Extreme Design Rainfalls for Victoria - new CRC software
September 14, 2000
The crcforge-extract computer program has been produced to facilitate the extraction of rare to extreme rainfalls from the (at present, Victorian) database, and to present the information in forms needed for hydrologic design.
Extreme Design Rainfalls for Victoria
The CRC-FORGE method, for analysing long periods of daily rainfalls for a region, is the outcome of a research program aimed to increase the reliability (and reduce the conservatism) of estimates of rainfall in the rare to extreme range (ie. annual exceedence probabilities less than 1%). The method is essentially a regional one, which can 'extend' the record at a point in a homogeneous region using the data from surrounding sites.
A CRC-FORGE database has been, or is being, prepared for the States of Victoria, New South Wales, Queensland, Tasmania and South Australia. Victoria is completed, and the database contains design rainfall estimates for the basic rainfall durations of 24, 48, 72, 96 and 120 hours, and annual exceedance probabilities (AEPs) from 1 in 50 to 1 in 2000, at a grid point spacing of 1/40 degrees in latitude and longitude (corresponding to approximately 2.5 km).
The crcforge-extract computer program has been produced to facilitate the extraction of rare to extreme rainfalls from the (at present, Victorian) database, and to present the information in forms needed for hydrologic design.
The crcforge-extract program can extract and interpolate point design rainfall estimates between 24 and 120 hours duration, and extrapolate them to shorter durations (to 6 hours). For application, these point rainfall estimates can be derived for a number of representative locations in a catchment or as average quantile values for a catchment defined by a regular/irregular polygon boundary. The program also allows the conversion of the point rainfalls to areal design rainfall estimates, and the construction of complete design rainfall frequency curves given the PMP estimates.
Copies of the crcforge-extract computer program and CRC-FORGE database on CD-ROM are available from the Centre Office (see contacts below).
The availability of CRC-FORGE data for other states will be advised.
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