Evaluación de la susceptibilidad de deslizamientos en el río El Estado, Puebla-Veracruz, México

Abstract

This work introduced and reviewed the elaboration of landslide susceptibility car-tography by using SINMAP model. This entailed a review of cartographic material, (compilation of a landslides inventory), the modeling of susceptibility and its sub-sequent validation. The study area was the sub-basin of the El Estado River, on the southern slope of the Pico de Orizaba volcano. The inventory records 113 landslides, 68 were debris slides, wich represent 60% of the total, 20 were debris flow (18%), five were debris avalanche (4%), and four were rock falls (4%), belonging to the translational type and 16 were deep-seated landslides (14%), belonging to the rotational type. They had occurred on slopes, on either banks of the river. The SINMAP model use geotechnical properties (internal friction angle, cohesion and infiltration) and cartographic and hydrological properties (slope, altimetry, runoff, precipitation, and capture area) of the average of 19 sampling points within the sub-basin. Qualitatively, (the sectors that show zones of stability in the model are intermingle with each other in a large part of the sub-basin). The unstable zone extends over a large portion of the upper part of the sub-basin, whereas in the lower part it is limited to the slopes of the channel. Adjacent to the unstable zone, are the zones of the lowest and highest stability, without the presence of zones of intermediate stability. Quantitatively, there is a low concordance between the inventory and the model and there is an over-prediction of areas with landslides. This is obtained from derived statistics (global, producer and user precision) of an error Matrix. The results imply that the SINMAP model is partially reliable in the evaluation of susceptibility to landslides in volcanic areas of Mexico.