<p dir="ltr">Barrier islands can protect the mainland from flooding during storms through reduction of storm surge and dissipation of storm generated wave energy. However, the protective capability is reduced when barrier islands breach and a direct hydrodynamic connection between the water bodies on both sides of the barrier island is established. Breaching of barrier islands during large storm events is complicated, involving nonlinear processes that connect water, sediment transport, dune height, and island width among other factors. In order to assess how barrier island breaching impacts flooding on the mainland, we used a statistical approach to analyze the sensitivity of mainland storm-surge to barrier island breaching by randomizing the location, time, and extent of a breach event. We created a framework that allows breaching to develop during the course of a simulation and imposes a breach in an approximation of a Gaussian bell-curve that deepens over time. We show that simulating a storm event and varying the size, location, and number of breaches in the barrier island that mainland storm surge and horizontal inundation is affected by breaching; total inundation has a logarithmic relationship with total breach area which tapers off after the entire island is removed. Breach location is also an important predictor of inundation and bay surge. The insights we've gleaned from this study can help prepare shoreline communities for the differing ways that breaching affects the mainland coastline. Understanding which mainland locations are vulnerable to breaching, planners and coastal engineers can design interventions to reduce the likelihood of a breach occurring in areas adjacent to high flood risk.</p>
Publisher
University Libraries, Virginia TechCorresponding Author Name
Catherine R JeffriesFiles/Folders in Dataset and Description
ROOT (BarrierBreach_Ensemble_v1.0)
gauges_ensemble.nc
Core dataset. NetCDF [time × gauge × simulation] of water_level_* (meters above NAVD88).
Includes per-simulation categories (width, depth, width+depth, location, no_breach) and summaries across simulations:
mean, median, 5th and 95th percentiles. Time is seconds from landfall; also includes hours-from-landfall for plotting.
Coordinates include simulation_name (original identifiers), gauge_label (84, 82, 45, 133, 11, 119), and gauge_region (west, central, east).
no_breach_fgmax.nc
Fixed-grid maximum water level for the baseline no_breach simulation.
Variables: eta, h, B (meters above NAVD88) and latitude/longitude (degrees, WGS84).
Maximum across all timesteps (no time variable).
histogram_archive.nc
Precomputed distributions/summary products separated by breach simulation category (Width, Depth, Width&Depth, East, West, Locations).
Values are meters above NAVD88; used to generate manuscript figures.
histogram_archive_long.csv
Long-format table for figure histograms.
Columns: figure (e.g., Fig5), scope (point=gauge max, regional=regional max), region (west/central/east),
kind (category: width/depth/dw/loc/etc.), source_name (simulation identifier), value (meters above NAVD88).
Each row is a maximum water level for one simulation and scope; histograms aggregate across simulations.
gauge85310.txt
Model output for a test simulation around Sandy Hook, NJ, used to validate against NOAA Gauge 8531680.
Columns: time_seconds_from_landfall, eta_m_NAVD88. Tides excluded (surge-only).
Landfall reference near Bellport, NY (time=0; seconds used as the time basis).
metadata/
m_gauges.csv
Gauge metadata (e.g., IDs, coordinates, labels used in plotting).
ocean_gauges.csv
Ocean gauge list and metadata.
plotting_gauges_locs.csv
Mapping of plotting labels to gauge IDs/locations used in figure scripts.
wet_cells/
location_wet_cells.csv
Wet-cell metrics for “loc” simulations, computed relative to the no_breach baseline.
Columns include: wet_cell_count (additional wet cells vs baseline), diff_topo (difference from total topographic wet/dry counts),
diff_no_breach (difference in wet-cell count vs baseline), num_breaches (integer),
mean_depth (m), mean_distance (m; breach width), mean_breach_area (m^2), total_breach_area (m^2),
inundation_per_breach (m^2 = wet_cell_count × 18 m × 18 m).
width_depth_wet_cells.csv
Same metrics for combined width+depth (“dw”) simulations (relative to no_breach).
depth_wet_cells.csv
Same metrics for depth (“d”) simulations (relative to no_breach).
width_wet_cells.csv
Same metrics for width (“w”) simulations (relative to no_breach).
west_wet_cells.csv
Regional wet-cell summary (west), relative to no_breach.
east_wet_cells.csv
Regional wet-cell summary (east), relative to no_breach.
mesh_specs/
OriginalBreaches_mesh.dat
Baseline polygon set (GMT closed polygons, WGS84) used to illustrate breach footprints.
w_.dat
GMT closed polygons (WGS84) for width-only breach variants; polygons encode breach locations with associated depths for plotting.
d_.dat
GMT closed polygons (WGS84) for depth-only breach variants; polygons encode breach locations with associated depths for plotting.
dw_.dat
GMT closed polygons (WGS84) for combined width+depth breach variants; polygons encode breach locations with associated depths for plotting.
loc_.dat
GMT closed polygons (WGS84) for breach-location variants; polygons encode breach locations with associated depths for plotting.
east_.dat / west_.dat
Region-specific GMT polygon files (WGS84) illustrating breach footprints and depths.
map_figure_data/
README.md
Notes on how the map data were prepared and how to load them.
metadata.json
Machine-readable metadata about figure datasets and selections.
metadata.yaml
YAML version of the same metadata.
load_data_example.py
Example Python script to open and visualize the map NetCDF files.
figure8/
max_surge.nc
Maximum sea surface height across the selected simulation group used in Figure 8.
Variables: latitude, longitude (WGS84), eta (meters above MSL). Non-positive eta values are omitted/masked; no time variable.
mean_surge.nc
Mean sea surface height across the selected simulation group (Figure 8); same structure/units as max_surge.nc.
min_surge.nc
Minimum sea surface height across the selected simulation group (Figure 8); same structure/units as max_surge.nc.
no_breach.nc
Baseline no-breach sea surface height (Figure 8); same structure/units as max_surge.nc.
figure9/
scenario_central.nc
Maximum sea surface height for the “central” scenario group (Figure 9); variables: lat, lon (WGS84), eta (meters above MSL); no time variable; non-positive eta omitted/masked.
scenario_w.nc
Maximum sea surface height for the “west” scenario group (Figure 9); same structure/units as scenario_central.nc.
figure10/
east_max.nc
Maximum sea surface height for the “east” scenario group (Figure 10); variables: lat, lon (WGS84), eta (meters above MSL); no time variable; non-positive eta omitted/masked.
west_max.nc
Maximum sea surface height for the “west” scenario group (Figure 10); same structure/units as east_max.nc.
NOTE ON VERTICAL DATUMS
Core gauge/summary products (e.g., gauges_ensemble.nc, histograms) use NAVD88.
Map figure products in map_figure_data use MSL. Users should not mix MSL and NAVD88 values without an appropriate datum conversion.
