One aspect of the behaviour of the geese as discussed here seems to concentrate on them having been disturbed and subsequently taking flight into the path of aircraft taking off, however it seems likely that these particular birds were in transit through the zone. No amount of ground patrols or scaring measures would affect these birds from following their long-established migratory routes.
Geese do move locally from roosts to feeding grounds and it is maybe this behaviour that should be studied with respect to this incident, in particular the times of day when these 'local' flights (of the geese) occur.