Du är här

Long term NOAA-AVHRR GIMMS-NDVI - rainfall relationships and trends 1981 to 2003 for entire DeSurvey area of interest

Författare:
  • Christian Töttrup (PhD)
  • Ulf Helldén (Professor)
Redaktör:
  • Ulf Helldén (Professor)
Publiceringsår: 2007
Språk: Engelska
Sidor: 108
Publikation/Tidskrift/Serie: FP6, DeSurvey IP, Sub-deliverable 1.5.1.17 (1), Deliverables data base
Dokumenttyp: Rapport
Förlag: DeSurvey IP & Department of Physical Geography and Ecosystems Analysis

Sammanfattning

The paper presents results of a study on the use of the NOAA AVHRR data for desertification monitoring on a regional-global level. It is based on processing of the GIMMS 8 km global NDVI data set. Time series of annual integrated NDVI and standardized annual NDVI anomalies from the 1981-2003 periodic means were compared with a corresponding rainfall data set (i.e. 1981-2003) as well as a historical rainfall set (1901-2002). Both sets were derived from 2.5 degrees and 0.5 degrees global gridded climate data respectively.

The areas studied include the Mediterranean basin (Southern Europe and Northern Africa), the Sahel from the Atlantic to the Red Sea, major parts of the drylands of Southern Africa, China and the drylands of South America, i.e. important parts of the desertification prone areas of the world (Cf. fig. 1)

It is concluded that the suggested methodology is a robust and reliable way to assess and monitor desertification on a global, national and regional scale. The results of the applied methodology indicate a strong general relationship between NDVI and rainfall over time. The results of performed trend analysis cannot be used to verify any systematic generic land degradation/desertification trend at the regional-global level in any of the regions studied. On the contrary, a “greening-up” seems to be evident over the past 20 years in several of the regions when interpreting the NDVI as a proxy for biomass cover and seasonal vegetation growth.

This is most obvious in the African Sahel region south of the Sahara.

Disputation

Nyckelord

  • Earth and Environmental Sciences
  • Remote sensing
  • land degradation
  • global biomass monitoring
  • desertification

Övriga

  • EU DG Research
Published
  • FP6, DeSurvey IP 2005-2010, A Surveillance System for Assessing and Monitoring Desertification
FP6, DeSurvey IP, Sub-deliverable 1.5.1.17 (1)
  • EU FP6 DeSurvey WP 1.5.1: RS & Geomatics-Land condition assessment, Regional trends
  • EU FP6 DeSurvey Project No.: 003950

Box 117, 221 00 LUND
Telefon 046-222 00 00 (växel)
Telefax 046-222 47 20
lu [at] lu [dot] se

LERU logotype U21 logotype

Fakturaadress: Box 188, 221 00 LUND
Organisationsnummer: 202100-3211
Om webbplatsen