This code collection tackles the problem of satellite-based drought monitoring in Aotearoa New Zealand. The work is organised by programmatic environment/interface and then by project, with each project file containing its own readme, with differing levels of 'user friendliness'.
- Python:
- VERDANT: the original fast-VTCI work conducted at the National Centre for Earth Observation (UK).
- GoogleEarthEnginge:
- Taranaki_FastVTCI: regional drought analysis with ground validation from Taranaki Regional Council soil moisture stations.
- Code: This code is more user-friendly than the original VERDANT code and includes changes made to the filtering and database collation steps as described in the manuscript. There are three scripts that can be run directly on GEE using the code editor (01_DatabaseBuild, O2_CalculateVTCIGroundSites and 03_Fast-VTCI-Vis). A Juptyer Notebook is used to step through the intermediate steps (joins and edge calculation). The notebook is also used to conduct the validation exercises as described in the manuscript.
- Code Outputs: Sub directories of with the resulting outputs from each run of the fast-VTCI as described in the associated manuscript. "17_09_SAVI_T" is the tradtional VTCI run for the SAVI index. Each folder contains folders with LST and SAVI outputs generated from the 01_DatabaseBuildTaranaki and 01_DatabaseBuildTaranaki scripts, combined files used in the edge calculations, edges saved as .joblib files, resulting VTCI results from the 02_CalculateVTCI_GroundSites script, time series plots and validation results.
- Taranaki_FastVTCI: regional drought analysis with ground validation from Taranaki Regional Council soil moisture stations.
Authors: D Smith, TPF Dowling
Copyright 2026 TPF Dowling & D Smith
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