less well-known geospatial datasets property value history property attribute history building...
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Less Well-Known GeoSpatial Datasets
• Property Value History• Property Attribute History• Building Permits• Population Models
Less Well-Known GeoSpatial Datasets
• Property Value History• Property Attribute History• Building Permits• Population Models
Property Value History
• Relevant jocoPub FCs & SDE Views– PropertyValueHistory_PT– PropertyValueHistoryFlat_PT– Subdivision_PL_vw1– Subdivision_PL_vw3
• Relevant Layer Files– PropertyValueHistory.lyr– SubdivisionPropertyValue.lyr
(Re-created Nightly)
PropertyValueHistory_PT
• One point for each unique combination of current TaxPropID + TaxYear
• For most TaxPropIDs, there will be 12 coincident points (1996-2007)
• > 2,000,000 points
PropertyValueHistory_PT
• Points are located at the centroid of the "best" polygon for a TaxPropID
PropertyValueHistory_PTLimitations!
• Current TaxPropIDs • TaxPropIDs that existed in previous years
but do not exist now … are not represented.
• Not every TaxPropID that exists now was in existence for the past 12 years.
• Even though a TaxPropID exists now and has historical value data, that doesn't mean that that TaxPropID existed in the same configuration (shape or legal description) over time.
PropertyValueHistory.lyr
PropertyValueHistoryFlat_PT
• One point for each unique combination of current TaxPropID + TaxYear
• For most TaxPropIDs, there will be 12 coincident points (1996-2007)
• > 2,000,000 points 208,000 points
Subdivision_PL_vw1
• One polygon for each unique combination of current Subdivision + TaxYear
• For most Subdivions, there will be 12 coincident polygons (1996-2007)
• ~ 32,000 polygons
SubdivisionPropertyValue.lyr
Subdivision_PL_vw3
• One polygon for each unique combination of current Subdivision + TaxYear
• For most Subdivisions, there will be 12 coincident polygons (1996-2007)
• ~ 32,000 polygons ~3,000 polygons
1996
1997
1998
Less Well-Known GeoSpatial Datasets
• Property Value History• Property Attribute History• Building Permits• Population Models
Small Community Focus Group
• “History is helpful when investigating a single parcel, but I need to know where ownership changes (and other property attribute changes) have taken place without having to investigate each parcel in my City.”
"I would like to be able to receive a report each month that indicates which parcels in my city have undergone a change in ownership. And for our enforcement of our rental licensing requirement, it would be especially nice to know when ownership changes on rental properties … and can you help us locate “unregistered rental homes”.
PropertyUpdates.xls
• New .xls generated at the beginning of each month (reports updates from previous month).
• “AllFieldsSummary” worksheet• “OwnerNameDetail” worksheet
AllFieldsSummary
Shapefile
UsingAllFieldsSumma
ryShapefile
Less Well-Known GeoSpatial Datasets
• Property Value History• Property Attribute History• Building Permits• Population Models
Permit_PT
• ~ 109,000 points• All Building Permits issued between
February 2000 – May 2007 (currently)
• Source: APR
Less Well-Known GeoSpatial Datasets
• Property Value History• Property Attribute History• Building Permits• Population Models
Relevant jocoPub FCs & SDE Views
• PopulationModel1_PT• PopulationModel2_PT• PopulationModel3_PT• Subdivision_PL_vw2• Commissioner_PL_vw2• PLSS_PL_vw1• PLSSQuarter_PL_vw1• VotingPrecinct_PL_vw2• More SDE Views coming …
(Re-created Nightly)
(Re-created Nightly)
(Updated Nightly)
(Updated Nightly)
(Updated Nightly)
(Updated Nightly)
(Updated Nightly)
Relevant Layer Files
• AddressesResidentialHouseholdSize.lyr• PropertyResidentialHouseholdSize.lyr• SubdivisionPopulation.lyr• CurrPopEstByCommissionerDistrict.lyr• CurrPopEstBySectionModel1.lyr• CurrPopEstBySectionModel2.lyr• CurrPopEstByVotingPrecinctModel1.lyr• CurrPopEstByVotingPrecinctModel2.lyr• More layer files coming …
PopulationModel1_PT
• Logic originally developed by CERI/Steen, but has been modified subsequently
• Each point represents the centroid of a Residential Parcel Polygon (NumDwellUnits > 0).
Each point contains the estimated number of persons residing at the parcel (in a field named Occupants).
Occupants is calculated by multiplying the NumDwellUnits for the parcel by the Average Household Size for the specific CERI ZIP that the point resides in. This result is then multiplied by 1 – the Vacancy Rate for the specific CERI ZIP that the point resides in.
Average Household Size and Vacancy Rate is not only based on CERI Zip, but owner/renter (using GenLandUse2).
PopulationModel2_PT• Developed by Yoder to address currency and granularity
shortcomings of Model 1. • Each point represents an individual residence ... an address
point which resides in a parcel polygon whose GenLandUse1 (MARC/OP) is SnglFamRes or TwoFamRes or MultFamRes …
– or an address point which resides in a parcel polygon whose LandUse value is 811* (Farm/Ranch with Improvements) or 100* (Vacant Residential Land)
• Each point contains the estimated number of persons residing at the Residence (in a field named Occupants).
• Occupants is equal to Average Household Size for the specific Census Block that this point resides in multiplied by 1 – the Vacancy Rate for the specific Census Tract that this point resides in.
Average Household Size and Vacancy Rate is not only based on Census Block and Tract, but owner/renter (using GenLandUse1).
The number of Occupants at any given Residence may be overriden by virtue of an “active” record in an “Occupants Override” table Nursing homes, assisted living facilities, college dormitories, jails, prisons
PopulationModel1_PT
PopulationModel2_PT
Use of Models with Custom/Variable Geography
Subdivision_PL_vw2
SubdivisionPopulation.lyr
Use of Models with Pre-Defined Geography
PLSS_PL_vw1
CurPopEstBySectionModel2.lyr
Use of Models with Pre-Defined Geography
Relevant Layer Files
• AddressesResidentialHouseholdSize.lyr• PropertyResidentialHouseholdSize.lyr• SubdivisionPopulation.lyr• CurrPopEstByCommissionerDistrict.lyr• CurrPopEstBySectionModel1.lyr• CurrPopEstBySectionModel2.lyr• CurrPopEstByVotingPrecinctModel1.lyr• CurrPopEstByVotingPrecinctModel2.lyr• More layer files coming …
Use of Models with Pre-Defined Geography
PopulationModel3_PT
• Developed by Porter in context of 2007 BOCC Redistricting.• Each point represents an individual residential building
permit (since 2000).• Each point contains the estimated number of persons
residing at the Residence (in a field named Occupants).• Occupants is calculated in the same manner as Population
Model 2 … AHS for Block * (1 – Vacancy Rate for Tract) … owner/renter considered for AHS & Vacancy Rate.
• To estimate population in a particular area, must add 2000 population to the sum of Occupants in the area.
• Like 1 & 2, can use with Custom/Variable Geography in ArcMap or with Pre-Defined Geography.
• Most closely reflects current Census Bureau estimates.
