introduction to gis _ 2014

An Introduction To Some New Era FieldsPart _ 2A

Presented By: Atiqa Ijaz Khan

Wednesday, April 12, 2023PIAIP_NESPAK 2

PART - 02

Geographic Information System


Geographic Information System (GIS)

Introduction to Basics


We Live in Two WorldsNatural World Constructed World

. . . These Are Increasingly In Conflict

GIS


GIS Main Points

A map with a database behind it. A virtual representation of the real world and its infrastructure. A consistent “as-built” of the real world, natural and manmade.

A GIS can: create, edit, query, analyze, and display map information on the computer


GIS “S”

SystemTechnology for the

acquisition and management

ScienceTheory and concepts

behind the technology

Studies Social, legal and ethical issues


RASTER VS VECTORS

Raster

Discrete values

Attribute Numeric values

Non-text values

Abrupt change

Generalized values

No true shape and size

Vector

Continuous values

Point, line, polygon

Attribute Numeric

Text

Gradual change

Maintains of true, Relative, shape and size


The WorldGeographicKnowledge

Citizens

Inventory

Decision Support


How GIS Describe The Data?

SPATIAL DATA WHERE IT IS?

Locational Data

Representation of Read Data in terms of Coordinates

Geographic (lat/long)

Projected (meters, feet)

Geographic Data (on the surface of the Earth)

Geo-spatial Data (range of data from Earth to Space)

ASPATIAL DATA WHAT IT IS?

Attribute Data

Numeric

Text

Non-spatial data

Stands on the basis of Database


Cont.


Geographic coordinates

Tabular attributes

Geographic Data Model

Digital Orthophoto

Streets

Hydrography

Parcels

Buildings

Zoning

Utilities

Administrative Boundaries


KEY PROPERTIES OF SPATIAL DATA

Key Properties of Spatial data

Projection

3D earth into 2D map

Accuracy

How well does the database

info match the real world

Scale

Ratio of distance on a map to the

equivalent distance on the

ground

Resolution

The size of the smallest feature

able to be recognized


In Short Summary of GIS

“GIS is much more than a container of maps in digital form”. “A GIS is a computerized tool for solving geographic problems” “GIS is a spatial decision support system” “GIS is a tool to automate time-consuming tasks that are too tedious or expensive

or inaccurate if performed by hand”


Cont.

In GIS we usually go with the processing of data, analyzing it, and generating a spatial and non-spatial data out of our input data.

No dealing with the acquisition of the data.

It is a decision making tool.

It is also a geo-database with temporal analysis.


THE END


REFERENCES

1. Using Geographic Information System (GIS) to Manage Civil Engineering Projects By Asmaa Abdul Jabbar

2. Longley et al (2005) Geographic Information Systems and Science. 2nd Edition. John Wiley and Sons Ltd. (Chapter 14, pages 317-319)

3. www.esri.com/engineering4. http://webhelp.esri.com/arcpad/8.0/userguide/index.htm#capture_devices/

concept_intro.htm

Special AcknowledgementIndustrial partners: ESRI, Danish Hydraulic Institute, Camp, Dresser and McKee, Dodson and AssociatesGovernment partners:

Federal: EPA, USGS, Corps of Engineers (Hydrologic Engineering Center)State: Texas Natural Resource Conservation Commission, Texas Water Development

BoardLocal: Lower Colorado River Authority, City of Austin, Dept. of Watershed Protection

Academic Partners: University of Texas, Brigham Young University, Utah State University


Any Quires

introduction to gis _ 2014

Education

feet geographic data

input data

processing of data

geographic problems

locational data representation

conflict gis

space aspatial data

gis s system technology