frequency


Updated on 13/07/2018
Définition
Sens technique
For a low-water flow lower or equal to a given value "a", the ratio between the number of observations made in a series of flows (usually monthly), where the flow remains below this value "a", and the total number of observations in this series (FEtiage = number of observations with Q ? a / total number of observations). For a flood flow rate greater than or equal to a given value "b", the frequency is the ratio between the number of observations made in a series of flows (usually monthly), where the flow exceeds this value "b", and the total number of observations in this series (FCrue = number of observations with Q ? b / total number of observations). These two limit values "a" and "b" are not identical. For the frequency to be reliable, the series must have at least 30 observations.
Source
According to the Ministry for the Environment and AFB
Thématiques associées
Termes associés à des définitions du Sandre
Review status
Soumis au comité de relecture.