Local measurements of structural characteristics such as intrinsic microstrain along the c axis of the lattice ( = (c/c and its mean square fluctuation (, oxygen deficiency x, cation composition, etc. were performed on epitaxial YBa2Cu3O7 films grown on various substrates (MgO, BaSrTiO3/MgO, SrTiO3, LaAlO3, ZrO2/Si, Al2O3). A number of film microstrips were fabricated and the normalized flicker noise intensity (Hooge parameter () and the resistivity ( at 300 K were measured at each characterized point. A theoretical model was developed that explains the observed first growth of ( with ( and the well-known high level of the normal-phase flicker noise in various high temperature superconducting compounds. Comparison of the experimental and simulated dependence of ( on (, frequency, and temperature permits one to determine numerically the theoretical parameters of the double-well potential with minima located at the chain (O1) and empty (O5) oxygen lattice positions of the CuO plane.