Description A dfs0 is a type of timeseries data file used across DHI's software suite, which has no spatial dimensions. It stores timeseries data in a binary format and is typically used as an input to a model and also an output of timeseries. A dfs0 file can store multiple items (e.g. Monitored water levels at multiple gauges) as long as the time axis are identical.
This article describes the details of properties defined in a dfs0 file. While some properties are specific to a dfs0, item types and units are common for other timeseries files such as dfs1, dfs2, dfs3, and dfsu.
To view and edit Properties, go to Edit>Properties. See Fig. 1.
Fig. 1 – Open timeseries Properties in a dfs0
Properties
#01 Time Axis Type
The majority of MIKE models require either Equidistant Calendar Axis or Non-Equidistant Calendar Axis where you need to define calendar date and time. Some models like SWMM, EPANET in MIKE+ use a Relative axis type where the time axis is defined as elapsed time from the start of timeseries.
When the Equidistant axis is selected, you need to specify the start Date and Time and Time step. If timeseries are not saved at a fixed interval, you can use Non-Equidistant Calendar Axis, with which you can specify the date time of data for each timestep. Ensure that the time axis is always increasing.
#02 – No. of Timesteps
This determines the total number of timesteps.
#03 – Delete Value
A missing value in the timeseries, which looks blank in the table, is actually stored in a file as the delete value. Usually, you do not need to change these values.
#04 – Item information: Name
This is a typically user-defined name. Some processing tools and software may require the Items to have specific Names to recognize .
#05 – Item information: Item Type
Item type indicates the type of data e.g. Water Level, Rainfall, and Wave Direction etc, which also determines the dimensions of the unit. Choose the Item Type from the list. You can start typing the first few letters (e.g. “WAT” for water level) to jump to the item you are looking for.
You may notice that there are a few items called similar names such as Precipitation, Precipitation Rate, Rainfall and Rainfall Intensity. These variety originates from the software development history. Each software and module require a particular Item Type. You can find out the required item type under “Constraints Info” tab, when you browse a dfs0 file in a model setup. See Fig. 2.
Fig. 2 – Constraints info
#06 – Item information: Unit
When you select Item Type, the list of units is automatically updated. Select the relevant unit.
#07 – Item information: TS type
TS type defines how the table of values should be interpreted temporally. Some of the engines automatically assumes the TS type regardless of what you specify in a dfs0 file. Check what TS type is required for each software and module. Note that some simulation engines automatically assumes all data to be in a certain type of TS type regardless of the TS type specified in a dfs0. See Fig. 3.
Fig. 3 TS types in a dfs0 file
Instantaneous:
Values are representative at a specific instant. Typically, water Level, groundwater pressure, discharge gauged data and outputs from a hydrodynamic models such as wind velocity, discharge, water depth are stored as Instantaneous values. Between the given timesteps, the engine linearly interpolates values. See Fig. 4.
Fig. 4 Instantaneous timeseries
Accumulated
Values are representative of one successive accumulation over time and always relative to the start of the event.
This type of TS type is rarely used as a model input.
Step Accumulated
Step accumulated values are representative of an accumulation over one timestep between the previous time step and the current time step. Typical examples are rainfall or precipitation in the unit of mm. See Fig. 5.
Fig. 5 Step-Accumulated timeseries
Mean Step Accumulated
Values are representative of an average value over a timespan between the previous timestep and the current time step. A typical example is Precipitation Intensity in the intensity unit such as mm/h or mm/d. See Fig. 6.
Fig. 6 Mean Step Accumulated timeseries
Reverse Mean Step Accumulated
Values are representative of an average value over a timespan between the current timestep and the next time step. It's not often used in a hydrodynamic model but often used for a water allocation planning like MIKE HYDRO Basin. See Fig. 7.
Fig. 7 Reverse Mean Step Accumulated timeseries
Additional notes
Item types and units are common for other timeseries files such as dfs1, dfs2, dfs3, and dfsu.
