An Evaluation of the Infiltration Capacity of Permeable Concrete Block Pavements for Urban Flood Disaster Reduction

The impermeable areas increased by urban development results in decreased basin lag time, increased of the peak flow and deterioration of rainfall infiltration ability which may trigger flood disasters. This study performed laboratory experiments to test infiltration capacity of permeable concrete block pavements which usually used for countermeasures to reduce urban inundation and Low Impact Development. The permeable block pavements also can be used to reduce temperature of hot islands in urban areas. The various rainfall-runoff experiments was performed on the testing basin with permeable concrete block pavements in a variety of rainfall intensities such as 50, 100, 150 and 200 mm/hr. The runoffs over the permeable and impermeable block pavements were measured by the weir to analyze infiltration capacities of permeable concrete block pavements and find equilibrium condition between the occurrence of infiltration and runoff. The results show infiltration capacity was decreased as rainfall intensity was increased in both cases of permeable and impermeable block pavements. The beginning time of runoff which time needed to make an equilibrium condition between the occurrence of infiltration and runoff was increased as infiltration capacity was increased. To evaluate the NRCS Curve Number estimated from the FEMWATER model were compared with the experimental results. Through the evaluation, this study suggests regression equation to estimate NRCS Curve Number which used for assessing the impacts of constructing the disaster reduction facility. This equation can be used to set the design criteria for permeable paving blocks.