An urban micro-climate model for assessing impacts of Water Sensitive Urban Design

Adaptation strategies for urban areas facing impacts of longer duration heatwaves and temperature extremes can benefit from the stormwater retention and increased urban vegetation associated with water sensitive urban design (WSUD). In addition to providing a more resilient water supply, micro-climate side-effects on urban areas can include cooling from evapotranspiration, increased soil moisture, and shading from vegetation.

Currently, lacking a suitable openly available micro-scale model, and without resorting to computationally intense computational fluid dynamics (CFD) methods, it has not been possible to model WSUD effects at a micro-scale level. Accurate modelling at this scale relies heavily on resolving latent energy fluxes (Grimmond et al. 2010) from vegetation, water features, and soil and pervious surfaces, while calculation of human thermal comfort (HTC) requires accurate predictions of air and surface temperatures, humidity, and wind speed at high resolutions.

A new model, TUF-3D/MAESPA, addresses this gap by embedding functionality of the MAESPA model (Duursma & Medlyn 2012), which can model individual trees, vegetation, and soil components of an urban canyon, within the TUF-3D (Krayenhoff & Voogt 2007) urban micro-climate model. Validations of this new model, using observations from a Melbourne street trees observation campaign (White et al. 2012) and street tree physiological response data (Gebert et al. 2012), show the addition of latent energy fluxes, soil hydrology, plant physiology, and vegetation shading effects increases the model's accuracy and makes it suitable to model the micro-climate impacts of WSUD features.Abstract 234030 modified by 203.166.228.240 on 7-29-2013-->