Drought Variability and Land Degradation in Semiarid Regions: Assessment Using Remote Sensing Data and Drought Indices (1982–2011)

Remote Sensing

Sergio M. Vicente-Serrano³  Daniel Cabello²  Miquel Tomás-Burguera⁴  Natalia Martín-Hernández³  Santiago Beguer໚⁴  Cesar Azorin-Molina³  Ahmed El Kenawy⁵  Arnon Karnieli¹  Soe Myint¹ 

[1] Instituto Pirenaico de Ecología, Spanish National Research Council (IPE-CSIC), Campus de Aula Dei, P.O. Box 13034, E-50059 Zaragoza, Spain;;Department of Economy, University of Alcala, E-28801 Madrid, Spain; E-Mail:;Instituto Pirenaico de Ecología, Spanish National Research Council (IPE-CSIC), Campus de Aula Dei, P.O. Box 13034, E-50059 Zaragoza, Spain; E-Mails:;Estación Experimental de Aula Dei, Spanish National Research Council (EEAD-CSIC), Campus de Aula Dei, P.O. Box 13034, E-50059 Zaragoza, Spain; E-Mails:;Hydrological Modeling & Earth Observation Group, WDRC, King Abdullah University of Science and Technology, 23955-6900 Thuwal, Saudi Arabia; E-Mail:

关键词: Standardized Precipitation Evapotranspiration Index (SPEI);    NDVI;    NOAA-AVHRR;    GIMMS;    desertification;    vegetation recovery;   

DOI  :  10.3390/rs70404391

来源: mdpi

【 摘 要 】

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 (NDVI_max) predominantly showed a positive evolution in the majority of the semiarid regions assessed, but NDVI_max was highly correlated with drought variability, and the trends of drought events influenced trends in NDVI_max at the global scale. The semiarid regions that showed most increase in NDVI_max (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 NDVI_max. 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.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.