County Engineers Develop GIS-driven Community Rapport KENNY GLOVER

It wasn't what Mobile County Engineering Department (Mobile, Alabama) employees expected or even planned for. Their job description had always been clear: manage Mobile County's roads, assign addresses, and support 911 activities as best as possible. That description still holds true -- with a few added responsibilities.

With the implementation of an enterprisewide GIS, that job now reaches into the heart of the community. The same information used to manage roads is now used in courts, on school boards, for census mapping, to manage disaster response, for watershed analysis, and for numerous other community-associated activities.

The department now provides geographic analysis and land-planning summaries for the County Engineering department, the city of Mobile, Mobile Gas Corporation, Mobile County Sheriff's Department, Mobile County E-911, the city of Bayou La Batre, and the state of Alabama, to name just a few. Each entity uses maps, charts, and analytical studies created from the Modular Geographic Environment (MGE, Intergraph, Huntsville, Alabama) GIS software running on a Microsoft Windows NT operating system by way of a PC and Intergraph InterServe 630 server-based network. Primary data sources include U.S. Geological Survey quad maps, property tax maps, aerial photographs, and 1997 countywide digital orthophotos with 3-foot contours.

"We've become the data warehouse for Mobile County," said Joe W. Ruffer, Mobile County's director of Public Works and county engineer. "We continually strive to strengthen our relationship with other government agencies and our community to better support various activities. In so doing, we've managed to save hundreds of thousands of dollars [and] an enormous amount of time and, in some cases, [we] do our part to ease suffering during natural disasters."

Hurricane watch

On July 19­20, 1997, Hurricane Danny, a category one storm, parked itself directly over Alabama's Mobile Bay. The hurricane brought with it winds measuring more than 70 miles per hour, and nearly 40 inches of rain fell on the coastal communities of Mobile County. Flooding brought travel to a standstill, cut most power sources, and left many people homeless. Speed is everything in these situations. The Mobile County GIS helped dispatch information to necessary emergency groups in a matter of hours. Analysts scanned Doppler radar composites showing the total rainfall amounts into the MGE database to calculate rainfall runoff in the county. Then the analysts used the existing address database to calculate the total number of households affected by flooding. By overlaying these core pieces of information on top of each other, emergency crews could quickly assign teams to help the hardest hit areas. The department also provided hurricane evacuation routes and maps to state troopers.

The Engineering Department learned some valuable lessons during this experience that set the foundation for future support efforts during similar disasters. Mobile County's subtropical environment brings with it a certain amount of instability, particularly during the summer months. As a community Mobile County must be prepared to respond quickly during such events. One year later, on September 28­29, as Hurricane Georges gathered energy off the coast of Alabama, that preparation proved invaluable. The hurricane left behind 20 inches of rain. More than 100,000 people suffered from power outages, as many as 1,884 residents were forced out of their homes and into shelters, and major highways and airports were closed for several days. Before the rain subsided, GIS analysts mobilized once again to build the necessary maps and reports to support emergency crews and citizens.

GIS in the community

Fortunately, disasters are infrequent and the Mobile County GIS experts can spend the majority of their time supporting some of the more ordinary activities in the community.

The Mobile County Commission and the Mobile County School Board first brought GIS distinction to Mobile's local government community in the form of redistricting. The County Commission first challenged the GIS group to redraw the County Commission boundaries based on the 1990 census. This task proved fairly straightforward, given that most of the address information was readily available on the system. The school board redistricting proved to be slightly more challenging but worth the effort.

In the past, redistricting involved hiring an outside agency to map the area, which was expensive. It just didn't make sense. The Engineering Department had all the core baseline information already stored in its GIS to perform this study -- all that was needed were the digital census data. Once the census data arrived from the Bureau of the Census, the Engineering Department simply needed to merge two data sets using intrinsic analysis tools to calculate population totals by district.

It took about three months to complete that first time and saved the school board around $200,000. The department has learned a lot since then and expects to do the same job in about half the time after the 2000 census.

Flood plain data. GIS analysts moved on from this experience to flood plain management. Thanks to GIS technology, Mobile County is one of the few counties in Alabama to employ digital flood maps for flood plain management. A few years ago, the GIS team scanned and digitized more than 50 of the flood insurance rate maps for Mobile County into their GIS.

Now when a citizen applies for a building permit, Mobile County Inspections Department staff can locate the lot in question, overlay the flood plain data, and check the property boundaries. If the property is in the flood plain, the permit officer can quickly determine the base flood elevation and define building limitations for that piece of property. The department used to do this same job using paper maps and a pen. Now the maps are so current that the Federal Emergency Management Agency uses Mobile County's base maps to generate its digital flood maps.

Watershed efforts. Just recently, the Engineering Department moved into watershed analysis for the Environmental Protection Agency's Clean Water Act. Some examples of this effort are: water quality sampling, illicit discharge enforcement, quantifying land use (calculating runoff quantities, establishing stormwater controls), and associated educational activities. This area of concern is crucial to the county because Mobile hosts one of the nation's largest ports, with a channel depth of 36 feet and a width of 400 feet. The port ranks first for wood pulp exports and second for forest product exports nationwide.

Mobile County must carefully monitors the pollutants in stormwater. Data from stormwater samples are applied to the outfalls in the watersheds to arrive at an estimation of event mean concentrations -- the concentration of pollutants in a typical storm event -- of pollutants and annual pollutant loading in the watersheds. Once again, the information is recorded in the GIS database as it is gathered in the field. Using GIS technology, analysts can easily prepare various watershed reports and check progress in areas of concern.

The department has also helped the Mobile County Emergency Management Agency plot the locations of emergency sirens at county-based chemical plants. These sirens would be activated in the event of a chemical-related emergency. Ideally, EMA hopes to electronically link the siren activation process to the geographic maps. During an emergency, an EMA operator could trigger the siren transmitter by clicking the symbol of the siren on the map.

More recently, GIS analysts have helped the Sheriff's Department crack down on drug trafficking in school zones. These maps highlight areas within a three-mile radius of every school in Mobile County. Officers carry these maps on the street and in the courtrooms to support criminal convictions.

And finally, the public can take advantage of this digital data as well. For a nominal fee citizens and private enterprise can also purchase maps or even the digital data to create the most current address and road area maps.

What about the roads? 

Amidst all of the other activities, the Engineering Department is responsible for maintaining 832 miles of paved roads and 543 miles of unpaved roads. The management of these roads gave engineers their first glimpse at the power of GIS as an analytical and management tool.

Engineers use the GIS to keep records on road project details such as total labor-hours, fuel, and equipment costs. The analytical tools built into the GIS, such as MGE Analyst, allow engineers to explore different scenarios. For instance, engineers might seek out all dirt roads in a particular maintenance area that exceeded a specific budget, or perhaps a list of all roads in a particular maintenance area scheduled for work in the next three months.

Sign inventory. Another important GIS engineering function is the sign inventory program. Using Trimble Navigation (Sunnyvale, California) DSM Pro differential GPS receivers, county traffic maintenance crews position the location of traffic signs throughout the county. They also take digital photographs of the sign and surrounding area. This information is vital in the defense of lawsuits involving traffic accidents. If needed, the department can produce evidence that a particular road sign was in place and in good condition at the time of a particular accident.

In terms of address mapping, the Engineering Department is in charge of tracking all county-issued building permits. A simple analysis of existing data combined with the base county map offers an extremely visual map of construction trends and population growth.

911 benefits. Even 911 will realize the benefits of this system very soon. Currently the Engineering Department provides the core centerline road file and address ranges for 911 by way of electronic and paper-based media; however, 911 management is in the process of implementing a new automated, GIS-driven 911 dispatch system that will work like this: When a call comes into the 911 center, dispatch software automatically searches the address of the caller based on phone company records. If there is an exact match on the address, that point is displayed on a GIS map. If the system does not find an exact match, it interpolates the location of the call based on the address ranges and displays that location as well. All this would be done in seconds and give the dispatch operators an extremely visual information base to share with emergency crews on the street.

Though it is not yet implemented, a T1 line connecting the Engineering Department GIS directly to the 911 dispatch office will update that system bimonthly or more frequently when necessary. The system is estimated to be complete by fall 1999.

These and many other similar projects hold the key to continued growth of the GIS to support local government, citizens, and even those organizations at the state and federal level. "It's our goal to keep building communication and information links with all facets of our community," Ruffer said. "We are only limited by our imagination in the directions that this valuable technology will take us."

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