EVALUATING THE FUTURE:
FORECASTING URBAN
DEVELOPMENT USING THE
URBANSIM LAND USE MODEL IN
EL PASO, TX.
Quinn P. Korbulic
- Background

The El Paso MPO has invested in expanding their
modeling capabilities to include land use modeling.
 They

chose to explore UrbanSim.
NMSU Spatial Applications & Research Center
 Developed
portions of initial UrbanSim database
 Conducted UrbanSim Pilot Study.
- Study Objectives

Objectives
 Develop
& Test UrbanSim Database
 Run UrbanSim from 1997 to 2027 for two scenarios.
 Trend
(Business as Usual) Scenario
 Urban Growth Boundary Scenario
 Convert
the results to GIS format.
 Compare geographic variables from the output of
UrbanSim for the two scenarios.

Add picture of EP MPO study area with the Pilot
study area
Study Area


Area: 181.2 sq km
Approximate Pop.
 92,086
(2000 Census)
UrbanSim

UrbanSim
 Multi-agent
 (Wadell,
 Reflects
microsimulation based behavioral model.
2002)
the individual choices of:
 Households
 Businesses/employees
 Developers
 Governments
 and
their interaction with the real estate market over
time.
UrbanSim
- Exogenous data, e.g. economic and population forecasts
- Travel Data, e.g. travel time to CBD, general travel times
-Demographic and Economic: Controls agents entering and leaving the
system. Agents entering the system are regulated by control totals
from exogenous data.
- Households and Jobs: will they relocate? Yes/No
- Driven by relocation rates (exogenous data) for jobs by employment
sector and households by household type.
- Households, Jobs, and Development Projects: determines the probability
that an agent will choose a specific location. Monte Carlo Simulation
chooses the location for each agent.
- Updates land prices annually after all development and market
activity are completed.
UrbanSim Data

UrbanSim Datastore: 58 related tables.
 All

data necessary to run UrbanSim
Primary Tables:
 Gridcells
 Jobs
 Households
Application of GIS

The application of GIS played a critical role in
the development of the UrbanSim database:
 Tables:
 Connected
to space through GIS – space alone isn’t
enough
 Attributes – provide a connection to what exists on the
ground
 Otherwise, we’d just have location, not the what, when,
why, or maybe even how.
Gridcells
Gridcells: 8054
 150m x 150m
 31 Attribute Fields
 e.g.
 Slope
 Land Value
 Sqft by use
 zoning
…

Jobs &
Households
Households: 30,595
 Household Attributes
 Persons
 Workers
 Age of Head
 Income
 Children
 Cars
…
 Jobs: 16,185
 Jobs Attributes
 Employment Sector
 Location

UrbanSim and Land Use Policy

The Development Constraints Table.
User defined development rules, i.e. zoning.
 Can take into account any variable in the gridcells table, for
example

Plan type (zoning)
 Building Square footage
 Proximity to Highways
 Etc…


Mandatory Fields
Min/Max Housing Units
 Min/Max Commercial Sqft
 Min/Max Industrial Sqft

Analysis

Run UrbanSim
 Trend
Run:
 1997-2027
with no significant changes to development
constraints table.
 UGB
Run
 1997-2027
with UGB introduced into the development
constraints table.
Modeling Uncertainty

“Essentially all models are wrong; the practical
question is how wrong do they have to be to not be
useful.”
 George
Box, University of Wisconsin.
1997 Baseyear
2027 Trend Forecast
2027 Trend Forecast
2027 UGB Forecast
2027 Trend Total Density
2027 UGB Total Density
1997 TAZ Population
2027 TAZ Population
1997 TAZ Jobs
2020 TAZ Jobs
More Scenarios

Floodzones: No Development Allowed.


Planned Development: Add 1000 housing units.


1997-2027. Using FEMA 100year Flood data, development
was disallowed in floodzones.
1997-2027. To begin to accommodate for BRAC troop
influx.
Three Scenarios Combined:
1997-2027
 No Development in Floodzones
 Planned Development
 Open Castner Range to Development

1997 Trend
2027 Floodzone
1997 Trend
2027 Planned Development
1997 Trend
2027 Three Scenarios
Conclusions

Overall, we found that the Urban Growth Boundary
did restrict new urban development.
 Also,
it is a fairly simple process to develop new land
use scenarios and to run them one at a time or together

GIS played a non-trivial role in the development of
the database, and display of the results.
Questions?