GeoProfiler v0.3 – Help

Plugin authors: M. Alberti, M. Zanieri
Concept: M. Zanieri
Implementation: M. Alberti

Overview

GeoProfiler helps you build geological profiles by integrating topography and georeferenced geological data (points, attitudes, lines, polygons) into a reproducible workflow.

It is part of qgSurf and evolves from the standalone qProf plugin, with a largely rewritten architecture.

Quickstart (2 minutes)

If you just want to create a geological profile quickly:

1. Create a topographic profile

Digitize a trace or load a line layer
Select a DEM
Run → Generate 3D profile

This creates a 3D line layer stored in a GeoPackage.

2. Select the working profile

Load the 3D line layer into QGIS
Run → Choose working 3D profiles layer

3. Add geological data

Points → Point projections
Attitudes → Attitude projections
Faults → Line intersections
Outcrops → Polygon intersections

4. Plot

Run → Plot

You now have a geological profile.

5. (Optional) Save your work

Export geoprofile
Save graphical parameters

Reload later with Import geoprofile.

Minimal requirements

A DEM
A line (or a digitized trace)

Quick Example (field use)

Digitize a profile across an Apennine ridge, select a DEM, and generate the 3D profile. Then project bedding attitudes and intersect mapped fault traces. Plot the profile to visualize the relationships between stratification and tectonic structures.

Workflow Overview (visual)

[Trace (2D/3D)]        [DEM]
        │                │
        └──────┬─────────┘
               ▼
     Generate 3D profile
               │
               ▼
     [3D profile layer]
               │
               ▼
 Choose working profile
               │
               ▼
   Add geological data
   ├─ Points (projection)
   ├─ Attitudes (projection)
   ├─ Lines (intersection)
   └─ Polygons (intersection)
               │
               ▼
            Plot
               │
       ┌───────┴────────┐
       ▼                ▼
Export geoprofile   Save style
       │                │
       └──────┬─────────┘
              ▼
       Import geoprofile

Core Concept

GeoProfiler is built around two geometric elements:

Topographic line → the 3D profile trace sampled from the DEM
Profile plane → a vertical plane orthogonal to the profile trace

Data behavior

Projected data
- Points
- Geological attitudes
projected onto the profile plane
Intersecting data
- Lines (faults)
- Polygons (outcrops)
intersect the topographic line

Mental Model (important)

All outputs depend only on:

profile geometry
geological data
graphical parameters

The plot is a pure result, not stored.

1. Creating Topographic Profiles

Profiles are stored as 3D line layers in a GeoPackage.

Define the trace

Load from an existing layer
Or digitize in canvas

Define elevation

Select DEM

Generate profile

Creates 3D line(s)

Parallel profiles

Number must be odd (1, 3, 5, …)
Generated symmetrically around the base trace

2. Working Profile Layer

Load the 3D line layer into QGIS and select:

Choose working 3D profiles layer

This defines the reference geometry for all operations.

Redefining the base 3D profile (new line source, DEM, digitized trace, or project reload) clears any previously defined point/attitude projections and line/polygon intersections, since they were computed against the profile just discarded. Redefine the geological data stages afterwards.

3. Geological Data Integration

Each stage below (points, attitudes, lines, polygons) runs its own projection/intersection immediately once its dialog is confirmed - there is no separate "create/apply" step: define a stage, and its result is computed and added to the geoprofile right away, ready to be re-plotted.

3.1 Point projections

Inputs:

Point layer
Elevation field
Maximum distance from profile

3.2 Attitude projections

Inputs:

Point layer
Dip direction (or strike, RHR)
Dip angle

Output:

Marker + segment representing plane–profile intersection

3.3 Line intersections

Input: line layer
Output: points along the topographic profile

3.4 Polygon intersections

Input: polygon layer
Output: categorized intersections along the profile

4. Graphical Parameters

Controls the appearance of the plot:

Figure size
Vertical exaggeration
Elevation limits
Colors, markers, labels

Persistence

Save parameters
Reload parameters

Polygon categories must match when reloading saved parameters.

5. Plot

Run:

Plot

Uses default parameters if none are defined
Automatically reflects any change in data or graphical parameters

6. Export and Import (Reproducibility)

Key idea

Data and visualization are decoupled.

Export stores data
Graphical parameters are stored separately

Export geoprofile

Use:

Export geoprofile

This saves:

projected points
projected attitudes
line intersections
polygon intersections

Into a database file: SQLite by default (.sqlite/.db), or GeoPackage (.gpkg) if preferred.

Import geoprofile

Use:

Import geoprofile

This allows you to:

reload previously computed data
restore a working session
re-plot without recomputing

Why this matters

Reproducible workflows
Reusable datasets
Shareable results
Independent styling

7. Current Limitations

No GPX input
No slope calculation

Design Philosophy

GeoProfiler is designed to be:

Reproducible
Modular
Flexible (supports non-linear and parallel profiles)