METADATA FOR "sedimet_patches.csv"
Written by Chloe Ross, last updated Dec 11, 2025

PROCESSING:
	- Differenced survey DEMs to create an elevation change raster
	- Set colour ramp for elevation change raster to +/- 10m, then hand mapped patches
	- Created volume change raster by multiplying the elevation change raster by DEM cell area
	- Calculated zonal statistics for mapped patch area for both the elevation change raster, as well as volume change raster
	- Extracted points along polygon borders of mapped patches, then calculated distance of each point to nearest river metre point
	- Identified the max, min, and mean river metre identified for each patch (gives the upstream, downstream, and middle of patch along river centreline)
	- Calculated the total survey area for each canyon over each era as the number of cells in the DEM for that date multiplied by the cell area.

COLUMN NAMES AND MEANINGS:
	id_all: unique id for all patches over all eras
	canyon: canyon that patch was mapped within
	magnitude: whether change was positive ("pos") or negative ("neg")
	era: timestep between surveys, era 0 is 2204-2111, 1 is 2208-2204, and 2 is 2308-2208.
	id_era: unique id for patches within each era
	count: number of cells within mapped patch
	area: area of cells within mapped area (not the area of the polygon, but the cell count within the polygon multiplied by cell area)
	total_survey_area: area of the whole survey DEM (i.e. region of canyon with data collected) in which the patch was mapped
	v_sum: sum of values within each patch for volume change raster (i.e. total volume of change for that patch)
	e_sum: sum of values within each patch for elevation change
	e_mean: mean elevation value within patch
	e_median: median elevation value within patch
	e_stdev: standard deviation of elevation values within patch
	min_RM: minimum RM identified for points along border of that patch
	max_RM: max RM identified for points along border of that patch
	medan_RM: median RM identified for points along border of that patch
	min_RK: minimum RK identified for points along border of that patch
	max_RK: max RK identified for points along border of that patch
	medan_RK: median RK identified for points along border of that patch