Abstract:Based on the meteorological data of eight pilot cities for sponge city construction, the fully distributed surface water-groundwater coupled model ParFlow-CLM was applied to simulate long-term hydrological processes of an idealized bioretention catchment, and response characteristics of runoff, seepage, and evapotranspiration processes of a typical bioretention cell to meteorological conditions were systematically explored. The results indicate that the surface runoff volume of the bioretention cell is primarily influenced by the average rainfall intensity of rainfall events in the simulation year; the average rainfall intensity is also the main meteorological factor affecting the ratio of annual deep seepage to annual precipitation; when the seepage capacity of native soil at the bottom of the bioretention cell is zero (or the bioretention cell is treated with anti-seepage measures), the annual subsurface runoff coefficient shows a certain negative correlation with the average rainfall intensity of events within the year but is largely uncorrelated with annual precipitation and the ratio of annual potential evapotranspiration to annual precipitation( E p/ P ); as the seepage capacity of native soil increases, the correlation between the annual subsurface runoff coefficient and average rainfall intensity gradually shifts to a positive correlation, and a certain correlation with annual precipitation and E p/ P gradually emerges; the ratio of total evapotranspiration of the bioretention cell to annual precipitation of the catchment shows a strong linear correlation with E p/ P of the catchment.