Janneli Lea A. Soria

Repeat Storm Surge Disasters of Typhoon Haiyan and Its 1897 Predecessor in the Philippines

AbstractOn 8 November 2013, Typhoon Haiyan impacted the Philippines with estimated winds of approximately 314 km h-1 and an associated 5–7-m-high storm surge that struck Tacloban City and the surrounding coast of the shallow, funnel-shaped San Pedro Bay. Typhoon Haiyan killed more than 6,000 people, superseding Tropical Storm Thelma of November 1991 as the deadliest typhoon in the Philippines. Globally, it was the deadliest tropical cyclone since Nargis hit Myanmar in 2008. Here, we use field measurements, eyewitness accounts, and video recordings to corroborate numerical simulations and to characterize the extremely high velocity flooding caused by the Typhoon Haiyan storm surge in both San Pedro Bay and on the more open Pacific Ocean coast. We then compare the surge heights from Typhoon Haiyan with historical records of an unnamed typhoon that took a similar path of destruction in October 1897 (Ty 1897) but which was less intense, smaller, and moved more slowly. The Haiyan surge was about twice the heig...

Integrating different records to assess coastal hazards at multi-century timescales

ABSTRACT Switzer, A.D., Yu, F., Gouramanis, C, Soria, J, Pham, T.D. 2014. An integrated approach to assessing coastal hazards at multi-century timescales. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 723–728, ISSN 0749-0208. In many places on earth, the written record of coastal flooding events from tropical cyclones (typhoons, hurricanes) and tsunamis is too short or inconsistent to accurately assess the hazard posed by both kinds of event on scales beyond those of the average human lifespan. In this paper we summarize an integrated research paradigm that incorporates instrumental, historical, archaeological and geological records to extend the record of coastal flooding events to generate a multi-century analysis of recurrence interval for coastal flooding, thus, improving long-term risk assessment. The two primary factors in assessing risk from coastal hazards are frequency and magnitude. These can be addressed through field and modeling studies of washover deposits where they are found. We also summarize recent advances in the identification of overwash events from the geological record and report on the progress to distinguish storm and tsunami deposits. The recent advances have increased the utility of tsunami and storm deposits to improve coastal risk assessment.

Ground penetrating radar (GPR) survey of formerly mined coastal sand in central Vietnam: a rapid, non-invasive method for investigating the extent and impact of mined areas

 Abstract— Ground Penetrating Radar (GPR) offers a non- invasive, high-resolution subsurface imaging method that can be used to investigate and characterise the sedimentary features and depositional history of various coastal deposits. GPR utilises the electromagnetic wave properties in the megahertz frequency range and can generate 2D and 3D images of the subsurface to identify coastal depositional features to a depth in excess of 20m. In this study we use a series of GPR surveys to identify the depth and physical characteristics of an infilled site formerly subject to sand mining for heavy mineral sands. We outline a fast non- invasive technique that allows large areas of coastal dunes to be imaged for the purposes of delineating past land uses. The technique is likely to be particularly applicable to developing coasts where the historical record is incomplete or fragmentary or there has been a history of poorly constrained or illegal sand mining.