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Andrew T Leaf

Andrew Leaf is a Hydrologist at the Upper Midwest Water Science Center.

AREAS OF EXPERTISE

  • groundwater flow modeling
  • simulation of groundwater-surface water interactions
  • model calibration / parameter estimation
  • application of GIS and the python programming language to hydrologic modeling and data analysis
  • distributed temperature sensing

 

CURRENT PROJECTS

  • Mississippi Alluvial Plain (MAP) Regional Water Availability Study
  • FloPy
  • Central Sands Lake Study
  • Coastal Lowlands Aquifer System Regional Groundwater Availability Study
  • rOpen - Open landscape nitrate retention mapping
  • Groundwater-surface water interactions in the Bad River Watershed, Wisconsin.
  • Field investigation of Haskell Lake water balance and subsurface lithology, Lac du Flambeau Reservation, WI.
  • Other project and science support, teaching, and outreach as requested

 

ACADEMIC AND PROFESSIONAL SERVICE

Reviewer for Groundwater, Water Resources Research, Geophysical Research Letters, Environmental Modeling and Software and various USGS publications.

2016 to present - Member, State of Wisconsin Groundwater Coordinating Council Research and Monitoring Subcommittee

2015 to present - American Water Resources Association Wisconsin Section Board (President Elect)

 

TEACHING

GW1774-Introduction to Python for Hydrologic Modeling - USGS course given to government and academic professionals, Feb 26-Mar 2, 2018, Lakewood, CO, Co-instructors: M.N. Fienen, J. D. Hughes, and C.D Langevin; April 4-8, 2016 Madison, WI. Co-instructors: M.N. Fienen and J. D. Hughes

General Python course given to DOI scientists at the California Volcano Observatory, Menlo Park, CA, July 25-28, 2017. Co-instructor: M.N. Fienen

Geospatial Python course given to DOI scientists at the Upper Midwest Environmental Science Center in La Crosse, WI, Nov. 15-17, 2017. Co-instructor: M.N. Fienen

Understanding and Evaluating Groundwater Flow Models course given to EPA and tribal environmental staff, March 8-9, 2015, Fond du Lac, MN and April 6-8, Chicago, IL. Co-instructors: D.T. Feinstein and R.J. Hunt.

 

CODE/SOFTWARE DEVELOPMENT

Contributor to FloPy, SFRmaker and other open-source software projects for improving the quality, reproducibility and efficiency of hydrologic models (https://github.com/aleaf)

 

Professional Experience

  • 2012 - present  Hydrologist, USGS Upper Midwest Water Science Center

  • 2010 - 2012  Hydrogeologist, SoundEarth Strategies, Inc., Seattle, WA

  • 2007 - 2010  Research/Teaching Assistant, University of Wisconsin-Madison, Dept. of Geoscience

Education and Certifications

  • M.S., Hydrogeology - University of Wisconsin-Madison, 2010

  • M.S., Water Resources Management - University of Wisconsin-Madison, 2010

  • B.A., Geology and History - Gustavus Adolphus College, 2005

Abstracts and Presentations

  • Leaf, A.; Breaker, B.; Adams, R.; Dietsch, B., 2018. Improving Numerical Simulation of Streams and Shallow Groundwater in the Mississippi Alluvial Plain, Mississippi Water Resources Conference, Jackson, MS, April 3-4.

  • Leaf, A.T., 2018. A Field Investigation of a Small Drainage Lake and Contamination Plume in Northern Wisconsin, AWRA – Wisconsin Section Annual Meeting, Appleton, WI, March 8-9.

  • Leaf, Andrew T., Hunt, R.J., Christiansen, D.E., and Haj, A.E., 2017, Promise and peril of calibrating a high resolution gridded regional watershed model, MODFLOW and More conference, Golden, CO, May 21-24, 2017.

  • Leaf, Andrew T., Fienen, M.N, White, J.T. and Hunt, R.J., 2017, Data worth analysis for optimizing data collection for groundwater models, Minnesota Groundwater Association Spring Conference, Minneapolis, MN, April 26.

  • Leaf, A.T., 2017, A Distributed Temperature Sensing Investigation to Inform Lakebed Pore-Water Sampling. AWRA – Wisconsin Section Annual Meeting, Elkhart Lake, WI, March 9-10.

  • Leaf, A.T., 2015, A program for rapidly building groundwater flow models. AWRA – Wisconsin Section Annual Meeting, Oconomowoc, WI, March 5-6.

  • Leaf, A.T., Gotkowitz, M.B. and Dunning, C.P., A groundwater flow model for Columbia County, Wisconsin. AWRA – Wisconsin Section Annual Meeting, Brookfield, WI, March 7-8, 2014.

  • Leaf, A.T., Hunt, R.J. and Fienen, M.N., Teaching concepts of non-uniqueness and uncertainty in groundwater. GSA Annual Meeting, Denver, CO. October 27-30, 2013.

  • Leaf, A.T., Fienen, M.N. and Hunt, R.J., Prediction uncertainty analysis to inform additional data collection. MODFLOW and More conference, Golden, CO, June 3-5, 2013.

  • Leaf, A.T., M.N. Fienen, and R.J. Hunt, Simulation of groundwater flow and groundwater/surface water interactions in the Bad River Watershed, Wisconsin, AWRA – Wisconsin Section Annual Meeting, Brookfield, WI, March 7-8, 2013.

  • Leaf, A.T., Hart, D.J. and Bahr, J.M., Single-well thermal tracer tests using distributed temperature sensing, GSA Annual Meeting, Denver, CO, October 31-November 3, 2010.

  • Leaf, A.T. and J.M. Bahr, Water quality changes during aquifer storage recovery in the Cambrian-Ordovician Aquifer, Oak Creek, WI, GSA Annual Meeting, Houston, TX, October 5-9, 2008. (Co-winner, Best Student Paper)

Science and Products

Surface Water and Groundwater Hydrology and Temperature, Beaver Creek, Kenai Peninsula, Alaska, 2022-2023

This data release contains measurements from continuous monitors of stream temperature, groundwater temperature, and well water levels, and discrete measurements of discharge and stream shading.
By
Alaska Science Center

MODFLOW 6 models for simulating groundwater flow in the Mississippi Embayment with a focus on the Mississippi Delta

This model archive contains the model files for the MERAS 3 and Mississippi Delta groundwater flow models documented in the U.S. Geological Survey Scientific Investigations Report 2023-5100. The MERAS 3 model provides a simplified representation of groundwater flow in the Mississippi Embayment Regional Aquifer Study (MERAS) area for the period of 1900 through 2018, with the primary goal of providi
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Columbia County Groundwater Model

A MODFLOW-NWT model was used to simulate long-term, average conditions in the regional, Columbia County groundwater system since about 1970. A GFLOW model was used to estimate regional boundary fluxes to the MODFLOW-NWT model domain.
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Distributed lakebed temperature data, Haskell Lake, Wisconsin, July 28 - Aug 1, 2016

This data release consists of lakebed temperature data collected at the sediment-water interface at the north end of Haskell Lake, Lac du Flambeau Reservation, Wisconsin. Data were collected using a fiber-optic distributed temperature sensor (DTS) during a 5 day period from July 27 to August 1, 2016. Established procedures were followed to estimate lakebed temperatures from the raw DTS data and ca
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center
Filter Total Items: 23

Inset groundwater-flow models for the Cache and Grand Prairie Critical Groundwater Areas, northeastern Arkansas

The water resources in the Mississippi alluvial plain, located in parts of Missouri, Kentucky, Tennessee, Mississippi, Louisiana, and Arkansas, supports a multibillion-dollar agricultural industry that relies heavily on pumping of groundwater for irrigation of crops and aquaculture. The primary source of groundwater for agricultural-related pumping is the Mississippi River Valley alluvial aquifer,
Authors
Jonathan P. Traylor, Leslie L. Duncan, Andrew T. Leaf, Alec Rolland Weisser, Benjamin J. Dietsch, Moussa Guira
By
Water Resources Mission Area, Lower Mississippi-Gulf Water Science Center, Upper Midwest Water Science Center, Nebraska Water Science Center

Simulating groundwater flow in the Mississippi Alluvial Plain with a focus on the Mississippi Delta

The Mississippi Alluvial Plain has become one of the most important agricultural regions in the United States but relies heavily on groundwater for irrigation. On average, more than 12 billion gallons are withdrawn daily from the Mississippi River Valley alluvial aquifer. Declining groundwater levels, especially in the Delta region of northwest Mississippi and the Cache and Grand Prairie regions o
Authors
Andrew T. Leaf, Leslie L. Duncan, Connor J. Haugh, Randall J. Hunt, James R. Rigby
By
Upper Midwest Water Science Center

Automated construction of Streamflow-Routing networks for MODFLOW—Application in the Mississippi Embayment region

In humid regions with dense stream networks, surface water exerts a fundamental control on the water levels and flow directions of shallow groundwater. Understanding interactions between groundwater and surface water is critical for managing groundwater resources and groundwater-dependent ecosystems. Representing streams in groundwater models has historically been arduous and error prone. In recen
Authors
Andrew T. Leaf
By
Upper Midwest Water Science Center

Modflow-setup: Robust automation of groundwater model construction

In an age of both big data and increasing strain on water resources, sound management decisions often rely on numerical models. Numerical models provide a physics-based framework for assimilating and making sense of information that by itself only provides a limited description of the hydrologic system. Often, numerical models are the best option for quantifying even intuitively obvious connection
Authors
Andrew T. Leaf, Michael N. Fienen
By
Water Resources Mission Area, New York Water Science Center, Upper Midwest Water Science Center

Simulation of regional groundwater flow and groundwater/lake interactions in the Central Sands, Wisconsin

A multiscale, multiprocess modeling approach was applied to the Wisconsin Central Sands region in central Wisconsin to quantify the connections between the groundwater system, land use, and lake levels in three seepage lakes in Waushara County, Wisconsin: Long and Plainfield (The Plainfield Tunnel Channel Lakes), and Pleasant Lakes. A regional groundwater-flow model, the Newton Raphson formulation
Authors
Michael N. Fienen, Megan J. Haserodt, Andrew T. Leaf, Stephen M. Westenbroek
By
Upper Midwest Water Science Center

Flopy: The Python interface for MODFLOW

No abstract available.
Authors
Andrew T. Leaf, Michael N. Fienen
By
Water Resources Mission Area, New York Water Science Center, Upper Midwest Water Science Center

Areas contributing recharge to priority wells in valley-fill aquifers in the Neversink River and Rondout Creek drainage basins, New York

In southeastern New York, the villages of Ellenville, Wurtsboro, Woodridge, the hamlet of Mountain Dale, and surrounding communities in the Neversink River and Rondout Creek drainage basins rely on wells that pump groundwater from valley-fill glacial aquifers for public water supply. Glacial aquifers are vulnerable to contamination because they are highly permeable and have a shallow depth to wate
Authors
Nicholas Corson-Dosch, Michael N. Fienen, Jason S. Finkelstein, Andrew T. Leaf, Jeremy T. White, Joshua C. Woda, John H. Williams
By
Water Resources Mission Area, New York Water Science Center, Upper Midwest Water Science Center

Hydrogeology and simulation of groundwater flow in Columbia County, Wisconsin

This report describes the regional hydrogeology and groundwater resources of Columbia County, Wisconsin, and documents a regional groundwater flow model developed for the county. Regional hydrostratigraphic units include the unlithified aquifer, the upper bedrock aquifer, and the Elk Mound aquifer. The unlithified aquifer consists of deposits that range in composition from sand and gravel outwash
Authors
Madeline Gotkowitz, Andrew T. Leaf, Steven M. Sellwood
By
Upper Midwest Water Science Center

Risk-based wellhead protection decision support: A repeatable workflow approach

Environmental water management often benefits from a risk-based approach where information on the area of interest is characterized, assembled, and incorporated into a decision model considering uncertainty. This includes prior information from literature, field measurements, professional interpretation, and data assimilation resulting in a decision tool with a posterior uncertainty assessment acc
Authors
Michael N. Fienen, Nicholas Corson-Dosch, Jeremy T. White, Andrew T. Leaf, Randall J. Hunt
By
Water Resources Mission Area, New York Water Science Center, Oregon Water Science Center, Upper Midwest Water Science Center

Appendix C: Central sands lakes study technical report: Modeling documentation

This report provides the necessary documentation of the numerical models developed for the Central Sands Lake study in central Wisconsin and will be included as a technical appendix in the report to the Wisconsin State Legislature by the Wisconsin Department of Natural Resources (WDNR) in response to 2017 Wisconsin Act 10. This legislation directed WDNR to determine whether existing and potential
Authors
Michael N. Fienen, Megan J. Haserodt, Andrew T. Leaf, Stephen, M. Westenbroek
By
Upper Midwest Water Science Center

Risk-based decision-support groundwater modeling for the lower San Antonio River Basin, Texas, USA

A numerical surface-water/groundwater model was developed for the lower San Antonio River Basin to evaluate the responses of low base flows and groundwater levels within the basin under conditions of reduced recharge and increased groundwater withdrawals. Batch data assimilation through history matching used a simulation of historical conditions (2006-2013); this process included history-matching
Authors
Linzy K. Foster, Jeremy T. White, Andrew T. Leaf, Natalie A. Houston, Aarin Teague
By
Oklahoma-Texas Water Science Center

SFRmaker and Linesink-Maker: Rapid construction of streamflow routing networks from hydrography data

Groundwater models have evolved to encompass more aspects of the water cycle, but the incorporation of realistic boundary conditions representing surface water remains time-consuming and error-prone. We present two Python packages that robustly automate this process using readily available hydrography data as the primary input. SFRmaker creates input for the MODFLOW SFR package, while Linesink-mak
Authors
Andrew T. Leaf, Michael N. Fienen, Howard W. Reeves
By
Water Resources Mission Area, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, New York Water Science Center

Non-USGS Publications**

Leaf, A. T., Hart, D. J. and Bahr, J. M. (2012), Active Thermal Tracer Tests for Improved Hydrostratigraphic Characterization. Ground Water, 50: 726–735. doi:10.1111/j.1745-6584.2012.00913.x
Leaf, A.T., 2010. Distributed temperature sensing in the sandstone aquifer system of Wisconsin: New possibilities for characterizing hydraulic heterogeneity. M.S. Thesis, University of Wisconsin-Madison.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Mississippi Alluvial Plain (MAP) Regional Water Availability Study

The Mississippi Alluvial Plain (MAP) has become one of the most important agricultural regions in the US, and it relies heavily on a groundwater system that is poorly understood and shows signs of substantial change.

By
Lower Mississippi-Gulf Water Science Center

Python for Hydrology Self Study Curriculum

This repository contains study materials for python programming for hydrologic applications and a focus on groundwater modeling with flopy. The materials are used in an in-person curriculum at the USGS and provided here for reference for the larger hydrologic community.
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Science and Products

Surface Water and Groundwater Hydrology and Temperature, Beaver Creek, Kenai Peninsula, Alaska, 2022-2023

This data release contains measurements from continuous monitors of stream temperature, groundwater temperature, and well water levels, and discrete measurements of discharge and stream shading.
By
Alaska Science Center

MODFLOW 6 models for simulating groundwater flow in the Mississippi Embayment with a focus on the Mississippi Delta

This model archive contains the model files for the MERAS 3 and Mississippi Delta groundwater flow models documented in the U.S. Geological Survey Scientific Investigations Report 2023-5100. The MERAS 3 model provides a simplified representation of groundwater flow in the Mississippi Embayment Regional Aquifer Study (MERAS) area for the period of 1900 through 2018, with the primary goal of providi
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Columbia County Groundwater Model

A MODFLOW-NWT model was used to simulate long-term, average conditions in the regional, Columbia County groundwater system since about 1970. A GFLOW model was used to estimate regional boundary fluxes to the MODFLOW-NWT model domain.
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Distributed lakebed temperature data, Haskell Lake, Wisconsin, July 28 - Aug 1, 2016

This data release consists of lakebed temperature data collected at the sediment-water interface at the north end of Haskell Lake, Lac du Flambeau Reservation, Wisconsin. Data were collected using a fiber-optic distributed temperature sensor (DTS) during a 5 day period from July 27 to August 1, 2016. Established procedures were followed to estimate lakebed temperatures from the raw DTS data and ca
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center
Filter Total Items: 23

Inset groundwater-flow models for the Cache and Grand Prairie Critical Groundwater Areas, northeastern Arkansas

The water resources in the Mississippi alluvial plain, located in parts of Missouri, Kentucky, Tennessee, Mississippi, Louisiana, and Arkansas, supports a multibillion-dollar agricultural industry that relies heavily on pumping of groundwater for irrigation of crops and aquaculture. The primary source of groundwater for agricultural-related pumping is the Mississippi River Valley alluvial aquifer,
Authors
Jonathan P. Traylor, Leslie L. Duncan, Andrew T. Leaf, Alec Rolland Weisser, Benjamin J. Dietsch, Moussa Guira
By
Water Resources Mission Area, Lower Mississippi-Gulf Water Science Center, Upper Midwest Water Science Center, Nebraska Water Science Center

Simulating groundwater flow in the Mississippi Alluvial Plain with a focus on the Mississippi Delta

The Mississippi Alluvial Plain has become one of the most important agricultural regions in the United States but relies heavily on groundwater for irrigation. On average, more than 12 billion gallons are withdrawn daily from the Mississippi River Valley alluvial aquifer. Declining groundwater levels, especially in the Delta region of northwest Mississippi and the Cache and Grand Prairie regions o
Authors
Andrew T. Leaf, Leslie L. Duncan, Connor J. Haugh, Randall J. Hunt, James R. Rigby
By
Upper Midwest Water Science Center

Automated construction of Streamflow-Routing networks for MODFLOW—Application in the Mississippi Embayment region

In humid regions with dense stream networks, surface water exerts a fundamental control on the water levels and flow directions of shallow groundwater. Understanding interactions between groundwater and surface water is critical for managing groundwater resources and groundwater-dependent ecosystems. Representing streams in groundwater models has historically been arduous and error prone. In recen
Authors
Andrew T. Leaf
By
Upper Midwest Water Science Center

Modflow-setup: Robust automation of groundwater model construction

In an age of both big data and increasing strain on water resources, sound management decisions often rely on numerical models. Numerical models provide a physics-based framework for assimilating and making sense of information that by itself only provides a limited description of the hydrologic system. Often, numerical models are the best option for quantifying even intuitively obvious connection
Authors
Andrew T. Leaf, Michael N. Fienen
By
Water Resources Mission Area, New York Water Science Center, Upper Midwest Water Science Center

Simulation of regional groundwater flow and groundwater/lake interactions in the Central Sands, Wisconsin

A multiscale, multiprocess modeling approach was applied to the Wisconsin Central Sands region in central Wisconsin to quantify the connections between the groundwater system, land use, and lake levels in three seepage lakes in Waushara County, Wisconsin: Long and Plainfield (The Plainfield Tunnel Channel Lakes), and Pleasant Lakes. A regional groundwater-flow model, the Newton Raphson formulation
Authors
Michael N. Fienen, Megan J. Haserodt, Andrew T. Leaf, Stephen M. Westenbroek
By
Upper Midwest Water Science Center

Flopy: The Python interface for MODFLOW

No abstract available.
Authors
Andrew T. Leaf, Michael N. Fienen
By
Water Resources Mission Area, New York Water Science Center, Upper Midwest Water Science Center

Areas contributing recharge to priority wells in valley-fill aquifers in the Neversink River and Rondout Creek drainage basins, New York

In southeastern New York, the villages of Ellenville, Wurtsboro, Woodridge, the hamlet of Mountain Dale, and surrounding communities in the Neversink River and Rondout Creek drainage basins rely on wells that pump groundwater from valley-fill glacial aquifers for public water supply. Glacial aquifers are vulnerable to contamination because they are highly permeable and have a shallow depth to wate
Authors
Nicholas Corson-Dosch, Michael N. Fienen, Jason S. Finkelstein, Andrew T. Leaf, Jeremy T. White, Joshua C. Woda, John H. Williams
By
Water Resources Mission Area, New York Water Science Center, Upper Midwest Water Science Center

Hydrogeology and simulation of groundwater flow in Columbia County, Wisconsin

This report describes the regional hydrogeology and groundwater resources of Columbia County, Wisconsin, and documents a regional groundwater flow model developed for the county. Regional hydrostratigraphic units include the unlithified aquifer, the upper bedrock aquifer, and the Elk Mound aquifer. The unlithified aquifer consists of deposits that range in composition from sand and gravel outwash
Authors
Madeline Gotkowitz, Andrew T. Leaf, Steven M. Sellwood
By
Upper Midwest Water Science Center

Risk-based wellhead protection decision support: A repeatable workflow approach

Environmental water management often benefits from a risk-based approach where information on the area of interest is characterized, assembled, and incorporated into a decision model considering uncertainty. This includes prior information from literature, field measurements, professional interpretation, and data assimilation resulting in a decision tool with a posterior uncertainty assessment acc
Authors
Michael N. Fienen, Nicholas Corson-Dosch, Jeremy T. White, Andrew T. Leaf, Randall J. Hunt
By
Water Resources Mission Area, New York Water Science Center, Oregon Water Science Center, Upper Midwest Water Science Center

Appendix C: Central sands lakes study technical report: Modeling documentation

This report provides the necessary documentation of the numerical models developed for the Central Sands Lake study in central Wisconsin and will be included as a technical appendix in the report to the Wisconsin State Legislature by the Wisconsin Department of Natural Resources (WDNR) in response to 2017 Wisconsin Act 10. This legislation directed WDNR to determine whether existing and potential
Authors
Michael N. Fienen, Megan J. Haserodt, Andrew T. Leaf, Stephen, M. Westenbroek
By
Upper Midwest Water Science Center

Risk-based decision-support groundwater modeling for the lower San Antonio River Basin, Texas, USA

A numerical surface-water/groundwater model was developed for the lower San Antonio River Basin to evaluate the responses of low base flows and groundwater levels within the basin under conditions of reduced recharge and increased groundwater withdrawals. Batch data assimilation through history matching used a simulation of historical conditions (2006-2013); this process included history-matching
Authors
Linzy K. Foster, Jeremy T. White, Andrew T. Leaf, Natalie A. Houston, Aarin Teague
By
Oklahoma-Texas Water Science Center

SFRmaker and Linesink-Maker: Rapid construction of streamflow routing networks from hydrography data

Groundwater models have evolved to encompass more aspects of the water cycle, but the incorporation of realistic boundary conditions representing surface water remains time-consuming and error-prone. We present two Python packages that robustly automate this process using readily available hydrography data as the primary input. SFRmaker creates input for the MODFLOW SFR package, while Linesink-mak
Authors
Andrew T. Leaf, Michael N. Fienen, Howard W. Reeves
By
Water Resources Mission Area, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, New York Water Science Center

Non-USGS Publications**

Leaf, A. T., Hart, D. J. and Bahr, J. M. (2012), Active Thermal Tracer Tests for Improved Hydrostratigraphic Characterization. Ground Water, 50: 726–735. doi:10.1111/j.1745-6584.2012.00913.x
Leaf, A.T., 2010. Distributed temperature sensing in the sandstone aquifer system of Wisconsin: New possibilities for characterizing hydraulic heterogeneity. M.S. Thesis, University of Wisconsin-Madison.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Mississippi Alluvial Plain (MAP) Regional Water Availability Study

The Mississippi Alluvial Plain (MAP) has become one of the most important agricultural regions in the US, and it relies heavily on a groundwater system that is poorly understood and shows signs of substantial change.

By
Lower Mississippi-Gulf Water Science Center

Python for Hydrology Self Study Curriculum

This repository contains study materials for python programming for hydrologic applications and a focus on groundwater modeling with flopy. The materials are used in an in-person curriculum at the USGS and provided here for reference for the larger hydrologic community.
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center
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