260 likes | 426 Views
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 .
E N D
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.
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. • 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. • 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.