A revision of the Combined Drought Indicator (CDI) as part of the European Drought Observatory (EDO)

Abstract

Abstract. Building on almost ten years of expertise and operational application of the Combined Drought Indicator (CDI), which is operationally implemented within the European Commission’s European Drought Observatory (EDO) for the purposes of early warning and monitoring of agricultural droughts in Europe, this paper proposes a revised version of the index. The CDI conceptualizes drought as a cascade process, where a precipitation shortage (WATCH stage) develops into a soil water deficit (WARNING stage), which in turn leads to stress for vegetation (ALERT stage). The main goal of the revised CDI proposed here, is to improve the indicator’s performance for those events that are currently not reliably represented, without drastically altering the modelling framework. This is achieved by means of two main modifications: (a) use of the previously occurring CDI value to improve the temporal consistency of the timeseries, (b) introduction of two temporary classes – namely, soil moisture and vegetation greenness – to avoid brief discontinuities in a stage. The efficacy of the modifications is tested by comparing the performances of the revised and currently implemented versions of the indicator, for actual drought events in Europe during the last 20 years. The revised CDI reliably reproduces the evolution of major droughts, out-performing the current version of the indicator, especially for long-lasting events. Since the revised CDI does not need supplementary input datasets, it is suitable for operational implementation within the EDO drought monitoring system.

Potential of ecological modelling and smart-drainage development for mitigating adverse effects of future global change-type droughts for the Estonian forest sector

“…Data from the Copernicus European Drought Observatory (EDO) provides evidence that large parts of Estonia, as many other northern European countries, have (de Roo et al, 2000;Cammalleri et al, 2020). Subsequently, soil moisture values are transformed into standardized values by comparison to a long-term reference period (i.e.…”

EMO-5: A high-resolution multi-variable gridded meteorological data set for Europe

“…The evaluation of the resulting grid quality focuses on the gridded precipitation data, as these are the most crucial drivers for environmental or hydrological modelling. The data set is already being successfully applied not only by EFAS, but also by two other major services of Copernicus EMS, namely the European Forest Fire Information System (EFFIS; https://effis.jrc.ec.europa.eu/; San-Miguel, J. et al, 2019) and the European Drought Observatory (EDO; https://edo.jrc.ec.europa.eu/; Spinoni et al, 2016;Cammalleri, C. et al, 2020). By making the EMO-5 data publicly available, we aim to support many other environmental applications and services that would benefit from using those data.…”