Characterizing Permeable-Pavement System Water Flow Using the Cumulative Hydrograph Model Approach

Abstract

Increased runoff rates on paved surfaces pose safety risks to city residents. Therefore, research on permeable pavement, with the goal of reducing runoff, has been growing in popularity. This study uses experimental and numerical approaches in the hydrologic design of a permeable-pavement system. The concepts of fluid flow are used to represent water flow in permeable media, and a numerical analysis is used to solve the differential equation. Thickness and porosity are the main variables in the simulation. Using a time-space model, the study finds that varying these factors has a significant effect on the characteristics of water discharge, which is illustrated using a cumulative hydrograph. The relationship between base layer properties and the initial flow delay is linear while that between storage capacity and water loss is nonlinear. Finally, a mathematical function is generated from simulation results that represent the water flow conditions, given various base layer properties of the permeable-pavement system, and can be used as a predictive function. (C) 2018 American Society of Civil Engineers.