The role of urban surfaces (permeable pavements) in regulating drainage and evaporation: development of a laboratory simulation experiment

Abstract

Permeable pavements and similar stormwater control devices have not been exploited in the UK, in part because their adoption has been hindered by a lack of detailed knowledge of their hydrological performance. This paper describes a research programme that produced detailed information on the hydrological behaviour of a car park surface. The study involved the construction of full-scale permeable pavement model car park structures and a rainfall simulator for use in the laboratory. A monitoring procedure was developed in order to measure inputs and changes in drainage, storage and evaporation over short and long time-scales (2 hours to 3 months). A range of simulated rainfalls, which varied in intensity and duration, was applied to the model car park surfaces. Hydrological processes were monitored over an 18-month period. Results demonstrated that evaporation, drainage and retention in the structures were strongly in¯uenced by the particle size distribution of the bedding material and by water retention in the surface blocks. In general, an average of 55% of a one-hour duration, 15 mm h À1 rainfall event could be retained by an initially air-dry structure. Subsequent simulations demonstrated that 30% of a one-hour duration, 15 mm h À1 rainfall event could be stored by an initially wet structure (with a minimum time interval between rainfall applications of 72 hours).

Cooling effect of water-holding pavements made of new materials on water and heat budgets in urban areas

“…4). The simulation showed that the hydrothermal characteristics (water content, evaporation, drainage, and ground temperature) of these permeable pavements were strongly influenced by surface reflectance, porosity, hydraulic conductivity at saturation, heat conductivity, and soil tension at saturation of the materials, as described in previous research (Andersen et al, 1999;Sansalone and Teng, 2005). Collecting data on the various physical characteristics of the materials affecting water and heat dynamics is important if we are to reproduce actual phenomena more accurately.…”

“…This is also related to the sensitivity of saturated hydraulic conductivity and surface storage capacity of the pavements (Dupont et al, 2006;Ramier et al, 2006). It is necessary to record the heat flux budget, the water amount overflowing from the blocks, surface storage, and evaporation, in addition to the water mass in the blocks, in order to correctly evaluate the total water content and to use a lysimeter based on the water conservation of mass (Andersen et al, 1999;Ramier et al, 2004) in future work.…”

“…The construction of a full-scale permeable pavement set-up clarified that evaporation, drainage and retention in the material were strongly influenced by the particle size distribution of the bedding material and by water retention in surface blocks (Andersen et al, 1999;Sansalone and Teng, 2005). Ramier et al (2004) assessed losses due to infiltration, evaporation and runoff on asphalt, concrete and porous plates with a lysimeter and by measuring storage at the surface and in the pores of the plates, surface runoff, and evaporation and infiltration at the base of the plates.…”

A review on the development of cool pavements to mitigate urban heat island effect

“…On contrary, Andersen et al [66] found that the evaporation of this paver varied from 0.09 to 0.22 kg/m 2 /day, approximately equivalent to 9-22 W/m 2 at the midday if the evaporation at night is assumed negligible. This infers permeable pavers perform limited evaporative cooling.…”

The effects of urbanization, geographical and topographical conditions on reference evapotranspiration

“…In a study carried out in North American cities (Mexico City, Miami, Tucson, Sacramento, Los Angeles, Vancouver and Chicago), it was found that the evapotranspiration in inhabited areas is 22∼37% of net all-wave radiation, and evapotranspiration is minimal in urban centers and industrial areas. Geographical conditions, such as rivers and permeable paving, affect the increase in evapotranspiration (Unger 1999;Andersen et al 1999;Ragab et al 2003). In many cities, the amount of evapotranspiration was more than the amount of precipitation (Grimmond and Oke 1998).…”