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)

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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

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Example of Buffer Use: Farmland

Relationship Between Farmland and Proximity to Downtowns

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Distance to Downtowns (Miles)

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mla

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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

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Time to Intersections (Minutes)

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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

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Time to Intersections (Minutes)0-1

1-2

2-3

3-4

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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?