Sample A: Cover Page of Thesis, Project, or Dissertation Proposal

3.5 EVALUATION OF MOSQUITO DENSITY – ENVIRONMENTAL-CLIMATIC RELATIONSHIPS
The Normalized Difference Vegetation Index (NDVI) is a proven biologically
realistic index of environmental factors influencing mosquito populations. Animal life
depends on vegetation, so tracking spatial-temporal variation in vegetation similarly
evaluates animal populations (Hielkema et al. 1986). The goal in these regional analyses was
to evaluate the relationship or association between NDVI and Virginia mosquito density.
Since a species is sampled at multiple locations and NDVI raw and anomaly values vary
among locations, mosquito density-NDVI relationships were examined spatially within the
2005-2006 time period for each region as well as temporally by region on a monthly time
scale. In the analysis of these relationships, the null expectation or hypothesis is that the
mosquito density-NDVI relationships across space and across time are the same, and forms
the basis for using NDVI to develop a predictive model for un-sampled areas in Virginia.
Temperature and precipitation (in addition to NDVI) have previously been reported
to affect mosquito biology (Alto and Juliano 2001, Turell et al. 2005). Environmental-
climatic variables (temperature, precipitation, and NDVI) were evaluated to determine which
variable is a better predictor of mosquito distribution and abundance.
Data preparation
Data was not available for all counties for 2000-2006. The majority of the reliable
data was for 2005-2006 for the Northern Virginia, Richmond-Petersburg, and Hampton
Roads regions. Therefore, only mosquito surveillance data and predictor data (NDVI,
elevation, temperature, precipitation, and temperature-rainfall derived values) for 2005-2006
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