Be able to define the term 50 year flood . Don t worry too much about the specifics of how to do a flood frequency analysis. Read the box on p. 7-6 that explains the water year, and the sources of streamflow data. Daily mean streamflow is the average discharge at a specific gauging station for a specific 24-hour period. It is called the mean streamflow because the gauge actually measures discharge several times during each 24 hour period, and these values are averaged to produce the mean for the day.
Peak flows are flood flows.
The peak flow discharge is the instantaneous peak flow value, the highest discharge rate that occurred during the highest day of the flood. The annual flood for a given year is the largest instantaneous discharge rate that occurred at that gauging station during the year. Read about low-flow frequency analysis, but don t focus on the details of how to do it. Get a sense of what low-flow analysis is, and what it is used for. Look at Fig.