Get access

Impact of climate variability on vegetative cover in the Butana area of Sudan

Authors

  • Muna Elhag,

    1. Department of Soil, Crop, Climate Sciences, Faculty of Natural and Agricultural Sciences, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
    2. Department of Agricultural Engineering, Faculty of Agricultural Sciences, University of Gezira, PO Box 20, WadMedani, Sudan
    Search for more papers by this author
  • Sue Walker

    Corresponding author
    1. Department of Soil, Crop, Climate Sciences, Faculty of Natural and Agricultural Sciences, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
    Search for more papers by this author

*E-mail: walkers.sci@ufs.ac.za

Abstract

Climate variability has an impact on the renewable natural resources. This impact is strong in regions with a delicate balance between climate and ecosystem, like the Sahelian regions. Rainfall is the most important climatic factor influencing livelihoods in Butana, north-eastern part of Sudan. All people and their livestock depend on the amount of rainfall that falls and supports plant growth. Butana area experienced severe drought in 1984, 1990 and 2000. Linear relationships between the long-term rainfall and AVHRR/NDVI data were developed for four separate zones in the Butana area. There is a significant correlation between peak NDVI (beginning of September) and cumulative rainfall for July and August, but weak relationships resulted when annual rainfall and cumulative NDVI were used. This is because the NDVI reached a plateau as the rainfall increased, then it remained constant despite further increases in rainfall. The departure from the long-term average of NDVI for each pixel was calculated using the departure average vegetation method. The area had a high percentage of departure during the drought years and the NDVI recovered during the following year when the rainfall was above the average. It can be noted that the area adjacent to the irrigated scheme showed considerable decrease in NDVI. This may be due to overexploitation by the nomads during the drought year.

Ancillary