Skip to content

Commit a348a8d

Browse files
Refactor method descriptions in model documentation
1 parent 9d0683f commit a348a8d

1 file changed

Lines changed: 21 additions & 16 deletions

File tree

docs/user/model_description.rst

Lines changed: 21 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -985,7 +985,8 @@ The vegetation method is selected using ``method_vegetation``. The model current
985985
Vegetation Metrics
986986
^^^^^^^^^^^^^^^^^^^
987987

988-
(**method** ``duran``) The basal vegetation density :math:`\rho_{\text{veg}}` (``rhoveg``) [:math:`\mathrm{-}`] can vary in space and time. It is determined by the ratio of the actual vegetation height :math:`h_{\text{veg}}` (``hveg``) [:math:`\mathrm{m}`] to the maximum attainable vegetation height :math:`H_{\text{veg}}` (``Hveg``) [:math:`\mathrm{m}`], varying between 0 and 1 :cite:`DuranHerrmann2006`:
988+
**Method** ``duran`
989+
The basal vegetation density :math:`\rho_{\text{veg}}` (``rhoveg``) [:math:`\mathrm{-}`] can vary in space and time. It is determined by the ratio of the actual vegetation height :math:`h_{\text{veg}}` (``hveg``) [:math:`\mathrm{m}`] to the maximum attainable vegetation height :math:`H_{\text{veg}}` (``Hveg``) [:math:`\mathrm{m}`], varying between 0 and 1 :cite:`DuranHerrmann2006`:
989990

990991
.. math::
991992
:label: Vegetation_density_duran
@@ -994,7 +995,9 @@ Vegetation Metrics
994995
995996
This assumption is based on the idea that burying vegetation reduces its height, which indicates a simultaneous decrease in actual cover. The change in vegetation density per grid cell is directly linked to the alteration in vegetation height within that specific cell.
996997

997-
(**method** ``grass``) The new framework decouples plant structure into two independent state variables: tiller density :math:`N_t` (``N_t``) [:math:`\mathrm{tillers/m^2}`] and tiller height :math:`h_{\text{veg}}` (``hveg``) [:math:`\mathrm{m}`]. This separation enables the representation of distinct morphological states, such as sparse/tall canopies or dense/short canopies.
998+
**Method** ``grass``
999+
1000+
The new framework decouples plant structure into two independent state variables: tiller density :math:`N_t` (``N_t``) [:math:`\mathrm{tillers/m^2}`] and tiller height :math:`h_{\text{veg}}` (``hveg``) [:math:`\mathrm{m}`]. This separation enables the representation of distinct morphological states, such as sparse/tall canopies or dense/short canopies.
9981001

9991002
To capture fine-scale spatial dynamics, such as clonal expansion, these vegetation metrics and their subsequent developmental processes are resolved on an automatically generated higher-resolution sub-grid (:math:`\Delta x \leq 1` m). The resolution increase can be set using the ``veg_res_factor``. To prevent excessive computational demand, the timestepping for the vegetation module specifically can be adjusted using ``dt_veg``.
10001003

@@ -1019,7 +1022,7 @@ Here, :math:`r_{\text{stem}}` [:math:`\mathrm{-}`] (``r_stem``) specifies the fr
10191022
Vegetation Development
10201023
^^^^^^^^^^^^^^^^^^^^^^^
10211024

1022-
**Method:** ``duran``
1025+
**Method** ``duran``
10231026

10241027
Vegetation growth and decay follow the model proposed by :cite:`DuranHerrmann2006`, modified to include an optimal burial rate :math:`\Delta z_{\text{b,opt}}` [:math:`\mathrm{m/yr}`] that shifts the peak of optimal growth:
10251028

@@ -1035,28 +1038,30 @@ The optimal burial rate for maximum vegetation growth for marram grass is around
10351038
.. tip::
10361039
Meaning of these variables: An intrinsic vertical growth rate of :math:`V_{\text{ver}} = 4` m/year does not mean the vegetation will be 4 meters high after 1 year, as growth follows a logistic curve that slows as it reaches :math:`H_{\text{veg}}`.
10371040

1038-
**Method:** ``grass``
1041+
**Method** ``grass``
10391042

10401043
Vegetation development is simulated through two completely decoupled processes: vertical tiller growth and horizontal tiller establishment (:ref:`fig-vegetation-development`).
10411044

10421045
.. _fig-vegetation-development:
10431046

1044-
.. figure:: /images/vegetation_growth.mp4
1045-
:width: 900px
1046-
:align: center
1047+
.. video:: /images/vegetation_growth.mp4
1048+
:autoplay:
1049+
:loop:
1050+
:muted:
1051+
:width: 80%
10471052

10481053
Simulated spatial and temporal evolution of tiller density and height demonstrating local growth, clonal expansion, seedling dispersal, and inter-species competition.
10491054

10501055

10511056
**1. Vertical Tiller Growth:**
1052-
Vertical growth utilizes a generalized logistic growth equation, driven by the intrinsic growth rate :math:`G_h` [:math:`\mathrm{m/yr}`] and an exponent :math:`\phi_h` [:math:`\mathrm{-}`] that provides greater control over the growth trajectory:
1057+
Vertical growth utilizes a generalized logistic growth equation, driven by the intrinsic growth rate :math:`G_h` [:math:`\mathrm{m/yr}`] (``G_h``) and an exponent :math:`\phi_h` [:math:`\mathrm{-}`] (``phi_h``) that provides greater control over the growth trajectory:
10531058

10541059
.. math::
10551060
:label: growth_height_grass
10561061
10571062
\frac{\partial h_{\text{veg}}}{\partial t} = G_h \left(1 - \frac{h_{\text{veg}}}{H_{\text{veg}}}\right)^{\phi_h} + B_h
10581063
1059-
The response to sediment burial and erosion :math:`B_h` relies on the sensitivity parameter :math:`\gamma_h` [:math:`\mathrm{-}`] and an optimal burial rate :math:`\Delta z_{\text{opt},h}` [:math:`\mathrm{m/yr}`] (e.g., 0.2–1.0 m/yr for marram grass), producing an asymmetric response to burial versus erosion.
1064+
The response to sediment burial and erosion :math:`B_h` relies on the sensitivity parameter :math:`\gamma_h` [:math:`\mathrm{-}`] (``gamma_h``) and an optimal burial rate :math:`\Delta z_{\text{opt},h}` [:math:`\mathrm{m/yr}`] (e.g., 0.2–1.0 m/yr for marram grass) (``dzb_opt_h``), producing an asymmetric response to burial versus erosion.
10601065

10611066
**2. Horizontal Tiller Establishment (Density):**
10621067
Tiller density evolves through the recruitment of new tillers via seedling germination (:math:`s`) and clonal expansion (:math:`c`). Tiller production occurs in a source cell (:math:`j`) and is distributed to a target cell (:math:`i`) based on dispersal weights :math:`w_{ij}`:
@@ -1066,7 +1071,7 @@ Tiller density evolves through the recruitment of new tillers via seedling germi
10661071
10671072
\frac{\partial N_{t,i}}{\partial t} = \sum_j w^{(s)}_{ij} S_{s,j} \;+\; \sum_j w^{(c)}_{ij} S_{c,j} \left(1 - \sum_n \alpha_{AB} \frac{\bar{N}_{t,i}^{(B)}}{N_{t,\text{max}}^{(B)}}\right)
10681073
1069-
To account for inter-specific competition in multi-species simulations, the logistic saturation term utilizes a Lotka-Volterra approach, where :math:`\alpha_{AB}` [:math:`\mathrm{-}`] defines the competitive effect of species :math:`A` on target species :math:`B`. Production in the source cell is calculated via:
1074+
To account for inter-specific competition in multi-species simulations, the logistic saturation term utilizes a Lotka-Volterra approach, where :math:`\alpha_{AB}` [:math:`\mathrm{-}`] (``alpha_comp``) defines the competitive effect of species :math:`A` on target species :math:`B`. Production in the source cell is calculated via:
10701075

10711076
.. math::
10721077
:label: tiller_production
@@ -1083,7 +1088,7 @@ The spatial dispersal mechanisms differ fundamentally:
10831088
Vegetation-induced Shear Reduction
10841089
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
10851090

1086-
**Method:** ``duran``
1091+
**Method** ``duran``
10871092

10881093
Inspired by the Coastal Dune Model (CDM), AeoLiS incorporates vegetation-wind interaction using the simplified expression:
10891094

@@ -1094,7 +1099,7 @@ Inspired by the Coastal Dune Model (CDM), AeoLiS incorporates vegetation-wind in
10941099
10951100
The ratio of shear velocity in the presence of vegetation (:math:`u_{*,\text{veg}}`) [:math:`\mathrm{m/s}`] to the unobstructed shear velocity (:math:`u_*`) [:math:`\mathrm{m/s}`] is driven by the basal vegetation cover :math:`\rho_{\text{veg}}` and a fixed vegetation-related roughness parameter :math:`\Gamma` (``gamma_vegshear``, default = 16) [:math:`\mathrm{-}`].
10961101

1097-
**Method:** ``grass``
1102+
**Method** ``grass``
10981103

10991104
Rather than relying on the basal cover assumption, the updated framework calculates local shear velocity reduction by explicitly using the frontal area index :math:`\lambda_{\text{veg}}`:
11001105

@@ -1128,11 +1133,11 @@ Here, :math:`c_1` [:math:`\mathrm{-}`] is a dimensionless calibration constant c
11281133
Computing bed-interaction (zeta) over vegetation
11291134
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
11301135

1131-
**Method:** ``duran``
1136+
**Method** ``duran``
11321137

11331138
In the standard advection scheme, the model implicitly assumes that local bed properties dictate the saturation concentration for the entire transport column. Therefore, the bed-interaction factor :math:`\zeta` [:math:`\mathrm{-}`] is essentially assumed to be 1, meaning any reduction in shear stress due to vegetation immediately forces the entire sediment flux to deposit.
11341139

1135-
**Method:** ``grass``
1140+
**Method** ``grass``
11361141

11371142
To capture realistic "skimming" flows over dense grass canopies, the new framework divides the saturation concentration :math:`c_{\text{sat}}` into two distinct modes (:ref:`fig-vegetation-sediment-transport`):
11381143

@@ -1171,11 +1176,11 @@ The final bed-interaction factor accounts for airborne sediment bouncing through
11711176
Vegetation Mortality
11721177
^^^^^^^^^^^^^^^^^^^^^^^^
11731178

1174-
**Method:** ``duran``
1179+
**Method** ``duran``
11751180

11761181
Vegetation is subject to destruction caused by hydrodynamic processes. In the event of cell inundation by high water levels, the vegetation density :math:`\rho_{\text{veg}}` in the affected grid cells is instantaneously or proportionally reduced to mimic storm-induced erosion of the canopy.
11771182

1178-
**Method:** ``grass``
1183+
**Method** ``grass``
11791184

11801185
Because tiller height and tiller density are fundamentally coupled, changes in one necessitate updates in the other. Mortality and structural changes occur through three primary drivers:
11811186

0 commit comments

Comments
 (0)