iMOD User Manual version 5.2 (html)

12.9STO Storage coefficients

The storage coefficient (for confined conditions) or specific yield (for unconfined conditions) of each modellayer is defined by one IDF (or a constant value). The value depends on the lithology of the modellayer. The storage coefficient in confined aquifers varies between 1x10\({}^{-}\)\({}^{5}\) to 1x10\({}^{-}\)\({}^{3}\). The specific yield ranges between \(0.02\) for clay to \(0.25\) for gravel. The STO storage coefficient corresponds with the SF1 variable specified in the MODFLOW BCF package and the SS and SY variable specified in the MODFLOW LPF package.