Measuring the efficiency and intensity of the cooling impact of urban parks in Riyadh, Saudi Arabia: Seasonal analysis and proposed approach to the parks cooling direction index

Abstract

This study investigates the cooling efficiency of four urban parks in Riyadh, Saudi Arabia, utilizing Landsat 8 and 9 imagery from December 2023 to November 2024. The analysis focused on Land Surface Temperature (LST) and the Normalized Difference Vegetation Index (NDVI) to examine seasonal variations in cooling effects. Cooling efficiency, assessed within a 300-m buffer zone, varied across both seasons and parks. The highest seasonal cooling efficiency was observed in summer, extending up to 172.5 m, while the lowest occurred in winter at 127.5 m. Park-specific performance showed notable differences. Al-Wadi Park, despite its smaller size, exhibited the highest cooling efficiency, reaching 180 m, surpassing the larger King Abdullah Park at 150 m. Al-Salam Park, which had the highest NDVI, demonstrated the most significant cooling effect, with its influence extending up to 240 m in summer. Al-Suwaidi Park, on the other hand, recorded the highest overall efficiency, extending up to 300 m. In terms of spatial cooling intensity, Al-Salam Park produced the strongest cooling effects, with temperature reductions of 5.4 °C to the east and 4.7 °C to the west. Seasonal wind patterns also influenced the cooling direction, with eastward cooling being most prominent during summer. These findings challenge the conventional assumption that larger parks always provide greater cooling benefits, highlighting instead the essential role of vegetation density in urban thermal regulation. The study emphasizes the need for strategic park design that incorporates dense vegetation and water bodies to optimize cooling efficiency and mitigate Urban Heat Island (UHI) effects in arid cities.