Estimating the velocity and direction of African Swine Fever spread in wild boar populations in South Korea using Trend-Surface Analysis
Fig 2
Predicted progress in trimesters of ASF cases in South Korea using a fourth-order polynomial trend-surface analysis.
The star marks the grid cell where the first ASF notification in wild boar was reported. Arrows show the direction of each grid cell centroid obtained from the vectors contributing to the slope of disease spread. White areas represent ASF-free administrative units in South Korea until August 2022. Administrative boundaries are republished from [27] under a CC BY 4.0 license.