A dimensionality reduction approach for many-objective Markov Decision Processes: Application to a water reservoir operation problem

The operation of complex environmental systems usually accounts for multiple, conflicting objectives, whose presence imposes to explicitly consider the preference structure of the parties involved. Multiobjective Markov Decision Processes are a useful mathematical framework for the resolution of such sequential, decision-making problems. However, the computational requirements of the available optimization techniques limit their application to problems involving few objectives. In real-world applications it is therefore common practice to select few, representative objectives with respect to which the problem is solved. This paper proposes a dimensionality reduction approach, based on the Non-negative Principal Component Analysis (NPCA), to aggregate the original objectives into a reduced number of principal components, with respect to which the optimization problem is solved. The approach is evaluated on the daily operation of a multi-purpose water reservoir (Tono Dam, Japan) with 10 operating objectives, and compared against a 5-objectives formulation of the same problem. Results show that the NPCA-based approach provides a better representation of the Pareto front, especially in terms of consistency and solution diversity

Verbano

L’obiettivo del progetto è la soluzione del problema Verbano tramite la scelta di una nuova regolazione e di oppurtuni interventi strutturali. Tale soluzione deve tendere a minimizzare i danni causati da eventi alluvionali tanto a monte quanto a valle, i danni indotti dalla mancata fornitura idrica agli utenti irrigui ed idroelettrici di valle e quelli subiti dalla navigazione e dal turismo quando si deprimono eccessivamente i livelli lacuali, senza trascurare, nel contempo, il mantenimento di un deflusso minimo nel Ticino, a valle dello sbarramento del Panperduto. In tale ricerca si dovranno ovviamente tener conto dei vincoli posti dalla capacità di smaltimento delle portate all’incile del lago e dalla necessità di mantenere attiva la sua naturale funzione di laminazione in occasione di eventi alluvionali che interessino anche il Po

Accounting for river morphology in the management of red river (vietnam): a numerical modeling approach

During last 15 years, the Red River in northern VietNam has experienced severe river bed degradation along its lower course. The continued decrease of the minimum water levels aggravated water scarcity for agriculture. These outcomes can be attributed to strong in stream sediment mining, major upstream impoundments, climatic and land use changes. The aim of this work is to provide a valuable tool to assess the effects of different reservoir water releases and sediment mining policies on river reach morphology. A 1D mobile bed finite volume numerical model has been set up and preliminary results on the recent 2000-2009 period are presented and discussed. The model features facilitate its integration in optimization algorithms devoted to water management strategies

Universal Approximators for Direct Policy Search in Multi-Purpose Water Reservoir Management: A Comparative Analysis

open5This study presents a novel approach which combines direct policy search and multi-objective evolutionary algorithms to solve high-dimensional state and control space water resources problems involving multiple, conflicting, and non-commensurable objectives. In such a multi-objective context, the use of universal function approximators is generally suggested to provide flexibility to the shape of the control policy. In this paper, we comparatively analyze Artificial Neural Networks (ANN) and Radial Basis Functions (RBF) under different sets of input to estimate their scalability to high-dimensional state space problems. The multi-purpose HoaBinh water reservoir in Vietnam, accounting for hydropower production and flood control, is used as a case study. Results show that the RBF policy parametrization is more effective than the ANN one. In particular, the approximated Pareto front obtained with RBF control policies successfully explores the full tradeoff space between the two conflicting objectives, while the ANN solutions are often Pareto-dominated by the RBF ones.Matteo Giuliani; Emanuele Mason; Andrea Castelletti; Francesca Pianosi; Rodolfo Soncini SessaGiuliani, Matteo; Mason, Emanuele; Castelletti, ANDREA FRANCESCO; Pianosi, Francesca; SONCINI SESSA, Rodolf

PIP: a participatory and integrated planning procedurefor decision making in water resource systems

Abstract: There is a wide consensus that integrated planning and management (iwrm) plays a crucial role in the current context of water resources, as well as that any water related decisional process must be participated in order to reach transparent and readily acceptable decisions. At European level the iwrm paradigm has been adopted by the Water Framework Directive that came into force in December 2000. The directive sets out a detailed framework for the improved planning and management of water, including in particular the development of River Basin Management Plans (rbmp). Though the wfd political objectives are clear and well stated, as well as the general principles to be followed in the rbmp implementation, a gap exists between concept and practice, between what to reach through the plans and how to reach it, which even reflects in the lack of communication between scientists and policy-makers. This might be partially imputable to the poor attention devoted to the planning and managing issues in the early phase of the wfd implementation: of many projects (Harmoni-ca, CatchMod cluster and merit) promoted by the eu within the Five Program Framework (fp5