Create a new dfs0 file

When creating a new dfs0 file using the button for external files, a dialogue window will be opened. This dialogue is used in different situations for creat­ing a time series (dfs0) file or a table file. The model automatically detects the type of file needed and adjusts the dialogue accordingly.

Create a new time series file

To create a new time series file, the following properties must be specified:

·         Filename: You may either browse for or manually type the name and location of the time series file.

·         Period: You may choose the start and end date of the time series using the date-time pickers. The default values will be the simulation period for your setup.

·         Time axis type: You may choose among non-equidistant calendar axis type and equidistant calendar axis type. For the non-equidistant type, the interval between data values may vary. For the equidistant type, equal time spacing between each time step will be enforced.

·         Time series interval: The time series interval is the size of the time step.

Example: Specifying the following:

–         Start date: 01-01-1980

–         End date: 31-12-1981

–         Time series interval: 1 month

will cause a time series file with 12 time steps to be created.

·         Items: Depending on the context in which the file is being created, the file will be created with one or more data items.

·         Item name: The name of the data item

·         Uniform value: All the time series files which are created with this dia­logue will contain the value specified here in all time steps (uniform value). To create files with values varying over time (non-uniform), first create a uniform value time series and then edit it in the time series edi­tor.

·         Time series type: Contains information on how the data values are interpreted. The possible types are:

–         Instantaneous: Means that the values are representative at one precise instant. For example, a measured water level is an instanta­neous value. Linear variation between time steps is assumed.

–         Accumulated: Means that the values are representative of one suc­cessive accumulation over time from the start of the event (start time specified) to the current time step (.i.e. accumulated over the entire series). For example, the rainfall is accumulated over the year if we have recorded monthly rainfall values. Linear variation between time steps is assumed.

–         Step Accumulated: Means values are representative of an accu­mulation over a time step. For example, rainfall is a step-accumu­lated value if the rain depth is recorded at different intervals. Values represent the time span between the previous time step and the cur­rent time step.

Example: Rainfall measurement is started at 10:00:00. At 11:00:00 someone picks the recipient, registers the value of 10 mm and emp­ties the recipient. At 12:00:00 the same process is repeated but with a value of 15 mm and so on. Thus, the time series will have the value of 10 mm at time step 11:00:00 and the value 15 mm at 12:00:00 etc.

–         Mean step accumulated: Means that values are representative of an average accumulation per time step. For example, the average rain rate is a mean step accumulated value. Values represent the time span between the previous time step and the current time step.

–         Reverse mean step accumulated: Is equal to Mean Step Accumu­lated type, but values represent the time span between the current time step and the next time step. Used for forecasting purposes.

·         Item type: The type of data item. The drop-down list can be used to choose one of the possible item types. The choices available will depend on the context.

·         Item Unit: The unit type of the data item. The drop-down list can be used to choose one of the possible unit types. The choices available will depend on the item type.

Note: For more information on time serie types, item types and units see the ‘DFS File User Guide’ in the MIKE Zero Documentation.

Create a new table file

To create a new table file the following properties must be specified:

·         Filename: You may either browse for or manually type the name and location of the time series file.

·         No. of timesteps: This defines the number of rows in the table (or the number of x-axis points on a curve).

·         X-axis unit: The x-axis unit can be selected from the drop-down menu.

·         Items: Depending on the context in which the file is being created, the file will be created with one or more data items.

·         Item name: The name of the data item.

·         Values: Here the pair-wise values of the x-axis and the item are entered. The table file can consecutively be edited in the time series editor.

·         Value series type: Contains information on how the data values are interpreted. The possible types are the same as for a dfs0 file see sec­tion Create a new time series file (p. 38).

·         Item type: The type of data item. The drop-down list can be used to choose one of the possible item types. The choices available will depend on the context.

·         Item Unit: The unit type of the data item. The drop-down list can be used to choose one of the possible unit types. The choices available will depend on the item type.

Note: For more information on time serie types, item types and units see the ‘DFS File User Guide’ in the MIKE Zero Documentation.