Diagnosis of wind flow and dispersion over complex terrain based on limited meteorological data

An estimation of SO2 dispersion over complex terrain is attempted, using the diagnostic wind field generated from limited meteorological data. This effort aims to face the realistic requirement of emergency-response in case of industrial plants settled in poorly instrumented areas. The combination of three numerical procedures is utilized: (1) detailed topographical simulation; (2) meteorological diagnosis using experimental data and accounting for terrain influences; and (3) dispersion calculations based on the diagnosed conditions. For the meteorological diagnosis a conditional exploitation of the measurements is made, allowing the inclusion of topographical effects. This is achieved by recognizing different terrain features, such as plains, valleys, slopes and coasts. This allows the division of the terrain into areas expected to follow the same with—or different from—the station, flow regime. Application is made for a power plant at Megalopolis valley, Greece. The hourly meteorological measurements from one surface station are used, with synoptic information from weather charts. The SO2 dispersion from three buoyant sources is calculated for several days. The obtained daily average concentrations at nine locations are compared with observational values, using the bootstrap resampling evaluation method.