# SPH Modeling of Water-Related Natural Hazards

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Department of Civil Engineering and Architecture, University of Pavia, via Ferrata 3, 27100 Pavia, Italy

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Department of Civil & Environmental Engineering, National University of Singapore, 21 Lower Kent Ridge Road, Singapore 119077, Singapore

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EPHYSLAB Environmental Physics Laboratory, Universidade de Vigo, AS LAGOAS-32004, Ourense, Spain

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State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300072, China

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Department SFE, Ricerca sul Sistema Energetico—RSE SpA, via Rubattino 54, 20134 Milan, Italy

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School of Engineering, University of Basilicata, 85100 Potenza, Italy

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Author to whom correspondence should be addressed.

Received: 4 July 2019 / Revised: 3 September 2019 / Accepted: 6 September 2019 / Published: 9 September 2019

(This article belongs to the Special Issue Advances in Modelling and Prediction on the Impact of Human Activities and Extreme Events on Environments)

This paper collects some recent smoothed particle hydrodynamic (SPH) applications in the field of natural hazards connected to rapidly varied flows of both water and dense granular mixtures including sediment erosion and bed load transport. The paper gathers together and outlines the basic aspects of some relevant works dealing with flooding on complex topography, sediment scouring, fast landslide dynamics, and induced surge wave. Additionally, the preliminary results of a new study regarding the post-failure dynamics of rainfall-induced shallow landslide are presented. The paper also shows the latest advances in the use of high performance computing (HPC) techniques to accelerate computational fluid dynamic (CFD) codes through the efficient use of current computational resources. This aspect is extremely important when simulating complex three-dimensional problems that require a high computational cost and are generally involved in the modeling of water-related natural hazards of practical interest. The paper provides an overview of some widespread SPH free open source software (FOSS) codes applied to multiphase problems of theoretical and practical interest in the field of hydraulic engineering. The paper aims to provide insight into the SPH modeling of some relevant physical aspects involved in water-related natural hazards (e.g., sediment erosion and non-Newtonian rheology). The future perspectives of SPH in this application field are finally pointed out.