Library Patron Density in San Joaquin County

This map was one of many maps produced to analyze the spatial relationship between library users and existing library facilities. The mapping process involved querying for all active library users from the library's patron database. The addresses from these patron records were geocoded to a street centerline coverage to create point locations. ArcGIS Spatial Analyst was used to create density surfaces from the geocoded patron address records.

The library used the map to show how the library users are dispersed throughout the county. Within each county community, the map helps identify potential future branch locations and/or bookmobile stops to provide ready access to patrons who may not be using the existing branches due to inconvenient location. A recently passed proposition by the voters of California made $350 million available in bond money for the construction of public libraries. The maps gave the library managers a graphic demonstration of the gaps in library facilities and aided in the application process for four new branch facilities.