ABSTRACT
For a long time, agricultural monitoring systems have been using space remote sensing (RS) instruments to provide timely and synoptic information about drought. A variety of approaches are currently being used and most of them are based on the analysis of RS data in the optical domain. They permit the mapping of vegetation vigor, as well as hydrological variables such as rainfall and evapotranspiration when using imagery in the thermal domain. Sensors operating in the microwave domain provide additional and valuable information regarding soil moisture. In this chapter, after providing background information about drought-monitoring indices and systems in general, we focus on the current use of satellite-derived biophysical indicators of vegetation status from RS in the optical domain.
