New GIS Tool Helps Foresters Curb Damage from Wildfires and Target Conservation Cost-Effectively

A robust, new geographic information systems (GIS) software tool developed by a University at Buffalo geographer is helping the U.S. Forest Service to more quickly and accurately assess and contain the devastation wrought by forest fires, such as last summer’s Hayman Fire, Colorado’s worst wildfire ever. That fire, which covered more than 137,000 acres and blazed for more than two weeks, destroyed 133 homes and caused damage of approximately $39 million.

The new tool, to be presented in New Orleans on Thursday (March 6, 2003) at the annual meeting of the Association of American Geographers, modifies a computer model developed originally by the U.S. Agricultural Research Service that is used to assess soil erosion in agricultural areas.

“Last year’s devastating forest-fire season has prompted forest, wildlife and watershed managers to call for better ways of rapidly assessing how fires have impacted soil erosion and sediment delivery in streams,” said Chris Renschler, Ph.D., assistant professor of geography in the UB College of Arts and Sciences.

“Right after a fire, landslides, avalanches and mud flows are not uncommon,” he explained, “because the upper layer of the soil may become water-repellant and is most vulnerable to being washed away by increased runoff from rainfall or snow melt.”

This surface runoff, he added, can be anywhere from 10 to 100 times greater than in an undisturbed forest, potentially threatening camp and recreation sites, residential areas and drinking-water sources.

“Ideally, in order to reduce this risk, watershed managers need to quickly plan and implement soil and water conservation measures,” Renschler said. “But determining which areas are most vulnerable to damage has been a tedious and labor-intensive process.”

Typically, Burned Area Emergency Rehabilitation teams are dispatched into the field to determine the distribution of severely burned areas and to evaluate watersheds at risk. These Forest Service personnel then return to their offices to combine these field observations with satellite and aerial imagery, soil maps, topographic data and climate information to estimate the erosion potential.

Renschler’s tool, called GeoWEPP (Geo-spatial interface for the Water Erosion Prediction Project), potentially can condense this entire process into a couple of steps, all done at the computer, with a minimum of additional fieldwork.

It does so by taking advantage of GIS data, topographic data, soil and land cover, and remote sensing data gathered by satellite available on the Internet from federal-government Web sites.

“GeoWEPP estimates the runoff and erosion processes that have occurred or may occur in the years following the fire as a result of the fire and any mitigation measures,” explained Renschler.

“It allows forest personnel to complete quickly the initial assessments on the computer, identifying the areas that are most likely to be vulnerable to erosion,” said William Elliot, Ph.D., project leader for soil and water engineering with the U.S. Forest Service at the Rocky Mountain Research Station in Moscow, Idaho, which is funding Renschler’s work. Elliot is collaborating with Renschler to customize and test GeoWEPP.

Once these determinations have been made, GeoWEPP can “guide” the user to select the best and most cost-effective conservation measures to implement, said Renschler.

“In this way, GeoWEPP significantly shortens the time period for analysis before the BAER teams can start implementing conservation measures on the most sensitive areas,” he said.

In addition, he said, it allows managers to target expensive treatments only on areas most susceptible to erosion. The cost of such mitigation measures on Forest Service lands following the Hayman Fire, for example, exceeds $14 million to date.

“With GeoWEPP, we have created a user-friendly interface for natural-resource managers to take full advantage of GIS capabilities and data now available on the Web,” said Renschler. “The challenge was to make complicated computer models and analysis tools more usable both by managers and even members of the public.”

GeoWEPP can be downloaded from Renschler’s Web site at http://www.geog.buffalo.edu/~rensch/geowepp.

Renschler’s previous work on GeoWEPP for agricultural sites was funded by the U.S. Department of Agriculture, National Soil Erosion Laboratory and Purdue University.