ONE-DIMENSIONAL TRANSPORT WITH INFLOW AND STORAGE

Transcription

ONE-DIMENSIONAL TRANSPORT WITH INFLOWAND STORAGE (OTIS): A SOLUTE TRANSPORTMODEL FOR STREAMS AND RIVERSU.S. GEOLOGICAL SURVEYWater-Resources Investigations Report 98 – 4018

ONE-DIMENSIONAL TRANSPORT WITH INFLOW ANDSTORAGE (OTIS): A SOLUTE TRANSPORT MODELFOR STREAMS AND RIVERSBy Robert L. RunkelU.S. GEOLOGICAL SURVEYWater-Resources Investigations Report 98–4018Denver, Colorado1998

U.S. DEPARTMENT OF THE INTERIORBRUCE BABBITT, SecretaryU.S. GEOLOGICAL SURVEYThomas J. Casadevall, Acting DirectorThe use of trade, product, industry, or firm names is for descriptive purposes only and does not implyendorsement by the U.S. Government.For additional information write to:Copies of this report can be purchased from:District ChiefU.S. Geological SurveyBox 25046, MS 415Denver Federal CenterDenver, CO 80225U.S. Geological SurveyInformation ServicesBox 25286, MS 517Denver Federal CenterDenver, CO 80225

CONTENTSAbstract .1.0 Introduction .1.1 Model Enhancements .1.2 Report Organization .1.3 Acknowledgments .2.0 Theory .2.1 Background - Transient Storage Models .2.2 Governing Differential Equations .2.2.1 Processes Considered / Model Assumptions .2.2.2 Time-Variable Equations .2.2.3 Steady-State Equations .2.3 The Conceptual System .2.4 Numerical Solution - Time-Variable Equations .2.4.1 Finite Differences .2.4.2 The Crank-Nicolson Method .2.4.3 Main Channel Solute Concentration .2.4.4 Storage Zone and Streambed Sediment Concentrations .2.4.5 Decoupling the Main Channel, Storage Zone, and Streambed Sediment Equations .2.5 Numerical Solution - Steady-State Equations .2.6 Boundary Conditions .2.6.1 Upstream Boundary Condition .2.6.2 Downstream Boundary Condition .2.7 Parameter Estimation .3.0 User’s Guide .3.1 Applicability .3.2 Model Features .3.2.1 Simulation Modes: Time-Variable and Steady-State .3.2.2 Conservative and/or Nonconservative Solutes .3.2.3 Flow Regimes .3.2.4 Parameter Estimation using OTIS-P .3.3 Conceptual System, Revisited .3.4 Input/Output Structure .3.4.1 OTIS .3.4.2 OTIS-P .3.5 Input Format .3.5.1 Units .3.5.2 Internal Comments .3.5.3 The Control File .3.5.4 The Parameter File .3.5.5 The Flow File .3.5.6 The Data File (OTIS-P only) .3.5.7 The STARPAC Input File (OTIS-P only) .3.6 Model Execution .3.6.1 OTIS .3.6.2 OTIS-P .3.7 Output Analysis .3.7.1 The Solute and Sorption Output Files .3.7.2 The Post-Processor .3.7.3 Plotting Alternatives .4.0 Model Applications .4.1 Application 1: Conservative Transport (OTIS) 12122222424252626272729354041434444454546474848III

4.2 Application 2: Transport with Kd Sorption (OTIS) .4.3 Application 3: Transport with First-Order Decay (OTIS) .4.4 Application 4: Conservative Transport with Unsteady Flow (OTIS) .4.5 Application 5: Continuous Boundary Condition and Parameter Estimation (OTIS-P) .4.6 Application 6: Steady-State Simulation and Parameter Estimation (OTIS-P) .5.0 Software Guide .5.1 Supported Platforms .5.2 Software Distribution .5.3 Installation .5.4 Compilation .5.5 Software Overview .5.5.1 Model Development .5.5.2 Include Files .5.5.3 Error Checking .References .25.26.27.28.Transient storage mechanisms .Conceptual model that includes the main channel and the storage zone.Conceptual system subdivided into a number of discrete segments (control volumes) .Segmentation scheme used to implement the numerical solution .Upstream boundary condition defined in terms of a fixed concentration .Downstream boundary condition defined in terms of a fixed dispersive flux.Iterative parameter-estimation procedure .Conceptual system that includes one or more reaches .The first reach in the conceptual system and the required input variables .OTIS Input/Output files .OTIS-P Input/Output files.Upstream boundary condition options.Example solute output file for a time-variable simulation.Control file for Application 1 .Parameter file for Application 1.Steady flow file for Application 1.Simulated and observed chloride concentrations at 105 and 433 meters .Partial listing of the parameter file for

2 One-Dimensional Transport with Inflow and Storage (OTIS): A Solute Transport Model for Streams and Rivers 1.0 INTRODUCTION This report describes the development and use of a solute transport model incorporating One-Dimensional Transport with Inflow and Storage (OTIS). The OTIS solute transport model was originally documented by Runkel and Broshears (1991); this document