Many works are elaborated to derive interesting identities for hypergeometric-type series containing as a factor a digamma function. In the present paper, new reduction formulae for Kampé de Fériet series of types F2:1;0 1:2;1 and F3:1;0 2:2;1 are performed. By specializing certain parameters, series identities and related reduction identities are deduced. An interesting application is also studied concerning the evaluation of the average intensity of a multi-Gaussian beam propagating through a turbulent atmosphere.