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1.1 Concept and definition of GIS
During its early stages in the 1960s, a Geographic Information System, or GIS, was merely a data processing software used in a small number of government agencies and universities only. These early developments were partly sparked by the need for resource and land management, partly also by the idea that mapping and map production could be made more efficient with the help of computer-based automation techniques. Today, GIS has become an important field of academic study. It has become part of the toolbox for many disciplines, not only academic or within societal management, but with the emerging smartphone technologies also an integrated part of most people’s information infrastructure. Searching for the whereabouts of objects and phenomena has become almost as available and common as searching for textual knowledge about the same.
According to Lo and Yeung (2002), defining GIS is a complex task. Where some people perceive it as a branch of information, others see it as a field of academic study by focusing on its cartographic and spatio-analytical abilities. According to Rhind (1989), GIS is a combination of hardware and software systems, designed to capture, analyze and display the spatially referenced data to solve real-world problems. The United States Geological Survey (USGS, 1997) defined GIS as computer-based technology which can assemble, store, manipulate and display location data with geographic coordinates. In summary, GIS is a computer-assisted system that can manage geographically referenced data and use them to solve spatial problems (Lo & Yeung, 2002).
1.2 Components of GIS
GIS engages several components in addition to those of data and technology, most importantly its applications, the people using it, and the people affected by its use. The ‘data’ handled in GIS often refer to geographic data records on the locations and characteristics of natural features or human activities that occur on or near Earth’s surface. Primarily, there are two types of data in GIS representing the recorded features, namely vector and raster. Vector data depict the real world by means of discrete points, lines and polygons. Raster data depict the real world by means of grids of cells with spectral or attribute values, similar to digital pictures (Lo & Yeung, 2002). More about vector and raster data in GIS is explained in Chapter 4: Generating data in GIS. The ‘technology’ component of GIS is comprised of hardware and software. The hardware includes equipment for acquisition, storage, analysis and display of geographic information; for most practical purposes, this corresponds to computers with peripheral devices such as scanners. On the software side, GIS was conventionally developed using a hybrid approach. In such an approach, the graphical data engine handled the graphical data and a commercial Data Base Management System (DBMS) took care of the associated descriptive data (details about DBMS are given in Chapter 7: Attribute tables). The connection between the graphical data engine and the DBMS was provided by the software vendor in the form of a proprietary interface. The ‘application’ components of GIS can be explained from the major areas of GIS application today, namely academic, business, government, industry and military. The ‘people’ component of a GIS is comprised of GIS users classified into three categories: viewers, general users and GIS specialists (Lo & Yeung, 2002). While ‘viewers’ browse a geographic database for referral information, ‘users’ use GIS for providing decision-making services. On the other hand, ‘GIS specialists’ contribute in terms of management and development of the software.
1.3 Role of GIS in geo-spatial analysis (in the context of planning and architecture)
Though the first GIS attempts were developed in the late 1960s, it was not immediately popular in academia due to the high cost of hardware and the limited capabilities of the software (Yeh, 1999). The earlier versions of GIS software focused on computer mapping with only a few analysis tools (integration of cartography with GIS is explained in Chapter 5). Installation of GIS software started to increase from the early 1980s when the costs of hardware, computer storage and peripherals started to fall and the performance of hardware and software improved (Yeh, 1999).
Advances in vector-based GIS with improved data structures and related algorithms have made GIS more affordable and workable (Worboys, 2004). Since GIS provides a platform for collecting and organizing spatial data along with analyzing and manipulating capabilities, it has been readily adopted by disciplines such as geography, geology and planning.
Since the 1980s, GIS has been installed at different levels in urban and regional government departments in developed countries, notably in Europe and North America. In developing countries, GIS started to gain popularity among urban planners in the 1990s (Yeh, 1999). Since then, planners have started to use various GIS tools for management, visualization and analytics of spatial data to provide solutions to planning-related problems (Levine & Landis, 1989; Marble & Amundson, 1988; Webster 1993,). The many benefits of using GIS in planning include:
- Improved mapping – better access to map data ultimately leads to improved map accuracy. It can help to better maintain and manage map data.
- It also makes data collection and manipulation at mass scale easy.
- GIS has a tool to perform spatial as well as semantic queries. Planners can perform combinations of such queries to obtain useful information, which in turn contributes to their systematic analytic thinking.
- Because of fast and extensive access to types of geographical information, planners can explore a wider range of ‘what if’ scenarios.
- GIS analysis techniques are now becoming routine in planning analysis as they improve the analysis process. For example, urban planners can use GIS models to forecast the extent and location of urban growth and to estimate the impacts of planned actions.
- Through GIS, better communication of plans and their impact on the public, and between planners and politicians, is possible.
Most countries base their planning on legislation, specifying responsibilities and organizing of, requirements for, and limits to, planning. Typically, planning operates at different levels, ranging from overview to detail, linked to the geographical scope of the plans as well as to the topics covered and the type of decisions administered by the plan. In Table 1.1, we have tried to explain the conceptual relationship between planning procedures, plan levels and the planner’s methods, and specifically suggest how GIS tools can be of use at each step. In our understanding GIS tools are applicable at all levels of spatial or land-use planning, although they probably fit better into the processes at an overview level, with less to contribute at the most detailed level, where perhaps Computer-Supported Construction, Design and Visualization (CAD) tools might have more to offer.
Table 1.1 GIS tool applicability for different tasks at different levels and procedure steps of planning processes | Urban planning, spatial planning, land use planning – a synoptic rationalistic framework | Examples of planning tasks supported by GIS |
| Problem description, problem identification, problem analysis | Where is development needed? How much will the population grow, and where can we expect insufficient housing, school capacity and water supply? Where do traffic accidents occur often? How much capacity do the sewage treatment plants need in the future? Where is access to public transit low? |
| Identification of goals | Mapping of stakeholders and interest. Mapping of goals with a spatial extent. Mapping of legislative preconditions and requirements. |
| Developing alternatives – finding concrete solutions | Suitability analysis: what areas are feasible for protection? For development? For housing, retail or manufacturing? What areas yield conflicts and are not at all suitable? |
| Assessing alternatives, identify and quantify impacts | Mapping impacts – loss of land, loss of natural resources and values, visual consequences, pollution and noise. Economic and social impacts. |
| Evaluation, comparison and decision-making | Overlay analysis, multiple criteria evaluation; which alternatives come closest to achieving the goals? |
The use of GIS in architectural research and practice has started late compared to in the planning discipline. GIS analysis has been incorporated into the design process of visionary projects like the planned city of Masdar in Abu Dhabi (Zeiger, 2010). The city is planned to be zero-carbon and zero-waste, as it is driven by solar and renewable energy. According to Monsur and Islam (2014), GIS has the potential to contribute to architectural research and practice, especially in the areas of urban design, community planning and the site-selection processes. The benefits of using GIS in architecture are:
- By using GIS, architects can strengthen their analytical capability by linking multiple phenomena, thus viewing them through a ‘spatial lens.’ For example, an architect can use GIS for combining information about layers of geology, soil type, infrastructure and demography when planning a structure or selecting a site (Moore, 2013). Also, site qualities such as views, daylight and shadow, can easily be calculated and become part of the site assessment.
- Architects use a variety of visualization tools, such as AutoCAD, Google Earth, Adobe Illustrator and Google Sketchup to create dynamic and complex models (Monsur & Islam, 2014). GIS can be used in conjunction with these software applications.
- GIS helps architects to make informed decisions. It enables architects to find ways to make a building more efficient or to establish the very need for a building to be constructed.
- GIS techniques can be adopted in the pre- and post-design phases of an architectural project. For example, GIS behavioral mapping can help to predict users’ preferences in the preparation of a designed environment. It can provide a basis which can guide/evaluate design decisions (Monsur & Islam, 2014).
When facilitating GIS courses in the fields of planning and architecture, we have observed that students/practitioners of architecture and planning often find it difficult to relate to GIS analysis. This practical guidebook will help them to take informed decisions.
1.4 History of GIS in an Indian context
In 1982, it was felt by the Government that India should adopt a comprehensive approach to the management of natural resources such as land, water, forests, mineral resources, oceans, etc. In considering this need, the National Natural Resource Management System (NNRMS) was established in 1984. Under the aegis of the NNRMS, five Regional Remote Sensing Service Centres were established and several state and university centers were supported. But the real boost occurred in Indian GIS after the successful launch of the Indian Remote Sensing (IRS) series of satellites, starting ...
