🔥 Prescribed Fire Boundary Mapping — Google Earth Engine

Remote sensing scripts for mapping prescribed fire boundaries at Texas nature preserves using satellite imagery. Developed during a science internship with The Nature Conservancy — Texas Chapter.

What it does

The scripts calculate the Normalized Burn Ratio (NBR) and differenced NBR (dNBR) from satellite imagery captured before and after a controlled burn. This allows ecologists to:

• Identify which areas within a preserve were actually burned
• Assess burn severity using USGS classification thresholds
• Export fire boundary polygons as shapefiles for land management records
• Monitor post-fire vegetation recovery using NDVI (Sentinel-2 script)

Scripts

File	Satellite	Resolution	Best for
landsat8_nbr.js	Landsat 8 (NASA/USGS)	30m	Historical burns (2013+), large preserves
sentinel2_nbr.js	Sentinel-2 (ESA)	10m	Recent burns (2017+), finer detail

How to use

1. Open the Google Earth Engine Code Editor
2. Paste the contents of either .js file into a new script
3. Set the configuration variables at the top:
   • PRESERVE_NAME — must match the Interest_N field in your asset
   • Date ranges for before and after the burn
4. Click Run
5. Uncomment the Export block to save fire polygons to Google Drive

Techniques used

• NBR: (NIR - SWIR) / (NIR + SWIR) — highlights burned areas
• dNBR: difference between pre- and post-fire NBR for burn severity classification
• NDVI: tracks vegetation health for post-fire recovery monitoring
• Cloud masking: QA60 bitmask for Sentinel-2, metadata filtering for Landsat 8

Sites mapped

• Clymer Meadow Preserve (October 2013) — Landsat 8
• Roy E. Larsen Sandyland Sanctuary (March 2023) — Sentinel-2