As a (maybe too) comprised answer: Darcy's law can be written in different ways (dependent on the hydrological 'problem' at hand). Yes, q in one direction (a specific discharge or volume flux density in m/day) =-K i . Q (a discharge or volume flux in m3/day) = -K i A, with A (in m2) being the total ground area perpendicular to the water flow. If you use Darcy's law in a vertical cross section for confined groundwater, the latter reduces to Q' (m2/day) = -K D i, with D being the saturated thickness or depth (in m) of the confined aquifer; if you use Darcy's law in a vertical cross section for unconfined groundwater, the latter reduces to Q' (m2/day) = -K h i, with h being the hydraulic head (in m) in the unconfined aquifer. Probably better is: If you want to come to full grips with groundwater flow in an unconfined aquifer (Dupuit-Forchheimer), I would recommend you to start off by (again?) studing the contents of lecture 3, part 1 of the playlist 'Physical Hydrology' on my RU-vid channel. After this, proceed by studying lecture 3, part 2; lecture 4; lecture 5; and lecture 6. This sequence builds up to the 'problem' of groundwater flow in an unconfined aquifer (in lecture 6; or in this stand-alone version). If you have any further questions (on the way), just let me know. I hope this is helpful or at least gets you started. Best wishes, Martin
