Project aim

Quantify how much of Obuasi Municipal District lost vegetation between 2018 and 2024, and where that loss is concentrated.

  • 32.0%District in decline
  • 9.2%Strong decline
  • 22.8%Moderate decline
  • 7 yrsTime series
Illustrative map for Obuasi Vegetation Decline Illustrative graphic

Overview

Built end-to-end with pygeofetch, this case study analyses a boundary-clipped USGS Landsat NDVI time series for 2018 to 2024. It finds 32.0% of the district in measurable vegetation decline (9.2% strong and 22.8% moderate), spatially concentrated around mining activity.

The challenge

Year-to-year NDVI varies with rainfall and acquisition dates, so single-image comparisons exaggerate or hide change. A trend over the full series, clipped to the official district boundary, gives a figure local stakeholders can use.

Data & inputs

  • USGS Landsat (2018 – 2024)
  • District boundary

Approach

  1. 01

    Data acquisition

    USGS Landsat scenes for 2018 to 2024 were searched and downloaded with pygeofetch.

  2. 02

    Boundary clipping

    All rasters were clipped to the Obuasi Municipal District boundary.

  3. 03

    NDVI time series

    NDVI was computed for each scene and assembled into a per-pixel time series.

  4. 04

    Trend classification

    Per-pixel trends were classified into strong decline, moderate decline and stable or increasing.

Results

32.0% of the district shows measurable vegetation decline, spatially concentrated around mining activity.

Validation

Reproducible notebook using public Landsat data.