RAINFALL ESTIMATION IN SOUTH-WEST TASMANIA USING SATELLITE IMAGES ANDPHYTOSOCIOLOGICAL CALIBRATION

NOAA AVHRR digital data are used to map precipitation in southwest Tas mania, Australia. The technique uses multiple linear regression analys es between precipitation and satellite data to obtain yearly and seaso nal averages over a three-year period. These maps are later transforme d into long term average maps by drawing on linear relations between 3 -year and long term averages for various precipitation stations in the study area. Rms model residuals (measured-model) range from 0.45 mm d ay(-1) for the summer regression to 1.20 mm day(-1) for the winter reg ression. A significant fraction of this error may be attributed to lim itations in the rain gauge measurements. The predicted precipitation i s further verified by reference to variation in the alpine floras of t he study area which have a known relationship with soil conditions tha t vary with precipitation. Single axis ordination scores for the flora s show strong relationships with predicted precipitation both on a sea sonal and annual basis, especially in subsets related to substrate and region.