Kaelyn Wilke
Analysis of Urban Structure in Minnesota’s Twin Cities:
Accessibility and Land Use
Bolobilly at http://www.flickr.com/photos/61518665@N00/274963584
Presentation Outline• Background• Previous Research• Research Question• Maps of the Study Area, Buffer
Zones, and Land Use• Methods• Variable Layers and Results• Conclusions• Future Research• Data Sources• Bibliography
Urban Structure and Growth
Urban structure
Layout of howland is used in a city
crimetheory.com, gearthblog.com
Denver
Urban Structure and Growth
• One of the most famous models is the Concentric Zone Model
– Origin: Henry Burgess, 1920s
– Explains land use as expanding out of a central business district, or CBD.
– Good demonstration of the attempt to classify trends in the development of cities, or urban structure.
crimetheory.com, gearthblog.com
Denver
Urban Centrality and Accessibility
Does the method of measurement depend on the model?
Background
Urban structure is a prominent theme in urban geography. Another aspect examined in urban development is accessibility. Accessibility refers to the ease of traveling from one location to another. Could there be a causal relationship between accessibility and land use? If so, there should be correlations of a measure of accessibility with the exploitation and infrastructure of the city.
Previous Research
• Relationship between accessibility and land use
• Two ways to measure accessibility • Relative Accessibility
– Proximity to downtown• Integral Accessibility
– Travel times and network connectivity
Stanilov, Kiril. 2003. Accessibility and Land Use: The Case of Suburban Seattle, 1960–1990. Regional Studies, Vol. 37.8, pp. 783–794.
Previous Research
• Two-way relationship between land use and accessibility
Ottensmann, John, R., Using the Land Use in Central Indiana (LUCI) Models inTransportation Planning, Indiana University Purdue University Indianapolis
www.ces.purdue.edu/ecd/Purdue_Land_Use_Team_John_Ottensmann.ppt, Esri, Opus Corp
•Land use affects accessibility•Accessibility and transportation
affect or lead to changes in land use
Previous Research
• Issues with accessibility – Personal choice– Impedance– Population traits
• (age, socio-economics)
• Method of measurement– Polygon– Patterns of human
behavior– Infrastructure
Makri, M.C., Folkesson, C. Accessibility Measures for Analyses of Land Use and Travelling with Geographical Information Systems Lund Universtiy, Sweden. University of Karlskrona?Ronneby,
Sweden.
nytimes.com, pro.corbis.com, flickr- Aaron Michael Brown
Research Questions• What are appropriate measures of accessibility?• How does accessibility affect the land use in the Twin
Cities? – Canopy, Pavement, Farmland, Retail
panoramas.com
Study Area
Twin Cities of Minnesota
The metropolitan area includes the seven counties:
Ramsey, Hennepin, Anoka, Scott, Dakota, Carver, and
Washington.
The Concept of Creating Buffers
Buffers were created to encompass different modes of accessibility in order to relate it to land use:
hamptonroads.com/node/204931; http://commons.wikimedia.org/wiki/Image:Houston_Texas_CBD.jpg
Relative accessibility: steady outward distances from CDB
Integral accessibility: time to travel to highway intersections
Map of Buffer Zones
Distance from Downtowns
Distance from Downtowns (Miles)
0-1
1-2
2-3
3-4
4-5
5-6
6-7
7-8
8-9
9-10
10-11
11-12
12-13
13-14
14-15
Map of Buffer Zones
Time to Intersections:• The place where
highways crossed or meet has been termed “intersections.”
• Polynucleated urban space
Time to Intersections (Minutes)0-1
1-2
2-3
3-4
4-5
5-6
6-7
7-8
8-9
9-10
10-11
11-12
12-13
13-15
15-20
Example of Buffer Use: Farmland
Relationship Between Farmland and Proximity to Downtowns
0
200
400
600
800
1000
1200
1400
1600
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Distance to Downtowns (Miles)
Num
ber o
f 30
x 30
Far
mla
nd C
ells
Appropriate Buffer Zones as Measures of Accessibility
Unit of measure is in distance Unit of measure is in time
Distance from Downtowns (Miles)0-1
1-2
2-3
3-4
4-5
5-6
6-7
7-8
8-9
9-10
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Time to Intersections (Minutes)
0-1
1-2
2-3
3-4
4-5
5-6
6-7
7-8
8-9
9-10
10-11
11-12
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Methods
Note: any variable can be inserted where it says “Landuse Type.”
Map of Variable: Canopy
• Tree coverage over the seven metropolitan counties.
• Dark blue denotes the most tree coverage, and tan denotes the least tree coverage.
Results: Canopy Layer
Map of Variable: Imperviousness
• Areas in the seven metropolitan counties characterized by spans of concrete.
• Dark green signifies the most impervious areas (“most concrete”), and tan denotes the least impervious areas (“least concrete”).
Results: Imperviousness Layer
Map of Variable: Retail and Other Commercial Land Use
• Areas in the seven metropolitan counties characterized by spans of infrastructure.
• Red shading denotes map parcels with retail and commercial uses.
Results: Retail and Other Commercial Land Use Layer
Conclusions
The results support the theory that accessibility affects land use.
When used with the “Distance to Downtowns” and “Time to Intersections” buffer, very little trees are seen closest to downtowns or highway intersections, respectively.
Expanding outward, the amount of tree coverage steadily increased.
http://www.riversides.org/
Conclusion: Canopy Layer
Conclusion: Impervious Layer
When used with the “Distance to Downtowns” buffer and “Time to Intersections” buffer, the results showed a lot of concrete near downtowns or highway intersections, respectively.
Expanding outward, the land is less covered with pavement.
http://www.geosyntec.com
• The results supported the theory that accessibility dictates land use.
• Retail and other commercial land uses were each prevalent with the CBD.
• Is one buffer better than the other in terms of measuring urban structure? In other words, does the Concentric Zone Model still apply to urban development today?
Conclusions: Land Use Layers
Appropriate Buffer Zones as Measures of Accessibility
*Distance *Relative Accessibility *Time *Integral Accessibility *One center *Network *Polynuceated
Both models are comparable for canopy and impervious layersSome difference is seen in the RCO layer
Large categories More specific categories
Distance from Downtowns (Miles)0-1
1-2
2-3
3-4
4-5
5-6
6-7
7-8
8-9
9-10
10-11
11-12
12-13
13-14
14-15
Time to Intersections (Minutes)0-1
1-2
2-3
3-4
4-5
5-6
6-7
7-8
8-9
9-10
10-11
11-12
12-13
13-15
15-20
Future Research
What type of variables are buffer-dependent?
(Model dependent)
Apply the same methods to different cities to see if urban structure varies enough to affect accessibility, which affects land use.
Data Sources
National Land Cover Database Tree Canopy LayerHomer, C., C. Huang, L. Yang, B. Wylie and M. Coan, 2004. Development of a 2001 national land cover database for the United States. Photogrammetric Engineering and Remote Sensing.
National Land Cover Database Zone 51 Imperviousness LayerYang, L, C. Huang, C. Homer, B. Wylie, and M. Coan, 2002. An approach for mapping large-area impervious surfaces: Synergistic use of Landsat 7 ETM+ and high spatial resolution imagery. Canadian Journal of Remote Sensing, 29: 2, 230-240.
Generalized Land Use - Historical 1984, 1990, 1997, 2000 and 2005, for
the Twin Cities Metropolitan Area 2006. Metropolitan Council. This dataset can be downloaded from http://www.datafinder.org/cafe.asp
TLG Street Centerline and Address Ranges 2008. The Lawrence Group. Distributed by the Metropolitan Council
Bibliography
Stanilov, Kiril. 2003. Accessibility and Land Use: The Case of Suburban Seattle, 1960–1990. Regional Studies, Vol. 37.8, pp. 783–794.
Makri, M.C., Folkesson, C. Accessibility Measures for Analyses of Land Use and Travelling with Geographical Information Systems Lund Universtiy, Sweden. University of Karlskrona?Ronneby, Sweden.
Ottensmann, John, R., Using the Land Use in Central Indiana (LUCI) Models in Transportation Planning, Indiana University Purdue University Indianapolis
• Also, thanks to Dr. Paul Lorah, Renee Huset, and Jeff Dodson
Thank You
Questions?