Data Gathering & Technologies (College Board AP® Human Geography): Study Guide

Data gathering

Sources of geographic data

• Geographers gather geographic data from a wide range of sources

• Field-based sources collect information directly from a place:

  • Field observation and landscape analysis, both covered in detail below

  • Personal interviews — asking people directly about a place and how they experience it

• Written and media sources record what others have already observed:

  • Media reports — news coverage and journalism about a place or an event

  • Travel narratives — written accounts by people who have visited a place

  • Policy documents — government plans, legislation and planning records

• Visual and digital sources present spatial information to be interpreted:

  • Photographic interpretation — analyzing aerial, satellite or ground-level photographs

  • Online mapping and visualization — interactive maps, dashboards and charts that display spatial data

• Data from any of these sources is either qualitative or quantitative:

  • Qualitative data is descriptive or opinion-based and is not expressed in numbers

    • Interviews, written descriptions and opinion surveys are qualitative

  • Quantitative data can be measured and recorded in numbers

    • Population, temperature and average income are quantitative

• Landscape Analysis is the process of studying and describing the landscape of a place to assess the impact of humans on the environment 

• Geographers use field observation to conduct landscape analysis

• Field observation involves:

  •  Physically traveling to a place

  • Recording details and observations about the place

• Spatial data records information about the physical location of objects in a place 

• The built environment refers to the physical artifacts created by humans that form part of the landscape

  • Built environments are unique across cultures and reflect unique characteristics

• The cultural landscape includes structures and changes within the physical landscape that reflect human activity

  • The cultural landscape communicates information about the:

    • culture

    • economy

    • language

    • religion

  • It is about human society in a place

Geospatial technologies

• Geographers use multiple technologies to collect, analyze and graph spatial data

• These geographic technologies include:

  • Geographic Information Systems (GIS)

  • remote sensing

  • Satellite Navigation Systems

• Geographic Information Systems (GIS) display spatial data in layered maps

• GIS stores spatial data in two different formats:

  • Vector data represents features as points, lines and polygons

    • A city is a point, a road is a line, and a county is a polygon

    • Vector data keeps sharp, exact edges at any zoom level, so it suits boundaries, road networks and other clearly defined features

  • Raster data represents an area as a grid of cells, with each cell holding a single value

    • A satellite image is raster data — every pixel records a value such as land cover or surface temperature

    • Raster data suits information that changes gradually across space, such as elevation or rainfall

• The format matters because it decides what kind of analysis is possible

  • Vector data is better for measuring distances and areas

  • Raster data is better for comparing conditions across a whole surface

• Remote sensing gathers photographic data from a distance, usually using satellite or aerial photographs

• Satellite Navigation Systems provide precise locations using triangulation

  • Global Positioning System (GPS) maps are an example of a satellite navigation system

Uses of geospatial technologies

• Urban planning

  • Planners use GIS to map land use, zoning, transport routes and how far services reach

  • Layering population data over service coverage shows where new schools or clinics are needed

• Disaster response

  • Remote sensing tracks hurricanes, floods and wildfires as they happen

  • Comparing satellite images from before and after an event shows responders which areas are worst hit, so aid can be routed there first

• Agriculture

  • GPS-guided machinery and satellite data make precision agriculture possible

  • Water, fertilizer and pesticide are applied only to the parts of a field that need them, which cuts cost and runoff

• Military and security

  • GPS is used for navigation, positioning and targeting

  • Satellite imagery is used to monitor borders, shipping and troop movements

• Everyday life

  • Satellite navigation apps give turn-by-turn driving directions and live traffic updates

  • Ride-hailing and food delivery services match users to the nearest driver

  • Phones tag photographs with the location they were taken