Numerical Modeling of Flow Patterns Applied to Analysis of Susceptibility to Movements of the Ground

Marcelo Cando Jácome,Antonio Martínez-Graña

doi:10.3390/geosciences8090340

Marcelo Cando Jácome, Antonio Martínez-Graña

Open Access

https://doi.org/10.3390/geosciences8090340

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Journal: Geosciences	Publication Date: Sep 9, 2018
Citations: 5	License type: CC BY 4.0

Affiliation: Universidad de Salamanca

Abstract

Mass movements in deformed areas of natural relief deformed by seismotectonic factors are one of the most destructive and recurrent natural hazards in the Republic of Ecuador, especially during intense rain periods, the El Niño phenomenon, or due to earthquakes such as the one that occurred on 16 April 2016 in the Ecuadorian coastline. This study proposes the application of Hydrological Model D8 and its derived morphometric parameters like slope, orientation of the slope, and curvatures, extracted from the high spatial resolution Digital Elevation Model (DEM), implemented in programs such as Rockworks 7 (gridzo), SURFER (downwards slope), ArcView (flowacc), and SAGA (curvatures) to obtain runoff flow, structural geological lineaments, and superficial deformations of the topographic relief that are the origin of erosion, superficial landslides, lateral propagation, of the rock–soil complex, mass flows, and deep gravitational deformations. This methodology has been validated in three locations with intense deformations: two in Ecuador and one in Spain. The DEM were obtained from the Ecuadorian Spatial Institute (ESI) (spatial resolution of 10 m), the Rural Technological Infrastructure and Information National System (SIGTIERRAS) (spatial resolution of 5 m), and the Council of Andalusia (spatial resolution of 5 m).

Highlights

Mass movements in Ecuador are one of the biggest threats that cause recurring disasters, especially during the periods of intense anomalous rains, the El Niño phenomenon, and earthquakes such as the one that occurred on April 16, 2016 in the Ecuadorian coastline.In 2010, with the creation of the National Secretariat for Risk Management (SNGR), a standardized methodology was developed to elaborate mass movements’ susceptibility maps at a municipal level in the entire country using a 1:50,000 scale
Based on the need to find these origins in better detail, the methodologic proposal was developed in relation to the outline of flow lines belonging to the superficial runoff of precipitation water as a mass pusher, structural geological lineaments, fractures, and deformations of the topographic relief from high mountainous areas, intermediate, and lower topographic areas
The numerical method applied is based on the theoretical principles of the D8 Hydrological Model, using Digital Elevation Models (DEM)

Summary

Introduction

Mass movements in Ecuador are one of the biggest threats that cause recurring disasters, especially during the periods of intense anomalous rains, the El Niño phenomenon, and earthquakes such as the one that occurred on April 16, 2016 in the Ecuadorian coastline. Studies that served to understand the basic concepts of digital terrain models (DTM), emphasizing the definition, structure, and errors of the construction of the DEM, as well as its applications in the characterization of reliefs, preparation of topographic profiles, visualization and drainage of hydrographic basins, and elaborations of flow lines using the hydrological model D8 as a basic model. The results of this investigation were presented in the First International Symposium of Mass.

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