Rain gages supply rainfall data for the selected location in the study area. The rainfall data can either be user-defined or described in an external file. Rain gages are part of the project and can be shared by multiple meteorologic models.
In GeoHECRAS software, the user can define the rain gage data using the Rain Gage Data command. The defined rain gage data can later be used to define the precipitation point data that are then interpolated over the raster grid. Refer to this article in our knowledge base to learn how precipitation point data are interpolated over the raster grid.
Follow the steps below to use the Rain Gage Data command:
- From the Input ribbon menu, click the Meteorology Data dropdown menu and select the Rain Gage Data command.
- The Rain Gage Data dialog box will be displayed, as shown below.
The following sections describe how to use the Rain Gage Data command and interact with the above dialog box.
Selecting Rain Gages
The Select Rain Gage section allows the user to select the rain gage for which rain gage data will be defined. In this section, the user can create, delete, or copy existing rain gage data to a new rain gage. In addition, the user can navigate between rain gages and enter a description for each rain gage.
The following entries are provided in this section:
- Rain gage ID
This dropdown combo box lists all the rain gages that are defined in the current scenario. Click on the edit option (i.e., pencil icon) to edit the rain gage ID. The user can navigate between the previous and next rain gage using the Up and Down arrow buttons. Note that the Up and Down arrow buttons will be disabled (i.e., grayed out) if the current scenario contains a single rain gage.
- Description
This optional text field allows the user to enter additional information that describes the selected rain gage.
- New
The [New] button allows the user to create a new rain gage on the Map View. The ID of every newly created rain gage must be unique.
- Copy
The [Copy] button allows the user to copy an existing rain gage along with its associated data to a new rain gage. The software automatically provides a unique ID to the copied rain gage.
- Delete
The [Delete] button allows the user to delete the selected rain gage from the current scenario.
Rain Gage Location
This section allows the user to provide a precise description of the rain gage’s location. The location is specified for each gage in terms of latitude and longitude. The latitude and longitude can be entered in decimal degrees in the Latitude and Longitude fields, respectively. Upon entering the latitude and longitude, the software will provide the location’s physical address in the Location read-only field. Alternatively, the user can click the [Pick] button to pick the location interactively from the Map View. The software will then display the physical address, longitude, and latitude values for the selected location in the respective fields. The user can click the [Clear] button to cancel the previous selection and redo the entire process.
Constant Precipitation Data
This section allows the user to define a constant precipitation rate. Click the [Retrieve Data] button to retrieve the rainfall data using the Lookup Rainfall Intensity dialog box. By default, the radio button on the Constant Precipitation Data section is selected. This section is disabled (i.e., grayed out) if either the DSS Data or Time Series Data radio button is selected. Refer to this article in our knowledge base to learn more about the Lookup Rainfall Intensity dialog box.
DSS Data
This section allows the user to select a DSS data file to define the rain gage time series data. Select the radio button on the DSS Data section to enable the content of this section. Otherwise, this section is disabled (i.e., grayed out).
The following parameters are provided in this section:
- DSS file
This entry denotes the file directory path to the DSS data file. Clicking on the [Select] button allows the user to select the directory path and data path using the DSS Data File & Path dialog box. Refer to this article in our knowledge base to learn more about the DSS Data File & Path dialog box.
- DSS path
This entry denotes the data path within the DSS data file, which contains the rain gage data.
Time Series Data
This section allows the user to manually enter time series data for the selected element. Select the radio button on the Time-Series Data section to enable the content of this section. Otherwise, this section is disabled (i.e., grayed out).
The following parameters are provided in this section:
- Select control
This dropdown combo box is used to define the control data set to use. The following options are available:- Manual date and time – This option is used to define precipitation time series data for irregular time intervals.
- Manual simulation time – This option is used to define precipitation time series data for irregular time intervals.
- Regular Interval (default) – This option is used to define precipitation time series data for regular, fixed-time intervals.
- Data type
This dropdown combo box is used to define the type of data that is to be entered. The following options are available:- PER-AVER
- PER-CUM
- INST-VAL
- Precipitation data starting date time
This subsection is used to select the simulation date and the start time to define the time series data. This subsection is enabled only when the Regular interval is selected in the Select control dropdown combo box. Otherwise, this subsection is disabled (i.e., grayed out). The following radio button options are available in this subsection:- Use simulation time – Selecting this radio button option allows the software to use the simulation date and time as the starting time.
- Fixed start time – Selecting this radio button option allows the user to enter a specific date and time to define the simulation period as the starting time.
- Date time interval
This dropdown combo box is used to select the time interval that defines the time series data. The following options are available:
Seconds Minutes Hours Days Weeks Months Years 1 second 1 minute 1 hour 1 day 1 week 1 month 1 year 2 seconds 2 minutes 2 hours 3 seconds 3 minutes 3 hours 4 seconds 4 minutes 4 hours 5 seconds 5 minutes 6 hours 6 seconds 6 minutes 8 hours 10 seconds 10 minutes 12 hours 12 seconds 12 minutes 15 seconds 15 minutes 20 seconds 20 minutes 30 seconds 30 minutes - Units
This dropdown combo box is used to define the unit for the time series data. The following options are available:- Inches
- In/hr
- Time Series Table
The Date & Time and Simulation Time data grid columns automatically get filled in based on the option selected in the Precipitation data starting date time subsection. The user can manually enter data values into the Precipitation data grid column fields.
Rainfall Time Series Plot
This section displays the Precipitation (in) vs Date time plot of the selected rain gage data. If no time series data is available, the graph will not show any data.