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| {{learned|what the Water Overlays are|how to configure the Water Overlays}} | | A Water Overlay is a [[Grid Overlay|grid overlay]] for which results are calculated by the [[Water Module]]. The [[Water_Module_Basics|Basic theory of the Water Module]] in the {{software}} is an implementation of a 2D grid based shallow water model based on the 2D Saint Venant equations. The module is further enhanced with infiltration, evaporation, groundwater flow and hydraulic structures. Depending on the use case, the simulated period can be set to few seconds and up to a few months. The [[Water_Module_Theory|theory]] section describes in detail how calculations are performed. |
| | __NOTOC__ |
| | To perform the calculations, the project area is divided into a [[Grid overlay|grid of cells]]. Each cell has a specific quantity of water and specific hydrological parameters based on the data in the project. The total time which should be simulated is divided into discrete [[Timestep formula (Water Overlay)|timesteps]]. Per timestep, each cell communicates with its adjacent cells to exchange water, based on its water level, surface height, current flow direction and other factors. Accuracy and reliability is obtained by dividing the project area and simulation time into sufficiently small cells and steps, at the cost of more computation time. |
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| ==What are the Water Overlays==
| | The final results of the calculation can be inspected, as well as intermediate snapshots of the hydrological situation during the simulation, known as [[Timeframes (Water Overlay)|timeframes]]. |
| With the Water Overlays the following overlays are meant:
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| * [[Rainfall_(Overlay)|Rainfall Overlay]]
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| * [[Flooding_(Overlay)|Flooding Overlay]]
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| * [[Groundwater_(Overlay)|Groundwater Overlay]]
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| Each of these overlays have some common configuration steps which will be described on this page.
| | ==Variants== |
| | | A Water Module will be initialized by adding one of the following Overlays to a project. Each variant has a number of parameters tuned to best fit specific use-cases. This means that each of these overlays is based on the same theory and calculation method, however they are customized to conveniently provide insight in different aspects of the Water Module. |
| ==Tips on creating a new project when working with the Water Overlays== | |
| When creating a new project in the [[Wizard|new project wizard]], take into account the [[Terrain_height#Terrain_height_in_the_Tygron_Platform|Advanced options]]. In this menu for example the [[GEO_Data|AHN3]] dataset can be selected, which, if available for your project area, provides the most recent heightdata available as Open Data. Also, the [[GEO_Data|IMWA]] dataset is already checked, this means that if available in your project area, Water Level areas and/or Culverts are already imported.
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| ==Configuration Wizard==
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| Each of the Water Overlays has a configuration wizard which helps the user with configuring the overlay.
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| The Configuration Wizard can be found in the General tab of the overlay. <br> <br>
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| [[File:Config_wizard.JPG|900px]] <br><br>
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| For the [[Flooding_(Overlay)|Flooding Overlay]] the wizard has an extra step, the [[Rainfall_(Overlay)|Rainfall]] and [[Groundwater_(Overlay)|Groundwater Overlay]] wizard are basically the same.
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| The settings in the wizard can always be changed after finishing the wizard by opening the wizard again and changing a value and recalculating the overlay.
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| <br>'''Step 1'''
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| In the first step the simulation time is set, based on either a rainfall or without a rainfall. Also the evaporation reference factor (over time) can be set.
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| <br>'''Step 2'''
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| In the second step the elements of the water system can be imported. In some sub-steps the there are four options: to do nothing and proceed, to import the data with the [[Geo_Data_Wizard|Geo data wizard]], or when you already have the data imported to select it based on an attribute of the data or to let the {{software}} automatically generate some data.
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| The following elements can be imported:
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| * the breach areas (only for the [[Flooding_(Overlay)|Flooding overlay]])
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| * water level areas; when automatically generating data one water level area covering the whole project area is created. The water level can be adjusted afterwards.
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| * ground water data
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| * sewer areas; can also be automatically generated based on the urbanization of the project area
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| * inundated areas; these are areas that are already inundated at the start of the flooding
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| * constructions; for the constructions keep in mind that when the data is point data, it has to overlap two water level areas. Therefore make sure the point data is on the border of two water level areas
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| ** Weirs
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| ** Culverts
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| ** Pumps
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| ** Sewer overflows; if chosen to automatically generate the sewer areas, the sewer overflows can also be automatically generated
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| <br>'''Step 3'''
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| Adjust, if needed, the hydrological coefficents used for the calculations for the [[Terrain#Surface|surface terrain]], the [[Terrain#Underground|underground terrain]] and the [[Functions#Function_values|function values]] (for example the amount of water storage for a certain type of building).
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| <br>'''Step 4'''
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| The water system can be made visable with panels and a network visualization.
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| <br>'''Step 5'''
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| In step 5 you have to choose the result types (the different results which can be exported) you want to see after the calculation is done. Some overlays require a threshold value. Read below for the different result types to choose from and the threshold values. One of the overlays can be selected as the first overlay, which then will be visible as the parent Overlay. You can always adjust the result types you want to see later and calculate the Overlay again.
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| Also you can set the number of timeframes in the slider. The timeframes are the intermediate results of the calculation and are not the same as the timesteps. Each timeframe contains numerous timesteps, based on the grid cell size and the speed of the flooding (see for more information the [[Flooding_(Overlay)#Flooding_Model|Courant number]]). The more timeframes you choose, the more insight you will get into the calculation. Each of the timeframe results can be exported.
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| <br>'''Step 6'''
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| In the last step, some additional result types can be chosen to be visualized. Thes overlays contain input data that is used for the calculation, for example the manning value.
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| ==Hydrological features==
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| The water system can be enhanced with a number of hydrological features, which can be loaded in as [[area]]s. These hydrological features form special properties or modifications on the hydrological system.
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| | |
| ===Water level area===
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| A water level area represents real-world water level areas. Within a water level area, the heights of all water [[terrain]]s are set to a specified level.
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| {| class="wikitable"
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| ! Attribute
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| ! Unit
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| ! Description
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| ! Default (when attribute is not present)
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| |-
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| |WATER_LEVEL
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| |mNAP
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| |The water level for all water terrains in this water level area
| |
| |n/a
| |
| |}
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| If no water level area is present in the project, the water level on water terrains is assumed to be extremely low. This allows water to flow into the open water areas at all times.
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| | |
| ===Sewer area===
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| A sewer area is part of the definition of a system of sewers in the specified area. Sewer storage is present in the hydrological model wherever the sewer area intersects with a {{inlink|Sewered constructions|sewered construction}}.
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| {| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Description
| |
| ! Default (when attribute is not present)
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| |-
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| |SEWER_STORAGE
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| |m
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| |The maximum height the water can reach in this sewer. This value, multiplied by the surface area of the sewered constructions the sewer area intersects with, forms the total amount of water this sewer can store.
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| |n/a
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| |-
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| |SEWER_PUMP_SPEED
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| |m3/s
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| |The amount of water removed from the sewer by removing it from the hydrological model entirely.
| |
| |0
| |
| |}
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| Sewers don't have default storage amount, but when generating them automatically in the {{inlink|configuration wizard}}, suggested values are 0,007m for older sewers and 0,04 for newer sewers.
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| | |
| ===Breach===
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| A breach is a modification to the [[terrain height]], with an optional in- or outflow of water for the hydrological model. This can be used to represent calamitous situations, such as a breach in a levee. Breaches can also be used to easily simulate a terrain height increase, effectively creating a levee.
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| | |
| A breach can either be defined solely as a terrain height modification using its {{inlink|SURFACE_OVERRIDE}} attribute, or as an in- or outlet by adding an {{inlink|INLET_Q}} attribute as well. If the breach is only defined as a terrain height change, only water that is already created or defined in some other way in the hydrological model can flow through and from it. If the breach is also given an inlet speed, water will automatically be created or removed uniformly on the breach.
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| {| class="wikitable"
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| ! Attribute
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| ! Unit
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| ! Description
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| ! Default (when attribute is not present)
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| |-
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| |SURFACE_OVERRIDE
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| |mNAP
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| |The new [[terrain height]] at the location of the breach.
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| |n/a
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| |-
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| |INLET_Q
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| |m3/sec
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| |The maximum amount of water flowing into the model through this breach. A negative value means the breach functions as an outlet, and water is removed from the hydrological model.
| |
| |0
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| |-
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| |INLET_CAPACITY
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| |m3
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| |The maximum amount of water which can flow in or out through this breach. Water flowing back in the other direction replenishes the capacity.
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| |Infinite
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| |-
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| |LOWER_THRESHOLD
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| |mNAP
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| |If a lower threshold is set, water will only flow into the model through this breach until the average water level on this breach is equal to or greater than the threshold. If the threshold is not set, the amount of water flowing in is not limited in this fashion.
| |
| |None
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| |-
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| |UPPER_THRESHOLD
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| |mNAP
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| |If an upper threshold is set, water will only flow out the model through this breach until the average water level at the point of this breach is equal to or lower than the threshold. If the threshold is not set, the amount of water flowing out is not limited in this fashion.
| |
| |None
| |
| |}
| |
| Note that a breach shares attribute names with the {{inlink|inlet}}s, and that changing the attribute keys for breaches also affects the keys for inlets.
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| | |
| ===Inundation===
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| An inundation is an initial placement of a quantity of water. This differs from the {{inlink|water level area}}s in that an inundation level allows you to place water anywhere on the surface.
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| {| class="wikitable"
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| ! Attribute
| |
| ! Unit
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| ! Description
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| ! Default (when attribute is not present)
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| |-
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| |INUNDATION_LEVEL
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| |mNAP
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| |The height of the water.
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| |n/a
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| |}
| |
| | |
| ==Hydrological constructions==
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| The water system can be enhanced with a number of hydrological [[construction]]s. These are constructions which effect water flow in specific cells, according to the parameters and rules of the constructions used. The effects of these constructions can be adjusted by setting the appropriate attributes.
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| | |
| Hydrological constructions can be either line-based or point-based:
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| * {{Anchor|Line-based constructions}}'''Line-based constructions'''<br>Line-based constructions form a direct connection between two exact cells, allowing water to flow from one point to another. The flow is dictated by the construction's formula. The endpoints of a line-based construction, the exact cells which are connected by the construction, are computed based on the orientation and size of their polygon. Essentially, the furthest ends of the polygon are used as end-points. Because the cells are considered adjacent, any calculated flow through line-based hydrological constructions is instantaneous.
| |
| * {{Anchor|Point-based constructions}}'''Point-based constructions'''<br>Point-based constructions add or remove water in one or more computational layers, based on their formula's. The centerpoint of a point-based construction, the exact cell where the effect takes place, is is the geometric center of the construction's polygon.
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| | |
| When the calculation of the water overlay completes, the total amount of water which has flowed through a specific construction is stored in an attribute in that construction. By default, this attribute is OBJECT_OUTPUT_FLOW, and the flow is expressed in m3. If multiple water overlays exist in the project simultaneously, the attribute name is appended with a number so that each overlay (as they are added to the project) has a unique attribute it writes its results to.
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| | |
| Hydrological constructions can only function as a single hydrological construction. If a single construction has attributes related to multiple hydrological constructions, the resulting behavior is undefined.
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| | |
| ===Culvert===
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| Culverts are effectively tunnels or pipes directly connecting two bodies of water, and allow water to flow in either direction. Culverts can also be used to model tunnels on land, creating a hole which water can flow through when it is flowing over land. The throughput of a culvert is limited by its dimensions.
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| | |
| A culvert is a {{inlink|Line-based constructions|line-based construction}}.
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| {| class="wikitable"
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| ! Attribute
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| ! Unit
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| ! Description
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| ! Default
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| |-
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| |CULVERT_WIDTH
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| |m
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| |The diameter of the culvert. For throughput calculations, the culvert is assumed to have a spherical cross-section.
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| |1
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| |-
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| |CULVERT_HEIGHT
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| |mNAP
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| |The height of the culvert. (When set to a level lower than the terrain for either endpoint of it, the culvert's height is equal to the height of the (highest) terrain under either endpoint.)
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| |0
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| |-
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| |CULVERT_N
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| |manning value
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| |The manning value of the culvert's material, which influences the flow speed.
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| |0,014
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| |}
| |
| | |
| ===Weir===
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| Weirs are effectively small dams in the water, and allow water to flow from a water body with a higher water level to a lower water level. Any water exceeding the height of the weir can flow over it, increasing the throughput as the water level increases. Strictly, water can flow over the weir in either direction.
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| | |
| A weir is a {{inlink|Line-based constructions|line-based construction}}.
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| {| class="wikitable"
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| ! Attribute
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| ! Unit
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| ! Description
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| ! Default
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| |-
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| |WEIR_HEIGHT
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| |mNAP
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| |The height of the weir.
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| |n/a
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| |-
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| |WEIR_WIDTH
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| |m
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| |The width of the weir.
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| |5
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| |-
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| |WEIR_COEFFICIENT
| |
| |coefficient
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| |The flow coefficient related to the shape of the weir
| |
| |1,1
| |
| |}
| |
| | |
| ===Pump===
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| Pumps are constructions which can move water against its natural flow. Specifically, it moves water from the lower end of the pump to the higher end of the pump. The terrain height is used to determine the low end and the high end of the pump.
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| | |
| A pump is a {{inlink|Line-based constructions|line-based construction}}.
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| {| class="wikitable"
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| ! Attribute
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| ! Unit
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| ! Description
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| ! Default
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| |-
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| |PUMP_SPEED
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| |m3/s
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| |The speed at which water is pumped from the lower water level to the higher water level.
| |
| |n/a
| |
| |}
| |
| If a pump is placed such that both end-points are at locations with equal terrain height, the pump will be inactive and no water will flow through it.
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| | |
| ===Sewer overflow===
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| Sewer overflows are points where water is moved from the sewer area to the above-ground water system. A sewer overflow will allow water to flow through if the water in the sewer exceeds the {{inlink|SEWER_OVERFLOW_THRESHOLD}}, and the water in the connected sewer exceeds the height of the terrain at the location of the sewer overflow.
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| | |
| A sewer overflow is a {{inlink|Point-based constructions|point-based construction}}, and must intersect with a {{inlink|Sewer area|sewer area}}.
| |
| {| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Description
| |
| ! Default
| |
| |-
| |
| |SEWER_OVERFLOW
| |
| |mNAP
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| |The height of the bottom of the sewer, relative to the average terrain height of the connected sewer. Starting from this height, the water level in the sewer must exceed the height of the terrain at the location of the overflow in order for water to flow out.
| |
| |n/a
| |
| |-
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| |SEWER_OVERFLOW_SPEED
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| |m3/s
| |
| |The maximum speed at which water can flow out from the sewer through this overflow.
| |
| |10
| |
| |}
| |
| | |
| ===Inlet===
| |
| Inlets are points where water is either added to or removed from the hydrological model. It will add or remove water at a defined maximum rate, with optional thresholds for the amount of water to add or remove.
| |
| | |
| An inlet is a {{inlink|Point-based constructions|point-based construction}}.
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| {| class="wikitable" | | {| class="wikitable" |
| ! Attribute
| | |[[File:Overlay_rainfall.png]] |
| ! Unit
| | |[[Rainfall_(Overlay)|Rainfall Overlay]] |
| ! Description
| | |provides insight into the water stress and impact caused by (excessive) rainfall |
| ! Default
| |
| |- | |
| |INLET_Q | |
| |m3/sec | |
| |The maximum amount of water flowing into the model through this inlet. A negative value means the construction functions as an outlet, and water is removed from the hydrological model. | |
| |n/a
| |
| |-
| |
| |INLET_CAPACITY
| |
| |m3
| |
| |The maximum amount of water which can flow in or out through this construction. Water flowing back in the other direction replenishes the capacity.
| |
| |Infinite
| |
| |- | | |- |
| |LOWER_THRESHOLD | | |[[File:Overlay_flooding.png]] |
| |mNAP
| | |[[Flooding_(Overlay)|Flooding Overlay]] |
| |If a lower threshold is set, water will only flow into the model through this inlet until the water level at the point of this inlet is equal to or greater than the threshold. If the threshold is not set, the amount of water flowing in is not limited in this fashion.
| | |provides insight into water stress and impact caused by breaches in levees or other sources causing excessive water inflow |
| |None | |
| |- | |
| |UPPER_THRESHOLD | |
| |mNAP
| |
| |If an upper threshold is set, water will only flow out the model through this outlet until the water level at the point of this inlet is equal to or lower than the threshold. If the threshold is not set, the amount of water flowing out is not limited in this fashion.
| |
| |None
| |
| |}
| |
| Note that an inlet shares attribute names with the {{inlink|Breach|breach}}es, and that changing the attribute keys for inlets also affects the keys for breaches.
| |
| | |
| ==Miscellaneous constructions==
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| Besides the constructions which directly influence the main water flow in the hydrological model, there are some constructions which interact with the model in other ways.
| |
| | |
| The effects of these constructions can be adjusted by setting the appropriate attributes. In some cases, these are attributes which relate to [[function value]]s. For these attributes, either can be adjusted to the same effect.
| |
| | |
| In contrast with {{inlink|Hydrological constructions|hydrological constructions}} and their properties, all constructions can have any or all of the following miscellaneous effects.
| |
| | |
| ===Sewered constructions===
| |
| Sewered constructions are constructions under which a sewer exists, and through which water can flow into the sewer. When a sewered connection overlaps with a {{inlink|sewer area}}, that overlap forms an actual sewer, with the storage capacity of the {{inlink|SEWER_STORAGE}} attribute of the sewer area. Any surface water entering the cell of a sewered construction is directly moved to the sewer (unless the sewer is filled to capacity).
| |
| {| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Function value
| |
| ! Description
| |
| |- | | |- |
| |SEWERED | | ||[[File:Overlay_groundwater.png]] |
| |boolean | | |[[Groundwater_(Overlay)|Groundwater Overlay]] |
| |Connected to sewer | | |provides insight into long-term processes of water flow both on the surface and underground |
| |Whether this construction is connected to the sewer. | |
| |} | | |} |
| | <!--==Input Data and Settings== |
| | The calculations performed by the Water Overlay are influenced by many kinds of geographical information present in the project area. For any given location, [[terrain]], [[construction]]s and other features can influence either the initial state of the simulation or how water flows in a given area. |
|
| |
|
| ===Water storage constructions===
| | Furthermore, the Water Overlay features a number of overall settings which can be configured for the hydrological calculations and its results. These settings do not have a geographical or temporal element to them, and are fixed values relevant for the simulation as a whole. |
| Constructions capable of water storage can store some surface water without allowing it to flow back into the rest of the model. Water stored in constructions can not flow out or evaporate away.
| |
| {| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Function value
| |
| ! Description
| |
| |-
| |
| |WATER_STORAGE
| |
| |m³/m²
| |
| |Water storage (m³/m²)
| |
| |How much water this construction can store.
| |
| |}
| |
|
| |
|
| ===Porous constructions===
| | ;[[Hydrologic_features_(Water_Overlay)|Hydrological features]] |
| Some constructions are porous or open, and can allow water to infiltrate into the underground unsaturated zone.
| | :The water system can be enhanced with a number of hydrological features, which can be loaded in as [[area]]s. These hydrological features form special properties or modifications on the hydrological system. See [[Hydrologic_features_(Water_Overlay)|Hydological features]] for a list of supported features. |
| | ;[[Hydraulic structures (Water Overlay)|Hydraulic structures]] |
| | :See [[Hydraulic structures (Water Overlay)|Hydraulic structures]] for the list of supported structures. |
| | ;[[Additional_hydrological_attributes_of_buildings_(Water Overlay)|Hydrological attributes of buildings]] |
| | :Besides the [[building]]s which directly influence the hydrologic model as a [[Hydraulic structures (Water Overlay)|hydraulic structure]], each building may also have attributes which can contribute to the hydrological model in some way. These attributes are stored and used on a grid cell level. This is different from the hydraulic structure attributes, which are stored and used on an object level. For a full list, see [[Additional_hydrological_attributes_of_buildings_(Water Overlay)|Additional hydrological attributes of buildings]]. |
| | ;[[Terrain_attributes_(Water_Overlay)| Hydrological attributes of terrain]] |
| | :[[Terrain]]s in a project have a number of hydrological attributes which can influence the flow of water in a project. Because there is always both surface and underground terrain defined for the entirety of the project area, all cells are affected by all attributes of terrains, unless a building is present with overwriting values. For a full list, see [[Terrain_attributes_(Water_Overlay)| Terrain attributes for the water overlay]]. |
| | ;[[Model_attributes_(Water_Overlay)|Model settings]] |
| | :For a full list, see: [[Model_attributes_(Water_Overlay)|Water Model attributes]] |
|
| |
|
| The speed at which water can infiltrate is dependent on both the infiltration properties of the constructions as well as on the underlying surface terrain. Of the infiltration values of the construction and the surface terrain, the lowest value is used. If either has an infiltration value of 0, water cannot infiltrate into the underground unsaturated zone.
| | ==Troubleshoot, warnings and recommendations== |
| {| class="wikitable"
| | When the Water Overlay is used and calculations take place, there are some problems or points of attention the calculation can run into. Where possible, the Water Overlay will show appropriate warnings when running into any issues. |
| ! Attribute
| | See [[Warning_and_recommendations_(Water_Overlay)|Troubleshoot, warnings and recommendations]]; |
| ! Unit
| | --> |
| ! Function value
| |
| ! Description
| |
| |-
| |
| |GROUND_INFILTRATION_MD
| |
| |m/day
| |
| |Ground infiltration per day (m)
| |
| |The speed at which water can flow vertically from the surface to the underground unsaturated zone. | |
| |}
| |
|
| |
|
| ===Crops and foliage=== | | ==Results== |
| Crops and foliage can draw water from the underground, allowing it to evaporate.
| | With a Water Overlay, a user can generate multiple [[Results_(Water_Overlay)|results]] for a single water simulation. For further information about these outcomes, see also [[Results_(Water_Overlay)|results]] and [[Result type (Water Overlay)|result types]]. |
| {| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Function value
| |
| ! Description
| |
| |-
| |
| |ROOT_DEPTH_M
| |
| |m
| |
| |Depth of plant roots (m)
| |
| |The depth of the roots of this construction, relative to the terrain height at the location of this construction. Water can be drawn from the underground and evaporated if the roots can reach it. | |
| |-
| |
| |WATER_EVAPORATION_FACTOR
| |
| |factor
| |
| |Water evaporation
| |
| |How fast this construction can evaporate water from the underground. The {{inlink|weather}}'s evaporation speed is multiplied by this factor to determine the rate of evaporation. | |
| |}
| |
| Note that when a construction is present in any given location, the values for evaporation will overrule any values set by terrain in the same location. To model underground evaporation without a construction, set these attributes on the applicable terrain type instead.
| |
|
| |
|
| ===Chemical emitters=== | | ==How-to's== |
| Chemical emitters are constructions which produce specific chemicals. The net amount of chemicals a single construction creates is spread out across it's surface. After the chemicals are created, any water flowing through the same location will carry a part of the chemicals with it.
| | * [[How to add and remove an Overlay]] |
| | * [[How to manually configure a Water Overlay|Configure a Water Overlay]] |
| | * [[How to edit an overlay legend|Edit an overlay legend]] |
| | * [[How to add Subsidence (Water Overlay)|Combine with Subsidence Overlay]] |
| | * [[Water Model Limits]] (some basic rules) |
|
| |
|
| In situations where water is absent, chemicals cannot move between cells.
| | ===Features and components=== |
| {| class="wikitable"
| | * [[Hydrological features (Water Overlay)|Hydrological features]] |
| ! Attribute
| | * [[Hydraulic structures (Water Overlay)|Hydraulic structures]] |
| ! Unit
| | * [[How to_manually_configure_a_Water_Overlay|Manual configuration Options]] |
| ! Description
| | * [[Simulation data (Water Overlay)|Simulation data]] |
| ! Default
| |
| |-
| |
| |CHLORIDE
| |
| |x/m²
| |
| |The amount of chloride created per second per m² in this location.
| |
| |0
| |
| |-
| |
| |NITROGEN
| |
| |x/m²
| |
| |The amount of nitrogen created per second per m² in this location.
| |
| |0
| |
| |-
| |
| |PHOSPHORUS
| |
| |x/m² | |
| |The amount of phosphorus created per second per m² in this location. | |
| |0 | |
| |} | |
|
| |
|
| ==Hydrological properties of terrain== | | ===Attributes=== |
| [[Terrain]]s in a project have a number of hydrological properties which can influence the flow of water in a project. The following attributes of terrains have effects on the hydrological model: | | * [[Model attributes (Water Overlay)|Water Module Attributes]] |
| | * [[Hydrological attributes of buildings (Water Overlay)|Hydrological Attributes of Buildings]] |
| | * [[Hydrological attributes of terrains (Water Overlay)|Hydrological Attributes of Terrains]] |
|
| |
|
| ===Water===
| | {{WaterOverlay output nav}} |
| Water terrains are processed by the water model in a specific manner before the simulation is started. For each water terrain in the 3D world, the bottom of the water body is treated as a land surface in the same fashion as dry land. Water is then placed on it on the surface {{inlink|layers|layer}}, up to the level defined by the overlapping {{inlink|Water level area|water area}}'s {{inlink|WATER_LEVEL}} attribute. Terrains not marked as water terrain are not initiated with water.
| | {{Overlay nav}} |
| {| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Terrain type
| |
| ! Description
| |
| |-
| |
| |WATER
| |
| |boolean
| |
| |Surface
| |
| |Whether the specified terrain is a water terrain.
| |
| |}
| |
|
| |
|
| ===Evaporation===
| | [[Category:Water Module]][[Category:Overlays with result types]] |
| Terrains can be configured to draw water from the underground and evaporate it.
| |
| {| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Terrain type
| |
| ! Description
| |
| |-
| |
| |ROOT_DEPTH_M
| |
| |m
| |
| |Surface
| |
| |The depth of the roots of this surface terrain, relative to the surface. Water can be drawn from the underground and evaporated if the roots can reach it.
| |
| |-
| |
| |WATER_EVAPORATION_FACTOR
| |
| |factor
| |
| |Surface
| |
| |How fast this terrain can evaporate water from the underground. The {{inlink|weather}}'s evaporation speed is multiplied by this factor to determine the rate of evaporation.
| |
| |}
| |
| Note that when a construction is present in any given location, the values for evaporation of the construction will overrule any values set by terrain in the same location. This is also true if the construction has its evaporation values set to 0; they will overrule the terrain's values and thus not allow evaporation of underground water to occur.
| |
| | |
| Also note that the groundwater level reduction is inversely proportional to the {{inlink|WATER_STORAGE_PERCENTAGE}}, as the contribution of a given volume of water to the groundwater level increases as the capacity for water storage in the underground layer decreases.
| |
| | |
| ===Infiltration and storage===
| |
| Based on the properties of the terrain, water may infiltrate into the underground water system.
| |
| | |
| The speed at which water can infiltrate from the surface to the underground unsaturated zone is dependent on both the infiltration properties of the surface terrain, as well as any construction in that location, if present. Of the infiltration values of the construction and the surface terrain, the lowest value is used. If either has an infiltration value of 0, water cannot infiltrate into the underground unsaturated zone.
| |
| <!--{| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Terrain type
| |
| ! Description
| |
| |-
| |
| |GROUND_INFILTRATION_MD
| |
| |m/day
| |
| |Surface
| |
| |The speed at which water can flow vertically from the surface to the underground unsaturated zone.
| |
| |-
| |
| |GROUND_INFILTRATION_MD
| |
| |m/day
| |
| |Underground
| |
| |The speed at which water can flow vertically from the underground unsaturated zone to the underground saturated zone, and horizontally through across the saturated zone.
| |
| |-
| |
| |WATER_STORAGE_PERCENTAGE
| |
| |percentage
| |
| |Underground
| |
| |The percentage of the underground volume which can be filled with water. A lower percentage means the underground will be able to store less water, and the saturated zone will rise higher with the same amount of water in the underground layer.
| |
| |}-->
| |
| | |
| ==Result types==
| |
| Each Water Overlay is a [[grid overlay]] showing results on the surface (flooding), sub-surface (groundwater), open water and sewer system. The following results are produced:
| |
| {| class="wikitable"
| |
| ! Result type
| |
| ! Unit
| |
| ! Displayed value
| |
| ! Description
| |
| |-
| |
| |BASE_TYPES
| |
| |Nominal value
| |
| |Start of simulation
| |
| |Categorization of the individual cells based on how they are processed by the water model, displaying which cells are considered to be specific features.
| |
| |-
| |
| |CHLORIDE
| |
| |x/m²
| |
| |Value at current timestep
| |
| |The amount of chloride present. The value is the sum of the quantities on the surface, and the underground.
| |
| |-
| |
| |DIRECTION
| |
| |Degrees
| |
| |Value at current timestep
| |
| |The direction in which water is flowing.
| |
| |-
| |
| |EVAPORATED
| |
| |m (mm)¹
| |
| |Total at current timestep
| |
| |The amount of water that has evaporated. The value is the sum of the quantities evaporated from the surface and the underground.
| |
| |-
| |
| |GPU OVERVIEW
| |
| |nominal value
| |
| |Start of simulation
| |
| |Shows which GPU cluster calculated which part of the overlay.
| |
| |-
| |
| |IMPACTED_BUILDINGS
| |
| |nominal value
| |
| |Maximum at current timestep
| |
| |Constructions impacted by excess water. Constructions are considered impacted when the construction itself or an adjacent cell contains more water on the surface than configured in {{inlink|IMPACT_FLOOD_TRESHOLD_M}}.
| |
| 0: Construction is not impacted
| |
| 1: Construction is impacted, and the critical [[function value]] is set to 0.
| |
| 2: Construction is impacted, and the critical [[function value]] is set to 1.
| |
| |-
| |
| |LAST SPEED
| |
| |m/s
| |
| |
| |
| |The speed of the flooding at the last calculated timestep
| |
| |-
| |
| |MAX SPEED
| |
| |m/s
| |
| |
| |
| |The maximum speed of the flooding of all the calculated timesteps
| |
| |-
| |
| |NITROGEN
| |
| |
| |
| |
| |
| |''Description will be added when available''
| |
| |-
| |
| |PHOSPHORUS
| |
| |
| |
| |
| |
| |''Description will be added when available''
| |
| |-
| |
| |SEWER_LAST_VALUE
| |
| |m (mm)¹
| |
| |
| |
| |The amount of water in the sewer storage at the last calculated timestep
| |
| |-
| |
| |SEWER_MAX_VALUE
| |
| |m (mm)¹
| |
| |
| |
| |The maximum amount of water in the sewer storage of all the calculated timesteps
| |
| |-
| |
| |SURFACE_DURATION
| |
| |s (min)¹
| |
| |
| |
| |The amount of time the water depth in a cell exceeds the value set in the overlay attribute value SHOW_DURATION_FLOOD_LEVEL_M
| |
| |-
| |
| |SURFACE_FLOW
| |
| |m3/m2
| |
| |
| |
| |Total volume of water passed a grid-cell, scaled by the cell surface (grid cell-size^2)
| |
| |-
| |
| |SURFACE_LAST_VALUE
| |
| |m (mm)¹
| |
| |
| |
| |The water depth at the last calculated timestep
| |
| |-
| |
| |SURFACE_MAX_VALUE
| |
| |m (mm)¹
| |
| |
| |
| |The maximum water depth of all the calculated timesteps
| |
| |-
| |
| |UNDERGROUND_FLOW
| |
| |m³/m²
| |
| |
| |
| |Total infiltration amount from the surface to groundwater
| |
| |-
| |
| |UNDERGROUND_LAST_STORAGE
| |
| |
| |
| |
| |
| |The (effective) amount of water in the underground unsaturated zone at the end of the last calculated timestep
| |
| |-
| |
| |UNDERGROUND_LAST_VALUE
| |
| |m (mm)¹
| |
| |
| |
| |The amount by which the groundwater table has risen above the initial groundwater level at the last calculated timestep
| |
| |-
| |
| |UNDERGROUND_MAX_STORAGE
| |
| |
| |
| |
| |
| |The maximum (effective) amount of water in the underground unsaturated zone across all calculated timesteps
| |
| |-
| |
| |UNDERGROUND_MAX_VALUE
| |
| |m (mm)¹
| |
| |
| |
| |The maximum amount by which the groundwater table has risen above the initial groundwater of all the calculated timesteps
| |
| |-
| |
| |UNDERGROUND WATERTABLE
| |
| |m + [[datum]]
| |
| |
| |
| |The groundwater level, relative to [[datum]], at the last calculated timestep.
| |
| |-
| |
| |WATER_STRESS
| |
| |m (mm)¹
| |
| |
| |
| |The maximum water depth of all the calculated timesteps (almost the same as the SURFACE_MAX_VALUE, but if the terrain type is water only a water depth is shown if the depth exceeds the overlay attribute value ALLOWED_WATER_INCREASE_M)
| |
| |}
| |
| | |
| ¹ the units between () are as displayed in the 3D client. If exported to GeoTiff the SI-convention is used: meters (m) and seconds (s).
| |
| | |
| ==General Tab==
| |
| [[File:General_tab.JPG|250px|right|The geberal tab of the Water Overlays.]]
| |
| The General Tab can be found at the panel on the right side, when selecting a Water Overlay. In this tab several settings can be adjusted.
| |
| | |
| ===Calculation Preference===
| |
| Here you can manipulate the computation time step by choosing between the option SPEED, AVERAGE and ACCURACY. The computational timesteps will be set according to the Courant criterion:
| |
| | |
| Δt = Δx /u<sub>max</sub>
| |
| | |
| where:
| |
| * Δt = computational timestep
| |
| * Δx = grid cell size
| |
| * u<sub>max</sub> = max velocity, assumed 2.5 (SPEED), 5 (AVERAGE) and 10 (ACCURACY) m3/s respectively
| |
| | |
| ===Grid cell size===
| |
| The {{software}} computes flow equations over a rectangular cartesian grid, the grid cell size can be set by clicking on Change Grid.
| |
| After the grid cell size is changed, the Overlay is immediately being recalculated.
| |
| Note: if you choose a smaller grid cell size, both the amount of time steps (see Calculation Preference) and amount of computational cells increase.
| |
| | |
| ===Refresh Grid===
| |
| By Refreshing the grid, the Overlay is recalculated. This may take some time, depending on the grid cell size, the size of your project and the calcualtion preference.
| |
| Below some use cases when to use Refresh Grid:
| |
| * when you have changed a setting in the Configuration Wizard, but not clicked on the Finish button of the wizard.
| |
| * when you change the Result type or calculcation preference in the General tab
| |
| * when you change the legend in the Legend tab
| |
| * when you change the keys in the Keys tab
| |
| * when you change the attrbutes of the Overlay in the Attributes tab
| |
| | |
| ===Export Grid File===
| |
| You can export the current result type as either a GeoTiff (binary file/bitmap image can be opened in a GIS or in an image viewer) or ASCII (text file, can also be opened in a GIS but is also readable in a text editor) file.
| |
| Also, it is possible to export the difference result type of the current and maquette situation.
| |
| | |
| ===Save Overlay result===
| |
| With this option you can create a duplicate inactive copy of the current overlay. This is noticeable in the Overlays panel on the left side of the screen. The duplicated overlay will have (inactive copy) behind the overlay name and is greyed out. This copy is not being recalculated when changing settings in the original duplicated overlay. When checking the checkbox: active in simulation, the copy becomes active again and can be recalculated. Also the overlay name is again in black and not grayed out anymore.
| |
| | |
| ===Show Water Balance===
| |
| The Water Balance panel shows the in- and outflow of water in m3. The Water Balance panel is also visible when clicking on the Debug info (see below).
| |
| The water balance is made up of the following components (depending on what is in the project):
| |
| * Land surface: amount of water on the land surface after simulation (m3)
| |
| * Water surface: amount of water stored on water cells after simulation (m3)
| |
| * Building storage: amount of water stored in building storage (m3)
| |
| * Sewer storage: amount of water stored in sewers after simulation (m3)
| |
| * Underground storage: amount of water stored in the sub-soil after simulation (m3)
| |
| * Evaporated: amount of water evaporated after simulation (m3)
| |
| * Outlet: amount of water extracted from the model during the simulation via outlets of water areas or sewer pumps (m3).
| |
| | |
| ===Warnings===
| |
| When the grid cell size is too large in combination with the project size, a warning pops up. This means that calculated results are not accurate. The solution to this is to reduce the grid cell size.
| |
| | |
| ===Debug Info===
| |
| The debug info contains the following information:
| |
| * Rain: the amount of rainfall (mm) in the duration of the rainfall event (hours)
| |
| * Total Simulation: the simulation period (hours)
| |
| * Cells: The dimensions of the simulation: the amount of computational cells and the amount of time steps (cycles)
| |
| * Water areas:
| |
| * Weir flow: the amount of water flown over weirs during simulation (m3)
| |
| * Sewer overflow: the amount of water flown over sewer overflows during simulation (m3)
| |
| * GPU time: the computation time on GPU (seconds)
| |
| * Volume: total volume of the in- and outflow of water in the model.
| |
| If you click on the Debug Info the Water Balance panel pops up.
| |
| | |
| ==Keys tab==
| |
| The tab Keys refers to the settings for the water system (areas and constructions) that are adjusted by following the configuration wizard in the General tab. It is therefore generally not needed to change the keys in this tab, as most of the keys are adjusted via the configuration wizard. However, below an explanation of the Keys for areas and buildings.
| |
| | |
| {| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Description
| |
| |-
| |
| |Water Level
| |
| |m + datum
| |
| |initial water level, relative to datum, for all water cells in a water area
| |
| |-
| |
| |Outlet
| |
| |m3/s
| |
| |water abstraction for all water cells in a water area
| |
| |-
| |
| |Outlet level
| |
| |m + datum
| |
| |initial water level, relative to datum, for all water cells in an outlet area (breach for example)
| |
| |-
| |
| |Outlet capacity
| |
| |m3
| |
| |maximum amount of water that can be used for the outlet
| |
| |-
| |
| |Sewer Storage
| |
| |m
| |
| |available storage in sewers at the start of simulation in a sewer area
| |
| |-
| |
| |Sewer Pump Speed
| |
| |m3/s
| |
| |sewer water abstraction for all cells in a sewer area
| |
| |-
| |
| |Breach Floor
| |
| |mNAP
| |
| |Modified terrain height, to simulate a breach in a levee.
| |
| |-
| |
| |Inundation level
| |
| |mNAP
| |
| |Initial water height, to simulate water present at the start of the simulation.
| |
| |}
| |
| | |
| Keys referring to constructions (building attributes)
| |
| {| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Description
| |
| |-
| |
| |Weir Height
| |
| |m + datum
| |
| |weir crest level
| |
| |-
| |
| |Weir Output
| |
| |m3/s
| |
| |The amount of water that flows through a weir/culvert
| |
| |-
| |
| |Weir Coefficient
| |
| |
| |
| |linear weir coefficient for accounting discharge & contraction losses
| |
| |-
| |
| |Culvert Speed
| |
| |m3/s
| |
| |the discharge capacity of a culvert
| |
| |-
| |
| |Pump Speed
| |
| |m3/s
| |
| |the capacity of a pump
| |
| |-
| |
| |Sewer Overflow Height
| |
| |m + datum
| |
| |the height of a crest of a sewer overflow
| |
| |-
| |
| |Sewer Overflow Speed
| |
| |m3/s
| |
| |the discharge capacity of a sewer overflow
| |
| |-
| |
| |Chloride
| |
| |x/m2
| |
| |Amount* of chloride which is created per second, per m² of construction with this attribute.
| |
| |-
| |
| |Nitrogen
| |
| |x/m2
| |
| |Amount* of nitrogen which is created per second, per m² of construction with this attribute.
| |
| |-
| |
| |Phosphorus
| |
| |x/m2
| |
| |Amount* of phosphorus which is created per second, per m² of construction with this attribute.
| |
| |-
| |
| |}
| |
| <nowiki>*</nowiki> The unit of the substances is left incomplete, as the project creator is free to set their own unit for quantities of substances.
| |
| | |
| ==Attributes tab==
| |
| This tab shows the attributes of result types that can be adjusted. These attributes can also be adjusted in the configuration wizard in step 5 in the General tab. It is therefore generally not needed to change the attributes here. However, below an overview of the Overlay Attributes.
| |
| | |
| {| class="wikitable"
| |
| ! Attribute
| |
| ! Unit
| |
| ! Description
| |
| |-
| |
| |ALLOWED_WATER_INCREASE_M
| |
| |m
| |
| |increment by which the water level on a water cell is allowed to increase before the depth is shown in the WATER_STRESS result type
| |
| |-
| |
| |AVG_SURFACE_WATER
| |
| |
| |
| |''Description wil be added''
| |
| |-
| |
| |DESIGN_FLOOD_ELEVATION_M
| |
| |m
| |
| |Constructions in the 3D world are assumed to have at most this height compared to the surface of the terrain. Greater values can create a more accurate model but will impact performance.
| |
| |-
| |
| |GROUND_BOTTOM_DISTANCE_M
| |
| |m
| |
| |Assumed distance under the terrain surface where the soil becomes impenetrable for water. The groundwater level cannot go below this depth, relative to the surface. The maximum amount of water that can be stored underground is equal to this attribute multiplied by the local terrain's {{inlink|WATER_STORAGE_PERCENTAGE}}.
| |
| |-
| |
| |GROUND_WATER
| |
| |
| |
| |''Description wil be added''
| |
| |-
| |
| |IMPACT_FLOOD_THRESHOLD_M
| |
| |m
| |
| |maximum waterdepth on a cell which touches the building where after the building is assumed impacted, visualized in the IMPACTED_BUILDINGS result type
| |
| |-
| |
| |MAX_SPEED_MS
| |
| |
| |
| |Maximum speed at which water is allowed to flow. As the maximum speed is set higher, the time per step of the calculation is reduced, increasing total time for the calculation to complete.
| |
| |-
| |
| |MIN_SLOPE
| |
| |
| |
| |slope whereunder the pressure slope is assumed 0
| |
| |-
| |
| |SEWER_OVERFLOW_THRESHOLD
| |
| |
| |
| |fraction of storage whereafter sewer overflows take place
| |
| |-
| |
| |SHOW_DURATION_FLOOD_LEVEL_M
| |
| |m
| |
| |threshold value of the amount of water on a grid cell that is used for the SURFACE_DURATION result type
| |
| |-
| |
| |SUPERGRID
| |
| |
| |
| |This marks an experimental feature which is currently under development and may result in unexpected behavior when activated.
| |
| |-
| |
| |SURFACE_WATER_EVAPORATION_FACTOR
| |
| |
| |
| |''Description wil be added''
| |
| |-
| |
| |TIMEFRAMES
| |
| |
| |
| |the number of intermediate (overlay) results you would like to see of the calculation. A timeframe is not the same as a timestep. A timeframe is an intermediate (overlay) result and can contain already a number of timesteps. The number of timesteps is based on the grid cell size and the speed of the flooding (see for more information the [[Flooding_(Overlay)#Flooding_Model|Courant number]]).
| |
| |}
| |
