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One of the best known hydraulic water distribution modeling toolkits that is most used by both researchers and practitioners is EPANET 2. Initially the authors aimed to speed up such simulations by utilizing modern multicore processors in the code implementation. The 30-year-old linear solver was replaced in steps by seven different modern multicore capable solvers. Subsequently, speedup tests were carried out with small- (up to 1.6 x 10³ nodes), medium- (up to 6.3 x 104 nodes) and large-sized (up to 6.3 x 105 nodes) test cases. None of the tested solvers was found to perform faster than the original solver for networks with a real-world character, although two solvers showed a speedup on medium and large water distribution networks. This is an example that strategies to reduce computation time can produce promising results in a theoretic research environment, but fail in practical engineering applications. Likewise, this paper highlights again the importance of considering realistic test cases during the implementation phase. Further, the authors point out why the different tested strategies in this work have not succeeded. Although two other issues (implemented hash table and node reordering) could be identified for potential improvement of the code, it was concluded that the original solver is still the fastest for practical system configurations. [ABSTRACT FROM AUTHOR]

The aim of this work is to analyze the extent to which the demand-related uncertainty and long-term effects impact the optimization of the operation of a small hydropower system (SHPS). To this end, a SHPS is assumed to be installed in a real Alpine water distribution system, and its settings are optimized in order to investigate the SHPS long time performance (10-year simulations with EPANET 2) under different future scenarios. Results show that neglecting demand uncertainty and the long-term sequence of demand patterns prevents obtaining a realistic assessment of the profits connected with the SHPS operation. Furthermore, the issue of setting optimization is marginal compared to that of uncertainty assessment and long-term effects. [ABSTRACT FROM AUTHOR]

Accounting for water in a distribution system can be improved by dividing systems into smaller, metered zones. This paper proposes an approach that could create boundaries for district metered areas (DMA) automatically on the basis of the community structure of water distribution systems. Community structure-the gathering of vertices into communities such that there is a higher density of edges within communities than between them-is a common property of many complex systems. For verification, the method was tested on a real-world distribution system, and the result was compared with a manually designed DMA layout. Although further improvements are necessary, because the achieved community structure is in excellent agreement with the zoning plan in reality, this approach is a new addition to the number of automated methods aimed at complementing and eventually substituting the empirical trial-and-error approach. [ABSTRACT FROM AUTHOR]

Urban drainage networks are under constant pressure caused by a permanently changing environment. For proactive planning, management, and adaptation of urban water infrastructure, a robust and comprehensive knowledge base is needed as decision support. This paper shows an integrated approach for decision support consisting of urban development modeling, climate projections, hydrodynamic sewer modeling, and Web-GIS visualization of interactive risk maps for pluvial flooding. The application on an Alpine case study demonstrates the benefits of such a combined consideration of different drivers. Climate projections of precipitation are based on four climate projections produced specifically for the Alps on a 0.1° grid. In order to obtain precipitation data with an adequate resolution for urban drainage modeling, the projections are downscaled using a statistical downscaling method. The results indicate a trend toward more intense heavy precipitation during summer until 2050. The effect of this trend can either be compensated or amplified by city development. It is shown that population growth on its own does not necessarily lead to a decrease of system performance, but that clever spatial planning can reduce negative effects. The visualization helps to involve stakeholders, politicians, and the public by illustrating model results for strategic planning and in workshops. [ABSTRACT FROM AUTHOR]