EGU2020-1679, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-1679
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Drought assessment in a changing climate with the joint deficit index

Hans Van de Vyver, Joris Van den Bergh, and Bert Van Schaeybroeck
Hans Van de Vyver et al.
  • Royal Meteorological Institute of Belgium, Meteorological and Climatological Research, Brussels, Belgium (hvijver@meteo.be)

The characterization of droughts is very dependent on the time scale that is involved. To obtain an overall drought assessment, the cumulative effects of water deficits over different times need to be examined together. For instance, the joint deficit index (JDI) is based on multivariate probabilities of precipitation over various time scales from 1- to 12-months, and was constructed from empirical copulas. We examine the Gaussian copula model for the JDI, and we model the covariance across the temporal scales with a two-parameter function that is commonly used in the specific context of spatial statistics or geostatistics. The validity of the covariance models is demonstrated with long-term precipitation series.

Next, we assess the impact of climate change on future droughts, based on the JDI. We select an ensemble of CORDEX regional climate model simulations, under the emission pathways RCP4.5 and RCP8.5. The CORDEX resolution used is 0.11 degree (EUR-11). In particular, distributional changes in the JDI are analysed for the Brussels-Capital Region. This area contains climatological and synoptic stations that are operated by the Royal Meteorological Institute of Belgium, with long-term series.

 

How to cite: Van de Vyver, H., Van den Bergh, J., and Van Schaeybroeck, B.: Drought assessment in a changing climate with the joint deficit index, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1679, https://doi.org/10.5194/egusphere-egu2020-1679, 2019

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