GGU-DRAWDOWN: Optimise well radii

It is also possible to optimise the well radius.

In analogy to well depth optimisation, you enter the range of variation for the program here via a minimum and a maximum well radius. The input following "Delta radius" is used to define the variation spacing. Below this, specify whether a minimum drawdown should not be exceeded at the most unfavourable point. Well radii that do not adhere to this condition when the check box is activated are rejected. Once optimisation is complete the result is displayed and the optimised well radius can be accepted for further use. The optimised system should then be reanalysed.