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K. Hammerberg:
"Accounting for the Role of Trees in Urban Energy Balance Modeling Using GIS Techniques";
Supervisor: A. Mahdavi; Institut für Architekturwissenschaften, Abteilung Bauphysik und Bauökologie, 2014; final examination: 2014-01-22.

This thesis work addresses the effect of trees on the urban energy
balance and examines two methods for accounting for their impact
in micro-climate modeling. The primary objective was to explore the
ways that trees influence the exchange of radiation within the urban
environment, namely the obstruction of the sky to nocturnal longwave
radiative cooling and the interception of direct short-wave
solar radiation.
In pursuit of this goal, this study employed computational methods
involving high resolution digital models of the city of Vienna, Austria.
They were used to calculate continuous sky view factor (SVF) maps
and estimate global solar radiation in urban street canyons. Both
methods were compared to on-site measurements for validation.
Additionally, the strength of the relationship between SVF and urban
heat island intensity (UHII) was also explored. In order to achieve
this, 5 urban study areas and one rural reference area were
selected. Each study area was centered around a longterm weather
station. In each area it was necessary to distill a single area mean
value of SVF from the continuous SVF maps to compare against the
UHII value. Several methods for area mean sampling were
compared in view of the strength of their relationship to UHII.

none - see english version.

Project Head Ardeshir Mahdavi:
Monitoring and modeling of the urban micro-climate