Elwha Educational Video 2: Sediment: Friend or Foe?

Duration:

7 minutes, 33 seconds

What role does sediment play in the Elwha river ecosystem? How can sediment help or hurt the river?

 

Exploring the Elwha River Ecosystem Video Series- Freeing the Elwha Curriculum Alignment

Sediment: Friend or Foe?
Freeing The Elwha Curriculum	Next Generation Science Standards Correlation
Lesson 1: Weather Patterns of the Pacific CoastTopics: Precipitation/Climatic Patterns in the Northwest, the Rainshadow Effect, Snowpack and GlaciersGuiding Question: Guiding Question: How can learning about weather patterns help us to understand our water resources?Overview: The weather in the Pacific Northwest is dependent on the Pacific Ocean. Generally speaking, weather in the region is mild, with cool wet winters, and warm dry summers with extremes in temperature and precipitation being unusual. However, despite the moderating effects of the Pacific Ocean, the mountains are very important in terms of the distribution of precipitation across the region and the development of water storage in the form of a snowpack during the summer drought. The mountain, via topographical lifting and the rainshadow effect, causes some areas to be temperate rainforests, while others become deserts.	ESS2.C: The Roles of Water in Earth’s Surface Processes The complex patterns of the changes and the movement of water in the atmosphere, determined by winds, landforms, and ocean temperatures and currents, are major determinants of local weather patterns. (MS-ESS2-5) ESS2.C: The Roles of Water in Earth’s Surface Processes Water continually cycles among land, ocean, and atmosphere via transpiration, evaporation, condensation and crystallization, and precipitation, as well as downhill flows on land.(MS-ESS2-4) ESS2.D: Weather and Climate Weather and climate are influenced by interactions involving sunlight, the ocean, the atmosphere, ice, landforms, and living things. These interactions vary with latitude, altitude, and local and regional geography, all of which can affect oceanic and atmospheric flow patterns. (MS-ESS2-6) Crosscutting Concepts: Systems and System Models, Cause and Effect, Energy and Matter
Lesson 2: What is a WatershedGuiding question: Healthy watersheds are vital for a healthy environment and economy. How can understanding watersheds and particularly the Elwha watershed help you protect the water and other natural resourcesOverview: A watershed is an area where all precipitation either drains on the surface or underground into an outlet stream or river. Watersheds can vary by scale, with a large watershed containing many smaller ones. In addition to surface waters, much of the precipitation filters through the soil and bedrock into the aquifer. Aquifers are bounded by impermeable layers and once water reaches those, they begin to flow more horizontally. Groundwater flows along the rock layers until it reaches a surface point that is below the water table. Then, the water reemerges as springs or seep that flow over the surface.	ESS2.C: The Roles of Water in Earth’s Surface Processes Water continually cycles among land, ocean, and atmosphere via transpiration, evaporation, condensation and crystallization, and precipitation, as well as downhill flows on land.(MS-ESS2-4) Crosscutting Concept: Energy and Matter
Lesson 3: River Flow and Sediment MovementGuiding Question: Seasonal weather patterns affect the flow patterns of water into the rivers (and watersheds) of western North America. What landform features can form when erosion is caused by fast -moving water from Spring and Fall rains, and snowpack melt off?Overview: The focus of this lesson is to learn about the seasonal flow patterns of rivers in western North America, and the erosional effects of fast-moving water. Rivers in the west tend to experience high flows during the spring rains and snowpack melt off, low flows during the long summer drought, increased flows during the return of the fall rains, and slightly lower flows in winter when much of the precipitation is trapped as snow. However, strong storms can result in sudden spikes of water flows and flash flooding.Fast-flowing rivers can move large stones and carry a lot of sediment, so they have the ability to pluck stones from the bedrock and can carve deep canyons. Eventually fast-flowing rivers form V-shaped valleys, with terraces/benches forming along former riverbeds. Where flows reach steep gradients, rapids and waterfalls will form. The goal of this lesson is to demonstrate the features that can form in these fast-flowing streams.	SS2.A: Earth Materials and Systems Rainfall helps to shape the land and affects the types of living things found in a region. Water, ice, wind, living organisms, and gravity break rocks, soils, and sediments into smaller particles and move them around. (4-ESS2-1) ESS2.D: Weather and Climate Scientists record patterns of the weather across different times and areas so that they can make predictions about what kind of weather might happen next. (3-ESS2-1) ESS2.A: Earth Materials and Systems All Earth processes are the result of energy flowing and matter cycling within and among the planet’s systems. This energy is derived from the sun and Earth’s hot interior. The energy that flows and matter that cycles produce chemical and physical changes in Earth’s materials and living organisms. (MS-ESS2-1) Crosscutting Concepts: Stability and Change,
Lesson 4: Sediment Deposition and River StructuresGuiding Question: As rivers age and slow they deposit sediment and form sediment structures, how are sediments and sediment structures important to the river ecosystem?Overview: The focus of this lesson is the deposition and erosional effects of slow-moving water in low gradient areas. These "mature rivers" with decreasing gradient result in the settling and deposition of sediments and the formation sediment structures. The river's fast-flowing zone, the thalweg, causes erosion of the river banks forming cliffs called cut-banks. On slower inside turns, sediment is deposited as point-bars. Where the gradient is particularly level, the river will branch into many separate channels that weave in and out, leaving gravel bar islands. Where two meanders meet, the river will straighten, leaving oxbow lakes in the former meander bends.	SS2.A: Earth Materials and Systems Rainfall helps to shape the land and affects the types of living things found in a region. Water, ice, wind, living organisms, and gravity break rocks, soils, and sediments into smaller particles and move them around. (4-ESS2-1) Crosscutting Concepts: Stability and Change,
Lesson 5: Sediment Deposition at the SeaGuiding Question: As rivers carry sediment to the sea different sediment structures are formed along shorelines, how is sediment important to both river and the shoreline ecosystems?Overview: The focus of this lesson is depositional and erosional effects as rivers meet the sea. As a river meets the sea, the sediment it carries is deposited in a fan-like formation called a delta. As longshore drift picks up and transports the sediment, it can be carried and deposited down current to form shoreline sediment features such as sand bars, spits, and barrier islands. These sediments can protect areas behind them from the effect of ocean waves to form estuaries, salt marshes, and lagoons. Features such as headlands and sea stacks can intercept and deflect the currents, allowing sediments to be deposited on beaches in sheltered coves.	SS2.A: Earth Materials and Systems Rainfall helps to shape the land and affects the types of living things found in a region. Water, ice, wind, living organisms, and gravity break rocks, soils, and sediments into smaller particles and move them around. (4-ESS2-1) Crosscutting Concepts: Stability and Change,
Lesson 6: Effects of Elha Dams on SedimentsGuiding Question: The building of the Elwha River Dams has had a huge effect on the natural sediment transport and sediment structures along the Strait of Juan de Fuca. What benefit will the removal of the dams have to natural and human communities along the Strait of Juan de Fuca as natural sediment transport resumes?Overview: The focus of this lesson is on the effects that building the Elwha River dams had on the natural sediment transport and deposition mechanisms in the Strait of Juan de Fuca. The formation of Lake Mills caused most of the sediment to deposit in a delta at the head of the reservoir, rather than at the mouth of the river. In addition to a large delta, a bed of fine silt covers the lake floor. The loss of this sediment has resulted in severe consequences downstream. Sandy beaches at the mouth of the river, which used to contain rich shellfish beds, have washed away. Salmon spawning beds in the lower five miles of the river have eroded away and sediment transport to Ediz Hook by longshore drift has stopped as well.	LS2.C: Ecosystem Dynamics, Functioning, and Resilience Ecosystems are dynamic in nature; their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations.(MS-LS2-4) Crosscutting Concepts: Energy and Matter Influence of Science, Engineering, and Technology on Society and the Natural World The uses of technologies and any limitations on their use are driven by individual or societal needs, desires, and values; by the findings of scientific research; and by differences in such factors as climate, natural resources, and economic conditions. (MS-ETS1-1) All human activity draws on natural resources and has both short and long-term consequences, positive as well as negative, for the health of people and the natural environment. (MS-ETS1-1
Lesson 16: Restoring the Elwha RiverGuiding Question: There are many important factors involved in removing the Elwha Dams and restoring the Elwha River. What strategies is Olympic National Park employing to help the river and its anadromous fish recover?Overview: This lesson focuses on the plans to remove the dams, restore the river, and return salmon to the Elwha River watershed. Managers will have to use different strategies depending on the current population levels, life histories, and habitat requirements for each species of salmon, to ensure recovery. Some species will be able to naturally recolonize the river and return to anadromy. During the dam removal process, there is expected to be great amounts of sediment released from the deltas which have formed at the mouth of the reservoirs. To assure their survival, some salmonid species will be stored and propagated in hatcheries, protected from the high levels of suspended sediment. Some species will need to be out-planted up river to facilitate recolonization following dam removal. In addition, a great deal of ecological work will be necessary post dam removal to restore vegetation, engineer logjams, and return the sediment regime to form spawning beds.	ETS1.A: Defining and Delimiting Engineering Problems The more precisely a design task’s criteria and constraints can be defined, the more likely it is that the designed solution will be successful. Specification of constraints includes consideration of scientific principles and other relevant knowledge that is likely to limit possible solutions. (MS-ETS1-1) ETS1.B: Developing Possible Solutions A solution needs to be tested, and then modified on the basis of the test results in order to improve it. (MS-ETS1-4) There are systematic processes for evaluating solutions with respect to how well they meet the criteria and constraints of a problem. (MS-ETS1-2), (MS-ETS1-3) Sometimes parts of different solutions can be combined to create a solution that is better than any of its predecessors. (MS-ETS1-3) Models of all kinds are important for testing solutions. (MS-ETS1-4) Crosscutting Concepts: Stability and Change, HYPERLINK "http://ngss.nsta.org/DisciplinaryCoreIdeas.aspx?id=40&detailid=120"