Landslide Hazard Mapping and Evaluation of the Comayagua Region, Honduras

Abstract

The central region of Honduras was strongly affected by the hurricane Mitch in October 1998. This disaster put in evidence the abundance of large sub-active landslides whose acceleration or reactivation caused important human losses and damages to infrastructure. In the same way, most of the thousands of debris flow and rock falls induced by the intense rainfalls were related to this type of landslides. In this region we also discovered the one that up to now consider the largest instability phenomenon in Latin America: the Ajuterique-Playón landslide, which area surpasses 25 km². The most of the large scale landslides have been developed mainly in Cretaceous calcareous formations and in the Tertiary volcanic formations. In some areas it the substratum of red layers or sedimentary rocks of continental origin (sandstones and lutites) is also involved, as well as the Paleozoic metamorphic rocks. The results of a preliminary landslide hazard mapping and evaluation carried out between 2000 and 2003 are presented here, including a general appreciation of the danger levels they represent.