prep_reach_dist: Calculate the distance from a well to each reach within a stream network. This function splits a polyline stream network up into a series of evenly spaced points and calculates the distance from each of those points to a well.

Description

Calculate the distance from a well to each reach within a stream network. This function splits a polyline stream network up into a series of evenly spaced points and calculates the distance from each of those points to a well.

Usage

prep_reach_dist(
  wel_lon,
  wel_lat,
  stream_shp,
  reach_id,
  stream_pt_spacing,
  buffer_width = 0.1,
  nseed = 1
)

Value

A data frame with four columns:

reach: a grouping variable with the name of each stream reach
dist: distance of a point on that stream reach to the well of interest
lat: latitude of that point
lon: longitude of that point

This data frame can be plugged directly into apportion_inverse, apportion_polygon (if latlon=T), or apportion_web

Arguments

wel_lon: longitude of well
wel_lat: latitude of well
stream_shp: shapefile of stream reaches
reach_id: string indicating name of column in stream_shp that
stream_pt_spacing: distance between points used for sampling each stream reach. The actual distance between points will be close to this (but not necessarily exact) due to sampling rounding error. The finer spacing you use, the more accurate your results will be but the function will run slower and use more memory.
buffer_width: width of buffer around stream used to match points with polylines
nseed: seed for random number generator (this is used to convert stream polylines to points)

Examples

Run this code

rdll <- prep_reach_dist(wel_lon = 295500, wel_lat = 4783200,
   stream_shp = stream_lines, reach_id = "reach", stream_pt_spacing = 1)
head(rdll)

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