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Description

This function calculates the number of times a pixel has changed during the analysed period. It returns a raster with the number of changes as pixel value and a table containing the areal percentage of every pixel value (number of changes).

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Usage

acc_changes(path)

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Arguments

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path
character or list
The path for the Raster* directory or list of Raster* to be analysed.

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Value

Returns a list containing two objects:
  1. RasterLayer: A raster where each pixel value represents the number of times that pixel changed during the time series
  2. Table: A tibble with three columns:
    • PxValue: The pixel value (number of changes)
    • Qt: The quantity of pixels with that number of changes
    • Percent: The areal percentage of pixels with that number of changes

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Details

The function works by:
  1. Loading all raster layers from the specified path or list
  2. Comparing consecutive time steps to identify where changes occurred
  3. Summing the total number of changes for each pixel across all time intervals
  4. Computing summary statistics about the frequency of changes
This is useful for identifying areas of high turnover in land use/cover categories, which may indicate landscape instability or intensive land management.

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Examples

# Download the SaoLourencoBasin dataset
url <- "https://zenodo.org/record/3685230/files/SaoLourencoBasin.rda?download=1"
temp <- tempfile()
download.file(url, temp, mode = "wb")
load(temp)

# Calculate accumulated changes
result <- acc_changes(SaoLourencoBasin)

# Access the raster layer
changes_raster <- result[[1]]

# Access the summary table
changes_table <- result[[2]]
print(changes_table)

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See Also

  • summary_map() - Quantitative summary of a single categorical raster
  • summary_dir() - Summary of multiple raster parameters in a directory

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