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• 1. [Article] Application of Mathematical Modeling and Computer Simulation for Solving Water Quality Problems

  Deteriorated water resources in Central and Eastern Europe call for actions that should be undertaken to improve current conditions and to protect human and environmental health. Mathematical modeling ...

  Citation × Citation Citation Abstract Copy Title: Application of Mathematical Modeling and Computer Simulation for Solving Water Quality Problems Author: Makinia, Jacek, Wells, Scott A., Crawford, David, Kulbik, Marian Year: 1998 Deteriorated water resources in Central and Eastern Europe call for actions that should be undertaken to improve current conditions and to protect human and environmental health. Mathematical modeling and computer simulation is often an integral part of the decision-making process. Models and simulations allow rapid and varied evaluation of causes and effects and the principal advantage is that they enable an analysis of even long-term actions with limited investment costs. This paper provides an overview of popular models used for simulation of major elements of a water quality system: surface water quality (QUAL2E), wastewater treatment (Activated Sludge Model No.1), sewer network (SWMM), and water distribution network (EPANET). Model uses are illustrated by specific examples both in the U.S. or in Central and Eastern Europe. Title: Application of Mathematical Modeling and Computer Simulation for Solving Water Quality Problems Author: Makinia, Jacek, Wells, Scott A., Crawford, David, Kulbik, Marian Year: 1998 Deteriorated water resources in Central and Eastern Europe call for actions that should be undertaken to improve current conditions and to protect human and environmental health. Mathematical modeling and computer simulation is often an integral part of the decision-making process. Models and simulations allow rapid and varied evaluation of causes and effects and the principal advantage is that they enable an analysis of even long-term actions with limited investment costs. This paper provides an overview of popular models used for simulation of major elements of a water quality system: surface water quality (QUAL2E), wastewater treatment (Activated Sludge Model No.1), sewer network (SWMM), and water distribution network (EPANET). Model uses are illustrated by specific examples both in the U.S. or in Central and Eastern Europe. Close

• 2. [Article] CE-QUAL-W2, Version 3

  CE-QUAL-W2 is a two-dimensional water quality and hydrodynamic code supported by the U.S. Army Engineer Research and Development Center (Cole and Buchak 1995). The model has been widely applied to stratified ...

  Citation × Citation Citation Abstract Copy Title: CE-QUAL-W2, Version 3 Author: Wells, Scott A., Cole, Thomas M. Year: 2000 CE-QUAL-W2 is a two-dimensional water quality and hydrodynamic code supported by the U.S. Army Engineer Research and Development Center (Cole and Buchak 1995). The model has been widely applied to stratified surface water systems such as lakes, reservoirs, and estuaries and computes water levels, horizontal and vertical velocities, temperature, and 21 other water quality parameters (such as dissolved oxygen, nutrients, organic matter, algae, pH, the carbonate cycle, bacteria, and dissolved and suspended solids). A typical model grid is shown in Figure 1 where the vertical axis is aligned with gravity. This technical note documents the development of CE-QUAL-W2, Version 3, which incorporates sloping riverine sections. Version 3 has the capability of modeling entire river basins with rivers and interconnected lakes, reservoirs, and/or estuaries. Four example applications illustrate the use of Version 3. Title: CE-QUAL-W2, Version 3 Author: Wells, Scott A., Cole, Thomas M. Year: 2000 CE-QUAL-W2 is a two-dimensional water quality and hydrodynamic code supported by the U.S. Army Engineer Research and Development Center (Cole and Buchak 1995). The model has been widely applied to stratified surface water systems such as lakes, reservoirs, and estuaries and computes water levels, horizontal and vertical velocities, temperature, and 21 other water quality parameters (such as dissolved oxygen, nutrients, organic matter, algae, pH, the carbonate cycle, bacteria, and dissolved and suspended solids). A typical model grid is shown in Figure 1 where the vertical axis is aligned with gravity. This technical note documents the development of CE-QUAL-W2, Version 3, which incorporates sloping riverine sections. Version 3 has the capability of modeling entire river basins with rivers and interconnected lakes, reservoirs, and/or estuaries. Four example applications illustrate the use of Version 3. Close

• 3. [Article] Validation of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model

  CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lakereservoir flow, is a development product ...

  Citation × Citation Citation Abstract Copy Title: Validation of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model Author: Wells, Scott A. Year: 2002 CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lakereservoir flow, is a development product of the Waterways Experiment Station in Vicksburg, MS, USA. With the development and release of any revised or reformulated model codes, significant model validation is required. This includes comparison of model results to simple analytical solutions for hydrodynamics and water quality transport, as well as comparison to laboratory and field data. In this paper, the model is compared to numerous analytical solutions for mass transport (1-D advective mass transport) and hydrodynamics (impulsive wind stress on water surface, seiching). Suggestions are presented for proper validation protocols for hydrodynamic and water quality models. Title: Validation of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model Author: Wells, Scott A. Year: 2002 CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lakereservoir flow, is a development product of the Waterways Experiment Station in Vicksburg, MS, USA. With the development and release of any revised or reformulated model codes, significant model validation is required. This includes comparison of model results to simple analytical solutions for hydrodynamics and water quality transport, as well as comparison to laboratory and field data. In this paper, the model is compared to numerous analytical solutions for mass transport (1-D advective mass transport) and hydrodynamics (impulsive wind stress on water surface, seiching). Suggestions are presented for proper validation protocols for hydrodynamic and water quality models. Close

• 4. [Article] Basis of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model

  CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lake-reservoir flow, is a development product ...

  Citation × Citation Citation Abstract Copy Title: Basis of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model Author: Wells, Scott A. Year: 2002 CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lake-reservoir flow, is a development product of the Waterways Experiment Station in Vicksburg, MS, USA. With the development and release of any revised or reformulated model codes, significant model validation is required. This includes comparison of model results to simple analytical solutions for hydrodynamics and water quality transport, as well as comparison to laboratory and field data. In this paper, the model is compared to numerous analytical solutions for mass transport (1- D advective mass transport) and hydrodynamics (impulsive wind stress on water surface, seiching). Suggestions are presented for proper validation protocols for hydrodynamic and water quality models. Title: Basis of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model Author: Wells, Scott A. Year: 2002 CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lake-reservoir flow, is a development product of the Waterways Experiment Station in Vicksburg, MS, USA. With the development and release of any revised or reformulated model codes, significant model validation is required. This includes comparison of model results to simple analytical solutions for hydrodynamics and water quality transport, as well as comparison to laboratory and field data. In this paper, the model is compared to numerous analytical solutions for mass transport (1- D advective mass transport) and hydrodynamics (impulsive wind stress on water surface, seiching). Suggestions are presented for proper validation protocols for hydrodynamic and water quality models. Close

• 5. [Article] CE-QUAL-W2 Version 3: Hydrodynamic and Water Quality River Basin Modeling

  CE-QUAL-W2 is a two-dimensional (longitudinal-vertical) water quality and hydrodynamic computer simulation model that was originally developed for deep, long, and narrow waterbodies. The current model, ...

  Citation × Citation Citation Abstract Copy Title: CE-QUAL-W2 Version 3: Hydrodynamic and Water Quality River Basin Modeling Author: Wells, Scott A. Year: 2000 CE-QUAL-W2 is a two-dimensional (longitudinal-vertical) water quality and hydrodynamic computer simulation model that was originally developed for deep, long, and narrow waterbodies. The current model, Version 2, has been used in over 200 river, reservoir/lake, and estuary applications throughout the U.S. and abroad. Version 2, though, cannot accommodate systems that have a significant sloping water surface since the vertical coordinate system is aligned with gravity and vertical accelerations are neglected. The governing equations for CE-QUAL-W2 were re-derived so that it could be applied to entire river basins including river-estuary, lake-river, and reservoir-river systems with channel slopes. This re-derivation is one of many improvements for the Version 3 code. Other improvements include improved numerical schemes, improved and additional water quality algorithms, and algorithms for addition of hydraulic structures (weirs, gates, culverts) between model segments. Test cases for this new code include a 244 km section of the Lower Snake River in Idaho and Oregon; the Bull Run River basin composed of 3 water supply reservoirs and 2 river sections with a 2.2% and a 1.4% average slope in the Oregon Cascade mountains; and the Columbia Slough system in Portland, OR, composed of 33 separate lake systems connected by hydraulic structures and a fresh-water tidal region. Title: CE-QUAL-W2 Version 3: Hydrodynamic and Water Quality River Basin Modeling Author: Wells, Scott A. Year: 2000 CE-QUAL-W2 is a two-dimensional (longitudinal-vertical) water quality and hydrodynamic computer simulation model that was originally developed for deep, long, and narrow waterbodies. The current model, Version 2, has been used in over 200 river, reservoir/lake, and estuary applications throughout the U.S. and abroad. Version 2, though, cannot accommodate systems that have a significant sloping water surface since the vertical coordinate system is aligned with gravity and vertical accelerations are neglected. The governing equations for CE-QUAL-W2 were re-derived so that it could be applied to entire river basins including river-estuary, lake-river, and reservoir-river systems with channel slopes. This re-derivation is one of many improvements for the Version 3 code. Other improvements include improved numerical schemes, improved and additional water quality algorithms, and algorithms for addition of hydraulic structures (weirs, gates, culverts) between model segments. Test cases for this new code include a 244 km section of the Lower Snake River in Idaho and Oregon; the Bull Run River basin composed of 3 water supply reservoirs and 2 river sections with a 2.2% and a 1.4% average slope in the Oregon Cascade mountains; and the Columbia Slough system in Portland, OR, composed of 33 separate lake systems connected by hydraulic structures and a fresh-water tidal region. Close

• 6. [Article] Idaho Pend Oreille River Model: Model Development and Calibration

  The objectives of this project were to: • Develop a hydrodynamic and temperature model of Pend Oreille River using CE-QUAL-W2 Version 3.2 • Calibrate the CE-QUAL-W2 model to field data collected during ...

  Citation × Citation Citation Abstract Copy Title: Idaho Pend Oreille River Model: Model Development and Calibration Author: Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2006 The objectives of this project were to: • Develop a hydrodynamic and temperature model of Pend Oreille River using CE-QUAL-W2 Version 3.2 • Calibrate the CE-QUAL-W2 model to field data collected during 2004 and 2005 using the following water quality variables: flow, water surface elevation, and velocity temperature o dissolved oxygen nutrients (NO3-N+NO2-N, NH4-N, PO4-P) algae – chlorophyll a BOD5 and dissolved organic matter and particulate organic matter compartments (both labile and refractory) for the organic matter cycling with algae periphyton The model chosen for development was CE-QUAL-W2 Version 3.2 (Cole and Wells, 2004). This is a two-dimensional unsteady hydrodynamic and water quality model that includes typical eutrophication constituents (algae, nutrients, temperature, organic matter, dissolved oxygen, pH). Portland State University’s Water Quality Research Group is a center for development of this modeling tool (see http://www.cee.pdx.edu/w2). The model simulation was run from January 1st, 2004 to September 25th, 2005. The calibration period focused on the summers during each year when water quality data were obtained. Title: Idaho Pend Oreille River Model: Model Development and Calibration Author: Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2006 The objectives of this project were to: • Develop a hydrodynamic and temperature model of Pend Oreille River using CE-QUAL-W2 Version 3.2 • Calibrate the CE-QUAL-W2 model to field data collected during 2004 and 2005 using the following water quality variables: flow, water surface elevation, and velocity temperature o dissolved oxygen nutrients (NO3-N+NO2-N, NH4-N, PO4-P) algae – chlorophyll a BOD5 and dissolved organic matter and particulate organic matter compartments (both labile and refractory) for the organic matter cycling with algae periphyton The model chosen for development was CE-QUAL-W2 Version 3.2 (Cole and Wells, 2004). This is a two-dimensional unsteady hydrodynamic and water quality model that includes typical eutrophication constituents (algae, nutrients, temperature, organic matter, dissolved oxygen, pH). Portland State University’s Water Quality Research Group is a center for development of this modeling tool (see http://www.cee.pdx.edu/w2). The model simulation was run from January 1st, 2004 to September 25th, 2005. The calibration period focused on the summers during each year when water quality data were obtained. Close

• 7. [Article] Lake Whatcom Water Quality Model

  A water quality model of Lake Whatcom, Washington was developed as part of a Total Maximum Daily Load Study for the Washington Department of Ecology. Lake Whatcom is a large natural lake which is listed ...

  Citation × Citation Citation Abstract Copy Title: Lake Whatcom Water Quality Model Author: Berger, Chris Year: 2005 A water quality model of Lake Whatcom, Washington was developed as part of a Total Maximum Daily Load Study for the Washington Department of Ecology. Lake Whatcom is a large natural lake which is listed on the 1998 Washington State 303(d) list of waterbodies which do not meet the criterion for dissolved oxygen. Located next to the city of Bellingham, it is approximately 10 miles long and has a surface area of approximately 5000 acres and a maximum depth of over 100 meters. Eutrophication processes in the lake have been accelerated in recent years perhaps by the availability of nutrients from tributary discharges to the basin. Many of these tributaries have accelerated their nutrient loading to the system as a result of development in the watershed. The lake is being modeled using the Corps of Engineer’s model CE-QUAL-W2, which is a two-dimensional, hydrodynamic and water quality model. The project is managed by the Washington Department of Ecology which plans to make recommendations for reduction and allocation of pollutant loads. The objectives of this study were then to develop a hydrodynamic and water quality model of Lake Whatcom, calibrate the model to field data collected from February 2002 through December 2003, and use the model to evaluate strategies for water quality improvement. Title: Lake Whatcom Water Quality Model Author: Berger, Chris Year: 2005 A water quality model of Lake Whatcom, Washington was developed as part of a Total Maximum Daily Load Study for the Washington Department of Ecology. Lake Whatcom is a large natural lake which is listed on the 1998 Washington State 303(d) list of waterbodies which do not meet the criterion for dissolved oxygen. Located next to the city of Bellingham, it is approximately 10 miles long and has a surface area of approximately 5000 acres and a maximum depth of over 100 meters. Eutrophication processes in the lake have been accelerated in recent years perhaps by the availability of nutrients from tributary discharges to the basin. Many of these tributaries have accelerated their nutrient loading to the system as a result of development in the watershed. The lake is being modeled using the Corps of Engineer’s model CE-QUAL-W2, which is a two-dimensional, hydrodynamic and water quality model. The project is managed by the Washington Department of Ecology which plans to make recommendations for reduction and allocation of pollutant loads. The objectives of this study were then to develop a hydrodynamic and water quality model of Lake Whatcom, calibrate the model to field data collected from February 2002 through December 2003, and use the model to evaluate strategies for water quality improvement. Close

• 8. [Article] Flow processes in the dry regime : the effect on capillary barrier performance

  Engineered capillary barriers typically consist of two layers of granular materials designed so that the contrast in sediment hydrologic properties and sloping interface retains infiltrating water in the ...

  Citation × Citation Citation Abstract Copy Title: Flow processes in the dry regime : the effect on capillary barrier performance Author: Jansik, Danielle P. Engineered capillary barriers typically consist of two layers of granular materials designed so that the contrast in sediment hydrologic properties and sloping interface retains infiltrating water in the upper layer. We report here on the results of two bench-top capillary barrier experiments, and associated modeling. These experiments were conducted to better understand the behavior of capillary barriers in particular with respect to an engineered barrier system proposed at the potential high-level nuclear waste site at Yucca Mountain, Nevada, where different engineered barriers have been under consideration throughout the site development process (Carter and Pigford 2005; Tidwell et al. 2003). We measured hydrologic parameters for both coarse materials using standard methods and found that the two materials had similar hydrologic properties despite being morphologically different (round, uniform vs. angular, non-uniform). The rounded sand provided a better functioning capillary barrier than the angular sand, but neither experiment could be characterized as a perfectly working capillary barrier. In both cases, more than 93% of the infiltrating water was successfully diverted from the lower layer, but infiltration into the underlying layer was observed in both systems. Our experimental results show that capillary barriers designed based on standard hydrologic property measurements may result in invalid prediction of the system behavior. Moreover, our numerical simulations of these experiments show that the predicted capillary barrier performance was highly sensitive to physically realistic variability in model hydrologic parameter values. Based on this work, we believe that other non-continuum processes such as vapor diffusion and film flow contribute to the observed phenomena and are important aspects to consider with respect to capillary barrier design, as well as dry vadose zone processes in general. By applying a theoretical film flow equation representative of sediment surface geometries we were able to show that infiltration into the underlying sediment layer can be dominated by water film flow, a characteristic that is typically not considered in mainstream numerical models. Title: Flow processes in the dry regime : the effect on capillary barrier performance Author: Jansik, Danielle P. Engineered capillary barriers typically consist of two layers of granular materials designed so that the contrast in sediment hydrologic properties and sloping interface retains infiltrating water in the upper layer. We report here on the results of two bench-top capillary barrier experiments, and associated modeling. These experiments were conducted to better understand the behavior of capillary barriers in particular with respect to an engineered barrier system proposed at the potential high-level nuclear waste site at Yucca Mountain, Nevada, where different engineered barriers have been under consideration throughout the site development process (Carter and Pigford 2005; Tidwell et al. 2003). We measured hydrologic parameters for both coarse materials using standard methods and found that the two materials had similar hydrologic properties despite being morphologically different (round, uniform vs. angular, non-uniform). The rounded sand provided a better functioning capillary barrier than the angular sand, but neither experiment could be characterized as a perfectly working capillary barrier. In both cases, more than 93% of the infiltrating water was successfully diverted from the lower layer, but infiltration into the underlying layer was observed in both systems. Our experimental results show that capillary barriers designed based on standard hydrologic property measurements may result in invalid prediction of the system behavior. Moreover, our numerical simulations of these experiments show that the predicted capillary barrier performance was highly sensitive to physically realistic variability in model hydrologic parameter values. Based on this work, we believe that other non-continuum processes such as vapor diffusion and film flow contribute to the observed phenomena and are important aspects to consider with respect to capillary barrier design, as well as dry vadose zone processes in general. By applying a theoretical film flow equation representative of sediment surface geometries we were able to show that infiltration into the underlying sediment layer can be dominated by water film flow, a characteristic that is typically not considered in mainstream numerical models. Close