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PROBABLE MAXIMUM PRECIPITATION (PMP)
• PMP is used in the design of major hydraulic structures such as spillways in large dams
• There appears to be a physical upper limit to the amount of precipitation that can occur over a given area in a given time
• PMP – It is the greatest or the extreme rainfall for a given duration that is physically possible over a raingauge station or a basin. It is that rainfall over a basin which would produce a flood with no risk of being exceeded
• PMP can be statistically estimated as PMP=
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are the mean of the annual maximum rainfall series, a frequency factor (that depends on the statistical distribution of the series, number of years of record, and the return period) and the standard deviation of the series respectively. K~ 15
