fractopo¶

fractopo is a Python module that contains tools for validating and analysing lineament and fracture trace maps (fracture networks).

$Overview of fractopo$

Overview of fractopo¶

Full documentation¶

Documentation is hosted on Read the Docs:
- Documentation

Installation¶

pip and poetry installation only supported for linux and MacOS based operating systems. For Windows install using (ana)conda.

For pip and poetry: Omit –dev or [dev] for regular installation. Keep if you want to test/develop or otherwise install all development python dependencies.

Conda¶

Only supported installation method for Windows!

# Create new environment for fractopo (recommended)
conda env create fractopo-env
conda activate fractopo-env
# Available on conda-forge channel
conda install -c conda-forge fractopo

Pip¶

The module is on PyPI.

# Non-development installation
pip install fractopo

Or locally for development:

git clone https://github.com/nialov/fractopo
cd fractopo
# Omit [dev] from end if you do not want installation for development
pip install --editable .[dev]

poetry¶

For usage:

poetry add fractopo

For development:

git clone https://github.com/nialov/fractopo --depth 1
cd fractopo
poetry install

Usage¶

See Full documentation for usage guidance and examples.

Input data¶

Reading and writing spatial filetypes is done in geopandas and you should see geopandas documentation for more advanced read-write use cases:

https://geopandas.org/

Simple example with trace and area data in GeoPackages:

import geopandas as gpd

# Trace data is in a file `traces.gpkg` in current working directory
# Area data is in a file `areas.gpkg` in current working directory
trace_data = gpd.read_file("traces.gpkg")
area_data = gpd.read_file("areas.gpkg")

Trace validation¶

Trace and target area data can be validated for further analysis with a Validation object.

from fractopo import Validation

validation = Validation(
    trace_data,
    area_data,
    name="mytraces",
    allow_fix=True,
)

# Validation is done explicitly with `run_validation` method
validated_trace_data = validation.run_validation()

Trace validation is also accessible as a command-line script, tracevalidate which is more straightforward to use than through Python calls.

tracevalidate always requires the target area that delineates trace data.

# Get full up-to-date script help

tracevalidate --help

# Basic usage:
# --fix is recommended due to automatic fixing being very minor in effect
# currently
# --output can be omitted. By default the same spatial filetype
# as the input is used and the output is saved as e.g.
# /path/to/validated/trace_data_validated.shp
# i.e. a new folder is created (or used) for validated data
# --summary can be given to print out summary data of validation
# i.e. error types and error counts

tracevalidate /path/to/trace_data.shp /path/to/target_area.shp --fix --output /path/to/output_data.shp

# Or with automatic saving to validated/ directory

tracevalidate /path/to/trace_data.shp /path/to/target_area.shp --fix --summary

Geometric and topological trace network analysis¶

Trace and target area data (GeoDataFrames) are passed into a Network object which has properties and functions for returning and visualizing different parameters and attributes of trace data.

from fractopo import Network

# Initialize Network object and determine the topological branches and nodes
network = Network(
    trace_data,
    area_data,
    # Give the Network a name!
    name="mynetwork",
    # Specify whether to determine topological branches and nodes
    # (Required for almost all analysis)
    determine_branches_nodes=True,
    # Specify the snapping distance threshold to define when traces are
    # snapped to each other
    snap_threshold=0.001,
    # If the target area used in digitization is a circle, the knowledge can
    # be used in some analysis
    circular_target_area=True,
    # Analysis on traces can be done for the full inputted dataset or the
    # traces can be cropped to the target area before analysis (cropping
    # recommended)
    truncate_traces=True,
)

# Properties are easily accessible
# e.g.
network.branch_counts
network.node_counts

# Plotting is done by plot_ -prefixed methods
network.plot_trace_lengths()

Development status¶

Breaking changes are possible and expected.
Critical issues:
- Trace validation should be refactored at some point.
  - Though keeping in mind that the current implementation works well.
- snap_traces in branch and node determination is not perfect. Some edge cases cause artifacts which only sometimes are recognized as error branches. However these cases are very rare.
  - Reinforces that some amount of responsibility is always in the hands of the digitizer.
  - Issue mostly avoided when using a snap_threshold of 0.001

Contents¶

Trace data must be validated using fractopo validation functionality before analysis. The topological analysis of lineament & fracture traces implemented in fractopo will not tolerate uncertainty related to the topological abutting and snapping relationships between traces. Therefore the trace validation is recommended before all analysis using Network.

Validating trace data

See above links for:

Basic trace data validation workflows
Examples of validation error types

For trace validation also see above guide on tracevalidate command-line tool. After trace data validation, Network analysis can be conducted.

Analyzing trace data

See above links for:

Workflow of analyzing trace data with visualizations of geometric topological network characteristics.
Example scripts showcasing different analysis and plotting functionality implemented in fractopo.
Notebook - Fractopo – KB11 Fracture Network Analysis is especially recommended.

Module documentation for developers

fractopo package