Cs382

This page documents the work of CS382 - Scientific Computing, Fall 2007

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enVision Tabletop Groundwater Simulator

General Instructions

• Setup
• Teardown and cleaning
• Packing and travelling

Instructions for Demonstrations

• First one
• Second one
• etc.

Computational Groundwater Simulations

Fitz, Bryan and Mikio

Confined aquifier simulation

Parabolic contaminant flow model

x

• Experiments
  • Demonstrating porosity
    • model water flow unconfined aquifier
  • Illustrating groundwater flow in a confined aquifer
    • We will use a cellular automata model where at the lowest level, a cell is either fresh water or contaminated. We see this problem split into two concepts - speed and direction.
      • Direction: The illustration to the right demonstrates our assumptions about how the water will move through the material. The simulation will calculate a new direction at each generation based on it's position relative to the known locations of water input and output.
      • Speed: Remains constant throughout generations for a given run. The "speed" value represents a combination of speed of water flow and material porosity, and in terms of the simulation is the possibility that a a neighboring cell in the flow direction becomes contaminated.

• • Describing recharge, transition and discharge areas
    • modeling behavior of water recharge, discharge in wells, lake, etc

• Computational Tools
  • C
    • +Very fast
    • +Libraries are available
    • +Good distributed Libraries
    • -Potentially difficult to use
    • -no graphics libraries
  • Netlogo
    • +Fancy Graphics
    • +Fun to use
    • +Available examples/code
    • -Slow
    • -Small problem size
    • -No Distributed processing

Peter and Mikio

• Experiment
  • Describing the model
    • Describing the various parts of the Groundwater Simulator by attaching tags: Key words -- wells, artesian wells, lake, underground storage tank, septic tank, springs, vegetative layer, river/ocean, recharge area, discharge area, aquifers, confining layer, clay layers
  • Illustrating and Calculating Porasity of different types of earth materials
  • Determining how it is easy for ground water to move in different earth materials.
• Computetional Tool
  • NetLogo for computatinal experiment

Brad and Nate

Our goal is an incremental approach towards illustrating groundwater contamination in a confined aquifer. The confined aquifer, viewed between wells 1 and 8, offers an environment within the groundwater simulator with the fewest variables. The first 4 experiments are an effort to illustrate the behavior and underlying science that must be understood and demonstrated in the final experiment.

• Experiments
  • Diffusion
    • Show diffusion without groundwater movement.
  • Flow Rate
    • Show the leading edge of groundwater contamination as a indicator of flow rate (related to section 5 and 13 in manual)
  • Contaminant Plume Length
    • Determine whether contaminant plume length is affected by flow rate for a given amount of dye
  • Soil Density
    • Use displacement method and measurements of aquifer component to determine the density of the soil. We can use this value in silico.
  • Illustrate laminar flow in a confined aquifer (Activity 7-1)
    • Show laminar flow between wells 1 and 8.

• Computational Tools
  • NetLogo
    • + Visualization built in
    • + Agent and cell based simulation structure built in
    • - Possible limitation on world size / agent count in RAM
    • - Possible run time slower than groundwater simulator at higher flow rates
    • - Not parallel
  • Python and MYMPI
    • + Parallelizable
    • + Faster than NetLogo in serial code ?
    • + Visualization software exists
      • TKInter - easy to install; seemingly easy to use
    • - Visualization software must be integrated
    • - MYMPI is untested
      • Need to compile stuff.

Activities in Manual

• Level I: Teaching Basic Groundwater Facts and Concepts with the Model
  • 2-1: Demonstrating porosity
  • 2-2: Porosity demonstrations
  • 3-1: Illustrating the water table (groundwater not flowing)
  • 3-2: Illustrating the water table (groundwater flowing)
  • 3-3: Raising and lowering the water table
  • 4-1: Describing recharge, transition and discharge areas
  • 5-1: Describing the slope on the water table (hydraulic gradient)
  • 6-1: Observing water level differences in wells in recharge and discharge areas
  • 6-2: Potentiometric surfaces
  • 7-1: Illustrating groundwater flow in a confined aquifer
  • 7-2: Groundwater flow in an unconfined (water table) aquifer
  • 8-1: Illustrating and describing groundwater contamination
  • 9-1: Pump and Treat, How to operate the syringe system
  • 9-2: In-situ treatment
• Level II: Using the Groundwater Model (Elementary - Middle School)
  • 10-1: Describing the model
  • 11-1: Illustrating and calculating porosity
  • 12-1: Estimating the permeability of soils
  • 12-2: Graphing the permeability of soils
  • 12-3: Determining the actual permeability (MS)
  • 12-4: Illustrating the water table
  • 12-5: Explaining the water levels in water wells
  • 12-6 Explaining a sloping water table
  • 12-7 Determine the amount of water (discharge) flowing through the model
  • 14-1: Demonstration illustrating what happens when contaminants in groundwater have densities that differ from groundwater
  • 14-2: Illustrating how water wells are contaminated
  • 14-3: Illustrating the effect of pumping wells on contaminated aquifers
  • 14-4: Illustrating how contaminant concentrations can be changed in groundwater