Download page Task 7. Filter and Modify Several Data Sets.
Task 7. Filter and Modify Several Data Sets
After data has been imported into the study, one or more filters can be applied to create new, modified data sets. For instance, an imported time series of daily precipitation accumulations spanning 1920 through 2018 can be filtered using an absolute time window spanning 1955 through 2010. Also, an annual maximum series can be extracted from a time series of hourly flows using the Annual Maximum filter. Filters can be nested as well. For example, an annual maximum series can be extracted from a time series of daily average reservoir stage for the time period between 1955 and 2010 using a season spanning 01Apr – 30Nov. The resulting annual maximum series would be comprised of peak stages that occurred between 01Apr and 30Nov in each year between 1955 and 2010. Filters that are available for use include:
Dates
Time Window
Season
Min / Max Threshold
Duration
Peaks
Annual Maxima
Peaks Over Threshold (Partial Duration Series)
Starting Pool Stage / Elevation
The previously-imported daily precipitation accumulations at Hawley, PA will be filtered to an annual maximum series as well as a partial duration series.
Right click on the "Hawley Daily Precipitation" data set within the Study Explorer and selectFilter Data.
On theDates and Thresholdtab, take note of the available filters. However, do not select any of them for this example.
Move to thePeakstab.
Click theFilter to Annual Maximacheck box and enter01Octwithin theStart of Yearentry field to specify use of water year. The Filter editor should appear similar to Figure 1.
Click theSave Filtered Data Set Asbutton.
Within the Save as New Data Set window, enter a name of "HAWLEY 1 E PA US-PRECIP-INC-Filtered-AMS" and an F-part of "AMS". Leave the remaining options unchanged. This window should appear similar to Figure 2.
ClickOKto save the new data set.
Right click on the new data set within the Study Explorer, selectEdit Metadata, and edit a Short ID to help identify it as the annual maximum series (e.g. "Hawley_AMS"). Click OK to close the window.
Right click on the "Hawley Daily Precipitation" data set within the Study Explorer and selectFilter Data.
Move to thePeakstab and click theFilter Data by Peaks Over Threshold (Partial Duration)check box.
Enter aMinimum Thresholdof1and delete the contents of theDuration of time between peaksentry field. The Filter editor should appear similar to Figure 3.
Click theSave Filtered Data Set Asbutton.
Within the Save as New Data Set window, enter a name of "HAWLEY 1 E PA US-PRECIP-INC-Filtered-PDS", a Short ID to help identify it as the partial duration series (e.g. "Hawley_PDS"), and an F-part of "PDS". Leave the remaining options unchanged. This window should appear similar to Figure 4.
ClickOKto save the new data set.
Select the Hawley Daily Precipitation data set in addition to the newly created annual maximum series and partial duration series by holding theCtrlkey and left clicking on each data set. Once the three data sets have been selected, clickData|Plot. A new window will appear containing the two data sets, as shown in Figure 5.