View source for How to trace water through project area (Water Overlay)

To track water in a hydrological system, i.e. find where water from a specific point flows to, it is possible to artificially add a chemical emitter in the water system. Any water passing through that building will pick up the chemical. By having a result type added which highlights that chemical, the flow of the water can be tracked quite accurately.

For the purposes of this scenario, a simple hydrological model will be assumed, although the same technique can be used for [[Water Overlay#breach|breach]]es and other calamitous scenarios. We will also assume we can use the [[Tracer_ABCD_(Water_Overlay)|TRACER_A]] particle as our "tracker". We will track any water flowing through a specific location.

''If TRACER_A is already in use for another purpose, any other [[Tracer ABCD (Water Overlay)|tracer]] can be used. At least one tracer should be unused in order to fulfill this use-case. The instructions on this page will assume TRACER_A.''

==Requirements==
Before implementing this use-case, make sure you have a [[Basic water model use case (Water Overlay)|basic water model]] set up. For the specified scenario, the [[Groundwater_(Overlay)|ground overlay]] is recommended, though any variant will work.

Also ensure the following in your project, if possible:
* The hydrological system has some input which allows or causes water flow. An [[Inlet (Water Overlay)|inlet]], a [[Pump (Water Overlay)|pump]], or even an [[elevation model|incline]] would be sufficient.
* The hydrological system has a [[Tracer a result type (Water Overlay)|TRACER_A]] result type, either as main result or as a child result type.
* The simulation is set up to output a reasonable amount of timeframes. For most simulation durations, 25 to 50 timeframes will suffice.

==Steps==
The use-case can be implemented through the following steps.
{{Editor steps|title=set up water flow tracking
|Configure a [[Basic_water_model_use_case_(Water_Overlay)|base hydrological system]].
|Find the location, from where you wish to track the water, using the [[3D Visualization]].
|Add an [[buildings#Editing buildings|above-ground building]] to that location. A building with the function "reeds" often works best, as it can be placed both on land and in water.
|Add the "TRACER_A" attribute to the added building, with a value of "1". See [[How_to_add_and_remove_an_Attribute|How to add and remove an Attribute]]
|Ensure the overlay is [[Grid_Overlay#Grid recalculation|recalculated]].
|Inspect the "Tracer A" result overlay. The greater the concentration of the tracer in any given location, the more water from the inlet has flowed there.
|Select the "play" option in the overlay's legend. The animation will show the flow of the water from the indicated location.
}}

{{article end
|notes=
*To track water from different locations or sources ([[Inlet (Water Overlay)|inlet]]s, or other buildings), add the chemical attribute to the building of which you wish to track the water.

*To track water from different sources collectively, each source can be configured with the same chemical attribute. (In the specified example, multiple sources can be provided with the TRACER_A attribute.)

*To track water from different sources with the ability to differentiate between what water came from which specific source, each source can be given a different [[Tracer ABCD (Water Overlay)|tracer]] to produce.
|seealso=
*[[Tracer a result type (Water Overlay)]]
*[[Tracer ABCD (Water Overlay)]]
}}
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[[Category:How-to's]]