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71.
The Zhujiang (Pearl) River Delta is one of the most developed Extended Metropolitan Regions (EMR) in China.With the rapid urbanization,the agglomeration of population and industries has emerged,which has led to dramatic changes of spatial structure and land use in this region.With data of high resolution TM remote sensing images and Google Earth maps,this paper identified and analyzed the spatial pattern of the Zhujiang River Delta EMR using Envy and ArcGIS tools.It was found that 1) the industrial land uses were expanding substantially,particularly on the bank sides of the Zhujiang River estuary;2) large-scale housing developments were concentrated in the fringe of metropolitan areas such as those of Guangzhou and Shenzhen;3) a regional transportation network with the spatial pattern of ″1 circle +2 pieces + 3 axes″ had significantly affected the location choice of manufacture enterprises.At the same time,both highly specialized land use and severely mixed land use patterns were identified.As a consequence of the latter,land use efficiency of the whole EMR areas was reduced.Moreover,ecologic and environmental problems were severe.Based on the above analysis,suggestions were given from the viewpoint of spatial safety,land use efficiency,and the reorganization of spatial structure in the Zhujiang River Delta EMR.  相似文献   
72.
盐水沟北铜矿区位于新疆库车县北部,其大地构造位置处于塔吉克-塔里木陆块区、塔里木陆块、塔里木北缘隆起、库车前陆盆地,区内构造活动强烈。铜矿床赋存于新近纪中新统康村组第一岩性段,矿体呈层状,严格受地层控制。区内共圈定10个铜矿体,矿石矿物主要为孔雀石、赤铜矿、水胆矾、自然铜等,矿体内无夹石,顶、底板围岩均为褐红色及浅红色粉质泥岩。该矿床为砂岩型铜矿床。  相似文献   
73.
云南城市经济影响区空间组织演变规律   总被引:4,自引:0,他引:4  
吴启焰  陈浩 《地理学报》2007,62(12):1244-1252
对1990-2004 年云南省城镇发展差异进行分析,发现自20 世纪90 年代以来云南省城市综合实力总体呈差异扩大的趋势,表现出小城市发展缓慢且分化不明显,少数高位城市极化,在空间呈现明显的核心-边缘倾向等特征。其后,进一步展示云南省城市经济影响区空 间演化的阶段性规律:① 20 世纪90 年代以前云南省城市经济影响区被特殊的地理环境分割 成破碎且难以整合的小型离散化的格局;② 自20 世纪90 年代以来,随着地区工业化和城市 化加速进行,交通通讯网络的发育和辐射,中小城市得以发育,伴随于城市经济影响区空间 扩张与收缩,云南省城市经济影响区逐渐从单层离散分布演变为三层嵌套结构,并不断朝更高级的结构形态演进,即云南省城市经济影响区空间呈现显著的、由小规模离散分布阶段、过渡转型阶段到嵌套复合阶段的时空演化序列。最后,针对这种时空演化序列,笔者解析出云南省城市经济影响区在不同时空条件组合下的三种空间扩展类型:单向拓展类型、多向拓展类型和邻接扩展类型。  相似文献   
74.
This paper quantitatively explores farmers' vulnerability to flood in the Poyang Lake Region (PLR) with the supports of GIS spatial functions. The analysis consists of three major steps,which is based on the spatial unit of township. Firstly,the spatial extent and charac-teristics of flood risk areas were determined using a digital elevation model (DEM) derived from the 1:50,000 topographic map. Secondly,for each of the township,six indices indicating the economic activities of local farmers were calculated. These indices are: rural population proportion,cultivated land proportion,GDP per unit area,employment proportion of primary industry,net rural income per capita and agricultural income proportion. These six indices were then normalized and used for later vulnerability assessment. Thirdly,the normalized indices (as GIS data layers) were overlaid with the flood risk areas to produce the risk coeffi-cient for each township and to calculate the overall vulnerability for each township. The analysis results show that in the PLR there are high flood risk areas where the farmers' livings are seriously influenced or threatened. About 55.56% of the total 180 townships in the flood risk areas have a high degree of flood vulnerability. The townships under flood risk are mainly distributed in the areas around the Poyang Lake and the areas along the "five rivers".  相似文献   
75.
Wang  Zhenbo  Li  Jiaxin  Liang  Longwu 《地理学报(英文版)》2021,31(2):245-264
The cultivation and development of modern metropolitan areas with the aim of establishing new regional centers with competitive edge is a key objective for the new-type urbanization directions in China. The construction of the Lhasa Metropolitan Area is of great significance for the promotion of the South Asia Channel, the ‘Belt and Road' initiative, the Bangladesh-China-India-Myanmar Economic Corridor, the Himalaya Economic Cooperation Zone, and for rapid development and long-term stability of the Qinghai-Tibet Plateau. This paper examines the scope of the Lhasa Metropolitan Area including Chengguanqu(Chengguan District), Doilungdeqen, Dagze, Lhunzhub, Damxung, Nyemo, Quxu, Maizhokunggar, Samzhubze Qu(Samzhubze District), Gyangze, Rinbung, Bainang, Nedong, Gonggar, and Zhanang using a spatial field energy model that combines nodality and accessibility indices and considers multiple indicators including traffic flow between cities. By combining factors such as the natural background, population agglomeration, the social economy, infrastructure construction, and the urban spatial structure of the Lhasa Metropolitan Area, it is proposed to build a bow-and-arrow-shaped urban system with ‘one core, two centers, one axis, and two wings' along the valleys and the transportation trunk lines of the area. The study advocates the construction of a pure land industrial system comprising a green cultural and tourism-oriented plateau.  相似文献   
76.
Reaction and deformation microfabrics provide key information to understand the thermodynamic and kinetic controls of tectono‐metamorphic processes, however, they are usually analysed in two dimensions, omitting important information regarding the third spatial dimension. We applied synchrotron‐based X‐ray microtomography to document the evolution of a pristine olivine gabbro into a deformed omphacite–garnet eclogite in four dimensions, where the 4th dimension is represented by the degree of strain. In the investigated samples, which cover a strain gradient into a shear zone from the Western Gneiss Region (Norway), we focused on the spatial transformation of garnet coronas into elongated garnet clusters with increasing strain. The microtomographic data allowed quantification of garnet volume, shape and spatial arrangement evolution with increasing strain. The microtomographic observations were combined with light microscope and backscatter electron images as well as electron microprobe (EMPA) and electron backscatter diffraction (EBSD) analysis to correlate mineral composition and orientation data with the X‐ray absorption signal of the same mineral grains. With increasing deformation, the garnet volume almost triples. In the low‐strain domain, garnet grains form a well interconnected large garnet aggregate that develops throughout the entire sample. We also observed that garnet coronas in the gabbros never completely encapsulate olivine grains. In the most highly deformed eclogites, the oblate shapes of garnet clusters reflect a deformational origin of the microfabrics. We interpret the aligned garnet aggregates to direct synkinematic fluid flow, and consequently influence the transport of dissolved chemical components. EBSD analyses reveal that garnet shows a near‐random crystal preferred orientation that testifies no evidence for crystal plasticity. There is, however evidence for minor fracturing, neo‐nucleation and overgrowth. Microprobe chemical analysis revealed that garnet compositions progressively equilibrate to eclogite facies, becoming more almandine‐rich. We interpret these observations as pointing to a mechanical disintegration of the garnet coronas during strain localization, and their rearrangement into individual garnet clusters through a combination of garnet coalescence and overgrowth while the rock was deforming.  相似文献   
77.
Two crust-forming events dominate the Precambrian history of the Western Gneiss Region (WGR) at about 1800–1600 Ma and 1550–1400 Ma. The influence of the Sveconorwegian orogeny (1200–900 Ma) is restricted to the region south of Moldefjord-Romsdalen. A series of anorthosites and related intrusives are present, possibly derived from the now-lost western margin of the Baltic craton that may have been emplaced in the WGR as an allochthonous unit before the Ordovician.The Caledonian development is split into two orogenic phases, the Finnmarkian (Cambrian — Early Ordovician) and the Scandian (Late Ordovician/Early Silurian — Devonian). The lower tectonic units west of the Trondheim Trough may be Finnmarkian nappes ; they were part of the lower plate during the Scandian continental collision. The Blåhö nappe is correlated with dismembered eclogite bodies along the coast. A regional change of nappe transport direction from 090 to 135 marks the initiation of an orogen-parallel sinistral shear component around 425 Ma. The change caused the development of a complex sinistral strike-slip system in the Trondheim region consisting of the Möre-Tröndelag Fault Zone and the Gränse contact. The latter cut the crust underneath the already emplaced Trondheim Nappe Complex, thus triggering the intrusion of the Fongen-Hyllingen igneous complex, and initiating subsidence of the Trondheim Trough, and was subsequently turned from a strike-slip zone into an extensional fault. Minor southward transport of the Trondheim Nappe Complex rejuvenated some thrusts between the Lower and the Middle Allochthon. A seismic reflector underneath the WGR is interpreted to be a blind thrust which subcrops into the Faltungsgraben. During Middle Devonian orogenic collapse, detachment faulting brought higher units, now eroded elsewhere, down to the present outcrop level, such as the Bergen and Dalsfjord nappe and the Old Red basins.  相似文献   
78.
三峡地区水资源评价   总被引:1,自引:0,他引:1  
赵海瑞  储开凤 《水文》1995,(3):12-19
在大量水文资料统计分析的基础上,对三峡地区主要水文要素的时空分布及变化特征、分区水资源的评价和开发利用条件进行了系统分析,可为三峡工程建设提供该地区社会经济发展的科学依据和基本的水文水资源数据。  相似文献   
79.
本文以湖北大别山区为例,提出了自然条件复杂,资料缺乏的山区土地资源第一性生产力的估算方法,并计算了湖北大别山区土地资源的生产力。即在土地资源带及类型(组合)区划分的基础上,以资源类型(组合)区为基本单元,通过典型地区抽样获取资料,运用多种数学模型测算,并经过综合判定,求得各类型(组合)区,资源带主要作物的第一性生产力。  相似文献   
80.
采用气候学方法,计算了祁连山北坡不同海拔处的年降水量和乔木林年蒸散量,据此确定了满足乔木林需水的高度带。分析所得的7月均温10℃和6℃,可分别作为乔木林和灌木林生长的温度下限指标。据祁连山北坡水热条件的分布特点,确定了海拔2500—3200米处适宜发展乔木林,其生长以海拔2700—2900米处为最佳,海拔3200—3700米处适宜发展灌木林,其余山区只能生长草类。  相似文献   
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