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. - To expand their already extensive modeling capabilities the El Paso MPO has Partnered with NMSU to explore the use of UrbanSim. - - NMSU’s role thus far has been to develop portions of the initial database and to conduct a pilot study which we will talk about today.

- 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 microsimulation based behavioral model. (Wadell, 2002) Reflects 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. Primary Tables: All data necessary to run UrbanSim Primary Tables: Gridcells Jobs Households The 58 tables include all data needed to run UrbanSim. Primary Tables are Gridcells, Jobs, and Housholds. Simple Right?

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 … The size of the gridcells is arbitrary.

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 How does UrbanSim address land use policy?

Analysis Run UrbanSim Trend Run: UGB 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. Before we look at the results of the study it is important to note that there is some uncertainty in modeling and in the future. But in beginning to use UrbanSim we can look to the advances in urban and economic theory and computing technology and do our best to reduce error and provide the model with the best data available so that we have reduced uncertainty to acceptable levels.

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. 1997-2027. Using FEMA 100year Flood data, development was disallowed in floodzones. Planned Development: Add 1000 housing units. 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?