GIS blazes a trail in fire management
August 1991: A Nevada homeowner on the north shore of Lake Tahoe reports a wildfire in the First Creek drainage area. Within two hours, the fire has burned 582 acres and more than 120 homes, despite air support and rapid response from nine fire-fighting agencies. Fortunately, that fire was only a computer simulation used for research and public education. By all accounts, however, the possibility of a large-scale fire in the Lake Tahoe Basin is very real. Past logging, which allowed brush and immature trees to proliferate, along with an aggressive fire suppression philosophy that prevented their removal, have created a situation ripe for disaster.
The scenic Lake Tahoe region features a mix of dense forest and even denser development on steep slopes. The resort community of Incline Village on the lake’s north shore has for many years pursued a program of “fuel” reduction around development — fuel meaning anything flammable.
To aid in developing fire management and prescribed fire planning, the Lake Tahoe Basin Management Unit of the U.S. Forest Service (USFS), along with a number of other federal, state and local agencies, is using GIS-based data. According to Mark Johnson, the USFS’s fuels specialist, fuel models based on satellite imagery are combined with hazard, risk and values factors, digital slope models and vegetation layers in a GIS. >From plotting areas to be burned with aerial imagery to determining the path of natural fire destruction with fire simulations, GIS helps users better determine fire-rescue plans, safely employ prescribed fire techniques and easily communicate information to the public and government agencies.
GIS to the rescueAs part of the GIS-based Regreen project, the cooperating agencies can use satellite data to determine jurisdictions for fire management. Pete Anderson, resource program coordinator for the Nevada Division of Forestry (NDF) says the ultimate goal of Regreen is to reduce the danger of “the big one” and to implement technology transfers from public agencies to private landowners for risk reduction and revegetation activities.NDF and USFS also are surveying state lands in the basin and along the eastern Sierra Front to create a comprehensive inventory of forest health, using permanent ground plots that are positioned for entry into the GIS. Dead and dying trees are followed through time to track trends in forest fire conditions and tree mortality. The GIS data eventually will be used for pre-attack planning and actual fire fighting.
GIS systems can assist with prescribed fires and fire management, but anyone who has struggled with integrating remotely sensed and ground data into a GIS project can well appreciate the difficulties and complexities of such a project on the Lake Tahoe/ Sierra Front, where technology is not widely used. “GIS is our most powerful tool for information display and analysis, but it has a steep learning curve,” Johnson says. “You need a technoid man or woman on staff who does it full time, and most of us don’t have that.”
Controlling the flames While intentionally set fires have been used in rural areas throughout the region to clear brush and reduce fuel loads, their use in high-value, high-risk developed areas requires special attention to ensure that they burn in predictable and controllable ways. Prescribed fire recently has been added to Incline Village’s management program, and each winter a multi-disciplinary team develops a burn plan for the fall season.
Throughout the summer, the selected burn sites are prepared with fuel breaks by clearing around “keeper” trees and thinning brush. A detailed fire prescription and a “go/no go” checklist determine the actual burn date.
About 40 to 50 acres are treated annually, in 2- to 12-acre patches through the town’s greenbelt. Intense public awareness and education campaigns have garnered widespread support for the program.
To assist with fire control and management, the Sierra Front Wildfire Cooperators, a coalition of federal, state, tribal and local entities with fire suppression responsibilities along the eastern Sierra Front, is now collaborating with the University of Nevada, Reno. The groups are working to implement fuel management (including prescribed fire) and land use planning with the goal of saving lives and reducing property losses from wildfire. Specifically, project goals include the use of GIS-based wildfire fuel models for major eastern Sierra fuel types; validation of wildfire computer simulations; development of prescriptions and ordinances to reduce fire threat; monitoring the adoption of pre-fire threat reduction activities; and communicating the information to agencies and the public. At the university, Paul Tueller, a professor of range science and remote sensing, and his students relay information to a variety of users in land management, fire and defense agencies. Users can obtain solutions or discuss problems related to natural resource mapping, fire research, big game management, disturbed-land reclamation and a host of other issues that can be addressed through GIS and remote sensing.
Through Tueller’s program, satellite imagery, airborne videography and aerial photography are integrated with GPS data in a GIS. The GIS classifies fuel types and fire risks and allows simulation of fires within the project for planning and risk assessment. Additionally, student Karl Krauter has developed a fire hazard map based on elevation, slope and fuel type for the Carson City area and is expanding it to the rest of the Sierra Front.
The hazard map is of great interest to many agencies in the region. In fact, a Carson City ordinance relates zoning and fuel reduction requirements to such information, but until creation of the map there was no way to implement the law.
Fire agencies will use the hazard map for pre-attack planning, fuel management and other prevention functions. Krauter also is testing a fire behavior simulation software program against past fires in the area, and he is simulating different fires to show the potential for problems and how they can be prevented.
The simulation, called Farsite, predicts fire behavior across landscapes using five data layers: forest canopy cover, elevation, aspect, slope and fuel model, along with wind and weather text files. It operates on Redlands, Calif.-based ESRI’s Arcview/Spatial Analyst GIS platform to “run” fires with differing topography, weather and fire response plans. While the program originally was developed to support prescribed fires, it increasingly is being used in planning and public outreach. “It has huge implications for education,” Krauter says. “It’s very graphic — you can show someone their house and say, ‘Now let’s start a fire here today under the current weather conditions — oops, sorry! There goes your place!’ There are also big advantages for pre-attack work; you can test fuel breaks and reductions without actually doing them and burning them.”
Simulations can further aid efforts to determine a potential path of destruction by fires. Assistant State Park Resource Ecologist Esther Mandeno uses GIS to model fire in the Tahoe area parks, including Sugar Pine Point State Park on the southwest shore of Lake Tahoe, where she works with the California Department of Parks and Recreation. GIS enables her to identify areas for prescribed burning, varying the wind and weather text files to determine the best conditions under which to burn.
Mandeno also uses Arc/GIS to design trails, plan logging road rehabilitation and evaluate the results of her extensive prescribed fire activities in state parks throughout the Sierra district. Inventories of soil layers, vegetation layers, archaeological and historic sites, and fire and water monitoring plots all go into the system, as do wildlife sightings and osprey, spotted owl, and goshawk roosts and nests.
The fire history and prescribed burn layers in Mandeno’s GIS include attribute tables of fire behavior, rate of spread, flame length, flame base, depth of flame front and weather. Before and after photos of burn sites are also linked. The fire monitoring data — including tree density, species, mortality pre- and post-burn, herbaceous cover, shrub density and fuel load — is linked to GPS points at the plot center. Individual tree char heights, scorch heights, scorch percentages and burn severity indexes also go into the GIS. Approximately 200 acres per park are burned each year.
Coming out of the ashesPublic ignorance of the benefits of controlled burning is a serious problem. To further public education, the Minden, Nev.-based Sierra Front Wildfire Cooperators organization is planning a “Living with Fire” conference in Reno this year. Its purpose is to bring controlled burning to public, political and corporate attention. The Farsite simulations, along with fuel hazard maps, are a dramatic component of the education effort.
The majority of fire safety information is directed at local and regional managers and homeowners, but insurance underwriters also may want to examine the data. Krauter says that, once his hazard map is completed, it is likely that insurance companies will use it to rate risks for policies on an individual basis, perhaps incorporating other GIS layers such as access, water supply and other elements.
Clearly, using GIS-based data for fire threat assessment and strategic planning can help cities and counties better manage and control wildfires in high-risk areas. The simulations used in projects such as Farsite further promote safety in planned fires and assist in controlling and predicting spontaneous wildfires.
“This is one of the most inclusive and widespread issues in our society and environment,” says the University of Nevada’s Smith. “It is like a chronic low-grade infection — when it flares up, there is big trouble.”
Lack of funds prevents many local government projects from coming to fruition. However, in several Indiana counties, GIS implementation is being achieved through an incremental process involving numerous small, low-cost projects.
In 400-square-mile Marshall County, officials are approaching GIS with component projects and a flexible five-year budget. “Our strategy was to break the project into segments, and, if funding was not available, we would at least have a finished phase to build on,” says Marshall County GIS committee member Ralph Booker. Begun in 1994, the first phase established GPS survey control points. Future GIS “pieces” include expanding hardware and software resources and the acquisition of data such as roadway information.
“It’s GIS by bits and pieces,” says Allen County, Ind., GIS Coordinator Bob Lee. He expects that Allen County will set aside $200,000 to $400,000 annually to support incremental GIS growth.
The county has completed an extensive survey project and makes points available to local surveyors and engineers. The points also were the framework for the second piece of the county’s GIS plan — aerial photography. According to Lee, there are daily requests from the public for aerial photography, which will be used as a GIS base “layer,” along with other planimetric data.
Local governments that have successfully implemented GIS recommend several steps: * Plan and re-plan. Use GIS consultants to investigate potential GIS benefits as well as to help identify and estimate costs. Revisit the plan as the technology and the needs of the county change. Gordon says the Allen County committee reviews priorities on an ongoing basis. * Get people involved. “Individual and group interviews really got people thinking and, surprisingly, additional benefits were identified,” notes Larry Fisher, Marshall County surveyor. It is important to seek input from prospective GIS users, including elected officials, in order to understand how the system should work, secure public support and help set realistic expectations. * Use early successes to help sell the value of the system. “Take what you’ve got and do something with it,” Lee says. Even small successes can be used to show the value of a GIS. * Be flexible. Although there are schedule tradeoffs, as a cost-saving strategy Allen County is using a mix of in-house staff and GIS service providers to build the GIS. Find a provider that can meet the schedule and the budget, Booker suggests. However, he adds, “Not every firm out there will allow you to spread costs over several years.” * Be patient. “Patience is a virtue when building a GIS incrementally,” Gordon says. “Some governments ask, ‘How much will a GIS cost?’ For the rest of us the question is, ‘How patient do we have to be to pull this off?'” * Finance the project with a “basket” of funds. Lee first created a list of county funds then determined likely candidates for GIS support. “That way, county officials can be alerted as to potential sources,” Lee says. In Allen County, officials have tapped departments with discretionary funds, the County Economic Development Income Tax, and E-911 funds.
Because a GIS can be built in stages, it offers an advantage to local government users with limited funds. By devoting small amounts of money and effort toward building the GIS, governments can establish a strong foundation and gradually build support for the system.
The Cape Fear Valley Medical Center in Fayetteville, N.C., is located in the Buckhead Creek Watershed, a 4.9-square-mile area that was plagued by flooding as development changed the landscape. Until recently, employees at the medical center’s Cumberland Hospital annex feared for their safety during major storms because heavy rains caused water to overflow onto the hospital’s parking lot, rush down the pavement and pound on the front door.
Flashboards were installed at the hospital’s front door to prevent water from getting into the building. But that was only a “bandage” solution.
To solve the flooding problem, the hospital enlisted Dayton, Ohio-based Woolpert, an engineering-GIS consulting firm, which recommended linking hydrologic and hydraulic modeling software with a GIS to identify problems and solutions. The Rose Group, a Fayetteville-based civil engineering firm hired by the Fayetteville Stormwater Management Department to solve the stormwater problems, partnered with the consulting firm to perform modeling.
The company collected storm drainage data for all of the pipes, manholes, junction boxes, inlets, channels, ditches and swales, and it surveyed the coordinates for all stormwater features in the study area. The data was entered into a digital file in ASCII format, allowing for development of enhanced GIS coverages for stormwater infrastructure and inclusion of information about soils, land uses, planimetrics and topography. Those coverages were used to develop and model parameter inputs and to serve as the basis for developing stormwater management GIS applications.
Two different types of models were used to evaluate the project area for 2- through 50-year rainfall events. First, the entire watershed was modeled and then subdivided into 100-acre sub-basins, for which runoff curve numbers and lag times were developed. The set-up for each basin involved identifying and coding channel, bridge/culvert and closed-system routes.
Second, a detailed inventory was conducted, and a 1.5-square-mile project area, which consisted of closed systems, open channels and culverts, was modeled. That helped the partners evaluate the drainage characteristics of the existing system and provided detailed hydraulic information about flooding problems. The modeling results then were compared to known flooding complaint locations.
Engineers used the model to validate the hydraulics of a new system and its impact on the existing system. They were able to evaluate various alternatives and know what would happen in a given storm-frequency event before it happened.
In particular, project managers identified a “choke point” in the existing closed-pipe system, which proved to be a partial cause of the flooding at the hospital. As a result of the model, recommendations were made to increase pipe size in portions of the existing system, increase the size of existing roadway culverts, and excavate and line existing ditches.
“We were pleased with the recommendations to make infrastructure improvements to solve the water problems in the Buckhead Creek Watershed,” Fayetteville Assistant City Manager Jimmy Teal says. “Another alternative could have been buying out a lot of properties in the area, and we were trying to avoid that drastic step.”
Fayetteville also used GIS: * to help the community deal with the excess water runoff that development creates; * to assist the community in preparing for not only major storm events, but in dealing with natural disasters, such as hurricanes; * to classify and aid in remediation of potentially polluted water; * to help stormwater utilities meet environmental mandates; and * to create scenarios to help decision-makers perform quantifiable capital improvement planning.
Moreover, because modeling/GIS is visual, it helped convince government officials and the public that certain repairs, upgrades and additions were necessary.
Project ATLANTA (ATlanta Land-use ANalysis: Temperature and Air-quality), funded by the National Aeronautics and Space Administration (NASA), is using GIS and other technologies to study the effects of urban growth on the Atlanta region’s climate and air quality. Begun in 1996, the study will provide information to assist urban officials in land-use planning and management.
As cities grow, the nature of the land cover changes, moving from vegetation ground cover to paved areas. Pavement brings with it increased traffic volumes, which, in turn, bring changes in the composition of the city’s atmosphere. Some of those changes, such as pollution, contribute to hotter urban summers and the “urban heat island,” which results from concrete’s tendency to soak up and radiate heat.
Researchers for Project ATLANTA, based at Marshall Space Flight Center in Huntsville, Ala., are creating numerical models consisting of data obtained from satellites, low-flying aircraft and meteorological observances. They input the data to produce models that relate land cover change to changes in surface energy and meteorological measurements.
In addition to gathering information via satellite and aircraft, the group uses instruments on balloons, buoys and ships to expand its database. The data obtained during the next 15 to 20 years will be stored and distributed to users by complex information systems.The “customers” for the data include urban planners, environmental managers and other decision-makers, who can use the information in their efforts to mitigate climate or air quality degradation, and in their development of plans to sustain or improve the urban environment. Specifically, the models will demonstrate how large-scale environmental change is related to land use as well as human health and well-being.
Project ATLANTA already has determined the pattern of urban growth in Atlanta from 1973 to 1992. It has generated land-use, cover and change statistics, and the thermal characteristics of the region; estimated soil moisture and vegetative cover; and instituted a model-based assessment of meteorology and air quality.
Efforts are under way to provide Atlanta’s decision-makers with the scientific results, as well as other cities. For more information, visit the Project ATLANTA home page at http://wwwghcc.msfc.nasa.gov/ atlanta.
Many types of data, from aerial photographs to detailed maps, go into building a GIS. Keeping the GIS in sync with a growing community can create a challenge for local governments, and many have adopted a global positioning system (GPS) to keep up with frequently changing data.
GPS technology offers the ability to record detailed information about virtually any object while simultaneously gathering highly accurate position data. Local authorities have successfully implemented GPS data collection systems for mapping new subdivisions, utility rights-of-way, street furniture, wildlife habitat, underground gas lines and more. The initial step in using GPS for data collection involves creating the menu system, called a feature file or data directory, which guides a user through the data-gathering process. A typical GPS includes PC software that makes creation of the menus as simple as entering the names of the features to be mapped and the attributes needed to describe them.
For example, to map signs, a user might enter the feature type “sign” followed by the attributes “type,” “condition” and “height.” For fire hydrants, the feature type “hydrant” could be entered, along with the attributes “color,” “condition” and “identification number.” Once the menu is created, it can be uploaded to the user’s hand-held computer for use in the field.
With GPS data collection, the operator actually gathers data in the field while looking at the object he is mapping. He enters point-specific attribute information while the GPS simultaneously collects position data. When the data-collection session ends, the GPS is brought back to the main office, and the information is downloaded to a PC for processing.
GPS allows for rapid data collection — a boon for field and office workers, who can acquire the most detailed information. Additionally, GPS allows users to build a quality GIS and continually maintain the system with up-to-date records.
Phoenix has developed a new educational tool to incorporate GIS technology in local schools. The AuThenTiCITY program was launched last fall to help students learn about their communities through GIS mapping software. The program introduces students to workplace-type software, improves workplace readiness and enlists help from students for community problem-solving.
Students are able to create and then study maps of their own neighborhoods, surrounding streets and the entire city. They can research geographical data and incorporate their findings into computer-based maps. The GIS also can be used to augment lessons in history, geography or political science.
Schools participating in the program receive software from ESRI, Redlands, Calif., four gigabytes of geographic data, a base map of Phoenix, background information and tutorial materials. The package also includes a school site license that allows the software to be copied in multiple classrooms. The Phoenix program was developed with a grant from AT&T, New York.
Teachers are participating in training programs provided by the Phoenix Youth and Education Office. Teachers began training sessions in September 1998, and more sessions will be held in 1999.
In north central Colorado, where the Rocky Mountains rise abruptly from the plains, the weather is as dramatic as the topography. Fort Collins, located about 60 miles north of Denver, is a frequent player in that drama.
With the Cache la Poudre River, Spring Creek, Dry Creek, Fossil Creek, Cooper Slough and Boxelder Creek in the area, Fort Collins has been threatened with sudden and severe floods since its settlement more than 125 years ago. However, last year, the city’s 102,000 residents endured one of the heaviest rainstorms in Colorado history.On July 28, rains pounded Fort Collins, and, in 30 hours, the storm had delivered 14.5 inches of water (equalling the city’s normal total rainfall per year). Furthermore, more than half that amount fell in just six hours.
“It was unbelievable,” says Glenn Levy, city emergency manager and incident commander for the ’97 flood. “We had to rescue 462 people from imminent death that night.”Despite the storm’s violence, property damage was minimized, thanks in great part to the city’s established drainage and flood management programs. For example, since 1989, Fort Collins had spent $5 million to acquire and relocate flood-prone properties, construct channels, redesign bridges and improve storm drainage in the Spring Creek area.
“Fort Collins has done a great job over the last 20 years in removing structures from the floodplain,” Levy says. “If we hadn’t relocated people over the past 20 years, the ’97 flood would have been much more destructive.” The city continues to acquire flood-prone properties, and it has preserved 958 acres of open space in the floodplain to avoid creating new flood risks.
In addition to redefining the community’s land use, Fort Collins is emphasizing hazard and safety education in its stormwater management program. “We’re actually using the fire prevention model of education,” Levy says. “We all remember ‘stop, drop and roll.’ We have got to get to kids and teach them how to behave, how to react, what to do in the event of a natural disaster.
“And we have got to go to where people are,” he adds. “That’s the only way they are going to listen. Our approach must be creative — maybe putting a safety message on the first few minutes of children’s videos. We absolutely must teach people that they are responsible for their actions and that they have to know how to behave to survive.”Looking beyond individual response, Fort Collins is using technology as a means of strengthening its flood response capabilities. Its GIS database includes digitized flood maps, and the city plans to develop real-time GIS capabilities with the help of partners including Colorado State University, Fort Collins; the U.S. Army Corps of Engineers, Washington, D.C.; FEMA; and the National Institute for Building Sciences, Washington, D.C.
“Geographical information systems are frequently used to map a wide range of data in a digital format, but generating such maps in real time hasn’t been put into practice yet,” says Marsha Hilmes, floodplain administrator for Fort Collins Utilities. “We plan to develop a database that includes current geographic information on the city’s infrastructure, such as streets, private and public critical facilities, bodies of water, irrigation ditches, and stormwater facilities, along with emergency notification information, aerial photos, digital topographic mapping, land-use data and soils information, and then tie in real-time weather data.
“Forecasts and radar data are available on a test basis through the National Weather Service’s Local Data Acquisition Dissemination,” she explains. “We will combine that with real-time data gathered from stream flow and precipitation gauges that is sent by radio telemetry to a base station. That information will be tied in to hydraulic and hydrologic computer models, and, when graphically displayed, it will show flooding as it is occurring.”
When completed (a timetable has not been set), the Real-time Flood Inundation Mapping and Notification System will assist officials in monitoring flooding of the city’s infrastructure and will prompt timely emergency response. For example, it will allow officials to calibrate the city’s hydraulic models and run “what if” scenarios to assist in planning for a flood event and in making decisions regarding land use and relocation.Additionally, the system will be able to anticipate when a specific intersection will be flooded, and it will issue an alert to block off streets before they become dangerous. Finally, the mapping system will encourage evacuation before a flood becomes life-threatening.
Fort Collins has requested more than $400,000 from FEMA to fund the mapping project, although actual costs will be much higher. Already, volunteers are playing an important role in contributing time and materials. For example, Hewlett-Packard, based in Palo Alto, Calif., has donated hardware for the project, and ESRI, based in Redlands, Calif., is developing much of the software.
Together, relocation, education and technology will reduce Mother Nature’s future toll on Fort Collins, Levy notes. “We can’t eliminate floods and other natural hazards, but we can eliminate or reduce the impact that those events have on people’s lives,” he says.