Time sequence (Water Overlay)

In the Water Overlay, a number of elements can be configured as a time sequence rather than a single value. This means that during the simulation, the value used for calculations changes over time.

Time sequences can be loaded in via two methods: directly as attributes of imported Geo data, or by importing a CSV file via the configuration wizard.

Structure of a time sequence

Time sequences are stored in project data in the form of attribute arrays. It consists of a sequence of pairs of a time and a value to use for that time. A maximum of 100 values is used, interpreted as 50 individual pairs of a time and a value.

Conceptually, a time sequence is always structures as follows:

Time (seconds)	Value
3600	0.03
7200	0
9000	0.03
10800	0.06

The unit for time is stored in seconds. The unit for the value is dependant on the element for which the time sequence is used.

Depending on the type of element you wish to configure using a time sequence, the interpretation of a time sequence can differ.

Definition by end

Up until specific times, a certain value is applicable.

Rainfall and evaporation use an interpretation by which the times indicate up to when the value is used.

Definition by start

From certain times onward, a certain value is applicable.

The speeds of hydraulic structures use an interpretation by which the times indicate from when onward a value is used.

Interpolated

The applicable value is interpolated.

Heights and target water levels of breaches and hydraulic structures use an interpretation by which the used value is interpolated based on the current time in the simulation, the preceding and upcoming defined time in the time sequence, and the associated value.

Structure of data

There are multiple methods to load a time sequence in the Tygron Platform, and depending on the method the data will be structured slightly different to load it in.

CSV

A CSV file to import a time sequence should look as follows:

3600,0.03
7200,0
9000,0.03
10800,0.06

On each row, the first value is the time, and the second value is the value to be used.

Attribute

When importing a time sequence in an attribute while importing geo data, the attribute should contain a list of values which looks as follows:

[3600, 0.03, 7200, 0, 9000, 0.03, 10800, 0.06]

The first value is the time for the first time-value pair, the second value is the value of that pair. The third value is the time for the second time-value pair, and so forth.

Notes

• When importing a CSV for a time sequence, it's possible to indicate whether the time is in seconds, minutes, or hours. The Tygron Platform then automatically converts the time to the correct data for the model.
• When exporting data which has a time sequence for an attribute, it is formatted in the same structure which can be used to load it back in as an attribute.

See also

• https://www.tygron.com/en/2020/04/20/water-module-time-sequence/