Fig. 4

Stability of incidence by seasons and soil type (The level of stability in the early seasons is superimposed on the soil type. There are two soil types in our study area (medium-fine and fine). Depending on the season, the zone with the medium-fine soil type has an incidence stability of about 50%, while the zone with the fine soil type has an incidence stability of no more than 20%, regardless of the season)