Sea Level Rise Seminar, 2021-11-16: Philip Orton

Sea Level Rise Seminar, 2021-11-16

Speaker: Philip Orton
Title: Attribution of rising coastal floods to sea level rise and estuary urbanization

Abstract: Coastal flooding is one of the most dangerous and damaging natural hazards that societies face, and coastal development and climate change are causing a dramatic rise in vulnerability. It is widely established that sea level rise is raising extreme event floods and amplifying the frequency of nuisance floods worldwide. A compounding factor is that since the 19th century, estuary channels have typically been deepened and widened by a factor of two or three, inlets have been deepened and streamlined, and a large proportion of wetlands have been filled over and replaced with neighborhoods. These geomorphic changes increase flood hazards by reducing natural resistance to storm surge and tides.
In this presentation, I will report on recent research where we seek to separately quantify coastal flooding contributions from sea level rise and from estuary urbanization. First, I will present statistical modeling research that uses tidal harmonic analysis to demonstrate how changing tides, usually due to estuary urbanization practices such as dredging and landfill, have increased US nuisance flooding by about 20%. Second, I will demonstrate examples of the hydrodynamic modeling approach for attribution. Anthropogenic sea level rise alone caused an additional $8B in damages and 70000 affected population during Hurricane Sandy. Extending similar modeling to tidal nuisance flooding, I will present results for a 2020 simulation of Jamaica Bay (New York) floods and attribution to both landscape and sea level change. Of 15 minor floods in 2020, there would only have been 2 without geomorphic change and 1 without sea level rise since the 1870s. Using these simulation data, a clear fingerprint is identified in the frequency dependence of water level transfer into the bay that differentiates landscape and sea-level change effects, providing potential clues toward statistical attribution methods for separating sea level and geomorphic change effects from global tide gauge datasets.

Видео Sea Level Rise Seminar, 2021-11-16: Philip Orton канала NASA Goddard Institute for Space Studies