GIS: An Overview. Mr. Mic Ivan V. Sumilang, EnP Senior Research Specialist Phil LiDAR 2 January 14, 2017 Calapan City, Oriental Mindoro

Transcription

1 GIS: An Overview Mr. Mic Ivan V. Sumilang, EnP Senior Research Specialist Phil LiDAR 2 January 14, 2017 Calapan City, Oriental Mindoro 1

2 TOPICAL OUTLINE Definition of GIS History How does GIS work? GIS Data Types Projection Systems Data Sources Analyses Basic Map Elements Applications Available Software 2

3 DEFINITION OF GIS 3

4 What is GIS? A Geographic Information System or GIS is a computer system that allows you to map, model, query, and analyze large quantities of data within a single database according to their location. GIS gives you the power to: Create maps Integrate information Visualize scenarios Present powerful ideas, and Develop effective solutions (EPA, 2015) 4

5 What is GIS? GIS is a computer system capable of assembling, storing, manipulating, and displaying geographically referenced information (that is 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, 2007) 5

6 Components of GIS Software Hardware Data People Methods/Procedures (LSU, 2003) 6

7 Advantages of GIS 1. Cost Savings from Greater Efficiency 2. Improved Communication 3. Better Decision Making 4. Better Record Keeping 5. Managing Geographically (ESRI, n.d.) 7

8 General History of GIS 8

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10 The First Use of GIS 1854 Broad Street Cholera September 1854 (Centered in Soho district close to Snow s house) Mapped 13 public wells and all known deaths Noted the spatial clustering of cases around one particular water pump He examined water samples from various wells Halted the outbreak despite the authorities skepticism 10

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12 General History of GIS Difficult to chronicle due to the paucity of welldocumented evidence Computer-based GIS have been used by people since late 1960s. But, their manual predecessors started 100 years earlier. Development started in North America (USA and Canada) G r o w t h w a s p i e c e m e a l, s p o r a d i c, a n d uncoordinated. (Bato, 2010) 12

13 Organizations that started GIS 1. US Bureau of Census 2. US Geological Survey 3. Harvard Laboratory of Computer Graphics 4. Experimental Cartography Unit, UK 5. Environmental Systems Research Institute (ESRI) 6. Canada Geographic Information Systems (Bato, 2010) 13

14 Timeline of GIS Usage 1. Pioneering Age - early 1960s to individual personalities determined the course of GIS 2. Second Phase to the early 1980s - increase in experimentation and practice fostered by national agencies - duplication of efforts was common 3. Third Phase to late 1990s - commercial dominance 4. Fourth Phase (current) - user dominance - facilitated by competition among vendors - start of the standardization of GIS on open systems - Open GIS 14

15 What is fueling the development of GIS? 1. There exists a need to do things better and faster at the least possible cost. - land resources inventory, updating of maps, automated cartography, etc. 2. Development in computing technology from mainframes to powerful desktop computers 3. Commercial enterprises GIS is an enterprise, therefore, money matters. 4. Academe A significant number of people in the academe have shown interest in the Science of Geographic Information. Funding is available from grants and the Federal Government. 5. Federal Government The government needs to manage its resources properly, thus, need GIS in the process. 6. Users GIS is starting to become a publicly owned domain with the widespread use of Open Source solutions and publicly available mapping services. 15

16 History of GIS in the Philippines Started at the National Resource Management Center (NRMC) Image 100 Interactive Multispectral Image Analyzer System from the US was used in 1978 Arc/Info was introduced through the First Philippines GIS Workshop held in November 1982 (Bato, 2010) 16

17 History of GIS in the Philippines The Philippines-Australia RS Project started 1990, until 1994 Computerized Land Assessment and Planning System was introduced in 1974 by Synergistic Consultants, Inc., and is the country s first prototype GIS model (Bato, 2010) 17

18 Developments in Hardware and Software 1. Expensive mainframe computers to desktop-server environments 2. Expensive pen and thermal plotters to affordable inkjet and laser printers to a paperless environment 3. Digitizers to heads-up digitizing using scanned data from scanners to automated raster to vector conversion 4. Conventional surveys to surveys using GPS 5. Low to high accuracy GPS (Bato, 2010) 18

19 HOW DOES GIS WORK? 19

20 How does GIS work? ASK (What is the problem?) ACQUIRE (Find the data needed) EXAMINE (How the data is organized? Accurate? Where did it came from?) ANALYZE (Geographic analysis/core strength of GIS) ACT (Analysis can be shared through reports, maps, tables, and charts; delivered in printed format or digitally) (ESRI, n.d.) 20

21 How to represent geographic objects? Analog - Paper Maps Digital - Raster data model - Vector data model (Abucay, 2014) 21

22 GIS Data Types 22

23 GIS Data Types Vector Data Raster Data 23

24 GIS Data Types Vector data 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 (Stack Exchange, 2015). Advantages Representing continuous data (e.g., slope, elevation, chemical concentrations). Representing multiple feature types (e.g., points, lines, and polygons) as single feature types (cells). Rapid computations ("map algebra") in which raster layers are treated as elements in mathematical expressions. Analysis of multi-layer or multivariate data (e.g., satellite image processing and analysis) (Abucay, 2014) 24

25 GIS Data Types Raster data A representation of the world as a surface divided into a regular grid of cells. Raster models are useful for storing data that varies continuously, as in an aerial photograph, a satellite image, a surface of chemical concentrations, or an elevation surface (Stack Exchange, 2015). Advantages Accurately representing true shape and size. Representing noncontinuous data (e.g. rivers, political boundaries, road lines, mountain peaks). Creating aesthetically pleasing maps. Conserving disk space (Abucay, 2014) 25

26 GIS Data Types 26

27 Projection Systems 27

28 SPHERE GEOID SPHEROID/ELLIPSOID 28

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30 Longitude The angular distance, usually expressed in degrees, minutes, and seconds, of a location of a point on the earth s surface, east or west of an arbitrarily defined meridian (usually the Greenwich prime meridian). All lines of longitude are great circles that intersect the equator and pass through the North and South Poles. (ESRI) Latitude - The angular distance, usually measured in degrees, north or south of the equator. Lines of latitude are also referred to as parallels. (ESRI) 30

31 Equator - The parallel of reference that is equidistant from the poles and defines the origin of the latitude values. (ESRI) Prime meridian Any line of longitude designated as 0 degrees east and west, to which all other meridians are referenced. (ESRI) Greenwich prime meridian - 0 degrees longitude, passes through the Royal Observatory, Greenwich, England Adopted by international agreement in 1884 as the prime meridian 31

32 Three types of coordinate systems Spherical Spheroidal Cartesian 32

33 Geographic Coordinate System VS Projected Coordinate System 33

34 Geographic Coordinate System data that is defined by a 3-D surface and measured in latitude and longitude An example of a Geographic Coordinate System would be "WGS 1984 the term "Datum" and "Geograhpic Coordinate System" can be used interchangeably (ESRI, 2011) 34

35 Projected Coordinate System Data that is defined by a flat 2-D surface and can be measured in units of meters and feet "Map projections" and "Projected Coordinate Systems" can be used interchangably as well. (ESRI, 2011) 35

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38 General Categories of Projection Systems Cylindrical Projection Azimuthal Projection Conic Projection 38

39 General Categories of Projection Systems Cylindrical Projection A. Cylindrical Equidistant Projection B. Cylindrical Equal Area Projection C. Mercator Projection D. Transverse Mercator Projection E. Oblique Mercator Projection 39

40 General Categories of Projection Systems Azimuthal Projection A. General Azimuthal Projection B. Azimuthal Equidistant Projection C. Azimuthal Equal Area Projection D. Azimuthal Stereographic (Conformal) Projection E. Gnomic Projection 40

41 General Categories of Projection Systems Conic projection A. General Conic Projection B. Conic Equidistant Projection C. Albers (Conic) Equal Area Projection D. Lambert Conformal Conic Projection 41

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43 Projection systems being used in the Philippines 1. Transverse Mercator Projection (Luzon 1911Datum) 2. Philippines Transverse Mercator Projection (also based on the Luzon 1911 Datum) 3. Philippine Reference System 1992 (PRS92) - based on WGS not yet finished 4. Universal Transverse Mercator Projection (UTM) WGS84 Datum 5. WGS84 or WGS 1984 (World Geodetic System 1984) 43

44 (Bato, 2010) 44

45 (Bato, 2010) 45

46 Data Sources 46

47 DATA SOURCES GPS (Global Positioning System) Digitized Images Scanned Maps Remotely Sensed Data Geocoding and Metadata 47

48 DATA SOURCES 48

49 Sources of Information LGU NAMRIA PHIVOLCS BSWM DA-BAR MGB 49

50 LGU Local Government Unit Cluster Map Establishment Map (Infrastructures) Existing Land Use Map Garbage Disposal Map Land Management Unit Map Population Map River Easements Map River Systems Map Road Map SAFDZ Map Suitability Map (Coconut, Rice, and other Fruits) 50

51 NAMRIA National Mapping and Resource Information Authority Contour Map Land Cover Map Topographic Map 51

52 PHIVOLCS Philippine Institute of Volcanology and Seismology Earthquake Landslide Susceptibility Map Land Cover Map Fault line Map Landslide Pyroclastic Volcanic Hazard Volcanic Hazard Map 52

53 BSWM Bureau of Soils and Water Management Agrohydrological Map Flood Map Geologic Map Infiltration Map Pasture Livestock Map Permeability Map Soil Erosion Map 53

54 DA-BAR Department of Agriculture's Bureau of Agricultural Research Land Classification Map NIPAS NPAAAD Soil Geo Map Soil Tax Map Soil Type Map Watershed Map 54

55 MGB Mines and Geosciences Bureau Landslide and Flood Susceptibility Map 55

56 ANALYSIS 56

57 ANALYSIS Queries Geoprocessing Spatial Analysis (Buffers/Raster Calculator) Interpolation/Spatial Modeling Terrain and 3D Mapping 57

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67 Basic Map Elements 67

68 Do you think this is a MAP? 68

69 Basic Map Elements 1. Title 2. Legend 3. North Arrow 4. Scale Bar 5. Scale text 6. Data Source 7. Coordinate System 69

70 APPLICATIONS 70

71 Applications 1. Land Use Planning 2. Hazard Mapping 3. Resources Inventory/Management 4. Pre/Post Disaster Assessment 5. Flood Modeling 6. Infrastructure Planning and Development 7. Tourism 8. Tax Mapping 71

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75 (Bragais 2015) 75

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79 Available Software for GIS 79

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81 References Abucay, E. R. (2014). Mapping with ArcGIS. Bato, V. A. (2010). Introduction to GIS: History, Applications, and Components of GIS. EPA. (2015, February 3). Retrieved from United States Environmental Protection Agency : ESRI. (n.d.). Retrieved from esri.com: ESRI. (2011, March 1). Retrieved from LSU. (2003, February 21). Retrieved from Luisiana Geographic Information Center : Stack Exchange. (2015). Retrieved from Stack Exchange : /questions/57142/what-is-the-difference-between-vector-and-raster-data-models USGS. (2007, February 14). Retrieved from USGS: Science for a changing world: 81

82 THANK YOU! 82