Intro to Geographic Information Systems (GIS)

Key Concepts & Definitions

Overview of GIS and Related Technologies

• GIS (Geographic Information System): A system designed to capture, store, manage, analyze, and visualize location-based data, enabling users to understand spatial relationships and patterns.

• Geospatial Technology: Encompasses high-tech tools for managing geographic data, including GIS, Remote Sensing, and GPS, facilitating advanced data analysis and visualization.

• Remote Sensing: The process of collecting data about the Earth's surface without direct contact, utilizing satellites, aircraft, or drones to gather information on various environmental factors.

• Global Positioning System (GPS): A satellite-based system that provides real-time location data, crucial for navigation and mapping applications.

• GNSS (Global Navigation Satellite Systems): A broader category that includes various satellite-based positioning systems, with GPS being a prominent example.

GIS as an Abstraction of Reality

• GIS simplifies complex real-world phenomena into manageable data models, allowing for effective analysis and decision-making.

• It aids in understanding spatial relationships and trends, which can be critical for urban planning, environmental monitoring, and resource management.

Applications of GIS

Diverse Applications Across Sectors

• Entertainment: GIS is used in video game development to create realistic landscapes and immersive environments for players.

• Environmental Monitoring: GIS tools track air quality trends, helping to identify pollution sources and assess environmental health.

• Urban Planning: GIS assists in analyzing flood risks, optimizing land use, and planning infrastructure development.

• Transportation: GIS is essential for mapping transportation networks, including roads, railroads, and airports, enhancing logistics and travel efficiency.

Types of Data in GIS

Spatial vs. Non-Spatial Data

• Spatial Data: This includes information about the location, spatial extent, and characteristics of geographic features, such as roads, mountains, and rivers.

• Non-Spatial Data: Descriptive data that is not tied to a specific location, such as demographic statistics or housing prices, which can be linked to spatial data for analysis.

Determining Spatial vs. Non-Spatial Data

• Example of Spatial Data: The length of a river, which has a specific location on Earth.

• Example of Non-Spatial Data: The width of a table, which is not inherently tied to a geographic location unless contextualized (e.g., a café's table width).

Sources of Geospatial Data

Key Data Sources

• Giovanni (NASA): Provides climate-related data, including precipitation, temperature, and forest coverage, useful for environmental studies.

• The National Map (USGS): Offers comprehensive data on elevation, hydrography, transportation, and land cover, essential for various GIS applications.

• Earth Explorer (USGS): A platform for accessing Landsat satellite imagery, which is vital for land use and environmental monitoring.

• Census Data: Contains demographic and movement statistics, providing insights into population dynamics and trends.

• TIGER Data (US Census Bureau): Supplies detailed street, road, and boundary data, crucial for urban planning and navigation.

Citizen Science & Crowdsourced Geospatial Data

Volunteered Geographic Information (VGI)

• VGI: Refers to user-generated mapping data, such as contributions to OpenStreetMap and Google Maps, which enhance geographic databases.

• Crowdsourcing Examples:

1. USGS "Did You Feel It?": A platform for collecting earthquake reports from the public, aiding in real-time data collection and analysis.

2. Map Kibera: A community-driven mapping initiative in Kenya that empowers local residents to document their environment and resources.

Geolocation & Related Technologies

Understanding Geolocation

• Geolocation: The process of determining an object's real-world location using smart devices, which is essential for various applications, including navigation and location-based services.

• W3C Geolocation API: A standard for retrieving location data online, enabling developers to integrate geolocation features into web applications.

• Geotagging: The practice of linking real-world locations to digital items, such as social media posts, enhancing the context and relevance of online content.

Accuracy & Geolocation Challenges

Challenges in Geolocation

• False Positives in Geolocation: Occurs when location data is misinterpreted based on content, leading to inaccuracies in mapping and analysis.

• Heat Maps: Visual representations of geotagged activities, such as tracking social media trends after significant events, providing insights into public engagement and behavior.