Unleashing the Power of Copernicus: Enhancing Decision-Making with the European and Global Drought Observatories

Introduction: Copernicus and the Urgency of Drought Management

In 2022, Europe experienced one of the most severe droughts – as a result of precipitation deficits – in the past 500 years. This event is not isolated but part of a global trend where prolonged and severe droughts are becoming more frequent and intense. The consequences of drought are significant, affecting agriculture, water resources, energy production, and ecosystems worldwide.

Copernicus has revolutionised Earth Observation and environmental monitoring in recent years. Through cutting-edge satellite technology and advanced data analytics, Copernicus provides valuable information on natural hazards, including drought. This enables effective monitoring and empowers decision-makers to make informed choices.

The Copernicus Emergency Management Service (CEMS) is at the forefront of tackling drought-related challenges. As one of the six services provided by Copernicus, CEMS is dedicated to supporting early warning systems, oftentimes preparedness measures, emergency response efforts, and recovery activities. It plays a vital role in providing essential information to policymakers, emergency services, and the public during times of crisis. By utilising Earth Observation data, CEMS provides a valuable and unparalleled set of tools for effectively monitoring the impacts of drought.

Drought: Unveiling the Complex Phenomenon and Its Impacts

Drought is a weather condition characterised by persistent dry and/or hot conditions which disrupt the hydrological balance. It has short-term and long-term impacts on affected areas as well as areas downstream of the drought hit region and is exacerbated by prolonged and repeated heatwaves. The latter when occurring in winter leading to premature snowmelt. Droughts are typically categorised into three types: meteorological droughts, agricultural/ecological droughts, and hydrological droughts.

1. Meteorological droughts occur when there is a period of unusual precipitation deficit compared to the long-term average conditions for a region.

2. Agricultural/ecological droughts can follow meteorological droughts if they lead to soil moisture deficit and limited water availability for crops and grasslands. 

3. Hydrological droughts are characterised by reduced surface and sub-surface water availability, followed by a lowering of groundwater level and leading to saltwater intrusion in coastal areas.

Monitoring droughts involves monitoring various components of the hydrological cycle, such as precipitation, soil moisture, reservoir levels, river flow, and groundwater, as well as the impact of drought cycles on vegetation. CEMS drought observatories monitor most of these aspects.

Monitoring Drought: The Power of CEMS European and Global Drought Observatories

As flagship initiatives of the Copernicus Emergency Management Service, the Drought Observatories’ primary objective is to provide early warning and comprehensive information for drought events across Europe and the world. By integrating Earth Observation data from satellites, hydro-meteorological models, and in situ data, the European and Global Drought Observatories provide key drought indicators and serve as platforms supplying critical information for proactive drought management, response planning, and the development of resilient strategies. They equip decision-makers, stakeholders, the media, and the public with the tools to monitor and assess drought situations at various scales.

For instance, through the combination of spatial patterns of precipitation, soil moisture, and vegetation anomalies, EDO's leading product, the Combined Drought Indicator (CDI), provides unique insights into agricultural drought. CDI identifies areas at risk of drought, areas already experiencing vegetation stress, and areas in the recovery phase. With its classification scheme comprising three primary drought classes (Watch, Warning, and Alert) and three recovery classes (Temporary Soil Moisture Recovery, Temporary Vegetation Recovery, and Recovery), the CDI provides policymakers with a clear understanding of the drought situation.

European Drought Observatory (EDO) Combined Drought Indicator (CDI) for the first ten-day period of June 2023 [Credit: European Union, Copernicus EMS, EDO – 2023]

In addition to the Combined Drought Indicator (CDI), the European Drought Observatory (EDO) and Global Drought Observatory (GDO) provide other advanced products which detect statistical deviations from long-term averages. These products provide valuable insights into potential impacts on the economy and the environment. 

Global Drought Observatory (GDO) Standardised Precipitation Index (SPI) with four years accumulation period for South America [Credit: European Union, Copernicus EMS, GDO – 2023]

Other indicators, such as the “Low-Flow Index” (LFI)  a hydrological drought indicator - adopt threshold approaches to measure the volume of water deficit in rivers and reservoirs. These indicators assist in understanding the hydrological impacts of drought. The “Fraction of Absorbed Photosynthetically Active Radiation Anomaly” (FAPAR Anomaly) leverages satellite-derived data to quantify anomalies in vegetation health, indicating areas of relative stress.

CEMS Drought Observatories go beyond monitoring and provide indicators to forecast and provide early warning for drought events. One such indicator is the "Indicator for Forecasting Unusually Wet and Dry Conditions." It uses statistical analysis of predicted values of the aforementioned Standardised Precipitation Index (SPI) obtained from seasonal forecasting systems. This indicator identifies regions where unusually wet or dry periods are expected in the upcoming 1-, 3-, and 6-month periods. The intensity and coherence of the indicator align with the likelihood and duration of the forecasted conditions, delivering valuable insights for preparedness and planning purposes.

Insights from the Field: Drought Observatory Reports

In parallel with the monitoring and early warning activities, the Global Drought Observatory (GDO) provides regular updates on severe drought episodes through a series of “Joint Research Centre Technical Reports”. These serve as valuable resources for policymakers, researchers, and stakeholders involved in drought monitoring and management. By integrating various indicators and data sources, GDO/JRC provide detailed insights into the severity, spatial extent, temporal patterns, and economic impact of drought events. The latest examples of these report focused on: the western Mediterranean (May 2023), South America (April 2023), and Europe (March 2023).

Recent Advances: Enhancing Drought Monitoring and Management

The CEMS Drought Observatories have recently achieved significant milestones in their continuous efforts to further improve drought monitoring and management. One notable development is the launch of the new drought portal, which provides a user-friendly interface for accessing and exploring the wealth of drought-related information and resources provided by the observatories. 

This new and improved platform allows users to view the latest drought indicators, consult historical data, and use near real-time monitoring tools. The intuitive interactive map viewer enables them to freely explore, visualise, and download a vast array of drought data, as well as compare different drought indicators.

In addition, a new indicator has recently been released. It is called “Meteorological Drought Tracking”. It provides a spatial and temporal illustration of persistent dry conditions and has global coverage and an update frequency of ten days. It allows for a structured and clear analysis of specific drought episodes and is derived from the ERA5 fifth generation reanalysis.

European Drought Observatory (EDO) Meteorological Drought Tracking for the first ten-day period of May 2023 [Credit: European Union, Copernicus EMS, EDO – 2023]

Towards Resilience: Future Steps of CEMS Drought Observatories

Looking ahead, the CEMS Drought Observatories have embarked on an exciting initiative called the European Drought Observatory for Resilience and Adaptation (EDORA). This project is a cooperation between the European Commission’s Joint Research Centre (JRC) and DG Environment, and aims to strengthen the existing observatories by improving drought risk assessment at different scales, aggregating data on impacts in various sectors, and fostering connections among drought observatories across EU Member States. Providing a common core of operational data and knowledge about droughts, EDORA will enhance the resilience and adaptation to drought across the European Union.

The main outputs of the project will include a comprehensive drought impact database which collects and structures information on drought impacts over the past four decades across the EU. This database will facilitate a better understanding of the diverse impacts of drought in sectors such as agriculture, energy, public water supply, ecosystems, inland navigation, tourism, and human health. Additionally, the project will develop a drought risk assessment methodology and a drought risk atlas which will identify the current baseline of drought risks and future projections under different climate change scenarios. These outputs will significantly improve drought impact and risk assessment methods for various sectors.

In the near future the Observatories also aim at exploring the topic of seasonal-to-decadal forecasting, climate attribution for droughts, AI tools for droughts, and air and marine heatwaves. They will continue being present in important forums such as the task group of the Common Implementation Strategy of Water Directive Framework, the World Meteorological Organisation, the United Nations Convention to Combat Desertification, and others.

In the Media Spotlight: CEMS Drought Observatories' Impact

In the past years, the CEMS Drought Observatories attracted significant attention in the media thanks to their important contributions to drought monitoring and management. Media outlets have often highlighted the important role of EDO and GDO in monitoring and analysing drought events, disseminating near real-time drought indicators, and facilitating evidence-based decision-making. Some examples of data from Drought Observatories published in the media are provided below:

Figure 4. Examples of Drought Observatories data published on Euronews, Sky News, Cadena SER, El Debate.

Conclusion: Harnessing Copernicus Data for Drought Decision-Making

The Copernicus EMS Drought Observatories play a pivotal role within the Copernicus Emergency Management Service, providing a unique tool for monitoring, early warning, and management activities in relation to drought events. Through the integration satellite observations, hydro-meteorological models, and in situ data to provide key indicators, they empower decision-makers with timely and accurate information to understand, respond to, and mitigate the impacts of droughts. As drought continues to pose significant challenges, the European and Global Drought Observatories provide valuable data and resources which help in understanding, forecasting, and managing drought conditions.