Reproducible data and code accompanying the manuscript: Temporal drought characteristics in semi-arid Northern Tanzania based on multi-scale SPI and SPEI (1994–2024)
# Simanjiro drought analysis reproducibility package
This repository reproduces the SPI and SPEI analyses for Simanjiro District, Tanzania, for January 1994–December 2024.
## Contents
- `R/`: ordered R scripts for data preparation, PET, SPI/SPEI, classification, distribution diagnostics, TFPW trend analysis, FDR correction, post-whitening diagnostics, SPI–SPEI comparison, residual drought, PET sensitivity, and exploratory Pettitt tests.
- `data/`: location for the restricted TMA input workbook.
- `outputs/`: generated processed datasets, tables, and figures.
- `metadata/`: package versions, analysis settings, and complete R session information.
- `run_all.R`: runs the complete workflow.
## Input data
Place the TMA workbook in:
`data/SIMANJIRO_DATA.xlsx`
The workbook must contain a worksheet named `Monthly_Data` with:
- rainfall in `A2:M33`,
- monthly Tmax in `A35:M66`,
- monthly Tmin in `A68:M99`,
- the first column named `Year`,
- monthly columns named `Jan` to `Dec`.
The workflow checks that the series contains 372 continuous monthly observations and no missing rainfall or temperature values.
## Run
Open R in the repository root and run:
```r
source("run_all.R")
```
## Main methods
- SPI: Gamma distribution, unbiased probability-weighted moments.
- SPEI: log-logistic distribution, unbiased probability-weighted moments.
- Primary PET: Thornthwaite.
- PET sensitivity: Hargreaves–Samani using Tmin and Tmax.
- Accumulation periods: 3, 6, 9 and 12 months.
- Trend analysis: Trend-Free Pre-Whitening Mann–Kendall with Benjamini–Hochberg FDR correction.
- Drought threshold: index ≤ −1.00.
- Non-finite index values are retained in the audit and converted to missing only for downstream finite-value analyses.
## Data restrictions
---
# Citation
This repository is archived in Zenodo and can be cited using the following DOI:
doi.org
GitHub repository:
github.com
Raw meteoro …