This document summarizes GIS analysis and visualization collaboration between libraries and county GIS staff. It includes maps and data on checkout patterns and demographic trends for West Regional and North Regional libraries. One week of checkout data is visualized to show that 78% of checkouts from West Regional and 62% of checkouts from North Regional were within a 10 minute drive time. Additional analysis looked at library service areas defined by 10, 13, and 15 minute drive times and percentages of households and cardholders within each area. Possibilities for further analysis are discussed.

1. Library GIS Analysis & Visualization
October 2010

2. Collaboration
Libraries
CS Admin • Elizabeth Caran
• Bill Scanlon • Theresa Cummings
• Johanna Foster • Lynn Bertino
• Jamaar Hosier • John Schodtler
GIS
• Charles Friddle
• Anne Payne
• Lisa Sago
• Carter Vickery

3. WRL & NOR Checkout Patterns &
Demographic Trends
Business Analyst Demographic Reports
A few maps & tables

4. Spider Line
Maps
Snapshot Data:
One Week of Checkouts

5. West Regional Library
Checkouts – Red Dots
Cardholders – Black Dots/Areas

6. West Regional One Week Snapshot:
78% in 10 Minute Drive Time
 One Week of Checkouts from West Regional
Library 1/08: 2464
 Number in 10 Minute DTP: 1928
 Percentage in DTP: 78%

7. Checkout Data: One Week Snapshot:1/21/08
West Regional Library,
Eva Perry, &
Cary Public Library

8. One Week Snapshot:1/21/08 with 10 Min DTP

9. NOR
10 Min
DTP

10. North Regional One Week Snapshot:
62% in 10 Minute Drive Time
 One Week of Checkouts from North
Regional Library 1/08: 4190
 Number in 10 Minute DTP: 2618
 Percentage in DTP: 62%

11. Buffer
Service Areas:
2 mile & 5 Mile

12. Compared Service Areas
Land Coverage: 10, 13 15 Min DTP
Library Drive Time Polygons - COUNTY LAND COVERAGE
13 Min DTP
10 Min DTP 15 Min DTP
Percent Inside Percent Outside Percent Inside Percent Outside Percent Inside Percent Outside
Current 56 44 75 25 84 16

13. Coverage Within DTPs - WRL
Total Households Percentage Total Households Percentage Total Households Percentage
Households with Card with Card in Households with Card with card in Households with Card with card in
Library within 10min within 10MIN 10min within 13min within 13MIN 13min within 15min within 15MIN 15min
West
Regional 24,164 20,318 84% 44,512 31,054 70% 59,820 39,633 66%
Coverage Within DTPs - NOR
Total Household Total Household Total Household
Household s with Card Percentage Household s with Card Percentage Household s with Card Percentage
s within within with Card s within within with card in s within within with card in
Library 10min 10MIN in 10min 13min 13MIN 13min 15min 15MIN 15min
North
Regional 60,164 34,650 58% 99,967 53,108 53% 134,608 66,478 49%
December 2008 Data

14. Discussion Item #2
Discuss possibilities
What are the options available to us?
What data would we need to make the best
options happen?

15. Possibilities
Query subdivisions/neighborhoods that are
underutilizing the library – Marketing
Campaign
Proximity: Shopping
Centers, Schools, Employment Centers, more
in depth transportation analysis

16. …more Possibilities
Comparing Drive Time thresholds for Regional
versus Branch Libraries
Comparing Drive Time thresholds based on
Square Footage

17. Future Service Area Possibility:
Area that contains a certain % of
Cardholders
Percentage consistent, shape different for
each library

18. Possibility: Further Grid Analysis
Refresh Data – Increase span of time series
Further study of areas of change
Relate these grid changes to Pop Grid
projections: 2010- 2025 (PDI study team)

19. Initial Cardholders
on the Map

20. Cardholder Density: Visualization of pattern/trend

24. Preliminary Grid Change over time Study
Increases
Wha’ Happened?
Increases

25. Discussion Item #3
Discuss process to create a production
database
What has been done in the past?
What could we do better?
How can we make it a regular process?

26. Cardholder Data Development
 2006:
 Geocoded by Lisa Sago
 Library Staff scrubbed Data
 Geocoded retail locations
 2008
 Geocoded by Carter Vickery with Jamaar Hosier & Alecia Medina
 Data Scrubbing by Carter Vickery with Jamaar Hosier & Alecia Medina
 Geoprocessed into Card Household Dataset using programmatic method to remove duplicates (Johanna
Foster, Carter Vickery & Jamaar Hosier)
 2009
 Geocoded by Carter Vickery and Jamaar Hosier
 Data Scrubbing by Jamaar Hosier & Carter Vickery
 Geoprocessed into Card Household Dataset using parcel methodology (Johanna Foster, Carter Vickery &
Jamaar Hosier: query by location using method for single family parcels & method for apt/condo, mobile
home park and institutional living parcels)
 2010
 Model to geocode
 Model to geoprocess into Card Household Dataset (use 2008 methodology w/percentage applied to
multiple dwelling records)
* Improvements in Address Locator and ArcGIS technology have improved the geocoding process – data can
now be imported as one file (.xlsx) and match rate is improved

27. Create a Production Database
Aggregate & Centralize geoprocessing outputs
FROM: TO:

28. Metadata - data about the data
- Viewable in ArcCatalog
- Metadata is a part of the data (associated xml)
SOURCE: Query (what does the data represent?)
Geoprocessing history
Initial record count, Geocode Match Rate

29. Geoprocessing Sequence
Step One: Geocode – Convert table of Addresses into points on the map

30. Optional: Library Scrubs Unmatched &
GIS merges with Matched

31. Step Two:
Geoprocessing to create dataset of Cardhouseholds
Feature to Point to Result: Card
Query Single Family
create one point per Households for Single
Parcels w/cardholders
Single Family Parcel Family parcels
Query record on
Result: Card
Apt/Condo, Mobile
Apply % to Dwelling Households for
Home
Unit totals (60% ?) Multiple Dwelling
Parks, Institutional
parcels
Living parcels
Merge: Single Family Final Result:
records + Multiple Card Households, Wake
Dwelling records County

32. Creating Production DB
1. Data Export
2. Geocode
3. ArcGIS Model of geoprocessing sequence:
Cardholder – Card Household
4. Analysis

33. Previous Analyses
Buffer vs DTP
Land Coverage with 10, 13 15 Min DTPs Maps
Table of area coverage of DTPs
Table of Households with card within DTPs

34. Development of Data
Process/Database
Improvement over time of geocoding engine
& process
Development of Geoprocessing Sequence

35. Applications
How can we deliver the
cardholder data & layers
to you?
Internal Flex app
ArcReader app
Other Possibilities
Map Service – Internal Access Only - WRL Checkouts: One Week Snapshot 08

36. Appendix: Cardholders to Cardhouseholds
Cardholders: One dot on map for each cardholder. Can be
multiple cardholders in a household.
Cardhouseholds: One dot per household that has one or
more library cards.

37. Potential 2nd Look:
Area of Loss 06-08
or Data Anamoly?

38. Results
Percentage with Card
in 10 min
Total Households Households with Card Percentage with Card w/ 8.04% Vacancy
06- 09
Library Within 10 Min within 10 min in 10 min Applied
Leesville 18,966 14,021 74% 81%
Athens Drive 20,537 10,682 52% 57%
Cary 29,762 18,521 62% 68%
Duraleigh 20,578 17,950 87% 95%
East Regional 9,927 6,787 68% 75%
EIC 9,337 3,659 39% 43%
Eva Perry 25,005 14,984 60% 65%
Fuquay Varina 10,231 4,753 46% 51%
Green Road 34,691 17,475 50% 55%
Holly Springs 11,947 7,492 63% 68%
North Regional 27,837 18,347 66% 72%
Richard B. Harrison 11,487 5,288 46% 50%
Southeast Regional 13,903 8,444 61% 66%
Southgate 8,814 4,949 56% 61%
Wake Forest 16,610 8,868 53% 58%
Wendell 3,698 1,987 54% 59%
West Regional 17,060 11,271 66% 72%
Zebulon 4,895 2,666 54% 59%
Cameron Village 15,166 7,407 49% 53%
Average in 10 Min DTP: Average in 10 Min DTP:
Total in 10 Min DTP 310,451 185,551 58% 64%
Total Countywide 363,730* 210,794

39. Population/Households
 Parcel Based Household Geoprocessing
2/22/08
Dwelling Units
ArcMap Relate:
 Join WAKE.PROPERTY with SDEDBA.APA on PIN_NUM
 Use records where APA.ACTIVITY < 2000
 Use Sum of APA.TOTUNITS (Not PROPERTY_A.TOTUNITS)

40. Results 06-09: Data Definitions & Caveats
 Population in table is from the GIS Parcel layer joined to APA table - Not an
official published number of Wake households. US Census Bureau estimated
339,756 Housing Units in Wake County in 2007.
 Household Data Source: GIS Parcel Layer joined with APA table
 Households with Card: Households who have used a library card 2006-2009
 Library Card Household Data - Potential for Overcount: 73,000
Apartment/Condo records
 Library Card Household Data - Potential for Undercount: Non-standardized
addresses (particularly College student addresses listed as dorms rather than
street addresses and addresses listed as institutions such as Athens Drive
HS, SAS, other schools)