Evaluation of the Infiltration Capacity of a Permeable Paving Block for Urban Flood Disaster Reduction

The increase of impermeable areas in urban development projects results in a decreased concentration time, the rise of the peak runoff, and the deterioration of the ability of rainfall infiltration. This study performed experiments on a permeable paving block to develop countermeasures for urban inundation. The permeable paving block has a cooling effect on heat islands in urban areas and it can be constructed in a short period. The experiments were performed under rainfall intensities of 50, 100, 150, and 200 mm/hr. The runoffs of the permeable and impermeable paving blocks were measured, and their ultimate infiltration capacities were compared and analyzed. The experiment results showed that the infiltration capacity of the permeable paving block was maintained. These results indicate that the permeable paving block can be used as a distributed detention facility to counter urban inundation. The experiment results were compared with the simulation results with the FEMWATER model to evaluate the NRCS Curve Number for each permeable paving block that has a different hydraulic permeability. Based on the evaluation results, this study presents the design criteria for permeable paving blocks in South Korea.