interannual_variation(series, normalize=False)[source]#

Interannual variation after [martens_2013].

  • series (pandas.Series) – Pandas Series with DatetimeIndex and head values.

  • normalize (bool, optional) – normalize the time series to values between zero and one.

Return type



The average between the range in annually averaged 3 highest monthly groundwater heads and the range in annually averaged 3 lowest monthly groundwater heads.

Inter-yearly variation of high and low water table (y):

y = ((max_HW - min_HW) + (max_LW - min_LW)) / 2

Warning: In this formulating the water table is references to a certain datum and positive, not as depth below the surface!



Martens, K., van Camp, M., van Damme, D., & Walraevens, K. (2013). Groundwater dynamics converted to a groundwater classification as a tool for nature development programs in the dunes. Journal of Hydrology, 499, 236–246.