Impact of cyclone on salinity gradient, inundation
Answers
Tropical cyclone‐generated storm surges are among the most deadly and costly global catastrophes. The most severe surge events have killed hundreds of thousands of people and inflicted extraordinary economic losses. For example, the 1970 Bhola Cyclone generated a 9.1 m storm surge in Bangladesh that killed approximately 300,000 people [Frank and Husain, 1971; Dube et al., 1997]. In 2005, Hurricane Katrina inflicted $149 billion in losses (adjusted to 2013 Consumer Price Index), making it the most costly natural disaster in U.S. history [National Climate Data Center, 2014] and three times more costly than any nonstorm surge disaster in the U.S.
From a broader perspective, storm surges may have killed as many as 2.6 million people around the world during the past 200 years [Nicholls, 2003] or an average of 13,000 people annually. This rate fits well with the estimate of 10,000 to 15,000 annual storm surge deaths since 1850 provided by Nicholls [2006] and an annual rate of 15,000 surge deaths provided by Smith [1989]. Most years observe less than this number of surge deaths, as several megacatastrophes in the historical record, like the 1970 Bhola Cyclone, substantially increase the annual fatality average. Nonetheless, as many as 250 million people who live lower than the maximum storm surge level [Intergovernmental Panel on Climate Change, 1994] are vulnerable to inundations from storm surge every year.
Unfortunately, a thorough literature review reveals that no credible source has summarized tropical surge observations or impacts on a global scale. The absence of a tropical surge database leaves coastal populations unaware of coastal flooding events that have already impacted vulnerable areas. Such information would be valuable to people living in high‐risk areas, as well as professionals in the fields of emergency management, insurance, construction, urban planning, health care, science, and engineering. A tropical surge database would also complement data sets that archive global tsunami observations [National Geophysical Data Center/World Data Service, 2015] and nontropical storm surges [Haigh et al., 2015].
A global database of tropical surges has not yet been developed because of several data collection challenges. One of the problems relates to scale, as scientists rely on permanent tide gauges for water level observations, but these gauges are usually distributed too far apart to capture the peak level of tropical surges [Haigh et al., 2013], which tends to be localized [Needham and Keim, 2011]. In addition, high‐magnitude tropical surges often destroy gauges or cause them to malfunction, as observed in Hurricane Katrina in 2005 [Beven et al., 2008; Fritz et al., 2007].
Fortunately, the deployment of numerous mobile gauges [Kennedy et al., 2010; U.S. Geological Survey, 2014] and the completion of high‐water mark field surveys [URS Group, Inc., 2006a, 2006b, 2006c, 2006d; Fritz et al., 2007; Federal Emergency Management Agency, 2008; Fritz et al., 2008, 2009, 2010a, 2010b] have provided an abundance of additional data in the past decade. Also, new technologies, such as airborne and satellite altimetry, are under development for measuring wide swaths of storm surge inundation [Wright et al., 2009]. Therefore, this is an opportune time to compile a comprehensive record of tropical surge inundations from these various sources.
This paper fills this need by providing the first comprehensive review of tropical cyclone‐generated storm surge data sources, observations, and impacts. The term tropical cyclone (TC) is used in this paper to define nonfrontal areas of low pressure that have closed circulation and obtain energy from warm ocean waters. The term hurricane is used to describe this phenomenon in the western North Atlantic and eastern North Pacific basins, when the maximum sustained wind of such storms exceeds 119 km/h, while the word typhoon is used to describe this same phenomenon in the western North Pacific [Landsea, 2011].
Answer:
Explanation:
Storm surge impacts transportation, agriculture, and energy sectors in the WNA. ..... in a small valley with a steep slope facing the source area [Shimozono et al., ..... River Delta of Vietnam, as surges have inundated croplands with salt water.