wind_rose: Summarize a time series of wind fields into a wind rose

In matthewkling/windscape: Landscape connectivity by wind

Summarize a time series of wind fields into a wind rose

Description

This function converts a wind_field_ts into a wind_rose object summarizing the distribution of wind speed and direction observations in each grid cell. The result is a set of eight raster layers giving the average wind conductance toward each of a cell's 'queen' neighbors.

Usage

wind_rose(x, trans = 1, ...)

Arguments

x	Data set of class 'wind_series'.
trans	Either a function, or a positive number indicating the power to raise windspeeds to; see details.
...	Additional arguments passed to ‘terra::app', e.g. ’filename'.

Details

The 'trans' parameter defines the transformation function used to convert wind speed into conductance. If a numeric value is supplied, the function speed^trans is used. A value of trans = 0 will ignore speed, assigning weights based on direction only; trans = 1 assumes conductance is proportional to windspeed, trans = 2 assumes it's proportional to aerodynamic drag, and trans = 3 assumes it's proportional to force. Any intermediate value can also be used. Any function that transforms a numeric vector can also be supplied; for example, to model seed dispersal for a species that only releases seeds when winds exceed 10 m/s, we could specify a threshold function 'trans = function(x)x[x < 10] <- 0; return(x)'.

Value

A wind_rose object. This is an 8-layer raster stack, where each layer is wind conductance from the focal cell to one of its neighbors (clockwise starting in the SW). If input windspeeds are in m/s and 'trans = 1', values are in (1 / hours)

matthewkling/windscape documentation built on Sept. 26, 2024, 4:22 p.m.