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Storm Impact (storm + impact)

Distribution by Scientific Domains

Earth and Environmental Science	75%

Selected Abstracts

Sensitivity of post-hurricane beach and dune recovery to event frequency

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 5 2009
Chris Houser
Abstract The recovery of Santa Rosa Island in northwest Florida is characterized following Hurricane Katrina (September 2005), which was preceded by Hurricanes Ivan (2004) and Dennis (2005). Beach and dune recovery were quantified to the east and west of Pensacola Beach through a comparison of LiDAR data collected immediately following Hurricane Katrina and in July 2006 after almost a year of recovery. East of Pensacola Beach (the Santa Rosa Unit), the shoreline retreated by an average of 64 m during the 2004,2005 hurricane season and recovered by an average of 19 m. To the west of Pensacola Beach (the Fort Pickens Unit), the shoreline retreated by an average of 30 m, and while no significant shoreface recovery was observed, the presence of vegetation on low-profile dunes promoted backshore accretion. It is found that beachface recovery in the Santa Rosa Unit and backshore accretion in the Fort Pickens Unit occurred at the widest sections of the island where the pre-storm profile volume had been relatively large and overwash penetration was at a minimum. The narrow sections of the island (between cuspate headlands) had a smaller profile volume before the storms, leading to greater overwash penetration and in some cases island breaching in both sections, which limited the volume of sediment available for shoreface recovery. The alongshore variation in recovery is not only related to the island width, but also the offshore bathymetry, height of the pre-storm dunes and the overwash penetration. If sufficient time is allowed for the return of vegetation and the recovery of the dunes, the variations in storm impact observed during Hurricane Ivan will be reinforced during subsequent storms. In this respect, the level of impact during subsequent storms and the ability of the island to recover will depend on the frequency of storm events. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Tropical storm impact in Central America

METEOROLOGICAL APPLICATIONS, Issue 1 2006
Sabino Palmieri
Abstract In this study of tropical storm impacts in Central America, the relationship between physical variables (available in ,real time') and damage is explored, and a simple tool for early approximate evaluation of the impact is developed. Land track and energy dissipation appear as the most interesting parameters that modulate the hurricane impact. Because of the difficulty of attaching a monetary estimate to the damage caused in a large number of cases (as is required in a statistical approach), an ,Impact Index' based on the logarithm of casualties is introduced. Thereafter, within a subset of events in which damage in monetary terms is known, a rough link between damage and the Impact Index is derived. Shortly after a new event, as soon as land track and energy dissipation are known, either by means of an empirical equation or using a contour graph, the Impact Index may be determined. Another empirical equation allows a rough estimate of damage in monetary units, but because this estimate is based on a limited number of cases, it must be treated with caution. The methodology is tested for a small set of independent cases. Vulnerability to tropical cyclones depends not only on natural factors but also on sociopolitical conditions. A coupled sociological and environmental approach is believed to be the best way to improve the early impact estimate methodology. Copyright © 2006 Royal Meteorological Society. [source]

Geostatistical interpolation of space,time rainfall on Tamshui River basin, Taiwan

HYDROLOGICAL PROCESSES, Issue 23 2007
Shin-Jen Cheng
Abstract Taiwan suffers from heavy storm rainfall during the typhoon season. This usually causes large river runoff, overland flow, erosion, landslides, debris flows, loss of power, etc. In order to evaluate storm impacts on the downstream basin, a real-time hydrological modelling is used to estimate potential hazard areas. This can be used as a decision-support system for the Emergency Response Center, National Fire Agency Ministry, to make ,real-time' responses and minimize possible damage to human life and property. This study used 34 observed events from 14 telemetered rain-gauges in the Tamshui River basin, Taiwan, to study the spatial,temporal characteristics of typhoon rainfall. In the study, regionalized theory and cross-semi-variograms were used to identify the spatial-temporal structure of typhoon rainfall. The power form and parameters of the cross-semi-variogram were derived through analysis of the observed data. In the end, cross-validation was used to evaluate the performance of the interpolated rainfall on the river basin. The results show the derived rainfall interpolator represents the observed events well, which indicates the rainfall interpolator can be used as a spatial-temporal rainfall input for real-time hydrological modelling. Copyright © 2007 John Wiley & Sons, Ltd. [source]