Type of Submission
Poster
Keywords
Cedar Lake, lake contour, lake depth, lake volume, bathymetry, sediment infill, surfer software, environmental geology, environmental science, geoscience
Abstract
In the fall of 2012, the CU Environmental Geology class did an assignment which produced a bathymetry (bottom-contour) map of Cedar Lake. Although the depth measurements using stadia rods and the position measurements using handheld GPS units were somewhat crude, the end result was a map that seemed to be a very reasonable depiction on the lake bottom configuration. In the fall 2014, measurements were again made as a part of an ongoing assessment to determine if sediment infill was occurring in the lake. The data gathering techniques duplicated those used in 2012, including equipment used. The primary difference between the two measurement events involved the number of depth readings taken, 364 readings were taken in 2014 and 138 were taken in 2012. Measurement locations and depths were determined by using Garmin GPS units and surveyors’ stadia rods. The data had to be processed using a variety of file types for the different software applications that were used. A Golden Software package called Surfer 8 was used to produce the bathymetry (bottom contour) maps of the lake and to calculate the water volume. The contour maps were then transferred into ArcGIS imagery for final presentation. The data collected in 2012 produced a volume of ~1,320,000 cubic feet and the data collected in 2014 produced a volume of ~1,450,000 cubic feet. This 130,000 cubic feet difference is an increase of almost a million gallons. This increase of water implies that there was not sediment infill but a sediment loss. Nearly 5 to 6 inches of additional water across the 6 acres of the lake surface would be required to produce this volume. During the past two years the lake has not been altered (dredged, for example) in any way to create a volume increase. This significant increase of water shows that the data collection method may have been too inaccurate to predict the sediment infill rate of the lake. Or, more likely, the increase in number of readings in 2014 has produced a more detailed bathymetry map than was produced in 2012. This, in turn, creates a volume discrepancy.
Faculty Sponsor or Advisor’s Name
Thomas Rice
Campus Venue
Stevens Student Center
Location
Cedarville, OH
Start Date
4-1-2015 11:00 AM
End Date
4-1-2015 2:00 PM
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Progressive Assessment of Lake Depths in Cedar Lake
Cedarville, OH
In the fall of 2012, the CU Environmental Geology class did an assignment which produced a bathymetry (bottom-contour) map of Cedar Lake. Although the depth measurements using stadia rods and the position measurements using handheld GPS units were somewhat crude, the end result was a map that seemed to be a very reasonable depiction on the lake bottom configuration. In the fall 2014, measurements were again made as a part of an ongoing assessment to determine if sediment infill was occurring in the lake. The data gathering techniques duplicated those used in 2012, including equipment used. The primary difference between the two measurement events involved the number of depth readings taken, 364 readings were taken in 2014 and 138 were taken in 2012. Measurement locations and depths were determined by using Garmin GPS units and surveyors’ stadia rods. The data had to be processed using a variety of file types for the different software applications that were used. A Golden Software package called Surfer 8 was used to produce the bathymetry (bottom contour) maps of the lake and to calculate the water volume. The contour maps were then transferred into ArcGIS imagery for final presentation. The data collected in 2012 produced a volume of ~1,320,000 cubic feet and the data collected in 2014 produced a volume of ~1,450,000 cubic feet. This 130,000 cubic feet difference is an increase of almost a million gallons. This increase of water implies that there was not sediment infill but a sediment loss. Nearly 5 to 6 inches of additional water across the 6 acres of the lake surface would be required to produce this volume. During the past two years the lake has not been altered (dredged, for example) in any way to create a volume increase. This significant increase of water shows that the data collection method may have been too inaccurate to predict the sediment infill rate of the lake. Or, more likely, the increase in number of readings in 2014 has produced a more detailed bathymetry map than was produced in 2012. This, in turn, creates a volume discrepancy.
