Cs382
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This page documents the work of CS382 - Scientific Computing, Fall 2007
Using the 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
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.
- 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.
- 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.
Plume Tracking - Bryan and Brad
Setup
- physical simulator setup approximately 16 inches away and perpendicular to the line of sight of a web enabled camera.
- A script was used to capture output of the output of the camera from the server at a rate of one every two seconds. A faster rate may be possible, but the current script did not have time to get the image and rename it within a 1 second interval.
Procedure
- set pump flow rate at maximum and allow water table to equalize
- start image capture script
- inject a full pipette bulb into well number 1
- remove pipette before allowing bulb to reinflate
- allow simulator to run for approximately 5 minutes or until the majority of the dye in the system has been discharged
- stop image capture script
We did three complete runs, each with a different dye colors. We used blue, purple and green because we thought they would give the most contrast for edge detection.
