GSA Annual Meeting in Seattle, Washington, USA - 2017

Paper No. 59-9
Presentation Time: 4:15 PM

AN OVERVIEW OF A GIS METHOD FOR LANDSLIDE MAPPING, ASSESSING LANDSLIDE SUSCEPTIBILITY, AND ESTIMATION OF LANDSLIDE SEDIMENT YIELDS ON THE SE FLANK OF PICO DE ORIZABA VOLCANO, MEXICO


LEGORRETA PAULIN, Gabriel, Departamento de Geografía Física, Universidad Nacional Autónoma de México, Av. Universidad # 3000, Col. UNAM, C.U., Del. Coyoacán, C.P. 04510, Cd. Mex. UNA290722 7Y1, Mexico city, 04510, Mexico, BURSIK, Marcus I., Geology, University at Buffalo, 411 Cooke Hall, Buffalo, NY 14260, CONTRERAS, Trevor, Washington Geological Survey, Washington State, Department of Natural Resources, 1111 Washington Street SE Olympia, WA 98501, Olympia, WA 98501 and POLENZ, Michael, Washington Department of Natural Resources, Washington Geological Survey, 1111 Washington St SE, MS 47007, Olympia, WA 98504-7007, legorretag@hotmail.com

Landslides along river systems are very common and have the potential to cause harm to humans and infrastructure. This is especially true for steep volcanic terrains covered by poorly consolidated materials which are affected by high seasonal rainfall and anthropogenic activities (such as deforestation and land use changes). Our use of a Geographic Information System (GIS) in the study of landslides in volcanic terrains (PAPIIT # IN102115 project) has permitted development of a comprehensive method for landslide mapping, landslide susceptibility mapping, and landslide volume estimation.

The Río El Estado watershed on the SE flank of Pico de Orizaba volcano covers 5.2 km2 with elevations ranging from 2,677 to 4,248 m a.s.l. and slopes between 5° and 68°. The stream system of El Estado erodes Tertiary and Quaternary lavas, pyroclastic flows, and ash fall deposits. Geologic and geomorphologic factors, high seasonal precipitation, severe weathering, and steep slopes predispose the study area to landslides. The methodology encompasses three main stages of analysis: Stage 1 builds a historic landslide inventory and its spatial geo-database based on aerial-photo-interpretation and local field surveys.

Stage 2 calculates and compare the landslide susceptibility by using heuristic (per landforms), statistic (Multiple Logistic Regression), and cartographic-hydrologic (SINMAP) methods.

Stage 3 estimates the potential total landslide material volume delivered to the main stream drainage channel by using an empirical area-volume relationship.

We estimate that landslides have the potential to deliver 27,677,303 m3 of sediment to the main stream, 83% of this volume is contributed by high susceptibility landforms. We present the technique and its implementation of each stage in GIS. The results allow us to understand the long-term evolution of the fluvial system on southwestern flank of Pico de Orizaba.