Table 2.
Summary of environmental variables used in the analysis of highly pathogenic
avian influenza (HPAI) H5N1 occurrences in wild birds in Europe.
| |
| |
|
Category |
Description of variables |
Abbreviation |
Unit |
| |
|
Anthropogenic environmental variables |
Distance to the nearest city |
City |
km |
|
Distance to the nearest metropolis |
Metro |
km |
|
Distance to the nearest road |
Road |
km |
|
Distance to the nearest highway |
Highway |
km |
|
Distance to the nearest railway |
Railway |
km |
|
Human population density in 2005 |
Hpopden |
p/km2 |
|
Poultry density in 2005 |
Poultryden |
p/km2 |
|
Physical
environmental
variables |
Distance to the nearest lake or wetland |
GLWD |
km |
|
Distance to the nearest Ramsar site |
Ramsar |
km |
|
Digital elevation model |
DEM |
m |
|
Slope aspect |
Aspect |
° |
|
Slope gradient |
Slope |
° |
|
Mean annual potential evapotranspiration |
Mapet |
mm/km2/year |
|
Mean annual aridity index |
Maaridity |
No unit |
|
Mean monthly precipitation |
PrecJan to Dec |
mm |
|
Mean monthly minimum temperature |
TminJan toDec |
°Cæ*10 |
|
Mean monthly maximum temperature |
TmaxJan to Dec |
°Cæ*10 |
|
Monthly NDVI |
NDVIJan to Dec |
No unit |
|
|
Interaction variables |
Poultry density * distance to the lake or
wetland |
PoultrydenW |
No unit |
|
Poultry density * distance to the Ramsar
site |
PoultrydenR |
No unit |
|
| |
|