Creating hyetographs and other time series from the TIN datasets is one of the basic functions of HEC-MetVue. To create a time series, select 'File->Save/Create Time Series…' from the main menu or press the icon  on the toolbar. These tools are enabled when a Map Window has the focus, contains one or more TIN datasets, and contains one or more active polygon shapefiles. The table below provides a description of features available in the Compute Time Series dialog.

When creating time series, it is advantageous to use multiple aggregated images that are temporally resolute enough to give a reasonable hyetograph. For example, if using a single TIN dataset representing a 24 hour time period, the program will still allow for the generation of hourly time series for the polygons, however, each of the hyetograph ordinates for any particular polygon will be the same; 1/24 of the computed total since that is the temporal resolution of the original data. A better solution would be to use twenty-four 1 hour TINs aggregated together. Following any edit operations and data cleanup, the generated hyetographs would maintain the temporal resolution of the original data. Any edits performed on the data are back applied to the original images making up the aggregate prior to creation of the time series.

When the program generates polygon averages, it does so for each TIN composing the aggregated TIN and, for each polygon it creates a mass curve over time based on these base images. The time intervals of the TIN and that of the desired hyetographs are independent of each other. It is even possible to generate hyetographs from irregular TIN image data if desired since the actual values are ascertained directly from the temporal mass curve for the polygon. From these mass curves, HEC-MetVue then determines the appropriate values at the selected intervals along each polygon curve.

Item

Description

1 

The time interval to use for creating time series.

 2

The time interval units to use for creating time series.

 3

Displays the time zone which will be used when saving the time series. Press this button to change the time zone.

 4

Check this to write the time series to DSS.

 5

The DSS file to write the time series data to.

 6

Use this to brows the file system to locate the desired DSS file to use.

 7

If 'Entire timespan' is selected, the time span covered by the aggregate TIN will be used to create the time series. Selecting 'Missing timespan only' will inspect the hyetographs in DSS and determine the portion of the time span that is undefined and use that to compute and write/extend the time series. This option is an optimization to speed computations for certain operations such as forecasting where the TIN data is simply covering a new time span but each of the existing discrete TIN datasets previously used are unchanged. If the aggregate TIN is edited in any way the 'Entire timespan' option should be selected.

 8

The basin average computation method is used to select the area to compute the polygon averages. It is analogous to the properties options on the Layer Settings Tab, Polygon/Basin Averages Settings section. If set to 'TIN-Polygon Intersection' it will generate hyetographs based on the area common to both the polygon and the defined area of the TIN. When set to 'Basin Polygon' the hyetograph will be based on the polygon area only.

 9

This is used to specify the path to use to write to DSS. The A and F DSS pathname parts can be defined in the basin average shapefile DBF file using the column names DSSA and DSSF respectively. Checking 'Override A' or 'Override F' will instruct the program to ignore the definitions in the shapefile DBF file and use the displayed values instead. The DSS B part is defined by the name of the shapefile DBF column. If more than one basin average shapefile is being used, the column names that are present in both shapefiles will be shown in the dropdown using the normal black text. Columns that do not appear in all the shapefiles will be shown in a lighter gray color to indicate the discrepancy. If a column is selected that is not in all the shapefiles, the program will attempt to find a column named 'NAME', 'LOCATION', 'ID', 'DSSB', 'STATION' in that order. If this fails, the program will form a B pathname part using the file identifier along with the segment number within the shapefile to generate a unique name. Any conflict that causes multiple subareas to result in the same DSS pathname will cause an error message to be displayed.

 10

Select this to write the time series to a text file.

 11

This specifies the text file to write the time series data to.

 12

Select this to browse the file system to locate the output text file.

 13

Select this to have the time series data appended to the output file. When not selected, the computed time series will overwrite the contents of the output file.

 14

Select this to write the results to the screen. The results will be essentially the same as what is written to the file but the formats may be modified slightly for readability.

 15

This specifies the format to write the data to the text file &/or screen. The most common option is to use the Tabular format. The Legacy Forecast format is to help in the transition to HEC-MetVue and will likely be removed in future versions of the program. The SHEF format is not yet implemented.

 16

Currently not implemented. Intended to give additional control over the output formatting in future versions of the program.

 17

If this option is selected, prior to saving the time series a validation editor will be displayed which allows the modification of individual time series.

 18

This choice allows the data to be viewed and edited in either the display time zone or the storage time zone.

 19

The validation editor displays the data in either a tree view where sub hourly ordinals are wrapped up into hourly, hourly to daily, and so on. This value specifies in hours and minutes 'hhmm' the start time of day to use for the daily rollup. For example, specifying 0700 would cause the daily rollup to go from 0700-0700 instead of midnight to midnight.

 20

Confirm.

 21

Cancel.