TITLE:

EMERGENCE IN COUPLED HUMAN-LANDSCAPE INTERACTIONS: COMBINED NUMERICAL AND AGENT-BASED MODELS FOR BARRIER ISLAND RESORTS AND FLOOD DISASTER AND RESPONSE IN NEW ORLEANS (No. 142)

DATE:

Friday, February 2nd, 2007

TIME:

3:30 PM

LOCATION:

GMCS 214

SPEAKER:

Dylan McNamara, Complex Systems Laboratory, Scripps Institution of Oceanography

ABSTRACT:

As humans increasingly occupy, modify and interact with marginal landscapes, forecasting the resulting previously unobserved long-time- scale, emergent behaviors is possible only using numerical models, not experience. Using novel combined numerical landscape models and agent-based models for economic development and hazard mitigation we explore emergent behaviors of barrier island resorts and flood disaster and response in New Orleans.
In the model for barrier island resorts including coastal erosion and accretion, island overwash, alongshore sediment transport, dunes, hotel and tourism markets, storm damage, and beach and dune replenishment based on weighing costs against projected effect on tax revenue, barrier island response to rising sea level is destabilized, 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. Results suggest that coastal areas that have recently instituted protection measures eventually will experience a widespread upsurge in damage if these measures are sustained, even in the absence of climate-change-induced increased storminess.
The numerical model for New Orleans including Mississippi River floods, storm-surge-induced floods, subsidence, port services, tourism, home and labor markets, flood damage and levee or spillway construction based on weighing costs against damage from the last flood qualitatively reproduces the geographical expansion of New Orleans and increases in river and lake levee elevations. High frequency, small-to-intermediate-flood events are prevented at the expense of experiencing infrequent, large floods. Inclusion of discounted future damage costs in market transactions limits economic exploitation of New Orleans but substantially decreases damage. Using the model to project forward in time suggests that Hurricane Katrina likely will not be the last disaster to strike New Orleans if short- time-scale economic calculations drive protection decisions.

HOST:

Jose Castillo

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