Sediment Dynamics in the Elwha By Siberian Tigers
Question: How and where has the removal of the dam physically effected the structure of the Elwha river?
Prior Knowledge • Dam removal would result in lower water level • Lower water level would carry sediments
Materials • Computer with Google Earth Field Materials: • Boots, tripods, GPS, Camera + Memory Card, Batteries
Procedure • Pick six sites on Google Earth along the Elwha river with noticeable differences between before the dam was removed and after (Find differences using the time slider) • Visit each site and take pictures • Analyze structure of the river through pictures taken
2009 2012 Data Point 1 47.972657° -123.593665° A river blowout is observed at Cat Creek as it enters the Elwha, possibly because of dam removal. Trees are in the bottom of the valley.
Data Point 2 47.992657°-123.600642°This picture of Lake Mills is a good example of the change of the water level after the dam was removed. 2009 2012
Data Point 347.949093°-123.558428°The River in 2009 is a curve and now in 2012 it is a straight river. Near Humes ranch 2009 2012
Data Point 4 48.080498°-123.570295°The water level got a lot lower in 2012.Lake Aldwell 2009 2012
Data Point 548.121043°-123.556585°Elwha River near the State Fish Hatchery 2009 2012
Results/Analysis We observed that the removal of the dam and the declining water levels in the Elwha river have caused the build-up of sediment at the bottom have been carried down the river and have caused extensive erosion along the river and have overall physically changed the river.
Hypothesis If the sediment at the bottom of the Elwha river gets carried down to the delta there will be a significant change in the structure of the river because the water currents will erode different parts of the banks, and the sediment will build up.
Future Research Projects • Plan: • Monitor points for 5 years • Set up equipment at the 6 points • Collect data/photos and record results
Importance of our project • Help land managers increase salmon runs • Help land managers understand how the river affects other habitats, such as forests.