Coupled barrier island-resort model: 1. Emergent instabilities induced by strong human-landscape interactions

Abstract

As humans increasingly occupy and modify marginal landscapes, previously unobserved long timescale, emergent behaviors related to interactions between natural processes and human agency are possible. Barrier islands, which are low-lying strips of sand separated from a coast by lagoons, cut by inlets and topped by sand dunes, have been significantly modified through the development of tourist resorts. Resorts and barrier islands are dynamically coupled through storm damage and beach erosion, and measures taken to prevent or mitigate them. In response to rising sea level, a natural barrier island migrates steadily up the continental shelf. In contrast, we show that in a novel numerical model-coupting barrier island processes with resort development, storm damage, and hazard mitigation, policy decisions driven by market dynamics destabilize barrier island response to rising sea level, giving rise to emergent, episodic boom and bust cycles, which alternate in phase alongshore, and less frequent, regionally extensive resort destruction events. Developed barrier islands are precariously maintained at lower elevations and further offshore than their natural counterparts, a situation exacerbated by insurance, which can lead to island inundation. Our results suggest that coastal areas that have recently instituted protection measures eventually will experience a widespread upsurge in damage if these practices are sustained, even in the absence of climate-change-induced increased storminess. Copyright 2008 by the American Geophysical Union.