Benchmarking an operational hydrological model for providing seasonal forecasts in Sweden
<p>Probabilistic seasonal forecasts are important for many water-intensive activities requiring long-term planning. Among the different techniques used for seasonal forecasting, the ensemble streamflow prediction (ESP) approach has long been employed due to the singular dependence on past mete...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-03-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://hess.copernicus.org/articles/25/1189/2021/hess-25-1189-2021.pdf |
| Summary: | <p>Probabilistic seasonal forecasts are important for many
water-intensive activities requiring long-term planning. Among the different
techniques used for seasonal forecasting, the ensemble streamflow prediction
(ESP) approach has long been employed due to the singular dependence on past
meteorological records. The Swedish Meteorological and Hydrological
Institute is currently extending the use of long-range forecasts within its
operational warning service, which requires a thorough analysis of the
suitability and applicability of different methods with the national S-HYPE
hydrological model. To this end, we aim to evaluate the skill of ESP
forecasts over 39 493 catchments in Sweden, understand their spatio-temporal
patterns, and explore the main hydrological processes driving forecast
skill. We found that ESP forecasts are generally skilful for most of the
country up to 3 months into the future but that large spatio-temporal
variations exist. Forecasts are most skilful during the winter months in
northern Sweden, except for the highly regulated hydropower-producing
rivers. The relationships between forecast skill and 15 different
hydrological signatures show that forecasts are most skilful for
slow-reacting, baseflow-dominated catchments and least skilful for flashy
catchments. Finally, we show that forecast skill patterns can be spatially
clustered in seven unique regions with similar hydrological behaviour. Overall,
these results contribute to identifying in which areas and seasons and how long
into the future ESP hydrological forecasts provide an added value, not only
for the national forecasting and warning service, but also, most importantly, for guiding decision-making in critical services such as hydropower management and
risk reduction.</p> |
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| ISSN: | 1027-5606 1607-7938 |