|INTERVIEW with Sharon Lingle, Geologist, Division of Geological Survey
What do you do to protect and improve Ohio’s coastal region?
I research the geology and geological processes of Ohio’s Lake Erie coast to discover ways to reduce erosion and re-establish beaches. Geological processes, such as erosion and deposition, can be affected by human development.
For example, construction of harbor structures in the past century have interrupted sand transport resulting in sand retention on one side of a harbor and erosion on the other side. As the shore and beaches on the downdrift side of harbors eroded, property owners built structures to slow erosion on their property. This increase in shore protection structures contributes to further erosion and reduction of the natural sand supply.
My research for a sand-monitoring project will help generate solutions to this complex problem. The primary goal of this project is to inventory the volume of sand in various Ohio beaches and nearshore zones.
How do you conduct this research?
I select representative beaches and nearshore zones to monitor and conduct fieldwork based on previously collected data. The geology of Ohio’s Lake Erie includes consolidated material, such as shale and limestone bedrock and unconsolidated material, such as sand, silt and clay. To estimate the sand volume for the Ohio portion of Lake Erie, profile lines are constructed perpendicular to the shoreline at sites with different geologic frameworks, shoreline orientation and nearshore slopes. The diagram below is a profile of a site in Ashtabula County.
I measure the shoreline orientation using a Brunton compass as seen in the photo below. The profile is then oriented 90 degrees from the shoreline. Several types of data, including land elevation, sand thickness and bathymetry data, are acquired along the profile line on the beach and in the nearshore zone.
I use surveying equipment, such as the Geodimeter 464 in the photo below, to measure land elevation of the beach. A hydraulic probe is used to measure sand thickness along the entire profile line. A depth sounder is used to measure bathymetry in the nearshore zone.
In addition, I collect sand samples for grain size analysis.
The total volume of sand in the profile includes the volume obtained in the beach and the nearshore zone, which uses the measured thickness and width of the profile for a unit length of shoreline. Beach width for a unit length of shoreline to sand volume ratios will be developed for each profile.
Historic and current aerial photographs are used to determine the length and width of beaches. Volumes for the entire length of beaches can then be extrapolated using the representative ratios and past and current conditions can be compared. The findings will be used to develop a regional model for estimating required volumes of sand to re-establish beaches.
Are there other ways your research will be used?
Yes. It will be used to assist local communities and individual property owners to consider environmental friendly ways to address erosion and flooding problems as part of the Lake Erie Shoreline Erosion Management Plan. Additionally, I will help determine future geological research needs so that the plan is science-based.
Do you communicate your research to the public?
Yes. I am available to answer questions that people have regarding the geology and geologic processes associated with Ohio’s Lake Erie shore and can provide numerous publications and maps on the geology of the shore, nearshore and beach zones.
What is most challenging about your job?
Both weather and lake conditions have to be just right in order to collect good data from the beach and nearshore zones. This can prove tricky when estimating when to conduct fieldwork. Weather and lake conditions can be calm at one moment and then change drastically. When conducting fieldwork from the boat, public access is sometimes far from the site and certainly can make for a rough ride back to the boat ramp.