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!!