watem_flanders Tool Library¶
Tool Library
| Name | Watem - specific modules for Flanders |
| Author | Johan Van de Wauw 2016 - 2017 - gebaseerd op originele pascal code van KULeuven.Ontwikkeld in opdracht van Vlaamse overheid, departement Omgeving. |
| ID | watem_flanders |
| File | /__w/saga-watem/saga-watem/build/libs/saga/libwatem_flanders.so |
Description
SAGA implementation of WaTEM model (KULeuven), with modules for processing inputfiles.WaTEM/SEDEM is a spatially distributed soil erosion and sediment delivery model that is developed at the Physicaland Regional Geography Research Group (K.U.Leuven, Belgium) as a user-friendly and optimised version of the WaTEM and SEDEM models, which were also developed at K.U.Leuven. These models were specifically developed to simulate the impact of soil conservation and sediment control measures as well as land use changes in the framework of an integrated catchment management, on the local soil loss and sediment delivery to rivers. This model combines the WaTEM and SEDEM models and aims at providing useful information for land managers to select the most effective catchment management scenario.).
Tools
[1] Prepare parcel Map¶
Tool
| Name | Prepare parcel Map |
| Author | Johan Van de Wauw (2017) |
| Version | 2023.10.23 |
| Library | watem_flanders |
| ID | 1 |
| Specification | grid |
Description
Flanders specific: Creates a parcel grid for creating the erosion map based on parcel map, 'Grootschalig Referentie Bestand' (GRB), the 'Vlaams Hydrologische Atlas' (VHA) and Landcover map. Returns parcels with codes:- infrastructure and roads: -2
- water (open water / river): -1
- parcels: [2,9999]
- forest: 10000
Only the geometry of the input shapes is used for mapping. Note that the input instruction refers to data specific attributes (i.e. GRB, VHA, in dutch). We refer to the GRB and VHA metadata at 'datavindplaats' of www.vlaanderen.be for more information. GRB overwrites parcel, river overwrites GRB.
Parameters
| Name | Type | Identifier | Description | Constraints |
|---|---|---|---|---|
| Input | ||||
| Parcels | Shapes, input | PARCEL_SHAPES | Polygon shape of parcels. | |
| Landcover | Grid, input | LANDCOVER | Landcover with values 10000, -1 and -2. | |
| GRB WTZ (VHA-polygon) | Shapes, input | WTZ | VHA (polygons). | |
| VHA lines | Shapes, input | WLAS | VHA (lines). | |
| GRB Sbn (spoorbaan) | Shapes, input | SBN | GRB Sbn (spoorbaan). | |
| GRB Wbn (wegbaan) | Shapes, input | WBN | GRB Wbn (wegbaan). | |
| GRB Wga (wegaanhorigheid) | Shapes, input | WGA | GRB Wga (wegaanhorigheid). | |
| GRB Gbg (gebouw aan de grond) | Shapes, input | GBG | GRB Gbg (gebouw aan de grond). | |
| GRB Gba (gebouwaanhorigheid) | Shapes, input | GBA | GRB Gba (gebouwaanhorigheid). | |
| (NOT IMPLEMENTED) GRB Trn (terrein) | Shapes, input | TRN | GRB Trn (Terrein) - only certain classes are used | |
| GRB Knw (Kunstwerk) | Shapes, input | KNW | GRB Knw (Kunstwerk) | |
| Output | ||||
| Parcel grid | Grid, output | PRC | Output grid with: - a unique identifier per parcel: [2,9999] - Forest = 10000 - Infrastructure & roads = -2 - Water (rivers and open water) = -1 | |
[2] 3x3 filter within parcel boundaries¶
Tool
| Name | 3x3 filter within parcel boundaries |
| Author | Copyright (c) 2017. Johan Van de Wauw |
| Version | 2023.10.23 |
| Library | watem_flanders |
| ID | 2 |
| Specification | grid |
Description
The tool performs a 3x3-mean filter on a digital elevation model using only cells within a singular parcel.Parameters
| Name | Type | Identifier | Description | Constraints |
|---|---|---|---|---|
| Input | ||||
| Digital elevation model (DEM) | Grid, input | DEM | Digital elevation model (m) | |
| Parcel grid | Grid, input | PRC | Parcel grid with: - a unique identifier per parcel: [2,9999] - Forest = 10000 - Infrastructure & roads = -2 - Water (rivers and open water) = -1 | |
| Output | ||||
| Filtered DEM | Grid, output | DEM_FILTER | DEM filtered with a 3x3-mean filter that is active only within parcel boundaries. | |
[3] C calculation based on parcel grid¶
Tool
| Name | C calculation based on parcel grid |
| Author | Copyright (c) 2017, Johan Van de Wauw |
| Version | 2023.10.23 |
| Library | watem_flanders |
| ID | 3 |
| Specification | grid |
Description
Calculation of the C-factor (crop and management factor) map based on parcel grid. Uses fixed constants:- 0.37 for cropland (code in [2,9999]
- 0 for rivers infrastructure/roads (code = -1 and -2)
- 0.001 for forests (code = 10000)
Parameters
| Name | Type | Identifier | Description | Constraints |
|---|---|---|---|---|
| Input | ||||
| Parcel grid | Grid, input | PRC | Parcel grid with: - a unique identifier per parcel: [2,9999] - Forest = 10000 - Infrastructure & roads = -2 - Water (rivers and open water) = -1 | |
| Output | ||||
| C Grid | Grid, output | C | C-factor Grid | |
[4] C calculation shape attribute¶
Tool
| Name | C calculation shape attribute |
| Author | Copyright (c) 2022, Johan Van de Wauw |
| Version | 2023.10.23 |
| Library | watem_flanders |
| ID | 4 |
| Specification | grid |
Description
Calculation of the C (crop and management factor) map based on landcover raster. Optionally GRB and VHA can be added, geometries of this shapes are mapped to a C-factor value of 0. The C-factor for parcels are set to 0.37. The C-factor for Landuse forest is converted 0.01. Only the geometry of the input shapes is used for mapping. Note that the input instruction refers to data specific attributes (i.e. GRB, VHA, in dutch). We refer to the GRB and VHA metadata at 'datavindplaats' of www.vlaanderen.be for more information. For a mapping table, we refer to 'Prepare parcel Map' and 'C calculation based on parcel grid'. GRB overwrites landuse.Parameters
| Name | Type | Identifier | Description | Constraints |
|---|---|---|---|---|
| Input | ||||
| Parcels | Shapes, input | PARCEL_SHAPES | Polygon shape of parcels. Should contain 'C Field'. | |
| landcover grid | Grid, input | LANDCOVER | landcover grid with - Forest = 10000 - Infrastructure & roads = -2 - Water = -1 | |
| GRB WTZ (VHA-polygon) | Shapes, input, optional | WTZ | VHA (polygons). | |
| VHA lines | Shapes, input, optional | WLAS | VHA (lines). | |
| GRB Sbn (spoorbaan) | Shapes, input, optional | SBN | GRB Sbn (spoorbaan) | |
| GRB Wbn (wegbaan) | Shapes, input, optional | WBN | GRB Wbn (wegbaan) | |
| GRB Wga (wegaanhorigheid) | Shapes, input, optional | WGA | GRB Wga (wegaanhorigheid) | |
| GRB Gbg (gebouw aan de grond) | Shapes, input, optional | GBG | GRB Gbg (gebouw aan de grond) | |
| GRB Gba (gebouwaanhorigheid) | Shapes, input, optional | GBA | GRB Gba (gebouwaanhorigheid) | |
| (NOT IMPLEMENTED) GRB Trn (terrein) | Shapes, input, optional | TRN | GRB Trn (Terrein) - only certain classes are used | |
| GRB Knw (Kunstwerk) | Shapes, input, optional | KNW | GRB Knw (Kunstwerk) | |
| Output | ||||
| C Grid | Grid, output | C | C-factor Grid | |
| Options | ||||
| C Field | Table field | PARCEL_SHAPE_C_FIELD | Field name containing C-factor value | |
| Use GRB and VHA as extra landuse (True/False) | Boolean | GRB_VHA | Default: 0 | |
[5] Complete Calculation Erosion map (combines all steps). See submodules for more information.¶
Tool
| Name | Complete Calculation Erosion map (combines all steps). See submodules for more information. |
| Author | Based on Watem (KULeuven). Converted to SAGA by Johan Van de Wauw (2016-2017) |
| Version | 2023.10.23 |
| Library | watem_flanders |
| ID | 5 |
| Specification | grid |
Description
Complete computation erosion raster in one step. This model executes following steps:- Calculate upslope area (watem-1)
- LS calculation (watem-2)
- C calculation based on parcel grid (watem-flanders-3)
- Watererosion based on LS (RUSLE) (optional tillage erosion) (watem-3 and watem-4).
A NULL value in K, C or LS return a NULL value.
Parameters
| Name | Type | Identifier | Description | Constraints |
|---|---|---|---|---|
| Input | ||||
| DEM | Grid, input | DEM | Digital elevation model. | |
| Parcel grid | Grid, input | PRC | Parcel grid with: - a unique identifier per parcel: [2,9999] - Forest = 10000 - Infrastructure & roads = -2 - Water (rivers and open water) = -1 | |
| K-factor grid | Grid, input | K | soil erodibility factor (K-factor, kg ha MJ-1 mm-1) | |
| Output | ||||
| Pit | Grid, output | PIT | Pit id. These id's are linked to the id's in pit data (see watem-1 Calculate uparea) | |
| Upslope area | Grid, output | UPSLOPE_AREA | Upslope Area: area that flow to a certain pixel (see watem-1 Calculate uparea) | |
| LS | Grid, output | LS | LS as defined by return tool (see watem-2, LS calculation) | |
| Tillage Erosion | Grid, output, optional | TILL | Average soil loss due to tillage erosion (kg ha-1 year-1) | |
| Water erosion | Grid, output | WATER_EROSION | Average soil loss due to rill and interrill erosion (kg ha-1 jaar-1) | |
| Options | ||||
| R-factor value | Floating point | R | rainfall erosivity factor (MJ mm ha-1 year-1) | Minimum: 0.000000 Default: 880.000000 |
| P-factor value | Floating point | P | erosion control factor (-) | Minimum: 0.000000 Default: 1.000000 |
| Resolution correction factor | Floating point | CORR | Correction factor for resolution as RUSLE was determined on resolution of 22.1 meter. This value is set to 1.4 for grids of 5x5 (see Notebaert et al. 2006) | Minimum: 0.000000 Default: 1.400000 |
| Parcel Connectivity to cropland (%) | Floating point | PCTOCROP | Percentage of water that will be reduced to go from a cropland to another cropland. | Minimum: 0.000000 Default: 70.000000 |
| Parcel Connectivity to forest (%) | Floating point | PCTOFOREST | Percentage of water that will be reduced to go from a cropland to forest. | Minimum: 0.000000 Default: 100.000000 |
| Save memory | Boolean | SAVE_MEMORY | Option to reduce memory for computation. Warning: can increase computationt time. | Default: 0 |
| Flow from pits into closeby cells (within radius) (True/False) | Boolean | PIT_FLOW | Default: 1 | |
| Search radius from pit. | Integer | PIT_RADIUS | Maximum radius from a pit to which upstream water can flow | Default: 4 |
| Use parcel boundary for computations | Boolean | LS_USE_PRC | Compute slope/LS within boundaries of parcels. | Default: 1 |
| Method to compute LS | Choice | METHOD | Available Choices: [0] Moore & Nieber 1989 [1] Desmet & Govers 1996 (standard WaTEM) [2] Wischmeier & Smith 1978 [3] Van Oost, 2003 Default: 1 | |
| Flag maximum gross erosion | Boolean | EROSION_CROP_MAX | Use maximum allowed erosion per pixel (True/false) | Default: 1 |
| Maximum allower gross erosion. | Floating point | EROSION_MAX | Maximum allowed erosion per pixel, higher values are set to this value. | Minimum: 0.000000 Default: 150.000000 |