ABSTRACT
Borgesius generalized in 1912 the empirical work in groundwater flow as presented by Johan Pennink (1853-1936). He thereby used the mathematical analogy between groundwater flow and an electro-magnetic field. Borgesius simulated a number of analogous flow patterns based on such methods as superposition, imaging and refraction. However, Borgesius showed poor perception of the reality of groundwater hydrology by arguing that the streamline pattern around drainage galleries would make salinisation almost impossible. The noted physicist Hendrik Antoon Lorentz (1853-1928) demonstrated in a companion paper that a combination of the flow equation established by Henry Darcy (1803-1858) with the continuity equation results in the general differential equation that governs groundwater flow. This latter equation is an expression of the Laplace equation that also holds for electromagnetic fields and for heat conduction. Borgesius further presented a treatise on the lowering of a groundwater level around drains and up-coning of the fresh salt water interface, and added the comment that groundwater over-exploitation eventually leads to salinisation. In 1914, Pennink published his Salinisation Report, in which it is convincingly demonstrated that the boundary between fresh and salt water was slowly moving upwards and that several deep wells had indeed been affected by salinisation.
