Coupled Dynamics and Regime Shifts in Coupled Human-Water Systems and Their Consequences on Migration

Abstract:

Today, population displacement triggered by hydrological extremes has become increasingly common around the world. Social and hydrological dynamics of coupled human-water systems play a role in determining drivers of migration. To clarify and enhance our understanding of such dynamics, we developed a stylized model that combines hydrological and social dynamics of a generic coupled human-water system. In this model, neither too much (flood) nor too little water (drought) is desirable, and the population self-organizes to respond to relative benefits they derive from the water system and outside opportunities. Despite its simplicity, the model yields seven different regimes, governed by hydrological and socioeconomic factors. As these factors change, these regimes shift, and social consequences such as migration patterns shift with them. The results show gradual migration in response to drier conditions and abrupt exodus in response to an increase in flood risk. Clear understanding of such regime boundaries derived from this simple model contributes to insights on how one might cope with a complex socio-hydrological system under change.