生活方式型移民研究综述

在经济比较发达以及后现代社会带来个人主体性增强的背景下,以寻找更好的生活方式的迁移——“生活方式型移民”成为一种重要的人口流动类型,并受到西方学者的高度关注。在中国,生活方式型移民开始萌芽,然而研究较少,目前主要集中在对生活方式型旅游企业主移民研究;西方的研究则涉及退休移民、生活方式型企业主移民等多种类型,但尚未形成完整的研究体系,对于生活方式型移民概念界定及其类型划分较为杂乱。为此,本文从现有文献出发,试图对这类移民的研究内容进行介绍、探讨、厘清和评析,首先确定“生活方式型移民”的概念框架,根据生产和消费在时间和空间上的结合状态将生活方式型移民划分为三种类型,并从社会交往、生活状态、旅游行为和自我认知等方面综述其迁移后的行为表现及由此产生的影响,希望借此促进中国学者对生活方式型移民的关注。     

Internal migration in Peru

"E. G. Ravenstein proposed 'laws of migration' to explain the movement of population in the British Isles from data in the 1881 census. Here, migration in Peru is studied using data from the 1981 census to ascertain the extent to which Ravenstein's 'laws' hold for a different country at a different time.... In conclusion, it is a salutory exercise to apply Ravenstein's seven laws and other findings to Peru and to see how, in a different environment a good time ago, someone could produce a model with wide applicability."     

Questions of migration and belonging: understandings of migration under neoliberalism in Ecuador

This paper explores alternative understandings and experiences of migration under neoliberalism in Ecuador. Through the case study, the study examines migrants' multiple motivations for mobility and their ambivalence toward the process. Insights from the transnational migration literature were drawn in order to think through the implications of an increasingly contradictory context of economic modernization and its impact upon the sense of possibilities and belonging of migrants. In-depth interviews with urban-destined migrants in Ecuador were drawn to argue that mobility produces ambivalent development subjects. This argument is developed in three sections. First, the paper centers on the epistemological and theoretical basis for the relevance of migrant narratives in extending theorizations of migration. Second, in-depth interviews with migrants to Quito are drawn to explore migrants' sense of belonging and regional affiliation, identity formation through migration, and experiences of alienation and disruption in their lives. Lastly, this paper concludes with a retheorization of the role of migration places in the migrant identity construction.     

International retirement migration in Europe

"This paper presents a review and prospectus of international retirement migration (IRM), dealing mainly with European evidence but also referring to some analogous trends in North America. The paper is in three main parts. It first makes the case for regarding IRM as a significant aspect of population geography and of migration studies; in certain areas of Mediterranean Europe, IRM also has effects on regional economic geography. The second section of the paper discusses some of the early findings from a comparative study of British elderly residents in Tuscany, Malta, the Costa del Sol and the Algarve.... The final part of the article offers further reflections on why IRM is important--for the individual migrants themselves, for the host communities, and for public policy."     

当代国际移民创业研究进展

移民创业活动是经济地理学研究中一个重要主题。创业是一种经济活动,但不同群体的创业活动蕴含着不同文化内涵和行为选择。移民创业的研究是解读移民群体社会与文化形成的一个关键的维度。移民群体具有明显的边界,其内部的空间秩序、社会网络、族裔文化以及共同的身份认同都是值得探讨话题,因此学界对移民创业活动给予了持续的关注。移民活动日益频繁,所涉及的行业地域日益扩大,对移民创业群体的研究有利于促进区域经济发展、了解全球政治网络,沟通地理学与社会学和经济学的研究融合,是经济地理学研究中值得关注的问题。本文基于Citespace软件,运用文献分析法,从国际移民创业概念内涵阐述、研究动态、研究前沿及演变、未来研究可能四个方面出发,阐述移民创业研究的历史脉络及进展。研究发现美国和英国在移民创业中占有重要地位。区域创业环境是研究者们主要关注的话题,与创业联系最为紧密的是绩效（0.28）、自雇佣（0.17）和组织（0.17）等关键词研究。全球化趋势不可逆转,跨国主义日趋强盛,未来关于移民及移民创业的研究大有可期。     

Wave train model for knickpoint migration

Rivers respond to a drop in their base level by incising the topography. The upstream propagation of an incision, as usually depicted by a knickpoint migration, is thought to depend on several parameters such as the drainage area, lithology, and the amplitude of the base level drop. We first investigate the case of the Messinian Salinity Crisis that was characterized by the extreme base level fall (1500 m) of the Mediterranean Sea at the end of the Miocene. The response of drainage areas of three orders of magnitude (10³ to 10⁶ km²) highlights the dominant role of the drainage area (with a square root relationship) in controlling the knickpoint migration after a base level fall. A compilation of mean rates of knickpoint propagation for time durations ranging from 10² to 10⁷ years displays a similar relationship indicating that successive wave trains of knickpoint can migrate in a river: first, wave trains linked to the release of the alluvial cover and then, wave trains related to the bedrock incision, which correspond to the real time response of rivers. Wave trains with very low retreat rates (long lived knickpoints > 1 My) rather correspond to the response time of regional landscape.     

Elongation and migration of sand dunes

Two distinct processes are known to act on dynamic dunes, the process of migration by erosion on the windward side and deposition on the lee side, typical for transverse dunes, and the process of elongation typical for linear dunes. These two processes are determined by wind direction relative to the dune alignment. This article reviews the assertion that linear dunes experience lateral displacement in addition to elongation. Fieldwork on vegetated linear dunes (VLDs) and GIS work on seif dunes indicates no lateral migration for these dunes. Linear dunes can shift laterally only when a slip face, formed on the lee side, reaches the plinth of the dune. The winds from both sides of the seif dune are never symmetric; usually winds from one direction are more dominant and effective. The outcome is the formation of peaks and saddles along the dune. The strongest winds create a slip face on the lee side of the peak segments of the dune, oblique to the dune alignment, which reaches the base of the dune and displaces the peak downwind along the dune alignment. The internal structure of the seif dune is formed mostly by this dominant wind direction and gives the impression that the dune has shifted laterally. On the other hand, there are cases in which the wind directions relative to dune alignment fall between those of transverse and seif dunes. In such cases, both processes act on the dune, which subsequently experiences migration as well as elongation.     

Hazards and 'forced' migration in Bangladesh

This paper deals with two basic assumptions about migration patterns in Bangladesh. First, it is commonly assumed that poverty and landlessness in rural Bangladesh lead to migration to and settlement in disaster-prone areas along the main rivers or in low-lying areas in the Bay of Bengal. Second, it is also commonly assumed that when people living in these areas experience loss of land, property and income opportunities due to natural disasters, they are forced to seek their livelihood and housing in urban areas. These two assumptions are discussed on the basis of data from a char in Jamuna river and a slum settlement in Dhaka.     

Split-step complex Padé-Fourier depth migration

We present a split-step complex Padé-Fourier migration method based on the one-way wave equation. The downward-continuation operator is split into two downward-continuation operators: one operator is a phase-shift operator and the other operator is a finite-difference operator. A complex treatment of the propagation operator is applied to mitigate inaccuracies and instabilities due to evanescent waves. It produces high-quality images of complex structures with fewer numerical artefacts than those obtained using a real approximation of a square-root operator in the one-way wave equation. Tests on zero-offset data from the SEG/EAGE salt data show that the method improves the image quality at the cost of an additional 10 per cent computational time compared to the conventional Fourier finite-difference method.     

The geography of highly skilled international migration

"The present paper provides a research review of recent literature on international migration by the highly skilled. Its principal aim is to identify the themes which are being discussed, and suggest where research into the subject might best proceed.... [The authors outline] the two most important perspectives in extant research, economic and socio-cultural, [and review] what is known about the geography of migration by the highly skilled.... The paper proposes...a reconceptualisation of migration by the highly skilled as one element in the international movement of expertise."     

The geography of Bangladeshi migration to Rome

"With reference to the Bangladeshi community in Rome, this paper provides some answers to three key geographical questions: what is the migrants' regional pattern of origin in their home country; what are the mechanisms and routes of their migration to Italy; how are they spatially distributed in Rome?... Chain migration links specific origins in Bangladesh with spatial clusters and economic activities in Rome; the key here is the role of Bangladeshi community leaders in Rome who act both as migration sponsors and entrepreneurs."     

当代国际人口迁移的新形势

战后以来,国际人口迁移规模显著扩大,由发展中国家流向发达国家成为当代国际人口迁移的主流,1950～2000年间,由前者流向后者的净移民共达5800余万人,占同期内后者人口总增量的16%,但占前者自然增量的比重则不足2%。相对于本国自然增长,受移民迁入影响较大的有两类国家：（1）以往人口较少者,如西亚诸石油输出国;（2）自然增长率极低者,如西欧诸国。