RADIUS SOFTWARE

by Walter Dragoni

It can be shown that the drawdown s(cj) at the radius of influence computed according to the Cooper - Jacob formula is always given by the following formula: s(cj) = 0.039 Q/T, where Q and T are respectively the pumped flow and the transmissivity of the aquifer. Thus it can happen that s(cj) has a value of about one meter rather than zero. From a practical point of view, the radius of influence can be defined according to a specified drawdown, for instance that can be detected with the usual devices used in the field. The RADIUS code computes this radius of influence. More detailed explanations on this topic can be found in the paper : Dragoni W. (1998): Some Consideration Regarding The Radius of Influence of a Pumping Well, Hydrogeology, 3, pp. 21-25.