ABSTRACT
It should be axiomatic that decisions in town planning are based on comprehensive information and appraisal of what already exists. It is evident, however, that in many towns and cities decisions that greatly affect the urban fabric, the urban landscape and urban quality of life have been made, and continue to be made, on incomplete, inappropriate, marginally relevant or partial data. Urban planning in general, environmental planning in particular, and nature conservation and amenity planning most of all should demand a comprehensive, frequently updated set of relevant information. Much of this information needs to be given a spatial framework, including distributions and distributional interrelationships. In a word, the information needs to be mapped. And these maps need to be in a format that can be accessed, reviewed, interpreted and used. In order to use the green environment as a component in the decision-making process in urban planning and, reciprocally, in order to use the planning process as an opportunity and tool in the enhancement of the green environment it is necessary to know what actually exists, what the planning and conservation goals are, and what the options are for achieving these goals. The green environment itself must be seen as including biodiversity, habitat type (biotope), habitat quality, and the structure and pattern of the landscape. Together, these components provide what might be thought of as the ‘green capital’ of the city. This green capital ranges from the presence of common and abundant species to the rare and restricted; from relict ancient woodland to small manicured lawn; from large semi-natural vegetation to tiny wasteland plots; and from integrated green networks to isolated green islands. Quantifying and mapping the green capital is essential for identifying, monitoring and assessing the consequences of planning decisions, bearing in mind that urban form and function are both inherently dynamic. Mapping has increasingly become dependent on geographic information systems (GIS) or uses expert systems such as Conservation Management System (www.esdm.co.uk) and can enable decision makers to set out appropriate goals, identify realistic choices, implement suitable environmental impact assessments, and monitor results.
