This report describes the generalized theory and models which have been developed to establish an optimum meteorological and air pollution sampling network in urban areas. Three specific models are required in order to determine the optimum network: a three-dimensional hydrodynamic model; a statistical model; and an objective variational analysis model. The basis of the network is the wind field in the urban area rather than the air pollution distribution. The primitive hydrodynamic model is used to simulate the wind field over a variety of cases in which the major factors influencing the flow (urban heat island, surface roughness variability, topography, etc.) are included. Simulation data were then used to develop the form of a statistical model which could be used to describe the wind distribution over the domain of the network. The air pollution distribution is obtained through an objective variational analysis model. The models were applied to develop an optimum network for St. Louis, Missouri. In the summer of 1975 and winter of 1976, field programs were conducted to test and evaluate the optimum network. Results will be presented in a future report.