Woody and Herbaceous Vegetation Change across the Savannas of West Africa, 1982-2013
The WAVeTrends dataset is a 0.05 degree (5.55 km) vegetation change product, spanning the West African Sudano-Sahel region. It provides pixel-wise information on concurrent woody and herbaceous vegetation trends over a 32-year period (1982-2013). Change in woody vegetation was derived using long-term rain use efficiency (RUE) sensitivity, i.e., the per-pixel comparison of the difference of mean RUE between the first and last decades of the 32-year time series. Herbaceous vegetation change was defined by short-term RUE sensitivity, i.e., comparing the slope of the RUE relationship (productivity vs. precipitation) between both decades using per-pixel Analysis of Covariance (ANCOVA). Categorical vegetation change was then determined for each pixel using the direction of the change and a significance level of p<0.05. The use of RUE (the amount of biomass produced per unit of precipitation) for vegetation trend analysis in savanna regions relies on the assumption that rainfall is a significant positive driver of net production in drylands. Testing of this long-term productivity-rainfall relationship revealed that the assumption was not always met, therefore, validity flags are included for each pixel location.
Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | public |
| bureauCode |
[
"026:00"
]
|
| contactPoint |
{
"fn": "Earthdata Forum",
"@type": "vcard:Contact",
"hasEmail": "mailto:earthdata-support@nasa.gov"
}
|
| description | The WAVeTrends dataset is a 0.05 degree (5.55 km) vegetation change product, spanning the West African Sudano-Sahel region. It provides pixel-wise information on concurrent woody and herbaceous vegetation trends over a 32-year period (1982-2013). Change in woody vegetation was derived using long-term rain use efficiency (RUE) sensitivity, i.e., the per-pixel comparison of the difference of mean RUE between the first and last decades of the 32-year time series. Herbaceous vegetation change was defined by short-term RUE sensitivity, i.e., comparing the slope of the RUE relationship (productivity vs. precipitation) between both decades using per-pixel Analysis of Covariance (ANCOVA). Categorical vegetation change was then determined for each pixel using the direction of the change and a significance level of p<0.05. The use of RUE (the amount of biomass produced per unit of precipitation) for vegetation trend analysis in savanna regions relies on the assumption that rainfall is a significant positive driver of net production in drylands. Testing of this long-term productivity-rainfall relationship revealed that the assumption was not always met, therefore, validity flags are included for each pixel location. |
| distribution |
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|
| identifier | 10.3334/ORNLDAAC/1738 |
| keyword |
[
"earth-science-ecological-dynamics-biosphere-ecosystem-functions-primary-production",
"earth-science-ecosystems-biosphere-terrestrial-ecosystems-savannas",
"earth-science-habitat-conversion-fragmentation-human-dimensions-reforestation-revegetation",
"earth-science-precipitation-atmosphere-liquid-precipitation-rain",
"earth-science-vegetation-biosphere-vegetation-cover",
"earth-science-vegetation-biosphere-vegetation-index-normalized-difference-vegetation-index-ndvi"
]
|
| landingPage | https://search.earthdata.nasa.gov/search?q=WAVeTrends_1738&ac=true |
| modified | 2026-02-17 |
| programCode |
[
"026:000"
]
|
| publisher |
{
"name": "ORNL_DAAC",
"@type": "org:Organization"
}
|
| spatial |
"[[{"WestBoundingCoordinate":-17.1432,"NorthBoundingCoordinate":17.4148,"EastBoundingCoordinate":15.3068,"SouthBoundingCoordinate":9.96476}],"CARTESIAN"]"
|
| temporal | 1982-01-01/1982-01-01 |
| theme |
[
"Earth Science"
]
|
| title | Woody and Herbaceous Vegetation Change across the Savannas of West Africa, 1982-2013 |
