Table 4 Magnitude frequency relationships for SMD based on 11 years weighing lysimeter data at CHRS

Where y = modified reduced variate = [(-ln ln (1- 1/T) – 3.3842) * 1.09348 * T-0.046518] + 3.3842. Where T = return period (years).

End of
April SMD = -39.818y – 16.085
May SMD = -19.586y + 20.068
June SMD = -29.364y + 36.068
July SMD = -30.433y + 51.054
August SMD = -16.706y + 39.180
September SMD = -16.926y + 0.180