As GIS technology continues its diffusion throughout the
County, an increasing amount of Information Technology staff time is being
devoted to supporting the expanding network and installed user base. Included under the
technical support umbrella are responsibilities for system administration, database administration, documentation, data distribution, end-user consultation and training, and application programming.
System Administration includes tasks such as installing new
software and upgrades, managing user accounts
and hardware devices, performing systematic
back-up of all file systems and on-demand data restoration, configuring new hardware
devices, monitoring connectivity and processing for maximum efficiency, managing
application licensing and print queues, and troubleshooting problems.
Operating system and application software upgrades must be
managed carefully because each brings with it enormous change. Users benefit from new
features and enhanced functionality but they suffer the pains of installation and
reconfiguration. Routines that previously worked flawlessly sometimes no longer work at
all. Programs and procedures must be modified accordingly.
Each new user and device added to the network has an
impact. The integration of PCs into the GIS network presents a particular challenge. Each
PC possesses a unique hardware/software configuration that must be evaluated for its
ability to run GIS software. A review of other software applications currently installed
and drives being utilized must be performed to avoid conflicts with Novell LANs. Finally,
the PC memory must be optimized for efficiency, installed software tested to ensure it is
trouble free, and attached peripheral equipment checked for connectivity.
The County's GIS data are stored in a central database
residing on the ArcSDE
GIS Database Server. Thus, any user on the GIS network may view countywide
geographic data from a common source. This centralized "data warehouse" provides an
efficient and secure means of maintaining the GIS data.
Centralized database administration using ArcSDE makes
GIS information readily accessible online for query purposes to all users on the network. Each data layer may be easily updated by its owner
but is protected from inadvertent change or deletion while in the hands of a casual user.
The data are more available while at the same time more protected than ever before.
One of the most important and often overlooked aspects of
keeping a system running is the documentation of the database as well as system
The GIS Data Dictionary provides documentation on
all datasets housed in the central GIS data warehouse. Designed to assist the user in navigating
through the GIS database, it includes links to metadata for each layer in the database.
A layer bibliography and a detailed
description (metadata) of each individual data layer comprise the bulk of the document.
System documentation is thorough as well. Subsequent to
each hardware and software upgrade, system administration procedures are checked and
updated as required. System documentation also includes daily operational procedures such
as the methods to monitor print queues and system processes, problem resolution logs,
backup and restore logs, and system guidelines such as adding and removing users or
equipment to the network.
Many federal, state, and local agencies as well as private
sector parties seek data from Volusia County. A number of partnerships have been developed
whereby data have been freely exchanged among agencies. Municipal datasets have been
provided to Volusia County cities initiating their own GIS programs. This gives these
communities the opportunity to jump start their own GIS programs with the data provided
and allows data standards to be established which will ensure compatibility between County
and City systems.
With the variety of software packages in use, and the
disparate data formats and media types being employed, data transfers require
coordination. Meetings are often necessary to determine the types of data required and
appropriate transfer methods. Data distribution involves a variety of tasks including
clipping datasets to conform with the specifications of the requestor, conversion to the requested file
formats, determining file sizes and calculating prices where applicable, copying the data
to disks or tapes, and follow up customer contacts.
In an effort to streamline the data distribution process,
Volusia County makes its digital data available for download over the internet.
I would like to Download
As the GIS program matures, several classes of users are
emerging. They range from staff members employing GIS for a single function or repetitive
task, such as address matching customer service calls, to professionals using GIS for
sophisticated analyses. In addition, there are "power users" and automated
mapping personnel within certain service groups which require GIS support. Further
complicating the issue is the variety of hardware and software options available to users
on the GIS network. Each class of user and each hardware/software combination requires a
different type of support and levels of expertise. For this reason, each user group is
assigned a GIS staff member who can become thoroughly familiar with the hardware
configuration and application requirements of that particular group. This relationship
allows the GIS Activity to provide better service to its customers. Regardless of end user
assignments, GIS staff members must maintain a broad based knowledge of hardware issues,
ARC/INFO and ArcView software capabilities, and data sources from both within the County
and outside agencies.
I Would Like to Learn More
About the Basic Concepts of GIS
I Would Like to Download
ArcExplorer and Learn How to Use It
I Have Bought ArcView and
Would Like to Learn More About Using It
ArcView can be customized and applications automated with
Avenue, ArcView's programming language. In one such program written for the Growth and
Resource Management Department, the user is only required to input a valid parcel number
and select the layers of information desired; such as flood plains, zoning, vegetation,
soil types, and future land use. The program selects the parcel from a countywide basemap
and performs what is known as a spatial overlay analysis.
In this process, the program goes to the GIS library for the layers selected by the user
(zoning, vegetation, etc.) and determines which category or categories (residential, pine
flatwood, etc.) exist in the same spatial area as the selected parcel. The information
from these data layers is then displayed in an easy-to-read report and overlaid onto the
map for drawing.
The program shifts through approximately two gigabytes of
data to identify the parcel and to do the overlay analysis. This process takes only a few
seconds, thereby saving the user a tremendous amount of time. This is an important
consideration, given that the target audience of this program is the county's customer
service personnel, who often have to answer questions for taxpayers over the telephone.
Another area of concentration for GIS programmers is that
of internet-based mapping applications. Currently, Volusia County GIS is working on
several such projects using ArcIMS
HTML, XML, SQL, etc.
Links to Internet Mapping Applications:
Appraiser's Mapit (A function of the Property Record Search)
Management Zoning Search Application