Hillslopes and ridgelines

Hillslope process diagnostics from real landscapes (slope–area, gradient against curvature, E–R, hilltop–channel coupling) and ridgeline profiles from lsdtt-ridgeline-analysis. For the solver tests see Landscape evolution.

Hillslope charts

Each module docstring explains what the figure tests and how to read it; read it before quoting a result.

Function	Module	What it draws
plot_slope_area	charts.slope_area	The slope–area "boomerang" from slope + drainage-area rasters, with the binned median and the hillslope/channel rollover interval (binned_median, rollover_area).
plot_gradient_curvature	charts.gradient_curvature	Convexity vs gradient with the linear and Roering nonlinear flux-law predictions overlaid (after Roering, 2008).
plot_estar_rstar	charts.estar_rstar	Measured hilltop E–R against the Roering et al. (2007) steady relation, plus the R* residual panel; summarise gives per-group residual statistics.

# E*-R* figure + per-group residual summary CSV
pixi run lsdviz3-estar-rstar --metrics hilltop_metrics.csv --outdir demo_output/estar

Hilltop–channel coupling (lsdviz3-hilltop-coupling)

Hilltop/channel coupling (lsdtt-hillslope-channel-coupling output, loaded with io.hilltop_coupling.load_hilltop_outputs) has its own chart set in charts.hilltop_coupling: plot_traces_on_hillshade, plot_trace_outcomes, plot_ridgelines_and_sides, plot_length_distributions, plot_ridgeline_profiles, plot_looped_trace_profiles.

# hilltop coupling figure set from one output directory or <write_path>/<write_fname> stem
pixi run lsdviz3-hilltop-coupling --prefix path/to/run/run_stem --outdir demo_output/hilltop

Flags: --prefix --outdir [--dem --channels --max-traces --dpi].

Ridgeline profiles

Four commands plot ridgelines from lsdtt-ridgeline-analysis (its *_with_polyfit.csv profile tables). Each takes its settings either as flags or from a driver file: --driver file.txt, with one key: value per line, each key setting the flag of the same name (write_path sets --write-path); flags on the command line win. Each writes PNG, SVG and PDF into png/, svg/ and pdf/ under --write-path, named --write-name. --ridgeline-number picks the ridgeline (default 0), --reverse-ridgeline flips its direction, and --use-distance-range with --minimum-distance / --maximum-distance clips it.

Command	What it draws	Main inputs
lsdviz3-ridgeline-curvature	Ridge-crest elevation, moving-window detrending, maximal curvature and the Laplacian along one ridgeline	--ridgeline-profile-csv; --moving-window-sizes-pixels and --curvature-lambdas-m (four values each, default 25,49,99,149); --site-display-name
lsdviz3-ridgeline-summary	Triple divide junctions, a ridgeline series with its curvature barcode, and a map of the ridgeline	--ridgeline-profile-csv; --hillshade-raster-file (map); up to three --native-tdj-csv-N and --topological-tdj-csv-N (threshold read from the file name); --channel-network-vector-file, --paired-flowpaths-vector-file; --ridgeline-series, --highlighted-tdj-type, --highlighted-tdj-threshold
lsdviz3-ridgeline-spacing	Maximal-curvature zero-crossing spacing against polyfit scale beside slope–area, one row per site	--site NAME PROFILE_CSV SLOPE_AREA_CSV (repeat per site) or site_<N>_* driver entries with --site-count; --log-spacing, --spacing-y-max-m
lsdviz3-mdd-ridgeline	A main-drainage-divide ridgeline profile above the model's drainage-area image	--ridgeline-profile-csv (range-defined, with a maximum-curvature metric); --drainage-area-map-png (lsdtt-lem log₁₀ drainage area of the same grid); --model-name, --guide-interval