GIS concepts

Basic Spatial Perspective

and GIS Concepts

COMPUTERISED CARTOGRAPHY-- performing cartographic functions by means computer hardware and software

CARTOGRAPHY -- art and science of map making

A map represents geographic features or other spatial phenomena by graphically conveying information aboutlocations and attributes

MAP

•Map(graphic) information * only graphic data is available and retrieval * networks are not defined.•Map publication * spatial relationship not defined

Computer Assisted Mapping

INTRODUCTION

IntroductionIntroduction

Graphics are Graphics are internationalinternational::AusgangAusgang

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Salida...Salida...

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Why Use GraphicsWhy Use Graphics

Graphics are Graphics are holistic:holistic:““a picture says more than a thousand words...”a picture says more than a thousand words...”

““First road left, then First road left, then cross the railroad cross the railroad and continue until and continue until you cross the river, you cross the river, then the first right then the first right and right again on and right again on the crossroads...”the crossroads...”

IntroductionIntroduction

Why Use GraphicsWhy Use Graphics

What is a GIS?What is a GIS?A GIS is a database management system A GIS is a database management system

forforspatially distributed features and the spatially distributed features and the associated attributes.associated attributes. Spatial data captureSpatial data capture ManagementManagement AnalysisAnalysis DisplayDisplay Decision makingDecision making ResearchResearch

WHAT IS A GIS ?WHAT IS A GIS ?GEOGRAPHICGEOGRAPHIC implies that locations of the data items are implies that locations of the data items are

known, or can be calculated, in terms of Geographic known, or can be calculated, in terms of Geographic coordinates (Latitude, Longitudecoordinates (Latitude, Longitude))

INFORMATIONINFORMATION implies that the data in a GIS are implies that the data in a GIS are organized to yield useful knowledge, often as coloured organized to yield useful knowledge, often as coloured maps and images, but also as statistical graphics, tables, maps and images, but also as statistical graphics, tables, and various on-screen responses to interactive queriesand various on-screen responses to interactive queries..

SYSTEMSYSTEM implies that a GIS is made up from several inter-implies that a GIS is made up from several inter-related and linked components with different functions. related and linked components with different functions. Thus, GIS have functional capabilities for data capture, Thus, GIS have functional capabilities for data capture, input, manipulation, transformation, visualization, input, manipulation, transformation, visualization, combinations, query, analysis, modelling and output.combinations, query, analysis, modelling and output.

Some DefinitionsSome Definitions

An information system that is designed to work with data referenced by spatial or geographic coordinates. In other words, a GIS is both a system with specific capabilities for spatially-referenced data, as well as a set of operations for working [analysis] with the data. - Star and Estes, 1990 A working GIS integrates five key components: hardware,software, data, people, and methods. - ESRI, 1997

Automated systems for the capture, storage, retrieval, analysis, and display of spatial data. - Clarke, 1990 A system for capturing, storing, checking, integrating, manipulating, analyzing and displaying data which are spatially referenced to the Earth. - Chorley, 1987



A system of hardware, software, and procedures designed to support the capture, management, manipulation, analysis, modeling and display of spatially-referenced data for solving complex planning and management problems. - NCGIA lecture by David Cowen, 1989

An integrated package for the input, storage, analysis, and output of spatial information... analysis being the most significant. - Gaile and Willmott, 1989

GIS are simultaneously the telescope, the microscope, the computer, and the Xerox machine of regional analysis and synthesis of spatial data. - Abler, 1988

Components of GISComponents of GIS

A working GIS systemA working GIS system

integrates these five key components:integrates these five key components:

HardwareHardware SoftwareSoftware DataData PeoplePeople MethodsMethods

BASIC FUNCTIONS OF GISBASIC FUNCTIONS OF GIS

WHAT IS IT….?WHAT IS IT….?(LOCATIONS)(LOCATIONS)

Koramangala AREAKoramangala AREA

(X,Y)

WHERE IS IT ….?WHERE IS IT ….?(CONDITIONS)(CONDITIONS)

WITHIN THE WITHIN THE BangaloreBLOCK BangaloreBLOCK

HOW HAS IT HOW HAS IT CHANGED …?CHANGED …?(TRENDS)(TRENDS)

IMPROVEMENT INIMPROVEMENT INGROWTHGROWTHIN FIVE YEARSIN FIVE YEARS

WHICH DATA AREWHICH DATA ARERELATED ….?RELATED ….?(PATTERNS)(PATTERNS)

NEARESTNEARESTAdogodi areaAdogodi area

WHAT IF….?WHAT IF….?(MODELS)(MODELS)

FINDING SOLUTIONS TO FINDING SOLUTIONS TO THE FORTH QUESTIONSTHE FORTH QUESTIONS

What Data is in Your What Data is in Your GIS?GIS?

What What featuresfeatures do you map? do you map? What What attributesattributes do you need to do you need to

collect data on?collect data on? What What attribute valuesattribute values can you give can you give

the attribute?the attribute?

TOPOLOGIC DATA ELEMENTS

Node

Line (Arc)

Area(polygon)

Nodes: defines beginning and end of the lineLine: defines roads,utilities,boundaries,etc.,Areas: administrative boundaries, forest block,JFM areas,lakes

Supports spatial analysis

Supports network analysis

Supports map publication

Point FeaturesPoint Features

Spatially distributed entities, activities Spatially distributed entities, activities oror

eventsevents Points have a single geographic Points have a single geographic

coordinate such as:coordinate such as: TreeTree Traffic accidentTraffic accident Lamp postLamp post

Line FeaturesLine Features


eventsevents Lines (Arcs) are a series of Lines (Arcs) are a series of

geographic coordinates joined to form geographic coordinates joined to form a line such as:a line such as: RoadRoad Stream Stream RailwayRailway

Area FeaturesArea Features


eventsevents Areas (Polygons) are a series of Areas (Polygons) are a series of

geographic coordinates joined geographic coordinates joined together to form a boundary such as: together to form a boundary such as: LakeLake Soil typesSoil types

SPATIAL SPATIAL DATADATA

Raster

Vector

DATA MODEL AND STRUCTUREDATA MODEL AND STRUCTURE

RASTER MODELRASTER MODEL VECTOR MODELVECTOR MODEL

Spatial data structuresSpatial data structures

Raster data files consists of Raster data files consists of rows of uniform cells coded rows of uniform cells coded according to data vaccording to data values- Land alues- Land cover classes is a fine example.cover classes is a fine example.

Spatial data structuresSpatial data structures

Vector data files has been Vector data files has been captures as points, lines and captures as points, lines and polygonspolygons- Land cover classes is - Land cover classes is a fine example.a fine example.

ADVANTAGES OF VECTOR MODELADVANTAGES OF VECTOR MODEL

• PRECISE EXPRESSIONPRECISE EXPRESSION• LESS DATA VOLUMELESS DATA VOLUME• FULL TOPOLOGYFULL TOPOLOGY• FAST RETRIEVALFAST RETRIEVAL• FAST CONVERSIONFAST CONVERSION

ADVANTAGES OF RASTER MODELADVANTAGES OF RASTER MODEL

• SIMPLE DATA STRUCTURESIMPLE DATA STRUCTURE• EASY FOR OVERLAY AND EASY FOR OVERLAY AND MODELLINGMODELLING• SUITABLE FOR 3D DISPLAYSUITABLE FOR 3D DISPLAY• INTEGRATION OF IMAGE DATAINTEGRATION OF IMAGE DATA• AUTOMATED DATA CAPTUREAUTOMATED DATA CAPTURE

DISADVANTAGES OF VECTOR MODELDISADVANTAGES OF VECTOR MODEL

• COMPLICATED STRUCTURECOMPLICATED STRUCTURE• DIFFICULTY IN OVERLAYDIFFICULTY IN OVERLAY• DIFFICULTY IN UPDATINGDIFFICULTY IN UPDATING• EXPENSIVE DATA CAPTUREEXPENSIVE DATA CAPTURE

DISADVANTAGES OF RASTER MODELDISADVANTAGES OF RASTER MODEL

• LARGE DATA VOLUMELARGE DATA VOLUME• LOW PRECISIONLOW PRECISION• DIFFICULTY IN NETWORK DIFFICULTY IN NETWORK ANAYLYSISANAYLYSIS• SLOW CONVERSIONSLOW CONVERSION

AttributesAttributes can be numeric or alfa can be numeric or alfa numeric data that is assigned to numeric data that is assigned to a point, line or area spatial a point, line or area spatial featuresfeatures

Example Attributes…Example Attributes…

Stand ID, Compartment Stand ID, Compartment no,Vegetation type, Name of the no,Vegetation type, Name of the Forest Block,Type of Road,VSS Forest Block,Type of Road,VSS code etc.,code etc.,

AttributesAttributes

Data Capture SourcesData Capture Sources Digitizing from paper mapsDigitizing from paper maps ScanningScanning Traditional surveying techniquesTraditional surveying techniques Paper records & field notesPaper records & field notes PhotogrammetryPhotogrammetry Remote sensingRemote sensing GPSGPS

GIS Data StorageGIS Data Storage

There are two main types of data in a There are two main types of data in a GISGIS

databasedatabase CartographicCartographic - observations on - observations on

spatially distributed features, activities, spatially distributed features, activities, or events, which are definable as:or events, which are definable as: PointsPoints Lines (Arcs)Lines (Arcs) Areas (Polygons)Areas (Polygons)

GIS Data StorageGIS Data Storage

Non-Cartographic Non-Cartographic - descriptive - descriptive information in a database about information in a database about the cartographic features located the cartographic features located on a map.on a map. AttributesAttributes Attribute ValuesAttribute Values

AttributesAttributes

Description or characteristic of a Description or characteristic of a featurefeature

Possible attributes for the feature Possible attributes for the feature TreeTree HeightHeight DiameterDiameter SpeciesSpecies ConditionCondition AgeAge

Attribute ValuesAttribute Values

The value given to an attributeThe value given to an attribute Possible Possible valuesvalues for the attributes of for the attributes of

a Tree featurea Tree feature HeightHeight = 15m= 15m DiameterDiameter = 0.75m= 0.75m SpeciesSpecies = Oak= Oak ConditionCondition = Good= Good AgeAge = 8 years= 8 years

Types of Attribute ValuesTypes of Attribute ValuesThere are a number of different There are a number of different

types oftypes ofattribute valuesattribute values Feature Attribute Attribute Values

Character Pole Pole ID ABC123

Numeric Pole Height 15m

Menu Pole Condition GoodAveragePoor

Date Pole Date User generatedAuto generated

Time Pole Time User generatedAuto generated

BASIC FUNCTIONS OF GISBASIC FUNCTIONS OF GIS

• DATA AQUISITION AND DATA AQUISITION AND PREPROCESSINGPREPROCESSING

DIGITIZINGDIGITIZING EDITINGEDITING

TOPOLOGY BUILDINGTOPOLOGY BUILDING

PROJECTIONPROJECTION ATTRIBUTIONATTRIBUTION

WHY GIS ?WHY GIS ?

To inventory and monitor resourcesTo inventory and monitor resources To test the sensitivity of our analysis To test the sensitivity of our analysis

assumptionsassumptions To simulate potential impacts of To simulate potential impacts of

management alternativesmanagement alternatives To make the map the 2nd time, the To make the map the 2nd time, the

50th time, the 100th time...50th time, the 100th time...

Uses of a GISUses of a GIS

Mapping geographical Mapping geographical characteristics for analysischaracteristics for analysis

Modeling alternative processes Modeling alternative processes for management plansfor management plans

Managing a utility’s assetsManaging a utility’s assets Monitoring changes in Monitoring changes in

environmental factorsenvironmental factors

ADVANTAGES OF GIS IN SIMPLE ADVANTAGES OF GIS IN SIMPLE TERMSTERMS

Though collection of data is difficult once it is Though collection of data is difficult once it is collected, it can be stored safely in digital form collected, it can be stored safely in digital form (in computer) forever without damage, which (in computer) forever without damage, which usually happens to our maps.usually happens to our maps.

Once if a map is prepared accurately it can be Once if a map is prepared accurately it can be printed in any scale without any redrawing.printed in any scale without any redrawing.

Large scale maps at smaller units (Beats) level Large scale maps at smaller units (Beats) level can be joined for creating maps at divisions or can be joined for creating maps at divisions or district level, very accurately within few minutes.district level, very accurately within few minutes.

Contd..Contd..

Changes can be incorporated very easily Changes can be incorporated very easily in computer and it doesn’t require any in computer and it doesn’t require any redrawing.redrawing.

Same map can be generated even after Same map can be generated even after 100s of years later.100s of years later.

New things can be known after overlay New things can be known after overlay of different themes and a new types of of different themes and a new types of maps can be generated.maps can be generated.

Work can be done faster than manually.Work can be done faster than manually.

The work of decision makers and end The work of decision makers and end users will become easier.users will become easier.

ADVANTAGES OF GIS IN SIMPLE ADVANTAGES OF GIS IN SIMPLE TERMSTERMS

OriginOrigin

The Cave Paintings

1351The Medici sea atlas is published that contains a ‘world’ map.

1375 The Catalan atlas is prepared by Catalan cartographers who made great contribution in the completion of reformation of world map.

1477The first printed edition of the ‘Geography’, Bologna is published on the basis of manuscript atlases, produced by Dominus Nicholaus Germanus

Cave Paintings are considered to be the first GIS Maps as some unknown information (attributes) is linked to it.

A. Cave Paintings have graphic information regarding the animals and their tracks of migration.

B. These paintings used to get shared with in the tribe groups through generations.

C. Most of the ancient civilizations are found by its Cave Paintings.

1.Mesapotomia

2.Central Asia

Manual MappingManual Mapping

Manual MappingDr.John Snow in 1854 used London City Map to Depict

Cholera effected areas.

•Dr.John snow has used a manual Map to track the cholera effected area of the central London, which has been ultimately resulted in finding a contaminated well. This is considered as the first GIS analysis in the world.

•Europeans produced first Manual Maps to travel over seas.(Vascodigama,Columbus).

• In American Rervolution Maps are used with huge Overlays to track the Troop Movements.

Manual Mapping is an art of showing the real time objects on a piece of paper with a uniq concept located in it.(geography,History,social changes)

Manual Mapping-Computerized Manual Mapping-Computerized MappingMapping

• The Art of Manual mapping has been carried out till late 1950, where the computer based Mapping or drafting was introduced.

•In 1960’s THE Canadian Geographic Information Systems was found by Canada, which was leaded in providing the information on Natural resources and habitat.

•SkyMap is the world’s first Drafting package.

•The Harvard school for GIS (Center for Geographic analysis) was reopened in 1960 and all the major GIS vendors today are from this institute. (ESRI,Intergraph etc).

• The legendry art of Manual mapping helped the mankind to produce the modern world.

CAD (Computer Aided Drafting)CAD (Computer Aided Drafting)

CAD is rooted in drafting—CAD has a great facility for creating and representing geographic features as drawings in a computer

In early graphics systems, the data model was simple and consisted almost entirely of symbolized graphic features

Advantages:• Features were represented by a graphic symbol• Features were stored in a single file format.•Tracking of the data was much easier.

In graphic system software, map files (i.e., layers) can be edited, manipulated, displayed, & generally managed..

Disadvantages:• Features were not so intelligent as today.• The time taken to regenerate the drawing is very high.• Performance of the system is very poor due to graphic size.• Editing of the existing drawing/Map is is very hectic as if one feature is effected in one area then all the feature with the same symbol need to be changed again.

AM/FM a Semi GISAM/FM a Semi GIS

After 1970’s CAD have been implemented in many sectors and was very successful.

However, Large Utility companies and other companies which needed Facility Mapping suffered with the inabilities of CAD systems.

The Concept of facility Mapping has been into the lime lite around mid 70’s.

FM is nothing but CAD but it has its own defined features in it (transformers, repeaters) along with the default text. Some advanced FM systems even provided a data linking facility to the features.

In one word an AM/FM systems is 90% Automated CAD systems with its defined features.

Later on FM has become the stepping stone for GIS

1988 - Indian Remote Sensing Satellite (IRS) system is commissioned with the launch of IRS-1A.

1989 - The National Remote Sensing Agency prepares the first Wasteland Atlas.

1989 - The National Remote Sensing Agency prepares the first Wasteland Atlas.

1996 -ESRI India is formed.

- Tata Consultancy Services (TCS), India established in 1968, starts with the TCS GIS group to provide services in the areas of GIS, Digital Image Processing, Automated Mapping and Facility Management.

-The Mountain Natural Resource Information Systems (MENRIS),Nepal is established to facilitate the application of GIS and remote sensing ( contd…)

Mile Stones in GIS

1998 - Tata Infotech is appointed as exclusive distributor of MapInfo products in SAARC region.

- Bentley India is established.

- Kampsax India Ltd. a photogrammetry is formed.

- Tele Atlas starts its operation in India.

1999

-The first "GIS Forum South Asia’99" is organised at Nepal.

- Autodesk India Ltd. is formed.

- Landsat 7 carrying Enhanced Thematic Mapper Plus (ETM+) is launched. - IKONOS is launched

Mile Stones in GIS

Trends Trends

Era of Manual Mapping

AMFM\GIS

Desktop GIS

Application GIS

CAD\CAM

Web GIS Mobile GIS

MapObjects

MapX

GeoPbjects

Internet GIS

ArcIMS

MapXtreame

WebMap

MapGuide

Handheld GIS

ArcPAd

MapInfo

SuperGIS

Server Based GIS

Implementing GIS in various Implementing GIS in various DomainsDomains

UtilitiesUtilities Transport & logisticsTransport & logistics CommunicationCommunication Urban planningUrban planning MilitaryMilitary ForestryForestry EnvironmentEnvironment AgricultureAgriculture

List Of some important DomainsList Of some important Domains

Thank You

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GIS concepts