Landsat Fractional Land Cover Analysis of Forest Disturbance in Manaus

Manaus, Brazil is the focus of this dataset containing three geospatial image files analyzing forest disturbance from a 2005 squall line. It provides pre- and post-disturbance Landsat 5 images from October 2004 and July 2005, plus a derived image showing changes in nonphotosynthetic vegetation (NPV). The data was processed by the ORNL_CLOUD organization using spectral mixture analysis to study tree mortality.

Use Cases

• Quantifying forest damage by analyzing the NPV difference image to map areas of increased dead vegetation.
• Calibrating remote sensing models for detecting windthrow events using the provided Landsat reflectance images.
• Studying spectral signatures of disturbance by examining the fractional land cover components (GV, NPV, soil, shade).

Strengths

• Provides a direct temporal comparison with two Landsat 5 images spanning a known disturbance event in 2005.
• Uses a defined scientific method (spectral mixture analysis with a pixel purity index algorithm) for deriving fractional land cover.
• Cross-platform presence on NASA Earthdata and Data.gov signals its importance for ecological research.

Limitations

• The dataset is explicitly flagged as having quality questions, missing data, and incomplete documentation.
• Four key intermediate images (SMA results and individual NPV images) are missing, limiting reproducibility.
• Platforms disagree on the last updated date, with one listing 2005-07-29 and another listing 2026-03-13.

Provenance

Source

ORNL_CLOUD

Collection Method

Landsat 5 images processed using spectral mixture analysis (SMA) based on scene-derived end-members.

Time Range

2004-10-14 to 2005-07-29

Freshness

2026-03-13 01:15:52.253240

Geography

Manaus, Brazil (Landsat path 231, row 62).