2.5 Spatial movement analysis
In this analysis, we constructed networks of premises and abattoirs
summarised by parish and then computed the Euclidean distance of the
movements (Karney, 2013) based on parish centroids (1,032 polygons).
Afterwards, we plotted the spatial movements on annual maps,
representing the source and target by a vector between parish centroids
and the direction of movement by an arrow, and added the frequency of
movements by colours: <100 green, 101–500 blue and
>500 red. From the network of premises, we summarise the
total incoming and outgoing movements and calculate their balance to
detect the most influential parishes, plotting the result on the map,
looking for the areas with higher risk of disease spread.
Using network metrics and spatial movements, we plotted images and
converted them into annual animations using six frames for every month,
showing the monthly status of the centrality network metrics. The video
sections contains A: representation of weighted origin/destiny movements
on the map, vectors are plotted according with movement weights,
parishes coloured by monthly In/Out/balance degree. B: Ingoing-outgoing
mobilised pigs (parishes codes). C: percentage of accumulated active
nodes. D: monthly movement weights. E: Active edges. Videos are
available in the supporting information.