Assessing the benefit of snow data assimilation for runoff modeling in Alpine catchments
In Alpine catchments, snowmelt is often a major contribution to runoff. Therefore, modeling snow processes is important when concerned with flood or drought forecasting, reservoir operation and inland waterway management. In this study, we address the question of how sensitive hydrological models ar...
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doaj-6dda2ca1dc144262bb3cbd17352b40c42020-11-24T22:41:32ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382016-09-012093895390510.5194/hess-20-3895-2016Assessing the benefit of snow data assimilation for runoff modeling in Alpine catchmentsN. Griessinger0J. Seibert1J. Magnusson2T. Jonas3WSL Institute for Snow and Avalanche Research SLF, Davos, SwitzerlandDepartment of Geography, University of Zurich, Zurich, SwitzerlandNorwegian Water Resources and Energy Directorate (NVE), Oslo, NorwayWSL Institute for Snow and Avalanche Research SLF, Davos, SwitzerlandIn Alpine catchments, snowmelt is often a major contribution to runoff. Therefore, modeling snow processes is important when concerned with flood or drought forecasting, reservoir operation and inland waterway management. In this study, we address the question of how sensitive hydrological models are to the representation of snow cover dynamics and whether the performance of a hydrological model can be enhanced by integrating data from a dedicated external snow monitoring system. As a framework for our tests we have used the hydrological model HBV (Hydrologiska Byråns Vattenbalansavdelning) in the version HBV-light, which has been applied in many hydrological studies and is also in use for operational purposes. While HBV originally follows a temperature-index approach with time-invariant calibrated degree-day factors to represent snowmelt, in this study the HBV model was modified to use snowmelt time series from an external and spatially distributed snow model as model input. The external snow model integrates three-dimensional sequential assimilation of snow monitoring data with a snowmelt model, which is also based on the temperature-index approach but uses a time-variant degree-day factor. The following three variations of this external snow model were applied: (a) the full model with assimilation of observational snow data from a dense monitoring network, (b) the same snow model but with data assimilation switched off and (c) a downgraded version of the same snow model representing snowmelt with a time-invariant degree-day factor. Model runs were conducted for 20 catchments at different elevations within Switzerland for 15 years. Our results show that at low and mid-elevations the performance of the runoff simulations did not vary considerably with the snow model version chosen. At higher elevations, however, best performance in terms of simulated runoff was obtained when using the snowmelt time series from the snow model, which utilized data assimilation. This was especially true for snow-rich years. These findings suggest that with increasing elevation and the correspondingly increased contribution of snowmelt to runoff, the accurate estimation of snow water equivalent (SWE) and snowmelt rates has gained importance.http://www.hydrol-earth-syst-sci.net/20/3895/2016/hess-20-3895-2016.pdf |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
N. Griessinger J. Seibert J. Magnusson T. Jonas |
spellingShingle |
N. Griessinger J. Seibert J. Magnusson T. Jonas Assessing the benefit of snow data assimilation for runoff modeling in Alpine catchments Hydrology and Earth System Sciences |
author_facet |
N. Griessinger J. Seibert J. Magnusson T. Jonas |
author_sort |
N. Griessinger |
title |
Assessing the benefit of snow data assimilation for runoff modeling in Alpine catchments |
title_short |
Assessing the benefit of snow data assimilation for runoff modeling in Alpine catchments |
title_full |
Assessing the benefit of snow data assimilation for runoff modeling in Alpine catchments |
title_fullStr |
Assessing the benefit of snow data assimilation for runoff modeling in Alpine catchments |
title_full_unstemmed |
Assessing the benefit of snow data assimilation for runoff modeling in Alpine catchments |
title_sort |
assessing the benefit of snow data assimilation for runoff modeling in alpine catchments |
publisher |
Copernicus Publications |
series |
Hydrology and Earth System Sciences |
issn |
1027-5606 1607-7938 |
publishDate |
2016-09-01 |
description |
In Alpine catchments, snowmelt is often a major contribution to runoff.
Therefore, modeling snow processes is important when concerned with flood or
drought forecasting, reservoir operation and inland waterway management. In
this study, we address the question of how sensitive hydrological models are
to the representation of snow cover dynamics and whether the performance of a
hydrological model can be enhanced by integrating data from a dedicated
external snow monitoring system. As a framework for our tests we have used the
hydrological model HBV (Hydrologiska Byråns Vattenbalansavdelning) in the version HBV-light, which has been applied in
many hydrological studies and is also in use for operational purposes. While
HBV originally follows a temperature-index approach with time-invariant
calibrated degree-day factors to represent snowmelt, in this study the HBV
model was modified to use snowmelt time series from an external and spatially
distributed snow model as model input. The external snow model integrates
three-dimensional sequential assimilation of snow monitoring data with a
snowmelt model, which is also based on the temperature-index approach but
uses a time-variant degree-day factor. The following three variations of this
external snow model were applied: (a) the full model with assimilation of
observational snow data from a dense monitoring network, (b) the same snow
model but with data assimilation switched off and (c) a downgraded version of
the same snow model representing snowmelt with a time-invariant degree-day
factor. Model runs were conducted for 20 catchments at different elevations
within Switzerland for 15 years. Our results show that at low and mid-elevations the performance of the runoff simulations did not vary
considerably with the snow model version chosen. At higher elevations,
however, best performance in terms of simulated runoff was obtained when
using the snowmelt time series from the snow model, which utilized data
assimilation. This was especially true for snow-rich years. These findings
suggest that with increasing elevation and the correspondingly increased
contribution of snowmelt to runoff, the accurate estimation of snow water equivalent (SWE) and snowmelt rates has gained importance. |
url |
http://www.hydrol-earth-syst-sci.net/20/3895/2016/hess-20-3895-2016.pdf |
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AT ngriessinger assessingthebenefitofsnowdataassimilationforrunoffmodelinginalpinecatchments AT jseibert assessingthebenefitofsnowdataassimilationforrunoffmodelinginalpinecatchments AT jmagnusson assessingthebenefitofsnowdataassimilationforrunoffmodelinginalpinecatchments AT tjonas assessingthebenefitofsnowdataassimilationforrunoffmodelinginalpinecatchments |
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