Author(s): J. W. Cabrera Cabrera; L. F. Castillo Navarro

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Keywords: Debris flow; Flexible barriers; Floods; Sabo dam; Vulnerability

Abstract: Coast of Peru is characterized for the presence of ephemeral creeks which drain water only on wet season. The extremely dry soil and pebble combined with precipitation produce debris flow in a seasonal geodynamic. This is the case of Santo Domingo ravine which is located at eastern Lima, and drains their water to Rimac River. In this article the vulnerability of villages near to Santo Domingo ravine by debris flow and use of flexible barrier and sabo dams are analyzed. In a first stage, the liquid hydrograph to a 100 years return period was built and a solid hydrograph, a relationship between volume concentration and time, was essayed. Then, both the liquid and the solid hydrograph are calibrated in a debris flow numerical model and the vulnerability map is built. Finally, this model is coupled to the Rimac River to analyze the possible damming effect. Calibration of numerical model was done in base to previous estimated volumes by Japanese International Cooperation Agency (JICA). These first results permit to define high vulnerability zones which will be a reference to evaluate efficiency of control measures. In a second stage, mitigation effects of flexible barriers application is simulated in base to Debris Flow Barrier from Geobrugg®. Also, application of sabo dams was evaluated to by using “Kanako” debris flow simulator from Laboratory of Erosion Control, Division of Forest Science, Graduate School of Agriculture, Kyoto University, & SABO Technical Center. Results permit to evaluate efficiency and select the more economical option.

DOI: https://doi.org/10.15142/T3220628160853

Year: 2016