Search USGS⌕ Search
Home/Archive/USGS

USGS · sir20115236

An analytical method for predicting postwildfire peak discharges

John A. Moody
View original source ↗Export metadata ↓

Abstract

An analytical method presented here that predicts postwildfire peak discharge was developed from analysis of paired rainfall and runoff measurements collected from selected burned basins. Data were collected from 19 mountainous basins burned by eight wildfires in different hydroclimatic regimes in the western United States (California, Colorado, Nevada, New Mexico, and South Dakota). Most of the data were collected for the year of the wildfire and for 3 to 4 years after the wildfire. These data provide some estimate of the changes with time of postwildfire peak discharges, which are known to be transient but have received little documentation. The only required inputs for the analytical method are the burned area and a quantitative measure of soil burn severity (change in the normalized burn ratio), which is derived from Landsat reflectance data and is available from either the U.S. Department of Agriculture Forest Service or the U.S. Geological Survey. The method predicts the postwildfire peak discharge per unit burned area for the year of a wildfire, the first year after a wildfire, and the second year after a wildfire. It can be used at three levels of information depending on the data available to the user; each subsequent level requires either more data or more processing of the data. Level 1 requires only the burned area. Level 2 requires the burned area and the basin average value of the change in the normalized burn ratio. Level 3 requires the burned area and the calculation of the hydraulic functional connectivity, which is a variable that incorporates the sequence of soil burn severity along hillslope flow paths within the burned basin. Measurements indicate that the unit peak discharge response increases abruptly when the 30-minute maximum rainfall intensity is greater than about 5 millimeters per hour (0.2 inches per hour). This threshold may relate to a change in runoff generation from saturated-excess to infiltration-excess overland flow. The threshold value was about 7.6 millimeters per hour for the year of the wildfire and the first year after the wildfire, and it was about 11.1 millimeters per hour for the second year after the wildfire.

Explore related subjects

Scientific Investigations ReportReport

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

John A. Moody. 2012. An analytical method for predicting postwildfire peak discharges. https://doi.org/10.3133/sir20115236

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Baseline water-quality inventory and summary for the Paterson Great Falls National Historical Park, New Jersey

The Paterson Great Falls National Historical Park (PAGR), established in 2011 in the City of Paterson, New Jersey, contains many cultural, historical, and natural resources. Because of the PAGR’s young age and limited resources, a long record of natural resource data is not available for use to guide future park management and planning decisions. A detailed natural resource inventory was identified as an immediate need in the “Foundation Document—Paterson Great Falls National Historical Park,” given the history of extensive industrial activity throughout the PAGR and the Passaic River Basin. The U.S. Geological Survey, in cooperation with the National Park Service and the Urban Waters Federal Partnership for the Lower Passaic River, inventoried water-quality monitoring efforts and compiled historical water-quality data from secondary data sources to define baseline conditions in the PAGR and the surrounding study area. This report documents the methods used to harmonize water-quality data aggregated from multiple sources for the PAGR study area. Procedures implemented during data harmonization include compiling data from multiple sources, assessing the dataset for completeness, addressing metadata concerns, and creating a consistent and quality-assured dataset for future analysis. The harmonized dataset contains 14 aggregated surface-water sites, 1,103 individual sampling days, and 32,000 water-quality records throughout the period of record defined for this study (1952–2021). Summary statistics and comparison to water-quality criteria are provided for focus parameters that can support PAGR management, including field properties, suspended material, total dissolved solids, specific conductance, chloride, sulfate, Escherichia coli, nutrients, contaminants of concern related to fish consumption advisories, and litter and floatable debris. A spatial data gap was identified for the recreational area near the base of the Great Falls and immediately downstream from a known combined sewer overflow discharge location. Analytic data gaps were identified for continuous streamflow and water-quality parameters, floatable debris characterization, and harmful algal blooms identification. Continuous collection of contaminants of concern was identified as a temporal data gap, as these parameters were not consistently collected within the study area. The water-quality data synthesis and summary presented in this report can assist PAGR staff in understanding the complex baseline water resources within the study area and can serve as a baseline to design future water-quality monitoring efforts and evaluate changes in water quality over time. The harmonized dataset, as well as future New Jersey Department of Environmental Protection and New Jersey Harbor Discharge Group monitoring data and assessments, can also be used to examine the status and trends in surface-water quality, support compliance with the Clean Water Act (33 U.S.C. 1251 et seq.), and further investigate changes to park water resources that can affect ecological and human health.

New Jersey↗
USGS2026

Slip tendency and dilation tendency of Quaternary faults in the Great Basin region, Arizona, California, Idaho, Nevada, Oregon, Utah, and Wyoming

This report presents the results of slip tendency and dilation tendency analysis of Quaternary faults in the Great Basin region, in the states of Arizona, California, Idaho, Nevada, Oregon, Utah, and Wyoming. This effort was undertaken as part of two studies: the U.S. Department of Energy Geothermal Technologies Office-funded Innovative Geothermal Exploration through Novel Investigations of Undiscovered Systems (INGENIOUS) project, which is a multidisciplinary, multi-institution effort to develop new methodologies and best practices to accelerate the discovery of new, commercially viable hydrothermal resources; and the U.S. Geological Survey Geothermal Resources Investigations Project. The goal of this work is to identify faults and fault segments that are appropriately oriented to be stress-loaded for slip or to dilate under the ambient stress conditions. Both conditions may make such faults more likely to host permeability and fluid flow relative to other faults in the region. Slip tendency and dilation tendency were calculated for all fault segments in the study area from the U.S. Geological Survey Quaternary Fault and Fold Database. Results demonstrate that faults with high slip tendency and dilation tendency are common in the Great Basin region. The areas containing many high slip tendency and dilation tendency fault segments are associated with high strain rates. These areas also host a relatively high proportion of the known hydrothermal systems. This indicates that faults with high slip tendency and dilation tendency in areas with high strain-rate are potentially most prospective for hosting hydrothermal systems. The database published in coordination with this report contains the slip tendency and dilation tendency results data, including the fault geometry and stress data used to calculate these quantities, for both the Great Basin study area and the smaller INGENIOUS study area.

Arizona, California, Idaho, Nevada, Oregon, Utah, ↗
USGS2026

A spatial analysis of the groundwater emergence flood hazard in Long Island, New York, and coastal areas surrounding Long Island Sound in New York, Connecticut, and Rhode Island

Long Island, New York, and nearby coastal areas surrounding Long Island Sound are densely populated and, like other coastal areas, are susceptible to flooding from several potential sources, including stormwater from precipitation events, tidal flooding and storm surge, and groundwater emergence flooding. Groundwater emergence fooding refers to the intersection of a rising water table with land surface or critical infrastructure. Many studies of flood drivers either neglect or only briefly discuss how shallow groundwater conditions may contribute to or exacerbate flood conditions. As a part of a comprehensive study of compound flood hazards in the coastal areas of Long Island and Long Island Sound, a spatial analysis was completed by the U.S. Geological Survey, in cooperation with the Environmental Protection Agency’s Long Island Sound Partnership, formerly called the Long Island Sound Study, using available regional datasets to characterize the potential hazard for groundwater emergence flooding. The approximately 3,100 square mile study area was subdivided into 11,407 grid cells that were 900 meters by 900 meters (approximately 3,000 feet by 3,000 feet), for the purpose of integrating the spatial datasets to calculate and map the groundwater emergence flood hazard. The depth to the water table, hydrologic soil groups, and National Land Cover Database were harmonized to the common grid. A groundwater emergence flood hazard score was calculated for each grid cell for current average conditions following a set of rules accounting for the depth to the water table and the percentage of area within each cell with slow infiltrating soils. A scenario with a higher sea-level position was also calculated for the Long Island part of the study area. The calculated groundwater emergence flood hazard score was reviewed in conjunction with the National Land Cover Database to identify developed areas and associated infrastructure that may be at risk of potential groundwater emergence flooding. Study results indicate that the groundwater emergence flood hazard is highest in coastal areas and near surface water where the water table is close to ground surface. Inland areas away from surface waterbodies are not likely to be exposed to groundwater emergence flooding. For Long Island, in the scenario with higher sea-level position, a greater groundwater emergence flood hazard is calculated for some locations closer to the coast and where land is submerged. Away from the coast and surface-water drainage, the groundwater emergence flood hazard is similar between the current average sea-level condition and the higher sea-level position scenario.

Connecticut, New York, Rhode Island↗