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The differential evolution (DE) algorithm is a powerful search technique for solving global optimization problems over continuous space. The search initialization for this algorithm is handled stochastically and therefore does not adequately capture vague preliminary knowledge. This paper proposes a novel Fuzzy Differential Evolution (FDE) algorithm, as an alternative approach, where the vague information on the search space can be represented and used to deliver a more focused search. The proposed FDE algorithm utilizes (a) fuzzy numbers to represent vague knowledge and (b) random alpha-cut levels for the search initialization. The alpha-cut intervals created during the initialization are used for fuzzy interval based mutation in successive search iterations. Four benchmark functions are used to demonstrate performance of the new FDE and its practical value. Additionally, the application of the FDE algorithm is illustrated through a reservoir operation case study problem. The new algorithm shows faster convergence in most of these functions. [ABSTRACT FROM AUTHOR]

A preprocessing program for a distributed hydrological model is very important because it will greatly influence the results of runoff simulation. Runoff simulations include several procedures, such as the determination of flow directions, definition of runoff routing orders, estimation of flow accumulation areas and extraction of drainage networks, etc. In order to simplify the development work and to improve the efficiency of model development, a preprocessing program was developed that can work independently with a graphic user interface. Only digital elevation model (DEM) data are required in this program and characteristics of the program include the following components: (1) a method for the determination of flow direction without sink filling; (2) a leaf clipping method for watershed partitioning; and (3) the determination of the order of runoff routing according to a topdown method. Finally, a case study in the Lhasa River basin is presented, and three case studies in the Wei River, Zhangweinan River and Sanchuan River basins are selected to validate the program. The results show that disconnected or parallel drainage networks can be avoided by using the preprocessing program, especially in flat areas, which can significantly improve the development of distributed hydrological models. [ABSTRACT FROM AUTHOR]

The present paper reviews several approaches that can be used in capturing urban features in coarse resolution two-dimensional (2D) models and it demonstrates the effectiveness of a new approach against the straightforward 2D modelling approach on a hypothetical and a real-life case study work. The case study work addresses the use of coarse grid resolutions in 2D non-inertia models. The 2D noninertia model used solves continuity andmomentumequations over the cells of the coarse model while taking the minimum elevation as a surface level. The volume stored in every cell is calculated as a volume-depth relationship. In order to replicate restriction in conveyances in x-y directions of fine resolution models due to building blocks, the friction values of the coarse-resolution model are adjusted to match the results of the high-resolution model. The work presented in this paper shows the possibility of applying a 2D non-inertia model more effectively in urban flood modelling applications whilst still making use of the high resolution of topographic data that can nowadays be easily acquired. [ABSTRACT FROM AUTHOR]

The paper is focused on analyzing the public-private partnerships (PPP) in the water sector in Romania. A methodology based on the system lifecycle approach of ISO/IEC 15288:2008 is proposed to study the challenges in designing and implementing this type of policy instrument. The authors use structured approaches for investigating key issues related to PPP projects and they also illustrate the application potential of the concept by comparing two categories of projects, through a case study. One of the studied project categories refers to successful implementations of PPP, whilst the other refers to failures, thus showcasing the power of abstractization of systems engineering in understanding the real issues involved in these undertakings and allowing for improvement opportunities to be discovered. [ABSTRACT FROM AUTHOR]

This paper describes an Application Programming Interface (API) for managing multi-dimensional data produced for water resource computational modeling that is being developed by the US Army Engineer Research and Development Center (ERDC), in conjunction with Brigham Young University. This API, along with a corresponding data standard, is being implemented within ERDC computational models to facilitate rapid data access, enhanced data compression and data sharing, and cross-platform independence. The API and data standard are known as the extensible Model Data Format (XMDF), and version 1.3 is available for free download. This API is designed to manage geometric data associated with grids, meshes, riverine and coastal cross sections, and both static and transient array-based datasets. The inclusion of coordinate system data makes it possible to share data between models developed in different coordinate systems. XMDF is used to store the data-intensive components of a modeling study in a compressed binary format that is platform independent. It also provides a standardized file format that enhances modeling linking and data sharing between models. [ABSTRACT FROM AUTHOR]

In this paper, data from 105 soil and groundwater remediation projects at BP gasoline service stations located in the state of Illinois were mined for lessons to reduce cost and improve management of remediation sites. Data mining software called D2K was used to train decision tree, stepwise linear regression and instance-based weighting models that relate hydrogeologic, sociopolitical, temporal and remedial factors in the site closure reports to remediation cost. The most important factors influencing cost were found to be the amount of soil excavated and the number of groundwater monitoring wells installed, suggesting that better management of excavation and well placement could result in significant cost savings. The best model for predicting cost classes (low, medium and high cost) was the decision tree, which had a prediction accuracy of approximately 73%. The misclassification of approximately 27% of the sites by even the best model suggests that remediation costs at service stations are influenced by other site-specific factors that may be difficult to accurately predict in advance. [ABSTRACT FROM AUTHOR]