Class StraMesh

class sed.stratplex.STRAMesh

This class encapsulates all the functions related to underlying stratigraphic information. Sediment compaction in stratigraphic layers geometry and properties change are also considered.

Methods

deposeStrat()	Add deposition on top of an existing stratigraphic layer.
elevStrat()	This function updates the current stratigraphic layer elevation.
erodeStrat()	This function removes eroded sediment thicknesses from the stratigraphic pile.
getCompaction()	This function computes the changes in sedimentary layers porosity and thicknesses due to compaction.
readStratLayers()	When stratigraphic layers are turned on, this function reads any initial stratigraphic layers provided by within the YAML input file (key: npstrata).
stratalRecord(indices, weights, onIDs)	Once the interpolation has been performed, the following function updates the stratigraphic records based on the advected mesh.

Initialise

__init__()

The initialisation of STRAMesh class related to stratigraphic informations.

Public Methods

deposeStrat()	Add deposition on top of an existing stratigraphic layer.
erodeStrat()	This function removes eroded sediment thicknesses from the stratigraphic pile.
elevStrat()	This function updates the current stratigraphic layer elevation.
getCompaction()	This function computes the changes in sedimentary layers porosity and thicknesses due to compaction.
readStratLayers()	When stratigraphic layers are turned on, this function reads any initial stratigraphic layers provided by within the YAML input file (key: npstrata).
stratalRecord(indices, weights, onIDs)	Once the interpolation has been performed, the following function updates the stratigraphic records based on the advected mesh.

Private Methods

_depthPorosity(depth)

This function uses the depth-porosity relationships to compute the porosities for each lithology and then the solid phase to get each layer thickness changes due to compaction.

Public functions

STRAMesh.deposeStrat()

Add deposition on top of an existing stratigraphic layer. The following variables will be recorded:

• thickness of each stratigrapic layer stratH accounting for both erosion & deposition events.

• porosity of sediment phiS in each stratigraphic layer computed at center of each layer.

STRAMesh.erodeStrat()

This function removes eroded sediment thicknesses from the stratigraphic pile. The function takes into account the porosity values of considered lithologies in each eroded stratigraphic layers.

It follows the following assumptions:

• Eroded thicknesses from stream power law and hillslope diffusion are considered to encompass both the solid and void phase.

• Only the solid phase will be moved dowstream by surface processes.

• The corresponding deposit thicknesses for those freshly eroded sediments correspond to uncompacted thicknesses based on the porosity at surface given from the input file.

STRAMesh.elevStrat()

This function updates the current stratigraphic layer elevation.

STRAMesh.getCompaction()

This function computes the changes in sedimentary layers porosity and thicknesses due to compaction.

Note

We assume simple depth-porosiy relationships for each sediment type available in each layers.

STRAMesh.readStratLayers()

When stratigraphic layers are turned on, this function reads any initial stratigraphic layers provided by within the YAML input file (key: npstrata).

The following variables will be read from the file:

• thickness of each stratigrapic layer strataH accounting for both erosion & deposition events.

• elevation at time of deposition, considered to be to the current elevation for the top stratigraphic layer strataZ.

• porosity of coarse sediment phiS in each stratigraphic layer computed at center of each layer.

STRAMesh.stratalRecord(indices, weights, onIDs)

Once the interpolation has been performed, the following function updates the stratigraphic records based on the advected mesh.

The function relies on fortran subroutines strataonesed.

Parameters:

• indices – indices of the closest nodes used for interpolation

• weights – weights based on the distances to closest nodes

• onIDs – index of nodes remaining at the same position.

Private functions

STRAMesh._depthPorosity(depth)

This function uses the depth-porosity relationships to compute the porosities for each lithology and then the solid phase to get each layer thickness changes due to compaction.

Note

We assume that porosity cannot increase after unloading.

Parameters:

depth – depth below basement for each sedimentary layer

Returns:

newH updated sedimentary layer thicknesses after compaction