  The dynamics of ecological as well as chemical systems may depend on
heterogeneous configurations. Heterogeneity in reaction-diffusion systems often
increase modelling and simulating difficulties when non-linear effects are
present. One synthetic epidemic system with short range heterogeneous
composition is modelled and its space-time evolution studied using maximum
heterogeneity details. Two other modelling alternatives are applied, one of
them using elementary mean-field variables, one other using non-localized
geometrical parameters, so avoiding the limitations of the used mean-field
model, while keeping significant features of more detailed models. Both the
detailed and the mean-field models are solved by means of the standard finite
volume method. The model with less defined geometry is solved by means of one
modified version of the finite volume method. Simulation results of the three
models are compared. At the high diffusion range all models behave similarly.
At moderate diffusion fluxes, the numerical results of the model with reduced
geometric details are in excellent agreement with the results of the detailed
model. The simple mean-field model presents limited accuracy at low and
moderate values of the diffusion coefficient.
