Comparison of SWMM evaporation and discharge to in-field observations from lined permeable pavements

ABSTRACT

Limited documentation exists regarding parameterization of SWMM’s permeable pavement module and whether the output is realistic, particularly for long-term simulations. In this paper, we evaluated SWMM’s ability to replicate discharge and evaporation from three lined permeable pavement stalls. An assessment of parameter sensitivity identified the permeable pavement module’s input parameters with the highest relative sensitivity. Agreement between observations over a 1-year period and output from the calibrated model was inconsistent for 18 modelled rainfall events. While event volumes and shapes were matched relatively well for two concrete paver stalls for simple single-peak events, more complex multi-peak events showed poor agreement for all stalls. The porous asphalt stall was modelled least satisfactorily, due to its retention capacity that cannot be represented in the model. Based on the findings of this study, an evaporation coefficient (between 0.2 and 0.9), should be applied for long-term simulations of permeable pavement for best results.

KEYWORDS:

• Permeable pavement
• SWMM
• continuous modelling
• LID
• evaporation
• sensitivity analysis

Disclosure statement

No potential conflict of interest was reported by the author(s).