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
Modeling and Projecting the Influence of Climate Change on Texas Surface Waters and their Aquatic Biotic Communities
Water scarcity is a growing concern in Texas, where surface water is derived almost entirely from rainfall. Changes in air temperature and precipitation patterns associated with global climate change are anticipated to regionally affect the quality and quantity of inland surface waters and consequently their suitability as habitat for freshwater life. In addition to directly affecting resident org
Filter Total Items: 15
Quality Assurance of Water-Level Records from Wells in the Chicot aquifer system in southwestern Louisiana Department of Natural Resources' Stategic Online Natural Resources Information System (SONRIS)
The Louisiana Department of Natural Resources’ (LaDNR) Strategic Online Natural Resources Information System (SONRIS) is a repository for recent (1930–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 LaDNR. This data set consists of wel
Groundwater levels and other covariates useful for statistical modeling for the Mississippi River Valley Alluvial aquifer, Mississippi Alluvial Plain
Groundwater-level data, in conjunction with attendant metadata and covariates (predictor variables) data, for the Mississippi River Valley alluvial aquifer (MRVA) are used to support statistical and process-based numerical modeling. This page represents a collection of groundwater-level data within the expanse of the Mississippi Alluvial Plain (MAP) (Painter and Westerman, 2018) and are derived fr
Datasets used to map the potentiometric surface, Mississippi River Valley alluvial aquifer, spring 2020
A potentiometric-surface map for spring 2020 was created for the Mississippi River Valley alluvial aquifer (MRVA), 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. The location and water-level altitude in feet for these wells and streamgages in spring 2020
Quality Assurance of Water-Level Records from Wells in the Mississippi River Valley Alluvial Aquifer in Missouri from the Missouri Department of Natural Resources Well Information Management System (WIMS) from July 28, 2016, through December 31, 2018
This dataset contains the final water-level records (334) that met all threshold criteria and had an absolute residual (ABS_PSEUDO_LEV) of less than 20 feet. The threshold of 20 feet was selected based on water-level changes of the U.S. Geological Survey groundwater site 363551090152801 Qulin, in the Mississippi River Valley alluvial aquifer. This final dataset is considered a best representation
Geospatial data for select U.S. Geological Survey streamflow-gaging stations in New Mexico, Oklahoma, and Texas useful for statistical study of annual peak streamflows in and near Texas
This dataset provides watershed delineations for 1,703 U.S. Geological Survey (USGS) streamgaging stations (gages) for geospatial statistical study of peak streamflows in and near Texas. These streamgaging stations are in Texas, Oklahoma, and New Mexico (east of the Great Continental Divide) with some of the watersheds associated with the 1,703 streamgaging stations extending into several surround
Estimated quantiles of decadal flow-duration curves using selected probability distributions fit to no-flow fractions and L-moments predicted for streamgages and for pour points of level-12 hydrologic unit codes in the southeastern United States, 1950-201
Using previously published (Robinson and others, 2019) no-flow fractions and L-moments of nonzero streamflow from decadal streamflow flow-duration analysis (daily mean streamflow), probability distributions were fit to provide 27 estimated quantiles of decadal flow-duration curves, and hence the probability distributions are a form of parametric modeling that ensures monotonicity of the quantiles
Attributions for nonstationary peak streamflow records across the conterminous United States, 1941-2015 and 1966-2015
The U.S. Geological Survey Dakota Water Science Center, in cooperation with the Federal Highway Administration, analyzed annual peak-flow data to determine if trends are present and provide attribution of trends where possible. Work for the national trend attributions for nonstationary annual peak-flow records was broken into seven regions that are loosely based off of two-digit hydrologic unit wa
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
Altitude of the potentiometric surface in the Mississippi River Valley alluvial aquifer, spring 2020
The purpose of this report is to present a potentiometric-surface map for the Mississippi River Valley alluvial aquifer (MRVA). The source data for the map were groundwater-altitude data from wells measured manually or continuously generally in spring 2020 and from the altitude of the top of the water surface measured generally on April 9, 2020, in rivers in the area.
Altitude of the potentiometric surface in the Mississippi River Valley alluvial aquifer, spring 2018
A potentiometric-surface map for spring 2018 was created for the Mississippi River Valley alluvial (MRVA) aquifer using available groundwater-altitude data from 1,126 wells completed in the MRVA aquifer and from the altitude of the top of the water surface in area rivers from 66 streamgages. Personnel from Arkansas Natural Resources Commission, Arkansas Department of Health, Arkansas Geological Su
Potentiometric surface of the Mississippi River Valley alluvial aquifer, spring 2016
A potentiometric surface map for spring 2016 was created for the Mississippi River Valley alluvial (MRVA) aquifer using selected 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 measured more than one time or continually; streamgages are typically operated co
Filter Total Items: 67
Simulation of monthly mean and monthly base flow of streamflow using random forests for the Mississippi River Alluvial Plain, 1901 to 2018
Improved simulations of streamflow and base flow for selected sites within and adjacent to the Mississippi River Alluvial Plain area are important for modeling groundwater flow because surface-water flows have a substantial effect on groundwater levels. One method for simulating streamflow and base flow, random forest (RF) models, was developed from the data at gaged sites and, in turn, was used t
Authors
Benjamin J. Dietsch, William H. Asquith, Brian K. Breaker, Stephen M. Westenbroek, Wade H. Kress
Generalized additive model estimation of no-flow fractions and L-moments to support flow-duration curve quantile estimation using selected probability distributions for bay and estuary restoration in the Gulf States
Censored and uncensored generalized additive models (GAMs) were developed using streamflow data from 941 U.S. Geological Survey streamflow-gaging stations (streamgages) to predict decadal statistics of daily streamflow for streams draining to the Gulf of Mexico. The modeled decadal statistics comprise no-flow fractions and L-moments of logarithms of nonzero streamflow for six decades (1950–2009).
Authors
Elena Crowley-Ornelas, William H. Asquith, Scott C. Worland
Technique to estimate generalized skew coefficients of annual peak streamflow for natural watershed conditions in Texas, Oklahoma, and eastern New Mexico
Reliable information about the frequency of annual peak streamflow is needed for floodplain management, objective assessment of flood risk, and cost-effective design of dams, levees, other flood-control structures, and roads, bridges, and culverts. Generalized skew coefficients are among the data needed for log-Pearson type III peak-streamflow frequency analyses of annual peak streamflows. A techn
Authors
William H. Asquith, Monica Veale Yesildirek, Raven N. Landers, Theodore G Cleveland, Zheng N. Fang, Jiaqi Zhang
Regional regression equations for estimation of four hydraulic properties of streams at approximate bankfull conditions for different ecoregions in Texas
The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, assessed statistical relations between hydraulic properties of streams at approximate bankfull conditions for different ecological regions (ecoregions) in Texas. Data from more than 103,000 records of measured discharge and ancillary hydraulic properties were assembled from summaries of discharge measurements for 424
Authors
William H. Asquith, John D. Gordon, David S. Wallace
Methods to quality assure, plot, summarize, interpolate, and extend groundwater-level information—Examples for the Mississippi River Valley alluvial aquifer
Large-scale computational investigations of groundwater levels are proposed to accelerate science delivery through a workflow spanning database assembly, statistics, and information synthesis and packaging. A water-availability study of the Mississippi River alluvial plain, and particularly the Mississippi River Valley alluvial aquifer (MRVA), is ongoing. Software (visGWDBmrva) has been released a
Authors
William H. Asquith, Ronald C. Seanor, Virginia L. McGuire, Wade Kress
The use of support vectors from support vector machines for hydrometeorologic monitoring network analyses
Hydrometeorologic monitoring networks are ubiquitous in contemporary earth-system science. Network stakeholders often inquire about the importance of sites and their locations when discussing funding and monitoring design. Support vector machines (SVMs) can be useful by their assigning each monitoring site as either a support or nonsupport vector. A potentiometric surface was created from syntheti
Authors
William H. Asquith
Copula theory as a generalized framework for flow-duration curve-based streamflow estimates in ungaged and partially gaged catchments
Flow‐duration curve (FDC) based streamflow estimation methods involve estimating an FDC at an ungaged or partially gaged location and using the time series of nonexceedance probabilities estimated from donor streamgage sites to generate estimates of streamflow. We develop a mathematical framework to illustrate the connection between copulas and prior FDC‐based approaches. The performance of copula
Authors
Scott C. Worland, Scott Steinschneider, William Farmer, William H. Asquith, Rodney White
Prediction and inference of flow-duration curves using multi-output neural networks
We develop multi-output neural network models (MNNs) to predict flow-duration curves (FDCs) in 9,203 ungaged locations in the Southeastern United States for six decades between 1950-2009. The model architecture contains multiple response variables in the output layer that correspond to individual quantiles along the FDC. During training, predictions are made for each quantile, and a combined loss
Authors
Scott C. Worland, Scott Steinschneider, William H. Asquith, Rodney Knight, Michael E. Wieczorek
Characterizing groundwater/surface-water interaction using hydrograph-separation techniques and groundwater-level data throughout the Mississippi Delta, USA
The Mississippi Delta, located in northwest Mississippi, is an area dense with industrial-level agriculture sustained by groundwater-dependent irrigation supplied by the Mississippi River Valley Alluvial aquifer (alluvial aquifer). The Delta provides agricultural commodities across the United States and around the world. Observed declines in groundwater altitudes and streamflow contemporaneous wit
Authors
Courtney D. Killian, William H. Asquith, Jeannie R. B. Barlow, Gardner C. Bent, Wade Kress, Paul M. Barlow, Darrel W. Schmitz
Annual and approximately quarterly series peak streamflow derived from interpretations of indirect measurements for a crest-stage gage network in Texas through water year 2015
In 2006, the U.S. Geological Survey (USGS), incooperation with the Texas Department of Transportation,began collecting annual and approximately quarterly seriespeak-streamflow data at streamflow-gaging stations in smalltomedium-sized watersheds in central and western Texasas part of a crest-stage gage (CSG) network, along withselected flood-hydrograph data at a subset of these stations.CSGs record
Authors
William H. Asquith, Glenn R. Harwell, Karl E. Winters
Application of at-site peak-streamflow frequency analyses for very low annual exceedance probabilities
The U.S. Geological Survey (USGS), in cooperation with the U.S. Nuclear Regulatory Commission, has investigated statistical methods for probabilistic flood hazard assessment to provide guidance on very low annual exceedance probability (AEP) estimation of peak-streamflow frequency and the quantification of corresponding uncertainties using streamgage-specific data. The term “very low AEP” implies
Authors
William H. Asquith, Julie E. Kiang, Timothy A. Cohn
Refining previous estimates of groundwater outflows from the Medina/Diversion Lake system, San Antonio area, Texas
IntroductionIn 2016, the U.S. Geological Survey (USGS), in cooperation with the San Antonio Water System, began a study to refine previously derived estimates of groundwater outflows from Medina and Diversion Lakes in south-central Texas near San Antonio. When full, Medina and Diversion Lakes (hereinafter referred to as the Medina/Diversion Lake system) (fig. 1) impound approximately 255,000 acre-
Authors
Richard N. Slattery, William H. Asquith, John D. Gordon
aqtsra, Utilities for preprocessing raw and approved unit-value time-series hydrometeorological data before statistical endeavors
The aqtsra package in the R language provides a light-weight utility for merging U.S. Geological Survey National Water Information System (NWIS) flat-file tables of raw and approved unit-value time-series data from the AQUARIUS Time-Series software. Provision is made for parsing time stamps, insertion of the day fraction into the year, and days since last site visit among other limited data-inspec
covMRVAgen1, Source code for construction of covariates bound to monthly groundwater levels for purposes of statistical modeling of water levels in the Mississippi River Valley alluvial aquifer
The covMRVAgen1 repository contains R (primarily), Mermaid, Perl, and Python language source code that can be used the construction of input tables of monthly groundwater levels (response variable) and predictor variables (covariates) for statistical modeling of water levels in the Mississippi River Valley alluvial aquifer within the Mississippi Alluvial Plain, south-central United States. The sou
scNIDaregis, Geospatial processing of dams in the United States from the National Inventory of Dams with a state-level aggregation scheme, demonstrated for selected dams in eight states in south-central region of the United States, and post-processing fea
This repository contains R language source code used to read eight tab-delimited text files of state-level instances of the U.S. Army Corps of Engineers National Inventory of Dams (NID). The text file were generated from spreadsheets, which themselves are column-trimmed versions of spreadsheets that were downloaded from the public interface to the NID. The focus of the repository is on reservoir s
Source code in R for creation of regional regression equations for estimation of four hydraulic properties of streams at approximate bankfull conditions for different ecoregions in Texas associated with U.S. Geological Survey Scientific Investigations Rep
This repository contains R language source code used for creation of regional regression equations for estimation of four hydraulic properties of streams at approximate bankfull conditions for different ecoregions in Texas. This code is in support of the following study: Asquith, W.H., Gordon, J.D., and Wallace, D.S., 2020, Regional regression equations for estimation of four hydraulic properties
trajPipeFlow, Discharge from horizontal and vertical flowing pipes by trajectory methods
The trajPipeFlow package in the R language provides functions for computation of discharge from horizontal and vertical flowing pipes using trajectory methods of the U.S. Bureau of Reclamation Water Measurement Manual (2001, chap. 14, sec. 13).
RESTORE/fdclmrpplo, Source code for estimation of L-moments and percent no-flow conditions for decadal flow-duration curves and estimation at level-12 hydrologic unit codes along with other statistical computations
The RESTORE/fdclmrpplo repository contains R language source code used for estimation of the L-moments and percent no-flow conditions (no-flow fractions) for decadal flow-duration curves and estimation at streamgages and level-12 hydrologic unit codes using generalized additive models and censored generalized additive models. The source code is designed to streamline the workflow for the Gulf Coas
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
Modeling and Projecting the Influence of Climate Change on Texas Surface Waters and their Aquatic Biotic Communities
Water scarcity is a growing concern in Texas, where surface water is derived almost entirely from rainfall. Changes in air temperature and precipitation patterns associated with global climate change are anticipated to regionally affect the quality and quantity of inland surface waters and consequently their suitability as habitat for freshwater life. In addition to directly affecting resident org - Data
Filter Total Items: 15
Quality Assurance of Water-Level Records from Wells in the Chicot aquifer system in southwestern Louisiana Department of Natural Resources' Stategic Online Natural Resources Information System (SONRIS)
The Louisiana Department of Natural Resources’ (LaDNR) Strategic Online Natural Resources Information System (SONRIS) is a repository for recent (1930–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 LaDNR. This data set consists of welGroundwater levels and other covariates useful for statistical modeling for the Mississippi River Valley Alluvial aquifer, Mississippi Alluvial Plain
Groundwater-level data, in conjunction with attendant metadata and covariates (predictor variables) data, for the Mississippi River Valley alluvial aquifer (MRVA) are used to support statistical and process-based numerical modeling. This page represents a collection of groundwater-level data within the expanse of the Mississippi Alluvial Plain (MAP) (Painter and Westerman, 2018) and are derived frDatasets used to map the potentiometric surface, Mississippi River Valley alluvial aquifer, spring 2020
A potentiometric-surface map for spring 2020 was created for the Mississippi River Valley alluvial aquifer (MRVA), 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. The location and water-level altitude in feet for these wells and streamgages in spring 2020Quality Assurance of Water-Level Records from Wells in the Mississippi River Valley Alluvial Aquifer in Missouri from the Missouri Department of Natural Resources Well Information Management System (WIMS) from July 28, 2016, through December 31, 2018
This dataset contains the final water-level records (334) that met all threshold criteria and had an absolute residual (ABS_PSEUDO_LEV) of less than 20 feet. The threshold of 20 feet was selected based on water-level changes of the U.S. Geological Survey groundwater site 363551090152801 Qulin, in the Mississippi River Valley alluvial aquifer. This final dataset is considered a best representationGeospatial data for select U.S. Geological Survey streamflow-gaging stations in New Mexico, Oklahoma, and Texas useful for statistical study of annual peak streamflows in and near Texas
This dataset provides watershed delineations for 1,703 U.S. Geological Survey (USGS) streamgaging stations (gages) for geospatial statistical study of peak streamflows in and near Texas. These streamgaging stations are in Texas, Oklahoma, and New Mexico (east of the Great Continental Divide) with some of the watersheds associated with the 1,703 streamgaging stations extending into several surroundEstimated quantiles of decadal flow-duration curves using selected probability distributions fit to no-flow fractions and L-moments predicted for streamgages and for pour points of level-12 hydrologic unit codes in the southeastern United States, 1950-201
Using previously published (Robinson and others, 2019) no-flow fractions and L-moments of nonzero streamflow from decadal streamflow flow-duration analysis (daily mean streamflow), probability distributions were fit to provide 27 estimated quantiles of decadal flow-duration curves, and hence the probability distributions are a form of parametric modeling that ensures monotonicity of the quantilesAttributions for nonstationary peak streamflow records across the conterminous United States, 1941-2015 and 1966-2015
The U.S. Geological Survey Dakota Water Science Center, in cooperation with the Federal Highway Administration, analyzed annual peak-flow data to determine if trends are present and provide attribution of trends where possible. Work for the national trend attributions for nonstationary annual peak-flow records was broken into seven regions that are loosely based off of two-digit hydrologic unit waQuality 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-makers - Maps
Altitude of the potentiometric surface in the Mississippi River Valley alluvial aquifer, spring 2020
The purpose of this report is to present a potentiometric-surface map for the Mississippi River Valley alluvial aquifer (MRVA). The source data for the map were groundwater-altitude data from wells measured manually or continuously generally in spring 2020 and from the altitude of the top of the water surface measured generally on April 9, 2020, in rivers in the area.Altitude of the potentiometric surface in the Mississippi River Valley alluvial aquifer, spring 2018
A potentiometric-surface map for spring 2018 was created for the Mississippi River Valley alluvial (MRVA) aquifer using available groundwater-altitude data from 1,126 wells completed in the MRVA aquifer and from the altitude of the top of the water surface in area rivers from 66 streamgages. Personnel from Arkansas Natural Resources Commission, Arkansas Department of Health, Arkansas Geological SuPotentiometric surface of the Mississippi River Valley alluvial aquifer, spring 2016
A potentiometric surface map for spring 2016 was created for the Mississippi River Valley alluvial (MRVA) aquifer using selected 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 measured more than one time or continually; streamgages are typically operated co - Publications
Filter Total Items: 67
Simulation of monthly mean and monthly base flow of streamflow using random forests for the Mississippi River Alluvial Plain, 1901 to 2018
Improved simulations of streamflow and base flow for selected sites within and adjacent to the Mississippi River Alluvial Plain area are important for modeling groundwater flow because surface-water flows have a substantial effect on groundwater levels. One method for simulating streamflow and base flow, random forest (RF) models, was developed from the data at gaged sites and, in turn, was used tAuthorsBenjamin J. Dietsch, William H. Asquith, Brian K. Breaker, Stephen M. Westenbroek, Wade H. KressGeneralized additive model estimation of no-flow fractions and L-moments to support flow-duration curve quantile estimation using selected probability distributions for bay and estuary restoration in the Gulf States
Censored and uncensored generalized additive models (GAMs) were developed using streamflow data from 941 U.S. Geological Survey streamflow-gaging stations (streamgages) to predict decadal statistics of daily streamflow for streams draining to the Gulf of Mexico. The modeled decadal statistics comprise no-flow fractions and L-moments of logarithms of nonzero streamflow for six decades (1950–2009).AuthorsElena Crowley-Ornelas, William H. Asquith, Scott C. WorlandTechnique to estimate generalized skew coefficients of annual peak streamflow for natural watershed conditions in Texas, Oklahoma, and eastern New Mexico
Reliable information about the frequency of annual peak streamflow is needed for floodplain management, objective assessment of flood risk, and cost-effective design of dams, levees, other flood-control structures, and roads, bridges, and culverts. Generalized skew coefficients are among the data needed for log-Pearson type III peak-streamflow frequency analyses of annual peak streamflows. A technAuthorsWilliam H. Asquith, Monica Veale Yesildirek, Raven N. Landers, Theodore G Cleveland, Zheng N. Fang, Jiaqi ZhangRegional regression equations for estimation of four hydraulic properties of streams at approximate bankfull conditions for different ecoregions in Texas
The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, assessed statistical relations between hydraulic properties of streams at approximate bankfull conditions for different ecological regions (ecoregions) in Texas. Data from more than 103,000 records of measured discharge and ancillary hydraulic properties were assembled from summaries of discharge measurements for 424AuthorsWilliam H. Asquith, John D. Gordon, David S. WallaceMethods to quality assure, plot, summarize, interpolate, and extend groundwater-level information—Examples for the Mississippi River Valley alluvial aquifer
Large-scale computational investigations of groundwater levels are proposed to accelerate science delivery through a workflow spanning database assembly, statistics, and information synthesis and packaging. A water-availability study of the Mississippi River alluvial plain, and particularly the Mississippi River Valley alluvial aquifer (MRVA), is ongoing. Software (visGWDBmrva) has been released aAuthorsWilliam H. Asquith, Ronald C. Seanor, Virginia L. McGuire, Wade KressThe use of support vectors from support vector machines for hydrometeorologic monitoring network analyses
Hydrometeorologic monitoring networks are ubiquitous in contemporary earth-system science. Network stakeholders often inquire about the importance of sites and their locations when discussing funding and monitoring design. Support vector machines (SVMs) can be useful by their assigning each monitoring site as either a support or nonsupport vector. A potentiometric surface was created from synthetiAuthorsWilliam H. AsquithCopula theory as a generalized framework for flow-duration curve-based streamflow estimates in ungaged and partially gaged catchments
Flow‐duration curve (FDC) based streamflow estimation methods involve estimating an FDC at an ungaged or partially gaged location and using the time series of nonexceedance probabilities estimated from donor streamgage sites to generate estimates of streamflow. We develop a mathematical framework to illustrate the connection between copulas and prior FDC‐based approaches. The performance of copulaAuthorsScott C. Worland, Scott Steinschneider, William Farmer, William H. Asquith, Rodney WhitePrediction and inference of flow-duration curves using multi-output neural networks
We develop multi-output neural network models (MNNs) to predict flow-duration curves (FDCs) in 9,203 ungaged locations in the Southeastern United States for six decades between 1950-2009. The model architecture contains multiple response variables in the output layer that correspond to individual quantiles along the FDC. During training, predictions are made for each quantile, and a combined lossAuthorsScott C. Worland, Scott Steinschneider, William H. Asquith, Rodney Knight, Michael E. WieczorekCharacterizing groundwater/surface-water interaction using hydrograph-separation techniques and groundwater-level data throughout the Mississippi Delta, USA
The Mississippi Delta, located in northwest Mississippi, is an area dense with industrial-level agriculture sustained by groundwater-dependent irrigation supplied by the Mississippi River Valley Alluvial aquifer (alluvial aquifer). The Delta provides agricultural commodities across the United States and around the world. Observed declines in groundwater altitudes and streamflow contemporaneous witAuthorsCourtney D. Killian, William H. Asquith, Jeannie R. B. Barlow, Gardner C. Bent, Wade Kress, Paul M. Barlow, Darrel W. SchmitzAnnual and approximately quarterly series peak streamflow derived from interpretations of indirect measurements for a crest-stage gage network in Texas through water year 2015
In 2006, the U.S. Geological Survey (USGS), incooperation with the Texas Department of Transportation,began collecting annual and approximately quarterly seriespeak-streamflow data at streamflow-gaging stations in smalltomedium-sized watersheds in central and western Texasas part of a crest-stage gage (CSG) network, along withselected flood-hydrograph data at a subset of these stations.CSGs recordAuthorsWilliam H. Asquith, Glenn R. Harwell, Karl E. WintersApplication of at-site peak-streamflow frequency analyses for very low annual exceedance probabilities
The U.S. Geological Survey (USGS), in cooperation with the U.S. Nuclear Regulatory Commission, has investigated statistical methods for probabilistic flood hazard assessment to provide guidance on very low annual exceedance probability (AEP) estimation of peak-streamflow frequency and the quantification of corresponding uncertainties using streamgage-specific data. The term “very low AEP” impliesAuthorsWilliam H. Asquith, Julie E. Kiang, Timothy A. CohnRefining previous estimates of groundwater outflows from the Medina/Diversion Lake system, San Antonio area, Texas
IntroductionIn 2016, the U.S. Geological Survey (USGS), in cooperation with the San Antonio Water System, began a study to refine previously derived estimates of groundwater outflows from Medina and Diversion Lakes in south-central Texas near San Antonio. When full, Medina and Diversion Lakes (hereinafter referred to as the Medina/Diversion Lake system) (fig. 1) impound approximately 255,000 acre-AuthorsRichard N. Slattery, William H. Asquith, John D. Gordon - Software
aqtsra, Utilities for preprocessing raw and approved unit-value time-series hydrometeorological data before statistical endeavors
The aqtsra package in the R language provides a light-weight utility for merging U.S. Geological Survey National Water Information System (NWIS) flat-file tables of raw and approved unit-value time-series data from the AQUARIUS Time-Series software. Provision is made for parsing time stamps, insertion of the day fraction into the year, and days since last site visit among other limited data-inspeccovMRVAgen1, Source code for construction of covariates bound to monthly groundwater levels for purposes of statistical modeling of water levels in the Mississippi River Valley alluvial aquifer
The covMRVAgen1 repository contains R (primarily), Mermaid, Perl, and Python language source code that can be used the construction of input tables of monthly groundwater levels (response variable) and predictor variables (covariates) for statistical modeling of water levels in the Mississippi River Valley alluvial aquifer within the Mississippi Alluvial Plain, south-central United States. The souscNIDaregis, Geospatial processing of dams in the United States from the National Inventory of Dams with a state-level aggregation scheme, demonstrated for selected dams in eight states in south-central region of the United States, and post-processing fea
This repository contains R language source code used to read eight tab-delimited text files of state-level instances of the U.S. Army Corps of Engineers National Inventory of Dams (NID). The text file were generated from spreadsheets, which themselves are column-trimmed versions of spreadsheets that were downloaded from the public interface to the NID. The focus of the repository is on reservoir sSource code in R for creation of regional regression equations for estimation of four hydraulic properties of streams at approximate bankfull conditions for different ecoregions in Texas associated with U.S. Geological Survey Scientific Investigations Rep
This repository contains R language source code used for creation of regional regression equations for estimation of four hydraulic properties of streams at approximate bankfull conditions for different ecoregions in Texas. This code is in support of the following study: Asquith, W.H., Gordon, J.D., and Wallace, D.S., 2020, Regional regression equations for estimation of four hydraulic propertiestrajPipeFlow, Discharge from horizontal and vertical flowing pipes by trajectory methods
The trajPipeFlow package in the R language provides functions for computation of discharge from horizontal and vertical flowing pipes using trajectory methods of the U.S. Bureau of Reclamation Water Measurement Manual (2001, chap. 14, sec. 13).RESTORE/fdclmrpplo, Source code for estimation of L-moments and percent no-flow conditions for decadal flow-duration curves and estimation at level-12 hydrologic unit codes along with other statistical computations
The RESTORE/fdclmrpplo repository contains R language source code used for estimation of the L-moments and percent no-flow conditions (no-flow fractions) for decadal flow-duration curves and estimation at streamgages and level-12 hydrologic unit codes using generalized additive models and censored generalized additive models. The source code is designed to streamline the workflow for the Gulf Coasutc2nwislocal, 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