Investigating natural hazards in the peruvian region of nasca with space-borne radar sensors

Abstract

ENVISAT ASAR IS2 C-band imagery from the European Space Agency (ESA) archive was processed over the Peruvian region of Nasca, to investigate landscape modifications and dynamics of natural hazards and surface processes. Changes of radar backscattering (σ0) were computed for the period 2003–2007, and the temporal evolution of the Rio Grande drainage basin was assessed. ASAR amplitude information rather than coherence and phase, was exploited to monitor environmental changes that may cause detrimental effects on natural and cultural heritage. The comparison of multi-platform satellite imagery allowed the detection of aqueduct systems (the so-called ‘puquios’) designed by ancient Paracas and Nasca Civilizations (fourth century BC to sixth century AD) for water collection and supply.