Geomorphologic index validation by DINSAR technique in the Andean orogenic front (32°- 33°S)

摘要

This paper deals with a morphotectonic characterization of the Mendoza piedmont located in the South edge of the Andean Precordillera (32 degrees - 33 degrees S) very close to Mendoza city where at least 800.000 people habits. Marked tectonic geomorphological expressions exist in this area associated with the Andean Orogenic active front showing historical earthquakes with magnitudes from 6.0 to 7.0. The main objective of this work is the understanding of current deformation on the study area by two indirect and complementary methods: analysis of classic morphometric parameter (H index), and calculation of deformation fields by DINSAR technique. Applying morphometric analysis of drainage basins of the Mendoza piedmont, heterogenetic hypsometric values (H) were found as probable response to different dynamic relations with base level of the fluvial drainage system. This segmentation on piedmont behaviour allows us to discriminate three different areas (Northern, Central, and Southern). On the basis of morphological criteria, the Southern area reveals a greater tectonic activity matching with a greater vertical deformation inferred by DINSAR technique. These findings improve the knowledge about regional seismic hazard allowing release where main deformation is currently being accumulated in the Andean active front.