Science and Technology News

Thursday, August 11, 2011

Assessing the Impact of Future Sea Level Rise

By Bradley Peters, NREIPIntern at SPAWARSystems Center Pacific

Mission readiness throughout the military depends on the global reach of the Navy, which ensures the safety of our country and allies. Despite tremendous advancements in weapons technology and naval engineering, Navy vessels still rely heavily on the use of land-based naval facilities at home. Navy installations must be prepared to repair, resupply, and turn aroundships in an appropriate amount of time to ensure that the fleet is able to carry out missions throughout the world’s oceans. In the future, climate change and related events, including sea level rise, may impair the Navy’s ability to maintain the land-based facilities that are essential to mission readiness.

San Diego in particular hosts a large Navy presence occupied in research and direct mission support capacities, both uniformed and civilian. As of 2008, there are more than 100,000 uniformed members of the Navy in the San Diego region. It is of critical importance to the livelihoods of these service members and their civilian support to recognize and evaluate future impacts on Navy operations in the area.

Throughout California, research teams have been evaluating the impacts of future sea level rise on the West Coast for about a decade. In 2008, a California state-funded assessment of sea level rise scenarios found that even by conservative estimates, local relative mean sea level in San Francisco will be higher than the highest local relative mean sea level ever recorded in San Francisco by 2100.

Coupled with projections of increased impact of storms and El NiƱo events,this information leads scientists to believe that the impact of sea level rise in southern California may be particularly acute.

So where does this leave San Diego, its military, and its civilian employees? With little speculation, some have concluded that sea level rise will make many naval coastal facilities virtually unusable. Service piers and docks, which rarely sit more than a few meters above sea level, could face a wide range of degradation scenarios, from loss of usage to outright inundation. If sea level rise were to impact facilities in this way, approximately sixty Navy ships that currently berth in San Diego may have to find another port to call home.

In evaluating the specific impacts of sea level rise on Navy installations, it is logical to turn to an illustration tool as powerful as geographic information systems (GIS). My mentor, MarissaBrand, and I have used GIS in collaboration with employees at the Environmental Sciences Branch of SSC Pacific and other researchers to produce comprehensive maps of Navy installations, cross reference these with available LIDAR elevation data, and determine whichfacilities are at risk. Facilities like Camp Pendleton, located in northern San Diego County, are guarded by high sea cliffs, and so are unlikely to face significant impacts from sea levelrise. Naval Amphibious Base Coronado, on the other hand, may eventually be completely underwater. In general, GIS helps us determine which facilities will be impacted at various potential and perhaps predictable scenarios, keeping in mind that facilities may be completely unusable well before they are “underwater.”

GIS provides us the ability to put both a dollar value on potential losses as well as judge impacts to mission readiness. Inundation of a baseball field, for example, would have less of a monetary impact than the inundation of Pier Bravo at Naval Air Station North Island, which has a projected replacement cost of more than $130 million. Critical infrastructure, including utilities and airport facilities may also be at risk, and efforts to manage and protect endangered species on military installations may be compromised. For this reason, evaluating the potential impacts of sea level rise on military installations is critically important.

As part of the NREIP program, I was fortunate enough to receive a tour of the USS Wayne E.Meyer, an active-duty navy vessel. The dedicated men and women who operate this ship indefense of the United States depend on the availability and proper function of land-based Navy installations in order to achieve their mission objectives. It is therefore extremely important thatwe serve them by predicting and planning for the conditions of the future.

Brad Peters is a recent graduate of the College ofWilliam and Mary with a BS in Geology. Peters will begin work for his PhD in the fall at Scripps Institution of Oceanography in San Diego,CA, where he will focus on research in igneous andmetamorphic petrology and volcanology. As a part of the NREIP program, Brad also participated in a numerical modeling project that aims to asses the impact of sea level rise and storm events on beach morphology in San Diego County. In addition to being an aspiring scientist, Brad is also an avid violinist and rower.

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