What is GIS?

GIS is then defined, and a range of issues and ideas associated with its use identified. Much of the material introduced in this chapter will be covered in more detail later in the book, and be covered in more detail later in the book, and pointers to the appropriate sections are provided.

1) Where are particular features found?

When skiers visit Happy Valley they need to know where all the visitor facilities are located. to help the Happy Valley GIS is used to produce maps of the ski area. In addition, visitors can ask direct questions about the location of facilities using ' touch screen' computerized information points located in shops and cafes throughout the ski resort. These information points provide skiers with a customized map showing them how to find the facilities they require.

2) What geographical patters exist?

Over the last two ski seasons there have been a number of accidents involving skiers. All these incidents have been located and entered to the GIS. The Happy Valley management team is trying to establish whether there is any spatial patters in the accidents. Do accidents of a certain type occur only on specific ski pistes, at certain points on a ski piste such as the lift stations, or at particular times of tday? So far one accident black spot has been identified where an advanced ski run cuts across a slope used by beginners, just below a mountain restaurant.

3) Where have changes occurred over a given time period?

In Happy Valley avalanches present a danger to those skiers who wish to venture off the groomed ski pistes. The management team and the ski patrol use the GIS to build up a picture of snow cover throughout the area. This is done by regularly recording snow depth, surface temperature, snow water content and show strength at a number

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of locations. A study of the geographical changes in these parameters helps the management team prepare avalanche forecasts for different locations in Happy Valley.

4) Where do certain conditions apply?

Every day, during the winter season, the happy Valley management team provides information on which ski pistes are open. Since this depends on the snow cover, avalanche danger and wind strength , data on these factors are regularly added to the GIS from reports provided by the ski patrols and local weather service. The warden can use the GIS to help identify which runs should be opened or closed.

5) What will the spatial implications be if an organization takes certain action?

The access road to Happy Valley is now too narrow for the number of skiers visiting the area. A plan is being prepared for widening the road. However, any road-widening scheme will have impacts on a local nature reserve as well as surround farm land. The Happy Valley GIS is being used to establish the amount of land that is likely to be affected under different road-widening schemes.

Searching for SITES:

Searching for optimum location to put something is a task performed by individuals and organization on a regular basis.

NIREX is the UK company with responsibility for the identification of suitable radioactive waste disposal sites.

In the past, NIREX used a pen and paper approach to sieve through large numbers of paper maps containing data about geology, land use, land ownership, protected areas, population and other relevant factors.

Openshaw et al. (1989) demonstrated the use of GIS for this application, and their method is summarized in Figure 1.1. First a number of data layers were established, each containing data for a

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separate siting criterion ( for example, geology, transport networks, nature conservation areas and population statistics).

Figure 1.1 Using GIS for siting a nirex waste site ( Adapted from Openshaw et al., 1989).

Evaluating Land use Planning:

Virtually every country in the world has areas of natural beauty and conservation value that are managed and protected in the public interest.

The protect area of Zdrske Vrchy, in the Bohemian – Moravian highlands of the Czech Republic, is an example of an area that has suffered as a result of ill-considered state control.

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Issues raised by the NIREX case study:

Errors in source data, such as those introduced during the conversion of data to digital form, may have a significant effect on the GIS site – searching process. Mistakes in capturing areas of appropriate geology form paper maps may lead to inappropriate waste repository sites being identified, because areas on the ground will have different geological properties from those recorded in the GIS.

The GIS site – searching process relies on the translation of abstract concepts such as 'near to' and ' far from' into precise conditions that can be mapped.

GIS output can be used to inform public participation in the decision – making process. A series of maps could be used to illustrate why a particular geographical location has been identified as a suitable site for the disposal of radioactive waste.

Specialists in hydrology, geology and ecology were consulted to identify a range of important criteria describing:

the type of soil and its waster retention ability;

the character of the topography ( for example, presence of absence of hollows or hills);

the type of land use, as certain agricultural practices exploit the water retention capacity of the landscape; and

the presence or absence of human-enhanced water drainage channels.

Paper maps ( for soil type and geology);

Contour map ( for topography);

Ecological field maps ( for drainage conditions); and

Remote sensing ( for land use ).

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The Zdarske Vrchy project shows how GIS can be used to bring together data from a wide variety of sources to help address a range of environmental management problems.

Issues raised by the Zdarske Vrchy case study.

The greatest problem associated with bringing data together for the creation of the Zdarske Vrchy GIS was deciding which map projection to adopt as the common frame of reference. Several different projection systems were used by the source maps. A projection system is the method of transformation of data about the surface of the earth on to a flat piece of paper. Because many methods exist which can be used to perform this task, maps drawn for different purposes ( and maybe even for the same purpose but at different points in time ) may use different projection systems. This does not present any problems as long as the maps are used independently. However, when the user wishes to overlay the data in the GIS the result can be confusing. Features that exist at the same location on the ground may appear to lie at different geographical positions when viewed on the computer screen .This problem became apparent in the Zdarske Vrchy project when the road network present on two of the maps, was compared. Map projections are explained in more detail in Chapter 2.

The Zdarske Vrchy case study also shows how GIS can be used to create model of environmental processes with maps used as the building blocks for the model. The topic of modeling and GIS is returned in Chapters 6 and 7.

Bringing people together to search for a solution to a common problem is often difficult. Different specialists will have diffeetn ideas about the problem. For example, an econlogist might recommend one approach, an engineer a second and an economist a third. The Zdarske Vrchy project whoed how, through the use of GIS, the common medium of the map could be used as a tool to help experts from different backgrounds exchange ideas and compare possible solutions. The idea that GIS can be used as a participatory problem solving tool

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has also received considerable attention for the GIS research community ( Carver et al., 1997) Chapter 7 consideres this topic in more detail.

Constraints excluded certain areas from the analysis altogether; for example, participants could decide that they did not wish to live with 500 m of a major road.

Locations of houses that were for sale were plotted over the top of the suitable areas identified , and ranked according to the number of criteria which they meet.

Figure 1.2 Using GIS for identifying conservation zones in Zdarske Vrchy ( Adapted from Petch et al., 1995)

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Figure 1.3 Using GIS to assist in house hunting.

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Table 1.1 Application areas for GIS

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The Department of the Environment (1987) lists the capabilities that a 'well – designed GIS ' should be able to provide:

1) Quick and easy access to large volumes of data.

2) The ability to:

o select detail by area or theme;

o link or merge one data set with another;

o analyze spatial characterizes of data;

o search for particular characterizes or features in an area;

o update data quickly and cheaply; and

o model data and assess alternatives.

3) Output capabilities ( maps, graphs, address lists and summary statistics ) tailored to meet particular needs.

Components of a GIS :

There are examples of software already developed to perform similar tasks, including Wigwam in the UK ( Anon., no date) and GeoData in the USA (ESRI, 1995) . These systems have been designed to make it possible for a home buyer to visit their estate agent, explain the type of house and neighborhood they prefer, and come aways with a map showing the locations of houses for sale which meet their requirements. These products bring help to the home buyer deciding where to look for a new home in an unfamiliar area.GIS in this context is a decision support system.

Defining GIS:

There have been so many attempts to define GIS that is difficult to select one definitive definition.

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Some of the shorter definitions give an idea of what a GIS is, albeit in a superficial way. Fuller definitions give more idea of what GIS can do, as well as what they are.

Computer Systems and Software:

GIS run on the whole spectrum of computer systems ranging from portable personal computers (PCs) to multi-user supercomputers, and are programmed in a wide variety of software languages. These include ( after Burrough, 1986):

the presence of a processor with sufficient power to run the software;

sufficient memory for the storage of large volumes of data;

a good quality, high – resolution colour graphics screen; and

data input and output devices ( for example, digitizers, scanners, keyboard, printers and plotters).

Spatial Data:

All GIS software has been designed to handle spatial data.

latitude and longitude as a geographical reference. This reference can be used to deduce relationships with nearby features of interest . If the latitude and longitude of a weather station are known, the relative position of other weather stations can be deduced, along with proximity to ski slopes and avalanche areas;

connection details such as which service roads, lifts and ski trails would allow the meteorologist access to the weather station;

non-spatial ( or attribute ) data, for instance details of the amount of snowfall, temperature, wind speed and direction.

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A series of spatial references to describe position;

Details of other runs that cross or join the ski piste;

Attribute data such as the number of skiers using the piste and its standard of difficulty.

Spatial data, represented as either layers or objects, must be simplified before they can be stored in the computer.

Area features are used to represent geographical zones, which may be observable in the real world ( such as the happy valley car park ) or may be artificial constructs ( such as administrative areas ).

Data management and Analysis Procedures:

The functions that a GIS should be able to perform include data input, storage, management, transformation, analysis and output.

It is the procedure of encoding data into a computer – readable form and writing the data to the GIS database.

Non-spatial attribute data describe what the features represent. They tell the computer what a particular set of entities represent.

Aronoff ( 1989) classifies GIS analysis procedures into three types:

1) Those used for storage and retrieval. For example, presentation capabilities may allow the display of a soil map of the area of interest.

2) Constrained queries that allow the user to look at patterns in their data. Using queries, only sandy soils could be selected for viewing or further analysis.

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3) Modelling procedures, or functions for the prediction of what data might be at different time and place. Predictions could be made about which soils would be highly vulnerable to erosion in high winds or during flooding; or the type of soil present in an unmapped area.

The form of data output used will depend on cost constraints, the audience to whom the results are directed, and the output facilities available.

However, most GIS output is in the form of maps. These may be displayed on – screen for immediate communication to individuals or small groups, photographed, stored digitally, or plotted to produce permanent hard copy.

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Figure 1.4 Points, line and areas.

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For an overview of GIS form a more applied perspective there are a range of texts available . Korte (1993) provides a ' smart managers' guide' to GIS that offers comment on industry trends and particular software systems. Martin (1996 ) looks at GIS with a focus on socio- economic applications in a UK setting; while Grimshaw (1994) considers GIS from an information namangement perspective and offers some useful business case studies.

Like many GIS texts, Martin (1996) , Burrough (1986) and Korte (1993) contain useful glossaries of commonly used GIS terms and acronyms.

People and GIS

Most definitions of GIS focus on the hardware, software, data and analysis components.

GIS projects range from small research applications where one user is responsible for design and implementation and output, to international corporate distributed systems, where teams of staff interact with the GIS in many different ways.

Research has been undertaken to highlight the factors that promote successful GIS and it has been suggested that in certain business sectors, innovative flexible organization with adequate resources and straightforward applications are more likely to succeed ( Campbell and Masser, 1995).

So the issues surrounding how to choose a system and how implement it successfully require examination.

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Conclusions:

GIS technology is now well – established and as we will see in chapter 9, has bee in use since the 1960s.

The growth in application areas and products through the later years of the twentieth century ha helped GIS to become an accepted tool for the management and analysis of spatial data.

Further Study:

There are many sources of further reading that complement the material presented in this chapter.

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