Flash floods in the Patagonian Andes: A dendrogeomorphological approach

CASTELLER, A.; STOFFEL, M.; VILLALBA, R.; CRESPO, S.; CORONA, C.

Tucson, Arizona

Conferencia; Ameridendro 2013; 2013

Universidad de Arizona

Flash floods represent significant natural hazards in the Patagonian Andes causing destruction of buildings and infrastructure. In this region, historical records of past events tend to be short, scarce and fragmentary. This lack of information results in a higher regional vulnerability against flash floods. Dendrogeomorphology is an accurate method for spatially and temporally reconstructing torrential processes. Through the analyses of 58 samples collected from Austrocedrus chilensis, Nothofagus dombeyi, and Pseudotsuga menziesii trees, we reconstructed spatio-temporal patterns of flash floods in a torrent located in the province of Neuquén, Patagonian Andes. The tree-ring based chronology of events was then utilized to determine potential triggers of flash floods in the torrent through the analysis of regional climatic data. Since most precipitation typically occurs in the region during the cold season, the altitudinal gradient between the meteorological station and the watershed was considered to infer the type of the precipitation (snow/rainfall) and thus the possibility of occurrence of events.