|
<br />Introduction
<br />
<br />"Wildfire is a natural occurrence in this tinder-dry climate. But when humans put themselves in harms's
<br />
<br />
<br />way, a natural phenomenon can be transformed into a natural disaster." Denver Post, Firefight Starts at
<br />
<br />
<br />Home, p. 4G, July 20, 1997. CommunITies are encroaching into forested-mountain areas in many parts of
<br />
<br />
<br />the United States, particularly at the urban interface near metropolitan areas in the western UnITed States.
<br />
<br />
<br />This growth has significantly increased the risk of natural hazards to people living in or visiting forested
<br />
<br />
<br />areas. Floods and debris flows, particularly in recently burned watersheds, pose a serious threat to human
<br />
<br />
<br />life, property, and the environment. California suffers an average annual billion dollars in costs and loses
<br />
<br />
<br />to wildfires (Weise and Martin, 1995). Increased risks remain for several years or decades until bumed
<br />
<br />
<br />areas sufficiently recover to pre-burn conditions (Evenstad and Rasely, 1995). Recent wildfires and
<br />
<br />
<br />associated flood and debris-flow hazards in southern California (Florsheim et aI., 1991; Weise and Martin,
<br />
<br />
<br />1995), Helena, Montana (Parrett, 1987), Yellowstone National Park (Meyer et aI., 1995; Ewing, 1996),
<br />
<br />
<br />Storm King Mountain, Colorado (Cannon et aI., 1995), the Wasatch Mountains in Utah (Evenstad and
<br />
<br />
<br />Rasely, 1995), Boise, Idaho, and Bandelier National Monument, New Mexico, and Mesa Verde National
<br />
<br />
<br />Park, Colorado (all in 1996) emphasize the potential risk for loss of life, property damage, and costs
<br />
<br />
<br />associated with hazard mITigation and watershed rehabilITation. The effects of flood runoff, sediment
<br />
<br />
<br />delivery, geomorphic changes, watershed recovery time, and the linkages among them are poorly
<br />
<br />
<br />understood for burned watersheds. Watershed, sediment, and ecosystem models may not be applicable
<br />
<br />
<br />WIThout modifications for assessing changes due to burned areas (Weise and Martin, 1995). The focus of
<br />
<br />
<br />this study was to develop a flexible, cost-efficient, monitoring and analysis approach that can be quickly
<br />
<br />
<br />implemented following wildfires wherever they may occur.
<br />
<br />Research was undertaken to monitor and determine the risk of hazards and to help mITigate, to the extent
<br />
<br />
<br />possible, loss of life and property damage from water and sediment runoff related to wildfire areas.
<br />
<br />
<br />Extensive coordination was made WITh the various government agencies involved WITh hazard mitigation,
<br />
<br />
<br />particularly the National Weather Service (NWS). An integral part of our research focuses on helping to
<br />
<br />
<br />determine threshold-rainfall conditions, which will change WITh time, that could cause hazardous flooding
<br />
<br />3
<br />
|