About this example
Land-cover change matrices from remote sensing are a natural fit for alluvial diagrams: each class is a category, each survey year is a stage, and flow widths are areas rather than counts.
Using conventional class colors (green for forest, yellow for cropland, gray for urban, blue for water) lets readers recognise categories without a legend. Decimal values are supported, so areas can be entered exactly as measured.
The data
| 2000 | 2010 | 2020 | Area (km²) |
|---|---|---|---|
| Forest | Forest | Forest | 412.5 |
| Forest | Forest | Cropland | 38.2 |
| Forest | Cropland | Cropland | 64.8 |
| Forest | Grassland | Cropland | 12.4 |
| Forest | Forest | Urban | 5.1 |
| Cropland | Cropland | Cropland | 280.3 |
| Cropland | Cropland | Urban | 41.7 |
| Cropland | Urban | Urban | 22.9 |
| Cropland | Grassland | Forest | 9.6 |
| Grassland | Grassland | Grassland | 96.4 |
| Grassland | Cropland | Cropland | 33.1 |
| Grassland | Forest | Forest | 14.8 |
| Urban | Urban | Urban | 58 |
| Water | Water | Water | 71.2 |
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