1 / 28

The Meaning of Geographic Expressions

The Meaning of Geographic Expressions. Dr Kristin Stock kristin.stock@nottingham.ac.uk. Q. These houses look like:. Comfortable homes A retirement village A slum Mansions. Q. I would describe this geographic feature as:. A hill An island A volcano A cay.

kristina
Download Presentation

The Meaning of Geographic Expressions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Meaning of Geographic Expressions Dr Kristin Stock kristin.stock@nottingham.ac.uk

  2. Q. These houses look like: Comfortable homes A retirement village A slum Mansions

  3. Q. I would describe this geographic feature as: A hill An island A volcano A cay

  4. Little round planetIn a big universeSometimes it looks blessedSometimes it looks cursedDepends on what you look at obviouslyBut even more it depends on the way that you seeBruce Cockburn

  5. What does it all mean?

  6. How Do People Think? How Do Computers Think?

  7. Bridging the gap...

  8. What is a geographic expression? • National Parks near Nottingham. • Walking paths in the Peak District. • The river is opposite the museum. • The library is around the corner from the market square. • The castle is near here. • Which rivers go through the Lake District? • Which mountains in the Alps are steep? • Where is a large lake near Nottingham?

  9. Geographic Expressions aremade up of... • Geographic Features • Spatial Relations • Geographic Qualifiers

  10. Geographic Features • Objects that have a location relative to the earth. • Natural, person-made or administrative. • Categories or instances (instance = a specific object). • Usually nouns in English.

  11. Spatial Relations • Words that describe the relationship in space between two features. • Usually verbs in English. intersects touches on covers near contains crosses in next to

  12. Geographic Qualifiers • Further restrict or qualify a geographic feature. • Sometimes vague in interpretation. • Usually adjectives in English.

  13. Q. The parts of these expressions shown in red are: • National Parks near Nottingham. • Walkingpaths in the Peak District. • The river is opposite the museum. • The library is around the corner from the marketsquare. • Is the castle near here? • Which rivers go through the Lake District? • Which mountains in the Alps are steep? • Where is a large lake near Nottingham? • Geographic object categories • Geographic object instances • Spatial relations • Geographic qualifiers

  14. Q. An example of a spatial relation is: • around the corner • go through • tallest • Nottingham • River • step-mother

  15. Q. ‘large’ is: • A geographic object category • A spatial relation • A geographic qualifier • A geographic object instance • An administrative relation

  16. Spatial Relations Exercise

  17. Q. I would describe this geographic feature as a: • Creek • Beck • River • Stream • Road

  18. Q. I would describe this geographic feature as a: • Hill • Hillock • Mountain • Tor • Munro • Pingo

  19. How do the meanings of geographic expressions vary? • Culture. • Background. • Education. • Environment. • Context (dynamic).

  20. So, how do people think about geographic features? • Differently from each other (to varying degrees). • Sometimes vaguely. • Sometimes context sensitively.

  21. But, how do computers think about geographic information?

  22. Geographic Expressions • Have a precise, fixed meaning: • The same for everyone; • Not context sensitive; • Not vague. • Have rigid, crisp (not fuzzy) physical boundaries.

  23. Geographic Features • Census output area polygons, lower level super-output area polygons, ward polygons. • County polygons. • National Park polygons. • Road network. • Buildings from Historical Digimap.

  24. Spatial Relations • Query operators allowed by ArcMap: • Intersect • Completely contain • Share a line segment with • Touch the boundary of • Have their centroid in • Like geographic features, spatial operators in GIS are also crisp and rigid.

  25. Q. Which spatial operator would you use to: ‘find the buildings in Smith Street?’ • Contains • Crosses • Overlaps • Touches • Within • Near

  26. Geographic Qualifiers Q. How would you query geographic qualifiers(steep, large) in a GIS? • I would look for an attribute containing the relevant information. • I would look at the spatial relations to try to deduce the qualifier values. • I would ask the person next to me. • I wouldn’t.

  27. Summary • People think uniquely, context-sensitively, sometimes vaguely. • Computers think precisely, crisply, uniformly. • When using current mainstream GIS, people have to bridge the gap. • We are working on ways to help computers bridge the gap...

More Related