Workflow Narrative

Corridor Mapping and Route Planning

Problem It Solves

What is the terrain-optimal route for this linear infrastructure, and what alternative corridor band exists within an acceptable cost margin?

Who It Is For

Infrastructure planners, environmental consultants, and natural resource agencies assessing route options for roads, pipelines, or utility lines.

Primary User

Forestry companies, energy utilities, and environmental regulatory consultancies evaluating new linear infrastructure corridors.

What It Does

Builds a terrain impedance cost surface from DEM-derived slope and roughness.
Finds the least-cost path between two user-specified endpoints using Dijkstra accumulation.
Delineates a corridor suitability band of near-optimal alternative routes.
Supports polygon exclusion zones (steep terrain, protected areas, existing infrastructure).

How It Works

Computes per-cell cost from slope (and optionally local roughness) normalised to [0, 1].
Runs Dijkstra from both start and end to accumulate cost surfaces.
Least-cost path traced back from end → start through predecessor pointers.
Corridor band: cells where `acc_from_start + acc_from_end ≤ optimal_cost × (1 + tolerance)`.
Indicative formula: cost ~= w_slope × slope_norm + w_rough × roughness_norm (profile-controlled weights).

Why It Wins

Compared with OSS least-cost building blocks (`cost_distance` + `cost_pathway` + `cost_allocation`), this tool is an end-to-end siting workflow: it derives the terrain cost surface from the DEM, computes the optimal route, delineates near-optimal corridor alternatives, and packages decision-ready outputs in one run.
Why it wins vs OSS least-cost tools:
Requires fewer analyst preparation steps (no separate friction-raster engineering pipeline required).
Returns vector route geometry with engineering-friendly attributes, not just a path raster.
Produces a corridor suitability band for option-space review, not only a single least-cost trace.
Supports polygon exclusion constraints directly in the routing workflow.
Emits a machine-readable summary contract for reproducible QA/reporting integration.

Typical Buying Trigger

A feasibility study needs a first-pass route alignment and suitability band for stakeholder review before field surveys. Cost profiles: - `slope_only` — slope-only impedance; fastest, suitable for quick screening. - `slope_roughness` — balanced slope + roughness blend (default); recommended for road and pipeline siting. - `conservative` — equal slope/roughness weighting; preferred for sensitive terrain or pipelines.

Inputs

Parameter	Optional	Description
dem	no	Input DEM raster path.
start_features	no	Start feature vector path (point or polygon).
end_features	no	End feature vector path (point or polygon).
constraints	yes	Optional exclusion zone vector path (polygons to avoid).
cost_profile	yes	Cost weighting profile: `slope_only` \| `slope_roughness` \| `conservative`. Default: `slope_roughness`.
terminal_anchor_strategy	yes	Polygon terminal anchor mode: `mixed` \| `centroid_only` \| `boundary_only`. Default: `mixed`.
corridor_tolerance	yes	Fraction above optimal cost included in corridor suitability band. Default: `0.15`.
output_prefix	yes	Output prefix for generated artifacts.

Outputs

Parameter	Type	Description
cost_surface	GeoTIFF	Normalized terrain impedance surface [0-1].
accumulated_cost	GeoTIFF	Dijkstra accumulated cost from selected start anchor.
optimal_route	GeoPackage	Least-cost route LineString with route metrics.
corridor_suitability	GeoTIFF	Binary suitability band (`1` = within tolerance).
summary	JSON	Summary contract with metrics, selected anchors, and harmonization metadata.
html_report	HTML	Human-readable customer-facing report generated from the summary contract for stakeholder review and QA traceability.

Python Example

import whitebox_workflows as wbw

wbe = wbw.WbEnvironment(include_pro=True, tier="pro")

cost, acc_cost, route, suitability, summary = wbe.corridor_mapping_intelligence(
    dem="data/dem.tif",
    start_features="data/start_access_points.gpkg",
    end_features="data/forest_block_targets.gpkg",
    cost_profile="slope_roughness",
    terminal_anchor_strategy="mixed",
    corridor_tolerance=0.15,
    output_prefix="output/access_road",
)

print(route)       # path to optimal_route.gpkg
print(suitability) # path to corridor suitability raster
print(summary)     # path to summary JSON

License Notice

Use of this function requires a license for Whitebox Workflows Professional (WbW-Pro). Please visit www.whiteboxgeo.com to purchase a license.

Project Links

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