---

name: forest-disturbance-alert description: Detect forest disturbance from multi-temporal NDVI. Use when the user wants to analyze changes, detect hazards, or generate assessment reports.

Forest Disturbance Alert

Detect forest disturbance from multi-temporal NDVI.

CLI Usage

python scripts/forest_disturbance_alert.py --baseline baseline.tif --current current.tif
python scripts/forest_disturbance_alert.py --baseline baseline.tif --current current.tif --threshold 0.25
python scripts/forest_disturbance_alert.py --baseline baseline.tif --current current.tif --output-dir my_output

Parameters

Argument	Required	Default	Description
--baseline	Yes	—	Path to baseline (undisturbed) NDVI raster
--current	Yes	—	Path to current NDVI raster (same grid as --baseline)
--threshold	No	0.2	NDVI drop threshold (current − baseline < −threshold is flagged)
--output-dir, -o	No	disturbance-output	Directory to write outputs

Output

File	Description
disturbance-report.json	Machine-readable disturbance stats (affected area, severity classes)
report.html	Human-readable HTML report
output-manifest.json	Run metadata + result summary

Exit Codes

Code	Meaning
0	Success
2	Argument error
7	Processing failure

数据下载

本 skill 可自动从 Microsoft Planetary Computer 下载数据 (无需 API key):

python forest_disturbance_alert.py --bbox 116,39,117,40 --date-range 2024-06-01,2024-06-30 --output-dir <tmp>

• --bbox W,S,E,N: WGS-84 边界框 (西, 南, 东, 北)
• --date-range START,END: 日期范围 (YYYY-MM-DD,YYYY-MM-DD)
• --aoi-file <path.geojson>: 替代 --bbox 的 GeoJSON 多边形
• --cache-dir <path>: 缓存目录 (默认 ~/.geoskill_cache)

当用户只给 --bbox + --date-range (没有 --baseline) 时，skill 自动下载数据。 当用户给 --baseline 时，走原文件路径 (向后兼容)。