Appendix H

Appendix H: Library Service Areas

Experience has shown that each library has a geographic area it serves. Fresno County Public Library contracted with Dr.Christie Koontz, Director, GeoLib Program, Florida State University to conduct this study which produced service area maps and provided projected population data.

The text of Dr. Koontz's report follows.

Criteria for Estimating Geographic Branch Market Areas


In today's world, estimating the geographic market area *8 and developing a profile of the people with the area to be served, is the first step in any type of location analysis for siting, closing, or merging any service area. Determining the market area is problematic and several approaches are offered in the library field including: 1) have branch librarians agree from experience, on service area lines, acknowledging traffic patterns and/or travel time and U.S. Census tract lines and population totals; 2) utilize local government planning areas that may roughly coincide with library service areas such as census block *9 groups or traffic analysis zones; sample registration or circulation records, plotting residences on large map. *10

Each of these approaches have advantages and disadvantages. The experience of branch librarians may not include valuable library research data, or up to date U.S. Census and library user data that would be reflected in a more systematic data-based approach. Utilizing government planning areas assumes people do not cross over legal lines daily, for many and sundry purposes. Registration data only reflects where people got their library card. Circulation data identifies patterns of use for each branch, but only reflects what materials people checked out of which library. This eliminates all types of in-library use, and growing offsite use.

While no method is flawless, a combination of these methods is effective when carried out in a systematic way.

Requirements of the Study from Fresno County Public Library to GeoLib

In order to fulfill the requirements of the GIS Branch analysis study, the registration user address data of users was plotted for each of 31 library branches, and the Talking book Library, as well as the bookmobile.

The following library branches were plotted individually and in groups, on full-scale maps, with coloration to depict user address, library location, major topographical features including:

a) Auberry, Shaver, Big Creek, Clovis
b) Bear Mountain, Miramonte, Reedley, Orange Cove, Parlier
c) Central
d) Sanger, Piedra, Sunnyside, Parlier
e) Selma, Fowler, Kingsburg, Laton
f) Riverdale, Caruthers, Easton
g) Tranquillity, San Joaquin, Mendota, Firebaugh, Kerman
h) Politi, Fig Garden, Pinedale, Clovis
i) Ivy, Mosqueda, Central, Sunnyside
j) Cedar Clinton, Gillis
k) Talking Book Library for the Blind (four county service area)
l) Bookmobile

Advantages and Disadvantages of Using Registration Data to Plot Geographic Market Area

1. The registration data is limited in that it only illustrates which library users registered at which branch. This indicates several plausible assumptions (not an exhaustive list, but rather illustrative) that can be made regarding the advantages and disadvantages:

1) Advantages:
a) the library branch is convenient in perception or reality for the user and therefore used often;
b) the library branch communicated a service or product of need or interest to the user, the user registered, and the branch remains a positive choice for that user’s information needs;
c) the registrant has transportation to the branch, or lives within walking distance, and therefore, continues to use branch on a regular basis;
d) the branch may have a special collection or service that originally drew the
user there to register for library services, and the user continues to use this branch.
2) Disadvantages:
a) the user only registered at this branch and uses other branches;
b) the user only registered at this branch and never used any library branch again;
c) the user submitted a post office address, rather than a street address and could not be geo-coded.

While these are not exhaustive, these do reflect the limitations of only using registration data to determine geographic market area.

Recommended Methodology for Fresno County Public Library Branch Analysis Study

After plotting the individual libraries’ registration data, and then in the specified groups of libraries the following review and analysis should be conducted:

  1. Review the patterns of the plotted data by branch and branch group. This data will be plotted over census tract/block groups lines.
  2. Review old ascribed branch service areas.
  3. Assign preliminary markets based upon plotted registration data.
  4. Identify topographical boundaries that delimit physical access such as railroad tracks, large highways and rivers, industrial and commercial sights.
  5. Estimate distance between library facilities (still considering the topographical barriers);
  6. Review square footage and hours of operation of each facility to better describe the ‘drawing power’ of each of the branches.
  7. Review library use statistics for each branch over the past few years.
  8. Estimate population around each library facility in specified increments, e.g., urban .5 to 1 mile, and rural 2 to 5 miles.)
  9. Review the patterns of the plotted data by branch and branch group again.
  10. Ascribe preliminary geographic market areas to branches.
  11. Review the requested demographics (in table form from US Census 2000) including: population (and population projections, estimated on Traffic Analysis Zone boundaries and acquired from FCOG); age groups; race/ethnicity; households with children; urban setting. After discussion some of this demographic data can also be plotted on the maps with certain conditions such as census tracts with over 25% household with children 0-18, if staff time is available and within budget.
  12. Make final adjustments and ascribe branch geographic market areas.

At present this is all the data available for this analysis, coupled with the experiential advice of Fresno County Public Library staff. This approach to determining geographic branch market areas encompasses activities of recommended approaches, excluding mapping circulation data which will provide more precise customer descriptions for each branch.


Geographic market areas of branches should be reviewed when:

  1. A branch is opened or closed.
  2. Dramatic changes in relevant population characteristics.
  3. Changes in neighboring community.
  4. Changes in proximate topography.
  5. New data is available that may affect understanding of the use of the library branch, i.e., survey or focus groups data, secondary data from other sources.

Upon completion of these steps, the following service area maps were produced for each library. Ten Regional Maps combining several service areas were also developed and are on the following pages.

*8 A market area is a geographical area containing the actual and potential library users of a particular library for specific goods or services.
*9 Blocks are the smallest of the census geographic designations. These are roughly equivalent to a city block and provided for areas lacking census tracts. Block groups are sub units of census tracts, typically having 1,000 residents. Census tracts are largely homogeneous and have 4,000 to 8,000 people.
*10 Nancy Van House, et al 1987. "Output Measures for Public Libraries," prepared for the Public Library Development Project, 2d ed. Chicago: American Library Association, pp 35-36.

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