Coastal USA

Growing coastline population and increasing density 

 Between 1960 and 2008, the population in coastline counties along the Gulf of Mexico soared by 150 percent, more than double the rate of increase of the nation's population as a whole. This area is home to nearly 14 million residents. Eighty-seven million people live in coastline counties, including more than 41 million in the Atlantic and 32 million in Pacific counties. In 1960, only 47 million lived in coastline counties, an increase of 40 million (U.S. Census Bureau). In 2010, 39 percent of the U.S.  population lived in Coastal  Shoreline Counties (less than  10 percent of the total land area excluding Alaska). The population density of Coastal  Shoreline Counties is over six times greater than the corresponding inland counties. (NOAA  National Coastal Population Report ) Coastline counties along the Atlantic and Gulf of Mexico coasts and the Hawaiian Islands account for nearly two-thirds of the nation's coastline population. They are home to four of the nation's ten most populous counties. These counties are also vulnerable to one of nature's most significant threats: hurricanes.  

 Sea level rise 

Global mean sea level increased by 20±5 cm over the period 1901 to 2018 with an accelerated rate since the 1960s to 3.7±0.5 mm/yr for 2006–2018 (IPCC, 2021). Since 2020, the increase of the Sea Level Rise along the US Atlantic coast is higher than the global mean (Domingues et al., 2018; Mitchum et al., 2017), The frequency of coastal flooding events has suffered a significant increase on the South Atlantic coast (Sweet et al., 2017).  

 Aging infrastructure on the coastline is getting more vulnerable. 

 The impact of saltwater generates corrosion and degradation of the structures located in the shoreline. 

Climate change makes things worse: aging infrastructure is subjected to increasingly aggressive conditions. These processes increase vulnerability, higher risks, and expected losses under environmental hazards. 

 Risk assessment is necessary for planning and decision-making and for emergency readiness. 

 Risk assessment procedures, as the ones employed by ENRIR, based on FEMA-HAZUS methodology, and other similar tools, are needed to estimate expected losses. These methodologies are essential for planning and decision-making. Risk assessment methodologies also support emergency readiness.