Analyses of Thermal and Spectral Characteristics of Artificial Turf and Natural Grass in Las Vegas Valley

This thesis presents a comprehensive analysis of the thermal and spectral characteristics of Las Vegas Valley (LVV). The first objective examines the effects of artificial turf on the urban thermal environment in the LVV by analyzing the impact of Land Surface Temperature (LST) and surface albedo at 26 ROIs that transitioned from natural to artificial turf, alongside another 26 ROIs that remained unchanged between 2018 and 2022 utilizing available Landsat 8 satellite images for the respective years. In the comprehensive comparison of ROIs over the two years in question, it was observed that transitioning to artificial turf correlated with elevated surface temperatures, but only during the warmer months. Two series of paired T-Tests results, taking the combined annual and seasonal data, revealed significant differences on the LST of the transitioned ROIs indicating turf transition had substantial impact on LST for these ROIs. The albedo values for sites with natural grass remained relatively unchanged between the two years. Conversely, a notable decrease in albedo was observed in most sites that transitioned to artificial turf. The T-Tests revealed significant differences in albedo between 2018 and 2022 for these transitioned sites. The second objective examined the spectral signatures of 26 transitioned ROIs in both 2018 and 2022 by creating spectral signature curves and analyzed Normalized Difference Vegetation Index (NDVI) at both transitioned and non-transitioned ROIs in both years by creating the NDVI maps. For the spectral signatures, the 2018 curves had features indicative of natural grass, while the 2022 curves did not show these traits. The most evident distinction was in the SWIR1 region's reflectance, with opposing slope directions in the two years. Interestingly, despite being plastic, the synthetic turf exhibited increased reflectance in the SWIR1 region, possibly due to surface temperature effects. Average reflectance values of all 26 ROIs of each month of 2018 and 2022 at each wavelength displayed distinct curves for each year. Two sets of paired T-Test results, one for each month and the other for each ROI, presented significant differences in the reflectance values between 2018 and 2022 due to the turf transition. Distinct NDVI values and curves were obtained for artificial turf. T-Test results confirmed the significant differences on NDVI due to the turf transition as well. The entire analysis for the first and second objectives was conducted using GEE and ArcGIS Pro, with statistical assessments carried out in R-Studio. This thesis includes an additional chapter that examines the health and environmental effects of artificial turf. It covers issues such as the use of recycled tire crumb as infill, the presence of microplastics in turf components, and the composition of turf fibers. It also addresses health risks like Methicillin-Resistant Staphylococcus Aureus (MRSA) infections, heat-related illnesses, and various injuries that athletes might suffer on artificial playing surfaces. On the environmental side, the focus is on the higher temperatures of turf surfaces, ecological damage from toxic substances, and a greater risk of flooding. The thesis suggests that the decision to install artificial turf should be tailored to the unique conditions and requirements of each location. Studying the impact of artificial turf on the urban thermal environment of LVV can be helpful for informed urban planning and policymaking, aimed at creating a healthy and comfortable urban environment, especially considering the unique climate challenges of the region.