Valeria V. Krzhizhanovskaya

Flood early warning system: design, implementation and computational modules

We present a prototype of the flood early warning system (EWS) developed within the UrbanFlood FP7 project. The system monitors sensor networks installed in flood defenses (dikes, dams, embankments, etc.), detects sensor signal abnormalities, calculates dike failure probability, and simulates possible scenarios of dike breaching and flood propagation. All the relevant information and simulation results are fed into an interactive decision support system that helps dike managers and city authorities to make informed decisions in case of emergency and in routine dike quality assessment. In addition to that, a Virtual Dike computational module has been developed for advanced research into dike stability and failure mechanisms, and for training the artificial intelligence module on signal parameters induced by dike instabilities. This paper describes the UrbanFlood EWS generic design and functionality, the computational workflow, the individual modules, their integration via the Common Information Space middleware, and the first results of EWS monitoring and performance benchmarks.

Dynamic workload balancing of parallel applications with user-level scheduling on the Grid

This paper suggests a hybrid resource management approach for efficient parallel distributed computing on the Grid. It operates on both application and system levels, combining user-level job scheduling with dynamic workload balancing algorithm that automatically adapts a parallel application to the heterogeneous resources, based on the actual resource parameters and estimated requirements of the application. The hybrid environment and the algorithm for automated load balancing are described, the influence of resource heterogeneity level is measured, and the speedup achieved with this technique is demonstrated for different types of applications and resources.

Simulation of City Evacuation Coupled to Flood Dynamics

Crowd modeling is one of the key components of risk analysis and evacuation planning in emergency situations. This paper presents a simulation environment for experimenting with different city evacuation scenarios. The simulation couples a flood model with a crowd escape model. The developed agent-based crowd model mimics the behavior of pedestrians escaping from dangerous regions towards safe areas. The system is evaluated through a series of experiments, modeling the flooding of an area in St. Petersburg, Russia.

Distributed simulation of city inundation by coupled surface and subsurface porous flow for urban flood decision support system

We present a decision support system for flood early warning and disaster management. It includes the models for data- driven meteorological predictions, for simulation of atmospheric pressure, wind, long sea waves and seiches; a module for optimization of flood barrier gates operation; models for stability assessment of levees and embankments, for simulation of city inundation dynamics and citizens evacuation scenarios. The novelty of this paper is a coupled distributed simulation of surface and subsurface flows that can predict inundation of low-lying inland zones far away from the edge of the flooded area, as observed in St. Petersburg city during the floods. All the models are wrapped as software services in the CLAVIRE platform for urgent computing, which provides workflow management and resource orchestration.

Virtual Dike: multiscale simulation of dike stability

We present a Virtual Dike simulation module developed as a part of a flood Early Warning System (EWS) for the UrbanFlood project. The UrbanFlood EWS is a distributed system that analyzes sensor data received in real-time from flood defenses (dikes, dams, etc.) and simulates dike stability, breaching and flood propagation. The aim of the Virtual Dike module is to develop an advanced multiscale multiphysics simulation laboratory for expert users and numerical model developers. This lab is used to validate simulation models, to plan experiments and to investigate physical processes influencing dike stability and failure. In the first stage of the project, we have studied the structural stability of the Live Dike, a dike protecting a seaport in Groningen, the Netherlands. The four cross-sections of the dike are equipped with sensors of pore pressure and inclination. For each section, 2D simulations of flow through porous media and dike deformations have been performed under tidal water load. Simulation results have been compared with the sensors data in order to calibrate soil properties. Pore pressure, stress dynamics and structural stability of the dike have been analyzed.

A Grid-based Virtual Reactor: Parallel performance and adaptive load balancing

We address the problem of porting parallel distributed applications from static homogeneous cluster environments to dynamic heterogeneous Grid resources. We introduce a generic technique for adaptive load balancing of parallel applications on heterogeneous resources and evaluate it using a case study application: a Virtual Reactor for simulation of plasma chemical vapour deposition. This application has a modular architecture with a number of loosely coupled components suitable for distribution over the Grid. It requires large parameter space exploration that allows using Grid resources for high-throughput computing. The Virtual Reactor contains a number of parallel solvers originally designed for homogeneous computer clusters that needed adaptation to the heterogeneity of the Grid. In this paper we study the performance of one of the parallel solvers, apply the technique developed for adaptive load balancing, evaluate the efficiency of this approach and outline an automated procedure for optimal utilization of heterogeneous Grid resources for high-performance parallel computing.

Russian-Dutch double-degree Master’s programme in computational science in the age of global education

Abstract We present a new double-degree graduate (Master’s) programme developed together by the ITMO University, Russia and University of Amsterdam, The Netherlands. First, we look into the global aspects of integration of different educational systems and list some funding opportunities. Then, we describe our double-degree program curriculum, suggest the timeline of enrollment and studies, and give some examples of student research topics. Finally, we discuss the issues of joint programs with Russia and suggest possible solutions, analyze the results of the first three student intakes and reflect on the lessons learnt, and share our thoughts and experiences that could be of interest to the international community expanding the educational markets to the vast countries like Russia, China or India. The paper is written for education professionals and contains useful information for potential students. This is an extended version of a conference paper ( http://dx.doi.org/10.1016/j.procs.2014.05.130 ) invited to this special issue of the Journal of Computational Science.

Time-frequency methods for structural health monitoring.

Detection of early warning signals for the imminent failure of large and complex engineered structures is a daunting challenge with many open research questions. In this paper we report on novel ways to perform Structural Health Monitoring (SHM) of flood protection systems (levees, earthen dikes and concrete dams) using sensor data. We present a robust data-driven anomaly detection method that combines time-frequency feature extraction, using wavelet analysis and phase shift, with one-sided classification techniques to identify the onset of failure anomalies in real-time sensor measurements. The methodology has been successfully tested at three operational levees. We detected a dam leakage in the retaining dam (Germany) and “strange” behaviour of sensors installed in a Boston levee (UK) and a Rhine levee (Germany).

The User-Level Scheduling of Divisible Load Parallel Applications With Resource Selection and Adaptive Workload Balancing on the Grid

This paper presents a hybrid resource management environment, operating on both application and system levels developed for minimizing the execution time of parallel applications with divisible workload on heterogeneous grid resources. The system is based on the adaptive workload balancing algorithm (AWLB) incorporated into the distributed analysis environment (DIANE) user-level scheduling (ULS) environment. The AWLB ensures optimal workload distribution based on the discovered application requirements and measured resource parameters. The ULS maintains the user-level resource pool, enables resource selection and controls the execution. We present the results of performance comparison of default self-scheduling used in DIANE with AWLB-based scheduling, evaluate dynamic resource pool and resource selection mechanisms, and examine dependencies of application performance on aggregate characteristics of selected resources and application profile.

Multiscale modelling in real-time flood forecasting systems: From sand grain to dike failure and inundation

Abstract Severe events around the globe have highlighted the threat to life, infrastructure and the environment posed by flooding. Flood forecasting systems are a vital component of broader flood risk management activities. These systems are becoming increasingly more sophisticated as their importance in reducing life loss and economic damages is realized. Part of this increase in complexity is focused on the ability to predict and warn of failures in dykes, levees and embankments. A new European ICT project, UrbanFlood for Environmental Services and Climate Change Adaptation, has recently been commissioned and is introduced in this presentation. The primary objective of the Urban Flood project is to develop early warning systems that will monitor flood protection systems in real-time, identify vulnerable locations, model the failure and predict dike collapse and subsequent inundation. In combination with the damage assessment, Urban Flood will serve as an advanced decision support system, mitigating the impact of seasonal and catastrophic floods. Modeling is one of the key tasks in the project. The models will be required to simulate the behavior of the material properties of the layered dikes (sand, clay, peat, grass or concrete cover, metal frame, dam gates, etc.), during extreme hydraulic loading events. In earthen dikes, extra challenge is posed by the non-linear elastic plastic properties of the deformable clay. A realistic simulation of the dike will model the free-surface water dynamics; convective and diffusive transfer of water inside the porous materials; dynamic response of clay to the water pressure; structural mechanics, deformation and actual dike breakdown and flood. The models shall cover a wide range of scales from a sand grain to a flooded city. The time scales will range from seconds (for water penetrating the soil) to hours (for dike collapse dynamics and ocean tides). Eventually, the models will predict the influence of seasonal and global changes on the stability of flood defense systems. Full 3D transient simulation of dike failure with subsequent inundation will require significant computing resources. The project started three months ago, and we will present the plan for developing the modeling cascade for the system. This work is supported by the UrbanFlood European Union project N 248767, theme ICT-2009.6.4