GIS technology is used to analyze the urban growth and its direction of expansion, and to find suitable sites for further urban development. In order to identify the sites suitable for the urban growth, certain factors have to consider which is: land should have proper accessibility, land should be more or less flat, land should be vacant or having low usage value presently and it should have good supply of water. GIS has been used in several industries and its applications cut across a variety of professions. We take a deep look at some of its applications in the field of urban planning and the role it plays in this field.
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. In particular, stereoscopic pairs of digital aerial photographs can be used to derive 3-dimensional CAD models of buildings for dynamic visualization of a city, or for direct import into a GIS database.
Analysis of existing situations
GIS can help to store, manipulate, and analyze physical, social, and economic data of a city. Planners can then use the spatial query and mapping functions of GIS to analyze 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. This data and analysis can then be used to inform important decisions that affect the current and future planning of an area.
Modeling and projection
A key function of planning is the projection of future population and economic growth. GIS can be used for prediction and projection. Spatial modeling 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, modeling 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.
Development of planning options
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 optimization models with GIS can help to formulate and develop planning options which try to maximize or minimize some objective functions. The simulation of different scenarios of development with GIS can help in developing planning options.
Selection of planning options
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. The use of GIS with multi-criteria decision analysis can provide the technical inputs in the selection of planning options. The data provided by GIS and the subsequent analysis done can be used to inform the decisions of the political class to ensure that the planning is designed and implemented the right way at the very first instance.
GIS can be used in the implementation of urban plans by carrying out environmental impact assessment of proposed projects to evaluate and minimize the impact of development on the environment. Following such work, remedial measures can be recommended to alleviate the impacts. Environmental impact assessments are usually a detailed process that require accurate estimations of data and impact analyses and GIS will come in handy in ensuring the same is achieved.