Paper # 268
Joan Davenport, Supervising Planner
Tom Sellsted, GIS Senior Analyst
Back to Basics: Using ArcView 3.0
to Create a Public Query System
As a means of distributing
public information, the City of Yakima, Washington developed a user friendly
program to provide public access to geographic data and maps of property
within the Yakima Urban Area of Washington State. The application needed
to be dependable and 
minimize
staff resources to meet basic requests. The solution was to create a useful
and simple browsing tool using UNIX ArcView to access the wide range of
City of Yakima GIS data available in ArcInfo. Customization of the application
was accomplished using Avenue for presentation and to safeguard original
data.
The development of this program has
spanned the life of ArcView Versions 1.0, 2.1 and 3.0. Recent enhancements
to ArcView 3.0 which enables image libraries and other features have made
the public query system a viable program. This application has also been
piloted upon (and compared the development of) ArcView on each a PC, Macintosh,
and UNIX system. The end product is a browsing tool with intuitive operations.
The achievement of this goal required extensive Avenue programming to make
it look "simple".
INTRODUCTION
As a unit of local government,
the City of Yakima is responsible for providing public access to mapping
information. Much of the City GIS information is unique and is not available
from any other source. GIS staff resource time is very limited and precludes
serving public requests. While the requests for public information are
diverse, a majority of the public are interested, at any given time, in
a narrow range of data, often for a specific geographic location. Likewise,
many city functions also require quick, project level mapping information.
The development of a public access mapping station has been a goal of the
City for a number of years.
The promise of creating a truly user friendly public mapping system began
with the development of ArcView back in 1992. Bringing the power of ArcInfo
and all of the resident local data to desktop mapping meant "users"
did not have to be specialized knowledge of programming commands. However,
the limitations of ArcView 1.0 and 2.1 did not allow the flexibility to
create a functional and versatile public mapping station.
ArcView 3.0, released in 1996 contained functional improvements which have
facilitated the development of a successful public query system.
DESIGN CRITERIA
The public query system had to satisfy
a number of specific requirements in order to be successful. Many of these
issues involve perception of the user that the system is effective. Other
issues were strictly technical and not apparent to the user.
- Speed: At the top
of this list of criteria was response time or speed of displaying the requested
information. The UNIX based ArcView 3.0 version was selected with an X-terminal
display. Performance of this system was found to be significantly quicker
than the PC or Macintosh versions of ArcView. The size of the data used
for this project (20 gigabits) contributed to the poor response time with
NFS when data had to be localized on the PC. These problems were solved
with the UNIX based system.
- Current Data: Accuracy
of the information presented is also a principal criteria for the system.
The UNIX based solution also supported this criteria, which allows for
centralized, immediate updates of data which is distributed to all users
via the X-terminal.
- Independence: Users
of the public station needed a system which was easy to operate and did
not require significant staff intervention. Staff resource time is very
limited and does not allow for the staffing of the public system. It was
also considered important that the user felt confident in operating the
system. A colorful brochure was also developed for the user which provides
basic system tips and information.
- Reliability: To
the extent possible, the system should be "bullet-proof". As
an X-terminal, with direct reading of information, the public system needed
to safeguard original data from errant user problems. Likewise, the system
needed to minimize the opportunities for users to get lost or frustrated.
- Flexibility: Since
the users of the system have a variety of interests, flexibility was built
into the tools to meet individual needs. For example, several options were
constructed in order for the user to define the geographic area of interest.
Labeling and simple drawing tools were also enabled so that customization
of a simple map could be accomplished with the public viewing station.
- Quality: The public
perception should be very positive related to use of this system. Often,
quality is simply a function of ability to pay. Within the budget limits
of the City of Yakima, a high quality X-terminal was purchased. Hard copies
of maps are currently printed on the City high speed color copy/printer,
which produces very true color and high quality aerial photographs.
HARDWARE PROFILE AND CHOICES
The City of Yakima, Washington has been
an ArcInfo user since 1988 and has numerous well-developed data layers
on a broad range of municipal functions. Data management has been centralized
in the Information Services Division. All GIS coverages and data are maintained
and updated through a uniform system.
All ArcInfo data and applications are run from a DEC Alpha 2100 and distributed
to users via X-terminals. Necessity to distribute data to the public station
is similar to the needs of many existing users of the City GIS data. The
X-terminal UNIX environment ensured that the public station benefits from
all data updates and the speed of displaying and retrieving data is fast.
In 1995 when ArcView 2.1 was introduced, the City of Yakima purchased the
Macintosh and PC ArcView products as well as the UNIX version. Given the
City's centralized data system, support of the Macintosh and PC versions
of ArcView required use of NFS. Various versions of NFS proved unstable
and operation of ArcView on the Macintosh and PC were far from optimal.
Data retrieval times were very slow and NFS was subject to failure. However,
the UNIX version of ArcView was both quick and efficient in handling data.
Most X-terminal software runs native on a 17" monitor and users throughout
the City are upgrading equipment as necessary. The public query system
is displayed on a high quality 20" monitor (NCD HMX pro).
A QUICK TOUR OF THE PUBLIC MAPPING SYSTEM
This portion of the paper will provide
an overview of the public mapping station.
Welcome
Screen: The entry screen appears at the beginning
of each session and at restart prompts. You will notice the tool bar has
been cleaned to eliminate any other functions. Three choices are available
for the user to select the map area. Graphics for the entry screen were
created using a digital camera image, which was then enhanced using Adobe's
PhotoDeluxe' software.
Address: Clicking this button will present a pop up window
for you to enter an address. Enter the street address and click the OK
button or hit the Enter key. A parcel map of the area will be displayed.
You may also enter an intersection as an address (such as S48th Ave &
Tieton Dr).
Addresses and street locations requests require an indexing of the street
coverage to find the appropriate location. Since the address matching is
not perfect, but can estimate the site location, the viewer is presented
the general location of the request.
Location: The Location button will display a map of Yakima.
Once displayed, you may use the mouse to point to the area of interest.
A parcel map will be displayed for the area chosen.
The ArcView application zooms to an area of an 800 foot perimeter centered
around the point of selection. The viewer can then pan or zoom to be more
specific.
Parcel: Choosing this button will pop up a window asking
for an Assessor parcel number. The user must enter a valid eleven digit
number. A parcel map will be displayed with the selected parcel highlighted
as the subject area.
If the user enters an invalid parcel number, a message is returned requesting
a the user to enter another parcel number or return to the welcome screen
for another choice.
I've
Got a Parcel Map, Now What?
The basic parcel map appears when the user
has selected a geographic area of choice. The user is presented with a
customized View GUI which provides mapping options.
The View GUI is loaded with a basic set of buttons, as well as a series
of pull down menus for the user to refine their query. The user has the
choice of using the pull-down menu or the icon buttons, depending on their
level of comfort. The map legend lists all the features on the screen.
Other
Map Views
Once the user confirms the location of choice,
a series of other map layers (themes) are available for viewing. These
themes are protected in the order of items which are displayed. The viewer
may choose to "turn-off" some item listed in the map legend,
but they cannot change the order in which they draw.
The
user has the option of displaying one of seven themes for the subject area.
These thematic maps are the most commonly requested geographic features.
Choices for display include: Parcels, Zoning Aerial Photo, Future Land
Use, Critical Areas, Utilities, Soils and Contours. The ability to view
and print copies of the aerial photos for project sites has been the single
most popular feature for the public and other City staff who are not GIS
programmers.
Support for the image catalogs was a significant enhancement with ArcView
3 which has vastly improved this application.
Modify the Map Area
Several basic buttons have been enabled to
allow the user to change or modify the map area of the view. The primary
premise of the public station was to keep the operation very simple. With
use of the View GUI icons and feature text, the zoom in, zoom out and pan
options are intuitive and provide the user basic flexibility.
When a user changes the extent of the view by pan or zoom, all subsequent
themes (zoning, utilities, etc.) retain the new map extent until the user
restarts the program by changing the selected area.
Information Tools
While the user cannot perform analysis on
the map or screen created with this ArcView application, two basic information
tools were enabled. The identify button and the measuring tool have been
included in order to provide query functions.
Printing
The public station was specifically designed
to prohibit the user from saving their work. A simple command to print
the current view can be issued by clicking on the printer icon or by using
the pull-down menu.
A customized template was developed for this program, rather than using
the default map layouts created by ArcView. A standardized format was necessary
for this project which displayed appropriate titles and legends. The hard
copy maps printed by the user had to be predictable and look uniform even
though different themes utilized various information.
Only one map template is currently available to the user (an 8.5 by 11
inch landscape template). Users are charged $1 per page of printed material.
Customizing the Map
The public viewing station is intended for
quick reference. It has served this purpose very well for many citizens.
Additionally, city staff from various divisions have used this program
for rapid access of information. Often these "in-house" users
will need to customize their map product. The view bar includes basic drawing,
labeling and text tools.
Adding this functionality to the basic program provides the "in-house"
users the ability to prepare a finished product which meets specific needs.
The tools menus enabled for this use include the color palette, Draw Tool,
Font Palette and Text tool. Additionally, the Label Tool has been enabled.
WEB-SITES AND OTHER FUTURE OPTIONS
ArcView 3.0 provides a very flexible tool
to construct customized application. Further refinement of this core program
will likely be a continuous process, evolving as user needs develop. A
number of enhancements or modifications to the existing public viewing
station program have been discussed.
User selection of themes from a list, with the ability to select additional
features;
Additional printing options to include other templates and a one page,
four map atlas;
Hot links to other images such as plats and assessor maps.
The City of Yakima, Washington is in the process of establishing a City
Web site for public information. We will explore porting this application
to the internet along with other information.
Acknowledgments
We would like to acknowledge Ira Waxberg, who as a summer intern
in 1995 helped explore the feasibility of this project using ArcView 2.1
on the PC. Special thanks to Jill Ballard for never-ending maintenance
of GIS coverages.
End Notes
For copies of any of the Avenue scripts used in this project, send
an email request. As a post script note, we are hopeful that more specific
and descriptive examples will be added to Avenue Help in future revisions
of the software. Often the Help explanations are cryptic, error messages
are also not descriptive enough to diagnose the problem.
Author Information:
Joan Davenport, Superivising Planner
Tom Sellsted, Senior GIS Analyst
City of Yakima, Washington
129 North Second Street
Yakima, WA 98901
Telephone: (509) 575-6164
Fax: (509) 575-6105
email: tsellste@ci.yakima.wa.us