Modeling Infill and Urban Growth to Evaluate Agricultural Conversion in Lake County, FL

By Blake HarveyOctober 21, 2011

Committee Chair: Dr. Paul ZwickAssociate Member: Dr. Andres Blanco

Presentation Summary

1. Research Question2. Literature Review3. Methodology

a. Infill Analysisb. LUCIS Scenariosc. Agricultural Analysis

4. Results5. Discussion

Research Question

To what extent can agricultural conversion be prevented in Lake County, Florida, if

intensive urban infill is used to accommodate future urban growth?

1. Research Question

Agricultural Conversion…is a problem

- By 1997, one million acres of farmland per year were being lost to “suburban sprawl”, with 150,000 acres/year in Florida, the fastest rate in the nation (Daniels and Bowers, p.1-2, 1997)

- One third of all agricultural land in Lake County was lost between 2002 and 2007 (USDA, 2007)

…occurs because

- as development encroaches, the “fair market” value increases (Herndon, et al., p.34-35, 1982)

- soils suitable for agriculture are often excellent for development as well

- conflict with new neighbors and competition over water resources (Daniels and Bowers, 1997)

2. Literature Review

Urban Infill

(Image from http://www.ptank.com/blog/2008/12/wordless-wednesday-sf-vacant-lot/)

The development of vacant, underutilized, or abandoned land within urbanized areas. (Real Estate Research Corporation, 1982)

How can Infill mitigate Agricultural Conversion?

• A greater proportion of new growth occurring within cities reduces pressure to expand on the urban fringe (Scott, 2010)

• Transfer of Development Rights (TDR) programs can preserve agriculture by offering incentives to developers to develop within cities instead of on the fringe (Scott, 2010)

• Urban Growth Boundaries (UGB) can restrict fringe growth beyond a certain point, encouraging development of vacant land (Daniels and Bowers, 1997)

2. Literature Review

Methodology – Infill Modeling1. “Infill areas” were created, using principles from Peter Calthorpe’s Next

American Metropolis (1993)- Core Commercial Areas (CCAs) were chosen, based on retail viability

and proximity to downtown areas (as opposed to strip malls)

- Two levels of infill areas were created: more intensive Transit Oriented Developments and more suburban Secondary Areas

2. Property parcel data was used to allocate new residential and commercial uses to vacant parcels, based on suitability data, parcel size, and location

3. Estimates of new population and new employment were calculated

3. Methodology

Methodology – Urban Growth Scenarios

Five scenarios for new urban growth in Lake County for the year 2040 were created, using medium-level population projections which show an increase of 223,648 persons over the next thirty years (Smith and Rayer, 2011).

Growth allocation was completed using LUCIS methodology as described in Smart Land Use Analysis (Carr and Zwick, 2007). Urban growth was modeled in cells with less land use conflict first.

Name of Modeling Scenario

"Trend" Scenario First Infill Second Infill Third Infill Infill Only

Infill Areas… are ignoreduse modeling

resultsuse modeling

resultsuse modeling

results

are built out, with no growth

elsewhere

New Population in New Growth Areas 223,648 188,475 188,475 188,475 0

New Growth Density

1.87 persons/acre (same as gross urban density)

1.87 persons/acre

(same as GUD)

2.81 persons/acre (1.5x GUD)

3.75 persons/acre

(2x GUD)

no growth outside of infill

areas

3. Methodology

Methodology – Agricultural AnalysisAgricultural losses were calculated for:

1. Acres of farm properties

2. Yields for crops that would likely be grown on these farms (i.e. oranges and grapefruit for citrus cropland)

3. Dollar value of each yield lost

• Results for the urban growth scenarios were spatially compared to farms; where growth occurred, the farm was considered to be lost

• Where yields overlapped, they were divided (equally for field crops and 9:1 for citrus) to produce an estimation of total losses

3. Methodology

Infill Results

Leesburg, Lake County,Florida

4. Results

• 1,347 acres of urban infill• 950 acres residential• 372 acres commercial• 25 acres mixed use

• 35,173 new residents

• 23,455 new jobs

Urban Growth and Agricultural Results

4. Results

“Trend” Scenario

119,498 acres of new urban growth (75% increase)0 acres of urban infill

133,189 acres of lost farmland (69% loss)$189,654,997 of lost crops (76% loss)

(new growth density same as GUD, infill areas ignored)

4. Results

First Infill Scenario

100,800 acres of new urban growth (64% increase)1,347 acres of urban infill

115,485 acres of lost farmland (60% loss)$165,463,388 of lost crops (67% loss)

(new growth density same as GUD, infill results included)

4. Results

Second Infill Scenario

67,224 acres of new urban growth (42% increase)1,347 acres of urban infill

81,828 acres of lost farmland (42% loss)$119,304,716 of lost crops (48% loss)

(new growth density 1.5 times GUD, infill results included)

4. Results

Third Infill Scenario

50,280 acres of new urban growth (32% increase)1,347 acres of urban infill

59,432 acres of lost farmland (31% loss)$89,796,050 of lost crop yield (36% loss)

(new growth density two times GUD, infill results included)

4. Results

Infill Only Scenario

0 acres of new urban growth (0% increase)3,333 acres of urban infill

522 acres of lost farmland (0.27% loss)$1,021,655 of lost crop yield (0.41% loss)

(infill areas built out; no other growth)

4. Results

Discussion of Results1. If urban growth in Lake County continues at the

present gross urban density (GUD), significant agricultural conversion will result.

2. Intensive urban infill will reduce these losses to some degree, but a majority of the county’s agriculture still faces conversion

3. The Second and Third infill scenarios suggest that at least for this study area, higher new growth densities are more effective at curbing sprawl than infill is.

5. Discussion

Recommendations for Further Research

1. Repeat similar modeling exercises for new study areas with different conditions

2. Simulate the effect of policies such as Urban Growth Boundaries and Transfer of Development Rights in reducing agricultural conversion

5. Discussion

References

Daniels, T. L., & Bowers, D. (1997). Holding our ground: Protecting America's farms and farmland. Washington, D.C: Island Press.

Scott, Jean. (2010). Florida planning toolbox, Center for Urban and Environmental Solutions, Florida Atlantic University, Boca Raton, Florida. Retrieved from http://www.cues.FAU.edu/toolbox/about_us.asp

United States Department of Agriculture, National Agricultural Statistics Service. (2007). The census of agriculture Retrieved from http://www.agcensus.usda.gov/About_the_Census/index.asp

Carr, M, & Zwick, P. (2007). Smart land use analysis: the lucis model. Redlands, CA: ESRI Press.

Smith, S. & Rayer, S. (2011). Projections of florida population by county, 2010–2040.Florida Population Studies, 44(159), 1-8.

Calthorpe, P. (1993). The next American metropolis: Ecology, community, and the American dream. New York: Princeton Architectural Press.