Drought Variability and Land Degradation in Semiarid Regions: Assessment Using Remote Sensing Data and Drought Indices (1982-2011). - Sergio M. Vicente-Serrano; Daniel Cabello; Miquel Tomás-Burguera; Natalia Martín-Hernández; Santiago Beguería; Cesar Azorin-Molina; Ahmed M. El Kenawy (Remote. Sens., 2015)