# iMOD User Manual version 4.4 (html)

#### 12.7KVA Vertical anisotropy for aquifers

The vertical anisotropy (-) of each modellayer is defined by one IDF (or a constant value). The vertical anisotropy is multiplied with the horizontal permeability to calculate the vertical permeability in the permeable part of a modellayer (see Figure 12.3). The KVA vertical anisotropy corresponds with the VKA variable specified in the MODFLOW LPF package.