William H. Asquith
William has about 34 years at the USGS encompassing a wide range of algorithms and statistical and extreme value frequency studies of meteorology, surface water hydrology, and other water resources topics such as data acquisition, hydraulics, hydrologic regionalization, and research mentoring on statistical methods and algorithms.
Recent (2016–2026) research includes copula methods and algorithms; exceptionally low annual exceedance probability (AEP) flood events; regulated flood-frequency approaches; N-day volumetric flood frequency bias correction for all of US and Territories; statistics of USGS discharge measurements; technical advising on probable maximum precipitation in Texas and New Mexico-Colorado; flood- and rainfall-hazards for the Qashqadaryo Region, Uzbekistan, including defining an equal-area grid for Central Asian studies; small watershed hydrometeorological station operation; missing-record estimation; real-time uncertainty forecasting for hydrometeorological stations, and groundwater level informatics and machine-learning applications for prediction of monthly water-level grids for the Mississippi River Valley alluvial aquifer underlying the Mississippi River Alluvial Plain and Chicot aquifer, southwestern Louisiana; long-term trend analyses of daily salinity predictions for 91 monitoring locations in bays and estuaries of the gulf coast with statistical methods including Cubist, Randomforest, and Support Vector Machines; Texas lake-evaporation validation by probabilistic methods (linear moments); and reduction in USGS staffing efforts in groundwater monitoring with minimization of loss of information content from the Louisiana network.
Recent cooperators include Gulf Coast Ecosystem Restoration Council, Environment Agency – Abu Dhabi (2016−18) and Ministry of Ecology, Environmental Protection and Climate Change for the Republic of Uzbekistan (2021−26) via USGS Office of International Programs, Texas Commission on Environmental Quality, Texas Department of Transportation, Texas Water Development Board, U.S. Army Corps of Engineers, U.S. Nuclear Regulatory Commission, and USGS Office of Quality Assurance.
Thrice featured four-city speaker in 2016, 2017, and 2018 in Bolivia for Universidad Catolica Boliviana and U.S. State Department, and USGS Surfacewater Mission co-lead to Uzbekistan (June 2022, April 2024, September 2024).
Education and Certifications
Institution: Texas Tech University (TTU), College of Engineering, Lubbock, 2008–2011
Degree: Ph.D. (Civil Engineering, May 2011)Institution: University of Texas at Austin, Jackson School of Geosciences, Geoscience, 1998–2003
Degree: Ph.D. (Geosciences, May 2003)Institution: University of Texas at Austin, College of Engineering, 1988–1994
Degrees: B.S. (Civil Engineering, Dec. 1992); M.S. (Civil Engineering, May 1994)
Affiliations and Memberships*
Professional Geoscientist no. 1494, State of Texas 2003–present
Science and Products
Filter Total Items: 70
Synthesis of rainfall and runoff data used for Texas Department of Transportation Research Projects 0-4193 and 0-4194 Synthesis of rainfall and runoff data used for Texas Department of Transportation Research Projects 0-4193 and 0-4194
In the early 2000s, the Texas Department of Transportation funded several research projects to examine the unit hydrograph and rainfall hyetograph techniques for hydrologic design in Texas for the estimation of design flows for stormwater drainage systems. A research consortium comprised of Lamar University, Texas Tech University, the University of Houston, and the U.S. Geological Survey...
Authors
William H. Asquith, David B. Thompson, Theodore G. Cleveland, Xing Fang
Atlas of depth-duration frequency of precipitation annual maxima for Texas Atlas of depth-duration frequency of precipitation annual maxima for Texas
Ninety-six maps depicting the spatial variation of the depth-duration frequency of precipitation annual maxima for Texas are presented. The recurrence intervals represented are 2, 5, 10, 25, 50, 100, 250, and 500 years. The storm durations represented are 15 and 30 minutes; 1, 2, 3, 6, and 12 hours; and 1, 2, 3, 5, and 7 days. The maps were derived using geographically referenced...
Authors
William H. Asquith, Meghan C. Roussel
Empirical, dimensionless, cumulative-rainfall hyetographs developed from 1959-86 storm data for selected small watersheds in Texas Empirical, dimensionless, cumulative-rainfall hyetographs developed from 1959-86 storm data for selected small watersheds in Texas
A database of incremental cumulative-rainfall values for storms that occurred in small urban and rural watersheds in north and south central Texas during the period from 1959 to 1986 was used to develop empirical, dimensionless, cumulative-rainfall hyetographs. Storm-quartile classifications were determined from the cumulative-rainfall values, which were divided into data groups on the...
Authors
Tara Williams-Sether, William H. Asquith, David B. Thompson, Theodore G. Cleveland, Xing Fang
Atlas of depth-duration frequency of precipitation annual maxima for Texas Atlas of depth-duration frequency of precipitation annual maxima for Texas
The objective of this Texas Department of Transportation (TxDOT) and U.S. Geological Survey (USGS) cooperatively funded project was to develop a simple-to-use atlas of precipitation depths in Texas for selected storm durations and frequencies on the basis of the research results and unpublished digital archives of Asquith (1998). The selected storm durations are 15 and 30 minutes; 1, 2...
Authors
William H. Asquith, Meghan C. Roussel
Atlas of interoccurrence intervals for selected thresholds of daily precipitation in Texas Atlas of interoccurrence intervals for selected thresholds of daily precipitation in Texas
A Poisson process model is used to define the distribution of interoccurrence intervals of daily precipitation in Texas. A precipitation interoccurrence interval is the time period between two successive rainfall events. Rainfall events are defined as daily precipitation equaling or exceeding a specified depth threshold. Ten precipitation thresholds are considered: 0.05, 0.10, 0.25, 0.50...
Authors
William H. Asquith, Meghan C. Roussel
Effects of regulation on L-moments of annual peak streamflow in Texas Effects of regulation on L-moments of annual peak streamflow in Texas
Several techniques exist to estimate annual peak-streamflow frequency for streamflows that have recurrence intervals ranging from 2 to 500 years for natural (unregulated) drainage basins in Texas. Unfortunately, such techniques have limited applicability in regulated basins. There are numerous regulated basins throughout Texas, which has more than 7,000 dams that are identified by Texas...
Authors
William H. Asquith
Depth-Duration Frequency of Precipitation for Oklahoma Depth-Duration Frequency of Precipitation for Oklahoma
A regional frequency analysis was conducted to estimate the depth-duration frequency of precipitation for 12 durations in Oklahoma (15, 30, and 60 minutes; 1, 2, 3, 6, 12, and 24 hours; and 1, 3, and 7 days). Seven selected frequencies, expressed as recurrence intervals, were investigated (2, 5, 10, 25, 50, 100, and 500 years). L-moment statistics were used to summarize depth-duration...
Authors
Robert L. Tortorelli, Alan Rea, William H. Asquith
Areal-reduction factors for the precipitation of the 1-day design storm in Texas Areal-reduction factors for the precipitation of the 1-day design storm in Texas
The reduction of the precipitation depth from a design storm for a point to an effective (mean) depth over a watershed often is important for cost-effective design of hydraulic structures by reducing the volume of precipitation. A design storm for a point is the depth of precipitation that has a specified duration and frequency (recurrence interval). The effective depth can be calculated...
Authors
William H. Asquith
Site-specific estimation of peak-streamflow frequency using generalized least-squares regression for natural basins in Texas Site-specific estimation of peak-streamflow frequency using generalized least-squares regression for natural basins in Texas
The U.S. Geological Survey, in cooperation with the Texas Department of Transportation, has developed a computer program to estimate peak-streamflow frequency for ungaged sites in natural basins in Texas. Peak-streamflow frequency refers to the peak streamflows for recurrence intervals of 2, 5, 10, 25, 50, and 100 years. Peak-streamflow frequency estimates are needed by planners...
Authors
William H. Asquith, R.M. Slade
Digital data sets of depth-duration frequency of precipitation for Oklahoma Digital data sets of depth-duration frequency of precipitation for Oklahoma
These geospatial data sets were produced as part of a regional precipitation frequency analysis for Oklahoma. The data sets consist of surface grids of precipitation depths for seven frequencies (expressed as recurrence intervals of 2-, 5-, 10-, 25-, 50-, 100-, and 500-years) and 12 durations (15-, 30-, and 60-minutes; 1-, 2-, 3-, 6-, 12-, and 24-hours; and 1-, 3-, and 7-days). Eighty...
Authors
Alan Rea, Robert L. Tortorelli
Depth-duration frequency of precipitation for Texas Depth-duration frequency of precipitation for Texas
The U.S. Geological Survey, in cooperation with the Texas Department of Transportation, conducted a study of the depth-duration frequency of precipitation for Texas. Depth-duration frequency is an estimate of the depth of precipitation for a specified duration and frequency or recurrence interval. For this report, precipitation durations of 15, 30, and 60 minutes; 1, 2, 3, 6, 12, and 24...
Authors
William H. Asquith
Extreme precipitation depths for Texas, excluding the Trans-Pecos region Extreme precipitation depths for Texas, excluding the Trans-Pecos region
The U.S. Geological Survey, in cooperation with the Texas Department of Transportation, conducted a study of extreme precipitation depths for various durations and storm areas for Texas, excluding the Trans-Pecos region. The extreme precipitation depth is an estimate, from documented storms, of the largest precipitation depth expected to occur over a given area. The extreme precipitation...
Authors
Jennifer Lanning-Rush, William H. Asquith, Raymond M. Slade
Filter Total Items: 48
No Result Found
Filter Total Items: 22
Science and Products
Filter Total Items: 70
Synthesis of rainfall and runoff data used for Texas Department of Transportation Research Projects 0-4193 and 0-4194 Synthesis of rainfall and runoff data used for Texas Department of Transportation Research Projects 0-4193 and 0-4194
In the early 2000s, the Texas Department of Transportation funded several research projects to examine the unit hydrograph and rainfall hyetograph techniques for hydrologic design in Texas for the estimation of design flows for stormwater drainage systems. A research consortium comprised of Lamar University, Texas Tech University, the University of Houston, and the U.S. Geological Survey...
Authors
William H. Asquith, David B. Thompson, Theodore G. Cleveland, Xing Fang
Atlas of depth-duration frequency of precipitation annual maxima for Texas Atlas of depth-duration frequency of precipitation annual maxima for Texas
Ninety-six maps depicting the spatial variation of the depth-duration frequency of precipitation annual maxima for Texas are presented. The recurrence intervals represented are 2, 5, 10, 25, 50, 100, 250, and 500 years. The storm durations represented are 15 and 30 minutes; 1, 2, 3, 6, and 12 hours; and 1, 2, 3, 5, and 7 days. The maps were derived using geographically referenced...
Authors
William H. Asquith, Meghan C. Roussel
Empirical, dimensionless, cumulative-rainfall hyetographs developed from 1959-86 storm data for selected small watersheds in Texas Empirical, dimensionless, cumulative-rainfall hyetographs developed from 1959-86 storm data for selected small watersheds in Texas
A database of incremental cumulative-rainfall values for storms that occurred in small urban and rural watersheds in north and south central Texas during the period from 1959 to 1986 was used to develop empirical, dimensionless, cumulative-rainfall hyetographs. Storm-quartile classifications were determined from the cumulative-rainfall values, which were divided into data groups on the...
Authors
Tara Williams-Sether, William H. Asquith, David B. Thompson, Theodore G. Cleveland, Xing Fang
Atlas of depth-duration frequency of precipitation annual maxima for Texas Atlas of depth-duration frequency of precipitation annual maxima for Texas
The objective of this Texas Department of Transportation (TxDOT) and U.S. Geological Survey (USGS) cooperatively funded project was to develop a simple-to-use atlas of precipitation depths in Texas for selected storm durations and frequencies on the basis of the research results and unpublished digital archives of Asquith (1998). The selected storm durations are 15 and 30 minutes; 1, 2...
Authors
William H. Asquith, Meghan C. Roussel
Atlas of interoccurrence intervals for selected thresholds of daily precipitation in Texas Atlas of interoccurrence intervals for selected thresholds of daily precipitation in Texas
A Poisson process model is used to define the distribution of interoccurrence intervals of daily precipitation in Texas. A precipitation interoccurrence interval is the time period between two successive rainfall events. Rainfall events are defined as daily precipitation equaling or exceeding a specified depth threshold. Ten precipitation thresholds are considered: 0.05, 0.10, 0.25, 0.50...
Authors
William H. Asquith, Meghan C. Roussel
Effects of regulation on L-moments of annual peak streamflow in Texas Effects of regulation on L-moments of annual peak streamflow in Texas
Several techniques exist to estimate annual peak-streamflow frequency for streamflows that have recurrence intervals ranging from 2 to 500 years for natural (unregulated) drainage basins in Texas. Unfortunately, such techniques have limited applicability in regulated basins. There are numerous regulated basins throughout Texas, which has more than 7,000 dams that are identified by Texas...
Authors
William H. Asquith
Depth-Duration Frequency of Precipitation for Oklahoma Depth-Duration Frequency of Precipitation for Oklahoma
A regional frequency analysis was conducted to estimate the depth-duration frequency of precipitation for 12 durations in Oklahoma (15, 30, and 60 minutes; 1, 2, 3, 6, 12, and 24 hours; and 1, 3, and 7 days). Seven selected frequencies, expressed as recurrence intervals, were investigated (2, 5, 10, 25, 50, 100, and 500 years). L-moment statistics were used to summarize depth-duration...
Authors
Robert L. Tortorelli, Alan Rea, William H. Asquith
Areal-reduction factors for the precipitation of the 1-day design storm in Texas Areal-reduction factors for the precipitation of the 1-day design storm in Texas
The reduction of the precipitation depth from a design storm for a point to an effective (mean) depth over a watershed often is important for cost-effective design of hydraulic structures by reducing the volume of precipitation. A design storm for a point is the depth of precipitation that has a specified duration and frequency (recurrence interval). The effective depth can be calculated...
Authors
William H. Asquith
Site-specific estimation of peak-streamflow frequency using generalized least-squares regression for natural basins in Texas Site-specific estimation of peak-streamflow frequency using generalized least-squares regression for natural basins in Texas
The U.S. Geological Survey, in cooperation with the Texas Department of Transportation, has developed a computer program to estimate peak-streamflow frequency for ungaged sites in natural basins in Texas. Peak-streamflow frequency refers to the peak streamflows for recurrence intervals of 2, 5, 10, 25, 50, and 100 years. Peak-streamflow frequency estimates are needed by planners...
Authors
William H. Asquith, R.M. Slade
Digital data sets of depth-duration frequency of precipitation for Oklahoma Digital data sets of depth-duration frequency of precipitation for Oklahoma
These geospatial data sets were produced as part of a regional precipitation frequency analysis for Oklahoma. The data sets consist of surface grids of precipitation depths for seven frequencies (expressed as recurrence intervals of 2-, 5-, 10-, 25-, 50-, 100-, and 500-years) and 12 durations (15-, 30-, and 60-minutes; 1-, 2-, 3-, 6-, 12-, and 24-hours; and 1-, 3-, and 7-days). Eighty...
Authors
Alan Rea, Robert L. Tortorelli
Depth-duration frequency of precipitation for Texas Depth-duration frequency of precipitation for Texas
The U.S. Geological Survey, in cooperation with the Texas Department of Transportation, conducted a study of the depth-duration frequency of precipitation for Texas. Depth-duration frequency is an estimate of the depth of precipitation for a specified duration and frequency or recurrence interval. For this report, precipitation durations of 15, 30, and 60 minutes; 1, 2, 3, 6, 12, and 24...
Authors
William H. Asquith
Extreme precipitation depths for Texas, excluding the Trans-Pecos region Extreme precipitation depths for Texas, excluding the Trans-Pecos region
The U.S. Geological Survey, in cooperation with the Texas Department of Transportation, conducted a study of extreme precipitation depths for various durations and storm areas for Texas, excluding the Trans-Pecos region. The extreme precipitation depth is an estimate, from documented storms, of the largest precipitation depth expected to occur over a given area. The extreme precipitation...
Authors
Jennifer Lanning-Rush, William H. Asquith, Raymond M. Slade
Filter Total Items: 48
No Result Found
Filter Total Items: 22
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government