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Lars Eklundh

Professor

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Analysing vegetation changes in the Sahel using sensor data from Landsat and NOAA

Författare

  • Lars Eklundh
  • Martin Sjöström

Summary, in English

The semi-arid Sahel zone of Africa has suffered several periods of severe drought since about 1950. We have analyzed AVHRR Normalized Difference Vegetation Index (NDVI) over the Sahel for the period 1982-2002, and found extensive areas of increasing NDVI. To verify these changes we have analyzed Landsat TM and ETM+ scenes from 1984-1986 and 1999-2001 for areas in the Sudan, Central African Republic, Niger, Mali and Mauritania. Changes in the Landsat data were analysed by visual interpretation and change vector analysis. In areas of positive AVHRR NDVI change the analysis of Landsat data generally showed a transition from barren or sparse vegetation to a denser vegetation cover. Rainfall had increased over the course of time in several of these areas. In some areas visual interpretation indicated an expansion of agricultural land.

Avdelning/ar

  • Institutionen för naturgeografi och ekosystemvetenskap

Publiceringsår

2005-12-01

Språk

Engelska

Dokumenttyp

Konferensbidrag

Ämne

  • Physical Geography

Nyckelord

  • Africa
  • Change vector analysis
  • Landsat
  • NOAA NDVI
  • Sahel
  • Vegetation change

Conference name

31st International Symposium on Remote Sensing of Environment, ISRSE 2005: Global Monitoring for Sustainability and Security

Conference date

2005-06-20 - 2005-06-24

Conference place

St. Petersburg, Russian Federation

Aktiv

Published