Sea level rise (SLR) could have catastrophic consequences worldwide. More than 600 million people currently living in coastal areas may see their livelihood at risk and choose to migrate in the near future. Predicting when, how, and where people could migrate under environmental change is critical to devise effective policy initiatives and improve our preparedness. Here, we propose a modeling framework to predict the effect of SLR on migration patterns from easily accessible geographic and demographic data. The framework adapts the radiation model to capture unwillingness or inability to migrate of affected residents, as well as return migration and cascading effects in migration patterns. We apply the mathematical model to study internal migration in Bangladesh, where we predict a complex and counterintuitive landscape of migration patterns between districts. Our predictions indicate that the impact of SLR on 816,000 people by 2050 will trigger cascading effects in migration patterns throughout the entire country. The population of each of the 64 districts will change, leading to a total variation of 1.3 million people. Migration from inundated regions in the center will trigger non‐trivial patterns, including a reduction in the population of the district of the capital Dhaka.

中文翻译：

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环境变化下的人类迁徙建模：孟加拉国海平面上升的影响的案例研究

海平面上升（SLR）可能在全球范围内造成灾难性后果。目前居住在沿海地区的超过6亿人口可能面临生计危机，并选择在不久的将来移民。预测在环境变化下人们何时，如何以及在何处迁移对于设计有效的政策计划和改善我们的准备至关重要。在这里，我们提出了一个建模框架，用于根据易于访问的地理和人口统计数据预测SLR对迁移模式的影响。该框架调整了辐射模型，以捕获不愿或无法迁移受影响居民的情况，以及返回迁移和迁移模式中的级联效应。我们运用数学模型研究孟加拉国的内部移民，在这里，我们可以预测区域之间迁移模式的复杂且违反直觉的情况。我们的预测表明，到2050年，SLR对816,000人的影响将触发整个国家迁移模式的连锁效应。64个地区中每个地区的人口都将发生变化，从而导致130万人的总变化。从中心的受灾地区迁移将触发非平凡的模式，包括首都达卡地区人口的减少。