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 January 13, 2026, 03:57 (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 c2eefd2b-b06c-48d7-9cf9-eda829c16e96
harvest_source_id b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title Science Discovery Engine
identifier 10.3334/ORNLDAAC/1738
landingPage https://search.earthdata.nasa.gov/search?q=WAVeTrends_1738&ac=true
modified 2026-01-12
programCode {026:000}
publisher ORNL_DAAC
resource-type Dataset
source_datajson_identifier true
source_hash 27ba21505c10962c0a44e9fcc8b679691a588aadd88a3ed8328085c5e1bcda8e
source_schema_version 1.1
spatial [[{"WestBoundingCoordinate":-17.1432,"NorthBoundingCoordinate":17.4148,"EastBoundingCoordinate":15.3068,"SouthBoundingCoordinate":9.96476}],"CARTESIAN"]
temporal 1982-01-01/1982-01-01
theme {"Earth Science"}