Geographical Information Systems (GIS) for landscape architecture

• ‘Geographical’ reminds us that it deals with geographical, or spatial, data.
• ‘Information’ reminds us that a GIS is a way of handling data – it is a spatial database.
• ‘System’ reminds us that it dates from the 1970s, when everything to do with computers was described as a ‘system’.

Most of the world’s mapping agencies are now using GIS to produce their maps, even if they are then sold on paper. For landscape architects, GIS will be the key software tool. CAD programmes and image editing software will be ways of inputing data to the GIS. Ian McHarg’s Design with nature helped launch GIS. There is a discussion of the role of GIS in landscape and planning in Turner, T. City as landscape (1996).

GIS has become one of the major business, and military, software technologies. Happily, it can also be a design and planning tool. Each tool one uses affects the end product. One can cut wood with a saw, a plane or a chisel. One can make landscape design proposals with a spade, a pencil, modelling tools, a CAD programme – or a GIS. We should expect that each the new tool will allow different types of proposal to be made.

If you take a city plan and draw over it with a green marker pen, you can design an ‘open space system’ with parks and parkways. This is what Patrick Abercrombie did for London in 1943. It is still the foundation of open space planning for London. But what does the green ink actually mean:

• a network of parkland owned and managed by a local authority?
• a network of land with public access?
• a network of land which has not been built upon (including paved areas? Including roads?)
• a network of vegetated space (including private gardens and nature reserves?)

The ‘parkways’ on the original Abercrombie plan are a case in point. Although they were used to interconnect parks, they were actually a special category of road with wide vegetated margins.

These considerations force us to the conclusion that simply classifying land as ‘greenspace’ is inadequate. We need to:

• define areas of land (eg as ‘greenspace’)
• specify which policies apply to different parts of the greenspace (eg ‘accessible’, ‘vegetated’, ‘managed as parkland’, ‘managed as nature reserve’, ‘solid’, ‘void’)

With paper plans, this is not an easy task. With a GIS, it is simple. The two most characteristic features of a GIS are:

• maps
• database tables, from which the maps are generated

The database can hold much of the data which landscape architects use: soils, geology, water, user preferences, contours etc etc. You can either purchase the data or you can put it in yourself. It can generate 3-D models and generate aerial photographs over them, with geographic precision. But this is difficult.

Environmental Systems Research Institute (ESRI) is a GIS supplier. The organisation was started by a landscape architect and it is now the world’s largest GIS company. They make several two basic products:

• ArcView: a comparatively easy-to-use programme
• ArcInfo: a very sophisticated programme
• ArcGIS: incorporates ArcView but is scalable to include the functionality of ArcInfo

The published manuals are short and very similar to the help files on the system. The other main methods of learning about a computer programme are:

• Trial and error – this is the key method for GIS. It gives you nuggets of knowledge which soon agglomerate with other nuggets.
• Ask other users of the programme (fellow students, tutors, friends etc). They can provide you with a quick fix but the knowledge tends to be easy-come, easy-go.
• Reading ‘third party’ books. Usually, they are much more digestible than manuals.
• Using the online Help system supplied with the software.

[Note a booklet on Public open space planning and management with GIS was published by the University of Greenwich in 1998 ISBN 1 861661002. It was written by Tom Turner and Bryan Bowen and is available for £10.00 (includes postage and packing) from The Secretary, School of Architecture and Landscape, Oakfield Lane, Dartford, Kent, UK, DA12SZ). We are pleased to exchange copies of this publication for your publications.]

Links

Cadcorp supply an interesting GIS system which makes extensive use of data drawn from other programmes (eg Microsoft Access) http://www.cadcorp.co.uk/

ESRI supplies ArcView and ArcInfo in the UK http://www.esriuk.com/. This is the GIS company which was founded by a landscape architect (Jack Dangermond). The esri.com website has an account of a landscape planning project in Portugal: LANDSCAPE CAPACITY EVALUATION AND VISUAL IMPACTS SIMULATION A GIS APPROACH

MapInfo supply a popular desktop GIS system http://www.mapinfo.com/

The University of Edinburgh provides an excellent set of links to GIS-related websites http://www.geo.ed.ac.uk/home/giswww.html