Variation of the water production rate near perihelion under the dust layer removal model for different combinations of dust particle size and porosity. Each panel shows simulation results for a specific particle size (1 mm or 0.1 mm) and three porosity values (0.6, 0.7, and 0.8), as indicated in the bottom-right corner of each subplot. The vertical dashed line marks the time of perihelion passage (x=0). The insets highlight the detailed structure of cyclic dust removal activity near perihelion. In each panel, the upper and lower insets correspond to cases from Fig. 2 that exhibit sustained activity across perihelion and those in which dust removal ceases before perihelion, respectively.