User Manual¶
General Description¶
UPlan 4 converts UPlan from a raster to a vector GIS model. The concepts that it uses to project where growth are largely unchanged, though many have been refined.
UPlan 4 is written primary in Python using Esri’s ArcPy tools. Additionally, UPlan4 uses the Pandas library for Python to extend Python’s capabilities. At the moment, pandas is an additional (free) installation, though Esri has stated that it will likely be including pandas in future Python installations for ArcGIS.
Terms¶
UPlan Geodatabase (UPGDB): An Esri file Geodatabase that has had the UPlan tracking tables added to it. This geodatabase will be a self-contained record of all of the inputs and settings for a UPlan scenario. The geodatabase can be updated and a new allocation run, but this will overwrite your prior results.
Base Geometry or BaseGeom: This polygon feature class provides the minimum mapping units that UPlan will track. These may be derived from parcels, a grid (also known as a Fishnet), voronoi polygons, or any other set of polygons that you wish to use provided that they are sufficiently small in size to represent the level of detail you wish to achieve. Some tools will be provided to assist with preparing the base geometry layer. Each feature in the BaseGeom must have a unique integer id assigned to it. We’ve been using ‘pclid’ as the field name, but any alternative may be used. When importing the BaseGeom into the UPGDB, a derivative feature class will be created that converts the polygons into a point dataset based on the polygon’s centroids.
Allocation: Full allocation means that all land use demand (based on the demographic inputs) has been accommodated within the model run. The resulting table tells us how many acres of each land use are assigned to each BaseGeom polygon. Under allocation means that one or more land use was not able to be accommodated fully during the model run. Depending on the purpose of the run, this should be addressed appropriately.
Land Use: A land use is either residential or employment and allows for some portion of vacant space, and residential vacant housing units within the land use. Land uses are permitted to develop in a user specified list of General Plan categories.
Subareas: A subarea is a subsection of the model’s geographic coverage that can have distinct control totals for population and employment assigned to it.
Redevelopment: (optional)The redevelopment dataset indicates how many people currently live or work on each polygon. If development on these polygons is not prohibited by a constraint (or general plan), when those polygons are selected for development, the population and employment totals are added to a tally and a second (or third...) iteration of the allocation is done to accommodate those displaced. This could result in a large number of iterations and might take a long time to achieve full allocation.
TimeStep: A time step allows the specification of almost all UPlan settings to be applied. Features that cannot be customized for each TimeStep: BaseGeom, Subareas, Redevelopment, and Land Uses. For example a run with two time steps could run one from 2015-2025, and a second from 2025-2035. Each time step can have independent demographic projections, attractors, constraints, and general plans.
General Plan: A general plan layer defines where land uses are permitted to develop.
Mixed Use: General plan categories may allow two or more otherwise permitted land uses to coexist on the same polygon. For example: a downtown mixed use category may allow res. high and retail to both occupy the same polygon. Note that each of these land uses is assumed to cover the entire polygon in a vertical mixed use format.
Constraint: A constraint reduces the available space for development for a land use as a percent of the land area. For example: a polygon overlapped by a wetland might have a 50% reduction in developable space, and a polygon that is already fully developed might have a 100% reduction. When multiple constraints overlap, their constraints are summed. i.e. an overlapping 50% and 25% set of constraints would have a final effect of being a 75% reduction in developable space. Constraints are calculated based on the union of all constraining layers with the BaseGeom. After calculating that union, and the net constraint on each resulting polygon, the developable space for each land use is summed and assigned back to the BaseGeom polygons.
Attractor: Attractors are used to prioritize where growth occurs when there is more space than required for a land use. Attractors can be both positive and negative(i.e. a discourager). Each land use can have independent attractors. Attractors are now defined as the attraction at a distance from the attractor layer. The weight is then interpolated between each consecutive set of weighted points.
Quick Guide¶
Overview¶
- Create a UPGDB
- Prepare the BaseGeom dataset
- Import BaseGeom
- Import any needed Subarea, Constraint, Attractor, General Plan, and Redevelopment datasets.
- Specify settings for Land uses including densities, demographics, levels of constraints, attractors, and general plans.
- Precalculate: Constraints, General Plan permissions, weights, and land use demand.
- Allocate land uses
- Post-Run Analysis and visualization
Create UPGDB¶
Tool under development
Prepare BaseGeom¶
Tools under development
Import BaseGeom¶
Use the BaseGeom import tool (mostly complete)
Import Other Datasets¶
Tools under development
Specify Settings¶
Tools under development
PreCalculate¶
Constraints¶
Use the tool (UI not complete, but primary code is finished)
General Plans¶
Use the tool (UI not complete, but primary code is finished)
Attraction Net Weights¶
Use the tool (UI not complete, but primary code is finished)
Demographics/Land Use Demand¶
Use the tool (UI not complete, but primary code is nearly finished)
Allocation¶
Use the tool (UI not complete, but primary code is finished)
Post-Process¶
Visualization¶
Tools under development for final allocation, net attraction, constraints, and general plans
Zonal Summary¶
Tool under development. This will provide basic TAZ export support as well as summaries by other geographies (constraints, zones)
Reporting¶
Tool under development. Text based output and reporting of results.
