Repository Description

This repository contains scripts and resources for calculating Cumulative Water Deficit (CWD) and Maximum Cumulative Water Deficit (MCWD) using Google Earth Engine (GEE). The project focuses on the Brazilian territory, with data processed on a 0.25° spatial grid, aiming to evaluate precipitation and evapotranspiration dynamics in order better to characterize drought intensity, duration, and spatial distribution. By leveraging GEE’s cloud-computing capabilities, the workflow ensures efficient and scalable processing of long-term climate datasets.

Key features

• Calculation of CWD and MCWD tailored for Brazil on a 0.25° grid.

• Automated processing, integration, and visualization within GEE.

• Use of precipitation and evapotranspiration data from multiple sources to enhance drought monitoring.

Methodological background

The implementation of CWD and MCWD in this repository builds on methodologies proposed in leading scientific studies on Amazonian droughts and fire impacts, including:

• Aragão, L.E.O.C., Malhi, Y., Roman-Cuesta, R.M., Saatchi, S., Anderson, L.O., & Shimabukuro, Y.E. (2007). Spatial patterns and fire response of recent Amazonian droughts. Geophysical Research Letters. https://doi.org/10.1029/2006GL028946

• Aragão, L.E.O.C., Anderson, L.O., Fonseca, M.G., Rosan, T.M., Vedovato, L.B., Wagner, F.H., Silva, C.V.J., Silva Junior, C.H.L., et al. (2018). 21st Century drought-related fires counteract the decline of Amazon deforestation carbon emissions. Nature Communications, 9, 536. https://doi.org/10.1038/s41467-017-02771-y

Data sources

• Evapotranspiration: geeSEBAL-MODIS (2003–2024) – projects/et-brasil/assets/geesebal/myd11a2/sa/v0-02
  Comini, B., Ruhoff, A., Laipelt, L., Fleischmann, A., Huntington, J., Morton, C., Melton, F., Erickson, T., Roberti, D., Souza, V., Biudes, M., Machado, N., Santos, C., & Cosio, E. (2023). geeSEBAL-MODIS: Continental scale evapotranspiration based on the surface energy balance for South America. DOI: 10.13140/RG.2.2.17579.11041

• Precipitation: CHIRPS Daily (UCSB-CHG/CHIRPS/DAILY)
  Funk, C., Peterson, P., Landsfeld, M., Pedreros, D., Verdin, J., Shukla, S., Husak, G., Rowland, J., Harrison, L., Hoell, A., & Michaelsen, J. (2015). The Climate Hazards Infrared Precipitation with Stations (CHIRPS): A new environmental record for monitoring extremes. Scientific Data, 2, 150066. DOI: 10.1038/sdata.2015.66

Applications

This project provides a methodological framework for researchers and practitioners in climate science, hydrology, ecology, and environmental management in Brazil who aim to quantify drought conditions and support adaptation and mitigation strategies.

Citation

If you use this repository, please cite the following DOI: 10.5281/zenodo.14635469.