Sea Level Rise Impacts on Projected Future Growth

Sea Level Rise Impacts on Projected Future Growth

Sea Level Rise Impacts on Projected Future Growth in Newport News & Hampton, Virginia GEOG 594A Ray Moody Analytic Question The cities of Newport News and Hampton occupy the peninsula of Hampton Roads and the lower portion is especially vulnerable to coastal flooding. The area is heavily populated and contains Fort Eustis, Langley Air Force Base and the Newport News Shipyard. Population growth and development will increase with the 322,000 people of Newport News and Hampton gaining an additional 100,000 people over

the next fifty years. The effect of hurricane storm surges today has been examined but what will be the future impact with increased urbanization combined with expected rising sea levels from climate change? Geography The eastern edge of the Peninsula is characterized by a bowl-shaped depression known as the Chesapeake Bay Impact Crater. The crater was created about 35 million years ago by a comet or meteorite. Today it encompasses most of the cities of Poquoson and Hampton, as well as the eastern portions of Gloucester and York counties. Also the Suffolk Scarp (the geological feature that marks where the

Mid-Atlantics Outer Coastal Plain ends and the Middle Coastal Plain begins) occupies the eastern section. Most of Newport News occupies the higher western portion of the Peninsula but the shipyard and downtown section are in the lowest region near the southern tip which is most prone to flooding. Source: Powars, 2000; Ator, et al. 2005. Elevation and topography on the Peninsula. Note the large areas below 3.5 meters especially east of the remnants of the crater. Reality Check Hampton Roads On May 17, 2012, Reality Check Hampton Roads brought together 300 leaders from the political, business, environmental, real estate, and civic realms to envision the future land use of our region. They explored how

Hampton Roads will look in 2035 with the addition of 350,000 more people and 175,000 more jobs. Participants worked in groups of ten at 30 tables assisted by facilitators. Each table placed LEGO blocks to represent new jobs, new standard housing and new workforce housing. Following the mapping exercise the data collected from each cell was entered into computers and assembled in a GIS database. A number of composite maps were developed to show the consensus of the tables. Of these the maps showing future population growth were used in the sea level rise analysis. Source: Hampton Roads Reality Check 2012 Percent Change in Population by 2035 The results of the Reality Check showing

percent change in population. High increase areas for 2035 are assumed to also be high increase areas for next fifty years. High growth areas were identified in eastern Hampton near Buckroe Beach, Fort Monroe Authority, waterfront areas of Newport News and Fort Eustis. High growth areas were along I-64 in the center of the peninsula. FT Eustis Langley AFB Hampton Newport News FT Monroe Authority

Source: Hampton Roads Reality Check 2012 Current Storm Surge Effects The Saffir-Simpson hurricane classification scale was used for storm surge levels. CAT I 1.5 meters CAT II 2.4 meters CAT III 3.7 meters Category I surge inundates marshland and low areas along the east side with some neighborhoods in Poquoson affected. Marshlands around Ft Eustis are flooded. Category II begins to affect many populated areas to include Langley AFB in Hampton. Category III would affect large areas of downtown Hampton and areas of Newport News. Historical records show the worst storm

surges from 1933 and 2003 as approximately 2.4 meters including tide. Sea Level Rise Sea level rise occurs globally as ice melts from glaciers and ice sheets and as oceans warm up. Land subsidence is of concern in Hampton Roads where the main contributors are glacial rebound, faulting and consolidation of sediments in the Chesapeake Bay Impact Crater, and sediment compaction caused by groundwater withdrawals (Boon, Brubaker and Forrest 2010). Land subsidence accounts for approximately one-half to two-thirds of the sea level rise experienced in the Hampton Roads region (Boon, Brubaker and Forrest 2010). Seal level rise and land subsidence combined global average sea level rise projections for the Hampton Roads region currently range from less than half a meter to about two meters by the end of the 21st century . Based on these projections, Fletcher 2009, states that one meter of sea rise over the next century is an appropriate target. For this half century study that amount will be halved to 0.5 meter. Source: Boon, Brubaker and Forrest 2010: Fletcher 2009 CAT I Storm Surge Effects With Sea Level Rise

Langley AFB FT Eustis Hampton Newport News FT Monroe Authority High growth areas affected by the additional sea level rise are annotated in boxes that are examined in greater detail later. Areas affected by the additional sea level rise are in dark blue. CAT I Storm Surge Effects With Sea Level Rise: Fort Monroe The Fort Monroe Authority was created after Fort Monroe was closed and is now open

to private development. The historic fort within the moat remains under National Park control. The historic area floods easily in CAT I conditions. Most of the Island will be flooded by CAT I hurricane by 2065 if sea levels rise at Moderately predicted rates. Private development National Park Service Areas affected by the additional sea level rise are in dark blue. CAT I Storm Surge Effects With Sea Level Rise: East Hampton

Areas of east Hampton near Buckroe Beach will be affected by CAT I hurricanes with high growth areas disproportionately affected by increased sea level rise. Areas affected by the additional sea level rise are in dark blue. CAT I Storm Surge Effects With Sea Level Rise: Langley Air Force Base Flooding at Langley Air Force Base during Hurricane Isabel. Although Isabel wind speeds dropped to CAT I by landfall storm surges with tides reached 2.4 meters in places (CAT II level). Air Force file photo 2003. Additional flooding from sea level rise will have impact on residential areas, runways and operational areas at Langley AFB. CAT I Storm Surge Effects With Sea Level Rise: Fort Eustis

The western area of Fort Eustis is low and marshy. Current development there is limited to higher areas. Future development in that area will be subject to flooding by CAT I hurricanes especially additional flooding from sea level rise which will incur on the high ground. Areas affected by the additional sea level rise are in dark blue. CAT II Storm Surge Effects With Sea Level Rise High growth areas affected by the additional sea level rise are annotated in yellow boxes that are examined In greater detail later. Numerous high growth areas are completed inundated in CAT II conditions with additional sea level rise (small red boxes). Areas affected by the additional sea level rise are in dark blue.

CAT II Storm Surge Effects With Sea Level Rise Hampton Extensive areas are affected by CAT II flooding with additional sea level rise. Three areas of high growth are completely inundated to include most of Langley AFB. Many areas of additional sea rise flooding affect moderate growth residential areas of eastern Areas affected by the additional sea level rise are in dark blue. CAT II Storm Surge Effects With Sea Level Rise: Newport News The additional flooding of a CAT II hurricane with future sea level rise affects waterfront areas of high growth in Newport News. Areas affected are the shipyard and downtown Newport News. Areas affected by the additional sea level rise are in dark blue.

CAT III Storm Surge Effects With Sea Level Rise An additional high growth area is completely inundated in CAT III conditions with additional sea level rise (arrow). Areas affected by the additional sea level rise are in dark blue. Flooding Effects Hampton Category Storm Acres Flooded CAT I CAT I with .5 m sea level rise 4,577

CAT II CAT II with .5 m sea level rise 10,757 CAT III CAT III with .5 m sea level rise 20,788 7,462 14,797 24,007

Newport News Percent Increase in Additional Acres Acres Flooded Flooded from from Sea Level Sea Level Rise Rise Acres Flooded Percent Additional Increase in Acres Flooded Acres Flooded from Sea Level from Sea Level Rise Rise 4,708

2,884 63% 5,731 1,023 21% 1,039 16% 774 8% 6,368

4,040 37% 7,407 8,729 3,219 15% 9,504 The effect of sea level rise on Hampton results in a 63% increase in inundation (2,884 additional acres) in a CAT I storm and an additional 4,040 acres flooded in a CAT II storm. Newport News effects are less pronounced due to its higher ground and steeper western banks. Still Newport News receives an additional 1,023 acres flooded in a CAT I storm and 1,039 additional acres in a CAT II storm. Conclusions

A relatively modest .5 meter of sea level rise over the next 50 years will significantly increase the effect of Category I and II storms in Newport News and Hampton. Sea level rise could flood an additional 3,907 acres in a CAT I storm, 5,079 acres in a CAT II storm, and 3,993 acres in a CAT III storm. The effects are worse in Hampton where CAT I sea level rise increases flooding 63%. Hampton has the most areas of high growth as well. Future areas of high growth affected by sea level rise are Langley AFB, eastern Hampton and Buckroe Beach, Fort Monroe Authority, Newport News shipyard, and Fort Eustis. Recommendations Improved Lidar data for Hampton Roads will increase accuracy of analysis. Continue to refine land subsidence and sea level rise data. The region should continue to study strategies for adapting to coastal flooding both in the short term as well as the long term. Federally administrated areas prone to sea level rise such as FT Eustis and Langley Air Force Base should mitigate effects. Localities and Fort Monroe Authority should be aware of new development in designated high risk areas and the importance of continuing current mitigation

efforts. Source: Climate Change In Hampton Roads Phase III: Sea Level Rise In Hampton Roads, Virginia 2012

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