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countyfloods (version 0.0.2)

construct_prob_plot: Construct probability plot using the Weibull plotting method

Description

Construct probability plot using the Weibull plotting method

Usage

construct_prob_plot(vals)

Arguments

vals
A numeric vector of annual peak discharge values obtained from the readNWISpeak function of the dataRetrieval package.

Details

The Weibull plotting method is commonly used in flood-frequency analysis. The basic procedure invovles ranking the values from highest to lowest and calculating an exceedence probability (\(p = rank / (n + 1)\)) where n is the total number of observations. The median annual flood (Q2) is the flow with a probability of 0.5.

References

Rao, A.R. and Hamed, K.H. 2000. Flood Frequency Analysis. CRC Press: Boca Raton.