Skip to main content

Weathering-mediated bedrock erosion

Summary: Tools for modeling the weathering-mediated erosion of bedrock. The focus is on environments with no soil or talus accumulation: for example, on steep bedrock channel walls. The current treatment is 1d only, and it assumes an exponentially decaying weakening profile with depth into the rock.

Graph of erosion rate vs weathering number

Abstract

Weathering is important not only on hillslopes, but also in bedrock river channels, where it weakens exposed rock and makes it more susceptible to mechanical erosion. Removal of surface rock modifies the weathering depth profile, which in turn modifies the rate of weathering. Here we study how this interaction acts to set a steady-state erosion rate.

We define rock weakness to be its propensity to erosion by particle impacts: experiments indicate such weakness is inversely proportional to tensile strength squared; they show how such weakening takes place through wetting/drying, freeze/thaw and thermal cycling at rates that diminish in a roughly exponential fashion with depth; as such, we equate weakening explicitly with weathering.

Two speeds control the erosion rate: (i) the speed at which weathering propagates into the rock ${\lambda} {\eta_0}$, where ${\eta_0}$ is the weathering rate of fresh rock and ${\lambda}$ is the e-folding depth; (ii) the baseline speed of erosion of fresh rock ${u}_0$. Model behavior is parameterized by the ratio of these two speeds at steady-state, and is defined here as the dimensionless weathering number ${\mathcal{W}}$.

For slow weathering relative to erosion, ${\mathcal{W}}<0.25$, they simply add and the erosion rate is ${\lambda}{\eta_0} + {u_0}$. However, for relatively fast weathering, ${\mathcal{W}}>2.5$, the predicted behavior is counter-intuitive: the erosion rate is half the baseline rate ${u_0}/2$ plus the geometric mean of the two speeds $\sqrt{ {\lambda} {\eta_0} {u_0} }$; for very fast weathering, the multiplicative average dominates.

The weathering rate alone never limits the rate of erosion, so the concept of weathering limitation does not apply in the traditional sense.

Code

The code is provided as a Python package and Jupyter notebooks.

References

  1. Inoue, T., Yamaguchi, S., and Nelson, J. M., 2017.. "The effect of wet-dry weathering on the rate of bedrock river channel erosion by saltating gravel", Geomorphology, 285, 152–161.

  2. Li, K., Ma, L., Li, X., and Peng, S., 2016. "Effect of drying-wetting cycles on triaxial compression mechanical properties of sandstone", Journal of Engineering Science and Technology Review, 9, 66–73.

  3. Stark, C.P., and Stark, G.J., 2022. "The direction of landscape erosion", Earth Surface Dynamics, 10: 383-419.

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

wmbe-0.1.25.tar.gz (37.4 kB view details)

Uploaded Source

Built Distribution

If you're not sure about the file name format, learn more about wheel file names.

wmbe-0.1.25-py3-none-any.whl (40.7 kB view details)

Uploaded Python 3

File details

Details for the file wmbe-0.1.25.tar.gz.

File metadata

  • Download URL: wmbe-0.1.25.tar.gz
  • Upload date:
  • Size: 37.4 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/6.1.0 CPython/3.13.12

File hashes

Hashes for wmbe-0.1.25.tar.gz
Algorithm Hash digest
SHA256 1bf4954e1e41022dc7d30d72d406a5fd51b1d0865fc36fbb2863e10bbd26eb15
MD5 4b8f23a5a6aa295452d70ee15efca3ef
BLAKE2b-256 6797bfa3ca8ebf6ebc5240fb307e35147d294f7df04bb110513bf8d8b4628192

See more details on using hashes here.

Provenance

The following attestation bundles were made for wmbe-0.1.25.tar.gz:

Publisher: pypi-publish.yml on cstarkjp/WMBE

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file wmbe-0.1.25-py3-none-any.whl.

File metadata

  • Download URL: wmbe-0.1.25-py3-none-any.whl
  • Upload date:
  • Size: 40.7 kB
  • Tags: Python 3
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/6.1.0 CPython/3.13.12

File hashes

Hashes for wmbe-0.1.25-py3-none-any.whl
Algorithm Hash digest
SHA256 a938b1e644d359d48ca297eaf235b6f54523b862abd9d4133582f320e0bbbacd
MD5 b667838558d9707abe22fd909c9ec0a3
BLAKE2b-256 b698d42685176f4c2369d7691e30d9d7f9baac6e7d85ccb7992e2619044103d4

See more details on using hashes here.

Provenance

The following attestation bundles were made for wmbe-0.1.25-py3-none-any.whl:

Publisher: pypi-publish.yml on cstarkjp/WMBE

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Supported by

AWS Cloud computing and Security Sponsor Datadog Monitoring Depot Continuous Integration Fastly CDN Google Download Analytics Pingdom Monitoring Sentry Error logging StatusPage Status page