Table of Contents:

GIS and Its Applications

Urban

Cities are systems of tremendous, ever-evolving complexities. Guiding a city development requires spatial information that’s robust, nuanced, and constantly updated, as well as the problem-solving skills to apply that information. Spatial data points the w'ay to improving quality of life and building sustainable communities, while GIS professionals use spatial thinking to transform that data into actionable insight and solutions. For urban planning, GIS is being used as an analytical and modeling tool, which is needed to design and map the city landscape. These tools can be applied to a wide array of problems, w'hich comprises addressing problems related to data base structures, simple and complex analytical models alike. Visualization, spatial analysis, and spatial modeling are the most frequently used GIS functions in plan making. 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.

TABLE 1.1

Important Operations of Spatial Analysis in GIS Environment

Operation

Description

Measurement, basic geoprocessing

• Location, distance, area; point in polygon; line on polygon overlay; polygon overlay; nearest neighbor search; buffering, merge, dissolve, clip, intersection, union etc.; spatial join; raster processing (classification, logical/airthmatic operations, aggregation); vector-raster conversion

Proximity and contiguity analysis

• Proximity and contiguity analyses are respectively simple methods of determining and indicating measures of distance between locations, or of showing a location’s degree of adjacency to neighboring locations.

Intervisibility

• Defines, from map evidence, whether or not it is possible to have a direct line of sight between any two points on the map. Thus a calculation is made, bearing in mind the existence of high ground as shown by contours, whether or not hills or other high ground would obscure the line of vision.

Network analysis

• Simple forms of network analysis are covered in shortest route and connectivity. More complex analyses are frequently carried out on network data by electrical and gas utilities, communications companies etc. These include the simulation of flows in complex networks, load balancing in electrical distribution, traffic analysis, and computation of pressure loss in gas pipes,

Trend surface analysis

• Method for establishing whether a generalized spatial surface exists, (i.e., one which may be obscured by a mass of detail in the real world). For instance, in any one country there may be an overall "wealth” surface which trends perhaps from east to west but which could well be obscured by numerous pockets of prosperity or poverty. From the marine viewpoint, it is quite likely that trend surfaces would exist with regard to the distribution of particular species (i.e., such that they would gradually decline outwards from a biologically optimum area but in an irregular, and thus perhaps obscured, way).

Location optimization

• Widely used as a GIS-based method which allows for the selection of optimum locations for the siting of any activity. This analysis is usually used by larger commercial companies when seeking, for instance, sites for new retailing outlets or for centralized distribution points. Similar analyses are also used by the forestry and agricultural sectors in seeking to optimize their operations, though here physical rather than economic criteria might be more important.

Digital terrain modeling

• Process whereby it is possible, using digitized height data, to build a 3D model of any desired area. These models are also be called 2.5D since they only show surface heights and not true volumetric data.

Complex correlation analysis

• The ability to compare maps representing different time periods, extracting differences or computing indices of change.

GIS Application in Urban Studies

FIGURE 1.1 GIS Application in Urban Studies.

Fig. 1.1 depicts application of GIS in urban studies. Using this information, planners can use overlay analysis, where GIS can help to review and analyze checks on regulatory compliance, review of environmental impact, preservation of historic sites, regional planning beyond the borders of a city or town, and mapping the delivery of utilities and planning for service interruptions. The applications of GIS in urban planning, especially in areas of spatial modeling, have improved manyfold in the past two decades. 3D printing, water main breaks, participatory GIS, toponymy, estimating run-off and sources of storm water pollution. Integrating urban development visions with GIS such as smart urban planning, smart utilities, smart transportation, and smart public works are some of the examples.

 
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