gis program 6th gis workshop introduction to arcgis »gis concept introduction to arcgis »gis...

74
GIS Program GIS Program 6th GIS Workshop 6th GIS Workshop Introduction to ArcGIS » GIS CONCEPT Eng. Hussain Darwish Eng. Hussain Darwish Technical College-Baghdad Technical College-Baghdad

Upload: elizabeth-douglas

Post on 17-Dec-2015

246 views

Category:

Documents


2 download

TRANSCRIPT

GIS ProgramGIS Program6th GIS Workshop6th GIS Workshop

Introduction to ArcGIS

»GIS CONCEPT

Introduction to ArcGIS

»GIS CONCEPT

Eng. Hussain DarwishEng. Hussain DarwishTechnical College-BaghdadTechnical College-Baghdad

Geographic Information SystemsGeographic Information Systems

Eng.Hussain Darwish

Technical College-Baghdad

A Generic Definition of GISA Generic Definition of GIS

• Geographic = spatially referenced data• Information = data processed into a usable

form• System = a framework for manipulating,

analyzing and presentation of information

What is a Geographic Information What is a Geographic Information System (GIS)?System (GIS)?

• A GIS is an organized collection of computer hardware, software, geographic data, and people, to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information.

• A GIS is both a database system with specific capabilities for spatially-reference data, as well [as] a set of operations for working with data . . . In a sense, a GIS may be thought of as a higher-order

map.”

GIS COMPONENTESGIS COMPONENTES

GIS requirementsGIS requirements

1. Data input, from maps, aerial photos, satellites, surveys, GPS, and other sources2. Data storage, retrieval, and query3. Data transformation, analysis, and modeling, including spatial statistics4. Data representation (reporting), such as maps, reports, and plans

• Basic Questions Asked• with a GIS:• • What is at..._____? (Location)• • Where is it..._____? (Condition)• • What has changed...? (Trend)• • Which is the best way...? (Routing)• • What is the pattern...? (Pattern)• • What if...? (Modeling)

What is a Geographic Information What is a Geographic Information System (GIS)?System (GIS)?

• An information system has a full range of functions to:– process observations– process measurements– provide descriptions– explain data– make decisions

CaptureData

GIS ProcessGIS Process

RegisterMap Base

InterpretData

Convert Datato DigitalFormat

Store Datain Computer

ProcessData

DisplayResults

GIS DATAGIS DATA

• SPATIAL (POSITIONAL) DATA

• ATTRIBUTE (TABULAR) DATA

GIS GIS SystemSystem

SpatialSpatialDataDataBaseBase

AttributeAttributeDataDataBaseBase

CartographicCartographicDisplay SystemDisplay System

Geographic Analysis System

Map Map DigitizingDigitizingSystemSystem

ImageImageProcessingProcessing

SystemSystem

StatisticalStatistical Analysis Analysis System System

DatabaseDatabaseManagementManagement

SystemSystem

ImagesImages

MapsMaps

MapsMaps

StatisticalStatisticalReportsReports

StatisticsStatisticsTabular DataTabular Data

GIS Data FormatGIS Data Format

• There are two formats used by GIS systems to store and retrieve geographical data:

– Raster data

– Vector data

Spatial Data Model: Basic Data Spatial Data Model: Basic Data FormatFormat

• GIS are driven by spatial data

• Two basic spatial (coordinate/geometric) data exist– Vector: based on geometry of

• points• lines • polygons

– Raster: based on geometry of• grid cells (images, bitmaps, DEMs)_

Raster FormatRaster Format

• Data are divided into cell, pixels, or elements

• Cells are organized in arrays• Each cell has a single value• Row and Column Numbers are used to

identify the location of the cell within the array.

• Perhaps the most common example of raster data is a digital image.

Vector FormatVector Format

• Data are associated with points, lines, or boundaries enclosing areas (polygons)

• Points are located by coordinates• Lines are described by a series of

connecting vectors (line segments described) ,by the coordinates of the start and end point

• Areas or polygons are described by a series of vectors enclosing the area.

Vector FormatVector Format

• Any number of factors or attributes can be associated with a point line or polygon.

• Data are stored in two files:– a file containing location information– a file containing information on the attributes

• A third file contains information needed to link positional data with their attributes.

GIS Data TypesGIS Data Types

• Features– Point datasets– Line datasets– Polygon datasets

• Surfaces– Grid datasets– TIN datasets– Images datasets

• Networks– Simple denstritic networks– Simple loop networks

Vector and Raster Representation Vector and Raster Representation of of Point Point Map FeaturesMap Features

Map FeatureGIS Vector

FormatGIS Raster

Format

(X,Y)Coordinate in space

Cell Located in an Array row and column

Point FeaturesPoint Features

• All points required to define the feature geometry have to be stored as part of the feature definition.

Point FeaturesPoint Features

• Point datasets

One-to-one relation between features in

the map and records in the table.

Vector and Raster Representation Vector and Raster Representation of of LineLine Map Features Map Features

Map FeatureGIS Vector

FormatGIS Raster

Format

Line FeaturesLine Features

• Line datasets

One-to-one relation between features in the map and records in the

table.

Vector and Raster Representation Vector and Raster Representation of of AreaArea Map Features Map Features

Map FeatureGIS Vector

FormatGIS Raster

Format

Area FeaturesArea Features

• Polygon datasets

One-to-one relation between features in the map and records in the

table.

Surfaces FeaturesSurfaces Features

• Grid datasets

Data Structure of SurfacesData Structure of Surfaces

• Grid datasets:– Cellular-based data structure composed of square cells of

equal size arranged in rows and columns.– Grid definition requires: (1) the coordinates of the upper-

left corner, (2) the cell size, (3) the number of rows, (4) the number of columns, and (5) the value at each cell.

– Cells that do not store any value are called NODATA cells.

Number of columns

Num

ber

of

row

s

Cell size

(x, y)

Surfaces FeaturesSurfaces Features

• TIN datasets

• Triangular Irregular Network (TIN) Datasets:– Dataset constructed by connecting points -- for which the TIN

parameter is known – forming triangles.– Triangle sides are constructed by connecting adjacent points

so that the minimum angle of each triangle is maximized.– Triangle sides cannot cross breaklines.– The TIN format is efficient to store data because the resolution

adjusts to the parameter spatial variability.

Data Structure of SurfacesData Structure of Surfaces

• Triangular Irregular Network (TIN) Datasets

Data Structure of SurfacesData Structure of Surfaces

Image Surface FeaturesImage Surface Features

• Image datasets

Data Structure of SurfacesData Structure of Surfaces• Image datasets:

– ARC Digitized Raster Graphics (ADRG)

– Windows bitmap images (BMP) [.bmp]

– Multiband (BSQ, BIL and BIP) and single band images [.bsq, .bil and bip]

– ERDAS [.lan and .gis]

– ESRI Grid datasets

– IMAGINE [.img]

– IMPELL Bitmaps [.rlc]

– Image catalogs

– JPEG [.jpg]

– MrSID [.sid]

– National Image Transfer Format (NITF)

– Sun rasterfiles [.rs, .ras and .sun]

– Tag Image File Format (TIFF) [.tiff, .tif and .tff]

– TIFF/LZW

NetworksNetworks

• Simple networks

NetworksNetworks

• Simple loop networks

Data Structure of FeaturesData Structure of Features

A line is an open sequence of points in which the first and last points are called nodes, and the remaining intermediate points are called vertices.

Nodes

Vertices

Data Structure of FeaturesData Structure of Features

• Simple lines• Complex lines

Data Structure of FeaturesData Structure of Features

• Simple polygons

• Complex polygons

Data Structure of FeaturesData Structure of Features

• Space-filling polygons

• Not space-filling polygons

Data Structure of FeaturesData Structure of Features

CB

A

D

1

2

3 4

5

I

II

III

Line From- Node To- Node Right Polygon Left Polygon

1 B A I I I I

2 D A I I I I

3 B D I I I

4 D C I I I I I

5 C B I I I I I

• Line and polygon topology

Data Structure of NetworksData Structure of Networks• Simple loop networks:

– System of simple lines -- called links -- connected at their nodes.

– Links can point in either direction or in both directions.

A B

E

I

J

K

D

C

G

H

1

F

1

2 3

45

6

78

9

1011

12

Vector and Raster FormatsVector and Raster Formats

• Most GIS software can display both vector and raster data.

• Raster formats are efficient when comparing information among arrays with the same cell size.

• Raster files are generally very large because each cell occupies a separate line of data.

• Vector formats are efficient when comparing information whose geographical dimensions are different.

Vector Data ModelVector Data Model

• Major types (formats) of vector data available in ArcGIS– ESRI GeoDatabases– ESRI shapefiles– ArcInfo coverages and libraries– CAD files (AutoCAD DWG, DXF;

Microstation DGN)– StreetMap files– Spatial Database Engine (SDE) data– ASCII point coordinate data– Linear measure (route) data_

Vector Data ModelVector Data Model

• Characteristics of the vector data model:– + Features are positioned accurately– + Shape of features can be represented correctly– + Features are represented discretely (no fuzzy

boundaries)– – Not good for representing spatially continuous

phenomena– – Potentially complex data structure (especially

for polygons); can lead to long processing time for analytical operations_

Raster Data ModelRaster Data Model

• Raster spatial data model– origin is set explicitly– cell size is always known– cell references

(row/column locations)are known

– cell values are referencedto row/column location

– values represent numerical phenomena orindex codes for non-numerical phenomena_

Raster Data ModelRaster Data Model

• Characteristics of the raster data model:– Rectangular grid of square cells– Shape of discrete polygonal features

generalized by cells– Continuous (surface) data represented easily– Simple data structure_

Raster Data ModelRaster Data Model

• Raster data are good at representing continuous phenomena, e.g.,

– Elevation, slope, aspect– Soil types.– Electromagnetic reflectance (photographic or

satellite imagery)– Radar images.– Continuous phenomena

Comparison of Raster and Vector Comparison of Raster and Vector FormatsFormats

• Raster formats are efficient when comparing information among arrays with the same cell size.

• Raster files are generally very large because each cell occupies a separate line of data, only one attribute can be assigned to each cell, and cell sizes

are relatively small.

• Vector formats are efficient when comparing information whose geographical shapes and sizes are different.

• Vector files are much smaller because a relatively small number of vectors can precisely describe large areas and a many attributes can be ascribed to these areas.

RasterRaster VectorVector

Comparison of Raster and Vector Comparison of Raster and Vector FormatsFormats

• Raster representations are relatively coarse and imprecise

• Vector representations of shapes can be very precise.

RasterRaster VectorVector

Most GIS software can display both raster and vector data. Only a limited number of programs can analyze both types of data or make raster type analyses in vector formats.

Attributes dataAttributes data

Types of Attributes data

• Numeric data ( e.g. size, area, temperature,…etc.).

• Semantic data (e.g. class, type, name, quality…etc.).

Each of them may be stored in a coded manner.

• The “where” of GIS is determined by coordinate (map) data structures, but …

• The “what” of GIS is determined by tabular (relational database) data structures

• Thus, tabular data are just as important as coordinate data.

Relational Database Model & Attribute Data Relational Database Model & Attribute Data StructuresStructures

Relational Database Model & Relational Database Model & Attribute Data StructuresAttribute Data Structures

• Attribute data are stored in database tables.

• Tables are composed of:

– fields(columns)

and

– records(rows)_

Relational Database Model & Relational Database Model & Attribute Data StructuresAttribute Data Structures

• Each vector data source has an attribute table

Relational Database Model & Relational Database Model & Attribute Data StructuresAttribute Data Structures

• You may already be familiar with some types of relational databases– dBase– rBase– MS Access– MS Excel (database functionality)– Oracle, INFORMIX, INGRES, SQL Server– MySQL, PostgreSQL– INFO (in ArcInfo)_

Relational Database Model & Relational Database Model & Attribute Data StructuresAttribute Data Structures

• Tables can be linked and joined (“related”) by use of common values in fields

Relational Database Model & Relational Database Model & Attribute Data StructuresAttribute Data Structures

• Different types data that may have attribute tables in ArcGIS– Vector

• point attribute• polygon attribute• line attribute• node attribute* • text attribute*• route & event*• CAD attributes

– Raster• value attribute tables*_

* in ArcInfo coverage & grid data only

What is a Geographic Information What is a Geographic Information System (GIS)?System (GIS)?

• In a geographic information system, information is characterized spatially.

• In a GIS the common purpose is decision making to manage: – land– resources– transportation– OR any other spatially distributed activity

GIS APLLICATIONGIS APLLICATION

• Examples of application of automated methods

include a wide range:

engineering

mining

natural resource management

agriculture

planning (all gov’t levels)

etc...

GIS ApplicationGIS Application

• … but generally can be grouped into four basic categories:

• NATURAL RESOURCE MANAGEMENT» Forest & Wildlife» Hydrological» Minerals

• URBAN & REGSIONAL MANAGEMENT» Land Use Planning/Environmental Impact» Public Works» Emergency Response» Legal Records» Transportation and network management

GIS ApplicationGIS Application

• COMMERCIAL» Market Area Analysis» Site Selection» Routing

• AGRICULTURAL MANAGEMENT» Field Records» Animal Management» Climate Change / Human Impact

History of GISHistory of GIS

Decade Milestones for computer-based GIS

1960’s -Canada Geographic Information System (CGIS) developed: national land inventory pioneered many aspects of GIS-Harvard Lab for Computer Graphics and Spatial Analysis: pioneered software for spatial data handling-US Bureau of Census developed DIME data format-ESRI founded

1970’s -CGIS fully operational (and still operational today)

-First Landsat satellite launched (USA)

-First geocoded census

-USGS begins Geographical Information Retrieval and Analysis System (GIRAS) to manage and analyze large land resources databases and Digital Line Graph (DLG) data format

-ERDAS founded

-ODYSSEY GIS launched (first vector GIS)

History of GISHistory of GIS

Decade Milestones for computer-based GIS

1980’s -ESRI launches ARC/INFO (vector GIS)

-GPS became operational

-US Army Corp of Engineers develop GRASS (raster GIS)

-MapInfo founded

-Burrough’s book on “Principles of [GIS] for Land Resources Assessment” published

-First SPOT satellite launched (Europe)

-Idrisi Project started (GIS program)

-SPANS GIS produced

-National Center for Geographic Information and Analysis (NCGIA) established in USA

-first release of US Bureau of the Census TIGER digital data products

• History of GIS

Major GIS-Only JournalsMajor GIS-Only Journals

• International Journal of Geographical Information Systems

• Geographical Systems• Transactions in GIS• Geo Info Systems• GIS World

ArcView BasicsArcView Basics

Project (the foundation. Contains the documents)

Views

Tables

Charts

Layouts

Scripts

the actual data.Contains geographical features of the same kind (points, lines or polygons) and their attributes

Themesdisplay and query spatial data.contains multiple themes (i.e. layers of data).

compile maps for printing

contain the attribute data of a theme

Introduction to GIS (1)Introduction to GIS (1)

• Four basic steps for map production

– Data Collection

– Data Display / Explore

– Data Analysis

– Map Composition

• . • .

Map Characteristics In addition to feature locations and their attributes, the other technical characteristics that define maps and their use includes:

• Map Scale • Map Accuracy • Map Extent and • Data Base Extent

• Fundamentals of GIS•

Mapping Concepts, Features & Properties A map represents geographic features or other spatial phenomena by graphically conveying information about locations and attributes. Locational information describes the position of particular geographic features on the Earth's surface, as well as the spatial relationship between features, such as the shortest path from a fire station to a library, the proximity of competing businesses, and so on. Attribute information describes characteristics of the geographic features represented, such as the feature type, its name or number and quantitative information such as its area or length.

Thus the basic objective of mapping is to provide • descriptions of geographic phenomenon • spatial and non spatial information • map features like Point, Line, & Polygon

Map FeaturesMap Features• Map Features

Locational information is usually represented by points for features such as wells and telephone pole locations, lines for features such as streams, pipelines and contour lines and areas for features such as lakes, counties and census tracts.

Point feature A point feature represents as single location. It defines a map object too small to show as a line or area feature. A special symbol of label usually depicts a point location.

Line feature A line feature is a set of connected, ordered coordinates representing the linear shape of a map object that may be too narrow to display as an area such as a road or feature with no width such as a contour line.

Area feature An area feature is a closed figure whose boundary encloses a homogeneous area, such as a state country soil type or lake

Where GIS is being Applied l:Where GIS is being Applied l:

• Urban Planning, Management & Policy• Zoning, subdivision planning• Land acquisition• Economic development• Code enforcement• Housing renovation programs• Emergency response• Crime analysis• Tax assessment

Where GIS is being Applied: IIWhere GIS is being Applied: II

• Environmental Sciences• Monitoring environmental risk• Modeling storm water runoff• Management of, floodplains,

wetlands, forests. • Environmental Impact Analysis• Groundwater modeling and

contamination tracking

Where GIS is being Applied: IIIWhere GIS is being Applied: III

• Political Science• Redistricting• Analysis of election results• Predictive modeling• Civil Engineering/Utility• Locating underground facilities• Designing alignment for freeways, transit• Coordination of infrastructure maintenance

Where GIS is being Applied: IVWhere GIS is being Applied: IV

• Business• Demographic Analysis• Market Penetration/ Share Analysis• Site Selection• Education Administration• Attendance Area Maintenance• Enrollment Projections• School Bus Routing

Where GIS is being Applied: IVWhere GIS is being Applied: IV

• Real Estate

• Neighborhood land prices

• Traffic Impact Analysis

SummerySummery

• Contributing Disciplines to• GIS• • Landscape Ecology• • Geography• • Cartography• • Remote Sensing• • Photogrammetry• • Surveying• • Geodesy• • Statistics• • Operations Research• • Computer Science• • Mathematics• • Civil Engineering

SummerySummery

• GIS As A Set Of• Interrelated Subsystems:• 1. Spatial and Attribute Data Base• 2. Cartographic Display System• 3. Map Digitizing System• 4. Database Management System• 5. Geographic Analysis System• 6. Image Processing System• 7. Statistical Analysis System• 8. Decision Support System