SPATIAL INTERPOLATION OF STOCHASTIC WEATHER MODEL PARAMETERS

A methodology for the spatial representation of the parameters of stoc hastic weather models is presented. This method provides an efficient method for the space-time modelling of weather data as inputs to other agricultural, ecological and hydrological models used in weather impa ct assessments. The seasonal variation of the parameters of a point ra infall model, the Rectangular Pulses Poisson model, is represented by a quadratic polynomial spline. The coefficients of this representation are then spatially interpolated as functions of position as well as p osition and elevation. Thin plate smoothing splines are used in the in terpolation procedure, and the methodology is tested with data from 10 2 stations in the Darling Downs region of South-East Queensland, Austr alia. Further testing with an independent data set demonstrates the ad equacy of the technique in preserving historical statistics from the c oefficients of the interpolated surfaces. A useful extension of this m ethodology to provide stochastic weather data for future climate scena rios is also discussed. (C) 1997 Academic Press Limited