Disaggregation of daily rainfall by conditional simulation from a point-process model

Abstract

Series of hourly rainfall data are simulated which are consistent with recorded daily totals. A two-stage process is used. First, a long sequence of hourly data is simulated using the Rodriguez-lturbe rainfall model (Rodriguez-Iturbe et al., Proc. R. Soc. London, Ser. A, 417, 283–298, 1988). Then, comparisons are made in daily totals between all observed and all simulated 3 day sequences. For each observed sequence, the simulated rainfall which gives the best match is re-expressed on an hourly basis, and used as one possible realisation of hourly rainfall on those days. For Edinburgh, Turnhouse, for which hourly data are available, the agreement between observed and disaggregated series is good, in terms of both histograms of hourly rainfall and summary statistics.