The investigation of microclimate variation of urban canyons in Vienna, Austria

Abstract

As urban areas continue to develop and grow, changes will occur in the landscape, buildings, roads, and other infrastructures that can affect the microclimate of these areas. These changes may ultimately develop into a phenomenon known as urban heat island (UHI); mainly believed to be caused by the change in surface properties and geometric forms. The main characteristic of UHI is warmer temperature when compared to the surrounding rural area. UHI affect urbanized areas, both big and small, and it is a growing concern for designers, planners, scientists, and residents alike; posing a challenge for proper building design and healthy living conditions. Although past research has shown that urban geometry, such as aspect ratio or sky view factor, plays a key role, it alone cannot explain this fairly complex phenomenon. Other factors that can contribute to heat islands are the density of urban areas, sealing of urban structures, and increasing anthropogenic heat output. Even though heat islands in urban areas tend to display a typical pattern, the intensity can be quite different at each location, even in close proximity of each other. Much of this is due to the unique environmental conditions that make up an urban canyon. This research investigates the street-level climate variations in urban canyons by monitoring and comparing site-specific conditions, and analyzes them against other empirical other data sources such as stationary weather measurements. Selected contributing factors will be explored to see how these factors can have an impact on the microclimate variations of selected study areas. Since much of the past research work tended to be in North America, this research will focus on microclimatic variation due to the unique characteristics of urban canyons in Vienna, Austria.