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81.
82.
Climate change,environmental degradation and migration 总被引:1,自引:0,他引:1
Climate change will have a progressively increasing impact on environmental degradation and environmentally dependent socio-economic
systems with potential to cause substantial population displacement. The key concerns in Less Developed Countries (LDCs) will
include serious threats to food security and health, considerable economic decline, inundation of coastal areas, and degradation
of land and fresh water resources (Reuveny in Polit Geogr, 2007). The relationship between environmental change and potential humanitarian crises has been captured by: McGregor (Geography
and refugees: patterns and processes of change, Belhaven Press, London, pp 159–70, 1993), Kibreab (Environment and Population Change, International Union for the Scientific Study of Population, Liège, 1994), Kibreab (Disasters 21(1):20–38, 1997), Myers (Bioscience 43:752–761, 1993), Myers and Kent (Environmental exodus: an emergent crisis in the global arena, Climate Institute, Washington, DC, 1995), Black (New Issues in Refugee Research, Working Paper no. 34, 2001), Lee (Environmental matters: conflict, refugees and international relations, World Human Development Institute Press, Seoul
and Tokyo, 2001), Castles (Environmental Change and Induced Migration: Making Sense of the Debate Working Paper No. 70, 2002), Christian Aid (Human tide: the real migration crisis, Christian Aid, London, 2007), and Massey et al. (, 2007). However, we know little about the interplay between environmental change and stresses on ecological systems, resulting
socio-economic vulnerability and potential outcomes in terms of population displacement or induced migration. So far these
relationships are poorly conceptualized, lack systematic investigation, and are reduced to simplistic causal explanations.
This leads to misleading conclusions that deny the complex multivariate processes—environmental, political, social, and economic—
which are the root causes of environmentally induced migration and/or conflict. When people are faced with severe environmental
degradation they have one of three options: (1) stay and adapt to mitigate the effects; (2) stay, do nothing and accept a
lower quality of life; or (3) leave the affected area. The process of movement and migration is usually subject to a complex
set of push and pull forces, where push forces relate to the source area while pull factors relate to the destination. These
forces are in constant flux, as much as environmental change, and interact with socio-economic and political conditions including
state or government decision making powers, which can tip the balance at any point by either denying movement or the right
to settle elsewhere. The paper focuses on how environmental change and environmental hazards contribute to the migration by
exploring the mechanisms through which vulnerability and migration are linked—via livelihoods, relocation policies, and other
factors. The paper begins by outlining important definitions of what is environmentally induced migration. The paper also
considers the question of whether migration is a process that reduces or increases vulnerability. The paper draws on multidisciplinary
literature including ecology, environment, and climate change; sociology of migration; anthropology of displacement; and economics;
but also on preliminary from various case studies in Egypt, Vietnam, and Mozambique. 相似文献
83.
Abstract In the long term, the Kyoto Protocol will be insufficient to stabilize the greenhouse gas (GHG) concentrations in the atmosphere; quantified commitments will also be essential for major developing countries (and the US). International cooperation mechanisms, such as permit trading systems, can help achieve global economic efficiency. However, the initial allocation of emission permits raises many debates on equity. The main objective is to propose a decision aid tool for decision makers, which is capable of providing relevant information on various equitable permit allocation schemes and burden sharing. A dynamic multicriteria model is proposed to share the global quantity of permits among 15 regions, taking into account multiple definitions of equity and regional interests. The World-MARKAL energy model is used to compute the gross reduction cost (before permit exchanges) for each region. Afterward, it is possible to calculate their net reduction costs (after permit exchanges) according to different allocation schemes. A realistic simulation of the tool provides examples of results, i.e. ranges of permit allocations and net costs for each region. Finally, some recommendations are proposed to policy makers to design a decision process adapted to the global context of negotiations. 相似文献
84.
85.
The riparian zone is in intimate contact with the river and, as such, is a critical zone for understanding hydrological problems. This paper presents a general modelling methodology for the assessment of riparian hydrological processes. It is applicable to a wide range of riparian spaces and incorporates current expertise in numerical methods. A core part of the modelling methodology is the random walk particle method (RWPM). We develop an RWPM as part of the ESTEL2D subsurface flow model, test it against analytical solutions and apply it to the simulation of parcels of water as they move through the riparian zone. The modelling methodology provides a new opportunity to assess fundamental hydrological process issues such as the proportioning of pre‐event and event water storm runoff, and reversals of flow in floodplains. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
86.
Cold Dust and Very Cold Excess Emission in the Galaxy 总被引:2,自引:0,他引:2
Hervé Bourdin Françcois Boulanger Jean-Philippe Bernard Guilaine Lagache 《Astrophysics and Space Science》2002,281(1-2):243-246
We provide insight in the origin of the far-IR to mm emission from galaxies by presenting a decomposition of the Galaxy emission
where we separate the contributions from dust in the atomic gas and dust associated with quiescent molecular gas as a function
of Galacto-centric distance. This decomposition leaves a puzzling very cold emission excess with a brightness independent of Galactic longitude that might be pointing at interstellar matter in the
outer Galaxy not traced by H I nor CO emission.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
87.
88.
Yunzhao Wu Sebastien Besse Jian-Yang Li Jean-Philippe Combe Zhenchao Wang Xianfeng Zhou Chao Wang 《Icarus》2013,222(1):283-295
The main objective of this study is to develop a new photometric correction that is suitable for global Chang’ E-1 (CE-1) Interference Imaging Spectrometer (IIM) data. We considered two improvements in the accuracy of the photometric correction: (1) classifying the whole Moon’s surface into four classes (very bright rays, mature highlands, low FeO basalts, and high FeO basalts) based on the FeO contents; (2) decoupling the combined effects of the solar photometry and the detector responsivity along the cross-track. The results showed that our decoupling method could correct the non-uniformity of detector response but retain the cross-track photometry. Based on these in-flight calibrated data, spectrally continuous photometric functions of the four classes were obtained. By eliminating the contamination from highlands ejecta and low FeO basalts, the opposition surge of the high FeO maria was evident for the first time. The amplitude and width of the opposition surge presents wavelength dependence, which suggests that shadow hiding is the mechanism responsible for the opposition surge. A global lunar reflectance map whose boundaries between adjacent orbits are invisible was generated using the new four-type photometric functions. The quality of the global mosaic and the consistency of the reflectance spectra of the same area obtained in different orbits indicate the effectiveness of our photometric correction method. Although our method was specifically applied to the IIM data, the photometric correction method and the parameter values derived in this study is expected to be suitable for other optical instruments. 相似文献
89.
90.
Anja M. Scheffers Sander R. Scheffers Dieter H. Kelletat Peter Squire Lindsay Collins Yuexing Feng Jian‐Xin Zhao Renaud Joannes‐Boyau Simon Matthias May Gerhard Schellmann Heather Freeman 《第四纪科学杂志》2012,27(7):713-724
Prehistoric storm records are relatively scarce in most parts of the world. This article presents storm records derived from coral rubble‐based geological archives of the Houtman Abrolhos Archipelago located off the west coast of Australia, where the southernmost coral reefs of the Indian Ocean are found. Winter storm swell from the circum‐Antarctic ‘Brave Westerlies’, as well as tropical cyclone waves, have left numerous ridge systems on dozens of islands of the archipelago, all composed of coral rubble from adjacent reefs. At three islands, seven ridge systems were dated by three different methods: U‐series (68 dates), radiocarbon (64 dates), electron spin resonance (7 dates); 139 radiometric dates span the last 5500 years of the Holocene. In contrast to the geomorphological interpretation, the age sequences show ‘inversions’, hiatuses and different ages for the same ridge, all pointing to complicated ridge formation processes. Time gaps, some exceeding 1000 years, are interpreted as phases of erosion and not as phases without storm activity. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献