Week 24 GEOG2750 – Earth Observation and GIS of the Physical Environment

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Outline:– Introduction– Principles and theory– Examples– Online SDSS

Lecture 20Spatial Decision Support

Systems (SDSS)

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Introduction• The ultimate application? OR... is this where the

previous 9 (or 19) lectures have been leading?• Use of GIS for environmental applications

includes:1. data management

2. characterisation and assessment

3. modelling and spatial analysis

4. management and decision support

• Applications 1 thru 3 culminate in 4... the end use?

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Application or decision support?

• An application may end at any point– CORINE, GRID, GEMS, etc. end at 1– descriptive/mapping exercise and EA may end at 2– predictive modelling exercise may end at 3– BUT they must all start at 1 and work through these

stages in sequence

• The ultimate end application must be decision making (i.e. management) and use in support of decisions made

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Aims of EnvSci

• Aims of environmental science:– to accumulate knowledge pertaining to the

environment?– to understand environmental processes and linkages?

• Objectives of environmental science:– gather data pertaining to environmental phenomena and

processes via empirical investigation?– to develop theories encompassing environmental

themes?– i.e. to gain understanding and insight through study

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Aims of EnvMan• Aims of environmental management:

– to prevent environmental deterioration and degradation?

– to promote sustainable use of the environment?– to prevent over use or exploitation of natural resources?– to preserve environmental diversity?

• Objectives of environmental management:– to control the environment and/or our influences upon

the environment via direct or indirect action?– i.e. putting environmental science to work!

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Decision making or support?

• Decision making vs decision support– GIS can provide certain tools for assisting in

the decision making process i.e.maps/displays as means of visualising the

problemoverlays as means of defining relationshipsmodelling as means of predicting outcomesetc

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…the answer

• GIS functions on their own are NOT decision making tools...– (i.e. they only ASSIST in the decision making

process)– ...therefore, GIS is not a decision making tool,

it is a decision SUPPORT tool

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Decision making

• Decision making:– a decision is a choice between alternatives to

meet specific objectives– the alternatives may represent:

different courses of actiondifferent hypothesesdifferent use of a geographical entityetc.

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Decision objectives• Objectives are governed by management goals and

in turn determine the range of alternatives– e.g. identify areas of high risk in soil erosion example

in order to address the goal of preventing soil erosion – resulting alternatives may be different maps

representing different management plans

• Process governing the way decisions between alternatives are made is the “decision rule”

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Conflict!

Making decisions to meet specific objectives often involves CONFLICT

Solving these conflicts is the art of good decision making

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Why GIS is not decision making

• GIS is not a decision making tool kit– to make (good) decisions requires:

knowledge & foresight insight & intelligence expertise, etc.

– i.e. rational choice between alternatives (especially where conflicts are present)

– GIS does not provide the above, BUT it can fulfil important role in decision making by providing decision support

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Decision support is…

• Decision support:– role of aiding the decision making process– simplest level:

expert advice regarding a decision between alternatives

– most complex level:dedicated computer systems i.e. decision support systems (DSS)

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Definition of a DSS• In general terms, DSS are:

– computer-based systems– dedicated to a restricted but well defined area of application– systems incorporating modelling and analysis with data and

database management systems– systems which do not make decisions, but facilitate

logistics of decision making process– interactive systems that help decision maker systematise

decision making process– providers of custom-built information– providers of user-friendly GUI with short response times

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Developing Spatial DSS

• The role of GIS?– GIS is an INCREDIBLY USEFUL tool– GIS toolbox can be used to develop SDSS– SDSS retain the general characteristics of basic DSS

but in addition they include: spatial data input capabilities storage of complex structures common in spatial data analytical techniques unique to spatial data cartographic output

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Basic SDSS structure

Database

G.I.S

Models

User Interface

User: expert knowledge

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GIS as SDSS?

• GIS fits nicely with additional requirements of a SDSS, but still does not meet the overall requirements of a DSS– GIS do not include expert knowledge – GIS do not possess artificial intelligence (AI)– GIS have only limited spatial analysis functionality– GIS are not very user friendly– GIS are not dedicated systems

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Question…

• How can we address these short-comings of GIS in developing SDSS?

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Example: nuclear waste disposal

• Example of a facilities location exercise involving multiple and conflicting criteria– ideal example application for a SDSS from initial site

survey through to public inquiry– problem has been approached by NIREX since 1981

and they are now on their fifth attempt four previous failures due to poor information, poor public

communication, obsession with engineering issues, etc. why didn't they listen to me?

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Nuclear waste… the problem

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Nuclear waste disposal… how?

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A GIS approach…• Basic GIS/MCE site search:

– identify screening (constraint) factors and their threshold criteria and use map overlay to identify areas satisfying above constraints

– identify multiple site-based factors on which to optimise– establish weighting scheme for factors– run MCE routine to identify optimal or near-optimal sites– run sensitivity analyses and identify final sites– pass the buck!

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Advantages…

• Advantages of such an approach are:– good at deterministic area screening– provides an application framework for

MCE– MCE provides GIS with spatial analysis

functionality– provides a rational and objective

approach

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Nuclear waste disposal… where?

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Role of SDSS

• SDSS may be used throughout the site selection decision making process as follows:– aiding initial decision making process– public information, consultation and

participation– decision support at public inquiry

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Online SDSS

• If public participation is goal then need to:– maximise access to data and tools– maximise scope for public participation

at all stages of planning processat all stages of decision process

• Utilise web-based GIS for SDSS

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Examples web-based SDSS

• Virtual Slaithwaite

• WOODS

• Nuclear waste siting

• Wilderness mapping

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Conclusions

• SDSS is utlimate end application of environmental GIS– development of GIS-based SDSS– online SDSS

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Practical

• Running online SDSS– Run the eMapScholar online GIS exercise– http://www.ccg.leeds.ac.uk/teaching/nuclearwaste/– You must:

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