Table 1 

Environmental factors remained after Discriminant Analysis. 

Year 
Variable 
Classification function coefficient 
Eigenvalue 
BG with WNV/BG without WNV 
Grouping accuracy 


2002 
Percentage of agriculture 
0.143 
0.226 
46/612 
86.90% 


Total length of streams 
0.001 



Total size of wetlands 
0.001 



Constant 
2.124 



2003 
Percentage of agriculture 
0.126 
0.202 
35/623 
84.80% 


Total length of streams 
0.001 



Constant 
1.336 



2004 
Percentage of agriculture 
0.154 
0.201 
25/633 
84.80% 


Percentage of water 
0.037 



Mean slope 
1.908 



DEM variation 
0.049 



Constant 
4.261 



2005 
Percentage of agriculture 
0.232 
0.24 
36/622 
90.30% 


Total size of wetlands 
0.001 



Constant 
2.499 



2006 
Total size of wetlands 
0.001 
0.157 
29/629 
85.30% 


Human population density 
0.001 



Constant 
2.141 



2007 
Percentage of agriculture 
0.051 
0.195 
16/642 
88.90% 


Total length of streams 
0.001 



Percentage of water 
0.205 



Distance to the closest pollutant 
0.001 



Distance to the closest waste industry 
0.003 



Constant 
4.709 



Their coefficients, eigenvalue, the numbers of census blockgroups with mosquito WNV cases and without WNV cases, and grouping accuracies. 

Liu et al. International Journal of Health Geographics 2008 7:66 doi:10.1186/1476072X766 