Author(s): Francisco Jose Perez-Latorre; Jose David Moral-Erencia; Santiago Garcia-Siles; Patricio Bohorquez

Linked Author(s): patricio bohorquez

Keywords: IBERPLUS; Saint-Venant; Street-Scale Drainage; Unpaved Road; Distributed-Hydrological Modelling

Abstract: We apply a unified methodology to improve the design and effectiveness of a road drainage system in a steep slope basin. The basis is the Saint-Venant equations, which can reproduce surface water dynamics from the catchment to the drainage system of forest roads. By incorporating multi-core computational facilities as a graphics processing unit (GPU) and the well-balanced finite volume solver IBERPLUS, we simulated the whole system of hydrologic-hydraulic processes. We predicted the behaviour of the drainage system of a forest road network accurately by simulating its response to the design storm numerically. The distributed hydrological software IBERPLUS accurately simulated the hydrology of the catchment, routing the runoff from the basin to the multiple-scale drainage system up to the road and its drainage network. The return periods of the design storm were 25 and 100 years, according to the Spanish Directive FOM/298/2016. The flow depth and velocity were computed at three spatial scales: basin, road and drainage systems. The analysis of the water discharge, flow depth and velocity on the road and the basin allowed the location of the critical stretches showing overtopping and sedimentation. About 10% of existing culverts were undersized for the 100-yr return period. Under culvert sedimentation, the undersized drainage elements increased up to 40%. In recent rainfalls, slackwater sediments settled on the exact road locations predicted by the simulation. These findings point to the need to incorporate new methodologies based on the simulation of hydrologic-hydraulic processes with the Saint-Venant equations to ensure a safe design of the transport network. This work was funded by PINUS S.A, “Programa Operativo FEDER 2014-2020” and “Consejería de Economía y Conocimiento de la Junta de Andalucía” under Grant No. 1380967. J.D.d.M.-E. was supported by a post-doctoral grant from the University of Jaén.

DOI: https://doi.org/10.3850/IAHR-39WC2521711920221719

Year: 2022