荒漠灌丛微生境土壤温度的时空变异特征——灌丛与降水的影响   总被引：2，自引：1，他引：1  

张亚峰  王新平  虎瑞  潘颜霞 《中国沙漠》2013,33(2):536-542

对干旱区优势固沙灌木柠条群落不同微生境（灌丛外和灌丛下）的土壤温度（0 cm、5 cm、10 cm和20 cm剖面深度）进行了连续测定,对比分析了晴天、降水日与灌丛对其微生境土壤温度时空变异的影响。结果表明:降水和植被灌丛对土壤温度均具有显著影响。在无雨日,受灌丛遮阴影响,灌丛外土壤温度明显高于灌丛下相同深度的土壤温度;在降水日,土壤温度主要受降水影响,降水使土壤温度明显降低,灌丛的影响作用减弱,灌丛下和灌丛外同一剖面深度的土壤温度差异较小。无雨日土壤温度日变化呈单峰型正弦曲线,随剖面深度增加,土壤温度振幅逐渐减小,峰值出现时间滞后,土壤温度垂直分布变化呈现4种典型变化曲线。夜间（日落至日出）柠条灌丛下地表温度（0 cm土壤温度）比灌丛外地表温度略高。降水日土壤温度日变化随降水过程的持续呈逐渐递减趋势,土壤温度垂直分布变化表现为随深度增加而递增的趋势。  相似文献   

北京城市公共绿地对房地产价值的影响研究(英文)     

张彪  谢高地  夏宾  张灿强 《资源与生态学报(英文版)》2012,(3):243-252

欧美地区大量研究表明,城市公园对附近房地产价值有明显增值效应,但是关于北京城市绿地与房地产价值之间的关系还未有研究,阻碍了社会公众和城市管理者对绿地资源重要功能的认识。本研究首先采用问卷调查与享乐价格法,分析了北京城区14个公园绿地与附近76个居住小区房产价格的关系,并借助北京市第七次园林绿化资源普查数据(2009)与GIS技术测算了18070ha城市公共绿地的房产增值总效应。结果表明,在北京地区,公园绿地能对其附近850-1604 m范围的房产价格有0.5%-14.1%的增值效应。北京城市公共绿地共产生28.6亿元的房产增值, 约合每公顷绿地平均增值16万元, 相当于绿地维护成本的1.8-3.9倍。因此,通过提高绿地附近房产的部分税收作为绿地建设与维护资金具有一定的现实意义。  相似文献   

火山岩油气储层特征浅析   总被引：21，自引：0，他引：21  

张新荣  王东坡 《世界地质》2001,20(3):272-278

火山岩储层是一种特殊的油气储层.火山岩储层的发育在很大程度上依赖于储层的岩性岩相特征,主要为玄武岩、安山岩、以及自碎角砾熔岩,包括爆发相、溢流相、次火山岩相、火山通道相、侵入相和喷发沉积相.火山岩主要靠相互连通的孔、洞、缝组成的网络来构成储集空间.储集空间有原生和次生两大类.我国中-新生代玄武岩储层的测井曲线特征一般是低声波,低感应,低自然伽码,高电阻,高密度;在地震剖面上多表现为低频的强反射,层速度为2 500～5 000 m/s.  相似文献   

Imagining the border and Southern spaces: Cinematic explorations of race and gender     

Susan P. Mains 《GeoJournal》2004,59(4):253-264

For some time the US-Mexico border has been a symbol – and site – of conflict, collaboration, and transnational mobility. Related to the border, the topic of undocumented immigration, and Mexican migrants in particular, has received considerable attention in US mainstream media. Cinema in particular, provides a context for producing and interrogating discourses of nationalism, nativism, and fear. The cinematic examples I draw on illustrate an ongoing fear (and terror) about borders and border crossing of various forms. In this paper I explore how narratives of borders and nationhood are mapped onto immigrant bodies and border spaces through specific filmic representations. In order to undertake this study I focus on three cinematic examples exploring immigration at the US-Mexico border – Touch of Evil, The Border and Lone Star. I examine how concepts of borders, race, and gender, and tropes of ‘The South’ are reterritorialized around immigrant bodies and specific locales. I argue that an inability to control and ‘fix’ boundaries around possible ‘threats’ to specific US spaces and identities is counteracted by displacing this fear onto more easily marked targets that are viewed as posing challenges to US national (and personal) security, i.e., undocumented immigrants. At the same time, cinematic images illustrate that the threats and spaces for immigrants themselves become increasingly marginalized, blurred, and frequently erased. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Lowland Canterbury landscapes in the making     

Eric Pawson  Peter Holland 《New Zealand geographer》2005,61(2):167-175

Abstract: This article explores environmental imaginaries of colonization in lowland Canterbury. In 1844 Edward Shortland observed that his Māori companions had an exceptionally detailed geographical knowledge of the area and its resources, yet a few years later European settlers were viewing it as an empty stage on which to envision newly‐constructed landscapes. The terrain was contested, but colonial ‘improvement’, through the creation of spaces of modernity, took no cognizance of this. The legacies of that transformation are a simplified, orderly landscape, and fractured but persistent memories of indigenous ecosystems that are now being revived.  相似文献   

GLOBALIZATION AND EXTERRITORIALITY IN METROPOLITAN CAIRO     

PETRA KUPPINGER 《Geographical review》2005,95(3):348-372

ABSTRACT. Rapid construction of new spaces like hotels, malls, private clubs, and gated communities in Greater Cairo, Egypt produces structures disconnected spatially and conceptually from most of the existing urban fabric. Their spatial concepts and practices, as well as architectural forms and expertise, are based largely on globally available models. Planning and construction are guided by the search for security in the face of real or imagined fear of the urban masses and political upheaval. Concrete walls, guarded entrances, and high‐tech security technology bear witness to these fears. Analysis of the Mena House Hotel, the Grand Egyptian Museum project, and the First Mall in Giza shows how these projects globalize Cairo and localize the global. Often these globalized spaces are remade by creating local and regional ties and design features that were not anticipated by the planners. Such changes shed light on underlying dynamics and contribute to a better understanding of in situ globalization. Whereas their physical features tend to accentuate their globalized nature, these spaces do not exist in isolation from their geographical and cultural contexts. Their everyday realities tell tales of reterritorialization that are frequently overlooked in scholarly debates.  相似文献   

Contextualising gender empowerment at the grassroots: a tale of two policy initiatives     

Saraswati Raju 《GeoJournal》2006,65(4):287-300

The policy environment on gender is fraught with contradictions and contestation of varying degrees in India that does not disappear even as recent transformative mode of participatory initiatives seem to place women’s agency at the core of empowerment agenda. Drawing from two collaborative projects at the grassroots, the paper argues that even well conceptualised projects miss the cutting edge distinction between women and gender and continue to engage with an instrumental logic of women’s development and empowerment at the expense of issues of gender equality and equity in translating the intention into action. It is also observed, however, that spatially embedded social and cultural specificities impact policy discourse resulting in very different outcomes of conceptually comparable policy formulations. According to the author acknowledging spatiality of experiences provides a vantage point to critically engage with context-specific strategies to resolve gendered conflicts and tensions resulting from confining social relations and normative gender codes.  相似文献   

Urban green resilience: Experience from post-industrial cities in Poland     

《地学前缘(英文版)》2023,14(4):101560

De-industrialisation triggered economic, spatial and environmental changes in cities. Therefore, this study identifies whether there has been a reorientation of spatial development in post-industrial cities towards the creation of green spaces. The aim of the study is to analyse and evaluate the transformation of green spaces in 32 major cities in Poland, including 12 post-industrial cities. Data sources were vector land cover data models from the Urban Atlas for 2006 and 2018, administrative boundaries from the National Boundary Register and building layers from the Topographic Objects Database. The research procedure was carried out using the GIS environment, through spatial analysis, geoprocessing algorithms, and spatial statistics. The results have shown that post-industrial cities do not develop their urban resilience based on the expansion of green spaces and, consequently, do not build green urban resilience. In addition, the research has proven that the greatest loss of green spaces is noticeable in parts of post-industrial cities with medium and high development intensity, where there is an intensification of construction activity. The dominant direction of the transformation of green spaces has been the conversion of agricultural areas into green spaces (87.79%). In contrast, the main direction of loss in green space has been the creation of new industrial units (24.80%) and the expansion of the urban fabric (23.53%). The article is original due to the fact that there is a gap in the literature regarding the study of green spaces in post-industrial cities with regard to the concept of green urban resilience.  相似文献   

Embracing Informality – A Commentary     

Liora Bigon  Ambe J. Njoh 《The Cartographic journal》2017,54(2):181-184

This short commentary surveys an international exhibition entitled ‘The cartography of the unseen’, presented at HIT's Faculty of Design Research Gallery, Israel, February 2015. For a better understanding of this exhibition and its implications, also theoretically, we intervened with a further interpretation on one of the exhibited projects, that is, Map Kibera.  相似文献   

近40a黄河流域国土空间格局变化特征与形成机理   总被引：3，自引：0，他引：3  

宋永永  薛东前  夏四友  米文宝 《地理研究》2021,40(5):1445-1463

科学认知黄河流域国土空间格局变化过程与影响因素,是构建可持续国土空间开发保护格局,实现黄河流域高质量发展的迫切需要。本文采用国土空间转移矩阵、标准差椭圆和地理探测器方法,研究1980—2018年黄河流域国土空间格局变化特征与形成机理。研究表明：① 近40a黄河流域国土空间具有明显的水平地域差异和垂直梯度分异特征,生产空间持续减小,生活空间不断扩大,生态空间占绝对主体地位,但呈现波动变化态势。② 黄河流域国土空间格局变化逐渐加快,地区差异性和空间指向性更加明显。农业生产空间减小地区与林地、草地和其他生态空间增加地区具有空间协同关系。③ 年平均气温对生产空间的影响程度显著增强,海拔高度对生活空间和生态空间的约束作用逐渐增强;人口密度和固定资产投资规模对生产空间和生活空间演化影响广泛,城镇化率和生态环境保护政策对生态空间演化影响深刻。④ 黄河流域宏观的自然本底是当前国土空间开发保护格局形成的重要地理基础;城镇化、工业化及生态保护与建设政策是国土空间格局演化的关键动力,加速了黄河流域国土空间格局变化进程;各自然因子与人文因子交互作用对国土空间格局演化具有非线性增强效应和双因子增强效应。  相似文献