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.

Data and Resources

Additional Info

Field Value
Maintainer Earthdata Forum
Last Updated September 15, 2026, 04:29 (UTC)
Created April 1, 2025, 20:03 (UTC)
accessLevel public
bureauCode {026:00}
catalog_conformsTo https://project-open-data.cio.gov/v1.1/schema
harvest_object_id 6dd74830-4e9d-4b06-9c95-91de81978f00
harvest_source_id b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title Science Discovery Engine
identifier 10.3334/ORNLDAAC/1738
license https://www.usa.gov/government-works
modified 2026-09-07T22:16:03Z
programCode {026:000}
publisher ORNL_DAAC
resource-type Dataset
source_datajson_identifier true
source_hash 431fd4da391869fc64c00cd36bedd21f892ad468fb09d3a29bc2d82b0a5b6a52
source_schema_version 1.1
spatial ["CARTESIAN", [{"WestBoundingCoordinate": -17.1432, "NorthBoundingCoordinate": 17.4148, "EastBoundingCoordinate": 15.3068, "SouthBoundingCoordinate": 9.96476}]]
temporal 1982-01-01/2013-12-31
theme {"Earth Science"}