Author(s): Shangyou Zhang; Gordon Mckay; Justin Robinson; Wei Wang
Linked Author(s):
Keywords: Real time flood forecasting; URBS model; Non-hydrological behaviors
Abstract: The New South Wales Flood Warning Centre (NSWFWC) within the Australian Bureau of Meteorology is responsible for the provision of flood forecasting and warning services for New South Wales (NSW). The Bureau itself is the statutory government body responsible for the provision of such services nationally. In order to improve the flood forecasting and warning services, the NSWFWC developed over 40 URBS models covering all major valleys of NSW. These URBS models are also set to become a key component of the Bureau’s next generation flood forecasting system – the HyFS. As a distributed and conceptual hydrological model, the URBS faces various challenges, including the non-hydrological behaviors (NHB) such as flow breakouts and floodplain attenuation which would normally require additional modeling tools to deal with. In many river valleys of NSW however, there is either a lack of data to replicate topographic conditions or a short lead time prohibiting lengthy simulations, making additional modeling tools impractical or cumbersome. For this reason, many URBS models developed by the NSWFWC incorporated simple solution schemes within the framework of the URBS model. In general, these models contributed to improved flood forecasting efficiency and accuracy, with a few exceptions where other issues, such as poor rainfall input caused inadequate model performance. This paper outlines the general characteristics of these URBS models, with particular emphasis on the solution schemes of the NHB, as well as highlighting the impact of poor rainfall to model performance, which are demonstrated in three case studies – the Gwydir Valley, the Namoi Valley, and the Cooks River. Notwithstanding the simplicity and the necessity for future improvements of the demonstrated solution schemes, results suggest that, for event based real time flood forecasting underpinned by reliable rainfall data, the hydrological modeling tools with embedded NHB solution schemes shall be a viable choice.
Year: 2013