William H. Asquith
William has more than 28 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, and hydrologic regionalization.
Present (2016–2021) research includes exceptionally low annual exceedance probability (AEP) flood events, regulated flood-frequency, documentable climate-cycle impacts on flood-risk assessment, statistics of USGS discharge measurements, recent technical advisor on probable maximum precipitation in Texas, small watershed hydrometeorological stations, missing record estimation, real-time uncertainty forecasting for hydrometeorological stations, and groundwater level informatics and machine learning applications.
Recent cooperators include Gulf Coast Ecosystem Restoration Council, Environment Agency – Abu Dhabi via USGS Office of International Programs, Texas Commission on Environmental Quality, Texas Department of Transportation, 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.
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: 20
Quality Assurance of Water Level Records from Wells in the Mississippi River Valley Alluvial Aquifer in Missouri from the Missouri Department of Natural Resource's Well Information Management System (WIMS)
The Missouri Department of Natural Resources' (MoDNR) Well Information Management System (WIMS) is a repository for recent (1983-present) well information that includes date of completion, well construction, geology, and water level. Well information is provided by the well drillers during the permitting process and is updated regularly by MoDNR. This data set consists of well records that were dr
Datasets used to map the potentiometric surface, Mississippi River Valley alluvial aquifer, spring 2018
A potentiometric-surface map for spring 2018 was created for the Mississippi River Valley alluvial (MRVA) aquifer, which was referenced to the North American Vertical Datum of 1988 (NAVD 88), using most of the available groundwater-altitude data from wells and surface-water-altitude data from streamgages. Most of the wells were measured annually or one time, after installation, but some wells were
Observed and modeled daily streamflow values for 74 U.S. Geological Survey streamgage locations in the Trinity and Mobile-Tombigbee River basins in the Southeast United States: 2000--2009
The data and R scripts contained in this data release are provided as support for a manuscript titled, "Copula theory as a generalized framework for flow-duration curve based streamflow estimates in ungaged and partially gaged catchments" (Worland and others, 2019) submitted to Water Resources Research. The dv_input.csv contains the measured daily streamflow values for 37 streamgages in the Mobile
Summary of basin characteristics for National Hydrography Dataset, version 2 catchments in the southeastern United States, 1950 - 2010
This dataset provides numerical and categorical descriptions of 46 basin characteristics for 957 basins with observed streamflow information and 9,314 ungaged basins coinciding with 12-digit hydrologic unit code pour points that drain to the Gulf of Mexico. Characteristics are indexed by National Hydrography Dataset (NHD) version 2 COMID and USGS site number (streamflow-gaging station), where app
Heuristically-determined geospatial boundary of streams and rivers draining to the Gulf of Mexico in the south-central and southeastern United States, July 2018
Human alteration of waterways has impacted the minimum and maximum streamflow in more than 86% of monitored streams nationally and may be the primary cause for ecological impairment in river and stream ecosystems. Restoration of freshwater inflows can positively affect shellfish, fisheries, habitat, and water quality in streams, rivers, and estuaries. Increasingly, state and local decision-makers
Solar radiation for National Hydrography Dataset, version 2 catchments in the Southeastern United States: 1950 - 2010
This study is based on contiguous direct normal irradiance information from the National Renewable Energy Laboratory. Specifically, these data represent both 12-month specific average and annual average daily total solar resource averaged over surface cells of 0.1 degrees in both latitude and longitude. Spacing is about 10 kilometers in size. Direct normal irradiance is the amount of solar radiati
Estimated and measured streamflow and groundwater-level data in the Mississippi Delta
This data release provides the data that support the findings in "Characterizing groundwater and surface-water interaction using hydrograph-separation techniques and groundwater-level data throughout the Mississippi Delta" by Killian and others (2019). There are two child items below: (1) Estimated baseflow includes the baseflow_est data and metadata that contain daily mean streamflow data provid
Summary of streamflow statistics for USGS streamgages in the southeastern United States: 1950 - 2010
This dataset contains statistical descriptions of observed daily-mean streamflow for 956 sites in the southeast United States. For each site, statistical descriptions are provided according to decade for up to six decades, beginning in 1950 (1950-59 calendar years) and ending with 2000 (2000 - 2009 calendar years) with no more than 7 missing values per year in total (continuous or noncontinuous).
Filter Total Items: 67
Long-term trends in reservoir water quality and quantity in two major river basins of the southern Great Plains
Trends in water quality and quantity were assessed for 11 major reservoirs of the Brazos and Colorado river basins in the southern Great Plains (maximum period of record, 1965–2010). Water quality, major contributing-stream inflow, storage, local precipitation, and basin-wide total water withdrawals were analyzed. Inflow and storage decreased and total phosphorus increased in most reservoirs. The
Authors
D. Dawson, Matthew M. VanLandeghem, William H. Asquith, Reynaldo Patiño
Lithologic and hydrologic controls of mixed alluvial-bedrock channels in flood-prone fluvial systems: bankfull and macrochannels in the Llano River watershed, central Texas, USA
The rural and unregulated Llano River watershed located in central Texas, USA, has a highly variable flow regime and a wide range of instantaneous peak flows. Abrupt transitions in surface lithology exist along the main-stem channel course. Both of these characteristics afford an opportunity to examine hydrologic, lithologic, and sedimentary controls on downstream changes in channel morphology. Fi
Authors
Frank T. Heitmuller, Paul F. Hudson, William H. Asquith
Trend analysis and selected summary statistics of annual mean streamflow for 38 selected long-term U.S. Geological Survey streamgages in Texas, water years 1916-2012
In 2013, the U.S. Geological Survey (USGS) operated more than 500 continuous streamgages (streamflow-gaging stations) in Texas. In cooperation with the Texas Water Development Board, the USGS evaluated mean annual streamflow data for 38 selected streamgages that were active as of water year 2012. The 38 streamgages have annual mean streamflow data considered natural and unregulated. Collected annu
Authors
William H. Asquith, Dana L. Barbie
Linkage of the Soil and Water Assessment Tool and the Texas Water Availability Model to simulate the effects of brush management on monthly storage of Canyon Lake, south-central Texas, 1995-2010
The U.S. Geological Survey (USGS), in cooperation with the Texas State Soil and Water Conservation Board, developed and applied an approach to create a linkage between the published upper Guadalupe River Soil Water Assessment Tool (SWAT) brush-management (ashe juniper [Juniperus ashei]) model and the full authorization version Guadalupe River Water Availability Model (WAM). The SWAT model was publ
Authors
William H. Asquith, Johnathan R. Bumgarner
Parameter estimation for the 4-parameter Asymmetric Exponential Power distribution by the method of L-moments using R
The implementation characteristics of two method of L-moments (MLM) algorithms for parameter estimation of the 4-parameter Asymmetric Exponential Power (AEP4) distribution are studied using the R environment for statistical computing. The objective is to validate the algorithms for general application of the AEP4 using R. An algorithm was introduced in the original study of the L-moments for the A
Authors
William H. Asquith
Regression models of discharge and mean velocity associated with near-median streamflow conditions in Texas: utility of the U.S. Geological Survey discharge measurement database
A database containing more than 16,300 discharge values and ancillary hydraulic attributes was assembled from summaries of discharge measurement records for 391 USGS streamflow-gauging stations (streamgauges) in Texas. Each discharge is between the 40th- and 60th-percentile daily mean streamflow as determined by period-of-record, streamgauge-specific, flow-duration curves. Each discharge therefore
Authors
William H. Asquith
Return period adjustment for runoff coefficients based on analysis in undeveloped Texas watersheds
The rational method for peak discharge (Qp) estimation was introduced in the 1880s. The runoff coefficient (C) is a key parameter for the rational method that has an implicit meaning of rate proportionality, and the C has been declared a function of the annual return period by various researchers. Rate-based runoff coefficients as a function of the return period, C(T), were determined for 36 undev
Authors
Nirajan Dhakal, Xing Fang, William H. Asquith, Theodore G. Cleveland, David B. Thompson
Empirical flow parameters : a tool for hydraulic model validity
The objectives of this project were (1) To determine and present from existing data in Texas, relations between observed stream flow, topographic slope, mean section velocity, and other hydraulic factors, to produce charts such as Figure 1 and to produce empirical distributions of the various flow parameters to provide a methodology to "check if model results are way off!"; (2) To produce a statis
Authors
William H. Asquith, Thomas E. Burley, Theodore G. Cleveland
Generalized additive regression models of discharge and mean velocity associated with direct-runoff conditions in Texas: Utility of the U.S. Geological Survey discharge measurement database
A database containing more than 17,700 discharge values and ancillary hydraulic properties was assembled from summaries of discharge measurement records for 424 U.S. Geological Survey streamflow-gauging stations (stream gauges) in Texas. Each discharge exceeds the 90th-percentile daily mean streamflow as determined by period-of-record, stream-gauge-specific, flow-duration curves. Each discharge th
Authors
William H. Asquith, George R. Herrmann, Theodore G. Cleveland
Regression model development and computational procedures to support estimation of real-time concentrations and loads of selected constituents in two tributaries to Lake Houston near Houston, Texas, 2005-9
In December 2005, the U.S. Geological Survey (USGS), in cooperation with the City of Houston, Texas, began collecting discrete water-quality samples for nutrients, total organic carbon, bacteria (Escherichia coli and total coliform), atrazine, and suspended sediment at two USGS streamflow-gaging stations that represent watersheds contributing to Lake Houston (08068500 Spring Creek near Spring, Tex
Authors
Michael T. Lee, William H. Asquith, Timothy D. Oden
Historical streamflows of Double Mountain Fork of Brazos River and water-surface elevations of Lake Alan Henry, Garza County, Texas, water years 1962-2010
The U.S. Geological Survey (USGS), in cooperation with the City of Lubbock, Texas, operates two surface-water stations in Garza County, Tex.: USGS streamflow-gaging station 08079600 Double Mountain Fork Brazos River at Justiceburg, Tex., and 08079700 Lake Alan Henry Reservoir, a water-supply reservoir about 60 miles southeast of Lubbock, Tex., and about 10 miles east of Justiceburg, Tex. The strea
Authors
William H. Asquith, Joseph Vrabel
Annual peak streamflow and ancillary data for small watersheds in central and western Texas
Estimates of annual peak-streamflow frequency are needed for flood-plain management, assessment of flood risk, and design of structures, such as roads, bridges, culverts, dams, and levees. Regional regression equations have been developed and are used extensively to estimate annual peak-streamflow frequency for ungaged sites in natural (unregulated and rural or nonurbanized) watersheds in Texas (A
Authors
Glenn R. Harwell, William H. Asquith
Filter Total Items: 16
utc2nwislocal, UTC date-times to NWIS local time zones using UTC offsets
The utc2nwislocal package in the R language provides a light-weight, dependency-free utility for converting Coordinated Universal Time (UTC) base::as.POSIXct() date-time values into character-string representations for time zones. The UTC offsets for individual time zones are determined from the time-zone codes recognized by the U.S. Geological Survey National Water Information System (NWIS) datab
infoGW2visGWDB, Conversion of an infoGW object to a GWmaster object compatible with the visGWDB software
An R groundwater-data processing utility for manipulating, veracity checking, and converting an 'infoGW' object to the 'GWmaster' object for the visGWDB software with demonstration for the Mississippi River Valley alluvial aquifer
MGBT, Multiple Grubbs-Beck low-outlier test
The multiple Grubbs-Beck low-outlier test on positively distributed data is supported along, and utilities provided for noninterpretive U.S. Geological Survey (USGS) annual peak-streamflow data processing.
Source code in R to quality assure, plot, summarize, interpolate, and extend groundwater-level information, visGWDB---Groundwater-level informatics with demonstration for the Mississippi River Valley alluvial aquifer
This page contains extensive source code in the R language supporting groundwater level informatics, and the entry point is the script visGWDB.R. The approximately 4,000 lines of aggregate code requires also extensive external dependencies. The code provides for near arbitrary-scale information processing of observations or recordings of water levels associated groundwater resources. The processin
Science and Products
- Science
- Data
Filter Total Items: 20
Quality Assurance of Water Level Records from Wells in the Mississippi River Valley Alluvial Aquifer in Missouri from the Missouri Department of Natural Resource's Well Information Management System (WIMS)
The Missouri Department of Natural Resources' (MoDNR) Well Information Management System (WIMS) is a repository for recent (1983-present) well information that includes date of completion, well construction, geology, and water level. Well information is provided by the well drillers during the permitting process and is updated regularly by MoDNR. This data set consists of well records that were drDatasets used to map the potentiometric surface, Mississippi River Valley alluvial aquifer, spring 2018
A potentiometric-surface map for spring 2018 was created for the Mississippi River Valley alluvial (MRVA) aquifer, which was referenced to the North American Vertical Datum of 1988 (NAVD 88), using most of the available groundwater-altitude data from wells and surface-water-altitude data from streamgages. Most of the wells were measured annually or one time, after installation, but some wells wereObserved and modeled daily streamflow values for 74 U.S. Geological Survey streamgage locations in the Trinity and Mobile-Tombigbee River basins in the Southeast United States: 2000--2009
The data and R scripts contained in this data release are provided as support for a manuscript titled, "Copula theory as a generalized framework for flow-duration curve based streamflow estimates in ungaged and partially gaged catchments" (Worland and others, 2019) submitted to Water Resources Research. The dv_input.csv contains the measured daily streamflow values for 37 streamgages in the MobileSummary of basin characteristics for National Hydrography Dataset, version 2 catchments in the southeastern United States, 1950 - 2010
This dataset provides numerical and categorical descriptions of 46 basin characteristics for 957 basins with observed streamflow information and 9,314 ungaged basins coinciding with 12-digit hydrologic unit code pour points that drain to the Gulf of Mexico. Characteristics are indexed by National Hydrography Dataset (NHD) version 2 COMID and USGS site number (streamflow-gaging station), where appHeuristically-determined geospatial boundary of streams and rivers draining to the Gulf of Mexico in the south-central and southeastern United States, July 2018
Human alteration of waterways has impacted the minimum and maximum streamflow in more than 86% of monitored streams nationally and may be the primary cause for ecological impairment in river and stream ecosystems. Restoration of freshwater inflows can positively affect shellfish, fisheries, habitat, and water quality in streams, rivers, and estuaries. Increasingly, state and local decision-makersSolar radiation for National Hydrography Dataset, version 2 catchments in the Southeastern United States: 1950 - 2010
This study is based on contiguous direct normal irradiance information from the National Renewable Energy Laboratory. Specifically, these data represent both 12-month specific average and annual average daily total solar resource averaged over surface cells of 0.1 degrees in both latitude and longitude. Spacing is about 10 kilometers in size. Direct normal irradiance is the amount of solar radiatiEstimated and measured streamflow and groundwater-level data in the Mississippi Delta
This data release provides the data that support the findings in "Characterizing groundwater and surface-water interaction using hydrograph-separation techniques and groundwater-level data throughout the Mississippi Delta" by Killian and others (2019). There are two child items below: (1) Estimated baseflow includes the baseflow_est data and metadata that contain daily mean streamflow data providSummary of streamflow statistics for USGS streamgages in the southeastern United States: 1950 - 2010
This dataset contains statistical descriptions of observed daily-mean streamflow for 956 sites in the southeast United States. For each site, statistical descriptions are provided according to decade for up to six decades, beginning in 1950 (1950-59 calendar years) and ending with 2000 (2000 - 2009 calendar years) with no more than 7 missing values per year in total (continuous or noncontinuous). - Maps
- Publications
Filter Total Items: 67
Long-term trends in reservoir water quality and quantity in two major river basins of the southern Great Plains
Trends in water quality and quantity were assessed for 11 major reservoirs of the Brazos and Colorado river basins in the southern Great Plains (maximum period of record, 1965–2010). Water quality, major contributing-stream inflow, storage, local precipitation, and basin-wide total water withdrawals were analyzed. Inflow and storage decreased and total phosphorus increased in most reservoirs. TheAuthorsD. Dawson, Matthew M. VanLandeghem, William H. Asquith, Reynaldo PatiñoLithologic and hydrologic controls of mixed alluvial-bedrock channels in flood-prone fluvial systems: bankfull and macrochannels in the Llano River watershed, central Texas, USA
The rural and unregulated Llano River watershed located in central Texas, USA, has a highly variable flow regime and a wide range of instantaneous peak flows. Abrupt transitions in surface lithology exist along the main-stem channel course. Both of these characteristics afford an opportunity to examine hydrologic, lithologic, and sedimentary controls on downstream changes in channel morphology. FiAuthorsFrank T. Heitmuller, Paul F. Hudson, William H. AsquithTrend analysis and selected summary statistics of annual mean streamflow for 38 selected long-term U.S. Geological Survey streamgages in Texas, water years 1916-2012
In 2013, the U.S. Geological Survey (USGS) operated more than 500 continuous streamgages (streamflow-gaging stations) in Texas. In cooperation with the Texas Water Development Board, the USGS evaluated mean annual streamflow data for 38 selected streamgages that were active as of water year 2012. The 38 streamgages have annual mean streamflow data considered natural and unregulated. Collected annuAuthorsWilliam H. Asquith, Dana L. BarbieLinkage of the Soil and Water Assessment Tool and the Texas Water Availability Model to simulate the effects of brush management on monthly storage of Canyon Lake, south-central Texas, 1995-2010
The U.S. Geological Survey (USGS), in cooperation with the Texas State Soil and Water Conservation Board, developed and applied an approach to create a linkage between the published upper Guadalupe River Soil Water Assessment Tool (SWAT) brush-management (ashe juniper [Juniperus ashei]) model and the full authorization version Guadalupe River Water Availability Model (WAM). The SWAT model was publAuthorsWilliam H. Asquith, Johnathan R. BumgarnerParameter estimation for the 4-parameter Asymmetric Exponential Power distribution by the method of L-moments using R
The implementation characteristics of two method of L-moments (MLM) algorithms for parameter estimation of the 4-parameter Asymmetric Exponential Power (AEP4) distribution are studied using the R environment for statistical computing. The objective is to validate the algorithms for general application of the AEP4 using R. An algorithm was introduced in the original study of the L-moments for the AAuthorsWilliam H. AsquithRegression models of discharge and mean velocity associated with near-median streamflow conditions in Texas: utility of the U.S. Geological Survey discharge measurement database
A database containing more than 16,300 discharge values and ancillary hydraulic attributes was assembled from summaries of discharge measurement records for 391 USGS streamflow-gauging stations (streamgauges) in Texas. Each discharge is between the 40th- and 60th-percentile daily mean streamflow as determined by period-of-record, streamgauge-specific, flow-duration curves. Each discharge thereforeAuthorsWilliam H. AsquithReturn period adjustment for runoff coefficients based on analysis in undeveloped Texas watersheds
The rational method for peak discharge (Qp) estimation was introduced in the 1880s. The runoff coefficient (C) is a key parameter for the rational method that has an implicit meaning of rate proportionality, and the C has been declared a function of the annual return period by various researchers. Rate-based runoff coefficients as a function of the return period, C(T), were determined for 36 undevAuthorsNirajan Dhakal, Xing Fang, William H. Asquith, Theodore G. Cleveland, David B. ThompsonEmpirical flow parameters : a tool for hydraulic model validity
The objectives of this project were (1) To determine and present from existing data in Texas, relations between observed stream flow, topographic slope, mean section velocity, and other hydraulic factors, to produce charts such as Figure 1 and to produce empirical distributions of the various flow parameters to provide a methodology to "check if model results are way off!"; (2) To produce a statisAuthorsWilliam H. Asquith, Thomas E. Burley, Theodore G. ClevelandGeneralized additive regression models of discharge and mean velocity associated with direct-runoff conditions in Texas: Utility of the U.S. Geological Survey discharge measurement database
A database containing more than 17,700 discharge values and ancillary hydraulic properties was assembled from summaries of discharge measurement records for 424 U.S. Geological Survey streamflow-gauging stations (stream gauges) in Texas. Each discharge exceeds the 90th-percentile daily mean streamflow as determined by period-of-record, stream-gauge-specific, flow-duration curves. Each discharge thAuthorsWilliam H. Asquith, George R. Herrmann, Theodore G. ClevelandRegression model development and computational procedures to support estimation of real-time concentrations and loads of selected constituents in two tributaries to Lake Houston near Houston, Texas, 2005-9
In December 2005, the U.S. Geological Survey (USGS), in cooperation with the City of Houston, Texas, began collecting discrete water-quality samples for nutrients, total organic carbon, bacteria (Escherichia coli and total coliform), atrazine, and suspended sediment at two USGS streamflow-gaging stations that represent watersheds contributing to Lake Houston (08068500 Spring Creek near Spring, TexAuthorsMichael T. Lee, William H. Asquith, Timothy D. OdenHistorical streamflows of Double Mountain Fork of Brazos River and water-surface elevations of Lake Alan Henry, Garza County, Texas, water years 1962-2010
The U.S. Geological Survey (USGS), in cooperation with the City of Lubbock, Texas, operates two surface-water stations in Garza County, Tex.: USGS streamflow-gaging station 08079600 Double Mountain Fork Brazos River at Justiceburg, Tex., and 08079700 Lake Alan Henry Reservoir, a water-supply reservoir about 60 miles southeast of Lubbock, Tex., and about 10 miles east of Justiceburg, Tex. The streaAuthorsWilliam H. Asquith, Joseph VrabelAnnual peak streamflow and ancillary data for small watersheds in central and western Texas
Estimates of annual peak-streamflow frequency are needed for flood-plain management, assessment of flood risk, and design of structures, such as roads, bridges, culverts, dams, and levees. Regional regression equations have been developed and are used extensively to estimate annual peak-streamflow frequency for ungaged sites in natural (unregulated and rural or nonurbanized) watersheds in Texas (AAuthorsGlenn R. Harwell, William H. Asquith - Software
Filter Total Items: 16
utc2nwislocal, UTC date-times to NWIS local time zones using UTC offsets
The utc2nwislocal package in the R language provides a light-weight, dependency-free utility for converting Coordinated Universal Time (UTC) base::as.POSIXct() date-time values into character-string representations for time zones. The UTC offsets for individual time zones are determined from the time-zone codes recognized by the U.S. Geological Survey National Water Information System (NWIS) databinfoGW2visGWDB, Conversion of an infoGW object to a GWmaster object compatible with the visGWDB software
An R groundwater-data processing utility for manipulating, veracity checking, and converting an 'infoGW' object to the 'GWmaster' object for the visGWDB software with demonstration for the Mississippi River Valley alluvial aquiferMGBT, Multiple Grubbs-Beck low-outlier test
The multiple Grubbs-Beck low-outlier test on positively distributed data is supported along, and utilities provided for noninterpretive U.S. Geological Survey (USGS) annual peak-streamflow data processing.Source code in R to quality assure, plot, summarize, interpolate, and extend groundwater-level information, visGWDB---Groundwater-level informatics with demonstration for the Mississippi River Valley alluvial aquifer
This page contains extensive source code in the R language supporting groundwater level informatics, and the entry point is the script visGWDB.R. The approximately 4,000 lines of aggregate code requires also extensive external dependencies. The code provides for near arbitrary-scale information processing of observations or recordings of water levels associated groundwater resources. The processin
*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