For Teachers: Information about Legacy Cycle B, Water-Earth Dynamics

Challenge 1: The Geomorphology of Texas

The Llano Estacado is a region in the southwestern United States that encompasses parts of eastern New Mexico and northwestern Texas, including the South Plains and parts of the Texas Panhandle.  It is a mesa, an elevated tableland composed of stacked rock layers with a flat top that slopes eastward, which has been dissected by stream erosion.  The surface of the Llano Estacado in the Panhandle of Texas is a hard caliche layer called the Caprock, which lies at the top of the Ogallala Group, sandy sediments that comprise the Ogallala Aquifer.  The Caprock was formed as calcium-saturated water evaporated from these sediments near the surface, leaving behind a layer of calcite cement.  The Ogallala Aquifer, one of the largest aquifer systems in the world, is the region's groundwater resource.

The Llano Estacado terrain began developing about 70 million years ago with the uplift of the Rocky Mountains.  Rivers, such as the Pecos and Canadian, cut deep courses into the elevated rock layers.  Other rivers, including the Red, Brazos, and Colorado, flow to the east, carving channels such as the impressive Palo Duro Canyon, which was cut by the Prairie Dog Town Fork branch of the Red River.  The Llano Estacado is also characterized by arroyos and shallow gullies, known as draws, often without external drainage, as well as playas and alluvial fans.

Earth has experienced four major periods of glaciation.  The current ice age, known as the Quaternary glaciation (or Pleistocene glaciation), began about 2.58 million years ago and continues to the present.  The Quaternary ice age is characterized by cold glacial periods when large ice sheets advanced to cover much of North America, and warmer interglacial periods when the ice sheets retreated.  As the ice sheets advanced and retreated during glacial/interglacial periods, they eroded and deposited Earth material.  We are currently in an interglacial period, which started about 10,000 years ago.  The Last Glacial Maximum (LGM) occurred about 20,000 years before present (BP) and marks the time of the maximum extent of the ice sheets of the most recent glacial period.  As the ice sheets retreated after the LGM, huge volumes of meltwater poured across the landscape, modifying climate, changing river courses, creating lakes where none had previously existed, eroding the landscape, and leaving behind fluvial deposits.  These changes influenced the distribution of flora and fauna, including the migratory patterns of megafauna such as mastodon and bison, and affected the distribution and development of Paleoindian populations.  During the Holocene epoch, the Llano Estacado was home to Paleoindian groups who lived in the area when it was wetter than it is today.

Enduring Understandings

  • Landscapes result from the dynamic interplay between processes that form and uplift new crust and processes that destroy and depress the crust.  This interplay is affected by gravity, density differences, plate tectonics, climate, water, the actions of living organisms, and the resistance of Earth materials to weathering and erosion (Earth Science Literary Principle 4.7).
  • Weathered and unstable rock materials erode from some parts of Earth’s surface and are deposited in others.  Under the influence of gravity, rocks fall downhill.  Water, ice, and air carry eroded sediments to lower elevations, and ultimately to the ocean (Earth Science Literary Principle 4.8).
  • Water shapes landscapes.  Flowing water in streams strongly shapes the land surface through weathering, erosion, transport, and deposition.  Water participates in both the dissolution and formation of Earth’s materials (Earth Science Literary Principle 5.6).
  • Earth is our home; its resources mold civilizations, drive human exploration, and inspire human endeavors that include art, literature, and science.  We depend upon Earth for sustenance, comfort, places to live and play, and spiritual inspiration (Earth Science Literary Principle 7.1).
  • Geology affects the distribution and development of human populations.  Human populations have historically concentrated at sites that are geologically advantageous to commerce, food production, and other aspects of civilization (Earth Science Literary Principle 7.2).

Essential questions for students to answer in order to address the Enduring Understandings are listed in the “Generate Ideas” section.

References and Resources

  1. Andrews, K., Bohls-Graham, C. E., Let's get mapable, mapable — A legacy cycle map unit, accessed October 2016.
  2. Holliday, V. T., 1997, Paleoindian geoarchaeology of the southern high plains: Austin, University of Texas Press.  This book is a good resource for information on Paleoindian settlements on the Llano Estacado.
  3. Krech, S., Paleoindians and the great Pleistocene die-off: Encyclopedia of Earth, accessed October 2016.
  4. Llano Estacado: Wikipedia, accessed October 2016.
  5. NASA Earth Observatory Maps, accessed October 2016.
  6. Palo Duro Canyon State Park, accessed October 2016.
  7. Palo Duro Canyon: Wikipedia, accessed October 2016.
  8. Perttula, T. K., eds., 2004, The prehistory of Texas, 1st ed.: College Station, Texas, Texas A&M University Press.  This book provides a recent and thorough review of prehistoric humans in Texas.  Much of it is available as a free online preview through Google books.
  9. Texas Beyond History, The University of Texas at Austin, accessed October 2016.
  10. Timeline of glaciation: Wikipedia, accessed October 2016.
  11. University of California, San Diego, Chronology of Southwestern Archaeology, accessed October 2016.
  12. U.S. Geological Survey, Science for a changing world, Earth's Water: Water Science School, accessed October 2016.

Suggested Rubric.  Teachers may develop their own rubrics, using this one as a guide.

  • Highly Proficient.  Sophisticated, innovative, comprehensive, and accurate; contains all required products; addresses the enduring questions in an insightful, illuminating, creative manner; demonstrates sensitivity, maturity, and respect for cultural elements.
  • Capable.  Systematic, skilled, and accurate; contains all required products; addresses the enduring questions in a thoughtful, considered, and mature manner and demonstrates a thorough understanding of the concepts.
  • Adequate.  Adequate and clear; contains all required products; acceptable treatment of the enduring questions but without a thorough understanding of the concepts; lacks perspective and sensitivity.
  • Limited.  Developed, but incomplete; unreflective; contains inaccuracies and misconceptions; limited success in addressing the enduring questions; limited understanding of the concepts.
  • Inadequate.  Naïve and superficial; incomplete; contains inaccurate material; simplistic, uncritical attempt to address the enduring questions; poor understanding of the concepts; immature treatment of cultural elements.
Challenge 1 “Go Public” ProductsHighly ProficientCapableAdequateLimitedInadequate
 25 points20 points15 points10 points5 points
(1) Series of maps of topography, geology, and water resources of Texas Panhandle. (25 points)          
(2) Slide show of the evolution of the landscape since the Last Glacial Maximum, showing how the changing landscape and availability of water influences human habitation. (25 points)          
(3) Map with locations of where to look for evidence of Paleoindian habitation. (25 points)          
(4) Report that demonstrates how water shapes landscapes, drives human exploration, and affects the distribution and development of human populations. (25 points)          
SCORE          

Challenge 2: Know Your Watershed

A watershed, or drainage basin, collects water from rain and snowmelt and funnels it downslope into waterways such as streams, which in turn convey the water to larger rivers, lakes, playas, wetlands, estuaries, or the ocean.  We all live in a watershed.  Watersheds are the places we call home, where we go to school or work, and where we play.

Healthy watersheds are vital for a healthy environment and economy.  Our watersheds provide water for drinking, irrigation, and industry.  Many people also enjoy lakes and streams for their beauty, and for boating, fishing, and swimming.  Wildlife also needs healthy watersheds for food and shelter.

Enduring Understandings

  • A watershed is an area of land that drains all the streams and rainfall to a common outlet such as the outflow of a reservoir, mouth of a bay, or any point along a stream channel.
  • A watershed collects precipitation; however, not all precipitation that falls in a watershed flows out.
  • As water flows downslope under the influence of gravity, it erodes the landscape and transports sediment and dissolved materials to lower elevations.  These materials may be carried into streams, lakes, playas, wetlands, estuaries, groundwater aquifers, and ultimately to the ocean.
  • Water shapes the Earth’s surface, creating terrain (relief).  Terrain in turn affects surfacewater flow and distribution.
  • Watersheds provide water for drinking, irrigation, and industry.  Many people enjoy lakes and streams for their beauty, boating, fishing, and swimming.  Wildlife requires healthy watersheds.
  • Healthy watersheds are vital for a healthy environment and economy.

Essential questions for students to answer in order to address the Enduring Understandings are listed in the “Generate Ideas” section.

References and Resources

  1. Canadian Wildlife Federation’s Rivers to Oceans: Surface water webisode, summarizes the current threats to North America’s surface waters.
  2. Drought: EarthLabs for Educators.
  3. Nodvin, S.C., (lead author), Bledzki, L.A., (topic editor), 2008, updated 2014,Watershed, in Cleveland, C.J., eds., Encyclopedia of Earth: Washington, D.C. Environmental Information Coalition, National Council for Science and the Environment.
  4. Pidwirny, M., and Hussein, G.H.G., (lead authors), Tollner, E., (topic editor), 2007,Drainage basin, in Cleveland, C.J., eds., Encyclopedia of Earth: Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment, accessed June 29, 2009.
  5. Pidwirny, M., (lead author), Draggan, S., (topic editor), 2006, updated 2011,Surface runoff of water, in Cleveland, C.J., eds., Encyclopedia of Earth: Washington, D.C. Environmental Information Coalition, National Council for Science and the Environment, accessed October 2015.
  6. Savina, M., Floodplains in the field: Starting Point — Teaching Entry Level Geoscience and Floodplains in the field.
  7. U.S. Geological Survey, Earth's water: Water Science School.
  8. Welch, B., Stream gages and GIS: Starting Point — Teaching Entry Level Geoscience.
  9. White, I., (lead author), Hussein, G.H.G., (topic editor), 2007, updated 2012Surface water management, in Cleveland, C.J., eds., Encyclopedia of Earth: Washington, D.C., Environmental Information Coalition, National Council for Science and the Environment, October 2015.
  10. Woltemade, C.J., and Stanitsky-Martin, D., Comparing rain-gauge data with radar-derived precipitation estimates: Starting Point — Teaching Entry Level Geoscience, accessed October 2016.

Additional Resources

The Texas Water Development Board’s Raising Your Water IQ curriculum also has a lab activity to create a simple model of a watershed system entitled What is a Watershed?  The activity is on page 1-1.  However, this curriculum is geared toward middle school students.

  • Comparing Rain-Gauge Data with Radar-Derived Precipitation Estimates is an activity developed by Christopher J. Woltemade and Diane Stanitsky-Martin found in a Web site called Starting Point — Teaching Entry Level Geoscience. In this activity student teams will collect rain-gauge data and compare it with radar-derived (NEXRAD) precipitation estimates.  Next, they use GIS to look for discrepancies between the two datasets and explain them by looking for sources of error in the method.  The project culminates in a presentation to the class. The project has since expanded to include units dealing with local hydrology.

Suggested Rubric. Teachers may develop their own rubrics, using this one as a guide.

  • Highly Proficient.  Sophisticated, innovative, comprehensive, and accurate; contains all required products; addresses the enduring questions in an insightful, illuminating, creative manner; demonstrates sensitivity, maturity, and respect for cultural elements.
  • Capable.  Systematic, skilled, and accurate; contains all required products; addresses the enduring questions in a thoughtful, considered, and mature manner and demonstrates a thorough understanding of the concepts.
  • Adequate.  Adequate and clear; contains all required products; acceptable treatment of the enduring questions but without a thorough understanding of the concepts; lacks perspective and sensitivity.
  • Limited.  Developed, but incomplete; unreflective; contains inaccuracies and misconceptions; limited success in addressing the enduring questions; limited understanding of the concepts.
  • Inadequate.  Naïve and superficial; incomplete; contains inaccurate material; simplistic, uncritical attempt to address the enduring questions; poor understanding of the concepts; immature treatment of cultural elements.
Challenge 2 “Go Public” ProductsHighly ProficientCapableAdequateLimitedInadequate
 25 points20 points15 points10 points5 points
(1) Watershed characterization (maps and report) (25 points)          
(2) Watershed uses and timeline of changes over a selected period (25 points)          
(3) Water quality survey (graphs, plots, etc.) (25 points)          
(4) Stream hydrograph (25 points)          
SCORE          

Challenge 3: Groundwater—Knowing What We've Got Before It's Gone

Water is humanity's most important resource.  The largest source of available freshwater is groundwater, which exists within tiny pore spaces in rocks and sediments, and in larger spaces, such as fractures, within rocks.  A permeable water-bearing geologic formation underlain by a less permeable layer is known as an aquifer.  Groundwater from aquifers interacts with surface flow in rivers and streams in many different ways.  Groundwater is, and will continue to be, an important source of water for Texas.  However, contamination and overuse of our aquifers is an ongoing concern for many cities and rural areas.

There are 9 major and 21 minor aquifers in Texas that provide approximately 59 percent of the water used within the state.

The Ogallala Aquifer, one of the largest aquifers in the world, is a major aquifer for the Texas Panhandle.  In 2003, the Ogallala Aquifer supplied 82 percent of the water used for irrigation in Texas and more than 40 percent of all the water used in the state.  Water in the Ogallala Aquifer is stored in small pore spaces in the sediments that make up the Ogallala Formation.  Most recharge to the aquifer occurs when rainfall infiltrates into the ground and slowly travels down to the saturated part of the formation.  Because almost all rainfall evaporates or is used by plants, only an extremely small amount of rainfall actually recharges the aquifer.  Once in the aquifer, water flows slowly down to the southeast, following the regional decline in surface elevation toward the Gulf of Mexico.  Groundwater pumped from irrigation wells accounts for almost all of the discharge from the aquifer.  The low rate of recharge to the aquifer and the high pumping rates are slowly depleting the water stored in the aquifer.

The Edwards (Balcones Fault Zone) Aquifer is a major aquifer for the south central part of the state.  While it supplies less water than the Ogallala does, it feeds some of the state’s largest and most famous springs, and cities such as San Antonio are dependent on the aquifer for their water supplies.  Water in the Edwards (Balcones Fault Zone) Aquifer is stored in very small pore spaces in the limestone formations that make up the aquifer, and also in large voids, such as channels and caves that have been created as water flowing through the aquifer has dissolved the limestone.  Surface water from streams that cross the aquifer and rainfall provide most recharge to the aquifer.  Water can enter the aquifer directly through sinkholes and other openings.  Water moves, slowly in the small pore spaces and much more quickly through voids in the dissolved limestone, toward springs and wells, where it discharges from the aquifer.  Because of the high permeability and fast recharge rates in the aquifer, it responds quickly to droughts and storm events, and is particularly susceptible to contamination.

The differences in the hydrogeology and use of these two aquifers require water managers to take different approaches to water management.  For the Ogallala Aquifer, a primary concern is for the aquifer to continue to support irrigated agriculture in the region for as long as possible.  Therefore, most water managers in the region support a policy of limiting the depletion of the aquifer to support groundwater pumping for many decades into the future, but not forever.

The primary concerns for the Edwards (Balcones Fault Zone) Aquifer are to prevent contamination and maintain springflow, especially in areas where endangered species live.  For this aquifer, water managers support a policy that limits groundwater pumping to a rate that will not cause springs to dry up during drought.  In addition, there are rules for developing the area that recharges the aquifer that aim to minimize the risk of contamination.  Because there are endangered species that depend on the aquifer, water managers have more power to enforce management rules.

Enduring Understandings

  • Freshwater is humanity's most important natural resource.
  • Most of all freshwater is found in the pores and fractures within soil, sediment, and rock.
  • An aquifer is a permeable geologic formation in which groundwater is stored (reservoir); it is underlain by a less permeable formation.
  • Earth’s water cycles among the reservoirs of the atmosphere, streams, lakes, oceans, glaciers, groundwater, and deep interior of the planet.
  • Groundwater resources are essential for agriculture, manufacturing, energy production, and life.
  • Groundwater participates in both the dissolution and formation of Earth’s materials.  Examples are the karst solution features such as sinkholes and caves, and the stalagmites and stalactites found in caves.
  • Earth scientists and engineers find and manage groundwater resources, which are limited in supply.
  • Humans affect the quality, availability, and distribution of groundwater.  Pollution from sewage runoff, agricultural practices, and industrial processes reduce water quality.
  • In Texas, humans withdraw groundwater from the Ogalla Aquifer faster than it is replenished.

References and Resources

  1. Ashworth, J.B., and Hopkins, J., 1995, Major and minor aquifers of Texas: Texas Water Development Board Report 345.
  2. Brown, L. (lead author), Black, B., and Hussein, G.H.G. (topic editors), 2007, Aquifer depletion, in Cleveland, C.J., eds., Encyclopedia of Earth: Washington, D.C. Environmental Information Coalition, National Council for Science and the Environment, accessed June 30, 2009.
  3. Eckhardt, G., The Edwards Aquifer, accessed October 2016.
  4. Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains Aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, p. 63, accessed October 2016.
  5. Kundell, J., and Hussein, G.H.G. (topic editors), 2007, Groundwater, in Cleveland, C.J., eds., Encyclopedia of Earth: Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment, accessed June 30, 2009.
  6. Mace, R., Austin, B., Angle, E.S., and Batchelder, R., 2007, Surface water and groundwater—Together again?: Report to the State Bar of Texas 8th annual changing face of water rights in Texas, San Antonio, Texas, June 28-29, 2007.
  7. McGinley, M. (lead author), Hussein, G.H.G. (topic editor), 2008, Aquifers of Texas, in Cleveland, C.J., eds., Encyclopedia of Earth: Washington, D.C. Environmental Information Coalition, National Council for Science and the Environment, accessed June 30, 2009.
  8. McGinley, M. (lead author), Ornes, H. (topic editor), 2007, Aquifer, in Cleveland, C.J., eds., Encyclopedia of Earth: Washington, D.C. Environmental Information Coalition, National Council for Science and the Environment, accessed June 30, 2009.
  9. McGuire, V.L., 2009, Changes in water levels and storage in the High Plains Aquifer, pre-development to 2007: U.S. Geological Survey Fact Sheet 2009-3005, p. 2, accessed October 2016.
  10. Ogallala Aquifer: Wikipedia, accessed October 2016.
  11. Ryder, P.D., 1996, Groundwater atlas of the United States — Oklahoma, Texas: U.S. Geological Survey Hydrologic Investigations Atlas 730-E., accessed October 2016.
  12. Texas Water Development Board, 2017, Water for Texas.

Suggested Rubric.  Teachers may develop their own rubrics, using this one as a guide.

  • Highly Proficient.  Sophisticated, innovative, comprehensive, and accurate; contains all required products; addresses the enduring questions in an insightful, illuminating, creative manner; demonstrates sensitivity, maturity, and respect for cultural elements.
  • Capable.  Systematic, skilled, and accurate; contains all required products; addresses the enduring questions in a thoughtful, considered, and mature manner and demonstrates a thorough understanding of the concepts.
  • Adequate.  Adequate and clear; contains all required products; acceptable treatment of the enduring questions but without a thorough understanding of the concepts; lacks perspective and sensitivity.
  • Limited.  Developed, but incomplete; unreflective; contains inaccuracies and misconceptions; limited success in addressing the enduring questions; limited understanding of the concepts.
  • Inadequate.  Naïve and superficial; incomplete; contains inaccurate material; simplistic, uncritical attempt to address the enduring questions; poor understanding of the concepts; immature treatment of cultural elements.
Challenge 3 “Go Public” ProductsHighly ProficientCapableAdequateLimitedInadequate
 25 points20 points15 points10 points5 points
(1) Script: Vision, organization of content, use of examples/illustrations to make points, inclusion of dialogue when relevant (25 points)          
(2) Script: Scientific content (25 points)          
(3) Film/Video: Content, pace, use of animations/images/photography and experts, educational value (25 points)          
(4) Film: Scientific content (25 points)          
SCORE