Environmental Variability, Migration, and Rural Livelihoods

描述(由申请人提供)：关于环境变化和变异性如何影响移民决策，从而影响人口再分配，人们知之甚少。这种理解很重要，因为移徙对个人和社区的健康和福祉具有影响。此外，鉴于政府间气候变化专门委员会最近发布的报告断言气候系统存在“明确的”变化(气专委2007：4)，并预期未来区域降水和温度模式将继续变化，因此加强对移徙的环境因素的理解是至关重要的。这些变化中的许多将对本已脆弱的地区造成最严重的影响，包括我们的研究背景--南非农村，那里的降水和温度预计会发生变化。在这些农村地区，生计往往以严重依赖当地自然资源为特点。重要的陆上活动包括可耕种农业、畜牧业以及自然资源(如薪材、野生药草)的消费和贸易。自然资源也是应对失业和/或死亡等家庭冲击的“缓冲器”。鉴于对资源的高度依赖，当地植被覆盖的变化(由于降水/温度模式的变化)具有巨大的影响生计的潜力。与迁出有关，生计选择的减少可以作为形成移徙趋势的“推动”因素。利用“农村生计”框架，我们在一个卫生和人口监测点--阿金库尔卫生和人口股(AHPU)内，模拟了外流人口(2002年和2007年)与当地自然资源的可获得性和可变性(2002-2006年)之间的关系。AHPU位于南非东北部的一个贫困农村地区，自1992年以来，每隔12-18个月收集一次人口普查数据，从21个村庄的12,000多户家庭中收集数据。此外，它位于陡峭的局部拓扑梯度内，使得整个研究环境中的植被可用性有很大差异。我们结合了社会经济和遥感数据来衡量当地的“绿色度”，并开发了多变量的空间信息模型来检查外流以及邻近自然资源的可用性和可变性。除了具体的研究成果外，该项目还被设计为开发纵向模型的基础，该模型利用人口监测环境提供的人口-环境分析能力。事实上，很少有现有的适当数据来模拟社会经济和环境过程之间的关联，而健康和人口监测地点代表着处理这些复杂关联的独特机会。 公共卫生相关性：这项研究将提高对农村生计，特别是与移民决策有关的农村生计与欠发达国家贫困农村地区环境变化之间的联系的理解。由于高度依赖当地的自然资源，如薪材和野生食物，这些地区的居民特别容易受到环境变化的影响。移徙可以作为应对当地自然资源可获得性变化的一种应对战略，尽管搬迁对移徙者以及接受地的个人和社区的健康和福祉具有重要影响。

DESCRIPTION (provided by applicant): Little is known about the ways in which environmental change and variability shape migration decision-making and, therefore, population redistribution. Such understanding is important because migration has implications for the health and well-being of individuals and communities. In addition, an improved understanding of migration's environmental dimensions is essential given the recently-released report by the Intergovernmental Panel on Climate Change which asserts there are "unequivocal" changes in the climate system (IPCC 2007:4) with future expectations of continued shifts in regional precipitation and temperature patterns. Many of these changes will most severely impact already-vulnerable regions including rural South Africa, our study setting, where precipitation and temperature shifts are anticipated. In these rural settings, livelihoods are often characterized by heavy dependence on local natural resources. Important land-based activities include arable farming, livestock husbandry, and consumption and trade in natural resources (e.g., fuelwood, wild herbs). Natural resources also act as "buffers" against household shocks such as job loss and/or mortality. Given this high level of resource dependence, changes in local vegetation cover (due to shifts in precipitation/temperature patterns) hold tremendous potential to impact livelihoods. As related to outmigration, a decline in livelihood options can act as a "push" factor shaping migration trends. Using a "Rural Livelihoods" framework, we model the association between outmigration (in 2002 and 2007) and the availability and variability of local natural resources (2002-2006) within a health and demographic surveillance site, the Agincourt Health and Population Unit (AHPU). Located in an impoverished rural area in the South Africa's northeast, the AHPU has collected census data at 12-18 month intervals since 1992 from over 12,000 households in 21 villages. In addition, its location within a steep local topological gradient affords substantial variation in vegetation availability across the study setting. We combine socioeconomic and remotely sensed data measuring local "greenness," and develop multivariate spatially-informed models to examine outmigration and the availability and variability of proximate natural resources. In addition to specific research results, this project is designed as a foundation for development of longitudinal models tapping into the analytical strength for population-environment provided by demographic surveillance settings. Indeed, there are few settings with existing, appropriate data for modeling the associations between socioeconomic and environmental processes and health and demographic surveillance sites represent unique opportunities to grapple with these complex associations. PUBLIC HEALTH RELEVANCE: This research will improve understanding of the association between rural livelihoods, especially related to migration decisions, and environmental change in impoverished rural areas of less developed countries. Residents of these regions are especially vulnerable to environmental changes due to high reliance on local natural resources such as fuelwood and wild foods. Migration can be a coping strategy in response to changes in the availability of local natural resources, although relocation has important consequences for health and well-being of migrants and of individuals and communities in receiving areas.