seabed_area: Calculate planimetric seabed area

Description Usage Arguments Value See Also Examples

Description

Calculate planimetric seabed area within polygons and depth strata in square kilometers.

Usage

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seabed_area(Bathy, Polys, depth_classes = c(-600, -1800))

Arguments

Bathy

bathymetry raster with the appropriate projection, such as this one. It is recommended to use a raster of higher resolution than SmallBathy, see load_Bathy.

Polys

polygon(s) within which the areas of depth strata are computed.

depth_classes

numeric vector of strata depths. for example, depth_classes=c(-600,-1000,-2000). If the values -600,-1800 are given within depth_classes, the computed area will be labelled as 'Fishable_area'.

Value

dataframe with the name of polygons in the first column and the area for each strata in the following columns. Note that polygon names are taken from the first column in the data of the input SpatialPolygonDataframe.

See Also

load_Bathy, SmallBathy, create_Polys, load_RBs.

Examples

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#Example 1: Compute fishable area in Research Blocks using the SmallBathy (not recommended)

RBs=load_RBs() 
RBs@data[,1]=RBs$GAR_Short_Label #Take the 'GAR_Short_Label' as polygon names
FishDepth=seabed_area(SmallBathy,RBs)
#View(FishDepth)

#Example 2: Compute various strata areas within user-generated polygons

MyPolys=create_Polys(PolyData,Densify=TRUE)
FishDepth=seabed_area(SmallBathy,MyPolys,depth_classes=c(0,-200,-600,-1800,-3000,-5000))
#View(FishDepth)

CCAMLRGIS documentation built on Sept. 8, 2021, 9:09 a.m.