Africa - Monthly and dekadal combined drought indicator (CDI)

Name: Africa - Monthly and dekadal combined drought indicator (CDI)
Creator: African Center of Meteorological Applications for Development
License: http://www.opendefinition.org/licenses/cc-by

✦ DISCOVERED BY ORIONAIAfrican Center of Meteorological Applications for DevelopmentClimate and weatherAfrica

Loading the data…Africa

About this dataset

The Combined Drought Indicator (CDI) dataset developed at ACMAD is designed as an operational drought-monitoring product that synthesizes multiple biophysical signals into a single, coherent assessment of drought conditions across Africa. Rather than relying on a single indicator, the ACMAD CDI combines information from rainfall-based drought indices and satellite-derived vegetation condition metrics, applying rule-based logic to identify areas where these independent indicators consistently point to drought stress. This convergence approach reduces the risk of false alarms that can arise from short-term rainfall variability or vegetation anomalies unrelated to drought. The data exist in two forms one based on GPCC while another based on Era5 precipitation. The dataset is particularly useful in the African context, where ground observations are sparse and climatic gradients are strong across regions. By using harmonized, gridded datasets, the CDI provides a comparable drought signal across national boundaries, supporting regional coordination and continental-scale analysis. Its categorical outputs are intentionally simple and policy-ready, making them suitable for drought bulletins, early-warning communications, and high-level decision support. Importantly, the CDI is not intended to replace detailed drought diagnostics or impact assessments. Instead, it serves as a convergence and confirmation tool that highlights areas requiring closer analysis and expert interpretation. In this role, the CDI acts as a bridge between complex climate data and practical drought-risk management, enabling timely, consistent, and defensible drought monitoring at regional and continental scales.

Documentation

The Combined Drought Indicator (CDI) is derived from the combination of SPI, SMA and fAPAR, to identify areas with the potential to suffer agricultural drought, areas where the vegetation is already affected by drought conditions, and areas in the recovery process to normal conditions after a drought episode. **Value Ranges:** * **1-3:** watch * **4-6:** warning * **7-10:** alert * **11-12:** partial-recovery * **13-14:** full-recovery Each ZIP download contains the original scanned TIFF files for a single calendar year, including monthly and dekadal scans. The files are provided in a ZIP archive to preserve the original sources and may be extracted and converted as needed. The data may require interpretation with its building blocks such as the vegetation, soil moisture or rainfall to fully place the cause of the drought, highly dependent on the data source, in this case SPI, soil moisture anomaly and vegetation anomaly which may vary depending with number of weather stations sharing data on a geographic location.

Related datasets

✦ Suggested by OrionAI

Africa - CDI based on ERA5 Precipitation

This version of the Combined Drought Indicator (CDI) utilizes ERA5 reanalysis data as the primary input for the precipitation component (SPI), rather than gauge-only or other satellite-blended products. ERA5, produced by ECMWF, offers comprehensive spatial coverage and temporal consistency, making it valuable for regions where gauge networks are failing or sparse. Like the standard CDI, this dataset synthesizes rainfall deficits (via ERA5), soil moisture anomalies, and vegetation stress into a single classification system to monitor the evolution of drought episodes.

Climate and weather · African Center of Meteorological Applications for Development

View Save

IGAD Region - Monthly Combined Drought Indicator (CDI) 2025

Monthly Combined Drought Indicator (CDI) as implemented in the East Africa Drought Watch, and which is used for detecting and monitoring areas that either are affected or have the potential to be affected by meteorological, agricultural and/or hydrological drought.

Climate and weather · IGAD Climate Prediction and Applications Center (ICPAC)

View Save