Adding Value to BOM flood predictions

(Without messing around with models): Babister, M., Opper, S., Cinque, P., Chadwick, M., Davies, B. (2005) Presented at the 45th Annual Conference of the NSW Floodplain Management Authorities, Narooma, 22-25 February 2005

The Bureau of Meteorology (BoM) currently provides both real-time and predicted flood height information at a limited number of gauge sites within the Hawkesbury-Nepean basin. The task of value adding, where these flood heights are interpreted and transformed into flood information across the catchment, is the responsibility of the State Emergency Service (SES).

Operational decisions concerning mobilisation, flood warning announcements and evacuation measures are triggered by flood height information at the gauge sites. Currently, flood levels at other locations within the floodplain (e.g. at road crossings or key infrastructure sites) are extrapolated from the gauged heights using simple "rule-of-thumb" relationships. Unfortunately, the quality of these estimates is limited by the small number of available gauges. In addition, the relationships ignore the unique behaviour of each particular flood and do not vary with the size of the event.

This paper discusses a project initiated by the SES to address the constraints identified above. The outcomes include the implementation of operational tools that allow SES staff to transform real-time BoM predictions into a detailed map of flood information across the catchment. The tools are accessible through a range of software commonly used by SES staff including Microsoft Excel. Although relatively simple in their application, the tools utilise the information produced by complex hydraulic models without requiring the end-user to actually run or understand the models themselves. The tools developed provide improved estimates of flood height information across the floodplain that better reflect the unique behaviour of the flood event.

Download the research paper to find out more.