Module 2

• Map


  • Any picture, drawing or group of objects that helps somebody understand a place
  • A scaled model or reality
  • It contains geographic and spatial information
  • A tool for analysis of spatial relationships
• Cave paintings


  • Mapped records of ambush areas for ancient hunters
• Basic community sketch maps

  • Depict physical spatial elements from the community's point of view in 2D
• Elements of a Map

  • Scale and Distance
  • Direction
  • Location
  • Symbols
  • Type of map
• Scale


  • The relationship between a unit of length on a map and the corresponding length on the ground
  • Usually expressed in a ratio (e.g. 1:100)
• Distance


  • Measurement of how far one point is to another
  • Ground distance can be determined in the map through scale
• Location


  • The physical place where a point is found on the Earth's surface
  • Can be expressed as absolute location using coordinates (e.g. Latitude = 14°9'48" Longitude = 121°14'21")
  • Can also be expressed as relative location (e.g. 3 km northwest of CHE building)
• Coordinates


  Pair of numbers that describe a location usually expressed in Degrees, Minutes, Seconds (DMS) format
• Symbols


  Legend in the map guides the reader what each symbol, pattern, and line means
• Type of Map


  The three fields that focus on mapping: Cartography, Geography, Geodesy
• Cartography


  The art and science of graphically representing a geographical area, usually on a flat surface such as a map or chart
• Geography


  The study of the Earth and its lands, features, inhabitants and phenomena
• Geodesy


  The science of accurately measuring and understanding the Earth's geometric shape, orientation in space, and gravity field
• Datum


  A known constant surface which can be used to describe the location of unknown points
• WGS 84


  Universally used reference datum which is comprised of a reference ellipsoid, standard coordinate system, vertical datum (elevation), and horizontal datum
• Luzon Datum 1911


  Reference system for the first modern geodetic survey in the Philippines, datum origin in Balanacan, Mogpog, Marinduque
• Philippine Reference System 1992 (PRS92)


  A homogenous national network of geodetic control points (GCP), marked by concrete monuments (mojons), established using GPS technology, adopted as the standard reference for all surveying and mapping activities in the country
• Coordinate Systems


  • Geographic Coordinate Systems
  • Projected Coordinate Systems
• Geographic Coordinate Systems


  Uses a 3-dimensional spherical surface to define locations on the earth, a point is referenced by its longitude (x values) and latitude (y values) which are measured in angular degrees
• Projected Coordinate Systems


  Defined on a flat, 2-dimensional surface which has constant lengths, angles, and areas, always based on a geographic coordinate system (GCS) which is based on a sphere or spheroid
• Map Projection


  A system which gives the relation between the position of a point on Earth and that of the same point on a map, aims to transform a part of the Earth's surface from a globe onto a plane, at the same time keeping distortions in shape, area, and distance as small as possible
• Transverse Mercator


  Direction and shapes are correct, capable of mapping a large extent of North-South region with a low amount of distortion, most widely used is the Universal Transverse Mercator (UTM)
• Universal Transverse Mercator (UTM)


  Allows precise measurements using meter as a basic unit of measure, universally accepted by many countries and by the scientific community, adopted in much of remote sensing, topographic map preparations, and natural resources database development
• Spatial data collection and utilization methodologies

  • Surveying
  • Remote sensing
  • Global positioning system (GPS)
  • Digital Globes
  • Volunteered geographic information (VGI)/ Participatory mapping
  • Geographic information systems (GIS)
• Surveying


  The science of accurate measurement of natural and human-made features on the Earth, data collected by surveyors are then used to create highly precise maps
• Remote Sensing


  The science of obtaining information about objects or areas from a distance, typically from satellites or aircrafts, and now, drones
• Global positioning system (GPS)


  A satellite network that communicates with GPS receivers accessed by mobile users, the GPS receiver needs to connect with four or more satellites orbiting the Earth, as reference to calculate the precise location of the user
• Digital globes


  1. dimensional representations of the Earth in high-resolution format, the aim is to reduce distortion and reveal spatial relationships between places, highly interactive and dynamic
• VGI and Participatory GIS

  Volunteered geographic information (VGI) is the harnessing of tools to create, assemble, and disseminate geographic data provided voluntarily by individuals, allows people to have a more active role in activities such as urban planning and mapping
• Geographic Information System (GIS)


  A computer system used by people capable of assembling, storing, manipulating and displaying geographically referenced information, integrates common database operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps
• Geographic Information Science


  The field of research that studies the theory and concepts that underpin GIS, seeks to establish a theoretical basis for the technology and use of GIS, how concepts from cognitive science and information science apply to GIS and investigates how GIS interacts with society
• Cro-Magnon hunters drew pictures of the animals they hunted on the walls of caves near Lascaux, France


  35,000 years ago
• These early records followed the two-element structure of modern GIS: a graphic file linked to an attribute database
• John Snow traced the source of cholera outbreak in London, considered the first epidemiological analysis of disease outbreak using spatial analysis


  1854
• Many of GIS's origin came from the military particularly in the US
• Computerized handling of geographical information originated from two largely independent organizations: Harvard laboratory for computer graphics and Canadian GIS (CGIS)


  Early 1960s
• Roger Tomlinson, an English geographer, coined the term "geographic information system (GIS)" and is considered the "Father of GIS"
• Phases of GIS through time

  • 1970s: Increasing computing power and awareness of the importance of environmental issues spurred the growth of GIS
  • 1980s: Launch of ArcInfo, the GIS software package that was to become the industry standard for the next two decades
  • 1990s: Increasing availability and power of desktop personal computers (PCs) led to the launch of new software that can run on PCs with user-friendly graphical user interfaces (GUI)
• How does GIS work?

  • Input: Before geographic data can be used in GIS, it must be converted into a suitable digital format
  • Manipulation: GIS software allows users to perform various operations on the data, such as querying, analyzing, and visualizing
  • Output: The results of GIS analysis can be displayed in the form of maps, reports, or other visualizations
• The emergence of environmental issues spurred the growth of GIS