UC San Diego

Previous empirical studies have suggested that climate change induces human migration in Mexico by damaging agricultural livelihood and worsening habitability. However, these studies present different opinions on how water availability affects migration. Also, a high-spatial-resolution climate migration analysis that covers a long-time period is lacking. This study employs two water availability data sets and two migration data sets with high spatial resolution and extended temporal coverage. Firstly, I look at two hydroclimate data sets, ground-station-based and satellite-based, to examine the surface water dynamics in Mexico. Secondly, two migration data sets, modeled gridded data and census data, are analyzed to identify the internal and international migration patterns at the municipality-level in Mexico. Lastly, migration rate is regressed on various climate metrics, including temperature trend and variability, precipitation trend and variability, and surface water trend. In addition, climate metrics' impacts on rural-urban migration flow are examined separately. The investigation of two hydroclimate data reveals the limitation to capture surface water dynamics at fine-scale, the municipality-level, in Mexico. Also, the comparison of two migration data sets displays a huge international migration flow in Mexico. Lastly, the regression results suggest a closer climate's relationship with international migration than internal migration. They also show a consistent delay response of migration after environmental stressors.