1. Summary

The development of URBIS, a management system for air pollution and noise, started with an analysis of demand and supply of environmental data. Based on this, a prototype was defined, implemented and applied to Leiden, the pilot city. Much emphasis was given to generate from the numerous data of both municipal and national origin the detailed input needed for high resolution air quality calculations, which allowed to generate maps and overviews of the spatial distribution including hotspots.
 
 

2. Aim of the research

The purpose of the work is to integrate the existing environmental data, models and standard calculation procedures in the Netherlands together with a Geographical Information System (GIS) into a comprehensive urban management system for air pollution and noise (URBIS), matching the demands of information and supply of data as well as possible (Fig. 1). Much emphasis is given to integrating a city-scale model with micro-scale (streets, small business) models. The methodology has to be proven to be practicable in the city of Leiden. The output of URBIS includes maps and tables presenting emissions, air pollution, noise and corresponding risks to policy makers, citizens and others.
 
 
 
 

Info supplies Info demands

Fig. 1 The project aims to match the supplies and demands of data on municipal air pollution
 
 
 
 

3. Activities during the year

The project is divided into two phases: the development of a prototype and of an improved version. By the end of 1998 the following main activities had been completed:

• Inventory of information demands by all relevant actors,
• Definition of the prototype,
• Implementation and application of the prototype,
• Evaluation workshop and definition of improvements.

Fig. 2 Sketch of URBIS
 
 
 
 

4. Principal results

Information and tools: demand side

A uniform picture of the needs of environmental authorities can not be given. Interviewed personnel in some municipalities appeared not much interested in air pollution matters, which could be interpreted as either the cause or the consequence of the lack of possibilities to generate air quality information. Other municipalities on the other hand definitely do have a need of comprehensive information on local air pollution and feel that this is currently lacking.

The municipal department and politicians of the pilot city of Leiden said to need this information primarily for their own use: to have general insight, to identify hotspots, for planning purposes. They recognise also the potential for public information but one has a cautious attitude since information could be misinterpreted. Authorities of higher administrative levels (Province, Ministry, European Commission) have a need to monitor the developments in municipalities. Particularly at the EU level detailed information is regarded as important for compliance checking and to involve the public.
 
 

Information and tools: supply side

Although many relevant data exist, both at the national level (e.g. emission registration) and the local level (e.g. licences), most of these data are not suitable for the development of detailed city air quality maps. Emission data on small and medium-sized businesses are almost completely absent at the local level, whilst straightforward use of national emission data for this section hardly gives useful results for local authorities. The existing models proved to be difficult to link due to basic differences in their logical structure. A model for the intermediate scale (30-300m) is lacking.
 
 

Methods in URBIS for the calculation of air quality

The work to develop and implement a methodology could be carried out largely according to the original expectations. Compared with the original anticipation’s, two deviations should be noted:

• The computational burden associated with the high resolution (25 m, and near source even better) was expected to be high, and turned out even larger.
• In spite of the huge amount of data in permits of small and medium-sized businesses emission data were virtually absent. Much effort, in particular by personnel of the Municipality of Leiden, was spent to explore possible solutions. Together with emission experts of TNO, a methodology for a first estimate has been developed and applied. Also an improvement step was developed and applied, but the yield of this step is as yet poor.

Usefulness of the methodology

Although a final judgement on the usefulness of URBIS could not yet be given, the comments by the potential users in the evaluation workshop were very positive. A potential problem from the viewpoint of local policy makers was also noted: it may be difficult to manage the public response to environmental maps, which may be irrational, especially if risk estimates are presented (even when the risks are low). From the viewpoint of national authorities the approach was considered to be very promising because of the quantitative nature of the results and the possibilities to aggregate the results to the national level.
 
 

5. Main conclusions

The air quality information that is preferred depends on the administrative level. Important goals are to provide insight and overview, to identify problems, to quantify and monitor progress, to set priorities, to plan city development, to inform the public and to raise awareness. Data on air quality were often deemed more relevant than data on emissions or risks.
 
 

Within Dutch municipalities there are numerous relevant data, but most of them, having been collected for other purposes, are difficult to use. Assistance by the municipality is needed to render the data available. Data vary per municipality. Methods to calculate air quality near small and medium-sized businesses tend to be either too coarse for municipal use or too detailed to calculate overviews. Micro-scale models are needed for hotspots and exceedances of limit values, but the coupling of city-scale and micro-scale models is not trivial. Finding a balance between the desired spatial resolution and computational burden is a major task.
 
 

6. Aim for the coming year

In the next year the improvements will be implemented in the prototype and applied to the pilot city. Calculation will be carried out for the current situation and for scenarios. On the basis of the results the URBIS methodology will be evaluated by the users and by scientists.
 
 

7. Acknowledgements

This work funded by the LIFE program, the Netherlands’ Ministry of Environment and the Province of South-Holland. The city of Leiden substantially contributed to the work.
 
 

8. References

Several interim reports have been written in the Dutch language.