Sea-level rise will increase the area covered by hurricane storm surges in coastal zones. This research assesses how patterns
of vulnerability to storm-surge flooding could change in Hampton Roads, Virginia as a result of sea-level rise. Physical exposure
to storm-surge flooding is mapped for all categories of hurricane, both for present sea level and for future sea-level rise.
The locations of vulnerable sub-populations are determined through an analysis and mapping of socioeconomic characteristics
commonly associated with vulnerability to environmental hazards and are compared to the flood-risk exposure zones. Scenarios
are also developed that address uncertainties regarding future population growth and distribution. The results show that hurricane
storm surge presents a significant hazard to Hampton Roads today, especially to the most vulnerable inhabitants of the region.
In addition, future sea-level rise, population growth, and poorly planned development will increase the risk of storm-surge
flooding, especially for vulnerable people, thus suggesting that planning should steer development away from low-lying coastal
and near-coastal zones. 相似文献
Regional-scale washover deposits along the Florida Gulf and Atlantic coasts induced by multiple hurricanes in 2004 and 2005 were studied through coring, trenching, ground-penetrating radar imaging, aerial photography, and prestorm and poststorm beach-profile surveys. Erosional and depositional characteristics in different barrier-island sub-environments, including dune field, interior wetland and back-barrier bay were examined. Over the eroded dune fields, the washover deposits are characterized by an extensive horizontal basal erosional surface truncating the old dune deposits and horizontal to slightly landward-dipping stratification. Over the marshes in the barrier-island interior, the washover deposits are characterized by steep tabular bedding, with no erosion at the bottom. Overwash into the back-barrier bay produced the thickest deposits characterized by steep, prograding sigmoidal bedding. No significant erosional feature was observed at the bottom. Washover deposits within the dense interior mangrove swamp demonstrate both normal and reversed graded bedding. The washover deposits caused by hurricanes Frances (2004) and Jeanne (2004) along the southern Florida Atlantic coast barrier islands are substantially different from those along the northern Florida barrier islands caused by Ivan (2004) and Dennis (2005) in terms of regional extension, erosional features and sedimentary structures. These differences are controlled by different overall barrier-island morphology, vegetation type and density, and sediment properties. The homogeneity of sediment along the northern Florida coast makes distinguishing between washover deposits from Ivan and Dennis difficult. In contrast, along the Atlantic coast barrier islands, the two overwash events, as demonstrated by two phases of graded bedding of the bimodal sediments, are easily distinguishable. 相似文献
Airborne bathymetric LIDAR observations along the Florida panhandle after Hurricane Dennis (2005) show the first unequivocal observations of surf-zone sand wave trains.
These are found in depths of 5m along the trough of the hurricane bar, where hindcasts show strong longshore currents only during severe storms. The waves extend over tens of kilometers of coast after Dennis but are absent from the same area in four other datasets. Observed wavelength to water depth ratios are comparable to river dunes and tidal sand waves but height to depth ratios are smaller, with the largest wave heights around 0.1 times the water depth. The sand wave generation mechanism is hypothesized to be from wind-and-wave-induced longshore currents, which were hindcast to be large during Dennis, with destruction from water wave orbital velocities. 相似文献
Consideration of climate-related impacts on coasts is important to ensure readiness for disaster response. Local risk of storm surge and strong winds from hurricanes affecting Galveston, Texas, is quantified using a bivariate copula model fit to observed data. The model uses a two-dimensional Archimedean copula. Parametric uncertainty (5th and 95th percentiles) is quantified using a Monte Carlo procedure. The annual probability of a hurricane producing winds of at least 50 ms?1 and a surge of at least 4 m is 1.7 percent with a 95 percent confidence interval of (1.33, 1.78) percent. The methodology can be extended to include inland flooding and can be applied elsewhere with available information. 相似文献
The rapid appearance of Ramicrusta spp. is described and analyzed from 40 permanent monitoring coral reef stations in Puerto Rico. Before 2016, Ramicrusta had not been observed from any of the reef monitoring stations. By 2018, it was present at 76% of all the monitoring stations. Ramicrusta was the dominant substrata type at all of the shallow reef sites sampled on the east coast (e.g., Fajardo, Culebra, and Vieques), reaching a cover (±SE) as high as 63.0 ± 5.8%. The spread of Ramicrusta occurred at the expense of historically resilient living benthic elements, such as turf algae. Since its detection in 2016, colonization of hard substrata by Ramicrusta remained constant, with the exception of two shallow reefs in Fajardo and Culebra, where the cover was significantly reduced by the scouring and or abrasive effects of two major hurricanes. The ecological implications of Ramicrusta prevalence on Puerto Rican reefs remain unclear; however, increasing herbivory might be a useful mitigation tool in the reduction of Ramicrusta abundance on coral reefs. 相似文献
A wind speed retrieval algorithm was developed using 6 and 10 GHz h-pol (6H and 10H) data of the Advanced Microwave Scanning
Radiometer (AMSR) aboard the Advanced Earth Observation Satellite-II (ADEOS-II) and AMSR-E aboard AQUA, for the purpose of
retrieving wind speed inside rainstorms, primarily hurricanes and typhoons. The h-pol was used rather than the v-pol, because
the brightness temperature sensitivity to the ocean wind at h-pol is larger than v-pol. The microwave emission change of 6H
and 10H corresponding to ocean wind was evaluated in no-rain areas by combining AMSR and SeaWinds data aboard the ADEOS-II
(SeaWinds was NASA’s scatterometer), and it was found that the ratio of the two 6H to 10H increments due to ocean wind is
0.9. Assuming that this result also holds with higher wind speeds and under rainy conditions, the brightness temperatures
at 6H and 10H were simulated using a microwave radiative transfer model. A parameter W6 (unit; Kelvin) was then defined, representing
an increment at 6H due to ocean wind. W6 is applicable to rainy areas, and to all ranges of sea surface temperature. W6 was
compared with wind speed reported by the National Hurricanes Center for several hurricanes in the Western Atlantic Ocean during
three years (2002 to 2004). W6 averaged around centers of hurricanes was found to exhibit a sensitivity to wind speed, such
as increasing from 22 K to 65 K as the wind speed rose from 65 to 140 knots (33 to 72 m/s), and an empirical relationship
relating the averaged W6 to wind speed in hurricanes was derived. 相似文献