GMI
expert NEXRAD analysts use NEXRAD data to assist wind and airport
developers with pre- and post-construction risk assessments for
birds, especially migratory birds. GMI provides an analysis of
NEXRAD data in order to characterize the bird migration temporal
pattern at a proposed wind or airport site. GMI analyzes the
previous three to five years of NEXRAD data for the spring and fall
migration seasons.
In the U.S. the Doppler Weather Surveillance Radar (WSR-88D or NEXRAD) can be used to detect, quantify, and monitor biological targets in the atmosphere (e.g., bird migration, bird roosts, bat colonies, and concentrations of insects aloft). NEXRAD can be used to obtain information on the temporal and geographical aspects of bird migration in addition to quantification of avian movements. The variability in the quantity of migration over a project area for several years, coupled with the occurrence of weather conditions that cause migrants to fly at low altitudes, can be used to estimate the number of occasions per season when collision events could theoretically occur.
NEXRAD analysis provides the developer with information on:
In addition, analysts use archived meteorological data to predict the number of occasions during migration periods when weather conditions force birds to fly at low altitude where collisions risk may increase.
GMI conducted a 5-year NEXRAD analysis of avian activity to assist
in the preparation of an avian risk assessment for the proposed wind
energy project. The analysis used historical radar data to assess
bird migration patterns over the project area and surrounding
regions over a 5-year period. GMI analyzed the year-to-year,
night-to-night, hour-to-hour variation in migration density as well
as the direction of nightly movements during spring and fall
migration.