Subsidence Overlay: Difference between revisions

Latest revision as of 14:19, 28 February 2024

The subsidence overlay

The ground water overlay

The Subsidence Overlay is an overlay that shows which places in the project area are subject to subsidence due to oxidation and/or compaction of peat. The calculation results can provide insight into the subsidence taking place, and the effects it has on groundwater levels.

The Subsidence Overlay can be used to calculate the amount of subsidence which takes place on peat soil, specifically due to peat oxidation and compaction. The calculations are specific for peat soil. Separate formulas for other soil types have not yet been implemented. Although it's possible to use the overlay to give an impression of subsidence resulting from other factors, the results will be less accurate. This means that results have a greater margin of error for different use-cases.

It is possible to add multiple subsidence overlays to a project. By varying their configuration slightly, it is possible to calculate multiple scenario's or time-frames simultaneously.

A project can be enriched with other overlays that are interesting in combination with the Subsidence Overlay. Examples are:

The initial Groundwater level calculated by the Groundwater Overlay
The Waterwijzer Overlay which calculates the yield loss of crops based on several parameters such as Subsidence

How-to's

Module

A Subsidence Overlay can be configured by opening the Subsidence Overlay Wizard. More in-depth information can be found under each of the categories below.

Group: Model
Model

Overview • Calculation • Theory
Formulas

Parameter a recalculation • Ground water depth • Oxidation • Compaction • Subsidence • Indexation
Related

Features • Model attributes • Rasters • Result type

Categorization

Grid • Parent • Result Child • Result Parent • Result type
Default

City
Administrative

Ownership • Ownership Grid • Zipcodes • Zoning • Neighborhoods • Municipalities • Vacancy
Environmental

Heat Stress • Traffic Density • Traffic Noise • Traffic NO2 • Livability
Water

Rainfall • Flooding • Groundwater • Subsidence • Watershed
Grid Calculation

Average • Combo • Distance • Sight Distance • Travel Distance • Inference • Iteration

Geo Data

GeoTIFF • WCS • WMS • Image • Area • Attribute • Function
Topography

Satellite • Digital Surface Model • Digital Terrain Model • Underground • Source
Network

Network Distance • Network Overview • Network Ownership

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-{{stub}}
+[[File:Subsidence-Overlay.jpg|thumb|200px|right|The subsidence overlay]]
+[[File:Groundwater-Overlay.jpg|thumb|200px|right|The ground water overlay]]
+The Subsidence Overlay is an [[Grid overlay|overlay]] that shows which places in the [[project area]] are subject to subsidence due to oxidation and/or compaction of peat. The [[subsidence calculation|calculation]] results can provide insight into the subsidence taking place, and the effects it has on groundwater levels.
-{{learned|what the Subsidence overlay is|what information is displayed by the subsidence overlay|how to configure the subsidence overlay}}
+The Subsidence Overlay can be used to calculate the amount of subsidence which takes place on peat soil, specifically due to peat oxidation and compaction. The calculations are specific for peat soil. Separate formulas for other soil types have not yet been implemented. Although it's possible to use the overlay to give an impression of subsidence resulting from other factors, the results will be less accurate. This means that results have a greater margin of error for different use-cases.
-==What is the subsidence overlay==
+It is possible to add multiple subsidence overlays to a project. By varying their configuration slightly, it is possible to calculate multiple scenario's or time-frames simultaneously.
-The subsidence overlay is a [[grid overlay]], and part of the [[subsidence calculation|subsidence collection]] of overlays. It shows which places in the [[3D world]] are subject to subsidence due to oxidation and/or compaction of peat.
-==How the subsidence overlay calculates==
+A project can be enriched with other overlays that are interesting in combination with the Subsidence Overlay. Examples are:
-Subsidence is currently composed of 2 forms of reduction of peat: oxidation and compaction. These forms of subsidence are both relevant for the complete picture of subsidence, but are, in principle, calculated via separate formulas. The results of these formulas are added together to get the total amount of subsidence.
-===Oxidation===
+* The initial [[Ground_watertable_result_type_(Water_Overlay)|Groundwater level]] calculated by the [[Groundwater Overlay]]
-Peat, when exposed to oxygen, can oxidize. In this process the peat combines with the air to form CO2, reducing the total mass and volume of the peat. The amount of oxidation depends on the clay thickness, because clay may insulate the peat, preventing it from oxidizing. It also depends on the (lowest) ground water level in relation to the surface of the land.
+* The [[Waterwijzer_Overlay|Waterwijzer Overlay]] which calculates the yield loss of crops based on [[Waterwijzer_Overlay#Considerations|several parameters such as Subsidence]]
-For information on the exact calculation of subsidence due to oxidation, see the article on [[Subsidence calculation#Oxidation Calculation|Subsidence calculation]].
+{{article end
-===Compaction===
+|howtos=
-Peat is a porous and relatively soft terrain type, meaning it can be compressed. Based on the amount of peat in the ground, the density of the top layer, and the net height increase.
+* [[How to add and remove an Overlay]]
+* [[How to edit an overlay legend|Edit an overlay legend]]
+}}
-For information on the exact calculation of subsidence due to compaction, see the article on [[Subsidence calculation#Compaction calculation|Subsidence calculation]].
+==Module==
-===Multi-year calculations===
+A Subsidence Overlay can be configured by opening the Subsidence Overlay Wizard. More in-depth information can be found under each of the categories below.
+{{SubsidenceOverlay_nav}}
-Subsidence is calculated in 1-year steps. For each year, the amount of subsidence is calculated. That amount is then used to recalculate the input parameters for the overlay. The next 1-year step is then calculated.
+[[Category:Overlays with result types]]
+{{Overlay nav}}
-For more information on the way the multi-year calculation is performed, see [[Subsidence calculation]].
-==How to configure the subsidence overlay==
-When the subsidence overlay is added to a project, there is some minimum information required for a calculation. The compaction calculation already functions based on data present in the engine, but requires a running session and specific actions to be taken. The oxidation calculation can show results without taking actions, provided that the required data is loaded in.
-===Oxidation===
-The following data must be added to a project for the oxidation calculation:
-{| class="wikitable"
-! Attribute
-! Description
-! Name to import as
-|-
-| Water level
-| The areas with the relevant data must have a water level attribute to mark them as water level areas.
-| WATER_LEVEL
-|-
-| Ground water level
-| A ground water level, in meters from the surface of the land. The larger the value, the dryer the soil is. Should be greater than 0. (Can also be 0, but there will be no subsidence then.)
-| GLG
-|-
-| Clay thickness
-| The thickness of the layer of clay on the top of the soil, in meters. The thicker the layer, the less subsidence occurs. Should be 0, or greater than 0.
-| CLAY_THICKNESS
-|}
-There are 2 ways of getting this data into your project: by importing it (i.e. your own data) into the [[project]] as [[area]]s with [[attribute]]s, or by manually drawing the appropriate [[area]]s and adding [[attribute]]s to those.
-It is possible to load in your own [[GeoJSON]] file with information which is relevant to the oxidation calculations. When this data is loaded in, results of the calculations will become visible in the 3D world when the overlay is selected.
-To import you own file, you must prepare a [[GeoJSON]] file with the specified data in the [[GeoJSON#How to prepare a GIS file|correct format]]. The file should contain the data listed above. When the file is prepared, it can be [[GeoJSON#How to load a GeoJSON file into the engine|imported]] via the option in the ribbon, or by dragging the file into the Engine. The file must be imported as [[area]]s. When importing, the attributes must be renamed to the attribute names listed above.
-{{Editor steps|title=configure oxidation subsidence by importing data|Drag your GeoJSON file into the editor|Select "Import as [[area]]s|Rename the ground water level attribute to "GLG"|Rename the clay thickness attribute to "CLAY_THICKNESS"|Rename the water level attribute to "WATER_LEVEL"|Select "Send"|Select the subsidence overlay|Select "refresh grid"}}
-When creating the data manually in the [[editor]], you must add at least one area to the [[project]], and to the [[3D World]]. The appropriate attributes (listed above) must be added to the area.
-{{Editor steps|title=configure oxidation subsidence by drawing areas|[[area#Adding and removing areas|Add a new area]] to the project|[[area#Adjust Area|Draw the area]] into the [[3D World]]|[[attribute#How to add and remove attributes|Add the attribute]] "WATER_LEVEL" to the area, with value "-10"|Add the attribute "GLG" to the area, with value "-0,9"|Add the attribute "CLAY_THICKNESS" to the area, with value "0,1"|Select the subsidence overlay|Select "refresh grid"}}

Subsidence Overlay: Difference between revisions

Latest revision as of 14:19, 28 February 2024

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