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1.
A major glacial-lake outburst flood in the Glomma valley, south-eastern Norway, took place during the final decay of the Scandinavian Ice Sheet. A combined morphological, geophysical and sedimentological study provides new insight into the variety of processes and deposits of the flood. The studied succession, some tens of metres in thickness, comprises the fill of a major flood basin that developed during hydraulic ponding. Large-scale sand dunes and bars accumulated downstream of locations with expanding flow. Most notable are 10 m high, concentric dune ridges that accumulated downstream of a topographical constriction hosting a high-velocity flow. Flow expansion at the outlet generated intense turbulence and scouring. The sand-loaded eddies helped feeding the semi-stationary dune ridges that grew vertically and downflow under high aggradation rates. Internal structures vary but reflect an overall shift in sedimentation from prevailing supercritical flow to overall subcritical flow conditions at high flood levels. Loading by water and sediment caused large-scale, synsedimentary deformation, increasing local accommodation space. Fast-falling flood levels caused stronger flow locally, while mud and fine sand settled in stagnant pools. The fall caused a significant drop in hydrostatic pressure. This triggered a release of excess pore pressure causing massive dewatering and fluidisation. Water-escape structures include numerous (sub)vertical pipes. The present study shows that outburst flood-generated, large-scale dunes can develop in well-sorted, fine sand and are thereby easily confused with aeolian deposits. Several dune fields in south-eastern Norway are here reinterpreted as the product of at least two major flood events. Sandy dune fields with similar characteristics elsewhere in Scandinavia should likely also be reinterpreted, and the role of outburst floods during the final deglaciation of Scandinavia has seemingly been underestimated. The study emphasises the importance of ponding, flow expansion, sorting, rapidly changing pressure conditions and deformation for outburst flood-related sedimentation.  相似文献   

2.
This paper provides an in-depth analysis of community gardens in a (post)socialist setting during a time of key changes in their perception and management. Community gardens in Zagreb emerged in two specific economic and socio-cultural contexts and a diachronous approach to the study of urban gardens offers a unique insight into differences and similarities reflecting and contrasting those periods. Semi-structured interviews and non-participatory observation were employed. Results show that community gardens in Zagreb are multilayered places which satisfy diverse needs of the urban residents, including home grown food, socializing, recreation, contact with the nature, and supplementation for low pensions. They can also be seen as examples of heterotopias or alternative spaces during both examined periods. In the socialist period they were secluded, private, pseudo-rural places in a semi-authoritarian, communal, and (supposedly) urban and industrial society. In post-socialist Zagreb, characterized by an uncontrolled and unplanned spatial context reliant on neoliberal market-oriented principles, social insensitivity and exclusion, the new gardens are depicted as beacons of communal involvement, grassroots movements, and the ability of citizens to stand together and make their voices heard.  相似文献   

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The recent emergence of the Fairtrade certification of gold in Latin America and sub-Saharan Africa promises a radical new direction for the environmental governance of artisanal and small-scale mining (ASM). In doing so, it aims to tackle the longstanding environment and development challenges of the sector which mainstream policy has failed to alleviate. The move towards more responsible ASM practices is premised on the strategic deployment of a Fair Trade discourse that argues for its operators to be recognized not as criminals, but as valued and formalized parts of their broader economies. It is argued in this paper that this development intervention should be read within a social and environmental justice framework, one which directly answers the call from political geography for ‘compelling accounts’ of positive representations of the sector.Through a discourse analysis of 10 years of media reports, interviews and recorded life histories of key ASM and Fair Trade stakeholders in Tanzania, it shows how three strands of justice (conceptualized in terms of fairer distribution, procedure and recognition) are articulated by the Fair Trade gold movement and critically assesses the politics behind such a deliberate strategy. In particular, it argues that recognition is a key part of justice that has been underplayed by erstwhile analyses of Fair Trade. Through a case study of Tanzania, it is concluded that although significant progress has been made in terms of arguing for greater recognition for ASM operators, there remains a need to better link discourse with practice in establishing greater distributional justice.  相似文献   

5.
Tanja R. Müller 《Geoforum》2012,43(4):793-803
This paper discusses Eritrea as a contemporary case of state-making grounded in war, a fact that has resulted in the emergence of one of the ‘hardest’ states in sub-Saharan Africa. The state-making process in Eritrea is looked at with a focus on the legacies of liberation movement governance in the changing dynamics of state consolidation from 1993 to this day. Those dynamics are analysed by reverting to Hirsch-man’s categories of ‘loyalty’, ‘exit’ and ‘voice’. Hirschman’s framework is chosen because the category of loyalty and resulting dynamics illuminate particularly well the transitions within the Eritrean state making process.It is shown that the parameters of war that have resulted in the creation of the Eritrean state have led to a particular kind of state characterised by a high degree of loyalty, visible in the propensity of large segments of the population to associate with state activities. Over time and partly based on military defeat in renewed warfare, the exit option has gained prominence particular among the young generation. This has resulted in a drive towards state securitisation combined with measures to make exit a pillar of power consolidation. Those dynamics have not considerably altered the loyalty of Eritrea’s transnational citizenry to the wider project of state consolidation. The paper concludes that state consolidation in Eritrea can thus far be analysed as a successful shift from fostering voice via politics of mobilisation to controlling exit and voice in ways that keep citizens tied to the state project.  相似文献   

6.
With independence in 1991, Uzbekistan, as most of Central Asia, entered into a phase of socio-economic transformation. In agriculture, this state-driven restructuring of the former system has concentrated on the ‘formal’ sphere of land and water governance.This paper assesses water management in Khorezm, Uzbekistan, taking a social constructivist and boundary work-inspired perspective. Several limitations to effective water management in Khorezm exist. We argue that three types of practices are widely employed to manage these and assure water access: formal, strategic, and discursive practices. The discrepancy between the formal water management institutions, manifested and regulated through formal practices and the informal, widely pursued through strategic practices and acts of deviation, is overcome through discursive practices. Verbal references to formal institutions therefore hamper the formalizing of informal practices. The institutionalized employment of all three types of practices fosters the production and reproduction of boundaries demarcating two, largely separate, spheres of reality in Khorezm’s water management. Consequently, a high degree of resistance to the integration of informal water management realities into the formal regulatory environment prevails, preventing mutual learning and thus the locally informed restructuring towards more efficient and sustainable water management in Khorezm.  相似文献   

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《International Geology Review》2012,54(16):2057-2079
ABSTRACT

In southern Egypt, Neoproterozoic granitoids intrude the crust from Libya in the west to the Nile River in the east. Best exposed at Gebel Uweinat, Gebel Kamil, Bir Safsaf, Gebel El Asr and Gebel Umm Shaghir, these rocks represent the transition between the rejuvenated Archean to Paleoproterozoic crust of the east Saharan craton and the juvenile Neoproterozoic crust of the Arabian–Nubian Shield to the east. We present U-Pb zircon geochronology and whole rock geochemistry from 16 Neoproterozoic (c. 628–580 Ma) granitoids across southern Egypt which document the synchronous production of diverse compositions indicative of an intraplate or intracontinental tectonic setting. Our data better constrain the age relationships, petrogenesis, and Pan-African crustal growth associated with the amalgamation of Gondwana and contribute to understanding the crust-modifying processes that led to the development of the Saharan metacraton in the Ediacaran.  相似文献   

9.
This study identifies the coping and adaptation behavior of the farm households and also examines the factors that influence farmers’ choice for drought-induced adaptation strategies. The study employs a multivariate probit model on 215 farm households’ survey data from northwest Balochistan, Pakistan. The findings reveal that the farmers have shown considerable fortitude in coping with the impacts of drought on their agro-based practices and employed several adaptation initiatives both at on-farm and off-farm levels. These include crop management, water management, adjustment in agricultural inputs, income diversification, economization of expenditure and consumption smoothing, migrating to other places to seek alternative sources of income, assets depletion, and borrowing. Empirically, it is depicted that landholding, annual income, livestock ownership, credit access, farmer-to-farmer extension, GOs/NGOs support increase the probability of farmers’ decision to cope and adapt better with drought hazard. This study implies for specific policy and practice-oriented solutions in order to cope with and adapt in drought situation.  相似文献   

10.
Angus Cameron 《Geoforum》2012,43(4):741-749
This paper argues that the metaphorical figure of the island plays an important but profoundly ambiguous role in the imagination of social space. The paper argues that ‘utopic’ islands have historically provided a fictional domain of experimentation that has informed the constitution of ‘real’ state spaces. From the 16th to 20th centuries this took the form of an increasingly consolidated and ‘global’ endotopia: a world, exemplified by the ‘political’ map, full of state spaces constituted as interiors. More recently, islands have served a very different metaphoric function, being used to create and legitimise spaces of exteriority – ‘xenospaces’ such as the online worlds of the ‘metaverse’ and the arcane legal/financial spaces of offshore – which in combination constitute an emergent xenotopia. The ‘philosopher’s island’ (Mackay, 2010), therefore, represents a complex and polyvalent spatial form that serves to continuously and expediently redefine the nature of social space.  相似文献   

11.
Through the lens of the dancing body, this paper examines practices of health and wellbeing produced in response to City of Vancouver urban governance policies. In particular, it calls attention to the legislative onslaught by city government in the years abutting the 2010 Winter Olympics to cultivate and manage healthy people, communities, and environments. In an effort to sell Vancouver’s ‘liveability’, I argue City of Vancouver endorsed a new legislative alliance that merged a conspicuously Anglo-American wellbeing lexicon, favouring individual responsibility and self-governance, with the performing arts industries. Drawing upon interviews and performance-based research, the paper illustrates how Karen Jamieson’s community dance project Connect, created for the In the Heart of the City festival, embodies Vancouver’s tri-level legislative ambitions to nurture A Healthy City For All. This materialised through the crafting of a dance-health body practice (healthy people), by choreographing a sense of belonging among ‘at risk’ communities (healthy communities), and in the uniting of the arts and health professions in the process of ‘cleaning up’ disenfranchised neighbourhoods (healthy environments). In bringing together scholarship on cultures of wellbeing and creative dance practice, the article contributes to understandings of how the health-seeking subject is embodied and performed. It also offers a productive critique of the exclusionary nature of urban health legislation, and of the contested role artists and arts festivals can play in nurturing urban wellbeing and normalising inequalities.  相似文献   

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Political memories—which are crucial for establishing and maintaining ‘political capital’, based on individual and group positioning during past conflict and wars, but also in relation to presentday politics—are important when considering varied outcomes from negotiations and other interactions that occur in the Lao People’s Democratic Republic in relation to large-scale economic land concessions. This paper continues to expand on the idea of political memories of past conflicts and wars by considering the concept in relation to the theoretical framework proposed by Hall et al. (2011) in their book Powers of Exclusion, which stresses the importance of interactions between regulation, force, the market and legitimation for understanding different types of exclusionary processes, especially those linked to land access. I argue that political memories are particularly relevant when it comes to legitimation, but that expanding the concept so as to include political memories is important. In relation to large-scale plantation, mining and hydropower dam concessions, I also stress the importance of political memories in (re)shaping understandings of landscapes, thus creating particular varieties of memory laden political landscapes, which too are constituted by the past but are also politically mobilized in the present.  相似文献   

15.
Two branches of silica rockevolution related to oceans and continental blocks have been outlined. The boundaries of changes in types of silica rocks, their formation, and development of the organic world were established: (i) the beginning of the Phanerozoic was related to transformation from microbial to biogenic silica deposition (or to a change in the influence of microbial activity on silica accumulation); (ii) cessation of the formation of cherts enriched in organic matter, which was synchronized with land colonization by organisms in the Devonian, and (iii) an explosive style of global silica accumulation related to the appearance and development of diatoms, which correlates with appearance of angiosperm plants in tropical forests.  相似文献   

16.
This paper draws upon Michael Watts’s work on governable spaces and “economies of violence” in the Niger Delta (2004a,b,c) and Colin Filer’s concept of the “ideology of landownership” in Papua New Guinea (1997) to explore how resource capitalism has been at the heart of violent conflict in post-colonial Melanesia. This schema of the political ecology of violence is elucidated with reference to three governable spaces – landownership, indigeneity, and nationalism; four different resource–industrial complexes – mining, oil and gas, logging, and oil palm; and the region’s three most serious conflicts to date – the Bougainville conflict, the Solomon Islands ‘ethnic tension’, and on-going violence in the Highlands of Papua New Guinea, particularly in Enga and Southern Highlands provinces. It is argued that in each of these places the story of violent conflict is ineluctably one of resource capitalism and its engagement with local socio-political contexts. In sharp contrast to the resource determinism, state-centrism and ahistoricism of much of the ‘resource conflict’ literature, attention to governmentality and scale highlights the highly contextual and contingent nature of resource-related violence in Melanesia. The diverse experiences of different regulatory approaches to the encounters between resource complexes and governable spaces across time and space are also examined, giving rise to policy implications for governing resource conflict in Melanesia.  相似文献   

17.
Abstract

Metamorphism of the Askore Amphibolite, metabasaltic and metasedimentary medium-grade hornblendebearing schists at the northernmost portion of the Ladakh Terrane and of the Shyok Suture Zone, mainly a low-grade volcano-sedimentary series, has been studied in the area between the Chogo Lungma glacier and the Indus river halfway between Skardu and Rondu.

In the Askore Amphibolite the peak assemblage in the amphibolite facies defines the regional metamorphic foliation, and is overprinted by a later static recrystallization at comparable P-T conditions. In spite of similar peak temperatures (630–650°C), geobarometry based on amphibole composition reveals a marked difference between garnet – epidote – andesine amphibolites exposed just above the Main Mantle Thrust at the head of Turmik valley, which equilibrated at high pressures (about 10 kbar) in late Miocene (Tortonian), and biotite – epidote – oligoclase amphibolites outcropping at the mouth of Turmik valley, which equilibrated at pressures of c. 6 kbar before late Eocene (Priabonian).

The Dasu Ultramafite and other smaller lens-shaped bodies of low- to medium-grade metaperidotite separate the Ladakh Terrane from the Shyok Suture Zone. They are antigorite serpentinites, often with talc and magnesite, in which relict cumulitic structures are locally recognisable. The ultramafites may represent remnants of oceanic lithosphere separating the Ladakh-Kohistan island arc from the Asian plate, or they may be deep crustal rocks stripped from the basement of the arc.

The mostly greenschist-facies Shyok Suture Zone shows the lithology of a calc-alkaline volcano-sedimentary series. It is supposed to be a remnant of a back arc basin of early Cretaceous age, separating the arc from the southern margin of Asia. Chloritoid, kyanite and biotite have been found in individual thrust sheets occurring at different structural levels and totally subordinate in volume to very low- and low-grade rocks. Such sharp differences in mineral paragenesis, together with field evidence of local shear, suggest a complex internal structure for the Shyok Suture Zone. From the head of Chogo Lungma glacier to the Basha valley, close to the contact with the Karakorum Metamorphic Complex, the rocks of the Shyok Suture Zone record a late Miocene metamorphic event at medium pressures and temperatures. Thermobarometric and geochronological evidence suggests that this event can be related to the exhumation and thrusting of the Karakorum metamorphic core over the Shyok Suture Zone.  相似文献   

18.
Numerical celestial-mechanical models are used to compare (andg interpolate and forecast) near-diurnal tidal variations in the Earth’s axial rotation and oscillations in the global angular momentum of the atmosphere using the IERS data and NCEP/NCAR meteorological data. In order to improve the accuracy of interpolations and forecasts made for short and intraday time intervals, it is expedient to include the effect of small perturbations in short-term zonal tides, which influence fluctuations in Universal Time UT1 directly related to the Earth’s rotation. Due to the quasi-static formulation of the problem, it is assumed that the dynamics of the thin surface atmosphere are completely determined by the gradient of the tide-generating geopotential, which supports forced oscillations of the entire subsystem (i.e., of the mantle and atmospheric envelope). A comparison of the numerical simulations with the NCEP/NCAR data shows that the model is effective for applications in forecasting atmospheric tides.  相似文献   

19.
This article examines young Peruvians’ aspirations and the role of migration in their imagined futures, from a generational perspective. The data come from Young Lives, a long-term study of childhood poverty combining survey and qualitative approaches with children and their parents. The paper uses a biographical approach that sees migration as part of individual biographies as well as social structures and life course processes. The aim is to deepen understanding of the social contexts in which aspirations for and by children are generated, paying close attention to family migration histories, dynamic household contexts, and children’s migration networks. The analysis focuses on the time-spaces of migration aspirations, showing the way past, present and future are interconnected. It also emplaces aspirations by focusing on the way aspirations by and for children are constituted in and through particular places. The conclusion reflects on the role of poverty and argues that ‘aspirations’ are about much more than abstract ‘futures’; they orient actions in the present and say a great deal about young people’s current realities and relationships.  相似文献   

20.
Bulk mineral resources of iron ores, copper ores, bauxite, lead ores, zinc ores and potassium salt play a pivotal role on the world’s and China’s economic development. This study analyzed and predicted their resources base and potential, development and utilization and their world’s and China’s supply and demand situation in the future 20 years. The supply and demand of these six bulk mineral products are generally balanced, with a slight surplus, which will guarantee the stability of the international mineral commodity market supply. The six mineral resources(especially iron ores and copper ores) are abundant and have a great potential, and their development and utilization scale will gradually increase. Till the end of 2014, the reserveproduction ratio of iron, copper, bauxite, lead, zinc ores and potassium salt was 95 years, 42 years, 100 years, 17 years, 37 years and 170 years, respectively. Except lead ores, the other five types all have reserve-production ratio exceeding 20 years, indicative of a high resources guarantee degree. If the utilization of recycled metals is counted in, the supply of the world’s six mineral products will exceed the demand in the future twenty years. In 2015–2035, the supply of iron ores, refined copper, primary aluminum, refined lead, zinc and potassium salt will exceed their demand by 0.4–0.7 billion tons(Gt), 5.0–6.0 million tons(Mt), 1.1–8.9 Mt, 1.0–2.0 Mt, 1.2–2.0 Mt and 4.8–5.6 Mt, respectively. It is predicted that there is no problem with the supply side of bulk mineral products such as iron ores, but local or structural shortage may occur because of geopolitics, monopoly control, resources nationalism and trade friction. Affected by China’s compressed industrialized development model, the demand of iron ores(crude steel), potassium salt, refined lead, refined copper, bauxite(primary aluminum) and zinc will gradually reach their peak in advance. The demand peak of iron ores(crude steel) will reach around 2015, 2016 for potassium salt, 2020 for refined lead, 2021 for bauxite(primary aluminum), 2022 for refined copper and 2023 for zinc. China’s demand for iron ores(crude steel), bauxite(primary aluminum) and zinc in the future 20 years will decline among the world’s demand, while that for refined copper, refined lead and potassium salt will slightly increase. The demand for bulk mineral products still remains high. In 2015–2035, China’s accumulative demand for iron ores(crude steel) will be 20.313 Gt(13.429 Gt), 0.304 Gt for refined copper, 2.466 Gt(0.616 Gt) of bauxite(primary aluminum), 0.102 Gt of refined lead, 0.138 Gt of zinc and 0.157 Gt of potassium salt, and they account for the world’s YOY(YOY) accumulative demand of 35.17%, 51.09%, 48.47%, 46.62%, 43.95% and 21.84%, respectively. This proportion is 49.40%, 102.52%, 87.44%, 105.65%, 93.62% and 106.49% of that in 2014, respectively. From the supply side of China’s bulk mineral resources, it is forecasted that the accumulative supply of primary(mine) mineral products in 2015–2035 is 4.046 Gt of iron ores, 0.591 Gt of copper,1.129 Gt of bauxite, 63.661 Mt of(mine) lead, 0.109 Gt of(mine) zinc and 0.128 Gt of potassium salt, which accounts for 8.82%, 13.92%, 26.67%, 47.09%, 33.04% and 15.56% of the world’s predicted YOY production, respectively. With the rapid increase in the smelting capacity of iron and steel and alumina, the rate of capacity utilization for crude steel, refined copper, alumina, primary aluminum and refined lead in 2014 was 72.13%, 83.63%, 74.45%, 70.76% and 72.22%, respectively. During 2000–2014, the rate of capacity utilization for China’s crude steel and refined copper showed a generally fluctuating decrease, which leads to an insufficient supply of primary mineral products. It is forecasted that the supply insufficiency of iron ores in 2015–2035 is 17.44 Gt, 0.245 Gt of copper in copper concentrates, 1.337 Gt of bauxite, 38.44 Mt of lead in lead concentrates and 29.19 Mt of zinc in zinc concentrates. China has gradually raised the utilization of recycled metals, which has mitigated the insufficient supply of primary metal products to some extent. It is forecasted that in 2015–2035 the accumulative utilization amount of steel scrap(iron ores) is 3.27 Gt(5.08 Gt), 70.312 Mt of recycled copper, 0.2 Gt of recycled aluminum, 48 Mt of recycled lead and 7.7 Mt of recycled zinc. The analysis on the supply and demand situation of China’s bulk mineral resources in 2015–2035 suggests that the supply-demand contradiction for these six types of mineral products will decrease, indicative of a generally declining external dependency. If the use of recycled metal amount is counted in, the external dependency of China’s iron, copper, bauxite, lead, zinc and potassium salt will be 79%, 65%, 26%, 8%, 16% and 18% in 2014, respectively. It is predicted that this external dependency will decrease to 62%, 64%, 20%,-0.93%, 16% and 14% in 2020, respectively, showing an overall decreasing trend. We propose the following suggestions correspondingly.(1) The demand peak of China’s crude steel and potassium salt will reach during 2015–2023 in succession. Mining transformation should be planned and deployed in advance to deal with the arrival of this demand peak.(2) The supply-demand contradiction of China’s bulk mineral resources will mitigate in the future 20 years, and the external dependency will decrease accordingly. It is suggested to adjust the mineral resources management policies according to different minerals and regions, and regulate the exploration and development activities.(3) China should further establish and improve the forced mechanism of resolving the smelting overcapacity of steel, refined copper, primary aluminum, lead and zinc to really achieve the goal of "reducing excess production capacity".(4) In accordance with the national strategic deployment of "One Belt One Road", China should encourage the excess capacity of steel, copper, alumina and primary aluminum enterprises to transfer to those countries or areas with abundant resources, high energy matching degree and relatively excellent infrastructure. Based on the national conditions, mining condition and geopolitics of the resources countries, we will gradually build steel, copper, aluminum and lead-zinc smelting bases, and potash processing and production bases, which will promote the excess capacity to transfer to the overseas orderly.(5) It is proposed to strengthen the planning and management of renewable resources recycling and to construct industrial base of renewable metal recycling.(6) China should promote the comprehensive development and utilization of paragenetic and associated mineral species to further improve the comprehensive utilization of bulk mineral resources.  相似文献   

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