Figure 4

Percentage reduction in R₀ across the river Severn (A) and the Solway Firth (B) due to their presence. For every farm i, we calculate 1 - ∑ _j S _j K(r_i,j)/∑ _j S _j K(e_i,j), where j is in the set of all farms within 10 km of i and on the opposite side of the estuary to it, S _j is the susceptibility of farm j given by S _j = N_s,j+ 10N_c,j[5] and e_i,jis Euclidean distance and r_i,jis shortest route. These values are Gaussian smoothed over a 5 km radius and then averaged. Blue: water, green: no farms.