海气相互作用对“格美”台风发展的影响研究   总被引：3，自引：3，他引：0  

刘磊  费建芳  林霄沛 《大气科学》2011,35(3):444-456

西北太平洋是全球唯一一年四季都有热带气旋生成的海域,同时,我国沿海紧临该海域,是受热带气旋影响最为严重的国家之一.本文通过建立海气耦合模式,以西北太平洋西边界流系源区为研究区域,通过对"格美"台风的数值模拟结果分析,研究海气相互作用对热带气旋发展的影响,对提高台风的数值模拟及预报水平有重要意义.研究表明:耦合作用引起的...  相似文献   

Study on the migrant labour force of China in recent years     

Xiaopei Yan 《中国地理科学(英文版)》1997,7(1):19-29

This paper, taking Nanhai City of Guangdong Province as an example, focuses on five interrelated aspects of the migrant labour force of China in recent years. Attention is initially paid to the background of the labour migration from inland towards coastal area. Then, the demographic characteristics of the migrant labour force are analysed before turning to the analysis on the reasons for the migration. Fourthly, the impacts of the migrant workers on the socio-economic development of Nanhai City and the problems are examined. Finally, the prospects and some suggestions for the labour migration are put forward. Migrant labour force is sometimes called floating population by both Chinese and western scholars.  相似文献   

Bearing capacity of strip footings on <Emphasis Type="Italic">c</Emphasis>–<Emphasis Type="Italic">φ</Emphasis> soils with square voids     

Haizuo Zhou  Gang Zheng  Xiaopei He  Xiaomin Xu  Tianqi Zhang  Xinyu Yang 《Acta Geotechnica》2018,13(3):747-755

The presence of underground voids has an adverse influence on the performance of shallow foundations. In this study, the bearing capacity and failure mechanism of footings placed on cohesive-frictional soils with voids are evaluated using discontinuity layout optimization. By introducing a reduction coefficient, a set of design charts that can be directly applied to the classical bearing capacity formulation is presented. The results indicate that the undrained bearing capacity with voids is sensitive to soil weight and cohesion, as both the bearing capacity and stability issues exist in the problem. The failure mechanism is directly related to a variety of soil properties, the locations of single voids, and the horizontal distance between two voids. The presence of voids has a more dominant effect on c–φ soils compared to that on undrained soil. An interpretation of the critical and adverse locations for single-void and dual-void cases with various soil strengths is presented.  相似文献   

Study of the comprehensive risk analysis of dam-break flooding based on the numerical simulation of flood routing. Part I: model development     

Ruirui Sun  Xiaoling Wang  Zhengyin Zhou  Xuefei Ao  Xiaopei Sun  Mingrui Song 《Natural Hazards》2014,73(3):1547-1568

Dam-break floods have been of increasing concern to safety engineers and decision makers. The presence of complex terrain in inundation areas multiplies the simulation difficulty of flood routing. In previous studies, representing the flood routing parameters empirically does not reflect the characteristics of flood routing, which strongly influences the accurate assessment of the dam-break consequences. The basis for carrying out dangerous reservoir reinforcement is just engineering safety, without considering the actual situation of downstream areas. In this study, a comprehensive risk analysis of the dam-break flood was implemented based on the numerical simulation of flood routing. First, coupled with the volume of fluid method, a three-dimensional k–? turbulence mathematical model was developed for flood routing in complex inundation areas. Then, based on the flow parameters obtained through computational fluid dynamics modeling, the attribute measure methodology was used for the evaluation of consequences combined with the calculation of the dam-break consequences (loss of life, economic loss, social and environmental influence). Furthermore, a methodology containing the combined weight method and the technique for order performance by similarity to ideal solution method was proposed for risk ranking of dangerous reservoirs due to its logical consideration of scalar values that simultaneously account for both the best and worst alternatives. Finally, a sensitivity analysis was performed to provide information about the stability of risk ranking. The aforementioned model and methodology are applied to a case involving five reservoirs in the Haihe River Basin in China for Part II of this study.  相似文献   

Study of the comprehensive risk analysis of dam-break flooding based on the numerical simulation of flood routing. Part II: Model application and results     

Zhengyin Zhou  Xiaoling Wang  Ruirui Sun  Xuefei Ao  Xiaopei Sun  Mingrui Song 《Natural Hazards》2014,72(2):675-700

The present model and methodology described in Part I of this work are applied to perform a comprehensive risk analysis of the dam-break flood of five reservoirs in the Haihe River Basin, China. The results indicate that the three-dimensional numerical simulation considering complex terrain can reflect the characteristics of flood routing and the three-dimensional phenomena. Based on the simulation results, it can be concluded that the risk grades of the consequences induced by a gradual or instantaneous dam break of the Dongwushi reservoir are extremely serious, as determined through the attribute synthetic approach. The results obtained from ranking the risk by the technique for order performance by similarity to ideal solution method are that the Dongwushi reservoir has the most serious consequences when the dam breaks followed by the Lincheng reservoir, the Miaogong reservoir and the Yunzhou reservoir, and the Youyi reservoir has the least severe consequences. Though the ranking of the relatively comprehensive risk coincides with that of the consequences, the dam safety measured by the dam failure probability plays an important role in ranking the risk. A sensitivity analysis is performed by individually increasing the weight of each criterion by 20 %, and the ranking order is not changed, suggesting that the evaluation model is reasonable, stable and reliable.  相似文献   

深圳市城中村“非正规住房”空间特征与演化研究     

赵静  闫小培  朱莹 《地理科学》2016,36(12):1802-1810

基于住房普查和建筑普查资料,对深圳市城中村“非正规住房”的空间特征与演化进行研究。得出以下结论：① 城中村“非正规住房”的空间集聚特征明显并形成若干集聚区,且表现出明显的圈层分化,非正规住房规模比重从城市中心到边缘呈先增长后降低的发展态势。② 影响城中村“非正规住房”空间结构的主因子包括规模因子、住房构成因子、增长因子、建筑特征因子和使用状态因子,城中村“非正规住房”可以划分为边缘增长型、空间集聚型、相对稳定型和中心转化型等4种类型。③ 深圳市城中村“非正规住房”的发展演化过程包括形成阶段、快速发展阶段、高潮阶段和缓慢增长阶段,不同阶段的非正规住房具有差异化的演化背景与空间结构特征。  相似文献   

基于文献引用关系和知识图谱的时空关系研究热点分析   总被引：1，自引：0，他引：1  

古杰  周素红  闫小培  柴彦威  郑重 《地理科学进展》2013,32(9):1332-1343

本文采用“Web of Science”数据库收录的1999-2013年期间发表的探讨时空关系相关文献,包括2263篇直接文献和这些文献引用的78139篇参考文献为基础数据,采用Histcite软件构建时空关系研究文献数据库,结合Citespace软件对该数据库进行文献引用关系和知识图谱的可视化处理,并对热点文献进行解读与分析,从而分析时空关系研究的研究热点和发展趋势。研究发现:2000年前后,时空关系研究与GIS结合逐步突破了传统时间地理学研究的技术瓶颈和研究框架,迅速进入了一个文献爆炸的阶段,研究的内容逐步从时空行为的描述转向对时空关系的解释。随着时空GIS技术的不断成熟,本领域的研究更多地把时空行为作为一种变量,对各种时空现象和社会问题进行解释,而不仅仅是一个被描述和解释的对象,其学科应用价值将逐步突显。  相似文献   

经济地理学视角下的物流活动研究进展及启示   总被引：2，自引：1，他引：1  

宗会明  周素红  闫小培 《地理科学进展》2010,29(8)

随着全球生产网络和现代物流研究的兴起,物流对于提升地区和企业的竞争力具有举足轻重的地位和作用.现阶段的物流研究主要集中于管理学和交通地理学2个学科.管理学侧重于研究物流组织和企业物流效率的提高,缺乏整体和空间的视角,而交通地理学则侧重于以货物流通为代表的传统物流研究,对于现代供应链及物流组织研究不够,二者各有研究优势和不足.经济地理学对物流活动的研究经历了传统物流活动研究、物流活动被遗忘、物流研究的被重新认识和发现3个阶段.在当今经济地理学"社会、制度、文化转向"背景下,经济地理学将在日益复杂的现代物流网络研究中发挥重要的作用,现代物流活动的相关研究,主要是由交通地理学者借鉴经济地理学理论对物流活动进行的研究.及经济地理学者对生产领域研究时对物流活动不经意的涉及,研究方向主要包括:全球生产网络下现代物流的性质和作用,现代物流组织结构研究,现代物流活动的空间表现及发展动力机制4个领域.总体而言尚处于研究起步阶段.最后,文章提出了对当代中国经济地理学对物流活动研究的几点启示.  相似文献   

国外非正规部门研究进展   总被引：2，自引：0，他引：2  

尹晓颖  闫小培  薛德升 《地理科学进展》2010,29(12)

国外非正规部门的研究始于20世纪70年代,最初研究的对象主要集中在发展中国家和地区,随着研究的深入,发现发达国家和地区也存在非正规部门,但存在方式和形成机制有别于发展中国家和地区.通过对国外非正规部门研究文献的系统梳理和分析,表明国外非正规部门的研究已形成一定的研究体系和理论成果,研究内容主要涉及非正规部门的边缘性和异质性等特征,非正规部门的空间集聚与分异,非正规部门存在与发展的理论,包括贫困就业论、二元经济论、规制论和嵌入论等,非正规部门与正规部门的联系,非正规部门的经济、社会影响以及非正规部门的正规化与政策等方面.但在从事非正规经济活动的人的空间特征、从综合视角分析非正规部门的形成发展过程、非正规部门对地域空间的影响以及对比研究和定量研究方面还较为欠缺.  相似文献   

广州信息服务业增长的地域类型分析   总被引：6，自引：0，他引：6  

阎小培 《热带地理》1999,19(1):18-22

采用第三产业普查数据,用聚类方法,详尽分析了广州信息服务业增长的地域类型,揭示了在信息技术产业化和产业结构高度化的背景下,城市信息服务业的地域运动规律,并为合理布局和发展信息服务业提供理论基础  相似文献