Continuous Simulation System for Design Flood Estimation
July 20, 2000
A simulation package, which generates rainfalls to route through a catchment model to estimate design floods, is now downloadable from the CRC website.
In the 'design flood' approach in current use in flood estimation practice, median values of the flood producing components (eg rainfall temporal patterns, losses, baseflow) are adopted to convert a design rainfall to a design runoff having the same probability of occurrence.
The aim of CRC Project FL1 'Holistic Approach to Rainfall-Based Design Flood Estimation' was to account specifically for the distribution of, and interactions between, the most influential components of flood hydrograph generation. Two approaches were investigated:
(i) a joint probability approach, and
(ii) continuous simulation.
The model system presented is an output from (ii).
The Continuous Simulation System for Design Flood Estimation consists of
* a catchment water balance model for continuous simulation of losses which produces rainfall excess at hourly time intervals
* a flood hydrograph model for converting rainfall excess to hydrographs of hourly flow at the catchment outlet
* a data generation model for generating 2000 year sequences of daily rainfalls
* a model for disaggregating the larger generated daily rainfalls into hourly values
The models can be downloaded from the CRC for catchment Hydrology website.
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