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1.
1900-2009 年中国均一化逐月降水数据集研制   总被引:2,自引:0,他引:2  
李庆祥  彭嘉栋  沈艳 《地理学报》2012,67(3):301-311
收集、整理全国1900-2009 年110 年逐月站点历史降水量资料,采取标准正态检验(SNHT) 方法,对台站序列进行了均一性检验,并对部分明显不连续的站点序列进行了均一化调整和订正。在此基础上,分别对近百年降水距平序列和1971-2000 年气候标准值进行了网格化,形成了逐月网格化气候数据集(5°×5°,2°×2°),并采用经验正交展开(EOF) 技术方案进行了统计插补实验,形成了完整的5°×5°经纬度网格点数据集。基于不同分辨率网格数据集,建立了110 年中国降水变化序列,计算了110 年中年及季节降水量变化趋势。结果表明,中国近110 年来年降水量变化略呈下降趋势,但没有达到统计显著性水平,各个季节的情况略有差别。统计插补后对1900年以后几年的降水量略有下降,使得近百年线性趋势略上升。  相似文献   

2.
张杰  盛科荣  王传阳 《热带地理》2022,42(6):928-938
基于中国金融业企业网络数据和链锁网络模型建立城市网络,在解析金融网络空间格局的基础上,定量识别与测度了金融网络的影响因素,并探讨了关键因素的作用机理。研究发现:中国城市间金融网络的中心性体系呈现空间指向和路径依赖的特征,链接关系呈现纵深关联和层级分化的特征,核心―边缘结构呈现逐渐深化和有序分布的特征;关键资源、空间距离、区位条件和历史基础是影响金融网络空间格局的关键因素;择优链接、地理邻近和空间集聚是金融网络生长发育的动力机制。在网络发展环境下,中国城市化政策需要做出相应调整,支持城市在金融网络中选择差异化的发展路径,充分发挥金融网络对城市经济增长的供给引导功能,同时在更大空间尺度上推动城市之间的网络协作。  相似文献   

3.
The lower Nanaimo Group was deposited in the (forearc) Georgia Basin, Canada and records the basin's initiation and early depositional evolution. Nanaimo Group strata are subdivided into 11 lithostratigraphic units, which are identified based on lithology, paleontology, texture and position relative to both the basal nonconformity and to each other. Significant topography on the basal nonconformity, however, has resulted in assignment of lithostratigraphic units that are not time correlative, and hence, cannot reliably be used to accurately reconstruct basin evolution. Herein, we present a sequence stratigraphic framework for lower Nanaimo Group strata in the Comox Sub-Basin (northern Georgia Basin) that integrates both facies analysis and maximum depositional ages (MDAs) derived from detrital zircon. This stratigraphic framework is used to define significant sub-basin-wide surfaces that bound depositional units and record the evolution of the basin during its early stages of development. Seven distinct depositional phases are identified in the lower 700 m of the lower Nanaimo Group. Depositional phases are separated by marine flooding surfaces, regressive surfaces, or disconformities. The overall stratigraphy reflects net transgression manifested as an upwards transition from braided fluvial conglomerates to marine mudstones. Transgression was interrupted by periods of shoreline progradation, and both facies analysis and MDAs reveal a disconformity in the lowermost part of the Nanaimo Group in the Comox Sub-Basin. Stratigraphic reconstruction of the Comox Sub-Basin reveals two dominant depocenters (along depositional strike) for coarse clastics (sandstones and conglomerates) during early development of the Georgia Basin. The development and position of these depocenters is attributed to subduction/tectonism driving both subsidence in the north-northwest and uplift in the central Comox Sub-Basin. Our work confirms that in its earliest stages of development, the Georgia Basin evolved from an underfilled, ridged forearc basin that experienced slow and stepwise drowning to a shoal-water ridged forearc basin that experienced rapid subsidence. We also propose that the Georgia Basin is a reasonable analogue for ridged forearc basins globally, as many ridged forearcs record similar depositional histories during their early evolution.  相似文献   

4.
《Urban geography》2013,34(2):174-192
Subsistence gardens were a significant land use in the Columbus, Ohio metropolitan area from 1900 to 1940. Their existence, however, was materially erased from the city and discursively erased from its history after that period. This paper investigates the processes of that erasure, particularly in the American Addition neighborhood of Columbus, concentrating on the articulation of an urban normative that made such land uses appear contrary to "modern" urban development. At the same time, the existence of such practices and landscapes in the city was explained away by a crisis narrative of the garden that helped to support the idea that such practices did not produce "normal" urban spaces. The simultaneous material and discursive colonization of subsistence gardens as "relief" measures during the Great Depression left these landscapes and areas dependent on the City of Columbus, under whose control they were transformed into more "appropriate" cityscapes.  相似文献   

5.
张杰  盛科荣  王传阳 《干旱区地理》2022,45(5):1659-1670
核心-边缘结构的研究将加深对城市网络演化规律的理解。基于证券服务联系视角,解析了2005—2019年中国城市网络的核心-边缘结构演化特征及其影响因素。结果表明:(1) 中国城市网络核心区块的规模稳步扩张,同时城市核心度的分布趋于分散,推动着城市网络向多中心格局发展;城市网络的核心区块主要由城市群的核心城市组成,城市网络连通度的分布收敛于Zipf法则,预示着中国城市网络将呈现持续的等级结构特征。(2) 政治权力、市场潜力、知识资本、航空联系和经济开放决定了证券企业获取有价值信息流的能力,进而构成了中国城市网络核心-边缘结构生长发育的基础;城市的网络地位在很大程度上源于“场所空间”中的影响力,这意味着城市网络的发展可能会加剧中国城市经济的发展差距。  相似文献   

6.
新疆阿拉山口区域现代物流产业发展分析   总被引:8,自引:6,他引:2  
研究新疆西部阿拉山口区域物流活动,分析该区域发展物流产业的优势所在,着重分析论述该区域在地缘区位、物流腹地和市场、国际人通道以及与中亚五国产业互补等方面发展现代物流的优势所在,并找出组织发展阿拉山口现代物流的制约因素,最后针对制约该区域发展现代物流的因素,提出促进该区域发展现代物流的一些措施。从而起到促进该区域物流产业作为主导产业的发展,促成今后阿拉山口区域物流产业的规模化、一体化、集约化的发展。同时,这对优化新疆沿边产业结构、区域物流经济发展有借鉴作用。  相似文献   

7.
Dispute settlement mechanisms (DSMs), and the institutional architecture of free trade agreements, have been neglected in economic geography's contemplations of international trade or globalization. This article highlights the role of DSMs in free trade agreements, especially in relation to the World Trade Organization (WTO), and draws out some implications for local development. The study reviews literatures that have addressed the mandate and rationale of the WTO's formal and legalistic DSM, paying especial attention to the realist perspective on international trade, the issue of fairness, and implications of asymmetric power relations for local development. Economic geographers need to incorporate free trade institutional architectures in contemplations of local development.  相似文献   

8.
蒋小荣  杨永春  刘清  汪胜兰 《地理科学》2021,41(8):1419-1427
基于复杂网络分析与贸易增加值核算方法,借助ArcGIS、Ucinet和MATLAB等工具,对全球64个主要经济体货物、服务和增加值多重贸易网络的空间演化及其影响因素进行综合对比分析,结果表明:① 全球货物、服务和增加值贸易网络的紧密性和通达效率均呈现稳步提升趋势,服务贸易的网络化趋势更为显著;金融危机对网络的“互惠性”“异配性”产生较大影响;② 空间格局上均具有显著的“核心?边缘”等级性,区域层面上形成了亚太和欧盟地区两大“派系”,美、中、日、德为两大“派系”联系的枢纽节点;③ Top1网络表现出不同的演化特征,其中货物、服务和增加值贸易网络分别呈现“星型”“雪花型”和“星型+链式”空间组织结构。3类网络演化过程中中国的崛起态势令人瞩目;④ QAP(二次指派程序)分析显示,传统的GDP、地理距离、共同语言等因素对于3类网络的形成具有相似的较强解释力,要素禀赋差异和贸易制度是影响它们之间差异性的主要因素,但其显著性水平不高且趋于弱化。  相似文献   

9.
代内公平、国际贸易与可持续发展   总被引:5,自引:0,他引:5  
现阶段,不同国家或区域之间商品交流的种类与数量日益增大。由于发达国家与发展中国家在国际贸易中所扮演的角色不同,因此,在等经济价值交换规律的作用下,发展中国家的环境状况逐渐恶化。文章通过构建开放经济的物质流模型,探讨了物质交换行为对系统内部的自然环境的影响,并对1987年日本的物质流动状况进行了案例研究。分析表明,发达国家的经济发展水平在很大程度上依赖于其它国家内部自然资源与环境的支撑作用。  相似文献   

10.
1 IntroductionModelsofmetropolitanspatialevolutionlargelyderivefromexperiencesunderamarketeconomy .Developingworld patternsinmore government_directedsystemsremainunder_examined.This papercomparestheurbanspatialpatternsandenvironmentaleffectsofexplosivem…  相似文献   

11.
盛科荣  孙威 《地理科学进展》2012,31(12):1636-1644
区域双核结构模式是一种重要的经济地理现象。基于新经济地理学的研究视角和分析框架,论文构建模型,分析了规模经济和对外贸易推动区域双核结构模式的生成过程和经济机理。模型研究表明,规模经济和对外贸易是塑造区域双核结构模式的基本力量:规模经济的增强放大了本地市场效应,导致了区域核心城市的出现;对外贸易影响着沿海地区的经济地理优势,决定着港口区位核心城市和内陆地区核心城市的并存。山东半岛济南—青岛双核结构模式生成过程的实证研究也表明,双核结构模式是制造业活动完成由以手工业为主导向现代化大生产为主导转变、区域发展环境完成由相对封闭向相对开放转变之后才产生的经济地理现象。  相似文献   

12.
"This paper examines population change in the upper Braldu Valley of the Karakoram range in northern Pakistan between 1900 and 1990. Population has declined over the 90-year period of observation and the majority of that decline is accounted for by females.... The paper discusses apparent demographic trends in a contemporary and historical context and questions the extension of vague, unqualified, context-independent population statistics to an area where apparently they do not apply. It argues that only by interpreting demographic change from within such a local context can the relevance of population control policies be scrutinized. This paper is not an exhaustive demographic analysis but presents data from a little-studied region of the Himalayan area and is meant to open avenues for future research there." (EXCERPT)  相似文献   

13.
苏州市城市物流空间格局及物流企业发展路径   总被引:2,自引:0,他引:2  
随着城市经济的发展,城市物流已由单一考虑运输、仓储等环节向系统化、均衡化、综合化方向发展,已经成为21世纪城市可持续发展关键因素。本文以苏州市为研究案例,从区位优势、经济基础、经济结构以及物流资源等方面分析苏州城市物流的发展现状;引入“轴-辐”(hub—and—spoke)理论,构建苏州“一轴五辐”物流空间优化体系;探讨苏州市物流发展的路径选择;提出苏州市专业化物流企业发展模式,以推进苏州市物流产业的发展。提升苏州市在长三角城市群中的地位与作用。  相似文献   

14.
基于网络分析的城市影响区和城市群空间范围识别   总被引:1,自引:3,他引:1  
以不打破行政界线为前提,利用Huff模型,基于矢量数据,采用最短交通路网距离和城市综合规模值来综合测算腹地与中心城市之间的势能,根据势能确定腹地县域的归属,对全国地级及以上城市的空间影响范围进行识别,并和基于改进场强模型的城市影响腹地范围界定结果进行对比。以全国发育较成熟的15个城市群为对象,综合测定城市群的影响范围,并与城市群规划中的空间范围进行对比,提出城市群空间范围调整建议。并以长株潭城市群为例,通过社会网络分析方法,综合分析测定城市群的空间影响范围。研究结果可为城市(群)规划提供科学依据和方法参考。  相似文献   

15.
16.
王武林  龚姣  林珍 《热带地理》2021,41(6):1199-1208
“冰上丝绸之路”倡议为沿线国家贸易发展提供了机遇,可加速经济要素跨国流动,促进全球贸易的可持续发展。基于2019年37个“冰上丝绸之路”沿线国家贸易数据,运用复杂网络分析方法,研究37个“冰上丝绸之路”沿线国家贸易网络的拓扑结构特征、贸易社团及节点中心性的地理空间分布特征。结果表明:1)贸易网络具有良好的互通性和扩散性,且具有小世界特征和无标度性质,两极分化较为显著;2)贸易网络呈现出明显的“核心—边缘”圈层结构特征,德国、中国、美国、荷兰处于核心圈层,是贸易网络的枢纽;3)贸易网络可划分为1个北美社团、1个以东亚国家为主的社团和3个以欧洲国家为主的社团,其空间分布表现出连续性特征,各社团内部贸易联系密切,中国是所属社团的核心;4)贸易网络呈现出枢纽辐射式和全连通式共存的结构,强度中心性呈嵌入式的单元格局,接近中心性呈集中连片区块状分布特征,中介中心性的极化现象较为明显。  相似文献   

17.
全球生产网络的组织模式和空间特征具有复杂性。国际贸易壁垒作为经济全球化进程中的重要因素,对全球生产网络产生了极为重要的影响。本文以中加自行车贸易为例,结合对我国5 个地区23 家企业的调研资料,探讨了国际贸易壁垒如何影响了全球生产网络的组织模式和空间特征。研究结果显示,近年来关税、反倾销等壁垒对国际贸易影响显著。在国际贸易壁垒的作用下,第三方机构成为全球生产网络的核心组成部分之一,其介入为国际贸易提供了良好的平台和保障。全球生产网络各要素间的流动性也随着第三方机构的介入而不断增强,制造商的关注点逐渐由低成本控制向产品质量管理和劳动力管理等新方向转变。全球生产网络的空间组织形态呈现了新的特点。  相似文献   

18.
Geographically explicit historical land use and land cover datasets are increasingly required in studies of climatic and ecological effects of human activities. In this study, using historical population data as a proxy, the provincial cropland areas of Qinghai province and the Tibet Autonomous Region (TAR) for 1900, 1930, and 1950 were estimated. The cropland areas of Qinghai and the TAR for 1980 and 2000 were obtained from published statistical data with revisions. Using a land suitability for cultivation model, the provincial cropland areas for the 20th century were converted into crop cover datasets with a resolution of 1 × 1 km. Finally, changes of sediment retention due to crop cover change were assessed using the sediment delivery ratio module of the Integrated Valuation of Ecosystem Services and Trade-offs (In- VEST) model (version 3.3.1). There were two main results. (1) For 1950–1980 the fractional cropland area increased from 0.32% to 0.48% and land use clearly intensified in the Tibetan Plateau (TP), especially in the Yellow River–Huangshui River Valley (YHRV) and the midstream of the Yarlung Zangbo River and its two tributaries valley (YRTT). For other periods of the 20th century, stability was the main trend. (2) For 1950–1980, sediment export increased rapidly in the Minhe autonomous county of the YHRV, and in the Nianchu River and Lhasa River basins of the YRTT, which means that sediment retention clearly decreased in these regions over this period. The results of this assessment provide scientific support for conservation planning, development planning, or restoration activities.  相似文献   

19.
《Urban geography》2013,34(1):59-89
This investigation of demographic changes between 1990 and 2000 within African American employment concentrations in Chicago finds that the effects of immigration on African American employment differ by gender. Black women increasingly shared their niche industries with immigrant women without being displaced, a pattern of coexistence that indicates the primacy of gender in sorting women into employment. By contrast, similar patterns were absent between African American and immigrant men, and several niche industries reflected competition. Yet economic restructuring more significantly affected African American male and female employment than immigration. Among women, these same trends also affected immigrants. Both groups were adversely affected by the growth of low-wage employment in female-dominated, care-work jobs—their primary industries of overlap. These findings underscore the significance of gender in problematizing ethnic/racial divisions of labor and the need to consider economic consequences that cross these divisions as well as derive from them within urban economies.  相似文献   

20.
Mørch, H., 1975: Population and resources on the minor Danish islands. Geografisk Tidsskrift 74: 21–35. København, juni 1, 1975.

An investigation made on the basis of a simple, linear regression of the relationship between resources—defined as areas after different criteria—and size of population on the minor Danish islands 1860, 1900, and 1960.  相似文献   

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