Using an integrated hydrological model to estimate the usefulness of meteorological drought indices in a changing climate
Droughts are serious natural hazards, especially in semi-arid regions. They are also difficult to characterize. Various summary metrics representing the dryness level, denoted drought indices, have been developed to quantify droughts. They typically lump meteorological variables and can thus dire...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2016-10-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://www.hydrol-earth-syst-sci.net/20/4159/2016/hess-20-4159-2016.pdf |
| _version_ | 1818108453448581120 |
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| author | D. von Gunten T. Wöhling T. Wöhling T. Wöhling C. P. Haslauer D. Merchán J. Causapé O. A. Cirpka |
| author_facet | D. von Gunten T. Wöhling T. Wöhling T. Wöhling C. P. Haslauer D. Merchán J. Causapé O. A. Cirpka |
| author_sort | D. von Gunten |
| collection | DOAJ |
| description | Droughts are serious natural hazards, especially in semi-arid regions. They
are also difficult to characterize. Various summary metrics representing the
dryness level, denoted drought indices, have been developed to quantify
droughts. They typically lump meteorological variables and can thus directly
be computed from the outputs of regional climate models in climate-change
assessments. While it is generally accepted that drought risks in semi-arid
climates will increase in the future, quantifying this increase using climate
model outputs is a complex process that depends on the choice and the
accuracy of the drought indices, among other factors. In this study, we
compare seven meteorological drought indices that are commonly used to
predict future droughts. Our goal is to assess the reliability of these
indices to predict hydrological impacts of droughts under changing climatic
conditions at the annual timescale. We simulate the hydrological responses of
a small catchment in northern Spain to droughts in present and future
climate, using an integrated hydrological model calibrated for different
irrigation scenarios. We compute the correlation of meteorological drought
indices with the simulated hydrological time series (discharge, groundwater
levels, and water deficit) and compare changes in the relationships between
hydrological variables and drought indices. While correlation coefficients
linked with a specific drought index are similar for all tested land uses and
climates, the relationship between drought indices and hydrological variables
often differs between present and future climate. Drought indices based
solely on precipitation often underestimate the hydrological impacts of
future droughts, while drought indices that additionally include potential
evapotranspiration sometimes overestimate the drought effects. In this study,
the drought indices with the smallest bias were the rainfall anomaly index,
the reconnaissance drought index, and the standardized precipitation
evapotranspiration index. However, the efficiency of these drought indices
depends on the hydrological variable of interest and the irrigation scenario.
We conclude that meteorological drought indices are able to identify years
with restricted water availability in present and future climate. However,
these indices are not capable of estimating the severity of hydrological
impacts of droughts in future climate. A well-calibrated hydrological model
is necessary in this respect. |
| first_indexed | 2024-12-11T02:15:36Z |
| format | Article |
| id | doaj.art-775f38c5258e4d5ab1b35f7669335503 |
| institution | Directory Open Access Journal |
| issn | 1027-5606 1607-7938 |
| language | English |
| last_indexed | 2024-12-11T02:15:36Z |
| publishDate | 2016-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Hydrology and Earth System Sciences |
| spelling | doaj.art-775f38c5258e4d5ab1b35f76693355032022-12-22T01:24:11ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382016-10-01204159417510.5194/hess-20-4159-2016Using an integrated hydrological model to estimate the usefulness of meteorological drought indices in a changing climateD. von Gunten0T. Wöhling1T. Wöhling2T. Wöhling3C. P. Haslauer4D. Merchán5J. Causapé6O. A. Cirpka7University of Tübingen, Center for Applied Geoscience, Hölderlinstr. 12, 72074 Tübingen, GermanyUniversity of Tübingen, Center for Applied Geoscience, Hölderlinstr. 12, 72074 Tübingen, GermanyTechnische Universität Dresden, Department of Hydrology, Bergstr. 66, 01069 Dresden, GermanyLincoln Agritech Ltd., Ruakura Research Centre, Hamilton, New ZealandUniversity of Tübingen, Center for Applied Geoscience, Hölderlinstr. 12, 72074 Tübingen, GermanyGeological Survey of Spain – IGME, C/ Manuel Lasala no. 44, 9B, Zaragoza, 50006, SpainGeological Survey of Spain – IGME, C/ Manuel Lasala no. 44, 9B, Zaragoza, 50006, SpainUniversity of Tübingen, Center for Applied Geoscience, Hölderlinstr. 12, 72074 Tübingen, GermanyDroughts are serious natural hazards, especially in semi-arid regions. They are also difficult to characterize. Various summary metrics representing the dryness level, denoted drought indices, have been developed to quantify droughts. They typically lump meteorological variables and can thus directly be computed from the outputs of regional climate models in climate-change assessments. While it is generally accepted that drought risks in semi-arid climates will increase in the future, quantifying this increase using climate model outputs is a complex process that depends on the choice and the accuracy of the drought indices, among other factors. In this study, we compare seven meteorological drought indices that are commonly used to predict future droughts. Our goal is to assess the reliability of these indices to predict hydrological impacts of droughts under changing climatic conditions at the annual timescale. We simulate the hydrological responses of a small catchment in northern Spain to droughts in present and future climate, using an integrated hydrological model calibrated for different irrigation scenarios. We compute the correlation of meteorological drought indices with the simulated hydrological time series (discharge, groundwater levels, and water deficit) and compare changes in the relationships between hydrological variables and drought indices. While correlation coefficients linked with a specific drought index are similar for all tested land uses and climates, the relationship between drought indices and hydrological variables often differs between present and future climate. Drought indices based solely on precipitation often underestimate the hydrological impacts of future droughts, while drought indices that additionally include potential evapotranspiration sometimes overestimate the drought effects. In this study, the drought indices with the smallest bias were the rainfall anomaly index, the reconnaissance drought index, and the standardized precipitation evapotranspiration index. However, the efficiency of these drought indices depends on the hydrological variable of interest and the irrigation scenario. We conclude that meteorological drought indices are able to identify years with restricted water availability in present and future climate. However, these indices are not capable of estimating the severity of hydrological impacts of droughts in future climate. A well-calibrated hydrological model is necessary in this respect.https://www.hydrol-earth-syst-sci.net/20/4159/2016/hess-20-4159-2016.pdf |
| spellingShingle | D. von Gunten T. Wöhling T. Wöhling T. Wöhling C. P. Haslauer D. Merchán J. Causapé O. A. Cirpka Using an integrated hydrological model to estimate the usefulness of meteorological drought indices in a changing climate Hydrology and Earth System Sciences |
| title | Using an integrated hydrological model to estimate the usefulness of
meteorological drought indices in a changing climate |
| title_full | Using an integrated hydrological model to estimate the usefulness of
meteorological drought indices in a changing climate |
| title_fullStr | Using an integrated hydrological model to estimate the usefulness of
meteorological drought indices in a changing climate |
| title_full_unstemmed | Using an integrated hydrological model to estimate the usefulness of
meteorological drought indices in a changing climate |
| title_short | Using an integrated hydrological model to estimate the usefulness of
meteorological drought indices in a changing climate |
| title_sort | using an integrated hydrological model to estimate the usefulness of meteorological drought indices in a changing climate |
| url | https://www.hydrol-earth-syst-sci.net/20/4159/2016/hess-20-4159-2016.pdf |
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