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

NDVI is calculated as a normalized ratio of measured reflectivity in the red and near
infrared (NIR) portions of the electromagnetic spectrum: NDVI = NIR – Red / NIR + Red
(NASA EO 2008). The NDVI values range from -1.0 to 1.0. Negative values indicate
impervious surfaces (e.g., water, clouds or snow). Values close to zero indicate bare soils or
spare vegetation. NDVI tends to increase with increases in green leaf biomass (density) or
leaf area index; values above 0.2 indicate increasing amounts of green vegetation and can be
used to differentiate categories of green vegetation (e.g., forests, croplands, grasslands)
(Tarpley et al. 1984, Myneni et al. 1995).
Since NOAA satellites have gathered global climate data for more than 25 years,
long-term NDVI data records exist (NASA EO 2008). The difference between the average
NDVI for a particular month of a given year and the average NDVI for the same month over
a period of years is called the NDVI anomaly. The NDVI anomaly can be used to
characterize the health of vegetation and infer the amount of rainfall or ground moisture in a
given area, relative to the norm (Tucker et al. 1985).
In addition to being associated with increasing green biomass and photosynthetic
activity, NDVI is a useful correlate of rainfall and ground moisture changes (Nicholson et al.
1990; Justice et al. 1985; Linthicum et al. 1987, 1990). Because vegetation growth is limited
by water, the relative density of vegetation is a reliable indicator of moisture. There is a near
linear relationship between NDVI and precipitation (Tucker et al. 1985, Nicholson et al.
1990).
Many studies have demonstrated how this relationship can be used to infer ecological
parameters associated with RVF viral activity. These studies have linked vector presence and
population dynamics to precipitation and green vegetation dynamics (Tucker et al. 1985,
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