Building Vocabulary: Defining Scientific Vocabulary
We will spend five classes building table top river models and conducting controlled experiments as outlined in River Cutters (18) from the Lawrence Hall of Science. These sessions will help the students gain an understanding of key river and river related language: aquifer, bed load, delta, dendrite, drainage basin, drainage pattern, eddy, erosion, floodplain, gully, lake, landslide, levee, meander, mouth, plunge pool, pothole, rapids, river, riverbank, riverbed, sandbar, sediment, source, spring, stream capture, tributary, valley, v-shaped valley, waterfall, watershed and water table. This is accomplished through the following sessions: exploring a table top river model, discussing river features, time and the river, dams and toxic waste, results of the river model, and age and slope. The GEMS guides produced by the Lawrence of Hall of Science at the University of California at Berkley are accurate and aligned to the National Science Standards. The experiments and language development is essential prior to the construction of a scaled model of local river systems.
The West River
The student generated mural, aerial photographs of Edgewood Park and site visits will be used to create a scale model of the West River. A 1 foot to 1 inch scaled down version of the river will be built in our science lab from MDO Plywood. MDO has a plastic overlay that makes it water proof and easy to cut. It is typically used for the construction of boats and must be purchased in a "true" lumber yard, not a home improvement center. Any imperfections in the fit of the plywood pieces can be corrected with bathroom caulking. SAFETY WARNING: MDO plywood should be cut wearing safety glasses and a dust mask. Students should be given precut sections of the plywood based on their design specifications ( see appendixes A-C).
The width and depth of the river section chosen , as well as an equal embankment and riverbed ratios must be established during the design and construction process to produce accurate erosion and land sculpting experiments.
Collecting Data
Edgewood students will both walk and ride the river over a two day period. The New haven River Keeper, Peter Davis, will assist with the organization of water canoeing. During each session the students will photograph, sketch and script the river, logging areas of particular interest. The photographers will also be responsible for capturing images at regular intervals along the river. This data will be the basis of selection of the river section we build.
The photographs, sketches and script will be posted on a wall in the classroom in order of location on the river. This will allow viewing during the selection process. The students will use the following criteria for selection :
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1.The model can be no longer than 10 feet or 100 feet of river with a 1 inch to 1 foot ' conversion ratio.
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2.The section of river must be easily accessible for data and measurement collection.
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3.The section should have diverse river features.
The section of the West River selected will be measured at 1 foot intervals. Measurements will include: depth, width and contouring. River bed features and 3 feet of embankment features will be logged for reproduction in our science lab. All materials used in the reproduction will come directly from the West River. Prior to this unit river plants will be grown in our grow lab for use during the West River Reproduction.
Rate of Flow on Erosion and Land Sculpting
Controlling rate of flow will allow the students the opportunity to explore river changes that have occurred over long periods of time. It will also encourage them to formulate hypotheses of future changes. The ability to not only investigate past river activity, but to apply this information to the future will instill in each of of the students the power to understand and perhaps effect change in our communities.
Students will reproduce detailed embankment contours, features and plant life maps on graph paper. These maps will ensure that each experiment is approximately of equal values. Since all the variables in an experiment could never be controlled in a science lab, it is essential that the students understand the value and limitations of approximation. Little in science is exact. The best that can attained is a good approximation. The maps will be used by cooperative groups to conduct our experiments.
Our water source will be a 15 gallon plastic water tank with spicket, which are easily purchased at home improvement stores. Each group will log the rate of erosion and unique land sculpting that occurs at a specific rate of water flow. Their data collection chart will include water usage per 30 seconds; time elapsed to exhaust the 15 gallon water supply; amount of soil and or debris in the catch basin and pre-embankment and post-embankment measurements.
Each cooperative group will research local precipitation history and the impact this has had on the West River. While researching at the National Climate Data Center (19) website each group will br required to produce three graphs. The first graph will have the smallest data set. Each ensuing graph will have progressively larger data sets. The students will have to make predictions as to the patterns they believe will occur based on each graph. As the data set increases so will the excitement and frustration level of the class. The ability to understand the imited amount of information we truly have in society is critical to scientific research and discussions.
The Natural Diversity Data Base (NDDB) website (20) will allow students to access information on significant natural communities in New Haven. They will use the website to research at least one animal and one plant species that are indigenous to the West River, and the impact changes in the river has on their environment.
Precipitation and local biodiversity data in conjunction with our rate of flow experiments, will be the basis of discussions led by each group in debriefing sessions. The students will apply their research and experiment to local biodiversity. At this point they will decide if further experimentation is needed to support their views or if they wish to move on to independent research topics.
Research Tools
The National Climate Data Center allows access to global and monthly U.S. digital precipitation data, through 1997, for all cooperative and NWS stations. It has some documentation that reaches back as far as 1804. This site has the capability to create graphs to the users specification; therefore making it an indispensable tool for students. Each graph is accompanied by a data set used in its design. Although they will only be required to produce three graphs on local precipitation, the students will be encouraged to explore national and global capabilities during the selection of research topics.
The Natural Diversity Data Base (NDDB) is Connecticut's central repository for information on the biology, population status and threats to the elements of natural diversity. Students can access research on; Connecticut's Butterfly Atlas, endangered, threatened and special concern species in Connecticut, mapping for municipalities project, endangered species, and whip-poor-will and nighthawk surveys. The Natural Diversity Data Base is part of the Environmental and Geographic Information Center, a division of the Connecticut Department of Environmental Protection. (21)
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