Lesson 6 – Death Valley Middle Basin Case Study
Objectives
See the NGSS listed in the left-hand menu and below. When applicable, connections to 21st Century Learning Skills and other published standards are also included in the chart below. In addition, for this lesson, here is a breakdown of:
What Students Learn
- Measurements of indicator species can be used to make inferences about environmental conditions.
- Quantity and resolution of a data collection plan is limited by resources.
- Mine tailings are point sources of heavy metal pollution.
- Population density is a measurement of the number of individuals living in a given amount of space.
What Students Do
- Generate a sampling plan based on limited resources.
- Share data with other student groups.
- Refine their sampling plan based on current observations.
- Analyze data about population density of indicator species to infer locations of freshwater springs and point sources of arsenic pollution.
- Analyze their findings to propose a watershed management plan for Middle Basin in Death Valley.
- Communicate their research and their proposal in a presentation.
- Communicate their findings and respond to questions and criticisms regarding their proposals.
| Aligned Washington State Standards | |||||||||
| Washington Science Standards (Next Generation Science Standards)
Performance expectation(s): Please keep in mind that this one lesson can briefly touch upon several PEs or can dive deeply into 1-2. This also depends on the emphasis you place on certain components from the above 5 lessons. Based on which PE you emphasize, you may address different practices, core ideas and concepts to different levels. HS-PS3-3 Design, build, and refine a device that works within given constraints to convert one form of energy into another form of energy. HS-PS4-1 Use mathematical representations to support a claim regarding relationships among the frequency, wavelength, and speed of waves traveling in various media. HS-PS4-5 Communicate technical information about how some technological devices use the principles of wave behavior and wave interactions with matter to transmit and capture information and energy. HS-LS2-1 Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales; HS-LS2-2 Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales. HS-LS2-4 Use mathematical representations to support claims for the cycling of matter and flow of energy among organisms in an ecosystem. HS-LS2-6 Evaluate the claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem. HS-LS2-7 Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity. HS-LS4-3 Apply concepts of statistics and probability to support explanations that organisms with an advantageous heritable trait tend to increase in proportion to organisms lacking this trait. HS-LS4-6 Create or revise a simulation to test a solution to mitigate adverse impacts of human activity on biodiversity. HS-ESS2-2 Analyze geoscience data to make the claim that one change to Earth’s surface can create feedbacks that cause changes to other Earth systems. HS-ESS3-1 Construct an explanation based on evidence for how the availability of natural resources, occurrence of natural hazards, and changes in climate have influenced human activity. HS-ESS3-2 Evaluate competing design solutions for developing, managing, and utilizing energy and mineral resources based on cost-benefit ratios. HS-ESS3-3 Create a computational simulation to illustrate the relationships among management of natural resources, the sustainability of human populations, and biodiversity. HS-ESS3-4 Evaluate or refine a technological solution that reduces impacts of human activities on natural systems. HS-ETS1-1 Analyze a major global challenge to specify qualitative and quantitative criteria and constraints for solutions that account for societal needs and wants. HS-ETS1-2 Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering. HS-ETS1-3 Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics, as well as possible social, cultural, and environmental impacts. Three potential performance expectations that could be connected to this lesson with a slight deviation are, HS-PS1-7: Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction, HS-LS1-2. Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms and HS-ESS2-5: Plan and conduct an investigation of the properties of water and its effects on Earth materials and surface processes.
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Instructions
Death Valley Scenario: Teacher Information
This is a partially fictitious scenario set up with the following premises and caveats.
- The arsenic source is from a century-old abandoned gold mine. Exposed tailings with arsenic are leaching this toxic element down a canyon which spills onto an alluvial fan (a distinct blue color) in zoom out square H1. From there, it spreads across the alluvial fan until it enters the basin itself, where it is highly diluted. This is a POINT SOURCE. In their water management plan, students will (hopefully) include some mitigation strategies such as a dam or holding basin to contain and isolate the runoff from this alluvial fan. Show students the PowerPoint which gives examples of the repercussions of mining (Google Slides, PowerPoint).
- The freshwater source is more diffuse and located in the northeast arm of the Middle Basin where freshwater seeps into the floor of the basin. This is the deepest part of the basin, although the depth varies with precipitation and evaporation. The freshwater in-flow is crucial for keeping at least a small area below the 25% salinity level that would render the entire basin sterile. Brine shrimp and flies flourish here when salinity and temperature conditions are favorable.
- For the purposes of this scenario, it’s considered possible to take water samples at each grid location – perhaps during one of the rare precipitation events. Actually, on most days of the year, there would be no possibility of taking water samples throughout most of the valley. In fact, on any given day, a visiting scientist could find Middle Basin completely dry, for any practical purposes. For that matter, simply taking samples at some of the points in the grid is often next to impossible, given that Middle Basin is often just a vast muddy salt flat. We’re glossing over all that, aren’t we? Have students read the case study (Google Doc, Word Doc).
- The sample preparation template (Google Slide, PowerPoint) offers a loading plan, tied to the Middle Basin maps, for a 10 x 10 sample grid you can offer to your students. Notice that you can simply prepare 10 different stock solutions at different concentrations, load the requisite number of test tubes, THEN distribute them into the sample grid for students to analyze. Depending on the amount of time allotted to this entire activity, and your energy for preparing more samples, you may even consider allowing students to zoom in even closer to sample a specific area of Middle Basin.
- While the simple version of this activity involves having students analyze and map distributions (Google Slide, PowerPoint) of 2 populations of extremophile microbes, there are numerous additional pieces of the activity we urge you to emphasize and incorporate into the work. It is in these pieces that students will experience the richness of the activity, and learn to think like scientists.
- Students should have the experience of working with incomplete data. They should analyze their incomplete data at several stages, and take new additional data not based on a plan they made before they started, but based on what their first set of data tells them. Their investigation should be dynamic, changing to fit the conditions of the moment.
- Students should have the experience of sharing data with other groups and interpreting the data developed by other groups, in relation to their own data. As a teacher, you can create this type of communication at different levels, moving from meeting as a small lab group to a couple of lab groups, to summarizing the data at the end of the investigation with the entire class. Allow for this time as you plan your work flow.
- Students should have the opportunity to do something with their data. In this scenario, we’ve suggested that students should write a watershed management plan (Google Doc, Word Doc) for this part of Death Valley National Park. Depending on your students, you may wish to structure this final part as an assessment of the entire activity. You’ll want to think about how much of this “plan” you want to spell out for your students, or whether you want to leave it open-ended. A brainstorming session with your class would (hopefully) develop most of an outline for what the details of a watershed management plan might look like.
You completed Instructional Activities. Please move to Career Connections
Career Connection
Based on how much time you have available, choose a career-connected activity below. In each case, recap what your students just learned in the lesson to the activity.
| A homework/
outside of class |
B 5-10 minutes in class | C half of class period (~25 minutes) | D entire class period (~50 minutes) |
| Give handout for students to watch Amy’s video and answer questions at home as homework.
—————– Post TOWN HALL (see option D) is a great time to ask for a written evaluation of the TOWN HALL experience. Writing prompts are included in the TOWN HALL document. |
A + Brainstorm on interview questions for Amy using a whiteboard or projector.
—————– Students play (if prerecorded) or perform their finished ELEVATOR SPEECHES. |
Idea 1: Students build and present a 3 minute “ELEVATOR SPEECH”: who they are, their current interests, what they’re going to do next, and where their path might lead. Emphasis should be placed on how different future experiences support systems thinking.
—————– Idea 2: Students research roles for TOWN HALL and potentially interview one another in some round robin situations, to get and give feedback on the research they have accumulated. |
Conduct the TOWN HALL Community Meeting.
We recommend setting aside an entire class period for the meeting itself. We only recommend doing this meeting IF you’ve prepared students well ahead of time by assigning roles and encouraging research to support those roles. |
Additional Information:
- If you are having students present an elevator speech, you might consider having students interview one another in some round-robin situations, to get and give feedback and what they’re considering including in the speech.
Assessment
How will I know they know?
- Review Students Watershed Management Plan. The EPA has examples http://water.epa.gov/polwaste/nps/handbook_index.cfm
Resources
- Teacher: Advanced Prep (Google Doc, Word Doc), Loading Template for Water Samples, Key Map Grid Arsenic Resistant Organism Y (Google Doc, Word Doc), How to make color maps with “pixlr”ppt (Google Slide, Powerpoint) , Template for use with pixlr.com, Making test tube racks (Google Doc, Word Doc),
- Student: Death Valley Case-Student Reading (Google Doc, Word Doc), Color Maps Death Valley, Repercussions of Mining-ppt (Google Slides, PowerPoint), Watershed Plan directions (Google Doc, Word Doc)
- EPA examples/parameters of watershed management plans: http://water.epa.gov/polwaste/nps/handbook_index.cfm
Extension
Ideas for students (Google Doc | Word Doc) in addition/instead of making a watershed management plan.