CSS Forums - Urban planning and GIS

[B]URBAN PLANNING AND GIS[/B]
Urban planning is one of the main applications of GIS. Urban planners use GIS both as a spatial database and as an analysis and modelling tool. The applications of GIS vary according to the different stages, levels, sectors, and functions of urban planning. With the increase in user-friendliness and functions of GIS software and the marked decrease in the prices of GIS hardware, GIS is an operational and affordable information system for planning. The main constraints in the use of GIS in urban planning today are not technical issues, but the availability of data, organizational change, and staffing.
[B]THE USE OF GIS IN URBAN PLANNING[/B]
• GIS were developed in the late 1960s, yet in the early days very few planning departments installed them because of the prohibitive cost of hardware and the limited capabilities of the software.
• Most of the early software systems focused on computer mapping with few analytical functions.
• The subsequent fall in the prices of hardware, computer storage, and peripherals, accompanying improvement in the performance of hardware and software and advances in the data structures and related algorithms of vector-based GIS has made GIS more affordable, less time consuming and more workable.
• Since the early 1980s, there has been a marked increase in the installation of GIS in different levels and departments of urban and regional governments in the developed countries.
• With the further decrease in the price of computer hardware and software, the use of GIS has emerged in urban planning in the developing countries in the 1990s.
• GIS is just one of the formalised computer-based information systems capable of integrating data from various sources to provide the information necessary for effective decision-making in urban planning.
• Other information systems for urban planning include database management systems (DBMS), decision support systems (DSS), and expert systems. GIS serves both as a database and as a toolbox for urban planning.
• In a database-oriented GIS, spatial and textual data can be stored and linked using the georelational model. Planners can also extract data from their databases and input them to other modelling and spatial analysis programs. When combined with data from other tabular databases or specially conducted surveys, geographical information can be used to make effective planning decisions.
• As a toolbox, GIS allows planners to perform spatial analysis using geoprocessing functions such as map overlay, connectivity measurement, and buffering. Of all the geoprocessing functions, map overlay is probably the most useful tool. This is because planners have a long tradition of using map overlay in land suitability analysis which is itself an important component in urban planning.
• The many benefits in using GIS in urban planning include:
 improved mapping – better access to maps,
 improved map currency, more effective thematic mapping, and reduced storage cost;
 greater efficiency in retrieval of information;
 faster and more extensive access to the types of geographical information important to planning and the ability to explore a wider range of ‘what if’ scenarios;
 improved analysis;
 better communication to the public and staff;
 improved quality of services, for example speedier
 access to information for planning application processing.
[B]THE USE OF GIS IN DIFFERENT FUNCTIONS AND STAGES IN URBAN PLANNING[/B]
• Urban planning involves many functions, scales, sectors, and stages.
• In general, the functions of urban planning can be classified into general administration, development control, plan making, and strategic planning. General administration and development control are relatively routine planning activities, whereas plan making and non-routine strategic planning are undertaken much less frequently.
• The scale of the planning area covered can range from a whole city, to sub-region of a city, a district, or a street block.
• The most frequently involved sectors of urban planning are land use, transport, housing, land development, and environment.
The more routine general administration and development control work of urban planning includes:
● management of land use records;
● thematic mapping;
● planning application processing;
● building control application processing;
● land use management;
● land availability and development monitoring;
● industrial, commercial, and retail floor space recording; recreational and countryside facility planning;
● environmental impact assessment;
● contaminated and derelict land registers;
● land use/transport strategic planning;
● public facilities and shops catchment area and accessibility analysis;
● social area and deprivation analysis.
[B]Resource inventory[/B]
Geographical information, when integrated with remote sensing, can save time in collecting land use and environmental information. Remote sensing images are becoming an important source of spatial information for urban areas. They can help to detect land use and land use changes for whole urban areas.
[B]Analysis of existing situations[/B]
GIS can help to store, manipulate, and analyse physical, social, and economic data of a city. Planners can then use the spatial query and mapping functions of GIS to analyse the existing situation in the city. Through map overlay analysis, GIS can help to identify areas of conflict of land development with the environment by overlaying existing land development on land suitability maps. Areas of environmental sensitivity can be identified using remote sensing and other environmental information.
[B]Modelling and projection[/B]
A key function of planning is the projection of future population and economic growth. GIS can be used for prediction and projection. Spatial modelling of spatial distributions makes it possible to estimate the widest range of impacts of existing trends of population, and of economic and environmental change. For example, a range of environmental scenarios can be investigated through the projection of future demand for land resources from population and economic activities, modelling of the spatial distribution of such demand, and then using GIS map overlay analysis to identify areas of conflict. Using socioeconomic and environmental data stored in GIS, environmental planning models have been developed to identify areas of environmental concern and development conflict.
[B]Development of planning options[/B]
Land suitability maps are very useful in the development of planning options. They can be used to identify the solution space for future development. The association of spatial optimisation models with GIS can help to formulate and develop planning options which try to maximise or minimise some objective functions. The simulation of different scenarios of development with GIS can help in developing planning options.
[B]Selection of planning options[/B]
The final selection of a planning option is increasingly a political process, but planners can provide technical inputs to this process in order to help the community in making their collective choices. The integration of spatial and non-spatial models within GIS can help to evaluate different planning scenarios
[B]Plan implementation[/B]
GIS can be used in the implementation of urban plans by carrying out environmental impact assessment of proposed projects to evaluate and minimise the impact of development on the environment. Following such work, remedial measures can be recommended to alleviate the impacts.
Plan evaluation, monitoring, and feedback
When used together with remote sensing, GIS can help to monitor the environment. It can, for example, be used to monitor land use changes. It can also examine whether land development is following the land use plan of the region, by overlaying a land development map produced from the analysis of remote sensing images on the land use plan. In addition, GIS can be used to evaluate the impact of development on the environment to see whether adjustments of the plan are needed. GIS can also be used in the monitoring and programming of land development.
[B]FACTORS INFLUENCING THE USE OF GIS IN URBAN PLANNING[/B]
[B]Organisation[/B]
No matter how sophisticated and advanced it is, a decision support system is useless if it is not being used by decision-makers. Studies on the applications of GIS repeatedly show that staff and organisational factors are more important than technology in successful applications of GIS.
[B]Data[/B]
The lack of available data remains one of the major hindrances in the use of GIS. As a type of information system, GIS needs graphic and textual data in order to function. There is no life in GIS without applications and there can be no application if there are no data. In short, data are vital to GIS. In the developed countries, a reasonable amount of geographical data is available thus making the establishment of a GIS relatively easy if sometimes expensive. Unfortunately, data are not so readily available in the developing countries. The most readily available data are those from remote sensing which means that they are restricted largely to land cover information from which a very limited amount of information about land use can be extracted.
[B]State-of-the-art of planning[/B]
The state-of-the-art in planning in the developing countries has not advanced much in comparison to GIS. The skills of planners and the planning systems may not be ready to utilise the data and functions provided by GIS. Planners could employ GIS in conjunction with new planning techniques so that they are better able to diagnose potential problems and assess the desirability of alternative plans. In spite of this, most planners in the developing countries are not yet aware of the benefits and potential applications of GIS. Furthermore, even though much effort has been spent on data collection, comparatively little has been spent on transforming data into information for making planning decisions.
[B]Staffing[/B]
With the rapid growth of GIS, there is a shortage of human resources even in the developed countries. This shortage is more severe in the developing countries both in absolute numbers and relative terms. There are very few people who know about GIS in developing countries. The shortage of skilled personnel is currently very severe, especially given the number of cities and regions in the developing countries that can benefit from GIS. The problem of training is very severe in the developing countries because of the lack of expertise and shortage of funds. In developing countries, GIS is often led by teaching and research in the universities.
[B]CONCLUSION[/B]
GIS are increasingly being used in planning agencies in the developed and developing countries. Many planning departments that have acquired mapping systems in the past have since shifted to GIS in lieu of mapping software. With the increase in user friendliness and the number of functions of GIS software, and the marked decrease in the prices of GIS hardware, GIS is now an operational and affordable information system for planning. It is increasingly becoming an important component in the planning support system. Recent advances in the integration of GIS with planning models, visualisation, and the Internet will make GIS more useful to urban planning. Today, the main constraints on the use of GIS in urban planning are not technical issues, but the availability of data, organisational change, and staffing.