Seasonal drought prediction for semiarid northeastern Brazil: verification of six hydro-meteorological forecast products
<p>A set of seasonal drought forecast models was assessed and verified for the Jaguaribe River in semiarid northeastern Brazil. Meteorological seasonal forecasts were provided by the operational forecasting system used at FUNCEME (Ceará's research foundation for meteorology) and by the...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2018-09-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://www.hydrol-earth-syst-sci.net/22/5041/2018/hess-22-5041-2018.pdf |
| _version_ | 1818152183870259200 |
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| author | J. M. Delgado S. Voss G. Bürger K. Vormoor A. Murawski J. M. Rodrigues Pereira E. Martins F. Vasconcelos Júnior T. Francke |
| author_facet | J. M. Delgado S. Voss G. Bürger K. Vormoor A. Murawski J. M. Rodrigues Pereira E. Martins F. Vasconcelos Júnior T. Francke |
| author_sort | J. M. Delgado |
| collection | DOAJ |
| description | <p>A set of seasonal drought forecast models was assessed and verified for the
Jaguaribe River in semiarid northeastern Brazil. Meteorological seasonal
forecasts were provided by the operational forecasting system used at FUNCEME
(Ceará's research foundation for meteorology) and by the European Centre
for Medium-Range Weather Forecasts (ECMWF). Three downscaling approaches
(empirical quantile mapping, extended downscaling and weather pattern
classification) were tested and combined with the models in hindcast mode for
the period 1981 to 2014. The forecast issue time was January and the forecast
period was January to June. Hydrological drought indices were obtained by
fitting a multivariate linear regression to observations. In short, it was
possible to obtain forecasts for (a) monthly precipitation,
(b) meteorological drought indices, and (c) hydrological drought indices.</p><p>The skill of the forecasting systems was evaluated with regard to root mean
square error (RMSE), the Brier skill score (BSS) and the relative operating
characteristic skill score (ROCSS). The tested forecasting products showed
similar performance in the analyzed metrics. Forecasts of monthly
precipitation had little or no skill considering RMSE and mostly no skill
with BSS. A similar picture was seen when forecasting meteorological drought
indices: low skill regarding RMSE and BSS and significant skill when
discriminating hit rate and false alarm rate given by the ROCSS (forecasting
drought events of, e.g., SPEI<sub>1</sub> showed a ROCSS of around 0.5). Regarding
the temporal variation of the forecast skill of the meteorological indices,
it was greatest for April, when compared to the remaining months of the rainy
season, while the skill of reservoir volume forecasts decreased with lead
time.</p><p>This work showed that a multi-model ensemble can forecast drought events of
timescales relevant to water managers in northeastern Brazil with skill. But
no or little skill could be found in the forecasts of monthly precipitation
or drought indices of lower scales, like SPI<sub>1</sub>. Both this work and those
here revisited showed that major steps forward are needed in forecasting the
rainy season in northeastern Brazil.</p> |
| first_indexed | 2024-12-11T13:50:41Z |
| format | Article |
| id | doaj.art-19d1d734209541b29ad8649b8c2715f3 |
| institution | Directory Open Access Journal |
| issn | 1027-5606 1607-7938 |
| language | English |
| last_indexed | 2024-12-11T13:50:41Z |
| publishDate | 2018-09-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Hydrology and Earth System Sciences |
| spelling | doaj.art-19d1d734209541b29ad8649b8c2715f32022-12-22T01:04:17ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382018-09-01225041505610.5194/hess-22-5041-2018Seasonal drought prediction for semiarid northeastern Brazil: verification of six hydro-meteorological forecast productsJ. M. Delgado0S. Voss1G. Bürger2K. Vormoor3A. Murawski4J. M. Rodrigues Pereira5E. Martins6F. Vasconcelos Júnior7T. Francke8Institute of Earth and Environmental Sciences, University of Potsdam, Potsdam, GermanyInstitute of Earth and Environmental Sciences, University of Potsdam, Potsdam, GermanyInstitute of Earth and Environmental Sciences, University of Potsdam, Potsdam, GermanyInstitute of Earth and Environmental Sciences, University of Potsdam, Potsdam, GermanyGerman Research Centre of Geosciences GFZ Potsdam, Potsdam, GermanyResearch Institute for Meteorology and Water Resources – FUNCEME, Fortaleza, BrazilResearch Institute for Meteorology and Water Resources – FUNCEME, Fortaleza, BrazilResearch Institute for Meteorology and Water Resources – FUNCEME, Fortaleza, BrazilInstitute of Earth and Environmental Sciences, University of Potsdam, Potsdam, Germany<p>A set of seasonal drought forecast models was assessed and verified for the Jaguaribe River in semiarid northeastern Brazil. Meteorological seasonal forecasts were provided by the operational forecasting system used at FUNCEME (Ceará's research foundation for meteorology) and by the European Centre for Medium-Range Weather Forecasts (ECMWF). Three downscaling approaches (empirical quantile mapping, extended downscaling and weather pattern classification) were tested and combined with the models in hindcast mode for the period 1981 to 2014. The forecast issue time was January and the forecast period was January to June. Hydrological drought indices were obtained by fitting a multivariate linear regression to observations. In short, it was possible to obtain forecasts for (a) monthly precipitation, (b) meteorological drought indices, and (c) hydrological drought indices.</p><p>The skill of the forecasting systems was evaluated with regard to root mean square error (RMSE), the Brier skill score (BSS) and the relative operating characteristic skill score (ROCSS). The tested forecasting products showed similar performance in the analyzed metrics. Forecasts of monthly precipitation had little or no skill considering RMSE and mostly no skill with BSS. A similar picture was seen when forecasting meteorological drought indices: low skill regarding RMSE and BSS and significant skill when discriminating hit rate and false alarm rate given by the ROCSS (forecasting drought events of, e.g., SPEI<sub>1</sub> showed a ROCSS of around 0.5). Regarding the temporal variation of the forecast skill of the meteorological indices, it was greatest for April, when compared to the remaining months of the rainy season, while the skill of reservoir volume forecasts decreased with lead time.</p><p>This work showed that a multi-model ensemble can forecast drought events of timescales relevant to water managers in northeastern Brazil with skill. But no or little skill could be found in the forecasts of monthly precipitation or drought indices of lower scales, like SPI<sub>1</sub>. Both this work and those here revisited showed that major steps forward are needed in forecasting the rainy season in northeastern Brazil.</p>https://www.hydrol-earth-syst-sci.net/22/5041/2018/hess-22-5041-2018.pdf |
| spellingShingle | J. M. Delgado S. Voss G. Bürger K. Vormoor A. Murawski J. M. Rodrigues Pereira E. Martins F. Vasconcelos Júnior T. Francke Seasonal drought prediction for semiarid northeastern Brazil: verification of six hydro-meteorological forecast products Hydrology and Earth System Sciences |
| title | Seasonal drought prediction for semiarid northeastern Brazil: verification of six hydro-meteorological forecast products |
| title_full | Seasonal drought prediction for semiarid northeastern Brazil: verification of six hydro-meteorological forecast products |
| title_fullStr | Seasonal drought prediction for semiarid northeastern Brazil: verification of six hydro-meteorological forecast products |
| title_full_unstemmed | Seasonal drought prediction for semiarid northeastern Brazil: verification of six hydro-meteorological forecast products |
| title_short | Seasonal drought prediction for semiarid northeastern Brazil: verification of six hydro-meteorological forecast products |
| title_sort | seasonal drought prediction for semiarid northeastern brazil verification of six hydro meteorological forecast products |
| url | https://www.hydrol-earth-syst-sci.net/22/5041/2018/hess-22-5041-2018.pdf |
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