March 14, 2007
First Steps For Starting First Steps For Starting Your Parcel Database:Your Parcel Database:
Aurora Case StudyAurora Case Study
Indiana GIS ConferenceDearborn County GIS
Ileana Abot
March 14, 2007
OutlineOutline
OverviewOverview OverviewOverview
Main Task - problemsMain Task - problems Main Task - problemsMain Task - problems
Method/alternative selectedMethod/alternative selected Method/alternative selectedMethod/alternative selected
different methods - comparisondifferent methods - comparison different methods - comparisondifferent methods - comparison
Experience/conclusionsExperience/conclusions Experience/conclusionsExperience/conclusions
March 14, 2007
OverviewOverview
Hired by Dearborn County in June, 2006Hired by Dearborn County in June, 2006 Hired by Dearborn County in June, 2006Hired by Dearborn County in June, 2006
help on daily requests for GIS: Maps, Datahelp on daily requests for GIS: Maps, Data help on daily requests for GIS: Maps, Datahelp on daily requests for GIS: Maps, Data
Continue working on Aurora Zoning MapContinue working on Aurora Zoning Map Continue working on Aurora Zoning MapContinue working on Aurora Zoning Map
Collaborate with County Historic Collaborate with County Historic Structures ProjectStructures Project
Collaborate with County Historic Collaborate with County Historic Structures ProjectStructures Project
Participate on GIS Task Force MeetingsParticipate on GIS Task Force Meetings Participate on GIS Task Force MeetingsParticipate on GIS Task Force Meetings
March 14, 2007
City of AuroraCity of Aurora
S.E. of Dearborn Co.S.E. of Dearborn Co. S.E. of Dearborn Co.S.E. of Dearborn Co.
Population: almost 4,000 ha.Population: almost 4,000 ha. Population: almost 4,000 ha.Population: almost 4,000 ha.
Incorporated community Incorporated community Incorporated community Incorporated community
March 14, 2007
Zoning MapZoning Map
March 14, 2007
Main TaskMain Task
Started working on Zoning LayerStarted working on Zoning Layer Started working on Zoning LayerStarted working on Zoning Layer
Software: Worked with ArcEditorSoftware: Worked with ArcEditor Software: Worked with ArcEditorSoftware: Worked with ArcEditor
Existent Parcel Layer (historic district)Existent Parcel Layer (historic district) Existent Parcel Layer (historic district)Existent Parcel Layer (historic district)
Edited Existent Zoning DraftEdited Existent Zoning Draft Edited Existent Zoning DraftEdited Existent Zoning Draft
Needed more accurate dataNeeded more accurate data Needed more accurate dataNeeded more accurate data
March 14, 2007
First ProblemFirst Problem
Lack of Parcel dataLack of Parcel data Lack of Parcel dataLack of Parcel data
BOUNDARIES ???BOUNDARIES ??? BOUNDARIES ???BOUNDARIES ???
March 14, 2007
First ProblemFirst Problem
BOUNDARIES ???BOUNDARIES ??? BOUNDARIES ???BOUNDARIES ???
Parcels 100 Ft. offParcels 100 Ft. off Parcels 100 Ft. offParcels 100 Ft. off
March 14, 2007
First DecisionFirst Decision
Start working on Parcel LayerStart working on Parcel Layer Start working on Parcel LayerStart working on Parcel Layer
assign parcel project for whole countyassign parcel project for whole county assign parcel project for whole countyassign parcel project for whole county
Select from available methodsSelect from available methods Select from available methodsSelect from available methods
Choose existent layers for referenceChoose existent layers for reference Choose existent layers for referenceChoose existent layers for reference
Gather all useful data (digital, maps)Gather all useful data (digital, maps) Gather all useful data (digital, maps)Gather all useful data (digital, maps)
March 14, 2007
MethodsMethods
Vary on Accuracy and costVary on Accuracy and cost Vary on Accuracy and costVary on Accuracy and cost
Digitize scanned maps (subdivision plats)Digitize scanned maps (subdivision plats) Digitize scanned maps (subdivision plats)Digitize scanned maps (subdivision plats)
Use orthophotos for heads up digitizingUse orthophotos for heads up digitizing Use orthophotos for heads up digitizingUse orthophotos for heads up digitizing
Include COGO descriptions: not feasibleInclude COGO descriptions: not feasible Include COGO descriptions: not feasibleInclude COGO descriptions: not feasible
Integrate survey data (cad): not availableIntegrate survey data (cad): not available Integrate survey data (cad): not availableIntegrate survey data (cad): not available
March 14, 2007
Comparison of MethodsComparison of Methods
VectorizedMaps
Digitized Orthophotos
CogoMeasurement-Based system
AccuracyAccuracy lowest better good highest
costcost lowestModerately
higherMuch higher
higher
Maintenance Maintenance CostCost
highestModerately
lowerlower lowest
Vertical Vertical IntegrationIntegration
poor Slightly higher good best
BenefitsBenefitsFast way to get started
Fast way to get started
Detects conflicts
Integrates gis and legal
descriptions
Source: Designing Geodatabases: Case Studies in GIS Data Modeling, d. arctur and M. zeiler, Source: Designing Geodatabases: Case Studies in GIS Data Modeling, d. arctur and M. zeiler, ESRI, 2004ESRI, 2004
March 14, 2007
Parcels DatabaseParcels Database
Development Process Development Process Development Process Development Process
Phase 1Phase 1 Phase 2Phase 2 Phase 3Phase 3
Collect data and
line work
Collect data and
line work
Convert to
Polygons
Convert to
Polygons
Add Attribute
Data
Add Attribute
Data
March 14, 2007
Method SelectedMethod Selected
Combined methodCombined method Combined methodCombined method
Vectorized Maps: Edit existent DataVectorized Maps: Edit existent Data Vectorized Maps: Edit existent DataVectorized Maps: Edit existent Data
Digitize scanned maps (subdivision plats)Digitize scanned maps (subdivision plats) Digitize scanned maps (subdivision plats)Digitize scanned maps (subdivision plats)
Digitized orthophotosDigitized orthophotos Digitized orthophotosDigitized orthophotos
March 14, 2007
Base DataBase Data
Indiana Orthophotography ProjectIndiana Orthophotography Project Indiana Orthophotography ProjectIndiana Orthophotography Project
Existent Parcel Layer (Line Work)Existent Parcel Layer (Line Work) Existent Parcel Layer (Line Work)Existent Parcel Layer (Line Work)
New Subdivision PlatsNew Subdivision Plats New Subdivision PlatsNew Subdivision Plats
Zoning OrdinancesZoning Ordinances Zoning OrdinancesZoning Ordinances
Knowledge provided by local authoritiesKnowledge provided by local authorities Knowledge provided by local authoritiesKnowledge provided by local authorities
March 14, 2007
Edited existingEdited existing Line Work Line Work
Moving BlocksMoving Blocks Moving BlocksMoving Blocks
March 14, 2007
ProcessProcess
CollectData
Scan Geo-reference
Edit &Digitize
Verify
CycleCycle
IncorporateHard - Copy Maps
March 14, 2007
Geo-ReferencingGeo-Referencing
Locate your data in real world coordinatesLocate your data in real world coordinates Locate your data in real world coordinatesLocate your data in real world coordinates
March 14, 2007
Geo-ReferencingGeo-Referencing
All layers must be aligned (Use Control points)All layers must be aligned (Use Control points) All layers must be aligned (Use Control points)All layers must be aligned (Use Control points)
March 14, 2007
Potential ErrorsPotential Errors
Accuracy of original field measurementsAccuracy of original field measurements Accuracy of original field measurementsAccuracy of original field measurements
Scale of source mapScale of source map Scale of source mapScale of source map
Accuracy of original draftingAccuracy of original drafting Accuracy of original draftingAccuracy of original drafting
Digitizing accuracyDigitizing accuracy Digitizing accuracyDigitizing accuracy
Conflict between different recordsConflict between different records Conflict between different recordsConflict between different records
March 14, 2007
ProcessProcess
Better AccuracyBetter Accuracy
CONSISTENTWITHSCALE
USEUSEROW FROMROW FROM
STREET STREET CENTERLINESCENTERLINES
USESNAPPING
TOOL
March 14, 2007
SnappingSnapping
Improves accuracy on vertices and edges junctionsImproves accuracy on vertices and edges junctions Improves accuracy on vertices and edges junctionsImproves accuracy on vertices and edges junctions
March 14, 2007
ExperienceExperience
City has GIS starting pointCity has GIS starting point City has GIS starting pointCity has GIS starting point
Without knowing Building Parcel DatabaseWithout knowing Building Parcel Database Without knowing Building Parcel DatabaseWithout knowing Building Parcel Database
Trial and error processTrial and error process Trial and error processTrial and error process
Plan Commission Meetings: FeedbackPlan Commission Meetings: Feedback Plan Commission Meetings: FeedbackPlan Commission Meetings: Feedback
Also located billboards and cell towersAlso located billboards and cell towers Also located billboards and cell towersAlso located billboards and cell towers
March 14, 2007
Final ResultsFinal Results
March 14, 2007
Thank you!!Thank you!!
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