Beaching Probability Index (BPI): Frequently Asked Questions
This length of time was based on a very rough guess of how long carcasses last at sea as well as some test runs where beyond 8 days, the ocean conditions (weather) often change and so the BPI starts to become less meaningful for local coastal conditions. Also, to travel across the shelf in steady conditions, it usually takes 8 days or so to travel 60 nm.
If the strip of land is so narrow that its width is less than the model grid, then the model likely won't simulate these areas properly, which is a well-known problem with all numerical models. The particles seemingly can cross those barrier islands and won't accumulate on the offshore side of them. These needs to be taken into account when comparing the BPI to stranding numbers.
Color-coded scatter plot is used to display the distribution of BPI with bigger dots representing larger values. The BPI legend just shows the representative values (1, 10, 100, 1000, 10000) of the BPI. A base-10 log scale is used for BPI values and the log10 scale values determine the size and color of the dots. The actual values in the map are ranges, not a single value.
If a user repeatedly wants the same regions defined, then a local file defining the regions can be imported. The format of this .csv or .txt file is as follows:
Header: region,minLon,maxLon,minLat,maxLat,numPts,lon1,lat1,lon2,lat2,...,lonN,latN,
Row 1: myRegion1,-90,-88,29,31,4,-90,29,-90,31,-88,31,-88,29,
Row 2: myRegion2,-87,-85,29,31,4,-87,29,-87,31,-85,31,-85,29,
:
where “region” is the name of the new region,
“minLon” is the minimum longitude of the region, “maxLon” is the maximum longitude of the region,
“minLat” is the minimum latitude of the region, “maxLat” is the maximum latitude of the region,
“numPts” is the number of points of the region,
“lon1,lat1,lon2,lat2,...,lonN,latN,” are the longitude and latitude values of the points either in clockwise or counterclockwise direction.
