In this paper, we demonstrate an application of a 3D urban model derived from laser scanning data to improve the information base on how differently urban citizens are harmed by noise pollution. 3D models have a long tradition in the field of urban planning; mostly they are used for visualization purposes, but there is a lack of knowledge of spatial analyses that utilize 3D models. An increasing awareness of negative effects of environmental pollution on human health is emergent in our densely

more »

... uilt-up urban areas. European environmental standards have been introduced in the past years. The 'Environmental noise Directive 2002/49/EC' requires from the Member States to produce strategic noise maps in order to inform the public about noise exposure and its effects. Most of the noise maps that are available today and also the requested EU noise maps are in 2D indicating the noise level at a certain height e.g. 4m above ground. In reality, noise travels in all direction and is high at the source and decreases with distance to the source. Such 2D noise maps do not allow distinguishing different levels of noise pollution e.g. inhabitants of high rise buildings are affected. It is therefore the development of 3D noise maps that can show the influence of noise in all directions, which help in better understanding of how many inhabitants are threatened by noise levels hazardous to human health. Within this study a methodology is developed to build 3D noise models showing the spread of noise pollution. The method is illustrated using a 3D city model derived from laser scanning data of a small part of Delft, the Netherland. In order to model the noise levels 3D observation points (that represent the virtual microphones) are generated. The noise calculation is using the Dutch standard noise calculation models. Spatial interpolation methods are used to develop a noise surface. The results are than used to estimate the number of inhabitants possibly threaten by high noise level as well as the effectiveness of noise barriers is tested. The results show that although the number of inhabitants affected by high noise levels is approximated, the 3D noise model provides much clearer indication where standards are exceeded and allows quantification of effected inhabitants. The incorporation of noise barriers show that the model can be useful in calculating the efficiency of noise barriers. This method has a potential to improve information for urban environmental planning and management as it helps to clearly indicate hot-spots of pollution and better assess noise mitigation measures. INTRODUCTION 3D models for urban planning and management The use of 3D models (e.g. marquets) has a long tradition in the field of urban planning and design. 3D models of buildings set into a landscape are employed to assist in the decision making process to better communicate or discuss urban design issues, e.g. the (re)development of an area. Traditional marquets have the advantage to be easily understood by the audience, however drawbacks are that they cannot be viewed from different viewing angles/perspectives as well as they are isolated from their surrounding environment. The implementation of digital 3D visualizations of urban plans (using CAD or GIS environments) where the user can navigate through the urban landscape has been increasing the degrees of user interaction (Hanzel, 2007). These developments have a great potential to improve and ease the communication process between planning professionals and the community as they help in bridging the frequently observed communication friction between experts and public. Such developments are gaining importance in the context of collaborative planning in which planning professionals enable the community to come to a joined decision (Klosterman and Brail, 2002) , essential here is to develop applications that are user-friendly and easily understood. The concept of collective design and planning has been joining several ideas towards a more context sensitive approach of participatory planning (Mantysalo, 2005).