Minimum annual mean flow

Minimum annual mean flow calculated for n consecutive days. The VCN3 is used to characterize a situation of severe low water over a short period (3 days). The VCN30 gives information on the minimum resource over a month. Unlike low-flow (QMNA), it is calculated over a period of any 30 consecutive days. Using a sample of values of a parameter (e.g. VCN3), we calculate, for certain return periods, the statistic values of this parameter (e.g. biennial VCN3 or 2 years).