Abstract
Urban environmental measurements and observational statistics should reflect the properties generated over an adjacent area of adequate length where homogeneity is usually assumed. The determination of this characteristic source area that gives sufficient representation of the horizontal coverage of a sensing instrument or the fetch of transported quantities is of critical importance to guide the design and implementation of urban landscape planning strategies. In this study, we aim to unify two different methods for estimating source areas, viz. the statistical correlation method commonly used by geographers for landscape fragmentation and the mechanistic footprint model by meteorologists for atmospheric measurements. Good agreement was found in the intercomparison of the estimate of source areas by the two methods, based on 2-m air temperature measurement collected using a network of weather stations. The results can be extended to shed new lights on urban planning strategies, such as the use of urban vegetation for heat mitigation. In general, a sizable patch of landscape is required in order to play an effective role in regulating the local environment, proportional to the height at which stakeholders’ interest is mainly concerned.
Highlights
Built environments are excessively warmer than their rural surroundings, a prominent phenomenon known as the “urban heat island” (UHI) effect [1, 2]
The agreement between the two methods is reasonably good. Both methods estimate that for the recorded daily maximum air temperature, the maximum contribution is from a source area of around 200 m × 200 m for vegetated and impervious surfaces
This is physical in that urban vegetation tends to mitigate the maximum air temperature by evapotranspirative cooling, whereas the impervious surfaces contributes positively to urban warming
Summary
Built environments are excessively warmer than their rural surroundings, a prominent phenomenon known as the “urban heat island” (UHI) effect [1, 2]. The energetic basis of UHI can be attributed to multiple factors, including modified land surface hydrothermal properties, radiative trapping by buildings, modified aerodynamic roughness, reduced evapotranspiration, and anthropogenic heat release [3,4,5,6,7]. Among these contributors, the use of engineered materials, such as concrete, asphalt, brick, etc. The increase of impervious land cover fractions, together with the rapid urbanization observed in the last few decades [8], has altered the flow patterns of thermal energy in the integrated soilland-atmosphere continuum [1, 9]. The minimum temperature of Phoenix metropolitan, AZ has experienced an increase of 5.5 ̊C from the late 1940s, and a continuously decreased cooling rate during nighttime due to urban expansion [10, 11].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
