Simulating and projecting future impacts of sea-level rise on Majuro Atoll

Ocean water floods over a lawn and into a house along a low shoreline.
The increasing frequency of ocean inundation onto low-lying atolls like Majuro demand better estimates of future conditions for managers and decision-makers to consider.

The Republic of the Marshall Islands (RMI) spreads over 29 atolls and has a population of over 50,000 people; over 27,000 of those people live on the Majuro Atoll, RMI’s capital. Sea level rise threatens the very existence of RMI as high-end projections of sea level rise by the end of the century exceed the average elevation of these low atoll reef islands. Already, waves wash over Majuro during “king tides” when strong winds blow from the west across the broad lagoon, or when there are high open ocean waves. Flooding waves breach island shores in multiple locations and wash into homes, cemeteries, across roads, and into commercial districts. Over the past decade, there has been a widespread exodus of residents to locations in Hawaiʻi and the continental U.S. as life becomes increasingly untenable on these low sand and gravel islands.

In order for Majuro and RMI leaders and decision makers to plan and implement a strategy for moving forward, scientific information and geospatial data are needed to model the timing and spatial pattern of future flooding in the first and most vulnerable areas. This project team will use a digital elevation model (DEM), currently under development, for the Majuro Atoll to model sea level rise and develop flooding simulations to help identify vulnerable areas. The team will also collect topographic and bathymetric data on Majuro to extend the areas covered by the DEM to provide a more comprehensive view of future wave flooding associated with sea level rise.  In later years of the project, the team plans to utilize existing data on groundwater and collect new information on Majuro’s water table to model and understand water table dynamics in order to simulate inundation of saltwater into groundwater due to sea level rise. A primary goal of this project is to distribute project deliverables and provide training in their interpretation and application to Marshallese government agencies to inform mitigation and adaptation.





Charles Fletcher
Professor of Earth Sciences, UH Mānoa