Drought and Drought Observation
Droughts are caused by a lack of precipitation over a prolonged period of time. Since the average amount of precipitation varies spatially, the definition of drought periods needs to take local characteristics into account.
Drought monitoring is based on the evaluation of various indices. The standardized precipitation index (SPI) shows the deviation from average precipitation and is therefore directly related to drought risk. Additional indices monitor the status of soil moisture, vegetation, groundwater levels, etc. to determine the impacts of droughts. The various indices are collected by different means, ranging from precipitation measurements of weather stations to remote sensing images for vegetation states. The JRC collects series of drought indices on a continental level. This drought monitoring data is complemented by additional drought indices, that are prepared by national, regional or local organizations.
Drought experts analyse the quantitative measures of drought impacts by comparing historic data with actual measurements. Based on this analysis they can make an informed statement regarding the current drought situation. The continuous observation of the drought conditions in Europe shall therefore facilitates the detection of the onset, duration and drought periods.
Additional statistical analyses of drought data lead forecasts of the drought situation. The forecasting aspects of the European Drought Observatory are the subject of ongoing research activities at the JRC.
This website provides the fundamental data and tools for an analysis of the current drought situation. The interpretation of the drought indices by experts of the Joint Research Centre of the European Commission is provided in the section "Drought Situation"
. The data on which these interpretations are based, is provided in the "Data & Tools"