European Cooperation in the field of Scientific and Technical Research -

COST Action C11

COST ACTION C11 - "Greenstructures and Urban Planning - Major Issues"


To aid in the identification of the Major Issues relating the link between Greenstructures and Urban Planning Sybrand Tjallingii - NL (8 Dec 00)suggests we start with the major issues as set out in the Memorandum of Understanding (click SCOPE button for full details

He draws attention to the following relevant issues:

1. State of the art

The knowledge collected and discussed during the meetings mentioned in the first section may be categorised in three fields: areas, flows and actors.

Area studiesThe relation between built-up and open space may be defined as density in terms of the amount of people, buildings or activities per surface-area. Obviously, the measured density depends to a large extent on whether density is measured by block, by district or on any other level. In relation to green areas, the built and paved surfaces and the polluting and disturbing effects of human activities are especially relevant. Current density coefficients do not always express these relevant aspects.

The quality of open spaces, however, is only partly related to the density of buildings or to functional features. Local geology, hydrology and topography, for example, have left their traces in the history of cities, and sometimes are a source of inspiration for new urban design for built-up and green areas. The interaction of these features with regular blocks and formal structures creates a variety of places and may enhance the identity of the city. 'Greenways' create interesting walks and cycle routes through the urban landscape and thus enable city dwellers to discover and enjoy the qualities and identity of their city.

In recent years more research focuses on the importance of green areas for biodiversity conservation. Suitable habitat quality and a spatial structure of green areas that connects these habitats, greatly enhances chances for achieving biodiversity objectives. In countries with intensified agricultural land use, many species take refuge to urban areas. Lack of coherence in the urban landscape not only deprives species from a life-support-system, it also impedes city dwellers to get easy access to a coherent network of green areas. Recent studies stress the importance of accessible green areas for the quality of life of city dwellers. Urban areas have been studied to identify the effects for people living in these areas and to find options for improving the conditions of the greenstructure.

Here, research focuses primarily on the interactions between traffic and waterflows and greenstructures in the context of urban planning.

Studies on traffic show increased dependency on car traffic in low density suburbs, leading to pollution, noise and fragmentation of green areas. As a result of innovative technology traffic flows will be less energy consuming and less polluting in the near future. However, fragmentation and barrier effects caused by transport infrastructure will increasingly affect the spatial quality, especially of green areas. Concentration of traffic flows in multimodal corridors is an interesting strategy that creates opportunities for noise and pollution control and for bridges and tunnels to overcome the barrier problem. The use of public transport is generally high in densely populated cities. This does not mean, however, that increasing density automatically leads to increased use of trains and bicycles. Greenways may contribute to an attractive network of cycle tracks and, in doing so, may be part of traffic strategies.

Recently,flow studies on sewage systems, rainwater and groundwater flows contributed to new urban water strategies. By providing rainwater storage green areas contribute to the implementation of these strategies. Inversely, in built up areas green areas themselves also benefit from the presence of more water and improved water quality.

Other flows such as energy and organic waste, although less important for urban planning and greenstructure, may be included in future studies.

Actor studies Actor studies firstly focus on the driving social and economic forces and the power relations behind urban development. Secondly, success and failure of planning and management practices are studied, especially in the fields of urban renewal, transport policy and the management and maintenance of green areas. These studies have already produced important insights into the role of different actors in decision making. Planning studies suggest it may be advisable to structure decision making along two lines:

Decisions about durable 'carrying spatial structures' such as greenstructures, transport infrastructure and water networks. Here a central issue is how to plan green areas and spatial greenstructures that can resist the pressure of building and road construction.

Decisions about the use of open space and green areas in urban districts. Here the dynamics of activities with relatively short life times need space and freedom.

The two lines of decision making have there own key actors and their own communication strategies. An important issue relevant to both lines is the question how to cross the disciplinary and sectoral borders that divide both researchers and practitioners.

2. Objective and Benefits

The main general objective of the proposed COST action is to reach a better understanding of the role played by planning, design and management in the interactions between green and built-up areas, improving the way green areas contribute to the quality of life of urban citizens, to the quality of habitats as a basis for biodiversity and to other aspects of sustainable urban development.


Pilot project schemes organised by the EC, the OECD and by other organisations have demonstrated the importance of comparative analysis at the project level. The present Network seeks to combine research at the project level with studies at the policy level.

It is at these two levels that researchers and practitioners from more European countries will benefit from the proposed COST Action.The benefit of comparing projects realised under different conditions is a better understanding of factors that determine success and failure of these projects. The benefit of comparing policy measures is a better understanding of the structural conditions for liveable and sustainable urban environments.

The situation in different countries and different cities varies greatly. The research publications and the discussions during the meetings of the Network underline the importance of comparative studies for a better understanding of generic lessons and of ways to do right to diversity.

3. Scientific Programme, questions

The proposed COST action will facilitate the exchange and further development of knowledge, practical experience, views, concepts and methods related to the role of greenstructures in urban planning. Against this background a framework for comparative research, a common language for analysing planning issues concerning greenstructures in different urban settings needs to be developed.

Some general and more specific questions articulate the objectives of the proposed COST action. These questions are at the basis of a planned comparative research project. Questions result from a series of seminars held by the present network. These seminars will continue to be organised and the COST action will enable them to reach a wider public and to discuss the results of a an extended comparative research programme.


The overall question is: To what extent may existing conceptual frameworks for sustainable urban development be used and improved in the context of comparative research on greenstructure and urban planning?

The framework to be developed should be useful to formulate research projects addressing a number of questions such as:

What can be learned from case studies about the interaction processes between greenstructure and urban development?And what about the contribution of greenstructures to the quality of life in cities, to the quality of habitats for biodiversity and to other aspects of sustainable urban development?

How may cities create structural spatial and organisational conditions for the quality of green and open spaces as a regular part of urban development?

What can be learned about operational instruments and methods for the management and maintenance of public open space?

What can be learned about success and failure of projects?

There is also a need to initiate thematic studies about more specific questions:

How to create and assess ecologically sound and sustainable planning and design options for urban greenstructures that are well embedded in the local situation. Such options combine environmental aspects (health, safety, biological diversity) with commercial, social and cultural aspects.

How to create good procedures for communication and decision making?

How to deal with power relations in the urban situations where green areas are in a vulnerable position?

How to create good conditions for multidisciplinary co-operation between researchers from the natural, the technical and the social sciences? And how to organise better co-operation between practitioners from different departments?

S. Tjallingi

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