Surface Temperature, Heat Loading and Spectral Reflectance of Artificial Turfgrass.
Dale Devitt1, Malika Baghzouz2, Brian Bird2, and Michael Young3. (1) University of Nevada - Las Vegas Library, University of Nevada-Las Vegas, 4505 S. Maryland Parkway, MS4004, Las Vegas, NV 89154-4004, (2) University of Nevada - Las Vegas, School of Life Sciences, 4505 S. Maryland Parkway, MS4004, Las Vegas, NV 89154-4004, (3) Desert Research Institute, Desert Research Institute, 755 E. Flamingo Rd., Las Vegas, NV 89119
In the arid southwest artificial turfgrass is being considered as a water conserving alternative to living turfgrass for sporting fields and parks. However, a potentially significant undesirable characteristic of artificial turfgrass is the elevated surface temperatures that occur during daylight hours. The objective of this study was to examine the factors that influence surface temperature rise of artificial turfgrass (Geneva “Grid Iron Supreme”). The data collection included: surface temperature, spectral reflectance, solar radiation and air temperatures associated with different landscape covers and artificial turfgrass components; and, an assessment of energy loading and heat transport through artificial turfgrass. The study was conducted in Las Vegas, NV. Results showed surface temperatures on green artificial turfgrass with black rubber infill as significantly higher (p<0.05) than white artificial turfgrass, asphalt, bare soil, concrete, and living turfgrass, with maximum surface temperatures of 76oC. Solar radiation accounted for most of the variation in surface temperature of the green artificial turfgrass (r2=0.95, p<0.001) as opposed to air temperature (r2=0.32; p<0.05). Spectral reflectance measurements showed green artificial turfgrass reflecting less than 10% of incoming radiation (wavelengths ranging from 350-2500 nm). Average reflectance in the near-infrared region (701-1300 nm) was shown to be significantly correlated with surface temperature of different landscape surfaces (R2= 0.62, p<0.05). Soil heat flux through the artificial turfgrass matting accounted for less than10% of incoming solar radiation. We recommend that similar measurements be made on other products before installation. Our data would also support the development of empirical relationships between solar radiation and surface temperatures as a way of managing when recreational fields can be safely used.