Open AccessDeveloping impact-based thresholds for coastal inundation from tide gauge observations
Author(s) -
Ben S. Hague,
Bradley F. Murphy,
David A. Jones,
Andy Taylor
Publication year - 2019
Publication title -
journal of southern hemisphere earth systems science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 7
ISSN - 2206-5865
DOI - 10.1071/es19024
Subject(s) - tide gauge , coastal flood , sea level , flooding (psychology) , flood myth , environmental science , sea level rise , oceanography , impact assessment , geography , climatology , physical geography , climate change , geology , psychology , archaeology , psychotherapist , public administration , political science
This study presents the first assessment of the observed frequency of the impacts of high sea levels at locations along Australia’s northern coastline. We used a new methodology to systematically define impact-based thresholds for coastal tide gauges, utilising reports of coastal inundation from diverse sources. This method permitted a holistic consideration of impact-producing relative sea-level extremes without attributing physical causes. Impact-based thresholds may also provide a basis for the development of meaningful coastal flood warnings, forecasts and monitoring in the future. These services will become increasingly important as sea-level rise continues.The frequency of high sea-level events leading to coastal flooding increased at all 21 locations where impact-based thresholds were defined. Although we did not undertake a formal attribution, this increase was consistent with the well-documented rise in global sea levels. Notably, tide gauges from the south coast of Queensland showed that frequent coastal inundation was already occurring. At Brisbane and the Sunshine Coast, impact-based thresholds were being exceeded on average 21.6 and 24.3 h per year respectively. In the case of Brisbane, the number of hours of inundation annually has increased fourfold since 1977.