basics of gis

Basics of Geographical

Information System

Content Content

The session will cover the following topics:

Concept of GIS– What is GIS, its components

– Functions of GIS software

– Representation of objects in GIS

Probable fields of GIS applications– Contributing disciplines and technologies

Data organization in GIS– Types of Geographic data representation

Desktop GIS

Introduction to ArcView GIS software– Component or modules in ArcView

– Brief functionalities of different modules etc.

GIS = Geographic Information System

Information about places on the Earth's surface e.g population of a country, educational infrastructure

Knowledge about where something is e.g. locations of school or college

Knowledge about what is at a given location e.g. Number of students or teachers and other status

GIS is a computer-based tool for solving real-world problems. A GIS integrates information in such a way that it helps us to understand and find solutions to problems. The objects are stored in a database and dynamically linked to an onscreen map, which displays graphics representing real-world objects.

What is GIS?What is GIS?

Functions of GIS

• Storing• Manipulating• Displaying• Analyze, query and produce outputs GIS is the Information System, whether automated or manual

management of Geographic data (spatial data and associated attribute data) for planning purposes.

GIS is a very powerful Planning Tools used to efficiently analyze and manage (input, store, retrieve, manipulate, analyze and output) geographic information.

GIS solves a problem, supports a decision and helps to plan

The ability to incorporate spatial data, manage it, analyze it, and answer spatial questions is the distinctive characteristic of geographic information systems.

What is GIS?What is GIS?

Trained manpower Data

Maps, images, attribute data

Hardware Like any other hardware with some extra component (big printer, digitizer…)

Software Storing data, analysis tools

Procedures Database development and analysis

Presentation On paper map, digital

Components of a GISComponents of a GIS

Functions of GIS

Data Capture

Store Data

Data Manipulation and Editing

Database Management

Data Integration and Modeling

Database Query and Analysis

Customization and Tools Development

Output Preparation

The GIS is capable of finding solutions to real-world problems. A GIS has the following capabilities:

GIS conceptsGIS concepts

Modeling the space in layers

• Integrate graphics of a feature with its attribute using identifier

GIS concepts (contd.)

Representation of objects in GISRepresentation of objects in GIS

OwnerPerson name

Boundarypolygon

Address H-49, R-27, Banani

registrationDate1/1/1990

id902031

Presenting Geographic DataPresenting Geographic Data

– real world objects with graphics and geographic features

– attributes (tabular format) and relate them with identifiers

GIS data can be represented as:

Graphics

Id Owner name Adress Registration Date Latitude9001274902031 Mr. Karim House - 49. Road - 27, Banani 1/1/1990 22, 25, 459001274902032 Mr. Rahim House - 50. Road - 27, Banani 1/2/1990 22, 27, 55

House location(Point)

id

9001274902031

Tabular format

Road 27 (Line)

Plot Boundary(Polygon)

Geographic features

GIS Application Areas

• Urban Planning, Management and Policy- Zoning, subdivision planning- Tax assessment- Education system

• Environmental Science- Monitoring environmental risk- EIA

• Utility and Civil Engineering - Locating underground facilities- Designing alignment for freeways, transit- Coordination of infrastructure maintenance

• Business - Market analysis- Demographic analysis- Site selection

GIS Application Areas (contd.)

• Health Care

- Epidemiological analysis- Service inventory- Needs analysis

• Real Estate

- Neighborhood land price- Traffic impact analysis- determination of highest and best use of land

• Hydrology- Watershed management, floodplain management- Floodplain zonation- Flood risk and damage assessment- Storm water and groundwater modeling

• Political Science- Analysis of election results- Predictive modeling

Line – river, road, embankment etc.

Point – health center, district headquarters,

wells, educational institute etc.

Polygon – Upazila boundary, parcel

boundary etc.

Line – river, road, embankment etc.

Point – health center, district headquarters,

wells, educational institute etc.

Polygon – Upazila boundary, parcel

boundary etc.

The real world objects can be

represented by different features are:  

Presenting Geographic Presenting Geographic DataData

GIS Data FormatGIS Data Format ArcView GIS has the compatibility of all the ESRI data formats:

Coverages, Shapefiles, Grids,images etc.

ArcView GIS also supports variety of common image format.

ArcView GISArcView GIS

RasterRaster

ShapefileShapefileCoverageCoverage

Internet Map ServicesInternet Map Services

TablesTables

• Shapefiles is compatible file format of ArcView GIS and It is also compatible with ArcGIS.

• Each shapefile stores features belonging to a single feature class.

• Attributes stored in a dBASE table.

• Shapes are represented by different features are:

- Points

- Line, polylines

- Polygons

PointsLine / Polyline Polygon

GIS Data FormatGIS Data Format

Data AnalysisData Analysis• A GIS is able to analyze the spatial relationships among multiple

datasets to answer questions and solve problems.

• There are many types of geographic analysis :- Proximity Analysis

- Overlay Analysis etc.

Proximity analysis

Proximity analysis uses the distance between features to answer questions like: • How many schools are there within 1000 meters of the road? • What is the total number of customers within 10 kilometers of Agora? • What proportion of the wheat crop is within 500 meters of the well?

A 1000-meter buffer is created on either side of the road

to find the schools within the 1000-meter distance.

Which Schools are within 1000 meter of the road

Which Schools are within 1000 meter of the road

ArcView: GIS Software ArcView: GIS Software

• captures spatial data• provides a set of tools for spatial data manipulation • retrieves data from existing or newly created databases• produces thematic maps• supports add-on new modules with extensions.1

ArcView, a product of Environment System Research Institute (ESRI), is a software that provides the basic GIS functionality with an easy-to-use graphic user interface(GUI) which can be customised for specific applications.

Desktop GIS refer to a GIS that can be installed on a desktop computer. It aims to provide the user the GIS analysis, query with mapping facilities.

Capacity

Presenting Geographic Data (cont.)Presenting Geographic Data (cont.)

BWDB Projects

LGED Projects

Presenting Geographic Data (cont.)Presenting Geographic Data (cont.)

Examples of Examples of GIS ApplicationGIS Application

Mapping Arsenic concentration

Examples of Examples of GIS ApplicationGIS Application

Soil Salinity Distribution 1973

Introduction to ArcGIS – Chapter 1

Slide 22

Apr 8, 2023

Examples of Examples of GIS ApplicationGIS Application

Adarsha Gram Location mapping

AG location Bangladesh

ThanksThanks

ReferenceReference

1.1.Geographical Information Systems : David J Geographical Information Systems : David J Maguire, Michael F Goodchild & David W Rhind: Maguire, Michael F Goodchild & David W Rhind: Great Britain, 1994, Vol. 1 & 2Great Britain, 1994, Vol. 1 & 2

2.2.Concepts & Techniques of Geographic Concepts & Techniques of Geographic Information Systems: C.P. LO & Albert K W Yeung: Information Systems: C.P. LO & Albert K W Yeung: India, 2005India, 2005

3.3.Introductory reading in Geographic Information Introductory reading in Geographic Information Systems: D J Peuquet & D F Marble: London, 1993Systems: D J Peuquet & D F Marble: London, 1993