Brief Introduction to GIS

Concept, History and Data formats ByM Numan Kashif

Assistant Director Research

GIS

GIS is a system of computer hardware, software, data and the personnel to help store, retrieve, manipulate, analyze and present information that is referenced to a spatial location.

Spatial Location – a geographical location Information – visualization of analysis of data System – linking software, hardware, data Personnel – a GIS operator who is key to the power of GIS

GIS

A geographic information system (GIS), is a system that captures, stores, analyzes, manages and presents data with reference to geographic location data.GIS is the merging of

Cartography Interactive visualization Spatial Analysis Non spatial Analysis Database technology

GIS

GIS objectively deals with following aspects of Projects under going with any Domain.

Management Monitoring Cost Analysis. Production Analysis Decision making

Components of GIS

Several components are involved in GIS technology.

Work Flow

Process

Information+LocationAnalysis, PlanningAlternates

Decisions, Maps, Visualization, Predictions

Data+LocationGeo Data

GIS (Planning) Data Type and mode Criteria Application

Process Research Oriented

Information Output Understandability

Geographic Data Visualization Cartography

Geomatics Process Data Acquisition Scale, Instrumental or Non Instrumental, Standards and Units, Spatial and non

Spatial

Data Preparation Data Formats, Conversion, Digitizing, Image Processing, Classification

Data Management and Analysis Storage Mode, Updating, Deletion, Application Oriented Analysis, Data bases,

User Interfaces

Output and Decision Making Cartography, Traditional Rules, Manual, Digital, Visualization

GIS data Collection Planning Data Collection parameter. Non Spatial Data Types, Fields and attributes selection. Spatial Co ordinates, Geom, Projection and Transformation Data Collection Mode Decisions. Primary, Secondary

GIS data Collection Activity GIS Data Collection Time line.

Mata data entry for each theme or entity.

Precise and Accurate data collection according to requirements of Application and Planning is necessary for reliable outputs.

Quality data prepared gives Real World results and reliable outputs.

A single error can be input of many procedures and have significant negative impact or all Models

GIS Data Error Sources

Data Collection errors Sources. Human Error Spatial Errors Non Spatial Errors Topological Errors Conceptual Errors System Error (Format Conversion, Read

Error, Generalization)

GIS Data Manipulation

Conversion of Field or collected data in to Computer or digital formats.

Digitizing. Georeferencing. Add data from spread sheets or excel files. Add directly from GPS and connectivity with

Non spatial data (Attribute Joining). Layers making for different themes.

Data Query, Process and Analysis Overlay analysis. Buffer Analysis. Selection and spatial Selection analysis. Statistical Analysis. Join and Relates. Conversion and Transformation. Classification

Work Flow Review

Process

Information+LocationAnalysis, PlanningAlternates

Decisions, Maps, Visualization, Predictions

Data+LocationGeo Data

Output Generation

Results of analysis are suggested to be a Map or published reports.

Either a static map or a Digital map.

Ground Truthing

Outputs gives a key for monitoring, management and Planning for end users or Decision Makers.

History of GIS

Man is interested in knowing his surrounding more and exploring what is his own world is.

Mostly for the aspects of Defense, Safety, Attack, Shelter and food, mapping and knowing the resources around tribes gave, the mapping techniques, birth.

Formats were rough and different but the objectives were same.

We can get the proper samples of GIS for nearly 10000BC

Wall drawing of Catal Hyük, in Anatolia, Turkey,showing a city plan and erupting volcano

visible from the city, (ca. 6200 B.C.)Images courtesy of

HenryDavis.com

Babylonian Clay Tablet map (and reconstructed drawing)

from Ga-Sur, northern Iraq (ca. 2500 B.C.)

Images courtesy of HenryDavis.com

“Turin Papyrus” map by Amennakht, royal scribe, showing a portion of Wadi Hammamat in eastern Egypt,

prepared for one of King Ramesses IV’s quarrying expeditions(ca. 1150 B.C.) - Egyptian

Images courtesy of James A. Harrell, University of Toledo

Comparison between Turin Papyrus (left)

and modern topographic and

geologic maps (right).

“Huang He Wan Li Tu”(Pictorial Map of Yellow River),

showing the Yellow River in true proportions, with houses representing population of villages (1 house = 100 families)

China, early Ming Dynasty, facsimile of 1368-1378 original.

Image courtesy of the Library of Congress

History of GIS

In 1854, John Snow depicted a cholera outbreak in London using points to represent the locations of some individual cases, possibly the earliest use of the geographic method.

History of GIS

The early 20th century saw the development of photozincography, which allowed maps to be split into layers, for example one layer for vegetation and another for water.

The early 20th with development of Computer and databases evolution GIS became more interactive and used in each and every domain of daily life.

LIS, Cadastral System, Missile Navigation, Agriculture, Forestry, Soils and hydraulics.

GIS Data Models

Relational Object Relational Vector Raster

Vector data model

A representation of the world using points, lines, and polygons. Vector models are useful for storing data that has discrete boundaries, such as country borders, land parcels, and streets.

Covering the real world Objects in geometry. Each object has location stored with its geom

and properties. Each geometry is connected to its non spatial

attributes

Vector data model

Vector data models are mostly used in Applications.

Unlimited attribute entry for each layer or for each geometry.

Freedom of editing and updating. Low space coverage Real geom preservation of real world entity. Data interoperability makes it more favorable.

Vector data model

Selection of attribute data by choice and ranges. (Arithmetic and Logical operations).

Geometrical calculations handling is very easy and accurate i.e. Area, Length, Distance between some entities, Sum and Average analysis.

Overlay analysis are more accurate and reliable in vectors i.e. Buffer, Union, Intersection and clipping etc.

Vector data model

Raster

Raster is combination of Grids or Cell, covering the area of interest in Rows and columns.

Each Grid Cell holds one value even if it is empty. Cell resolution is given as its size on the ground. Minimum width of real world entity is one cell. Grids may contain number, digit or symbol value to

present data in each grid.

Raster

Raster can store single value in each grid. Arithmetic and logical operations can be perform on

single layer or overlay operations, if data is Numeric. Geometrical analysis also can be done. If more than one entities fall in one grid it causes

real data to be deviated to statistical data. Difficult to edit and large space require to save.

How data becomes Spatial….

Co-ordinates, Projection and Datum

Geographic Components Location Co Ordinate System Projection Geometry Attribute Time

Coordinate System.

Coordinate system is a system which uses one or more numbers, or coordinates, to uniquely determine the position of a point or other geometric element in some space or specific dimensions.

By coordinates we also get facility to visualize the orientation and geometrical analysis.

Co Ordinate System Coordinates are numbers which describe the

location of points in a plane or in space Characteristics of Coordinate system Origin Unit Plane (Dimensions)

Co Ordinate System By 3D we can measure the location of any object

in space and its orientation But still the Einstein concept of Space and Time

is not fulfilled by only 3 Dimensions No instantaneous and temporal aspects are

connected with object so 4th dimension is Time

Co-ordinate System.

Cartesian Coordinates Earth

Coordinate System for Earth

Geographic Coordinate System Projected Coordinate System

Geographic Coordinate System

•Parallels - east to west – 0° at the Equator (0 °-90 °)•Meridians – north to south – 0° at the Prime Meridian (0 °-180 °)•Latitude and longitude are angular measurements made from the center of the earth to a point on the surface of the earth

Coordinate SystemsGeographic vs. Projected Geographic Coordinate Systems (GCS)

Location measured from curved surface of the earth

Measurement units latitude and longitude Degrees-minutes-seconds (DMS) Decimal degrees (DD) or radians (rad) Allows distance analysis

Projected Coordinate Systems (PCS) Flat surface Units can be in meters, feet, inches Distortions will occur, except for very fine

scale maps Allows all geometrical analysis

Map Projection: A map projection is a

mathematical formula for representing the curved surface of the earth on a flat map. wide variety of projections

possible each projection will create a

different type of distortion

Projection Flat maps could not exist without map

projections, because a sphere cannot be laid flat over a plane without distortions

Projections are chosen on the requirements of the Application and measurements to be done and preference of preservation of Geometric Components

Distortions

distance area shape direction

Distortions are inherent in maps The Earth is round, a map is flat

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Map Projections Types

Planar Projection Conical Projection Cylindrical Projection

Geometry It is Geek word (geo = earth, metria = measure)

is a part of mathematics concerned with questions of size, shape, and relative position of figures and with properties of space.

Size Shape Area Length Distance

Datum All calculations and data preparation techniques

would be held on the surface of earth Determination of the shape of earth accurately

was a big problem because results were proofing wrong on ground truthing.

Circular Shape Theory Ellipsoidal Shape Theory Geoidetic shape

Earth

Datum Mathematics and Astronomy has developed the

models and surfaces which present the earth of their area in natural way

A point, line, or surface used as a reference, in surveying, mapping, or geology

Every country has its own datum for accurate calculation and data preparation

WGS 1984 is a datum which represents the earth in accurate shape and is workable for the whole planet

Data Preparation Many softwares are available but some famous

are given Arc View Arc info Map Info Global Mapper Arc GIS ER Mapper We go with Arc GIS, Map info

Arc GIS 9.3

Data Formats in Fields

GPSSurvey SheetsTopographic Sheets

GPS

Complete coverage of Earth for Location. Free for all users. 24 Satellites. 6 Orbits. Minimum 3 satellites are required to response

the hand held device. More satellites are required for more

accuracy.

Survey Sheets and Topographic Sheets Survey Sheets are input for GIS for data

entry and basic source for visualizing the measured values by Surveying tools.

Any error or quality disability, in any aspect becomes permanent for further proceeding.

Topographic sheets are used to view the topological relations between the real world features.

Topology with logic is necessary

Program oriented files

Those files which are viewable and editable only in its relevant program are called Program oriented files.

Shape files. Coverage Files. CAD Files Google Earth files

Coverage Files

Coverage Files was operated by Arc Info. Old data model basic used as Digitizing and Map

making Tool. Data entered by relevant Ticks. Against each Tick spatial and aspatial information

stored in many files behind in memory. One index file preserve the relation of al files. Very difficult to handle and file redundancy consume

huge space. Very slow in process.

Shape Files

There are 6 Files collectively called one shape file. Following 4 are most important

.shp Preserves Geometry. .dbf Preserves attribute data. .shx Creates 1-1 relationship with

each geometry and attribute .prj Preserves Projection.

Faster , efficient, Analysis facility and easy to use.

Program oriented files

Cad files are non topological, non spatial model files.

Used for modeling and information about subjects are stored in separate files.

Google Earth files are spatial files present location only

Non topological, no facility to handle attribute data.

Databases

Databases are not program oriented we can design program for our data in the database to read, edit or analyze.

With the use of GIS all databases are modifying their models and including the spatial aspect also in their packages.

Oracle Spatial, Microsoft Access and My SQL are some examples.

WEB GIS and Mobile GIS

Now for large number of use of GIS in every field Web GIS and Mobile GIS are evolved.

Map Server and web protocols are designed for Web data operations.

Open Geospatial Consortium (OGC) is making standards for WEB GIS data.

Navigation and location applications are accessible remotely by web on mobiles also.

GIS Based Potential Identification System on Rivers, Main Canals and Branch Canals Digital Elevation Model preparation of Punjab. 1 Meter Resolution Imagery Acquisition. Raster Math Reclassification, Water Flow Map,

Slope map and Aspect Map Generation. Data Format Conversion and Parameter Selection. Elevation Query, Maps and Alternate Generation. Decision Making

Finding best location for new Canal, Barrage, Rest house, Office and Dam. DTM Generation. Land Use Map Preparation of Punjab. Data Transformation and Vectorization. Terrain and Surface Analysis. Query Buildation. Ground Truthing. Planning.

GIS Based Flood Disaster Management. Alerting Zones Identification. Identification of cities which are at peak risk. Medical, Food, Pure Water and Shelter

Availability Analysis. Network workability analysis. Finding save places for camping. Development of inundation canals at ideal

places. DEM.

Temporal Water Pollution and Analysis. Time wise data acquisition and preparation of

Geo Database for identifying the danger zones for water pollution.

Steps and Strategies to minimize it. Check balance and Temporal Updating. Proposition of Alternatives to Government,

according to the real world Scenario, Location and Industry.

Bridge Management System

Bridge Management System

Bridge Life Cycle Management System

GIS applications in general domains Emergency Services – Fire, Rescue & Police Environmental – Urban Planning, Agriculture and

pollution Business – Site Location, Delivery Systems Industry – Transportation, Communication, Mining,

Pipelines, Healthcare and Utilities Government – Local, State, Federal, Military Education – Research, Teaching Tool,

Administration.

Wherever Spatial Data Analysis is needed

Thank You for kind attention.

Any Query

Project Phases

Data Collection and Preparation. Data Error Removing and Quality Analysis. Data Transformation conversions. Geometrical and Overlay analysis. Map Generation for Static view for Better

Planning and Decision Making. Interfacing (Including in Future Plans)

Data Ware House

Geometrical and Attribute Data for the following Themes was collected, Prepared and checked.

Punjab District and Tehsil Themes. Irrigation Zones, Circles, Divisions, Sub-

Divisions Boundary Themes. Punjab Rivers theme. Main Canal Theme.

Data Ware House

Distributaries of Punjab Theme. Barrages of Punjab Theme. Escape Channel of Punjab Theme. Minors of Punjab Theme. Water Channels Theme. Railway and Main Roads of Punjab.

Engineering & Computer SectionIRI Physics WingI & P Department, Lahore

Statistical Analysis Maps

Bars

Irrigation Asset Management System. Offices. (Name, Adress, Head, Type, Circle) Rest Houses. (Name, Adress, Headed By, Circle, Status)

Zones. (Name, Manage By) Circles. (Name, Manage By, Zone)

Divisions. (Name, Manage By, Circle, Zone) Sub Divisions (Name, Manage By, Division,Circle, Zone)

Irrigation Asset Management System Main Canals. (Name, Zone, Circle, Div) Branch Canals. (Name, Zone Circle, Div, P_Ch) Distributaries. (Name, Zone Circle, Div, P_Ch) Minors. (Name, Zone Circle, Div, P_Ch)

System Out Puts

Base Data Preparation. Complete Information and Analysis access of

Irrigation Network with one Click. Monitoring Management Analysis Planning Decision Making. Temporal Transactions.

Future Strategies..!

GIS Databases of Lined And Un Lined Canals for Seepage Analysis. Acquisition, Preparation and manipulation of

Lined and Un lined Canals. Seepage Areas Identification by Remote

Sensing on basis of Seepage Signatures. Spatial and Raster Analysis for identification

canal areas with worse seepage values. Ground Truthing, Mapping and Decision

Making about un lined canals.

GIS Based Potential Identification System on Rivers, Main Canals and Branch Canals Digital Elevation Model preparation of Punjab. 1 Meter Resolution Imagery Acquisition. Raster Math Reclassification, Water Flow Map,

Slope map and Aspect Map Generation. Data Format Conversion and Parameter Selection. Elevation Query, Maps and Alternate Generation. Decision Making

Water Flow Direction Map

Finding best location for new Canal, Barrage, Rest house, Office and Dam. DTM Generation. Land Use Map Preparation of Punjab. Data Transformation and Vectorization. Terrain and Surface Analysis. Query Buildation. Ground Truthing. Planning.

GIS Based Flood Disaster Management. Alerting Zones Identification. Identification of cities which are at peak risk. Medical, Food, Pure Water and Shelter

Availability Analysis. Network workability analysis. Finding save places for camping. Development of inundation canals at ideal

places. DEM.

Temporal Water Pollution and Analysis. Time wise data acquisition and preparation of

Geo Database for identifying the danger zones for water pollution.

Steps and Strategies to minimize it. Check balance and Temporal Updating. Proposition of Alternatives to Government,

according to the real world Scenario, Location and Industry.

Classified Water Pollution MapWater Pollution Map

Land Use based Water Discharging Plan Soil Type Data Preparation. Land Use Data Preparation. Cropping Patterns of Agricultural Lands. Ground Water Quality Preparation. Ground Water Level Data preparation. Irrigation Network of Punjab data. Overlay and Proximity Analysis. Planning and Decision Making

Land Use

Thank You…!

Any Query is Welcome…!