Landslide Community Mapping and Public Awareness in the Region of Chichonal Volcano, Chiapas, Mexico

Abstract

The Chichonal is an active volcano situated in the North of Chiapas State, in the Southeast of Mexico; 60 km to the Southeast of Villahermosa, State of Tabasco and 70 km to the Northeast of Tuxtla Gutierrez, the capital of the State of Chiapas. The region comprises important areas of eight municipalities, some of them still inhabited by Zoque indigenous population.

The last eruption of Chichonal volcano occurred in 1982. Non-consolidated volcanic deposits derived from this period of activity are very susceptible to the occurrence of landslides. Landsliding frequently takes place during the rainy season (April–October) and also are associated with floods, although high seismicity is common in the region. What is more, lithological units such as sandstones, lutites and limestones are susceptible to landsliding too.

By means of participatory cartography, and based on the communities experience, residents of the municipalities situated around the Chichonal volcano developed different general landslide hazards maps. Additionally, a landslide susceptibility map was generated by means of weights of evidence using GIS. The later, considered physical variables including geological and geomorphological features.

According to the produced map, the eastern sector is the most susceptible area for landslides since slopes are high and there is a presence of ancient landslides on limestones and lutites. In the western area, there are also some strips of landslide susceptibility on high slopes formed by sandstones and lutites. Moreover, in this same area, potential lahars can also take place along the gullies on the Chichonal volcanic edifice.

In this paper, we present the experiences of landslide community mapping in the region of Chichonal volcano that took place within the context of a series of workshops that were organised in order to raise landslides public awareness.