Discussion on Paper by J. Amorocho, “The Nonlinear Prediction Problem in the Study of the Runoff Cycle”

The author [Amorocho, 1967] reaches a conclusion of such importance to hydrologic research that it cannot be left unchallenged. His primary conclusion is 'It is. shown that a. strictly deterministic approach to he establishment. of input-output relationships in the hydrologic cycle cannot be expected to succeed .... ' The basis of this conclusion is not completely clear to the writers, but he appears to, base it on Heisenberg's uncertainty principle in physics. Without quarreling with Heisenberg's principle, it is worthy of note that many very precise deterministic models have been derived in physics despite the principle of uncertainty. A classic example is, of course, the laws of motion derived by Newton. In short, Heisenberg's principle may apply to subatomic particles, but it does. not necessarily apply to apples.