Landslides Rainfall One of the Main Triggering Factors in the Mountainous Regions of Puebla, Mexico

Abstract

The rains are one of the main triggers of landslide phenomena in the mountainous region of Puebla, which values reach up 4500 mm/year in some places in this area. Rainfalls combined with other factors such as morphology (mountainous topographic relief with strong inclinations), strongly folded sedimentary rocks (conglomerates, sandstones, siltstones, and limestones), rock discontinuities (fissures, cracks, joints, stratigraphic planes, etc.) and human activity (cuts, excavations, overloads, mining, water discharge, deforestation, land use change, etc.), offer a scenario prone to landslide phenomena that cause human casualties, economic and environmental losses. The landslides disasters have affected many social sectors from these communities (housing, education, health, hydraulic infrastructure, electricity, communication, transportation, public services, agriculture, forestry, etc.), observing that in these sites there are communities of ethnic groups Nahuatls, Totonacs, Otomies and Tepehuas who build their houses out of sheet metal, cardboard, plastic and wood where any natural phenomenon represents a true disaster. This article presents the relationship between hurricanes and torrential rains with the disasters caused in communities in the mountainous region of Puebla. From the analysis of the data obtained from the different meteorological stations installed in the region of interest during a period of 20 years (1999 – 2019), an empirical rainfall threshold of 100 mm/day was determined as a trigger for landslides in the region of study. The aforementioned value is very important data for Civil Protection Government Authorities in order to establish actions and strategies for mitigation and risk management due to landslides. From this rain threshold, evacuation actions are put into operation to reduce the vulnerability of exposed and fragile communities which are immediately transferred to protection shelters