Studies in Surveying and Mapping Science (SSMS) Volume 3, 2015 www.as-se.org/ssms 1 Satellite-Image Based Analysis of Vegetation Affected by Volcanic Ash Deposits – Case Study at Cordón Caulle (Chile) Guido Staub *1 , Irlanda Mora 2 , Henry Montecino 3 , Juan Carlos Báez 4 1,2,3 Departamento de Ciencias Geodésicas y Geomática, Universidad de Concepción – Campus Los Ángeles, J. A. Coloma 0201, Los Ángeles, Chile 4 Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Blanco Encalada 2002, Santiago, Chile *1 gstaub@udec.cl; 2 irlanda.mora.rosales@gmail.com; 3 henrymontecino@gmail.com; 4 jcgeodesy@gmail.com Abstract In recent years, a series of volcanic eruptions occurred in Chile, affecting flora, fauna and human beings. Space borne monitoring of the environment affected by volcanic ash deposits is a major task in order to determine recuperation processes. The objective of this paper is to study vegetation affected by volcanic ash deposits using a combined multi-temporal – multi- spectral image analysis approach applied to the volcanic complex Puyehue - Cordón Caulle. An annual survey based on Landsat 7 ETM+ satellite images was carried out. Special focus was given on three specific test sites where ground-truthing was possible and reference data was accessible. Our results indicate that not only ash covered vegetation reduced, but also its photosynthetic activity started to develop when ash emission decreased. In this particular case we conclude that the possibility for vegetation recovery depends mostly on winds, precipitation and landform of the study sites. Keywords Remote Sensing; Vegetation; NDVI; Volcanic Eruption Introduction Located 83 kilometers northeast of the city of Osorno, the so-called Volcanic Complex Puyehue - Cordón Caulle VCPCC, see figure 1, which corresponds to a volcano-tectonic depression (that is about 13 km long and 4 km wide), has a number of monogenetic volcanic centers, including pumice cones, lava domes, volcanic fissures and the largest geothermal center of southern volcanic zone of Chile (Sepúlveda et al. [24]). The Caldera Cordillera is a collapsed stratovolcano of the Pleistocene and is located at the northwest boundary of the volcanic complex, while the Puyehue stratovolcano is located in the southwest (as shown by Katsui and Katz [11], Campos et al. [2], Lara et al. [15], Lara et al. [16] and Lara et al. [17]). FIG. 1 VCPCC SHOWN AS ALI HIGH-RESOLUTION IMAGE; OBSERVED OCTOBER 22, 2011 (IMAGE COURTESY BY EARTHOBSERVATORY.NASA.GOV) 40° 34' 57''S ––– 72° 06' 42''W