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
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 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), in cooperation with the Texas Department of Transportation, began collecting annual and approximately quarterly series peak-streamflow data at streamflow-gaging stations in smallto medium-sized watersheds in central and western Texas as part of a crest-stage gage (CSG) network, along with selected flood-hydrograph data at a subset of these...
Authors
William H. Asquith, Glenn R. Harwell, Karl E. Winters
Application of at-site peak-streamflow frequency analyses for very low annual exceedance probabilities 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...
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 Refining previous estimates of groundwater outflows from the Medina/Diversion Lake system, San Antonio area, Texas
Introduction In 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...
Authors
Richard N. Slattery, William H. Asquith, John D. Gordon
Long-term trends in reservoir water quality and quantity in two major river basins of the southern Great Plains 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...
Authors
D. Dawson, Matthew M. VanLandeghem, William H. Asquith, Reynaldo Patino
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 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...
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 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...
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 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...
Authors
William H. Asquith, Johnathan R. Bumgarner
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 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...
Authors
William H. Asquith
Parameter estimation for the 4-parameter Asymmetric Exponential Power distribution by the method of L-moments using R 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...
Authors
William H. Asquith
Return period adjustment for runoff coefficients based on analysis in undeveloped Texas watersheds 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...
Authors
Nirajan Dhakal, Xing Fang, William H. Asquith, Theodore G. Cleveland, David B. Thompson
Empirical flow parameters : a tool for hydraulic model validity 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...
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 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...
Authors
William H. Asquith, George R. Herrmann, Theodore G. Cleveland
Filter Total Items: 48
Modeled daily salinity derived from multiple machine learning methodologies and generalized additive models for three salinity monitoring sites in Mobile Bay, northern Gulf of Mexico, 1980–2021 Modeled daily salinity derived from multiple machine learning methodologies and generalized additive models for three salinity monitoring sites in Mobile Bay, northern Gulf of Mexico, 1980–2021
Results from generalized additive models (GAM), random forest models (RFM), and cubist models (CUB) for three Dauphin Island Sealab (DIS) operated salinity sites in Mobile Bay are reported in this data release. These sites included Meaher Park (DIS:MHPA1), Middle Bay Lighthouse (DIS:MBLA1), and Dauphin Island (DIS:DPIA1). The constructed models predicted a 42-year daily salinity record...
infoGWauxs, Auxiliary methods for infoGW and similar groundwater level data objects and other helpful utilities infoGWauxs, Auxiliary methods for infoGW and similar groundwater level data objects and other helpful utilities
The infoGWauxs package in the R language provides auxiliary methods for data merging, duplicate-record removal, and monthly rollup of groundwater levels in the so-called infoGW or GWmaster data objects. These data structures are particularly well suited for statistical analyses of groundwater levels. This package is part of a greater body of data processors oriented around the infoGW...
Quality assurance of water levels in the Mississippi River Valley alluvial aquifer in Louisiana from the Louisiana Department of Natural Resources' Strategic Online Natural Resources Information System (SONRIS) Quality assurance of water levels in the Mississippi River Valley alluvial aquifer in Louisiana from the Louisiana Department of Natural Resources' Strategic Online Natural Resources Information System (SONRIS)
This data release provides several data files representing groundwater levels reported through driller's reports for the State of Louisiana Department of Natural Resources (Louisiana Department of Natural Resources, 2023) within or near the Mississippi Alluvial Plain (MAP) and (or) associated with the Mississippi River Valley alluvial aquifer (MRVA). First, a retrieval of data from the...
Quality assurance of water levels in the Mississippi River Valley alluvial aquifer in Arkansas from the Arkansas Department of Agriculture Natural Resources Division Quality assurance of water levels in the Mississippi River Valley alluvial aquifer in Arkansas from the Arkansas Department of Agriculture Natural Resources Division
This data release provides several data files representing groundwater levels reported through driller's reports for the State of Arkansas Arkansas Department of Agriculture National Resources Division (https://wise.er.usgs.gov/driller_db/) (accessed January 10, 2024) within or near the Mississippi Alluvial Plain (MAP) and (or) associated with the Mississippi River Valley alluvial...
Imputed daily salinity and associated covariates to support statistical modeling for 91 salinity monitoring sites in the northern Gulf of Mexico Imputed daily salinity and associated covariates to support statistical modeling for 91 salinity monitoring sites in the northern Gulf of Mexico
Imputed salinities from either salinity or specific conductance observations and covariate data in data structures deemed suitable for statistical modeling of salinity in near-coastal environments of the northern Gulf of Mexico are provided for 15 salinity groups. The data herein were created by the 'covardr2formodel.R' script of 'covESTUSAL software' (Asquith and others, 2023), which...
Geospatial representations of salinity monitoring site and bay and estuary group boundaries in the Gulf of Mexico Geospatial representations of salinity monitoring site and bay and estuary group boundaries in the Gulf of Mexico
The polygon datasets were created to assist in visualizing the results of salinity modeling in Gulf of Mexico estuaries and bays. Statistical algorithms (Asquith and others, 2023) were developed to predict daily salinities for 91 salinity monitoring sites (Rodgers and Swarzenski, 2019) operated by 7 agencies in near coastal United States waters of the Gulf of Mexico. These monitoring...
RESTORE/makESTUSAL, Source code for construction of various statistical models and prediction of daily salinity in coastal regions of the Gulf of Mexico, United States RESTORE/makESTUSAL, Source code for construction of various statistical models and prediction of daily salinity in coastal regions of the Gulf of Mexico, United States
The RESTORE/makESTUSAL software repository contains R language source code that can be used for the construction of various statistical models and output time series of predicted daily salinity coastal regions of the Gulf of Mexico, United States. The source code is expansive, and the repository is organizationally deep following logical organization units. One major subsystem of the...
Simulation and comparison of five estimators of variability in units of standard deviation for small samples drawn from normally distributed data Simulation and comparison of five estimators of variability in units of standard deviation for small samples drawn from normally distributed data
It is convenient to measure or estimate variation in samples or distributions in units of standard deviations. There are alternative methods of estimation of standard deviation aside from the conventional and well-known definition. Estimation of standard deviation for very small samples (as small as two), whereas not always ideal, might be useful in certain practical circumstances. A...
Study of L-kurtosis and several distribution families for prediction of uncertainty distributions, An applied software technical note concerning L-kurtosis use in daily salinity prediction from multiple machine learning methods Study of L-kurtosis and several distribution families for prediction of uncertainty distributions, An applied software technical note concerning L-kurtosis use in daily salinity prediction from multiple machine learning methods
Statistical predictions that are based on multiple machine learning (MML) methods (from including differing training regimes) produce differing predictions. When the predictions are combined to a final estimate, then there are residuals of the predictions spread around the final estimate. It is common to assume normality or near-normality of the residuals (errors), but the assumption of...
RESTORE/covESTUSAL, Source code for construction of covariates bound to daily salinity and specific conductance data for purposes of statistical modeling in coastal regions of the Gulf of Mexico, United States RESTORE/covESTUSAL, Source code for construction of covariates bound to daily salinity and specific conductance data for purposes of statistical modeling in coastal regions of the Gulf of Mexico, United States
The RESTORE/covESTUSAL software repository contains R language source code useful for the construction of input tables of daily salinity and specific conductance (response variables) from multi-agency monitoring stations and potential predictor variables (covariates) intended for reuse in statistical model construction in coastal regions of the Gulf of Mexico, United States. The source...
Datasets of depth to water, spring 2016, 2018, and 2020, and spring-to-spring water-level change 2016-18, 2018-20, and 2016-20, Mississippi River Valley alluvial aquifer Datasets of depth to water, spring 2016, 2018, and 2020, and spring-to-spring water-level change 2016-18, 2018-20, and 2016-20, Mississippi River Valley alluvial aquifer
This data release consists of 4 data sets--rasters of generalized depth to water in the Mississippi River Valley alluvial aquifer (MRVA) in spring 2016, 2018, and 2020 and a point file of the wells with water-level measurements used to create the depth to water rasters and, for each well with applicable data, the values of water-level change from spring 2016 to spring 2018, spring 2018...
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) 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...
Filter Total Items: 22
aqtsra, Utilities for preprocessing raw and approved unit-value time-series hydrometeorological data before statistical endeavors 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...
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 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...
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 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...
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 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...
trajPipeFlow, Discharge from horizontal and vertical flowing pipes by trajectory methods 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 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...
utc2nwislocal, UTC date-times to NWIS local time zones using UTC offsets 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...
infoGW2visGWDB, Conversion of an infoGW object to a GWmaster object compatible with the visGWDB software 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 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 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...
Science and Products
Filter Total Items: 70
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 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), in cooperation with the Texas Department of Transportation, began collecting annual and approximately quarterly series peak-streamflow data at streamflow-gaging stations in smallto medium-sized watersheds in central and western Texas as part of a crest-stage gage (CSG) network, along with selected flood-hydrograph data at a subset of these...
Authors
William H. Asquith, Glenn R. Harwell, Karl E. Winters
Application of at-site peak-streamflow frequency analyses for very low annual exceedance probabilities 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...
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 Refining previous estimates of groundwater outflows from the Medina/Diversion Lake system, San Antonio area, Texas
Introduction In 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...
Authors
Richard N. Slattery, William H. Asquith, John D. Gordon
Long-term trends in reservoir water quality and quantity in two major river basins of the southern Great Plains 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...
Authors
D. Dawson, Matthew M. VanLandeghem, William H. Asquith, Reynaldo Patino
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 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...
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 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...
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 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...
Authors
William H. Asquith, Johnathan R. Bumgarner
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 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...
Authors
William H. Asquith
Parameter estimation for the 4-parameter Asymmetric Exponential Power distribution by the method of L-moments using R 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...
Authors
William H. Asquith
Return period adjustment for runoff coefficients based on analysis in undeveloped Texas watersheds 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...
Authors
Nirajan Dhakal, Xing Fang, William H. Asquith, Theodore G. Cleveland, David B. Thompson
Empirical flow parameters : a tool for hydraulic model validity 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...
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 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...
Authors
William H. Asquith, George R. Herrmann, Theodore G. Cleveland
Filter Total Items: 48
Modeled daily salinity derived from multiple machine learning methodologies and generalized additive models for three salinity monitoring sites in Mobile Bay, northern Gulf of Mexico, 1980–2021 Modeled daily salinity derived from multiple machine learning methodologies and generalized additive models for three salinity monitoring sites in Mobile Bay, northern Gulf of Mexico, 1980–2021
Results from generalized additive models (GAM), random forest models (RFM), and cubist models (CUB) for three Dauphin Island Sealab (DIS) operated salinity sites in Mobile Bay are reported in this data release. These sites included Meaher Park (DIS:MHPA1), Middle Bay Lighthouse (DIS:MBLA1), and Dauphin Island (DIS:DPIA1). The constructed models predicted a 42-year daily salinity record...
infoGWauxs, Auxiliary methods for infoGW and similar groundwater level data objects and other helpful utilities infoGWauxs, Auxiliary methods for infoGW and similar groundwater level data objects and other helpful utilities
The infoGWauxs package in the R language provides auxiliary methods for data merging, duplicate-record removal, and monthly rollup of groundwater levels in the so-called infoGW or GWmaster data objects. These data structures are particularly well suited for statistical analyses of groundwater levels. This package is part of a greater body of data processors oriented around the infoGW...
Quality assurance of water levels in the Mississippi River Valley alluvial aquifer in Louisiana from the Louisiana Department of Natural Resources' Strategic Online Natural Resources Information System (SONRIS) Quality assurance of water levels in the Mississippi River Valley alluvial aquifer in Louisiana from the Louisiana Department of Natural Resources' Strategic Online Natural Resources Information System (SONRIS)
This data release provides several data files representing groundwater levels reported through driller's reports for the State of Louisiana Department of Natural Resources (Louisiana Department of Natural Resources, 2023) within or near the Mississippi Alluvial Plain (MAP) and (or) associated with the Mississippi River Valley alluvial aquifer (MRVA). First, a retrieval of data from the...
Quality assurance of water levels in the Mississippi River Valley alluvial aquifer in Arkansas from the Arkansas Department of Agriculture Natural Resources Division Quality assurance of water levels in the Mississippi River Valley alluvial aquifer in Arkansas from the Arkansas Department of Agriculture Natural Resources Division
This data release provides several data files representing groundwater levels reported through driller's reports for the State of Arkansas Arkansas Department of Agriculture National Resources Division (https://wise.er.usgs.gov/driller_db/) (accessed January 10, 2024) within or near the Mississippi Alluvial Plain (MAP) and (or) associated with the Mississippi River Valley alluvial...
Imputed daily salinity and associated covariates to support statistical modeling for 91 salinity monitoring sites in the northern Gulf of Mexico Imputed daily salinity and associated covariates to support statistical modeling for 91 salinity monitoring sites in the northern Gulf of Mexico
Imputed salinities from either salinity or specific conductance observations and covariate data in data structures deemed suitable for statistical modeling of salinity in near-coastal environments of the northern Gulf of Mexico are provided for 15 salinity groups. The data herein were created by the 'covardr2formodel.R' script of 'covESTUSAL software' (Asquith and others, 2023), which...
Geospatial representations of salinity monitoring site and bay and estuary group boundaries in the Gulf of Mexico Geospatial representations of salinity monitoring site and bay and estuary group boundaries in the Gulf of Mexico
The polygon datasets were created to assist in visualizing the results of salinity modeling in Gulf of Mexico estuaries and bays. Statistical algorithms (Asquith and others, 2023) were developed to predict daily salinities for 91 salinity monitoring sites (Rodgers and Swarzenski, 2019) operated by 7 agencies in near coastal United States waters of the Gulf of Mexico. These monitoring...
RESTORE/makESTUSAL, Source code for construction of various statistical models and prediction of daily salinity in coastal regions of the Gulf of Mexico, United States RESTORE/makESTUSAL, Source code for construction of various statistical models and prediction of daily salinity in coastal regions of the Gulf of Mexico, United States
The RESTORE/makESTUSAL software repository contains R language source code that can be used for the construction of various statistical models and output time series of predicted daily salinity coastal regions of the Gulf of Mexico, United States. The source code is expansive, and the repository is organizationally deep following logical organization units. One major subsystem of the...
Simulation and comparison of five estimators of variability in units of standard deviation for small samples drawn from normally distributed data Simulation and comparison of five estimators of variability in units of standard deviation for small samples drawn from normally distributed data
It is convenient to measure or estimate variation in samples or distributions in units of standard deviations. There are alternative methods of estimation of standard deviation aside from the conventional and well-known definition. Estimation of standard deviation for very small samples (as small as two), whereas not always ideal, might be useful in certain practical circumstances. A...
Study of L-kurtosis and several distribution families for prediction of uncertainty distributions, An applied software technical note concerning L-kurtosis use in daily salinity prediction from multiple machine learning methods Study of L-kurtosis and several distribution families for prediction of uncertainty distributions, An applied software technical note concerning L-kurtosis use in daily salinity prediction from multiple machine learning methods
Statistical predictions that are based on multiple machine learning (MML) methods (from including differing training regimes) produce differing predictions. When the predictions are combined to a final estimate, then there are residuals of the predictions spread around the final estimate. It is common to assume normality or near-normality of the residuals (errors), but the assumption of...
RESTORE/covESTUSAL, Source code for construction of covariates bound to daily salinity and specific conductance data for purposes of statistical modeling in coastal regions of the Gulf of Mexico, United States RESTORE/covESTUSAL, Source code for construction of covariates bound to daily salinity and specific conductance data for purposes of statistical modeling in coastal regions of the Gulf of Mexico, United States
The RESTORE/covESTUSAL software repository contains R language source code useful for the construction of input tables of daily salinity and specific conductance (response variables) from multi-agency monitoring stations and potential predictor variables (covariates) intended for reuse in statistical model construction in coastal regions of the Gulf of Mexico, United States. The source...
Datasets of depth to water, spring 2016, 2018, and 2020, and spring-to-spring water-level change 2016-18, 2018-20, and 2016-20, Mississippi River Valley alluvial aquifer Datasets of depth to water, spring 2016, 2018, and 2020, and spring-to-spring water-level change 2016-18, 2018-20, and 2016-20, Mississippi River Valley alluvial aquifer
This data release consists of 4 data sets--rasters of generalized depth to water in the Mississippi River Valley alluvial aquifer (MRVA) in spring 2016, 2018, and 2020 and a point file of the wells with water-level measurements used to create the depth to water rasters and, for each well with applicable data, the values of water-level change from spring 2016 to spring 2018, spring 2018...
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) 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...
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aqtsra, Utilities for preprocessing raw and approved unit-value time-series hydrometeorological data before statistical endeavors 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...
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 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...
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 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...
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 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...
trajPipeFlow, Discharge from horizontal and vertical flowing pipes by trajectory methods 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 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...
utc2nwislocal, UTC date-times to NWIS local time zones using UTC offsets 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...
infoGW2visGWDB, Conversion of an infoGW object to a GWmaster object compatible with the visGWDB software 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 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 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...
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