Surface profiles, depth to water, and cross-sections

library(potentiomap)
data("synthetic_wells")
data("synthetic_transect")
p <- ps_make_points(synthetic_wells, "x", "y", "gw_elevation",
                    "well_id", "EPSG:26916")
head <- ps_interpolate(p, methods = "IDW", grid_res = 300)$IDW
land <- head * 0 + 185
line <- terra::vect(synthetic_transect, geom = "wkt", crs = "EPSG:26916")

depth <- ps_depth_to_water_surface(head, land, "potentiometric")
depth$summary

##     surface_type finite_cells negative_cells near_zero_cells minimum_depth
## 1 potentiometric          169              0               0      14.16812
##   maximum_depth                               label
## 1      20.47199 depth to the potentiometric surface

profile <- ps_surface_profile(line, list(head = head, land = land), n = 12)
head(profile$profile)

##      line_id             sample_id sample_index chainage        x       y
## X  line_0001 line_0001_sample_0001            1    0.000 500000.0 4640400
## X1 line_0001 line_0001_sample_0002            2  313.926 500264.1 4640570
## X2 line_0001 line_0001_sample_0003            3  627.852 500528.1 4640740
## X3 line_0001 line_0001_sample_0004            4  941.778 500792.2 4640909
## X4 line_0001 line_0001_sample_0005            5 1255.704 501056.3 4641079
## X5 line_0001 line_0001_sample_0006            6 1569.630 501320.3 4641249
##    spacing     head land
## X       NA 169.4180  185
## X1 313.926 169.5389  185
## X2 313.926 169.6194  185
## X3 313.926 169.6007  185
## X4 313.926 169.6114  185
## X5 313.926 169.5145  185

section <- ps_cross_section(line, head, land, step = 300,
                            vertical_exaggeration = 3)
section$summary

##   profile_samples retained_wells omitted_wells maximum_chainage
## 1              13              0             0         3452.903
##   vertical_exaggeration
## 1                     3

A confined potentiometric surface is not relabeled a water table. The cross-section does not invent hydrostratigraphy or represent a 3-D flow model.