Groundwater Lab done

.docx

School

Laramie County Community College *

*We aren’t endorsed by this school

Course

1001

Subject

Geography

Date

Jan 9, 2024

Type

docx

Pages

7

Uploaded by ChefWillpower15868

Report
Groundwater Lab Introduction: Even though groundwater only makes up an estimated 0.61% of the water on Earth, it accounts for 98% of the available fresh water (Fetter, 1999). In many parts of the world (including southwestern North America) water is the primary limiting resource for society and the surrounding ecosystems. Despite the central role of groundwater’s importance to society, few citizens understand even the basics of groundwater flow. You need to understand the fundamentals of groundwater flow and contamination. It may save you thousands of dollars when purchasing a home, it may save your community million of dollars in clean-up costs, and it might preserve the rich biotic diversity in riparian areas. In this lab we will explore the basics of groundwater movement, the effects of pumping wells, and groundwater contamination using an online version of a groundwater model that looks rather like an ant farm. Goals and Objectives: The groundwater “ant farm” model provides a wonderful hands-on experience that allows you to observe and manipulate a miniature hydrologic system. You and your lab partners will be able to see the results of changing recharge, pumping wells, and the surface contamination. Specifically, you will: a) Observe the saturated and unsaturated zones of the aquifer in the model a) Manipulate and observe variations in recharge and discharge b) Observe, record and explain what causes groundwater to flow. c) Observe the connections between surface water and groundwater using dyes. d) Examine the effect of pumping water from a well on groundwater flow. During this lab, you will be asked to generate hypotheses about groundwater flow and then will be able to test your hypotheses using the "ant farm." You will not be graded on your hypotheses (except on whether or not you had one!). You will, however, be graded on your observations of the tests. Before you start: Watch the introductory video ( https://vimeo.com/398697315 ). v. 4/9/23
This lab uses an online version of the ant farm groundwater model, found at https://pvw.kitware.com/sandtank/ . You can explore the model on your own, using directions in the web sites manual ( https://www.hydroframe.org/sand-tank-user-manual ). At the bottom of the page, after the explanation of the various controls, you can find instructions for a basic run. Feel free to experiment with it before starting this lab. In this lab, every line with bullets (dots) gives you instructions for things to do. Every line with numbers asks questions that you need to answer to get credit for the lab. Any question that starts with "prediction" should be answered before you do the next group of instructions - you are making a hypothesis about what you think will happen. The "prediction" questions will receive full credit as long as you answer them. The "observation" questions ask about things that happen when you run the model. The "generalization" questions deal with larger concepts. Please change the font of your answers to blue and leave a line space after the question. Part 1: Groundwater flow Figure 1. Screen capture of the basic groundwater model on the hydroframe website. Click on the hydraulic head slider (the top of the blue column on the left side of the model). Raise it until the number at the bottom reads 40.00. Set the Lake/River toggle to "Lake" v. 4/9/23
Run the model by clicking the button that says "RUN" in the upper right corner of the window. 1. Observation: The top of the blue area on the model represents the water table. Which direction does the water table slope? The direction the water table slopes is from high left to high right 2. Observation: Describe the difference in height of the water level in the wells on the left side of the model versus the water level in the wells on the right side of the model. The height of the water level in the wells on the left side of the model was higher but water gradually moved to the right which had a lower level of water. It moved towards a lower energy state. 3. Observation: Layers above the water table are unsaturated. Which of the layers are unsaturated? The layers which are unsaturated are the gravel and loam horizons. These are known as the ‘vadose’ zones. 4. Observation Layers below the water table are saturated. Which of the layers are saturated? he layers below the water table that are saturated are clay, sand, gravel and loam. There is a similar composition, but different water level 5. Observation: The two dark-colored layer have a lower permeability than the rest of the layers. Permeable layers that are entirely underneath a lower permeability layer are known as "confined aquifers." In this model, which layers are confined aquifers? The layers that are the confined aquifers are the clay horizons. The clay layer at the bottom is more of a complete layer but the one above cuts off at the right side of the water table, making it incomplete and easier for water to pass through. 6. Prediction: when you run the model, which direction will the water flow? Using the red (down) arrow, inject 2 units of dye into Well D (fourth well from the left, the shallowest well). Click "run" once. You should see a large red splotch appear at the bottom of the well. v. 4/9/23
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help