Hello Yao;

Use <DSSTS>,a small stand-alone program, to enter manually your Regular Interval Time Series OR to convert an existing ASCII file into a DSSfile.

To convert an ASCII file to a DSS file, 5 lines are to be added to the top of the one- column (ASCII/text) file containing the time series and --- an END is to be placed at the very last line of the file:

1st Line: DSS Filename to be created.
2nd Line: Full Six-part Pathname (A=project name B=site/station
C=the data variable e.g., FLOW , STAGE ,etc.
D=01JAN1955 E= timestep,e.g., 2HOUR F= remarks OBSERVED
3rd Line: Unit of data ( CMS, Meters, mm , MCM, mamsl, etc.)
4th Line: Data Type [could be any of the PER-AVER (average for the
period) or PER-CUM or INST-VAL (instantaneous values) or INST-CUM].
5th Line: Date & Time for the first data value, e.g. 09OCT1995,0600

An END should be typed in after the last line of the data is entered.

In the INTERACTIVE mode the above listed items are asked by the program & the user just types them in.

You need separate (ASCII) files for your flow and stage time series. Here is an example from your Excel file for your first few FLOW data:
------------------------------------
YAO-1.dss
A=YOUR PROJECT B=SITE-8 C=FLOW D=01JAN2000 E=2HOUR F=JUST TESTING
CFS
PER-AVER
11FEB2000,1200
1106 <--- cut and paste your FLOW data here (starting @ 6th line)
1106
8
1106
1106
1106
1106
1106
1106
1106
... <-------- snipped
...
END
------------------------------
Now when finished creating the text file and naming it (e.g., YAO-1.txt) then enter the following command : DSSTS IN=YAO-1.txt , you'll get the DSS file (YAO-1.DSS) you need, as Jeremy explained, to import into your RAS model.

Good Luck!
Mostafa Bozorg-Zadeh
bozorg@KOSAR.NET