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Initial assessment of a multi-model approach to spring flood forecasting in Sweden

Olsson, J. LU ; Uvo, C. B. LU ; Foster, K. LU and Yang, W. (2016) In Hydrology and Earth System Sciences Discussions 12(6). p.6077-6113
Abstract

Hydropower is a major energy source in Sweden and proper reservoir management prior to the spring flood onset is crucial for optimal production. This requires useful forecasts of the accumulated discharge in the spring flood period (i.e. the spring-flood volume, SFV). Today's SFV forecasts are generated using a model-based climatological ensemble approach, where time series of precipitation and temperature from historical years are used to force a calibrated and initialised set-up of the HBV model. In this study, a number of new approaches to spring flood forecasting, that reflect the latest developments with respect to analysis and modelling on seasonal time scales, are presented and evaluated. Three main approaches, represented by... (More)

Hydropower is a major energy source in Sweden and proper reservoir management prior to the spring flood onset is crucial for optimal production. This requires useful forecasts of the accumulated discharge in the spring flood period (i.e. the spring-flood volume, SFV). Today's SFV forecasts are generated using a model-based climatological ensemble approach, where time series of precipitation and temperature from historical years are used to force a calibrated and initialised set-up of the HBV model. In this study, a number of new approaches to spring flood forecasting, that reflect the latest developments with respect to analysis and modelling on seasonal time scales, are presented and evaluated. Three main approaches, represented by specific methods, are evaluated in SFV hindcasts for three main Swedish rivers over a 10-year period with lead times between 0 and 4 months. In the first approach, historically analogue years with respect to the climate in the period preceding the spring flood are identified and used to compose a reduced ensemble. In the second, seasonal meteorological ensemble forecasts are used to drive the HBV model over the spring flood period. In the third approach, statistical relationships between SFV and the large-sale atmospheric circulation are used to build forecast models. None of the new approaches consistently outperform the climatological ensemble approach, but for specific locations and lead times improvements of 20-30 % are found. When combining all forecasts in a weighted multi-model approach, a mean improvement over all locations and lead times of nearly 10 % was indicated. This demonstrates the potential of the approach and further development and optimisation into an operational system is ongoing.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Hydrology and Earth System Sciences Discussions
volume
12
issue
6
pages
37 pages
publisher
Copernicus GmbH
external identifiers
  • scopus:85042738603
ISSN
1812-2108
DOI
10.5194/hessd-12-6077-2015
language
English
LU publication?
yes
id
99133c2e-ca66-4f53-99cd-a393f0edb1cf
date added to LUP
2018-03-14 10:10:12
date last changed
2019-02-20 11:10:43
@article{99133c2e-ca66-4f53-99cd-a393f0edb1cf,
  abstract     = {<p>Hydropower is a major energy source in Sweden and proper reservoir management prior to the spring flood onset is crucial for optimal production. This requires useful forecasts of the accumulated discharge in the spring flood period (i.e. the spring-flood volume, SFV). Today's SFV forecasts are generated using a model-based climatological ensemble approach, where time series of precipitation and temperature from historical years are used to force a calibrated and initialised set-up of the HBV model. In this study, a number of new approaches to spring flood forecasting, that reflect the latest developments with respect to analysis and modelling on seasonal time scales, are presented and evaluated. Three main approaches, represented by specific methods, are evaluated in SFV hindcasts for three main Swedish rivers over a 10-year period with lead times between 0 and 4 months. In the first approach, historically analogue years with respect to the climate in the period preceding the spring flood are identified and used to compose a reduced ensemble. In the second, seasonal meteorological ensemble forecasts are used to drive the HBV model over the spring flood period. In the third approach, statistical relationships between SFV and the large-sale atmospheric circulation are used to build forecast models. None of the new approaches consistently outperform the climatological ensemble approach, but for specific locations and lead times improvements of 20-30 % are found. When combining all forecasts in a weighted multi-model approach, a mean improvement over all locations and lead times of nearly 10 % was indicated. This demonstrates the potential of the approach and further development and optimisation into an operational system is ongoing.</p>},
  author       = {Olsson, J. and Uvo, C. B. and Foster, K. and Yang, W.},
  issn         = {1812-2108},
  language     = {eng},
  month        = {02},
  number       = {6},
  pages        = {6077--6113},
  publisher    = {Copernicus GmbH},
  series       = {Hydrology and Earth System Sciences Discussions},
  title        = {Initial assessment of a multi-model approach to spring flood forecasting in Sweden},
  url          = {http://dx.doi.org/10.5194/hessd-12-6077-2015},
  volume       = {12},
  year         = {2016},
}