The challenge of forecasting high streamflows 1–3 months in advance with lagged climate indices in southeast Australia

Skilful forecasts of high streamflows a month or more in advance are likely to be of considerable benefit to emergency services and the broader community. This is particularly true for mesoscale catchments (< 2000 km<sup>2</sup>) with little or no seasonal snowmelt, where real-time wa...

Full description

Bibliographic Details
Main Authors: J. C. Bennett, Q. J. Wang, P. Pokhrel, D. E. Robertson
Format: Article
Language:English
Published: Copernicus Publications 2014-02-01
Series:Natural Hazards and Earth System Sciences
Online Access:http://www.nat-hazards-earth-syst-sci.net/14/219/2014/nhess-14-219-2014.pdf
_version_ 1818365504059867136
author J. C. Bennett
Q. J. Wang
P. Pokhrel
D. E. Robertson
author_facet J. C. Bennett
Q. J. Wang
P. Pokhrel
D. E. Robertson
author_sort J. C. Bennett
collection DOAJ
description Skilful forecasts of high streamflows a month or more in advance are likely to be of considerable benefit to emergency services and the broader community. This is particularly true for mesoscale catchments (< 2000 km<sup>2</sup>) with little or no seasonal snowmelt, where real-time warning systems are only able to give short notice of impending floods. In this study, we generate forecasts of high streamflows for the coming 1-month and coming 3-month periods using large-scale ocean–atmosphere climate indices and catchment wetness as predictors. Forecasts are generated with a combination of Bayesian joint probability modelling and Bayesian model averaging. High streamflows are defined as maximum single-day streamflows and maximum 5-day streamflows that occur during each 1-month or 3-month forecast period. Skill is clearly evident in the 1-month forecasts of high streamflows. Surprisingly, in several catchments positive skill is also evident in forecasts of large threshold events (exceedance probabilities of 25%) over the next month. Little skill is evident in forecasts of high streamflows for the 3-month period. We show that including lagged climate indices as predictors adds little skill to the forecasts, and thus catchment wetness is by far the most important predictor. Accordingly, we recommend that forecasts may be improved by using accurate estimates of catchment wetness.
first_indexed 2024-12-13T22:21:19Z
format Article
id doaj.art-313b058a243f44f387c06139aacef369
institution Directory Open Access Journal
issn 1561-8633
1684-9981
language English
last_indexed 2024-12-13T22:21:19Z
publishDate 2014-02-01
publisher Copernicus Publications
record_format Article
series Natural Hazards and Earth System Sciences
spelling doaj.art-313b058a243f44f387c06139aacef3692022-12-21T23:29:22ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812014-02-0114221923310.5194/nhess-14-219-2014The challenge of forecasting high streamflows 1&ndash;3 months in advance with lagged climate indices in southeast AustraliaJ. C. Bennett0Q. J. Wang1P. Pokhrel2D. E. Robertson3CSIRO Land and Water, Graham Road, Highett, Victoria 3190, AustraliaCSIRO Land and Water, Graham Road, Highett, Victoria 3190, AustraliaCSIRO Land and Water, Graham Road, Highett, Victoria 3190, AustraliaCSIRO Land and Water, Graham Road, Highett, Victoria 3190, AustraliaSkilful forecasts of high streamflows a month or more in advance are likely to be of considerable benefit to emergency services and the broader community. This is particularly true for mesoscale catchments (< 2000 km<sup>2</sup>) with little or no seasonal snowmelt, where real-time warning systems are only able to give short notice of impending floods. In this study, we generate forecasts of high streamflows for the coming 1-month and coming 3-month periods using large-scale ocean–atmosphere climate indices and catchment wetness as predictors. Forecasts are generated with a combination of Bayesian joint probability modelling and Bayesian model averaging. High streamflows are defined as maximum single-day streamflows and maximum 5-day streamflows that occur during each 1-month or 3-month forecast period. Skill is clearly evident in the 1-month forecasts of high streamflows. Surprisingly, in several catchments positive skill is also evident in forecasts of large threshold events (exceedance probabilities of 25%) over the next month. Little skill is evident in forecasts of high streamflows for the 3-month period. We show that including lagged climate indices as predictors adds little skill to the forecasts, and thus catchment wetness is by far the most important predictor. Accordingly, we recommend that forecasts may be improved by using accurate estimates of catchment wetness.http://www.nat-hazards-earth-syst-sci.net/14/219/2014/nhess-14-219-2014.pdf
spellingShingle J. C. Bennett
Q. J. Wang
P. Pokhrel
D. E. Robertson
The challenge of forecasting high streamflows 1&ndash;3 months in advance with lagged climate indices in southeast Australia
Natural Hazards and Earth System Sciences
title The challenge of forecasting high streamflows 1&ndash;3 months in advance with lagged climate indices in southeast Australia
title_full The challenge of forecasting high streamflows 1&ndash;3 months in advance with lagged climate indices in southeast Australia
title_fullStr The challenge of forecasting high streamflows 1&ndash;3 months in advance with lagged climate indices in southeast Australia
title_full_unstemmed The challenge of forecasting high streamflows 1&ndash;3 months in advance with lagged climate indices in southeast Australia
title_short The challenge of forecasting high streamflows 1&ndash;3 months in advance with lagged climate indices in southeast Australia
title_sort challenge of forecasting high streamflows 1 ndash 3 months in advance with lagged climate indices in southeast australia
url http://www.nat-hazards-earth-syst-sci.net/14/219/2014/nhess-14-219-2014.pdf
work_keys_str_mv AT jcbennett thechallengeofforecastinghighstreamflows1ndash3monthsinadvancewithlaggedclimateindicesinsoutheastaustralia
AT qjwang thechallengeofforecastinghighstreamflows1ndash3monthsinadvancewithlaggedclimateindicesinsoutheastaustralia
AT ppokhrel thechallengeofforecastinghighstreamflows1ndash3monthsinadvancewithlaggedclimateindicesinsoutheastaustralia
AT derobertson thechallengeofforecastinghighstreamflows1ndash3monthsinadvancewithlaggedclimateindicesinsoutheastaustralia
AT jcbennett challengeofforecastinghighstreamflows1ndash3monthsinadvancewithlaggedclimateindicesinsoutheastaustralia
AT qjwang challengeofforecastinghighstreamflows1ndash3monthsinadvancewithlaggedclimateindicesinsoutheastaustralia
AT ppokhrel challengeofforecastinghighstreamflows1ndash3monthsinadvancewithlaggedclimateindicesinsoutheastaustralia
AT derobertson challengeofforecastinghighstreamflows1ndash3monthsinadvancewithlaggedclimateindicesinsoutheastaustralia