Published April 14, 2025 | Version v1
Dataset Restricted

DBSCAN 3D Clusters of SPEI-90 days – Linguere, Senegal, 1981-2023

Description

Science Case Name 

Multi-Hazards in Senegal.

Dataset Name/Title 

DBSCAN 3D Clusters of SPEI-90 days – Linguere, Senegal, 1981-2023

Dataset Description 

The dataset contains gridded data on SPEI-90 days over Linguere area of Senegal.

Key Methodologies 

Droughts were computed with SPEI-90, with daily precipitation from Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) (1981-2023) and daily maximum, average and minimum air temperature from ERA5-Land. Potential evapotranspiration (PET) was computed with the Hargreaves equation from the SPEI R package. Water balance, the difference between precipitation and PET, was aggregated to 90-day rolling sums and Z-scores were computed from distributions of values from day of year (43 points).  Days with Z-scores below or equal to –1 were marked as droughts.

Spatio-temporal DBSCAN was conducted with Python packages st_dbscan https://github.com/eren-ck/st_dbscan (Cakmak et al., 2021). Spatial proximity (epsilon 1) was set to 0.5 (0.5 degree), temporal proximity (epsilon 2) was set to 1.5 (1.5 days); min number of samples was set to 30.

The values in the NetCDF files represent cluster numbers (from 0 to 11), with values -1 (negative 1) representing outliers.

A summary table in CSV represents rows for each cluster with start and end dates, average severity and intensity, and maximum number of affected cells.

Temporal Domain 

1981–2023, daily

Spatial Domain 

Linguere, Senegal, West Africa

Spatial resolution ca 0.1°x0.1° (EPGS:4326)

Key Variables/Indicators 

Spatio-temporal clusters of dry/drought events

Data Format 

netCDF

CSV 

Source Data 

ERA5-Land daily min, max and average air temperature and CHIRPS daily precipitation

Accessibility 

Zenodo, https://doi.org/10.5281/zenodo.15212446

Stakeholder Relevance 

Identifying and assessing past drought events for multi-hazard events monitoring, prediction and preparedness.

Limitations/Assumptions 

The clustering was done over the specified region only.

Each calendar year was clustered independetly.

Additional Outputs/information

The dataset access is currently restricted due to pending related publication.

Contact Information 

Egor Prikaziuk (UT-ITC, Faculty of Geo-Information Science and Earth Observation, ITC, University of Twente, the Netherlands)

Files

Restricted

The record is publicly accessible, but files are restricted to users with access.

Additional details

Funding

European Space Research Institute
EO4Multihazards (Earth Observation for High-Impact Multi-Hazards Science), funded by the European Space Agency and launched as part of the joint ESA-European Commission Earth System Science Initiative

References

  • Cakmak, E., Plank, M., Calovi, D. S., Jordan, A., & Keim, D. (2021). Spatio-temporal clustering benchmark for collective animal behavior. Proceedings of the 1st ACM SIGSPATIAL International Workshop on Animal Movement Ecology and Human Mobility, 5–8. https://doi.org/10.1145/3486637.3489487