Vicente-Serrano, S. and Cabello, D. and Tomás-Burguera, M. and Martín-Hernández, N. and Beguería, S. and Azorín-Molina, C. and Kenawy, A. (2015) Drought Variability and Land Degradation in Semiarid Regions: Assessment Using Remote Sensing Data and Drought Indices (1982–2011). Remote Sensing, 7 (4). pp. 4391-4423. ISSN 2072-4292
Full text not available from this repository.Abstract
We analyzed potential land degradation processes in semiarid regions worldwide using long time series of remote sensing images and the Normalized Difference Vegetation Index (NDVI) for the period 1981 to 2011. The objectives of the study were to identify semiarid regions showing a marked decrease in potential vegetation activity, indicative of the occurrence of land degradation processes, and to assess the possible influence of the observed drought trends quantified using the Standardized Precipitation Evapotranspiration Index (SPEI). We found that the NDVI values recorded during the period of maximum vegetation activity (NDVImax) predominantly showed a positive evolution in the majority of the semiarid regions assessed, but NDVImax was highly correlated with drought variability, and the trends of drought events influenced trends in NDVImax at the global scale. The semiarid regions that showed most increase in NDVImax (the Sahel, northern Australia, South Africa) were characterized by a clear positive trend in the SPEI values, indicative of conditions of greater humidity and lesser drought conditions. While changes in drought severity may be an important driver of NDVI trends and land degradation processes in semiarid regions worldwide, drought did not apparently explain some of the observed changes in NDVImax. This reflects the complexity of vegetation activity processes in the world's semiarid regions, and the difficulty of defining a universal response to drought in these regions, where a number of factors (natural and anthropogenic) may also affect on land degradation.
| Item Type: | Article |
|---|---|
| Subjects: | G Geography. Anthropology. Recreation > GE Environmental Sciences |
| Depositing User: | José Ángel Gómez Martín |
| Date Deposited: | 05 Aug 2015 08:17 |
| Last Modified: | 15 Oct 2015 15:23 |
| URI: | http://eprints.imdea-agua.org:13000/id/eprint/505 |
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