Overview: Flooding and erosion in Alaska

damage from the 1964 Alaska EarthquakeErosion and flooding in Shishmaref, Alaska, threatens both infrastructure and lives. Tony Weyiouanna

Introduction

Flooding and erosion affect over 87% of the rural communities spread across Alaska’s rivers and coastlines (GAO 2003, 2009; USACE 2009; IAWG 2009). Although the occurrence of these hazards is broadly established, there is minimal monitoring equipment or mapped data throughout Alaska.

Alaska is subject to glacial and nearby processes that make permafrost and sea ice key controlling factors of coastal erosion and flooding. Later forming offshore and land-fast sea ice allow coastal storm waves to build and leave beaches unprotected from wave attack (Simmonds and Keya 2009, Douglas 2010, Vermaire et al. 2013, Terenzi et al. 2014). Thawing permafrost leads to faster rates of erosion along permafrost-rich coastal bluffs (Gibbs and Richmond 2015) and sinking of already low-lying regions. Rates of erosion vary throughout the state with the highest rates measured on the arctic coastline at more than 60 feet per year (18 meters) (Gibbs and Richmond 2015). Longer sea ice–free seasons, higher ground temperatures, and sea level rise are expected to exacerbate flooding and accelerate erosion in many regions, leading to the loss of land habitat into the future (Gibbs and Richmond 2015).

How to report flooding or erosion

NOAA National Weather Service

Report a weather condition for your area to the National Weather Service Weather Forecasting Offices (WFO) storm reporting web pages or call directly. Reports are sent directly to the NWS weather forecasting desk.

Local Environmental Observer (LEO) Network

To learn more about observations and events reported across Alaska, visit the Local Environmental Observer (LEO) Network webpage. LEO is composed of experts who collect observations about unusual environmental events in their communities. They apply local and traditional knowledge, Western science, and modern technology to record and share observations and to raise awareness about conditions in the circumpolar north. LEO participants are in more than 100 communities in Alaska and Canada.

Reporting guide for flooding or erosion
Scenario Agency/Contact Telephone Available Details
You are concerned with long-term erosion or flooding hazards, are interested in more information, or conducting monitoring.

Alaska Division of Geological & Geophysical Surveys Coastal Hazards Program (907) 451-5026 Mon.–Fri.
8 am–4 pm
Program Details
You see an erosion event or flood and would like to report immediately. National Weather Service Fairbanks (907) 458-3708 24 hr  
National Weather Service Anchorage (907) 266-5167
option 4
24 hr  
You observe erosion or flooding and would like to report as an observation. LEO Network     About LEO Network

Community-based monitoring programs

Erosion

A protocol for monitoring coastal erosion has been developed by the Alaska Division of Geological & Geophysical Surveys (DGGS), University of Alaska Fairbanks (UAF), Bristol Bay Native Association, and Alaska Sea Grant. Collaborators are working with local teachers and Tribal Environmental Coordinators throughout the state to collect baseline erosion surveys. An erosion monitoring site includes a time-lapse camera and stake monitoring setup, as well as Emery rods (measuring stakes) for data collection on beaches. The local collaborator takes ground measurements and sends data to DGGS. DGGS and UAF then process the data to measure how much shoreline erosion has occurred and note significant events during data collection.

Flooding

DGGS facilitates a variety of water level observations throughout the state. Autonomous water level sensor systems can be placed on bridges and other coastal infrastructure to monitor the elevations of water levels in real-time. Tide staffs are rulers placed on infrastructure (buildings or power poles) that are surveyed to determine their absolute elevation. Once installed, a local collaborator can document water levels relative to the tide staff, whether they are daily measurements or only during extreme storm events. Flood elevations can also be extracted from digital elevation models if photographs of flooding are taken during a storm event (for methods see Storm water level feature extraction from digital elevation models using intra-storm photographs).

Resources and discussion

For more information

For more information about erosion or flood monitoring, contact the DGGS Coastal Hazards Program at Jacquelyn.overbeck@alaska.gov or call 907-451-5026.