Simplification of Parcel Mapping Process and its
Application: Geographical Information System based
Approach
Dr. K.Ezhil Vendhan
©2010 CoreLogic, Inc. Private & Confidential 2
Launched from the First American Corporation, CoreLogic is a
leading provider of consumer, financial and property information,
Analytics and services to business and government
We have more than 1 million users who rely on our data we have
most comprehensive repository of public, contributory and
proprietary data in the US like mortgage information , parcel and
geospatial etc.
We are working with over 40,000 clients in the public and private
sectors
WHO WE ARE
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Introduction
• A parcel map is perhaps the most convenient resource available to
the public to determine the location and Parcel Identification Number
of a property.
• Town officials like Assessors, Planners, Engineers, and others use
parcel maps on a daily basis. So it is very important that parcel maps
should show the current and updated information.
• History shows that most GIS implementation have some difficulties
with parcel mapping process.
• In this perspective CoreLogic internally developed many customized
GIS tools and various methods in AutoCAD Map and ArcGIS
environment for parcel mapping, these methods plays vital role in
creation of new parcel map and updating large quantity of existing
parcel map.
©2010 CoreLogic, Inc. Private & Confidential 4
Basically these methods can be classified into three broad
categories,
I. Pre-Processing
II. Production Process
III. Final – Processing
Aim
The aim of this study is to analyze various methods of parcel
mapping and simplification of the process to improve productivity
and data accuracy.
Processes
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1. Defined Folder Structure
2. Domain Controls in Data base
3. Pre- Defined columns
4. Clipping the county parcel based on available resources
5. Multiple file Re-projection tool
6. Add XY in Single field
7. Clipping stack and Non Stack Polygons
Pre-Processing Methods
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Pre- Processing Methods
Folder Creation Tool
VB Script for Tool Creation
1. Defined Folder Structure
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Create Default Fields
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Create Domain Control
Domain Control
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Clip Stack and Non Stack Line and PIN
Clipped Polygon
Clipped Stack Parcel
Clipped Lines and PINs
Clipping Stack and Non Stack Polygons
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Multiple File Geo Referencing
This tool will be useful to Geo-Reference Multiple File
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Create XY Field in Single Field
The XY creates in same field;
it will be useful to find how may parcel have aligned
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Clipped Polygon
Clipped Stack Parcel
Clipped Lines and PINs
Clipping Stack and Non Stack Polygons
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Parcel mapping Production process are classified under five major
categories.
1.CAD conversion
2.Building parcel Raster to Vector (COGO and Georeference)
3.Maintenance Raster to Vector
4.Maintenance Spatial Alignment Process
5.Maintenance Existing data editing
Production Process
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CAD Conversion Flow Chart
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COGO Method
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Geo-Referencing Method
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Maintenance Parcel – Raster to vector
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Maintenance Spatial Alignment
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Existing Data Editing
Maintain Existing
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In Final process following methods are implemented for data accuracy.
1.Arc Google Synchronize tool
2.Multiple Stack Creation tool
3.Edge Matching
4.Multi Pin Check using Spatial Unique ID Creation
5.Spatial Join/ Forward Link
6.Non- spatial / Reverse Link
7.Summarize Check
8.Color Code
Final Process
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Multi Stack Polygon Creation
Tool
Stack Layer
Data Base
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OID Linking - Multiple Points Identification
Line segment missing - Multiple Points
Multiple points & Null polygons
Polygon is created using the final Line and Point features. Spatial Join (OID linking / Third party tool) is done to check multiple point feature present in a closed line. All NULL and Multiple Points are corrected.
Spatial Join is done to check whether all point features is converted to Polygon.
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Database Forward DB check / Spatial Join
Common fields from the Spatial point feature and the Taxroll data are joined Unjoined DB are exported and verified the errors and it is rectified
Spatial Data Tax Roll data
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Non Spatial \Reverse DB Check
Common fields from the Taxroll data and Spatial point feature are joined
Unjoined DB are exported and verified the errors for rectification
This Method is useful for identified Missing parcels and Stack parcel
Spatial DataTax Roll Data
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By summarizing APN and Map column an output of APN count is obtained for both Tax roll data and Map Data. The Map which has difference in APN count is checked again for errors.
Summarize Check
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Color code (Symbology)
District, Map and BLK are color coded and checked by panning, since dbase check will not clear all the errors
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• CoreLogic captured 124 million parcels for 2,200 counties and
townships Nationwide.
• CoreLogic ParcelPoint ® product enables users to access the
highest level of positional accuracy for developing location-based
solutions.
• Each Parcel’s Unique Identifier allows it to be linked to other forms
of information, including Valuations, Service Areas, Environmental
Factors, Demographics, and Parcel Data also enables sophisticated
spatial analysis such as proximity, overlay and buffer zone
operations.
Parcel Mapping Applications in CoreLogic
©2010 CoreLogic, Inc. Private & Confidential 28
• Integrating ParcelPoint product with flood risk zone is to provide
more flexible and accurate decisions to the decision makers.
• Maintaining taxing jurisdiction data base for determining the
valuation and classification for taxation of property.
• Parcel boundary data helps the homebuyer in identifying the best
fit for new commercial development or matching their desirable
location.
•Developing accurate models for locating fire response area could
be the difference between life and death in emergency situation.
• Parcel data provides an efficient platform for utility companies like
Power Management, Electricity, Gas, Telecommunications etc.
Parcel boundary data is applicable to Insurance Applications
©2010 CoreLogic, Inc. Private & Confidential 29
• Wireless communications companies which are using CoreLogic
data as the underlying map for mobile advertising.
• Government agencies like United States Department of Agriculture
(USDA) and FBI are using CoreLogic data for understanding
Agriculture Trends and Crime Patterns.
• Insurance company State Farm is using parcel and natural hazard
data to better determine insurance rates.
• These different industries have in common need to understand
exactly where a property is on earth and the need to link the
appropriate data to that location.
Various industries relay on CoreLogic for accurate Geospatial Information
©2010 CoreLogic, Inc. Private & Confidential 30
Thank You