| Title: | Models Topographic Exposure to Hurricane Winds |
| Version: | 1.2 |
| Date: | 2024-11-09 |
| Description: | The EXPOS model uses a digital elevation model (DEM) to estimate exposed and protected areas for a given hurricane wind direction and inflection angle. The resulting topographic exposure maps can be combined with output from the HURRECON model to estimate hurricane wind damage across a region. For details on the original version of the EXPOS model written in 'Borland Pascal', see: Boose, Foster, and Fluet (1994) <doi:10.2307/2937142>, Boose, Chamberlin, and Foster (2001) <doi:10.1890/0012-9615(2001)071[0027:LARIOH]2.0.CO;2>, and Boose, Serrano, and Foster (2004) <doi:10.1890/02-4057>. |
| Depends: | R (≥ 4.0.0) |
| License: | GPL-3 |
| Encoding: | UTF-8 |
| Imports: | graphics, grDevices, terra, utils |
| Suggests: | knitr, qpdf, testthat (≥ 3.0.0), rmarkdown |
| URL: | https://github.com/expos-model/ExposR |
| BugReports: | https://github.com/expos-model/ExposR/issues |
| RoxygenNote: | 7.3.2 |
| VignetteBuilder: | knitr |
| Config/testthat/edition: | 3 |
| NeedsCompilation: | no |
| Packaged: | 2024-11-09 14:11:34 UTC; erb709 |
| Author: | Emery Boose [aut, cre], President and Fellows of Harvard College [cph] |
| Maintainer: | Emery Boose <boose@fas.harvard.edu> |
| Repository: | CRAN |
| Date/Publication: | 2024-11-09 15:50:22 UTC |
Modeling Functions
Description
expos_model uses a raster file of elevation values, a specified wind direction, and a specified inflection angle to create a raster file of wind exposure values (0 = missing data, 1 = protected, 2 = exposed). The user can specify if coordinates are lat/long; otherwise lat/long is assumed if X values are between -180 and 180 and Y values are between -90 and 90. If lat/long, horizontal and vertical units are assumed to be degrees and meters, respectively; otherwise horizontal and vertical units must be the same. Columns are assumed to be closely aligned with true North (0 degrees); if not, the map orientation (azimuth) must be specified in degrees. The name of the input file is assumed to be "dem.tif".
expos_damage uses output from the EXPOS and HURRECON models to create a raster of hurricane wind damage where topographic exposure at each location is determined by peak wind direction. If a location is protected, the enhanced Fujita scale rating from HURRECON is reduced by a specified amount. This function requires a hurricane file in GeoTiff format created by HURRECON, exposure files created by EXPOS for the eight cardinal wind directions (N, NE, E, etc), and a reprojection file in CSV format (reproject.csv) that contains lat/long coordinates in degrees for the lower left and upper right corners of the digital elevation model.
Usage
expos_model(
wind_direction,
inflection_angle,
lat_long = NULL,
orient = 0,
save = TRUE,
exp_path = NULL
)
expos_damage(
hurricane,
inflection_angle,
protect,
save = TRUE,
exp_path = NULL
)
Arguments
wind_direction |
wind direction (degrees) |
inflection_angle |
inflection angle (degrees) |
lat_long |
whether coordinate system is latitude/longitude |
orient |
map orientation (degrees) |
save |
whether to save results to file |
exp_path |
path for current set of model runs |
hurricane |
hurricane name (as it appears in tif file) |
protect |
how much to reduce damage in protected areas (number of Fujita scale ratings) |
Value
raster of modeled exposure values
raster of modeled wind damage values
Examples
exp_path <- system.file("", package="ExposR", mustWork=TRUE)
expos_model(wind_direction=135, inflection_angle=6, save=FALSE, exp_path=exp_path)
Plotting Functions
Description
expos_plot creates a plot of a raster file. The user can specify if coordinates are lat/long; otherwise lat/long is assumed if X values are between -180 and 180 and Y values are between -90 and 90. Optional arguments include plot title, horizontal units, vertical units, vector boundary files, and color palette.
Usage
expos_plot(
filename,
title = "",
lat_long = NULL,
h_units = "meters",
v_units = "meters",
vector = TRUE,
colormap = "default",
exp_path = NULL
)
Arguments
filename |
name of input raster file |
title |
plot title |
lat_long |
whether coordinate system is latitude/longitude |
h_units |
horizontal units |
v_units |
vertical units |
vector |
whether to display vectory boundary files |
colormap |
color palette |
exp_path |
path for current set of model runs |
Value
no return value
Utility Functions
Description
expos_set_path sets the path for the current set of model runs.
expos_get_path returns the current path for a set of model runs.
Usage
expos_set_path(exp_path)
expos_get_path()
Arguments
exp_path |
path for current model runs |
Value
no return value
current path
Summarizing Functions
Description
expos_summarize displays summary information for a specified raster file, including the number of rows and columns, spatial extent, cell height and width, and minimum and maximum value. The user can specify if coordinates are lat/long; otherwise lat/long is assumed if X values are between -180 and 180 and Y values are between -90 and 90.
Usage
expos_summarize(filename, lat_long = NULL, console = TRUE, exp_path = NULL)
Arguments
filename |
name of input raster file |
lat_long |
whether coordinate system is latitude/longitude |
console |
whether to display results in console |
exp_path |
path for current set of model runs |
Value
a string containing summary information