再论我国耕地的保护和完善保护机制的问题   总被引：2，自引：4，他引：2  

陈朝辉 《热带地理》2002,22(3):253-256

耕地是保证社会经济发展最重要的自然资源，由于耕地必须具备特殊的自然条件。因而决定其数量的有限性，在人多地少的我国，保护好耕地尤为重要，目前我国耕地安全存在严重危机，必须采取有效措施使之得到切实保护，以保证我国社会经济的顺利发展。  相似文献   

Examining the reduction in potable water consumption by households in Catalonia (Spain): Structural and contingent factors     

《Applied geography (Sevenoaks, England)》2017

Water consumption by households is influenced by a host of factors, widely investigated in the literature. However, the effects of contingent situations like drought episodes and economic crises, which may strongly restrict direct water use in households, remain less explored, and especially a combination of both. Catalonia, a Mediterranean region, suffered the worst drought episode in the last 75 years in 2007 and 2008, followed immediately by the worst economic crisis also in several decades between 2009 and 2014 (though still fishtailing). Taking it as a case study and using metered water data for the household sector, we propose a generalized linear mixed model in which the influence of both the drought episode and the economic crisis on per capita water consumption by comarques (supra-municipal entities) is assessed using a drought index on one hand, and economic variables and the water price on the other hand. Likewise, demographic, territorial and climatic determinants, as well as environmental behaviour, are also evaluated. The dataset (N = 287) consists of panel data for the forty-one comarques of Catalonia covering the 2007 to 2013 period. Results confirm that the contingent factors analysed have contributed to further reduce per capita water consumption, being significant the drought index and water price. The proportion of elderly people, the household size and the proxy for environmental behaviour, also have a negative effect on consumption; whereas seasonal population has the expected positive effect. However, neither the climatic and economic variables analysed, nor urban density and the proportion of foreign population, are found to be significant. A better understanding of the factors influencing residential water consumption in a context of growing water scarcity and economic downturn may aid policy makers and water managers not only to improve the effectiveness and efficiency of demand-side management measures that affect households, but to address emerging social concerns such as water poverty.  相似文献   

资源危机型黄金矿山区域构造背景研究——以吉南—辽北地区为例          下载免费PDF全文

吕建生 《地质找矿论丛》2008,23(2):120-124

吉南-辽北地区资源危机型黄金矿山区域构造样式为穹形构造和线性构造已被地质、地球物理和遥感地质所提供的众多信息研究所证明.两种构造样式的区别主要表现在物质组成、构造变形、变质作用、形成时代和对金矿的控制作用等5个方面.  相似文献   

The populist eruption and the urban question     

Ugo Rossi 《Urban geography》2018,39(9):1425-1430

Generalizing the recent experience of the United States, the common wisdom associates today’s ‘populist explosion’ with a deepening urban-rural divide, in which small towns and rural regions are seen as reservoirs of populist anger while large cities in the most prosperous areas are portrayed as strongholds of multicultural coexistence and liberal democracy. In challenging this representation, this paper underlines the ‘urban roots’ of today’s populist phenomenon in Western societies, using Italy as illustrative evidence. It is argued that cities – far from being pacified enclaves of happiness and democracy – are central to the contradictions of contemporary societies and their degenerations, reflecting an ambivalent relationship with the nation-state: potential sites of post-national democracy, on the one hand, but also spaces contributing to the current populist-white-revanchist wave sweeping Western societies, on the other hand. In doing so, the paper shows how the intersected housing and refugee crises have fomented impulses of ethnic-majority revanchism within Italy’s cities and towns in a context of late neoliberalism.  相似文献   

Gentrification and the suburbanization of poverty: changing urban geographies through boom and bust periods     

Cody Hochstenbach  Sako Musterd 《Urban geography》2018,39(1):26-53

Many postindustrial cities across Europe and other contexts are marked by growing social–spatial inequalities, housing liberalization, and gentrification, which limit the housing options of low-income households. We investigated changes in the residential moves of different low-income households (working poor, low-to-middle income, and unemployed) in the Amsterdam and Rotterdam urban regions for the time period 2004–2013. We found an overarching trend for the suburbanization of poverty toward the urban peripheries and surrounding regions. While this trend appears to be relatively crisis resistant in the tight Amsterdam housing context, it is more cyclical in Rotterdam and has slowed following the global financial crisis. Low-to-middle income and unemployed households are increasingly moving to the urban regions surrounding cities, particularly to higher density satellite towns. Nevertheless, a growing number of working poor households remain highly urbanized, employing various coping strategies to acquire housing. This paper reveals how the suburbanization of poverty is both a direct process of poor households moving from city to suburb, and a broader indirect process caused by exclusionary mechanisms such as the decreasing accessibility and affordability of inner-urban neighborhoods, which reflect broader changes in the geography and socioeconomic patterning of urban regions.  相似文献   

对人文科学所遭受抨击的回应     

Iain HAY 《地理科学进展》2018,37(3):317-326

长期以来,不少人站在功利角度,对人文科学进行了颇多抨击。本文意欲对此做出有理有据的反击。首先,文章概述了人文科学在政界、民间和实践领域所遭受的非议,并寻找出主要的批评者及其拥护者。其次,作为申辩内容的一部分,本文详细阐述了人文学科的核心优势。这些优势涵盖了哲学和实用科学领域,包括为知识创造提供批判性视角,使生活丰富多彩,培养应对未来不确定性和复杂性的技能,以及增强理性和维持大学机构的收入和信誉度。最后,本文提出人文学者不仅要开展相关学科里非常重要的理论和实证研究,还必须将捍卫和保护人文科学纳入到专业活动中来。  相似文献   

“Where to put the spare cash?” Subprime urbanization and the geographies of the financial crisis in the Global South     

William Kutz  Julia Lenhardt 《Urban geography》2016,37(6):926-948

This article investigates the geographies of subprime urbanization, and by extension, the displacement of 2007–08 financial crisis to the Global South. Previous research examined the formative ways that technological innovations enabled mortgages to deterritorialize and circulate on secondary markets. Less is known about how cities with underdeveloped financial systems and housing markets have been impacted. The case of Tangier, Morocco, is used to argue that the geography of the crisis must be understood as a particular mode of urbanization, subprime urbanization, predicated upon the creation and exploitation of housing submarkets into new geographical frontiers. Subprime urbanization emerged in Tangier in response to the historic contradictions of regional disinvestment in northern Morocco. Weak financial inclusion for local low-income homebuyers led State bureaucrats to increasingly use housing policy to encourage European investment into Moroccan property markets, thereby transforming policy away from improving homeownership access and inclusion toward an urban model centered on the logics of international property speculation.  相似文献   

Recent achievements on the research of the Paleozoic-Mesozoic transitional period in South China     

Yin Hongfu  Feng Qinglai  Xie Shucheng  Yu Jianxin  He Weihong  Liang Handong  Lai Xulong  Huang Xianyu 《Frontiers of Earth Science》2007,1(2):129-141

This is a review of research achievements on the Permian-Triassic transition in South China. It comprises of five parts: (1) advances on the biostratigraphy and eventostratigraphy of the Meishan Section, the Global Stratotype Section and Point (GSSP) of the Permian-Triassic boundary (PTB); (2) advances on the PTB research of deep water facies, especially the Dongpan Section in Guangxi; (3) advances on the PTB research of terrestrial facies, especially the Chahe Section in Guizhou; (4) correlation of the global change and biotic extinction between the PTB and modern times and its revelation to the status and future of the earth and mankind; and (5) the pattern and causality of the Permian-Triassic extinction. In the last part, it is concluded that the Permian-Triassic transitional interval constitutes a prolonged crisis period ranging from end-Guadalupian extinction to the end of Early Triassic, totaling 14 Ma. The environmental crisis and mass extinction peaked at the PTB, which displayed multiphase extinction rather than just one phase. Commencement of an extinctions prelude prior to the postulated bolide impact implies that the causes of PTB extinction largely lie in the intrinsic developments of the earth, especially those related with the integration of Pangea.  相似文献   

非正常情况下北京城市地质安全危村管理的战略思考     

卫万顺 《城市地质》2007,(4)

为了保证北京城市可持续发展,必须解决可持续发展面临的特殊挑战,有必要进行非正常情况下北京城市地质安全危机管理的战略思考。本文探讨了我市非正常情况下城市地质安全危机管理战略框架,建议制定《非正常情况下城市地质安全危机管理应急预案》和实行定期会商机制,建立完善的苴测预警预报系统,实施城市地质安全保障工程,促进首都经济建设和社会可持续发展。  相似文献   

Precise 40Ar/39Ar dating of volcanic tuffs within the upper Messinian sequences in the Melilla carbonate complex (NE Morocco): implications for the Messinian Salinity Crisis     

Ph. Münch  J.-J. Cornée  G. Féraud  J.-P. Saint Martin  M. Ferrandini  F. Garcia  G. Conesa  S. Roger  M. Moullade 《International Journal of Earth Sciences》2006,95(3):491-503

The Melilla carbonate complex (NE Morocco) is the only area of the Paleo-Mediterranean Sea where volcanic activity was present throughout most of the Messinian. ⁴⁰Ar/³⁹Ar dating of volcanic tuffs interbedded within the upper Messinian sedimentary deposits, known as the Terminal Carbonate Complex (TCC), yields accurate ages of paleoenvironmental and sea-level changes related to the Messinian Salinity Crisis. The new chronologic data (1) provide an average of 5.95–5.99 Ma for the base of the TCC, thus being synchronous with the onset of the Messinian Salinity Crisis, (2) demonstrate for the first time that the basal unconformity of the TCC does not represent a hiatus of long duration, (3) define a precise time line at 5.87±0.02 Ma (2σ) corresponding to sedimentary rocks exhibiting a lateral transition between continental and marine deposits typical of the TCC and (4) yield evidence that emersion of the Melilla platform during deposition of the TCC is partly related to tectono-magmatic activity. An erosional surface, capping the TCC deposits in the Melilla basin, is related to the major Messinian Mediterranean drawdown. The duration of the hiatus, associated with this surface, is estimated to be at most 450 kyr, but is probably shorter.  相似文献