A numerical study of storm surge and inundation in the CroataneAlbemarleePamlico Estuary System Machuan Peng, Lian Xie ) , Leonard J. Pietrafesa Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Box 8206, Raleigh, NC 27695-8208, USA Received 5 July 2002; accepted 31 July 2003 Abstract An integrated storm surge and inundation modeling system is used to simulate the storm surge and inundation in the CroataneAlbemarleePamlico Estuary System in eastern North Carolina under the influence of 10 hypothetical Category 2 and 3 hurricanes representing typical historical hurricane scenarios in the study region. The integrated storm surge and inundation modeling system is numerically stable in the complex and shallow CAPES environment under hurricane forcing conditions. For an assumed northward or northeastward moving Category 3 hurricane with a translation speed of 25 km/h, the peak storm surge occurs along the western Pamlico Sound and western Albemarle Sound. The most severe flooding as measured by inundation area is in the Pamlico River mouth region where the flooding area reached 500 km 2 . In general, a more intense or larger hurricane (lower minimum central pressure, MCP or larger radius of maximum wind, RMW) produces higher storm surge and a larger inundation area in the entire region. For the cases considered in this study, the storm surge height and inundation area are more sensitive to MCP than to RMW. Slower translation speed produces higher storm surge, and thus larger inundation area, but the sensitivity of storm surge to storm translation speed can be vastly different for different storms. Ó 2003 Elsevier Ltd. All rights reserved. Keywords: storm surge; inundation; numerical modeling; coastal flooding; hurricane 1. Introduction The CroataneAlbemarleePamlico Estuary System (CAPES) (Fig. 1) in eastern North Carolina is the largest lagoon system and the second largest estuary (next to Chesapeake Bay) in the United States (Pietrafesa et al., 1986). It covers a total area of approximately 5500 km 2 . The CAPES comprises primarily two major bodies of water, Pamlico Sound (w120 km!40 km) and Albemarle Sound (w70 km!20 km), which are linked by the relatively small Croatan and Roanoke Sounds (Pietrafesa et al., 1986). The average water depth of the CAPES is only 4.5 m, though the water depth ranges from 2 m around the perimeter or near the shoals to approximately 7 m in the deepest basin. The CAPES is separated from the Atlantic Ocean by the Outer Banks, a chain of emergent bar-built islands on their east sides. Three narrow inlets, Oregon, Hatteras and Ocracoke Inlets, along the Outer Banks, contribute to the water exchange between the CAPES and the Atlantic Ocean. The CAPES faces frequent threats from tropical and extra-tropical cyclones. Damages associated with these cyclones derive from strong winds, storm surge, and in- land flooding. As a function of the combination of envir- onmental factors and the socioeconomic structure of the region impacted, the impact can vary tremendously. However, amongst the above suite of factors, coastal and inland flooding is known as the most dangerous to human life and property. The purpose of this study is to investigate the feasibility of modeling hurricane-induced currents, storm surge and inundation in the CAPES using a three-dimensional computer model and to im- prove our understanding of the hydrodynamic responses of the CAPES to the passages of hurricanes. Numerical studies of hurricane-induced storm surge and circulation in the CAPES began in the mid-1970s. These studies were mainly published in technical reports (Amein and Airan, 1976; Pietrafesa et al., ) Corresponding author. E-mail address: lian_xie@ncsu.edu (L. Xie). Estuarine, Coastal and Shelf Science 59 (2004) 121e137 0272-7714/03/$ - see front matter Ó 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.ecss.2003.07.010