Tuesday, August 4, 2009
Exhibit Hall NE & SE, Albuquerque Convention Center
Zainab R. Naqvi, Department of Environmental Science, Baylor University, Waco, TX and Sara E. Alexander, Anthropology, Forensic Science and Archaeology, Baylor University, Waco, TX
Background/Question/Methods The El Niño Southern Oscillation (ENSO) occurs in an irregular cycle of every 2-7 years and influences Central America through decreased rainfall during El Niño years and increased rainfall during La Niña years. In this study, we show that environmental changes associated with hurricane impacts are geographically-associated with vector-borne disease incidence in Belize, Central America, specifically malaria and dengue fever. To assess mesoclimatic influence on hurricane frequency, ENSO events, measured by monthly Southern Oscillation Index (SOI) values, were found to be correlated to hurricanes that impacted Belize specifically based on records from 1985 to 2007. Hurricane impacts were analyzed by utilizing satellite data from the Advanced Very High Resolution Radiometer (AVHRR) prior to and following hurricane events.
Results/Conclusions
Results indicate that hurricane activity increased during La Niña type years, years which exhibit positive SOI values, causing higher levels of precipitation and higher temperatures in Belize. AVHRR data showed land cover change represented by canopy cover loss. Hurricane canopy impacts were geographically diverse across Belize for each hurricane, and canopy recovery occurred within a year, as measured by vegetation indices. Saturated soils were also detected from the AVHRR data following hurricanes with surface ponding persisting as long as one month following storms. These ponds were considered conducive to mosquito breeding and development. Surface temperatures inferred from the AVHRR data showed that post-hurricane temperatures were briefly lower, and then increased over time, indicating ponds that remained following hurricane rains that dried up. Incidence rates of malaria and dengue analyzed in relation to satellite-predicted inland flooding locations show some correlation. Urbanization by geographic distance tended to reduce infection rates as a result of preventative measures such as pesticide application or draining of ponded areas. This project was part of a larger study to analyze human population vulnerability and resiliency in Belize in relation to short and long-term climate fluctuations.
