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Coastal and Marine Geology Program > National Assessment of Coastal Change Hazards

National Assessment of Coastal Change Hazards

Project Links

Coastal Change Hazards Portal

Coastal Change Hazards: Hurricanes and Extreme Storms

National Assessment of Hurricane-Induced Coastal Erosion Hazards

National Assessment of Shoreline Change

National Assessment of Coastal Vulnerability to Sea-Level Rise

More Information

Impacts and Predictions of Coastal Change during Hurricanes

USGS Science for the Nation's Changing Coasts: Shoreline Change Research

USGS Science for the Nation's Changing Coasts: Shoreline Change Assessment

National Assessment of Coastal Vulnerability to Future Sea-Level Rise

USGS Coastal and Marine Geology Program

Oblique aerial photograph near Rodanthe, NC, looking south along the coast on August 30, 2011, three days after landfall of Hurricane Irene.
Oblique aerial photograph near Rodanthe, NC, looking south along the coast on August 30, 2011, three days after landfall of Hurricane Irene.

Understanding and predicting impacts to coastal communities

Coastal areas are essential to our nation's economic, cultural, and environmental health, yet by nature are changing constantly due to a variety of events and processes. Extreme storms can cause dramatic changes to our shorelines in a matter of hours, while sea-level rise can fundamentally change coastal environments over decades. Often, these changes have a devastating impact on developed areas, such as the loss of homes built on retreating cliffs or dunes eroded by hurricane waves. Sometimes changes can be positive, like when new habitat is created by storm deposits. The need for scientific understanding of how our coasts respond to different hazards is clear. The USGS Coastal and Marine Geology Program is meeting this need with ongoing assessments of change and vulnerability to future change along coastlines in the United States. Through the National Assessment of Coastal Change Hazards (NACCH), the program carries out the unique task of quantifying coastal change hazards along open-ocean coasts in the U.S. and its territories. Coastal communities, emergency managers, and other stakeholders can use the science-based data, tools, models, and other products to enhance coastal resilience.

Hurricane Sandy probabilities of coastal erosion (10/29/12).
Hurricane Sandy probabilities of coastal erosion (10/29/12).

What is the National Assessment of Coastal Change Hazards?

USGS scientists are working to uncover the ways in which our coasts have changed—and will continue to change—over time. The national assessment has a multifaceted approach that quantifies key factors shaping our shorelines over multiple timescales—some that occur in minutes, others over a century. Scientists examine coastal processes, including extreme storm impacts, long-term erosion, and sea-level rise. Through extensive observation, modeling and prediction of these processes, scientists aim to gauge how U.S. shores have historically shifted, and how past changes will affect their vulnerability to future hazards.

Understanding and Predicting Storm Impacts

Hurricanes, nor'easters, and Pacific winter storms are powerful events that generate dangerous waves and surge capable of moving large amounts of sand, destroying buildings and infrastructure, and even taking lives. Through processes like dune erosion, overwash, and inundation, storms reshape our nation's coastline. The storm impacts component of NACCH focuses on understanding the magnitude and variability of extreme storm impacts on sandy beaches. The overall objective is to improve real-time and scenario-based predictions of coastal change to support management of coastal infrastructure, resources, and safety.

Map of the Coastal Vulnerability Index (CVI) for the U.S. Atlantic coast.
Map of the Coastal Vulnerability Index (CVI) for the U.S. Atlantic coast.

Measuring Long-Term Change

Erosion is a chronic problem along most open-ocean shores of the United States and is an increasing threat to growing coastal populations. As beaches erode at increasing rates in some areas, there is a demand for accurate information regarding changes in shoreline position. Understanding how the coast has changed in the past and what factors have influenced those changes guides our understanding of what may happen in the future. To meet the needs of coastal managers and policy makers, the USGS has produced a nationally consistent analysis of shoreline positions and maps of changes along open-ocean sandy shores of the conterminous U.S. and parts of Alaska and Hawaii.

Understanding Vulnerability to Sea-Level Rise

As our oceans rise, what are today's flood water levels will be tomorrow's high tide lines. The sea-level rise component of NACCH assesses the potential impacts of sea-level rise and provides tools for coastal management decision-making. Historical and recent observations of coastal change are combined with model simulations of beaches, barrier islands, wetlands, and coastal aquifers. By combining observations of coastal change with modeled simulations, USGS scientists determine the probability of coastal change due to sea-level rise and communicate this information to managers who face decisions to avoid, mitigate, or adapt to future hazards.

Sharing Science, Informing Policy

As storms continue to impact our coasts and sea levels continue to rise, coastal communities will be faced with difficult decisions regarding coastal development and management practices. The National Assessment of Coastal Change Hazards provides science-based assessments, data and tools about coastal vulnerability to partner agencies, policy makers, and residents to inform strategies for preparing for, mitigating, and responding to our constantly changing coastlines.

Project Contacts

Hilary Stockdon
600 4th Street South
St. Petersburg, FL 33701
Email: hstockdon@usgs.gov
Phone: 727-502-8074
Fax: 727-502-8001
    Rob Thieler
384 Woods Hole Road
Woods Hole, MA 02543
Email: rthieler@usgs.gov
Phone: 508-457-2350
Fax: 598-457-2310
    Nathaniel Plant
600 4th Street South
St. Petersburg, FL 33701
Email: nplant@usgs.gov
Phone: 727-502-8072
Fax: 727-502-8001
    Cheryl Hapke
600 4th Street South
St. Petersburg, FL 33701
Email: chapke@usgs.gov
Phone: 727-502-8068
Fax: 727-502-8001

About the USGS Coastal Marine Geology Program

The USGS Coastal and Marine Geology Program studies coastal and marine resources from coasts and estuaries to the continental shelf and the deep sea, provides expertise, products and tools that address and inform issues shaping our nation.

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Page Last Modified: April 15, 2014 @ 01:51 PM (JSG)