State of the Beach/State Reports/PA/Beach Erosion
|Bad and Rad
|Sea Level Rise
CRM has conducted numerous studies since 1975 identifying the serious bluff recession
and shoreline erosion hazards of storm events during periods of higher lake levels in
Lake Erie. During periods of higher lake levels, storm events will produce a surge that
inundates and erodes shoreline beaches and makes contact with dwellings in the back
beach areas causing structural damage and flooding. In undeveloped shoreline areas
wave contact with unconsolidated materials making up the stratigraphy of the bluff will
cause serious erosion of the lower bluff face, destabilizing the entire bluff face and
causing bluff recession and retreat of the bluff crest which will threaten structures
overlooking the lake. Lake Erie is currently in a period of rising lake levels.
In their draft Assessment and Strategy (June 2010), CRM wrote:
- "The significant changes under Hazards Research and Monitoring have to do with the use of Lidar technology in analyzing changes in bluff stability to get a much more detailed and accurate reading on bluff recession rates. CRM staff analyzed existing 1998, 2006 and 2007 Lidar data to create a baseline and are working with the ACOE to obtain Lidar data in 2011, then will finish an analysis to plan how to use Lidar coverages to either replace or supplement an existing monitoring system."
- Maps of Tentatively Identified Bluff Recession Hazard Areas
- Aerial Photography Depicting Geographic Locations of Proposed Tentatively Designated Bluff Recession Hazard Areas
- A table showing Summary of DEP Control Point Monitoring Data
- Transects and Maps for Bluff Evaluations
A key reference document is National Assessment of Historical Shoreline Change: A Pilot Study of Historical Coastal Bluff Retreat in the Great Lakes, Erie, Pennsylvania (2009). Also see here.
Decade-scale coastal bluff retreat from LiDAR data: Lake Erie coast of Pennsylvania, USA states:
- "Rates of bluff retreat derived using DSAS vary from unresolvable to as much as 7 m/yr, averaging less than 0.3 m/yr which is consistent with longer-term rates derived by others."
The Coastal Resources Management Program utilizes Geographic Information Systems (GIS) and Aerial Photography to effectively manage the coastal zones. Some current and past activities of interest include:
- Application of a remote sensing technology called Lidar (Light Detection and Ranging) to determine bluff recession
- Use of GPS (Global Positioning System) and GIS technology to record and analyze control point monitoring for bluff recession rates
- Multi-year photointerpretation for wetland monitoring
- Locating and tracking CRM grant projects
- Maintaining GIS datasets for performance measures tracking to NOAA
Links for more information:
Determination of Sediment Loading Potential to Pennsylvania Lake Erie Coastal Waters Due to Bluff Erosion and Storm Water Discharge Ravines (2001) was a investigation that gathered data including the global positioning system location, bluff slope, stratigraphic sections present, thickness of each stratigraphic section, degree of erodibility, presence of groundwater, vegetative cover, land use in the upland and the general geometry of each site. Project personnel also collected and analyzed samples of sediment from each stratigraphic unit to test for sand, silt and clay fraction composition. By combining the results of the analyses with the amount of recession occurring between 1982 and 1998, project staff estimated the sediment loading along the Pennsylvania reach.
The Heinz Center's Evaluation of Erosion Hazards, conducted for the Federal Emergency Management Agency (FEMA), studied the causes of coastal erosion hazards and proposed a variety of national and regional responses. The study, published in April 2000, concentrates on the economic impacts of erosion response policies as well as the cost of erosion itself to homeowners, businesses, and governmental entities.
A NOAA website that has graphs of sea level data for many coastal locations around the country over the last 40 to 50 years and projections into the future is Sea Levels Online.
NOAA Shoreline Website is a comprehensive guide to national shoreline data and terms and is the first site to allow vector shoreline data from NOAA and other federal agencies to be conveniently accessed and compared in one place. Supporting context is also included via frequently asked questions, common uses of shoreline data, shoreline terms, and references. Many NOAA branches and offices have a stake in developing shoreline data, but this is the first-ever NOAA Website to provide access to all NOAA shorelines, plus data from other federal agencies. The site is a culmination of efforts of NOAA and several offices within NOS (including NOAA’s Coastal Services Center, National Geodetic Survey, Office of Coast Survey, Special Projects Office, and Office of Ocean and Coastal Resource Management) and other federal agencies to provide coastal resource managers with accurate and useful shoreline data.
A related site launched in 2008 is NOAA Coastal Services Center's Digital Coast, which can be used to address timely coastal issues, including land use, coastal conservation, hazards, marine spatial planning, and climate change. One of the goals behind the creation of the Digital Coast was to unify groups that might not otherwise work together. This partnership network is building not only a website, but also a strong collaboration of coastal professionals intent on addressing coastal resource management needs. Website content is provided by numerous organizations, but all must meet the site’s quality and applicability standards. More recently, NOAA Coastal Services Center has developed a Sea Level Rise and Coastal Flooding Impacts Viewer as part of its Digital Coast website. Being able to visualize potential impacts from sea level rise is a powerful teaching and planning tool, and the Sea Level Rise Viewer brings this capability to coastal communities. A slider bar is used to show how various levels of sea level rise will impact coastal communities. Completed areas include Mississippi, Alabama, Texas, Florida, and Georgia, with additional coastal counties to be added in the near future. Visuals and the accompanying data and information cover sea level rise inundation, uncertainty, flood frequency, marsh impacts, and socioeconomics.
Erosion Contact Info
J. Samantha Burton
Coastal Resources Program
Program Analyst/GIS & CNPP Coordinator
Telephone: (717) 772-5635
Hazard Avoidance Policies/Erosion Response
See the Erosion Response section.
|State of the Beach Report: Pennsylvania