A review of methods and systems available for flash flood forecasting

[摘要] This report presents a review of flash flood forecasting methods and systems as an initial phase of a study aiming to develop a forecasting system that will be used by the Bureau of Meteorology, Australia, to provide a flash flood warning service. In the report, characteristics of flash floods and causal factors such as hydro-meteorological processes, and hydrologic and hydraulic processes are described. Intense rainfall is the most common causal factor for flash flood formation. Advances in rainfall forecasting techniques and usage of remotely sensed data for flash flood forecasting are presented. Advance techniques for merging different sources of information (e.g. ground data, radar and satellite observations, numerical weather prediction model outputs) for producing better rainfall estimates and long lead-time rainfall forecasts are discussed. A number of flash flood forecasting models and methods are briefly described. Authors recognize that Physically-based Distributed Hydrological Models (PDHM) are more appropriate than data driven models and conceptual hydrological models for flash flood forecasting. The ability of PDHMs considering spatial distribution of rainfall and catchment state variables (e.g. soil moisture), and the potential for application to poorly-gauged catchments are advantages. Real-time updating of hydrological model parameters in the flash flood forecasting system is recommended. The two potential methods for flash flood forecasting in Australia are recognized as the flash flood guidance (FFG) method (section 4.2) and the statistical-distributed modelling (SDM) method (section 4.1.5). Their characteristics and operational feasibility are discussed. Further a probabilistic forecast approach that better represents the uncertainty associated with forecasts is recommended. Some of the operational flood forecasting systems used in different countries are described. Their advantages and limitations are suggested. Finally, future research directions to improve the quality of flash flood forecasts are discussed.

[发布日期] 2008-01-01 [发布机构] CSIRO

[学科分类] 地球科学(综合)