The California Historic Resources On-line Information Center Locational Environment

By Matthew Syrett, M.A.
GIS Director, Central Coast Information Center

Introduction

As of the summer of 1993, there was no coordinated effort to develop a geographic information system (GIS) for managing the culture resource data housed at the eleven regional Information Centers run by the California's Office of Historic Preservation (OHP). This situation began to change during the 1993 Information Center meetings when William Seidel of the OHP met with Matthew Syrett of the Central Coast Information Center and talked about the potential for a future meeting to discuss the construction of a statewide cultural resources GIS. Next June, the staff of the Central Coast Information Center hosted a conference at the University of California, Santa Barbara to discuss a unified GIS for the Information Center system. That conference gave rise to the CHROnICLE (California Historic Resources On-line Information Center Locational Environment) project.

The importance of a unified effort in constructing a cultural resources GIS for California cannot be understated. The history of GIS is marked by countless examples of iniatives that have faltered due to their inability to merge their data successfully with the data contained in sibling electronic databases. These failures typically result from the shortsightness of not coordinating data standards with other databases that are being developed or already exist. The staff of the California Information Center system hopes to avoid this trap of database design by setting system-wide standards for data protocol, hardware, and software. This standardization will enable a seamless merging of the databases from all of the eleven Centers.

A Project Description

The term GIS describes a family of computer applications and hardware designed to manage and analyze spatial databases. A typical GIS stores information in the form of computer-rendered maps that are cross-referenced to a series of variables stored in a separate relational database. The relational database associates numeric or textual information to objects drawn on the maps. For instance, an object representing an archaeological site in a GIS map can be cross-referenced using a relational database to the age of that site, its location in reference to the nearest water source, or whatever variable the user desires. The type of GIS that the Information Center system has implemented is a vector-based system, which stores mapped data as a series of layers consisting of polygons, lines, regions, or points that represent real world objects. Each individual layer in the GIS describes the spatial location of a single type of mapped object (for example, topographic features, archaeological sites, or soil types).

The hardware/software platform chosen for the Information Centers GIS project is ArcInfo running on UNIX workstations. This configuration of hardware and software will enable the Centers to manage comfortably the many map quadrangles of data that will be entered into the system. ArcInfo does run on personal computers, but presently the PC version of ArcInfo is not fast or strong enough to handle the full complexity of the database that will be entered for California. However, since many of the Centers do not presently have the resources to develop UNIX-based systems, PC ArcInfo will be used in centers that cannot initially support a UNIX-based systems as a means of getting data entry and management started. Eventually, all the Centers will be running comparable UNIX systems.

The data entered at the eleven Information Centers will be collected and stored at a central hub housed at the University of California, Santa Barbara. The central hub will be a powerful Sun Sparc 20 computer. The hub will allow twenty-four hour access to the State database via the Internet. This level of access is crucial from the perspective of disaster management and effective day-to-day use by the others center. For centers or State agencies without access to an Internet connection, modem connections will be made possible.

The Santa Barbara hub will be created in cooperation with the Alexandria Project, which is a NSF-funded intitiative based at UCSB that is developing an electronic library environment for spatially referenced information. The Alexandria project will offer the central hub's clients a friendly and sophisticated interface for accessing the Centers' GIS database. In return, the hub project has offered itself and its data as a test case for Alexandria intiative.

Why do the Information Centers Need a GIS?

The GIS intiative will require a substantial investment by the Information Center system, so it is prudent to ask whether this expense is necessary. I hold that the answer to that question is that the expense is absolutely neccessary. Without a GIS to manage its increasingly complex database, the Information Center System will be unable to meet the management needs of the near future. The present manual approaches will soon result substantial inefficiency and even data loss unless new approaches to data management are implemented. This prospect is particularly true for urban areas of coastal California, where as many as 100 records can be cross-referenced to a single square kilometer of land. The maps of these dense area are becoming dangerously unreadable and very difficult to transcribe. The solution to the Centers data complexity problem is to improve the efficiency of its database management by implementation of a GIS.

The use of the GIS will have a series of benifits for the staff and users of the Centers. We understand the benefits of the proposed project to be threefold:

AS A MEANS TO IMPROVE DATA MANAGEMENT. A GIS will dramatically improve the day-to-day management of the Information Centers' spatial database. The problems of increased database complexity can be remedied by a GIS, which is by design capable of manipulating very complex spatial databases. In localities where the high density of data is making the physical USGS maps unreadable, the GIS will be able to sort out this complexity and prevent data loss. A GIS also will improve the speed of providing information to clients. A GIS query of the GIS database will take a fraction of the time currently required for users to manually look at the maps and access data on the mapped objects. Additionally, a GIS will improve the mapping of small parcel surveys (less than 0.2 Acres) and standing structure historic resources by the use of ArcInfo's address matching software.
AS A MEANS FOR INGRATING THE INFORMATION CENTER SYSTEM. The division of the Information Center system into eleven offices has fostered a good relationship with local preservation experts, but this benefit has come at the cost of coordination between the autonomous Centers. The GIS can lead to better integration between centers by integrating the databases being collected by the different centers, and setting firm standards across the system for the entry of electronic data.
AS A CUTTING EDGE RESEARCH TOOL. A GIS will provide the professionals who use the Centers with a powerful and accurate tool to do their research. Although GIS has existed for the last thirty years, this technology has only recently become accessible to researchers and archivists in the social sciences outside of Geography. There are two reasons for this delay, ignorance of GIS by many social scientists and the prohibitive costs of the building a GIS. This situation is beginning to change. Towards the close of the 1980s, GIS became widely recognized by researchers outside of the field of Geography, and, more importantly, the cost of building and using a GIS platform has come within the budget limits of the typical social scientist.
The accessibility of GIS since the close of the 1980s has attracted a growing number of cultural resource specialists interested in the analysis of complex spatial relationships. Although GIS applications are not yet prevalent in California, there would be a tremendous potential for research once the state's Information Centers have their data incorporated into a GIS. The proposed GIS would provide a platform for pursuing a variety of research problems concerning the management of historic resources in the California. For instance, a GIS will allow a comparison between the extent of survey coverage and number of sites found in the USGS quadrangles covering California. The limit of the system for analysis is limited largely by the creativity of the future user.

Structure of the System

The CHROnICLE GIS consists of three types of coverages: Archaeological Sites, Historic Properties, and Cultural Resource Projects. These coverages will all require different data tables. Each coverage will have two related files describing the objects depicted in the coverage: attribute tables that are referenced to spatial objects drawn in the coverages, and Look-up Tables that are referenced to the resource specific numbers (trinomial, HRI, and project numbers) of the attribute tables.

The following data standards should be used when generating CHROnICLE coverages:

The system will be based on the USGS 7.5' quadrangle system. Data will come into the hub as quadrangle areas. The completed coverage quadrangles will be linked into a uniform coverage for the entirety of California using the library functions of ArcInfo.
Site coverages will be represented as polygons.
Historic properties coverages will be represented as polygons mapped by address matching and manual digitizing.
Project coverages will be represented as an arc layer that will be transformed later into regions. Regions are new ArcInfo coverage objects that can link disconnected polygons into a single object. This option is unavailible in the PC version of ArcInfo.
The tic marks for geo-referencing the coverages will be placed at the four corners of the 1:24,000 USGS quadrangle maps and numbered using a Statewide numbering system.