算出一系列港口生产力指标,包括到港船数、货物吞吐量、码头作业效率和泊位利用率等。在2011年的海事大数据上的实验结果表明,本框架能准确地估算出上述港口生产力指标。同时,以香港为例对上述港口的生产力指标进行分析,探讨基于海事大数据的港口感知计算框架在提高港口生产效率、优化海运航线中的积极作用。  相似文献   

中国海洋产业的结构与布局研究展望   总被引：3，自引：0，他引：3  

马仁锋  李加林  赵建吉  庄佩君 《地理研究》2013,32(5):902-914

海洋产业结构与布局是海洋经济地理学研究的核心领域与主体内容,国内相关文献日益丰富,但海洋产业结构与布局研究尚未形成完整体系。梳理现有文献发现:国内研究存在起步晚、发展缓慢,高层次研究成果少且增长慢,以区域实证研究为主、理论创新研究较少等问题,现有研究集中在6方面:①海洋产业结构与布局的内涵、规律及其与陆域布局差异探索;②沿海省份或大城市海洋产业结构的现状与问题、结构优化与主导产业选择、产业结构绩效评价、竞争力与趋势研究;③区域海洋产业布局模式及优化政策支撑体系研究;④海洋资源与环境的产业承载力评价及海洋功能区划研究;⑤海洋产业集群,尤其是港航集群的初步探索;⑥国外海洋产业发展态势、统计标准与区域海洋产业合作探索。本文初步总结了国内对海洋产业结构与布局研究文献的增长规律,并立足于海洋产业结构与布局研究趋势,指出未来应加强海洋产业结构与布局的前沿领域及理论体系探索,并为我国海洋经济示范区建设提供科学指导。  相似文献   

基于3维GIS的镇江市内河水上搜救应急指挥管理系统设计与实现     

赵永富 《测绘与空间地理信息》2012,(5):48-50,56

针对镇江市内河水上突发事件的特点,在3维GIS平台的基础上,整合CCTV视频监控系统、GPS定位系统、海事通等先进的手段,在突发事件发生时,该系统能及时预警,准确定位突发事件的位置,进行总体指挥调控,形成实施应急预案的交互式实战指南,为应急管理提供便捷的工具,为指挥决策提供辅助支持手段。  相似文献