A microscale UV radiation model for urban environments

Model description and evaluation based on measurements

authored by

Matthias Sühring, Sebastian Lorenz, Helge Knoop, Katrin Frieda Gehrke

Abstract

Exposure to UV radiation can have serious consequences for human health, as UV radiation can damage DNA, can cause severe damage to skin and eye, is carcinogenic and is the main cause of skin cancer. To prevent UV-related health impacts, a reduction of UV exposure is an effective way. In order to allow urban planners to effectively mitigate UV exposure within built-up environments, we have developed an UV radiation model and implemented this into the microscale urban model PALM. The model considers shading of direct and diffuse radiation components by buildings, trees and sun-protection devices. Furthermore, transmission of UV radiation through tree crowns is considered, as well as multiple reflections between mutually visible urban surfaces with material-specific albedo in the spectral UV range. The incoming UV radiation at the top of the urban layer is provided by a coupled atmospheric radiation transfer model. This allows to study the effectiveness of UV mitigation strategies for different atmospheric UV scenarios such as clear-sky or cloudy conditions, or for different ozone-layer thicknesses. To evaluate the urban UV model, we compared the model results with spectral and broadband UV measurements carried out in a complex and partially shaded environment. We show that the model represents the spatio-temporal heterogeneity of UV radiation in such environments sufficiently well. Moreover, we performed a sensitivity study for specific parameters such as surface albedo, leaf area density or the tree-absorption coefficient to assess the uncertainty in modeled UV radiation due to usually poorly known model input parameters.

Organisation(s)

Institute of Meteorology and Climatology

External Organisation(s)

Pecanode GmbH
Federal Office for Radiation Protection (BfS)

Type

Article

Journal

Building and environment

Volume

278

ISSN

0360-1323

Publication date

11.04.2025

Publication status

E-pub ahead of print

Peer reviewed

Yes

ASJC Scopus subject areas

Environmental Engineering, Civil and Structural Engineering, Geography, Planning and Development, Building and Construction

Sustainable Development Goals

SDG 3 - Good Health and Well-being

Electronic version(s)

https://doi.org/10.1016/j.buildenv.2025.112961 (Access: Closed)