GIS technology. Introduction to GIS

Transcription

1 GIS technology Introduction to GIS 1

2 GIS Technology What is GIS Components of GIS Functions of GIS Benefits of GIS Real World Applications 2

3 What is GIS? A Geographic Information System (GIS) is a collection of computerized maps and databases that are linked together for the purpose of storing, retrieving, managing and analyzing information. 3

4 What is GIS? A GIS is a technological field that incorporates geographical features with tabular data in order to map, analyze, and assess real-world problems. The key word to this technology is Geography this means that some portion of the data is spatial. In other words, data that is in some way referenced to locations on the earth. 4

5 What is GIS? In the strictest sense, a GIS is a computer system capable of assembling, storing, manipulating, and displaying geographically referenced information, i.e. data identified according to their locations. Practitioners also regard the total GIS as including operating personnel and the data that go into the system. USGS 5

6 Interpretation of the words GIS: A particular form of information system applied to geographical data A system: A group of connected entities and activities which interact for a common purpose An information system: A set of processes, executed on raw data, to produce information which will be useful for decision making Geographical data: Spatially referenced data sets 6

7 What is GIS? What Is a Geographic Information System? 7

8 Sample overlay 8

9 GIS (Describing Our World) We can describe any thing of our world in two ways: Location Information: Where is it? 51 N, 112 W Attribute Information: What is it? Species: Oak Height: 15m Age: 75 Yrs 9

10 Forget about Maps! Geographic Information Systems are driven by the data linked to the maps. Databases 80% Maps 20% 10

11 Did you Know? Approximately 80% of ALL data stored is related to a geographic location. 11

12 GIS a system A GIS is an information system Its common purpose: decision making for managing use of land, resources, or any spatially distributed activities or phenomena It processes raw geographical data It produces information for decision making of spatial activities 12

13 The technical concerns Spatial is special Geospatial subset of spatial (on earth) Technical matters Multi-dimensional Voluminous Projected onto a flat surface Special methods of analysis Large variety of geographical information Updating is complex and expensive Visualisation and map making requires large amount of data 13

14 GISystems, GIScience and GIStudies, GIServices GISystems Emphasis on technology and tools Emphasising infrastructure GIScience Emphasising principle and theory Fundamental issues raised by the use of GIS and related technologies Spatial analysis Map projections Accuracy Scientific visualization GIStudies Systematic study of the use of geographic information. Emphasising data and data mining GIServices Emphasising socio-economic service

15 What can a GIS do?(5w) Condition (What is it...) Location (Where is it...) Trend (What has changed...,what trends are occuring) Pattern (What is the pattern..., What is nearby?) Modeling (What if...)

16 Why is GIS Important? Provides a consistent framework for integrating spatial and other kinds of information within a single system (ideal for interdisciplinary work). Permits manipulation and display of geographical (digital) data in new ways. Makes connections between activities based on geographic location.

17 Why Use GIS? GIS is not...simply a computer system for making maps, although it can create maps at different scales, in different projections, and with different colors. GIS is much more than mapping software. Maps are only one of three views of a GIS. When deployed with a clear strategy, GIS is a technology that can change an organization fundamentally and positively. 17

18 Three Views of a GIS A geographic information system supports several views for working with geographic information. Geodatabase view Geovisualization view Geoprocessing view 18

19 Three Views of a GIS 19

20 Where is a GIS from?(origin of GIS) Geography Cartography CAD and computer graphics Surveying and photogrammetry Remote sensing and space technology..other Systems 20

21 GIS & Others Science and Technology 21 RS CAD GIS CAC DBM 1 أنظمة التصميم بمعونة الحاسب :Computer Aided Design تتيح الوصول إلى قواعد البيانات ولكن بشكل محدود إمكانياتها التحليلية محدودة. 2 األنظمة الكرتوغرافية :Computer Cartography بنية المعلومات فيها بسيطة وتفتقر إلى العالقات المكانية.topology قدراتها التحليلية محدودة. 3 أنظمة إدارة قواعد البيانات Database management systems :)DBMS) تخزن وتجمع وتعالج البيانات الوصفية إمكانياتها الرسومية محدودة وتفتقر إلى إمكانية التحليل الجغرافي. 4 أنظمة االستشعار عن بعد :Remote sensing systems تجمع وتخزن وتعالج البيانات النقطية raster data تفتقر هذه األنظمة إلى القدرة على معالجة البيانات الشعاعية ( vector ) data إمكانية ربطها مع البيانات الوصفية محدودة.

22 A brief history of GIS The era of innovation 1960s 70s The era of commercialization 1980s 90s The era of exploitation The 21 st century 22

23 GIS Technology What is GIS Components of GIS Functions of GIS Benefits of GIS Real World Applications 23

24 Components of a GIS Software ArcMap, IDRISI, MapInfo, etc. Scientists, GIS technicians, etc. Data People Raster, vector, x,y 24 tables, etc. Hardware Digitizer, scanner, PC, etc.

25 1. Hardware Digitizer Printer Computer Scanner Plotter 25

26 1. Hardware 26

27 2. GIS Software 27 ESRI:Products, used by 77% of GIS professionals. ArcView, ArcGIS, ArcSDE. IDRISI: Proprietary GIS product developed by Clark Labs. Geomedia: (INTERGRAPH), Products, used by 18% of GIS professionals. Autodesk: World (Autodesk) Mapinfo Pro: Products, used by 20% of GIS professionals GeoConcept: (Geoconcept)

28 3. GIS Data GIS Data Models Attribute Data Spatial Data Vector Data Raster Data Point, Polyline, Polygon Pixel: Picture Element Type of Storing: Shape file:.shp Personal &File geodatabase:. mdb, gdb Coverage: dwg, dxf, dgn Type of Storing:.jpeg,img,tiff, gif,ecw,bmp,.. 28

29 3. Spatial Data : GIS stores and manages geographic data in a number of formats. The two basic data models that ArcGIS uses are Vector, Raster. Geographic coordinates Tabular attributes 29

30 3. Spatial Data Spatial data can be in either vector or raster format: Vector format is used when a feature has shape and size (can be point, line, or polygon) and is stored in a shapefile (*.shp) 30 Raster format is used when data has no distinct shape (e.g. rainfall, wind, temperature, greenness, etc.) and is often stored as an image file (*.img)

31 Vector vs. Raster Data Representation Raster data are described by a cell grid, one value per cell Vector Raster Point Line Polygon Zone of cells 31

32 Vector data Points are pairs of x,y coordinates. Lines are sets of coordinates that define a shape. Polygons are sets of coordinates defining boundaries that enclose areas. 32

33 3.1 Data Types :Vector Data Points, Lines and Areas represent entities Points - City, Tree Lines - River, Road Areas - Forest, Lake 33

34 Data Types :Vector Data 34 Points Zero-dimensional - represents a site Lines One-dimensional has length but no width Polygons Two-dimensional an area Volumes Three-dimensional occupies an area and has a vertical component

35 Point A point object has neither length nor breadth nor depth. May be used to indicate spatial occurrences or events, and their spatial pattern. 35

36 Line A line object has length, but not breadth or depth. Used to represent linear entities that are frequently built together into networks. Also used to measure distances between spatial objects. 36

37 Area An area object has two dimension, length and breadth, but not depth. Represents enclose areas of natural or artificial objects. 37

38 Volume A volume object have length, breadth and depth. Used to present natural (e.g. mine bodies and buildings) or artificial objects. 38

39 Vector data formats Vector data formats for storing point, line, and polygon features. These formats include: Shapefiles Geodatabases Coverages(cad files,dgn) Event tables Triangulated Irregular Networks (TINs) 39

40 Spatial file formats- Example- ArcCatalog view Personal Geodatabase Feature data set Feature class (feature type = polygon) Feature class (feature type = arc) Coverage (= feature class) Feature type (arc) Feature type (point) Feature type (polygon) Feature type (point) Coverage (= feature class) Feature type (arc) Feature type (point) Locator (table) Raster Shapefile Shapefile 40

41 Type of storing of Vector Data : ArcGIS from ESRI uses three different implementations of the vector model to represent feature data: Shapefiles:.shp Geodatabases:.mdb,gdb and Coverages: dwg; dxf 41

42 1. Vector data 1.1 Shapefiles Shapefiles are stored in folders. A shapefile consists of a set of files of vector data in the shapefile and a dbase.dbf file containing the attributes of the features. Each constituent file shares the shapefile name. Shapefiles are stored in three to five files (with extensions.shp,.shx,.dbf,.sbx and.sbn). 42

43 1.2 Geodatabases: Some advantages of a geodatabase are that features in geodatabases can have built-in behavior; geodatabase features are completely stored in a single database; and large geodatabase feature classes can be stored seamlessly, not tiled. In addition to generic features, such as points, lines, and areas, you can create custom features such as transformers, pipes, and parcels. Storage of geodatabase features 43

44 Geodatabase types: Manages features and tables inside a database management system Personal geodatabase stores datasets in a Microsoft Access.mdb file storage sizes between 250 and 500 MB limited to 2GB only supported on Windows some higher level GIS functions can only be performed if a geodatabase is created 44

45 Geodatabase types: File geodatabase o stores datasets in a folder of files o each dataset a file up to 1 TB in size o can be used across platforms o can be compressed and encrypted for read-only, secure use o ESRI s recommended choice ArcSDE geodatabase stores datasets in a number of optional DBMSs: IBM DB2, IBM Informix, Microsoft SQL Server, Oracle, or PostgreSQL unlimited size and users 45

46 1.3 Coverages you can see that a_workspace contains two coverages: a_coverage and b_coverage. The a_coverage contains an arc feature class and a tic feature class. This coverage has polygon topology, so it contains a polygon feature class and a label feature class as well. The dataset b_coverage is a line coverage, so it just contains arc and tic feature classes. 46

47 3.2 Data Types :Raster Data Grids represent entities Grids made of cells Value applied to cell 47

48 Raster data In a Raster model, the world is represented as a surface that is divided into a regular grid of cells. The x,y coordinates of at least one corner of the raster are known, so it can be located in geographic space. 48

49 Raster data Raster models are useful for storing and analyzing data that is continuous across an area. Each cell contains a value that can represent membership in a class or category, a measurement, or an interpreted value. Raster data includes images and grids. Images, such as an aerial photograph, a satellite image, or a scanned map, are often used for generating GIS data. The smaller the cell size for the raster layer, the higher the resolution and the more detailed the map but increases the total volume of data that must be stored. 49

50 Type of storing of Raster: Image Datasets Supported image formats: Windows bitmap images (BMP) [.bmp] ERDAS [.lan and.gis] ESRI Grid datasets IMAGINE [.img] 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 GIF Graphic Interchange Format 50

51 Two Types of Data Models Used in GIS Vector Data Discrete features Points: wells, Tel. poles Lines: roads, rivers Areas: landuse, veg. types, soil types Uses points with x, y coordinates Raster Data Continuous features Uses grids and cells with unique values Rainfall, surface elevation, depths, soil erosion Simple data structure (rows & columns) File size depends on cell (pixel) resolution 51

52 Advantages (Vector) Good Representation of data. Use small File Size. Accurate map output. Disadvantages (Vector) Complex Data Structure. Expensive Technology. Analysis is Complex. 52

53 Advantages (Raster) Simple Data Structure. Cheap Technology. Analysis is Simple. Same grid cell for several attributes. Disadvantages (Raster) Large Data Volume. Inefficient use of computer storage. Difficult network analysis. Less accurate or attractive maps. Loss of information when using large cells. 53

54 Triangulated Irregular Networks (TIN): TIN: is a series of triangles capturing the topography.. x, y, z at nodes. Each triangle has a defined slope and direction (aspect). DEM : Digital Elevation Model data are stored and processed as raster GRIDS 54

55 4. People using GIS 55 Government Tax maps; economic development; housing; law enforcement; health Science Meteorology; biology; geology; geophysics; education Business Retailing; marketing Logistics Transportation; disaster preparation Environment Landuse changes; water quality; pesticide monitoring; soil erosion; air pollution

56 GIS Technology What is GIS Components of GIS Functions of GIS Benefits of GIS Real World Applications Application of GIS in Transport 56 56

57 Functions of a GIS Spatial data is the fuel of GIS. Input :Data Input - aerial photography, scanning, digitizing, GPS or global positioning system. Storage: hardcopy can be stored flat in map drawers. Digital data can be stored on CD, diskette or on your hard drive). Manipulation( digital geographic data can be edited)

58 Functions of a GIS Query & Analyze: see later Visualization : The ability to display your data, your maps, and information about them

59 Input Data: Scanner, Digitizer, GPS Table Digitizing traces objects on a paper map Uses a digitizing tablet Heads-up Digitizing traces objects on the screen Scanned map, air photo or satellite image 59 59

60 Global Positioning Systems GPS is a revolutionary navigation System 24 satellites orbiting the earth Provide location within meters anywhere on the globe. Now available in many cars as an option 60 60

61 Earth Observation SPOT Systeme Pour l Observation de la Terre Landsat (TM) RadarSAT - Canadian made satellite system NOAA National Oceanic and Atmospheric Association ERS European satellite ERS NOAA SPOT LANDSAT RADARSAT 61 Geo Eye 61

62 Query & Analysis: City maps in action What is the fastest way to get to a fire? 62 62

63 Query & Analysis : City maps in your neighborhood What are the best routes for your school buses in order to get everyone home the fastest? 63 63

64 Query & Analysis : City maps

65 GIS - Query & Analysis GIS software can answer questions about our world: Attribute Questions: What provinces have more than 1.5 million people? Spatial Questions: What provinces border Saskatchewan? 65 65

66 Query & Analysis Planning the best location for a new ball park 66 66

67 Query & Analysis Study of drainage systems 67 67

68 Query & Analysis Evaluate areas most susceptible to landslide 68 68

69 Query & Analysis Nuclear waste site planning 69 69

70 Data View and Output General map Thematic map Unique values Graduated color and symbol Proportional Symbols Pies and Charts 70 70

71 Display and Symbolizing Single Symbol 71 71

72 Display and Symbolizing Qualitative symbology Unique values Unique values but many fields Matching to symbols in a style 72 72

73 Display and Symbolizing Quantitative symbology Graduated Colors Graduated Symbols Proportional Symbols Dot Density 73 73

74 Display and Symbolizing Charts (Multiple attributes) Pie Bar/column Stacked Multiple attributes 74 74

75 Data Presenting Graphs Bar/column graphs Line graphs Pie graphs 3D graphs Reports 75 75

76 GIS Technology What is GIS Components of GIS Functions of GIS Benefits of GIS Real World Applications 76 76

77 Benefits of GIS The Importance of Using GIS Less Data Redundancy More Timely Information Easy Analysis of Information Improved Management of Resources Adaptable to Change Expanded Opportunities for Analysis Simulation and Modeling Valuable Tool for Decision Management 77 77

78 Benefits of GIS The Importance of Using GIS Revision and updating easier Search, analysis and representation easier More value added products Data can be shared and exchanged Productivity more improved Time and cost saved Better decision making 78 78

79 Advantages of GIS GIS allows us to view, understand, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts. A GIS helps you answer questions and solve problems by looking at your data in a way that is quickly understood and easily shared. GIS give the accurate Data. Better Predictions and Analysis. 79

80 Real World Applications Public Utilities Emergency 911 Health Care Environmental Environmental Map Agriculture Marketing Real Estate 80 80

81 Real World Applications The application of GIS is limited only by the imagination of those who use it. Jack Dangermond, President of ESRI 81 81

82 One day in life with GIS 82

83 One day in life with GIS 83

84 Public Utilities Is it safe to dig here? A proposed excavation, identified by address, is compared to pipelines in the area using Geotechnology

85 Emergency 911 What is the fastest route to the Hospital? Geotechnology can choose the fastest route to a hospital. The GIS can take into account traffic and other impediments

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87 87 87

88 Health Care What Communities are at risk from Disease? 88 Geotechnology identifies communities at risk of River Blindness and helps determine the impact of treatment. 88

89 Environmental What are the effects of Global Warming? 89 Land cover and temperature relationships are made clear when the data are seen at once using Geotechnology. 89

90 Agriculture How can I improve food production? 90 Geotechnology is used in making crop management decisions to maximize yields and minimize fertilizer input. 90

91 Tsunami Relief 91 91

92 Hurricane Tracking and Response 92 92

93 Marketing How can I optimize my Marketing Campaign? 93 Geotechnology can query a database and identify only those areas with the highest household income within a specified distance of a store. 93

94 Real Estate Where is my Dream Home? With Geotechnology, an agent can show a map of a neighborhood and a picture or video of the actual properties

95 GIS Applications for Transportation 95 95

96 Transportation Evaluate traffic flow 96 96

97 Transportation Provide maps for a corridor study 97 Graphic: ESRI Map Book 97

98 Transportation GIS can be web enabled to display traffic counts 98 98

99 Transportation GIS can be web enabled interactively display accident locations and driving alerts

100 Transportation GIS assist with project management and budgeting

101 Transportation Determine the drive-times

102 The seven parts of every Research Project Objective, explains the purpose of the research and why it is important Usually includes Hypotheses: possible explanations which you will test Literature Review, identifies the key pieces of existing research relevant to the project and the hypotheses Data Sources, identifies and explains the data used. Analysis and Methodology, explains the methodology applied to the data. Results, describes the main research findings, whether or not the hypotheses were upheld, and any potential problems or shortcomings Conclusion, discusses the implications of your results relative to your initial project objective. References, provide standard format citations for all resources used in the project. 102

103 Thank You 10