Leyk Stefan, Maclaurin Galen J, Hunter Lori M, Nawrotzki Raphael, Twine Wayne, Collinson Mark, Erasmus Barend
Department of Geography, University of Colorado Boulder, Boulder, CO, USA.
Appl Geogr. 2012 May;34:559-568. doi: 10.1016/j.apgeog.2012.02.009. Epub 2012 Mar 28.
Migration-environment models tend to be aspatial within chosen study regions, although associations between temporary outmigration and environmental explanatory variables likely vary across the study space. This research extends current approaches by developing migration models considering spatial non-stationarity and temporal variation - through examination of the migration-environment association at nested geographic scales (i.e. whole-population, village, and subvillage) within a specific study site. Demographic survey data from rural South Africa, combined with indicators of natural resource availability from satellite imagery, are employed in a nested modeling approach that brings out distinct patterns of spatial variation in model associations derived at finer geographic scales. Given recent heightened public and policy concern with the human migratory implications of climate change, we argue that consideration of spatial variability adds important nuance to scientific understanding of the migration-environment association.
迁移-环境模型在选定的研究区域内往往不考虑空间因素,尽管临时外出迁移与环境解释变量之间的关联可能在整个研究空间中有所不同。本研究通过开发考虑空间非平稳性和时间变化的迁移模型来扩展当前方法——通过在特定研究地点内的嵌套地理尺度(即总体、村庄和村庄以下区域)研究迁移-环境关联。来自南非农村的人口调查数据,结合卫星图像中的自然资源可用性指标,被用于一种嵌套建模方法,该方法揭示了在更精细地理尺度上得出的模型关联中不同的空间变化模式。鉴于近期公众和政策对气候变化对人类迁移影响的关注度提高,我们认为考虑空间变异性为科学理解迁移-环境关联增添了重要的细微差别。