Copyright 2010, The World Bank Group. All Rights Reserved. Basic principles Part 1 Geographic Information Systems Produced in Collaboration between World

Copyright 2010, The World Bank Group. All Rights Reserved.

Basic principles

Part 1

Geographic Information Systems

Produced in Collaboration between World Bank Institute and the Development Data Group (DECDG)


Module Objectives

Modules designed for non-GIS practitioners and Managers

National Statistics Organizations or working in Agriculture or Health

Geographic Information Systems, its principles, components, uses and successful implementation imperatives

Non-technical reference – does not detail high level technical issues

Focus on providing non-technical individuals with:Base knowledge to understand the core principles of -

Geographic Information Systems (GIS)The Global Positioning System (GPS)Remote SensingIntegration and Implementation Issues


The History of GIS - Introduction

To understand GIS one needs to understand its history

The history of GIS spans four decades

It springs from many origins and mingles many disciplines

GIS is many things to many people

Evolved fromMainframe computers toMini computers toPersonal computers toDistributed computing and Visualisation tools operating via the Internet

Has gained increasing general awareness and acceptance


The History of GIS - Introduction

The awareness of the importance of and need for spatial information increased

The integration of mathematical and statistical models with modern computing aand mapping techniques initially drove GIS

The prominence of spatial information is a direct result of the computer and information age

The history of GIS can be divided into four phases: (adapted from Berry)Computerized Mapping: The early yearsSpatial Data Management – The idealistic teenagerMap Analysis and Modeling – The maturity of GISMultimedia Mapping and Visualization – The rise of Neogeography


The History of GIS – Computerized Mapping

Mid 1960s to 1970s

The focus was on the automation of map creation and map theme overlays

Development limited to expensive and cumbersome computer mainframe systems – universities and government departments

Development was driven mostly by individuals with little collective effort

Pioneering work was done which established many of the underlying modern GIS concepts and procedures


The History of GIS – Spatial Data Management

The 1980s

Exploitation of the change in data formats and computer environment

The development of spatial data management systems was pioneered

Enabling spatial information to be queried using traditional database methods

Focus on data availability, accuracy and standards – market growth for digital map products and vendor software

Linking data about a feature from a database to a map


The History of GIS – Map Analysis and Modeling

The 1990s

Realisation that information is a key driver for development

From where is what?...to spatial interrelationships and WHY?

Comprehensive theory of map analysis – spatial statistics and spatial analysis – applying traditional statistical and mathematical operations from different subject matter fields to GIS

Analysing statistical data within the spatial component

Allowed the GIS community to create new operations unique to GIS – Optimal path routingVisual exposure density Intelligent thematic mappingGeodemographic neighbourhood and trade area analysis


The History of GIS – Multimedia mapping and Visualization

The Naughties

A broad adoption of geotechnology in our everyday lives – Geography now matters to everyone

Geotechnology is one of the three major mega technologies of the 21st centuryComplex vendor based GIS giving way to web services and customised application solutions

Web based spatial visualization tools and the integration of GPS and remotely sensed imagery allows non-geographically inclined persons to create customised maps and views

The age of the neogeographer has arrived - someone who uses geotechnology for personal or even business use but does not have a background in geography – GIS has come full circle


Defining GIS

Traditional definition: A collection of hardware and software to – CreateStoreAnalyseDisseminate spatial data and its related attribute information

Operates on many levels of increasing complexity

Common database operations and statistical analysis is integrated with visualisation benefits of digital maps

Every object present on the Earth can be georeferenced and its related attribute information can be linked through a database


The acronym, G I S

The constant evolution of GIS means the acronym is also evolving

G I – refers to Geographic or Geospatial information

3 Distinct technologies comprising Geographic Information Technology:Global Positioning Systems (GPS)Remote Sensing Imagery (RS)Geographic Information Systems (GIS)

S – can mean any of the following:Systems – the technology for the acquisition and management of spatial informationScience – comprehending the underlying conceptual issues of representing data and processes in space-timethe theory and concepts behind the technologyStudies – understanding the social, legal and ethical issues associated with the application of GIS


Briggs’s Revised Definition of GIS

Considering the information on the previous slide, the following revised definition of GIS has been suggested

A system of integrated computer-based tools for end-to-end processing(Capture)(Storage)(Retrieval)(Analysis)(Display)

of data using location on the earth’s surface for interrelation in support of operations management, decision making, and science.

This system - Includes a set of integrated tools for spatial analysis

Encompasses end-to-end processing of dataUses explicit location on earth’s surface to relate data Is aimed at decision support, as well as on-going operations and scientific inquiry


The Philosophy of GIS

Why the phenomenon of GIS?

GIS constantly tries to progress from:Data (facts)To information (facts within context)To knowledge (interrelationships among relevant facts)To wisdom (understanding and actionable knowledge)

The key driver in GIS evolution is to gain wisdom and understanding – to make accurate decisions using relevant knowledge

Computerised map feature layers = data (spatial facts) – distillation of data to information is left to intuitive assessment, human interpretation and biased judgement

Mature GIS – new set of database query, mathematical and statistical analysis methods – allow us to further distil spatial facts to information and knowledge – ultimately, wisdom and understanding


GIS – The Answer Machine

All GIS analysis begins with asking a question relevant to the real world –

We collect/create/add spatial and attribute information Apply database queries, spatial and statistical analysis methodsApply our own specialised knowledge about the relevant subject matter

We arrive at an answer/conclusion/understanding

The accuracy of the answer dependent on the accuracy, currency, relevancy of the data used and the statistical and spatial analysis methods – Most important – how accurately we apply our own knowledge to interpret results


So what are these questions?

There are 7 basic questions we can ask a GIS (consider the table adapted from Berry)

First three questions inventory based – deal mainly with data only

The Question Function Approach

Can you map that? Mapping Descriptive

Where is what? Management Descriptive

Where has it changed? Temporal Descriptive

What relationships exist?

Spatial Prescriptive

Where is best? Suitability Prescriptive

What effects what? System Prescriptive

What if….? Simulation Prescriptive

Latter four questions are analysis related – deal with the creation of new information, knowledge and ultimately, understanding


Question 1 – Can you map that?

The first question ever asked in GIS – Computerized mapping

A large portion of GIS still deals with this question – updating and timely output of map products

Digital map creation much more productive, accurate than manual draughting with many more aesthetic possibilities

Typical question in a Population Census environment would be: “Can we map our new Enumerator Area (EA) boundaries digitally and can we add prominent landmarks as points within each EA polygon?

Transferring analogueEA boundaries to digital format throughheads-up digitizing


Question 2 – Where is what?

Exploits the linkage between the digital map and database management technology

Conditions surrounding the first two questions determines the character and design of GIS – remaining questions determine the sophistication of its applications

Relevant question - Where are the Enumerator Areas with a male population of more than 200?


Question 3 – Where has it changed?

Temporal analysis or change over time – transition from descriptive to prescriptive queriesAffords a new perspective on existing data

Typical question – “Assess the prevalence of pit latrines within a peri urban environment over a period of five years.”

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Labels of EA_AREA

MAP_SHEET

NP_EA

EA_AREA

SOCIAL_BOUNDARIES

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Using imagery from different years to determine urban development and densification for EA

demarcation


Question 4 – What relationships exist?Focuses on spatial and statistical analysis across data layers

Here we deal with derived information from existing data

Requires developed spatial reasoning in order to ask the correct questions

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Female Literacy RatePercent

10 20 30 40 50

Female Literacy Rate (percent)

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40

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ContraceptivePrevalence

Rate

Finding a relationship between female literacy and contraceptive use


Question 5 – Where is best?

Suitability models, trade area analysis and site selection

Spatial reasoning and subject matter knowledge is important

Clinic site selection using buffer analysis


Question 6 – What effects what?

Involves system models – tracking of cause and effect through empirically derived relationshipsOutcome based models built with the sole purpose to identify causality or trends within real world environments


Question 6 – What effects what?

From InnovativeGIS:

Creating a customer density map


Question 7 – What if?....scenarios Models and predicts outcomes of real world actions and occurrences which already happened or might still happen.

What if – we implement this there or move this here or build this there – what will the outcome or forecast be?

What if we increase the floor space of this shopping centre by

20000 sq/m – How would it impact trade area?

Documents

Copyright 2010, The World Bank Group. All Rights Reserved. Basic principles Part 1 Geographic Information Systems Produced in Collaboration between World