HOW URBAN DEVELOPMENT CONTRIBUTES TO THERMAL ENVIRONMENT VARIATION ---- A CASE STUDY IN NEW YORK CITY

Abstract

The urban anthropogenic heat flux (AHF), which is one integral part of the deteriorating urban thermal environment, is seldom discussed for its ambiguity to accurately measure over heterogeneous land surfaces. Here, relying on remote sensing technology and meteorological models, AHF is estimated and illustrated on April 18, 2017 over NYC area. Furthermore, a few independent variables are developed in order to possibly explain the variations of anthropogenic heat flux, including road density, impervious surface area percent, building shape coefficient, standard deviation of building height and street canyon aspect ratio. On both community district and census tract level, four of the five variables (road density, impervious surface area percent, standard deviation of building height and street canyon aspect ratio) demonstrate steady significant linear relationships with anthropogenic heat flux. A final spatial error model suggests that 71.8% of AHF variation can be explained after spatial error term was incorporated. The results implicate that some planning and designing indices associated with urban developments like buildings and roads should be taken into consideration for a benign thermal environment. In this case, a compact sub-city level spatial unit with diversified building heights and minimum exploitation to pervious land is a good example in terms of AHF mitigation.