Author(s): S. Westra; R. Mehrotra; A. Sharma; S. Srikanthan
Linked Author(s):
Keywords: Continuous rainfall simulation; Method of fragments; Disaggregation; Sub-daily rainfall
Abstract: Continuous simulation of extended rainfall sequences is becoming an increasingly important tool in rainfall-runoff modelling and design flood estimation. Recently, a nonparametric approach was developed in which continuous (sub-daily) rainfall fragments are conditioned to daily rainfall on the current day and the rainfall state (wet or dry) on adjacent days using a k-nearest neighbour conditional resampling algorithm. A limitation of this approach is that extended pluviograph records at the location of interest are required, limiting applicability to only a small number of locations across Australia where such records are available. In this paper we present a generalisation to the above approach in which sub-daily rainfall fragments can be drawn from a set of ‘nearby' stations, with distance defined by latitude, longitude, distance to coast and elevation. This method performs well in simulating both Intensity-Frequency-Duration characteristics and antecedent moisture, and thus provides a framework for simulating continuous rainfall sequences at any location in Australia, provided long daily sequences are available or can be generated.
Year: 2011