Ch 2: GIS, Human Geography, and the Intellectual Territory Between Them

• GIS systems and science are based on assumptions that privilege certain approaches to understanding the world (natural and human)

• The relationship between human geography and GIS is important in the development of GIS technology and applications as well as the discipline of geography

• Geography began as a loose collection of scientist and empiricists interested in the physical nature of the earth’s surface as well as the role of constructing politics and behaviors

• GIS since the late 1960’s, parts of cartography and quantitative methods

A rocky relationship between these and geography in general

Mind the Gap: The Distance Between Human Geography and GIS

• GIS and human geography occupied separate spheres of geography until the late 1980’s

• Geographers critique early on is more technique and not an intellectual component

• GIS processes facts, but can’t generate meaningful understanding

• GIS is controlled by computer science

• The development of GIS in geography has lead to the realization that databases and spatial analysis are subject to uncertainty and can be inaccurate

• GIS based on positivism and naïve empiricism

• Lots of discussion on GIS in the 1980’s

• GIS people had more of a scientific approach then human geographers who were more qualitative and social theories

• GIS very limited view of the world, only people who had access to the expensive software were able to answer vague questions

• GIS driven by corporate and military needs / Very expensive

• Harley’s late ground breaking work on relationship between maps and power shaped GIS

• Harley said that maps have always been a mechanism for depicting and producing social relations

• A map is not a neutral representation of territory, but a representation of social relations

• Maps create space of political territories and privately owned property and make those human conceptions real in the landscape

• Friday Harbor meetings began the dialog of GIS / Gave guidelines to GIS

Epistemology and Ontology in GIS

<!–[if !supportLists]–>§         <!–[endif]–>Epistemology- the methods use to study the world; each has assumptions and perspectives that shape the questions, analysis, and interpretation of results

<!–[if !supportLists]–>§         <!–[endif]–>Ontology- what things really are (how the world must be to make sense of it)

<!–[if !supportLists]–>§         <!–[endif]–>Ex. GIS technology to determine the quickest routes for personal travel (GPS unit for your car)

Data Models and Ontology

Ontology : a formally defined set of objects in which all the potential relationships between the objects are also well defined.

• to represent these objects in a GIS requires a method of encoding them digitally as entities, and then encoding the relationships between them

Data Models: ways of imagining space – in order to render it in a computational environment.

Vector Data Model: point, line, area (necessary to encode data into the GIS); most ubiquitous; most resembles traditional maps.

Polygons are synonymous with areas; three-dimensional surfaces are built from areas.

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Example: People: US census blocks

• define area as a particular amount of people, count number of people
• all space filled with blocks

Raster Data Models: divide the world into a sequence of identical, discrete entities, by imposing a regular grid. Usually, the grid is square.

• land use: can be very defined, each cell assigned a type of land use based on energy reflected from it.
• complex mosaic of land use often generalized into commercial, agricultural, etc.
• all space has some kind of land use
• there may be hundreds of attribute layers for one geographic area, but each attribute layer includes the same grid cells, and each contains a single value for each attribute

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Object Oriented Data Models: alternative to the vision of the world as a series of locationally registered layers, each representing a single attribute.

• group together similar objects (roads) and have subclasses (federal,state, local)
• hierarchical: each parent object have attributes common to its subclasses
• allow for empty space as well as overlapping objects
  • can also be defined by function or process rather than name

• all data models are reductionist: they simplify complex reality

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The “Social” in GIS

•  recognition that science is part and parcel of our cultural fabric, rather than an objective lens on reality
  • ex. funding and research on health biased towards white males

Technology is developed for social problems, and in tandem with social goals

• GIS: influenced by both cultural and technical factors
• social dimension to every digital decision
• Generalization:  the elimination of map detail as scale decreases
  • ex. scale at 1:2,500 ofa city block includes sidewalks and alleyways; scale at 1:10,000 sidewalks are eliminated. At 1:50,000 only urban area transected by roads and freeways would remain.
  • ex. technical products are shaped by prevailing ways of thinking about a problem
• Reduction of Detail: effected by different mechanisms including aggregation of features, simplification of symbology, and removal of spatial entities

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GIS: technology

Geographic Information Systems are growing rapidly as a method used by diverse people for diverse applications

Use is growing faster than the real understanding of assumptions and limits of the concept

- More conceptual, theoretical, philosophical issues

GIScience Theory:

Patterns of development:

1. Economic pressures bear on the way that solutions to problems are resolved.

2. The way in which a problem has been envisaged has bearing on how GIScientists work to resolve the problem.

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Schuurman pages 53-71

• Data -  Most important factor in GIS analysis
  • “Analysis is only as persuasive as the data that underlie it.”
    • Without good data analysis is inaccurate.
  • Express the point of view and agenda of the person who is creating the map. 
    • Can be easily manipulated to show different trends
    • “…begin as observations, and are transformed into numbers in data tables that provide the basis for spatial analysis.

How is data collected?

• Census Data
  • Used to collect data about humans.
  • Often times problems arise with census collection
    • The trends of the population are not always accurately portrayed through the data due to undercount. 
    • “Homeless people, the disenfranchised, and people who are suspicious of government intervention are among those who may not be counted.”
  • Arguments between political parties
    • Census counts determine allocation of money and voting districts that may favor one party over another. 
    • People who are undercounted are likely to be democratic voters.
    • Democrats argue statistical sampling would be the most accurate.
      • Opposed based on the constitution that states the census will be the data used

• Field Data
  • Data collected by physical geographers based on “known ground control points such as weather stations for which latitude and longitude are available.”
  • GPS “global positioning system” is used to collect data at very accurate locations
    • Based on 24 NAVSTAR satellites that circle the earth non-stop. 
    • Need 3 satellites to triangulate the exact location which is measured by “how long it took (the signal from space) to reach the earth.”
    • The more satellite signals that are received the better the accuracy of the GPS coordinates.
  • Two types of data
    • Primary – collected by you
    • Secondary – use data previously collected

How is data organized?

• Organized in tables:
  • Location:  spatial data, where the data was collected (coordinate systems)
  • Attributable data:  descried the data collected at a specific location
    • Give data attributes
  • Consistency:  no gaps or missing data
    • “Consistency is the key to good data, and good data is the key to reliable analysis.”
  • Scale:  Measures what a given measurement on a map corresponds to on the ground.
    • Needs to be consistent
  • Data interpolation:  filling in values of data between known data points.

Metadata

• Need to know information about data (data about data)
  • Important to know the scale, what year data was collected, who collected the data if using a secondary data source.
  • Important to know so one can assess the reliability of the data.

Interoperability

• The ability to use data across a wide range of software.
  • Ex) .txt or .jpeg files can be opened using a range of programs
  • Data that is interoperable is much better to use because a lot less formatting will be required to use it.

Chapter 3:  pp. 73-End       GIS- New– Some drillers have to be accredited, some not.       Semantic heterogeneity in the data:  53 different material terms, prefixed by 41 different adjectives       Well drilling-  Logs in Canada  “Water is considered a provincial resource, and is managed by 10 government.  Agreement on classification entails bringing multiple partners with multiple levels of interest to the table” (79)       Classification/Standardization- “Classification is a political process that reflects the exigencies and cultures of particular institutions” (78)       Data is there—people can use it or ignore it, but if they ignore it… they still have to answer to it (real estate)       Data is created, but then used by other people for other reasons to form an entirely new narrative

GIS- New– Some drillers have to be accredited, some not.

Semantic heterogeneity in the data:  53 different material terms, prefixed by 41 different adjectives

Well drilling-  Logs in Canada  “Water is considered a provincial resource, and is managed by 10 government.  Agreement on classification entails bringing multiple partners with multiple levels of interest to the table” (79)

Classification/Standardization- “Classification is a political process that reflects the exigencies and cultures of particular institutions” (78)

Data is there—people can use it or ignore it, but if they ignore it… they still have to answer to it (real estate)

Data is created, but then used by other people for other reasons to form an entirely new narrative

Retailers take down customers zip codes so that they can put them into a database.  Once they have a database, they can see where the majority of their business comes from and then make tactical decisions about targeting certain areas.  The article says that some retail stores will put billboards up on the routes that they know the people that shop with them travel on.

Chicago 

Senior

Politics and Government Major with Minor in Geography

Sailing

This site helps people search their area to find registered sex offenders in a certain physical area.

2. http://www.dominos.com/home/index.jsp

This site allows customers to locate Dominos pizza retail stores in a given area

3. http://www.cityofchicago.org/Transportation/bikemap/keymap.html

This site lets people search their area and find paved and unpaved bike paths in the Chicago area