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991.
This paper is situated at the intersections among GIS and geovisualization, critical social theory, and urban studies. It presents an analysis of housing segregation and unequal food and transportation access in Buffalo, New York. We demonstrate how the representation and examination of this socially complex multi-scalar issue benefits from deliberate, reflexive conversation between different critical social-spatial epistemologies. We begin with a relatively simple GIS analysis of spatial segregation and arrive through critical iteration at a more qualitatively nuanced cartogram which moves beyond representations of fixed space to reveal a much more relational situation—a case of “time-space expansion” in which the travel time needed to meet a basic daily need is much greater for the poor and people of color than it is for whiter, more affluent populations. We conclude by infusing this narrative with additional considerations from social theory to show how even a limited visualization such as ours might better critically engage broader social and discursive processes in and across urban space.  相似文献   
992.
北京市建设地下水库的思考   总被引:1,自引:0,他引:1  
为满足城市用水需求,北京市持续超采地下水,使地下水位不断下降,地质环境问题日益突出。地下水库作为一种高效的水资源调控工程措施,对于缓解供水紧张局面具有重要意义。文章分析了在水资源短缺以及南水北调工程即将通水形势下,北京建设地下水库的必要性,阐述了北京市地下水库的研究基础,讨论了地下水库的建设条件和工作方法,并对地下水库运行管理提出需要关注的问题,为北京市研究建设地下水库提供参考。  相似文献   
993.
The morphology of the Yangtze Estuary has changed substantially at decadal time scales in response to natural processes, local human interference and reduced sediment supply. Due to its high sediment load, the morphodynamic response time of the estuary is short, providing a valuable semi-natural system to evaluate large-scale estuarine morphodynamic responses to interference. Previous studies primarily addressed local morphologic changes within the estuary, but since an overall sediment balance is missing, it remains unclear whether the estuary as a whole has shifted from sedimentation to erosion in response to reduced riverine sediment supply (e.g. resulting from construction of the Three Gorges Dam). In this paper we examine the morphological changes of two large shoals in the mouth zone (i.e. the Hengsha flat and the Jiuduan shoal) using bathymetric data collected between 1953 and 2016 and a series of satellite images. We observe that the two shoals accreted at different rates before 2010 but reverted to erosion thereafter. Human activities such as dredging and dumping contribute to erosion, masking the impacts of sediment source reduction. The effects of local human intervention (such as the construction of a navigation channel) are instantaneous and are likely to have already resulted in new dynamic equilibrium conditions. The morphodynamic response time of the mouth zone to riverine sediment decrease is further suggested to be >30 years (starting from the mid-1980s). Accounting for the different adaptation time scales of various human activities is essential when interpreting morphodynamic changes in large-scale estuaries and deltas. © 2019 John Wiley & Sons, Ltd.  相似文献   
994.
冀西石湖金矿矿体赋存规律及深边部找矿前景   总被引:1,自引:0,他引:1  
在分析成矿地质背景和矿区地质特征的基础上,提出了石湖金矿区断裂破碎带赋存工业矿体的条件,总结了矿体矿化富集规律和产出特征,利用包裹体测温方法进行了矿体侧伏规律的研究.基于金矿体赋存规律的研究,并结合EH-4勘查技术,提出在101矿带深部和南部具有很好的找矿前景.  相似文献   
995.
对天津王3井逸出氦气浓度日变化和年变化特征进行了分析,结果表明:①王3井逸出氦气浓度日变幅背景值在0.0012%—0.0036%之间,日变幅在冬季偏高;②在大多数观测日的10—18时左右,王3井逸出氦气浓度日变化曲线有“波谷”,但没有明显的“波峰”,但在部分观测日逸出氦气浓度日变化曲线的“波谷”却不明显,王3井逸出氦气浓度日变化形态不属于“固体潮”型;③王3井逸出氦气浓度年变化曲线呈上升的“双峰双谷”似“潮汐”形态,一般在6月、12月左右出现“波峰”,3月、9月左右出现“波谷”,相比较而言,“波峰”更显著。通过对井孔所在地的地质构造、大气温度、降水、同井孔水位、周边地热资源开采等因素的分析,笔者认为王3井逸出氦气浓度的变化基本不受大气温度、降水和同井孔水位变化的影响,主要与井孔所在地的断层活动性和周边地热资源的开采有关。  相似文献   
996.
北京西山隆起区没有天然温泉出露。近年来,在谷积山背斜相继钻井发现了40~49℃的地下热水,但对地热系统成因尚无研究。运用地质、水文地质、地球化学等方法开展研究,结果表明热储为蓟县系雾迷山组白云岩岩溶裂隙水,热水为HCO_3-Ca·Mg型,为中-弱碱性、微硬度、氟水型淡热矿水,初步称为北京西山谷积山地热田。构建了地热系统成因模式,分析热源为谷积山背斜深部隐伏的燕山期酸性花岗岩体产生的放射性元素衰变生热,为隆起山地碳酸盐岩层状热储的地热系统类型,不同于一般隆起山地导热断裂对流地热系统类型。结合西山地区广泛发育的穹窿型构造与燕山期岩浆活动特征,初步预测西山下苇甸穹窿等穹窿型构造具有形成地热系统的地热地质条件,有潜力成为地热资源的富集远景区。  相似文献   
997.
由火山喷发、岩浆侵入或陨石撞击作用所形成的环形构造,是地球物质活化迁移的重要场所,对区域成矿过程具有极大的制约意义。在河北省西北部坝上地区,围绕沽源县城一带,早白垩世岩浆岩、布格重力异常及水系沉积物地球化学异常均呈现明显的多级环带分布。这种现象并非尚义-崇礼-赤城深大断裂与乌龙沟-上黄旗岩浆岩带的简单复合叠置,而是以沽源为中心的火山机构的具体表现。该环形构造至少可划分为三个岩浆岩环带,分布着早白垩世(K—Ar100~123Ma)安山质火山-沉积岩和燕山旋回第四期(K—Ar100~138Ma)次粗面岩、次安山岩、二长斑岩、石英正长斑岩等浅成超浅成侵入岩体或岩株,它们的银、铅、锌、镉、铀、钍、钼、砷、锑等元素显著活化和富集。该环形构造控制着蔡家营铅锌矿、张麻井铀钼矿、彭家沟银矿、青羊沟铅锌矿、牛圈银金矿及北岔沟门铅锌银矿的时空定位。若干迹象表明,沽源环形构造可能是白垩纪时期一次陨击事件(因火星和木星之间两颗小行星的碰撞)的结果,这也许是中生代成矿大爆炸的根本诱发机制。  相似文献   
998.
在河北省铁矿资源潜力评价及成矿预测中,对重力场、磁场特征进行了总结和归纳,认为规模较大的航磁正异常主要是出露或隐伏侵入岩基的反映;大面积分布的低缓正磁异常区则主要反映了太古宙变质岩系或基底隆起的边缘,沉积变质型铁矿主要密集分布在此区域;负磁场区主要出现在中上元古界、古生界碳酸盐岩和中生界酸性火山—沉积岩系;强度高、梯度大、或有明显负值伴生的局部磁异常则可能是磁性铁矿的反映。从重力场特征看,磁性铁矿主要分布在布格重力异常的梯级带或异常扭曲处,以及正、负异常的交界处,这些地方多与地质构造强烈变形密切相关。只有对重磁场进行深入地质剖析,结合典型矿床上建立的识别标志进行对比分析,才能得出一个符合客观实际的地质解释。  相似文献   
999.
The Pliocene to possibly Pleistocene uppermost Orubadi and Era Formations, southwest margin of the Papuan Peninsula, are interpreted as having been deposited in alluvial-fan, fan-delta and shallow-marine environments. The alluvial-fan facies consists primarily of lenticular, coarse-grained conglomerate (up to 2 m boulders) and cross-bedded and horizontally laminated sandstone. Conglomerate and sandstone were deposited in shallow fluvial channels and by overbank sheetfloods. The facies also contains thick mudflow diamictite and minor tuff and terrestrial mudstone. The shallow-marine and fan-delta facies, in contrast, consists of heterogeneously interbedded marine and terrestrial mudstone, sandstone, diamictite, conglomerate and limestone. Marine mudstone is calcareous, sandy, bioturbated, and contains marine shells. Limestone is mostly packstone that has a varied, open-marine fauna. Rare coral boundstone is also present. Marine sandstone is burrowed to bioturbated and is hummocky cross-stratified in places. Some marine mudstone contains sandstone pillows formed by loading of unconsolidated sand by storm waves. Other sandstone in the fan-delta facies is cross-bedded, lacks shells and was probably deposited by fluvial processes. Several conglomerate beds in the fan-delta facies are well sorted and imbricated and were also deposited by stream floods. The synorogenic Orubadi and Era Formations were deposited in a foreland basin formed from loading of the Papuan–Aure Fold and Thrust Belt on the edge of the Australian craton. Deformation in the fold and thrust belt was probably related to docking and compression of the Finisterre Terrane–Bismarck Arc against the New Guinea Orogen. The Era Formation interfingers with the reefal Wedge Hill Limestone in which reef facies likely grew on a deforming anticline. Era Formation siliciclastics were sourced from volcanic, metamorphic and sedimentary rocks that were uplifted in the orogen to the northeast. Volcanic sediment was derived mostly from a then-active volcanic arc likely related to southward subduction at the Trobriand Trough.  相似文献   
1000.
该文对河北省现代化目标,即“世界中等发达国家水平”进行理论界定,对河北省现代化实现程度进行综合评估。研究表明,河北省传统工业化时代的现代化实现程度已达到68.70%,略低于全国平均水平(72.30%),表明河北省已经在传统工业化道路上走过了三分之二的路程;河北省相对于当代世界中等发达国家水平的实现程度为40.39%,接近于全国平均水平(42.15%)。提出构筑河北省创新体系,加速河北省现代化进程的若干政策建议。  相似文献   
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