For the neighbourhood scale a decomposition of the urban heat island (UHI) intensity (Delta T) into its contributing processes is suggested. The approach translates individual terms of the energy balance (radiation, evapotranspiration, heat storage, and convection) into temperature increments. This is exemplified using micrometeorological simulations (ENVI-met) for the quarter Bayerischer Bahnhof in Leipzig, Germany, under different wind conditions. In result heat storage and convection provide the principal contributions to UHI. The mapping of Delta T-contributions in a neighbourhood is a new tool facilitating the development of tailored measures for reduction of and adaptation to urban heat. For example, the Delta T-contributions (-6.8, -2.6, -9.2, and 15.7 K, respectively) calculated for a courtyard compensate each other. Applying this decomposition at each individual location, suitable adaptation measures can be developed. Considering the superposition of all local Delta T-contributions can support a cost-benefit analysis creating optimal recommendations for city planners.
Hertel, D; Schlink, U
Decomposition of urban temperatures for targeted climate change adaptation
Environmental Modelling & Software