Seasonal climatic effects on the hydrology of a rain garden.

The article investigates the effect of cold climatic conditions on the hydrology and performance of the rain gardens located in Trondheim, Norway. Measurements and comparisons of the hydraulic detention, storm lag time and peak flow reduction showed no significant difference between seasonal lag time, however, a decreasing trend in lag time between rain, rain-on-snow and snowmelt was seen. Results also showed that there was a positive correlation between the time since the last wetting event and lag time, and between air temperature and hydraulic detention. Findings suggest that the time between events and seasonal air temperatures are key parameters in the hydraulic performance of cold climate rain gardens.