BACKGROUND
Firgure 1: Sea Level Rise Projections in Norfolk, VA. Sourced from Atkinson, L. P., Ezar, T., & Smith, E. (2013). Sea Level Rise and Flooding Risk in Virginia. Sea Grant Law and Policy Journal, 5(2), 3–14. Retrieved from http://nsglc.olemiss.edu/sglpj/vol5no2/2-atkinson.pdf
As the world’s atmosphere continues to rise in greenhouse gas concentrations, the climate faces a variety of potential threats, including increased amounts of precipitation as well as sea level rise linked to glacial melting. In recent years, sea level height around the Chesapeake Bay region has been increasing dramatically faster than the global mean sea surface height, with a yearly average increase of 3.6mm, over twice the amount of the global increase at 1.8mm (Najjar et al., 2010). This is one of the highest rates of sea level rise in the US. This region is particularly vulnerable to sea level rise due to the combination of rising waters with sinking land due extensive groundwater pumping leading to land subsidence. Using a semi-empirical approach developed by Stefan Rahmstorf, a “Professor of Physics of the Oceans”, Najjar et al. found that in the Chesapeake Bay region sea level is predicted to rise 700mm-1600mm (2.3ft - 5.2ft) by the year 2100. In addition to sea level rise, increased precipitation as well as extreme precipitation events are expected to increase with the changing climate. Due to the US Southeast region being in a transition zone between the Northeast and Southwest, it is difficult to exactly predict the changes in precipitation. However, according to the National Climate Assessment report, northeastern areas of the Southeast region are expected to experience wetter conditions consistent with the predicted precipitation patterns of the Northeast region. From this, we can conclude that Virginia will likely experience an increase in precipitation over the following years, primarily in the Winter and Spring seasons.
Many cities have been increasingly concerned about the encroaching impacts of climate change and have been preparing climate adaptation plans to help prepare the city for the changes to come, primarily changes in temperature as well as precipitation. The basic outline of these reports is for first a risk analysis to be done, followed by a mitigation and adaptation strategy in response to the calculated risks. For example, the Climate Ready DC report prepared by Washington D.C. addressed that the 100-year rain event will have increased from today’s level of 8 inches to almost 14 inches by the year 2080. This was followed by a climate risk assessment on built infrastructure and community resources in the D.C. area. Low-lying coastal cities, like Norfolk, Virginia, are particularly vulnerable due to their increased risk of storm surges along with flooding events in combination with the risk of sea level rise. In 2014, Norfolk released their own Coastal Resilience Strategy in response to preparing for the impacts of coastal flooding. Later, in 2016, Norfolk released Norfolk Vision 2100, in which an asset mapping exercise was executed to hear back from Norfolk residents on areas they love the most in order to locate and preserve the areas most important to the citizens. The main purpose of this exercise was to outline the future steps the city would take in their development process. However, these reports lacked a clear built asset analysis that determined the calculated amount of exposure of each asset in the city in order to best understand the flood risk associated with an area.