Table 1.

Parameters of 1 km resolution transmission risk equations including the range of values, approach for sensitivity analyses, and reference for each.

Parameter	Description	Value range for 1 km (mean, SD)	Value range for 30 km	Notes (Reference)
Pte	Terrestrial poultry density	0–9418 (379.4, 745.7) chickens/km2	0–5871 chickens/km2	Chicken densities for China (25 )
Paq	Aquatic poultry density	0–2796 (86.2, 164.7) ducks and geese/km2	0–2796 Ducks and geese/km2	Duck and goose densities for China (25)
WEF	Effective waterfowl population	WEFbr: 0–0.32 (0.01, 0.04)	Wprbr: 0–0.29	Distributions from (Prosser, in review)
	Breeding season: WEFbr	WEFwi: 0–0.39 (0.006, 0.025) watefowl/km2	Wprw i 0 to 0.39	Population estimates from (43 , 44 )
	Wintering season: WEFwi			Prevalence rates from (45–49)
Cte	Contaminant containment, terrestrial poultry (biosecure threshold Pte = 5000 birds/km2)	Biosecure = 0.75 and 0.25; non-biosecure = 1 (unitless)	Biosecure = 0.5; non-biosecure = 1	Biosecure threshold of 5000 chickens per km2. Reduction of population by 0.25 or 0.75 given biosecure designation
Bte	Biosecurity, terrestrial poultry thresholds: Pte ≤ 50: Pbackyard = Pte × 1.0 50 < Pte ≤ 1000, Pbackyard: Pte × 0.5, Pte > 1000, Pbackyard = 1000	Pte × Bte = 0–1000 poultry/km2	Pte × Bte = 0–1000 poultry/km2	Tri-part equation: At densities ≤ 50, 100% of population is backyard poultry From 50 to 1000, half are backyard poultry At greater than 1000, backyard poultry is limited to 1000
Vte	Viral shedding rate, terrestrial poultry	101.4 and 109.8 EID50	100, 109.8, 106.8 EID50	Viral shedding rates per individual per day from (50–52)
Vaq	Viral shedding rate, aquatic poultry	101 and 105.7 EID50	0, 106.5, 102.98 EID50	Viral shedding rates per individual per day from (53–57)
Vwf	Viral shedding rate, wild waterfowl	102.5 and 106.5 EID50	102.5, 106.5, 104.77 EID50	Viral shedding rates per individual per day from (58)
U	Viral uptake = consumption rate of virus in the environment/minimum load for infection	10−15/(104.7–101.8) EID50	1.58e−17, 1.99e−20, 1.99e−20 ∑50	Consumption rate of virus in environment 10-15 (37); minimum viral load of 104.7 EID50 (and 101.8 EID50) to initiate infection with low pathogenic AIV (23, 59, 60)