GIS T1

Introduction to GIS

 Week 1 Readings & Lecture

1. Formally, define and describe GIS?

   • Geographic Information System (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present spatial or geographic data.

2. What is spatial data and how does it differ from attribute data?

   • Spatial data represents the location, shape, and size of features on the Earth’s surface, while attribute data provides descriptive information about those features.

3. What are some strengths of a GIS? How does it help us understand the world?

   • GIS strengths include spatial analysis, data visualization, and integration of different data types, helping to reveal patterns, relationships, and trends in the environment.

4. What is Tobler’s 1st law? Give some examples.

   • Tobler’s 1st Law states: "Everything is related to everything else, but near things are more related than distant things." Example: Temperature readings in neighboring cities are more similar than cities farther apart.

5. Describe two ways GIS is used in the real world.

   • Urban planning: Analyzing land use and infrastructure.

   • Environmental monitoring: Tracking deforestation or pollution levels.

Week 2 Readings & Lectures

1. What are spatial data models?

   • Spatial data models are frameworks that represent geographic features and their relationships.

2. Why do we use spatial data models?

   • To organize, store, and manipulate spatial data efficiently.

3. What is the vector data model?

   • A model representing geographic features through points, lines, and polygons.

4. How are attributes stored in the vector data model?

   • In tables where each row represents a feature and columns represent attributes.

5. How does the map scale affect the representation of spatial features on a map?

   • Larger scales show more detail, while smaller scales show less detail.

6. What is topology and what role does topology play in vector data?

   • Topology defines spatial relationships between features, such as adjacency and connectivity, ensuring data integrity.

7. What is a shapefile?

   • A common vector data format that stores geometric location and attribute information.

8. What is a geodatabase?

   • A database designed to store, query, and manage spatial data.

9. What are some open-source file formats commonly used in GIS?

   • GeoJSON, KML, and GPKG.

10. What is a feature class?

    • A collection of geographic features with the same geometry type and attributes.

11. What are several key qualities that make geodatabases flexible enough to manage any GIS project?

    • Versioning, topology rules, and relationship classes.

12. What is the raster data model?

    • A model representing geographic features as a grid of cells.

13. How are attributes stored in a raster data model?

    • Each cell holds a single value representing a measured attribute.

14. What is cell size and how does it influence spatial resolution?

    • Smaller cell sizes provide higher resolution and more detail.

15. How are raster datasets georeferenced?

    • By linking the grid cells to geographic coordinates using coordinate reference systems.

Week 3 Readings & Lectures

1. What is metadata and why is it important?

   • Metadata describes the content, quality, and source of spatial data, ensuring proper usage and interpretation.

2. What is a coordinate system?

   • A system that uses numbers to define locations on the Earth’s surface.

3. What is a geographic coordinate system?

   • A system that uses latitude and longitude to define locations.

4. What is latitude?

   • The angular distance north or south of the equator.

5. What is longitude?

   • The angular distance east or west of the Prime Meridian.

6. What happens to the distances between lines of longitude as you move across the globe?

   • They converge towards the poles.

7. How does one conceptualization of the shape of the Earth impact our location and measurements?

   • Different models (sphere, ellipsoid) affect distance and area calculations.

8. What is the shape of the Earth?

   • An oblate spheroid.

9. What is an ellipsoid/spheroid and why are there so many of them used in GIS?

   • A mathematical model approximating the Earth’s shape; different regions use different ellipsoids to improve accuracy.

10. What are a datum and an ellipsoid?

    • A datum defines the origin and orientation of coordinates, while an ellipsoid approximates the Earth's shape.

11. What are the common datums underlying the US?

    • NAD27, NAD83, and WGS84.

12. What problems arise from the use of different datums?

    • Coordinate discrepancies between maps based on different datums.

13. What is a map projection?

    • A method of representing the 3D Earth on a 2D surface.

14. What types of distortions do projections create?

    • Shape, area, distance, and direction.

15. What is the importance of map projections?

    • They enable accurate geographic data visualization and analysis.

16. How do geodatabases store information about coordinate systems?

    • Through metadata and spatial reference properties.

17. What is UTM?

    • Universal Transverse Mercator, a coordinate system dividing the globe into zones for detailed mapping.

18. What is a state plane coordinate system?

    • A system dividing the US into zones with high-accuracy mapping.

19. What factors might one think through when determining which map projection to use?

    • Purpose, area size, and type of distortion to minimize.

Week 4 Readings & Lectures

1. What is a database?

   • A structured collection of data.

2. What is a database management system (DBMS) and what advantages do they provide for managing data?

   • Software that organizes, manages, and retrieves data efficiently.

3. What are a type and domain?

   • Type defines data format; domain sets allowable attribute values.

4. What is a relational database?

   • A database structured to recognize relations among stored data.

5. What is an attribute query (select by attribute)?

   • A search for features based on their attribute values.

6. What is a locational/spatial query (select by location)?

   • A search for features based on their geographic location.

7. What is SQL and how is it used?

   • Structured Query Language for querying and managing databases.

8. What is an attribute join and when would you use it?

   • Combines two tables based on a common field to merge attributes.

9. What is a spatial join and when would you use it?

   • Combines attributes of two layers based on spatial relationships.

10. What is the difference between a join and a relate?

    • Join merges tables, relate links tables without merging.

Week 5

1.     Factors to Consider Before Making a Map:

o   Purpose of the map (what story or information it conveys)

o   Audience (who will be using the map)

o   Data availability and quality

o   Scale and projection type

o   Design constraints (size, color limitations, printing format)

2.     Mandatory/Primary Map Elements:

o   Title: Provides the map’s purpose or subject.

o   Legend: Explains symbols, colors, and patterns used on the map.

o   Scale Bar: Indicates the relationship between map distance and real-world distance.

o   North Arrow: Shows map orientation.

o   Data Source/Citation: Acknowledges the source of data and any authorship.

3.     Brewer’s 3 Essentials for Better Maps:

o   Clarity: Clear visual representation of data.

o   Balance: Proper layout of map elements.

o   Hierarchy: Emphasizing the most important information.

4.     Field’s 5 Things for Thematic Maps:

o   Simplicity: Avoid clutter.

o   Legibility: Easy to read symbols and text.

o   Harmony: Consistent design choices.

o   Accuracy: Correct and honest representation of data.

o   Storytelling: Effectively conveying the intended message.

5.     Five Habits for Critical Map Reading:

o   Question the map’s purpose.

o   Identify what’s included and excluded.

o   Assess the data source.

o   Analyze the map’s design choices.

o   Consider the map’s message or bias.

6.     Visual Hierarchy:

o   Organizing elements based on importance.

o   Achieved through size, color, contrast, and placement.

7.     Visual Balance:

o   Distribution of visual elements to create a pleasing layout.

o   Balances dense and sparse areas, color usage, and element positioning.

8.     Figure-Ground Concept:

o   Distinguishes between the focal subject (figure) and background (ground).

o   Enhances clarity and readability.

9.     Serif vs. Sans Serif Type Families:

o   Serif: Fonts with small decorative lines (e.g., Times New Roman) – used for printed materials.

o   Sans Serif: Fonts without decorative lines (e.g., Arial) – often used for digital displays.

10.  Typography’s Role in Visual Hierarchy:

o   Differentiates importance through font size, weight, and style.

o   Helps guide the reader’s eye to key information.

11.  Role of Labels in Mapping:

o   Identifies features.

o   Provides context to symbols and areas.

o   Enhances map readability.

12.  Label Placement Guidelines:

o   Areas: Curved or horizontal along feature shape.

o   Lines: Parallel or above the line.

o   Points: Above, to the right, or centered if space allows.

Week 6

1.     Buckley and Field’s Map Evaluation:

o   They would assess clarity, design quality, and how well the map conveys its story.

2.     Buckley’s Five Design Principles:

o   Simplicity: Avoid unnecessary complexity.

o   Clarity: Clear presentation.

o   Balance: Harmonious layout.

o   Consistency: Uniform design choices.

o   Accessibility: Inclusive for all users.

3.     Improving Map Clarity for Color Vision Impaired:

o   Use colorblind-friendly palettes.

o   Add patterns or textures.

o   Include labels and symbols alongside color.

4.     Importance of Color Vision Impairment Considerations:

o   Ensures inclusivity.

o   Improves overall map readability.

o   Broadens the map’s accessibility.

5.     Choropleth/Graduated Color Map:

o   Strengths: Easy to interpret, shows patterns.

o   Weaknesses: Can imply abrupt changes between areas.

6.     Graduated Symbol/Proportional Symbol Map:

o   Strengths: Good for quantitative data.

o   Weaknesses: Can become cluttered.

7.     Dot Density Map:

o   Strengths: Shows distribution patterns.

o   Weaknesses: Can be misleading if not scaled properly.

8.     Data Classification Methods:

o   Equal Interval: Divides data into equal ranges.

o   Quantile: Equal number of features in each class.

o   Natural Breaks: Groups data based on clusters and gaps.

9.     Impact of Data Classification:

o   Affects the visual message.

o   Can exaggerate or minimize trends.

o   Influences map interpretation.

10.  Choosing Classification Method:

o   Based on data distribution.

o   Purpose of the map.

o   Audience needs.