Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Skip to content
  • Feedback

    • Woody and Herbaceous Vegetation Change across the Savannas of West Africa, 1982-2013

    Metadata Updated: December 7, 2023

    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.

    Access & Use Information

    Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Created Date September 27, 2023
    Metadata Updated Date December 7, 2023

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Graphic Preview

    Concurrent woody and herbaceous vegetation changes between the 1982-1991 and 2004-2013 decades of the Sudano-Sahel region of Africa. (A) Map of vegetation change categories. (B) Chart showing the conceptual position and the relative abundance of each category in a 2-D space (Anchang et al. 2019).

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date September 27, 2023
    Metadata Updated Date December 7, 2023
    Publisher ORNL_DAAC
    Maintainer
    Identifier C2764722720-ORNL_CLOUD
    Data First Published 2020-05-07
    Language en-US
    Data Last Modified 2023-09-11
    Category Vegetation, geospatial
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Metadata Catalog ID https://data.nasa.gov/data.json
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Citation Anchang, J.Y., L. Prihodko, A.T. Kaptue, C.W. Ross, W. Ji, S.S. Kumar, B. Lind, M.A. Sarr, A.A. Diouf, and N.P. Hanan. 2020. Woody and Herbaceous Vegetation Change across the Savannas of West Africa, 1982-2013. ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/1738
    Graphic Preview Description Concurrent woody and herbaceous vegetation changes between the 1982-1991 and 2004-2013 decades of the Sudano-Sahel region of Africa. (A) Map of vegetation change categories. (B) Chart showing the conceptual position and the relative abundance of each category in a 2-D space (Anchang et al. 2019).
    Graphic Preview File https://daac.ornl.gov/VEGETATION/guides/WAVeTrends_Fig1.png
    Harvest Object Id 46dd7607-372a-459d-965b-315492a52a4c
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://doi.org/10.3334/ORNLDAAC/1738
    Metadata Type geospatial
    Old Spatial -17.14 9.96 15.31 17.41
    Program Code 026:001
    Source Datajson Identifier True
    Source Hash 47cc077215a2fccde8af13ff1d75e1c5072e5316cfad063676cbc238a737b485
    Source Schema Version 1.1
    Spatial
    Temporal 1982-01-01T00:00:00Z/2013-12-31T23:59:59Z

    Didn't find what you're looking for? Suggest a dataset here.