Debris Flow and Debris Flood Susceptibility Analysis Using GIS and Remote Sensing in The Molina River Sub-Basin, Metropolitan Region, Chile

In the Andean foothills and mountain range at the latitude of the city of Santiago, due to urban growth, landslides have been the most frequent geological-geomorphological hazard affecting the population, infrastructure, and natural systems in recent decades. A debris flow and debris flood susceptibility map was developed based on satellite and cartographic information, analysis of conditioning factors and the use of GIS tools. A total of 14 conditioning factors were considered, grouped into three categories (geology, geomorphology and soil condition). A susceptibility index (SI) was applied, based on the sum of the weighted scores for each of the conditioning factors. In the Molina River sub-basin, 29.39% of the area has high and very high susceptibility, 28.34% has moderate susceptibility and 42.27% has low to very low susceptibility. In central Chile, historical and recent records indicate that landslides have been triggered by extreme precipitation, thermal anomalies, and large earthquakes.