A Bayesian Belief Network to Infer Incentive Mechanisms to Reduce Antibiotic Use in Livestock Production

Efficient policy intervention to reduce antibiotic use in livestock production requires knowledge about the rationale underlying antibiotic usage. Animal health status and management quality are considered the two most important factors that influence farmers’ decision-making concerning antibiotic use. Information on these two factors is therefore crucial in designing incentive mechanisms. In this paper, a Bayesian belief network (BBN) is built to represent the knowledge on how these factors can directly and indirectly determine antibiotic use and the possible impact on economic incentives. Since both factors are not directly observable (i.e. latent), they are inferred from measurable variables (i.e. manifest variables) which are influenced by these factors. Using farm accounting data and registration data on antibiotic use and veterinary services in specialized finisher pig production farms, a confirmatory factor analysis was carried out to construct these factors. The BBN is then parameterized through regression analysis on the constructed factors and manifest variables. Using the BBN, possible incentive mechanisms through prices and management training are discussed.Livestock Production/Industries,

Stochastic hydro-economic model for groundwater quality management using Bayesian networks

A strong normative development in Europe, including the Nitrate Directive (1991) and the Water Framework Directive (WFD) (2000), has been promulgated. The WFD states that all water bodies have to reach a good quantitative and chemical status by 2015. It is necessary to consider different objectives, often in conflict, for tackling a suitable assessment of the impacts generated by water policies aimed to reduce nitrate pollution in groundwater. For that, an annual lumped probabilistic model based on Bayesian networks (BNs) has been designed for hydro-economic modelling of groundwater quality control under uncertain conditions. The information introduced in the BN model comes from different sources such as previous groundwater flow and mass transport simulations, hydro-economic models, stakeholders and expert opinion, etc. The methodology was applied to the El Salobral-Los Llanos aquifer unit within the 'Easter Mancha' groundwater body, which is one of the largest aquifers in Spain (7,400 km(2)), included in the Júcar River Basin. Over the past 30 years, socioeconomic development within the region has been mainly depending on intensive use of groundwater resources for irrigating crops. This has provoked a continuous groundwater level fall in the last two decades and significant streamflow depletion in the connected Júcar River. This BN model has proved to be a robust Decision Support System for helping water managers in the decision making process.The authors gratefully acknowledge the contributions of the following people and organizations. The study has been partially supported by the European Community 7th Framework Project GENESIS (226536) on groundwater systems and from the subprogram Juan de la Cierva (2010, 2011) of the Spanish Ministry of Science and Innovation as well as from the Plan Nacional I + D + i 2008-2011 of the Spanish Ministry of Science and Innovation (subprojects CGL2009-13238-C02-01 and CGL2009-13238-C02-02). Finally, thanks to the Jucar River Basin Authority (CHJ), IDR of Univ. of Castilla-La Mancha, the Junta Central de Regantes de la Mancha Oriental, and all the different stakeholders who have collaborated on the data and information provided in this research.Molina, J.; Pulido-Velazquez, M.; Llopis Albert, C.; Peña Haro, S. (2013). Stochastic hydro-economic model for groundwater quality management using Bayesian networks. Water Science and Technology. 67(3):579-586. https://doi.org/10.2166/wst.2012.598S57958667

A Bayesian Belief Network to Infer Incentive Mechanisms to Reduce Antibiotic Use in Livestock Production

Efficient policy intervention to reduce antibiotic use in livestock production requires knowledge about the rationale underlying antibiotic usage. Animal health status and management quality are considered the two most important factors that influence farmersâ¿¿ decision-making concerning antibiotic use. Information on these two factors is therefore crucial in designing incentive mechanisms. In this paper, a Bayesian belief network (BBN) is built to represent the knowledge on how these factors can directly and indirectly determine antibiotic use and the possible impact on economic incentives. Since both factors are not directly observable (i.e. latent), they are inferred from measurable variables (i.e. manifest variables) which are influenced by these factors. Using farm accounting data and registration data on antibiotic use and veterinary services in specialized finisher pig production farms, a confirmatory factor analysis was carried out to construct these factors. The BBN is then parameterized through regression analysis on the constructed factors and manifest variables. Using the BBN, possible incentive mechanisms through prices and management training are discusse

Monthly Forecasting of Water Quality Parameters within Bayesian Networks: A Case Study of Honolulu, Pacific Ocean

This study investigates the efficiency of Bayesian network (BN) and also artificial neural network models for predicting water quality parameters in Honolulu, Pacific Ocean. Monthly forecasting of three important characteristics of water body including water temperature, salinity and dissolved oxygen have been taken under consideration. Two separate strategies were applied in which the first strategy was related to prediction of the water quality parameters based on previous time series of the same variable. In the second strategy, an attempt was made to forecast DO using different affecting parameters such as temperature, salinity, previous time series of DO, and amount of chlorophyll. The efficiency of the models were assessed by using error measures. Results revealed that the BN models are superior over the ANN models in case of temperature and DO forecasting. Also, it was found that the first strategy is more efficient than the second strategy for predicting DO concentration. The best BN models for temperature, salinity and DO were achieved when time series of the same parameter up to 3, 2, and 3 previous months applied as input variables respectively. Overall, it can be concluded that BN and ANN models can be successfully applied for water quality modelling and forecasting in coastal waters. Moreover, the current study demonstrated that the BN models have a great ability dealing with time series including incomplete or missing data

A DSS generator for multiobjective optimisation of spreadsheet-based models

Copyright © 2011 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Environmental Modelling & Software. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Environmental Modelling & Software Vol. 26 (2011), DOI: 10.1016/j.envsoft.2010.11.004Water management practice has benefited from the development of model-driven Decision Support Systems (DSS), and in particular those that combine simulation with single or multiple-objective optimisation tools. However, there are many performance, acceptance and adoption problems with these decision support tools caused mainly by misunderstandings between the communities of system developers and users. This paper presents a general-purpose decision-support system generator, GANetXL, for developing specific applications that require multiobjective optimisation of spreadsheet-based models. The system is developed as an Excel add-in that provides easy access to evolutionary multiobjective optimisation algorithms to non-specialists by incorporating an intuitive interactive graphical user interface that allows easy creation of specific decision-support applications. GANetXL’s utility is demonstrated on two examples from water engineering practice, a simple water supply reservoir operation model with two objectives and a large combinatorial optimisation problem of pump scheduling in water distribution systems. The two examples show how GANetXL goes a long way toward closing the gap between the achievements in optimisation technology and the successful use of DSS in practice.Engineering and Physical Sciences Research Council (EPSRC

A novel causal structure-based framework for comparing a basin-wide water–energy–food–ecology nexus applied to the data-limited Amu Darya and Syr Darya river basins

The previous comparative studies on watersheds were mostly based on the comparison of dispersive characteristics, which lacked systemicity and causality. We proposed a causal structure-based framework for basin comparison based on the Bayesian network (BN) and focus on the basin-scale water–energy–food–ecology (WEFE) nexus. We applied it to the Syr Darya River basin (SDB) and the Amu Darya River basin (ADB), of which poor water management caused the Aral Sea disaster. The causality of the nexus was effectively compared and universality of this framework was discussed. In terms of changes in the nexus, the sensitive factor for the water supplied to the Aral Sea changed from the agricultural development during the Soviet Union period to the disputes in the WEFE nexus after the disintegration. The water–energy contradiction of the SDB is more severe than that of the ADB, partly due to the higher upstream reservoir interception capacity. It further made management of the winter surplus water downstream of the SDB more controversial. Due to this, the water–food–ecology conflict between downstream countries may escalate and turn into a long-term chronic problem. Reducing water inflow to depressions and improving the planting structure prove beneficial to the Aral Sea ecology, and this effect of the SDB is more significant. The construction of reservoirs on the Panj River of the upstream ADB should be cautious to avoid an intense water–energy conflict such as the SDB's. It is also necessary to promote the water-saving drip irrigation and to strengthen the cooperation

Assessing the role of economic instruments in a policy mix for biodiversity conservation and ecosystem services provision: a review of some methodological challenges

In this paper we review a number of methodological challenges of evaluating and designing economic instruments aimed at biodiversity conservation and ecosystem services provision in the context of an existing policy mix. In the context of the EU 2010 goal of halting biodiversity loss, researchers have been called upon to evaluate the role of economic instruments for cost-effective decision-making, as well as non-market methods to assess their benefits. We argue that cost-effectiveness analysis (CEA) and non-market valuation (NMV) methods are necessary, but not sufficient, approaches to assessing the role of economic instruments in a policy mix. We review the principles of “social-ecological-systems”(SES) (Ostrom et al. 2007) and discuss how SES can complement economic cost and benefit assessment methods, in particular in policy design research. To illustrate our conceptual comparison of assessment methodologies, we look at two examples of economic instruments at different government levels – payments for ecosystem services (PES) at farm level and ecological fiscal transfers to municipal /county government. What conceptual problems are introduced when evaluating policies in an instrument mix? How can the SES framework complement CEA and NMV in policy assessment and design? We draw on experiences from Brazil and Costa Rica to exemplify these questions. We conclude with some research questions

Role of irrigation water pricing in sustainable water resources management along the Tarim river, Northwest China

Das Hauptaugenmerk dieser Dissertation war auf die Frage gerichtet, ob Wasserpreise in der Bewässerungslandwirtschaft entlang des Tarims zu einer effizienteren Wassernutzung führen können. Um die aktuellen und historischen Entwicklungen hinsichtlich der Land- und Wassernutzung und deren treibenden Kräfte im Aksu-Tarimbecken zu identifizieren, wurde ein Workshop in Urumqi, der Hauptstadt der Autonomen Uigurischen Provinz Xinjiang, durchgeführt. Teilnehmer waren lokale Experten verschiedener Forschungsdisziplinen sowie weitere relevante Akteure, beispielsweise politische Entscheidungsträger. Ergänzend wurden Sekundärdaten aus statistischen Jahrbüchern und offiziellen politischen Dokumenten erhoben. Ergebnisse zeigten, wie im ersten Artikel dargestellt, dass im Zeitraum von 1989 bis 2011 eine enorme Expansion landwirtschaftlicher Nutzflächen und damit ein stark erhöhter Wasserverbrauch stattgefunden hat. Es konnte gezeigt werden, dass diese Entwicklung durch eine Kombination der folgenden Faktoren bedingt wurde: (a) starkes Bevölkerungswachstum, erhöhte Erzeugerpreise, (c) gesteigerte landwirtschaftliche Produktivität, (d) das Regierungsprogramm zur Aufforstung (Grain for Green) und (e) mangelhafte Kontrolle der Expansion landwirtschaftlicher Flächen. Die Reaktionen von Landwirten auf veränderte Wasserpreise ist ein entscheidender Faktor bei der Bestimmung von effizienten Wasserpreisen zur Einsparung und Nachfragereduzierung der knappen Ressource. Von Juli bis August 2012 wurde in verschiedenen Regionen entlang des Tarims eine Farm-Haushaltsbefragung mit insgesamt 257 Interviews durchgeführt. 128 dieser Interviews dienten der Analyse der Reaktionen von Landwirten auf erhöhte Wasserpreise. Die Ergebnisse dieser Analysen sind im zweiten Artikel beschrieben. Es konnte gezeigt werden, dass lediglich die Hälfte der befragten Betriebe ihre Bewässerungsmethoden zu Gunsten einer effizienteren Wassernutzung anpassen würden. Viele Landwirte kündigten hingegen an, dass sie einem erhöhten Preisdruck mit einer vermehrten Grundwassernutzung entgegenwirken würden, was jedoch schwerwiegende ökologische Folgen haben kann. Auf Grund des Umfangs und der Komplexität des Themas, war es bei der direkten Befragung der Landwirte nicht möglich, die Reaktionen auf verschiedene Preisniveaus zu ermitteln. Zudem müssen institutionelle Aspekte bei einer umfassenden Wasserpreisreform berücksichtigt werden. Aus diesem Grund wurde im dritten Artikel der Einfluss verschiedener Wasserpreise, verschiedener Praktiken der Gebührenerhebung, sowie weiterer agrarpolitischer Maßnahmen auf die Wassernutzungseffizienz mittels Bayesschen Netzwerken modelliert. Bei um 0-50% erhöhten Wasserpreisen konnte kein signifikanter Einfluss auf die Wassernutzungseffizienz nachgewiesen werden. Lediglich eine Verdopplung der aktuellen Wasserpreise hatte einen nachweisbar positiven Effekt auf die Wassernutzungseffizienz unter der Voraussetzung einer verbrauchsorientierten Preisermittlung (=volumetrischer Wasserpreis). Das entwickelte Modell konnte zudem zeigen, dass volumetrische Wasserpreise, kombiniert mit der Förderung effizienter Bewässerungstechnologie und landwirtschaftlicher Beratung die Möglichkeit bieten, die Wassernutzungseffizienz zu erhöhen. Im vierten Artikel wurde die Wirtschaftlichkeit des Baumwollanbaus und der Landnutzungsänderungen entlang des Tarims im Zeitraum von 1989 bis 2009 analysiert. Hierfür wurden Sekundärdaten aus statistischen Jahrbüchern verwendet. Die Ergebnisse einer durchgeführten Trendanalyse zeigen eine Expansion des Baumwollanbaus während sich die Fläche alternativer Nutzpflanzen in geringem Umfang verringerte. Außerdem konnte im Baumwollanbau am Oberlauf des Tarims eine höhere Produktivität als flussabwärts nachgewiesen werden. Landwirte der Militärfarmen des Xinjiang Production and Construction Corps waren hierbei effizienter als Landwirte außerhalb der Militärfarmen. Aus den Ergebnissen der einzelnen Artikel kann gefolgert werden, dass Wasserpreise als alleinige Maßnahme zur Erhöhung der Wassernutzungseffizient entlang des Tarims nicht genügen. Für die erfolgreiche Implementierung eines effizienteren Wassermanagements sind zusätzliche Anpassungen der Preismechanismen, sowie gezielte agrarpolitische Maßnahmen notwendig. Volumetrische Wasserpreise, Subventionen effizienter Bewässerungstechnologien, landwirtschaftliche Beratung sowie grundlegende institutionelle Reformen erscheinen unausweichlich, um eine nachhaltigere Wassernutzung in der Studienregion zu ermöglichen. Ein besonderes Augenmerk sollte auf der Nutzung der knappen Grundwasservorräte liegen, insbesondere bei erhöhten Wasserpreisen. Zusätzlicher Forschungsbedarf besteht bei den Auswirkungen von Wasserpreisen auf das landwirtschaftliche Betriebseinkommen, der Übertragbarkeit von Wassernutzungsrechten und bei der Rolle von Vereinigungen und Genossenschaften von Wassernutzern bezüglich einer effizienteren Wassernutzung entlang des Tarims.The main objectives of the study are to explore whether irrigation water pricing can lead to efficient water use in agriculture along the Tarim River. To understand land and water use development and driving forces along the Aksu-Tarim Basin, a workshop was conducted in Urumqi which is capital city of Xinjiang Uyghur Autonomous Region. Local experts from different research disciplines as well as relevant stakeholder participated in the workshop. Besides, data were collected and analyzed from preselected sources such as statistical yearbook and governments official document. Research results embedded in the first article revealed that there was a huge land expansion and increase in water use for agriculture during the period from 1989 to 2011. The results also indicate that interaction of vast population growth, positive price development, agricultural profitability increase, governments afforestation program (Grain for Green) and insufficient control of land expansion were the main driving forces for those developments. Farmers behavior towards the changes of irrigation water pricing is one of the important factor determining efficiency of water pricing to elicit water conservation and demand reduction. Therefore, a total of 257 farm household interviews were conducted, of which 128 served to find out farmers responses towards the changes of water pricing in different parts of Tarim River in July and August 2012. The results of statistical analyses are presented in the second article. Results show that only less than half of the interviewed farm households would react to increased water prices with proper changes of their farming practices leading to a more efficient water use. Results also show that increasing water prices encourage the farmers to shift their irrigation from surface water to groundwater which may result in further environmental problems. In the second article it is not possible to access the impact of different water price levels and changes in the water pricing practices because of its technicality and complexity. Besides, an irrigation water pricing reform needs to consider institutional aspects which are usually ignored in research on water pricing. Therefore, an innovative approach, Bayesian network modeling, was employed to find out the effects of different water price levels, changes in water pricing practices, and other agricultural policy options on the water use efficiency along the Tarim River. Results presented in the third article show no significant impact of water prices increased by 0-50% on water use efficiency. Solely an increase of 100% may have a relevant positive effect on water use efficiency. The model results also reveal that water pricing may provide a promising option to increase water use efficiency provided that volumetrically measuring systems, subsidies for water saving technologies, and technical support are available. The fourth article discusses the economics of cotton production and land use changes along the Tarim River from 1989 to 2009 using data from official statistical yearbooks. The results of a trend analysis indicate that the land area of cotton increased. In contrast, the area of other crops slightly decreased. Results of comparative advantage index of cotton production show that most farmers in the upper stream are more efficient in cotton production compared to farmers of the lower stream, whereas farmers in Xinjiang Production and Construction Corps are more efficient than farmers outside the Xinjiang Production and Construction Corps. The overall results of the study indicate that irrigation water pricing is not the best option to achieve an efficient water use in agriculture along the Tarim River. It requires additional adjustments and supportive agricultural policies such as the availability of volumetric measuring systems, subsidies for water-saving technologies, technological support for farmers, as well as a further institutional reform. Besides, special attention should be given to the protection of groundwater resources, especially when water prices increase. Furthermore, additional research is needed to examine the impacts of water pricing on farmers welfare, and the role of transferable water rights and water user associations in terms of an efficient water use along the Tarim River

Assessment and implementation of evolutionary algorithms for optimal management rules design in water resources systems

Tesis por compendioWater is an essential resource from an environmental, biological, economic or social point of view. In basin management, the irregular distribution in time and in space of this resource is well known. This issue is worsened by extreme climate conditions, generating drought periods or flood events. For both situations, optimal management is necessary. In one case, different water uses should be supplied efficiently using the available surface and groundwater resources. In another case, the most important goal is to avoid damages in flood areas, including the loss of human lives, but also to optimize the revenue of energy production in hydropower plants, or in other uses. The approach presented in this thesis proposes to obtain optimal management rules in water resource systems. With this aim, evolutionary algorithms were combined with simulation models. The first ones, as optimization tools, are responsible for guiding the process iterations. In each iteration, a new management rule is defined in the simulation model, which is computed to comprehend the situation of the system after applying this new management. For testing the proposed methodology, four evolutionary algorithms were assessed combining them with two simulation models. The methodology was implemented in four real case studies. This thesis is presented as a compendium of five manuscripts: three scientific papers published in journals (which are indexed in the Journal Citation Report), another under review, and the last manuscript from Conference Proceedings. In the first manuscript, the Pikaia optimization algorithm was combined with the network flow SIMGES simulation model for obtaining four different types of optimal management rules in the Júcar River Basin. In addition, the parameters of the Pikaia algorithm were also analyzed to identify the best combination of them to use in the optimization process. In the second scientific paper, the multi-objective NSGA-II algorithm was assessed to obtain a parametric management rule in the Mijares River basin. In this case, the same simulation model was linked with the evolutionary algorithm. In the Conference manuscript, an in-depth analysis of the Tirso-Flumendosa-Campidano (TFM) system using different scenarios and comparing three water simulation models for water resources management was developed. The third published manuscript presented the assessment and comparison of two evolutionary algorithms for obtaining optimal rules in the TFM system using SIMGES model. The algorithms assessed were the SCE-UA and the Scatter Search. In this research paper, the parameters of both algorithms were also analyzed as it was done with the Pikaia algorithm. The management rules in the three first manuscripts were focused to avoid or minimize deficits in urban and agrarian demands and, in some case studies, also to minimize the water pumped. Finally, in the last document, two of the algorithms used in previous manuscripts were assessed, the mono-objective SCE-UA and the multi-objective NSGA-II. For this research, the algorithms were combined with RS MINERVE software to manage flood events in Visp River basin minimizing damages in risk areas and losses in hydropower plants. Results reached in the five manuscripts demonstrate the validity of the approach. In all the case studies and with the different evolutionary algorithms assessed, the obtained management rules achieved a better system management than the base scenario of each case. These results usually mean a decrease of the economic costs in the management of water resources. However, comparing the four algorithms assessed, SCE-UA algorithm proved to be the most efficient due to the different stop/convergence criteria and its formulation. Nevertheless, NSGA-II is the most recommended due to its multi-objective search focus on the enhancement of different objectives with the same importance where the decision makers can make the best decision for the management of the system.El agua es un recurso esencial desde el punto de vista ambiental, biológico, económico o social. En la gestión de cuencas, es bien conocido que la distribución del recurso en el tiempo y el espacio es irregular. Este problema se agrava debido a condiciones climáticas extremas, generando períodos de sequía o inundaciones. Para ambas situaciones, una gestión óptima es necesaria. En un caso, el suministro de agua a los diferentes usos del sistema debe realizarte eficientemente empleando los recursos disponibles, tanto superficiales como subterráneos. En el otro caso, el objetivo más importante es evitar daños en las zonas de inundación, incluyendo la pérdida de vidas humanas, pero al mismo tiempo, optimizar los beneficios de centrales hidroeléctricas, o de otros usos. El enfoque presentado en esta tesis propone la obtención de reglas de gestión óptimas en sistemas reales de recursos hídricos. Con este objetivo, se combinaron algoritmos evolutivos con modelos de simulación. Los primeros, como herramientas de optimización, encargados de guiar las iteraciones del proceso. En cada iteración se define una nueva regla de gestión en el modelo de simulación, que se evalúa para conocer la situación del sistema después de aplicar esta nueva gestión. Para probar la metodología propuesta, se evaluaron cuatro algoritmos evolutivos combinándolos con dos modelos de simulación. La metodología se implementó en cuatro casos de estudio reales. Esta tesis se presenta como un compendio de cinco publicaciones: tres de ellas en revistas indexadas en el Journal Citation Report, otra en revisión y la última como publicación de un congreso. En el primer manuscrito, el algoritmo de optimización Pikaia se combinó con el modelo de simulación SIMGES para obtener reglas de gestión óptimas en la cuenca del río Júcar. Además, se analizaron los parámetros del algoritmo para identificar la mejor combinación de los mismos en el proceso de optimización. El segundo artículo evaluó el algoritmo multi-objetivo NSGA-II para obtener una regla de gestión paramétrica en la cuenca del río Mijares. En el trabajo presentado en el congreso se desarrolló un análisis en profundidad del sistema Tirso-Flumendosa-Campidano utilizando diferentes escenarios y comparando tres modelos de simulación para la gestión de los recursos hídricos. En el tercer manuscrito publicado se evaluó y comparó dos algoritmos evolutivos (SCE-UA y Scatter Search) para obtener reglas de gestión óptimas en el sistema Tirso-Flumendosa-Campidano. En dicha investigación también se analizaron los parámetros de ambos algoritmos. Las reglas de gestión de estas cuatro publicaciones se enfocaron en evitar o minimizar los déficits de las demandas urbanas y agrarias y, en ciertos casos, también en minimizar el caudal bombeado, utilizando para ello el modelo de simulación SIMGES. Finalmente, en la última publicación se evaluó el algoritmo mono-objetivo SCE-UA y el multi-objetivo NSGA-II. Para esta investigación, los algoritmos se combinaron con el software RS MINERVE para gestionar los eventos de inundación en la cuenca del río Visp minimizando los daños en las zonas de riesgo y las pérdidas en las centrales hidroeléctricas. Los resultados obtenidos en las cinco publicaciones demuestran la validez del enfoque. En todos los casos de estudio y, con los diferentes algoritmos evolutivos evaluados, las reglas de gestión obtenidas lograron una mejor gestión del sistema que el escenario base de cada caso. Estos resultados suelen representar una disminución de los costes económicos en la gestión de los recursos hídricos. Comparando los cuatro algoritmos, el SCE-UA demostró ser el más eficiente debido a los diferentes criterios de convergencia. No obstante, el NSGA-II es el más recomendado debido a su búsqueda multi-objetivo enfocada en la mejora, con la misma importancia, de diferentes objetivos, donde los tomadores de decisiones pueden selL'aigua és un recurs essencial des del punt de vista ambiental, biològic, econòmic o social. En la gestió de conques, és ben conegut que la distribució del recurs en el temps i l'espai és irregular. Este problema s'agreuja a causa de condicions climàtiques extremes, generant períodes de sequera o inundacions. Per a ambdúes situacions, una gestió òptima és necessària. En un cas, el subministrament d'aigua als diferents usos del sistema ha de realitzar-se eficientment utilitzant els recursos disponibles, tant superficials com subterranis. En l'altre cas, l'objectiu més important és evitar danys en les zones d'inundació, incloent la pèrdua de vides humanes, però al mateix temps, optimitzar els beneficis de centrals hidroelèctriques, o d'altres usos. La proposta d'esta tesi és l'obtenció de regles de gestió òptimes en sistemes reals de recursos hídrics. Amb este objectiu, es van combinar algoritmes evolutius amb models de simulació. Els primers, com a ferramentes d'optimització, encarregats de guiar les iteracions del procés. En cada iteració es definix una nova regla de gestió en el model de simulació, que s'avalua per a conéixer la situació del sistema després d'aplicar esta nova gestió. Per a provar la metodologia proposada, es van avaluar quatre algoritmes evolutius combinant-los amb dos models de simulació. La metodologia es va implementar en quatre casos d'estudi reals. Esta tesi es presenta com un compendi de cinc publicacions: tres d'elles en revistes indexades en el Journal Citation Report, una altra en revisió i l'última com a publicació d'un congrés. En el primer manuscrit, l'algoritme d'optimització Pikaia es va combinar amb el model de simulació SIMGES per a obtindre regles de gestió òptimes en la conca del riu Xúquer. A més, es van analitzar els paràmetres de l'algoritme per a identificar la millor combinació dels mateixos en el procés d'optimització. El segon article va avaluar l'algoritme multi-objectiu NSGA-II per a obtindre una regla de gestió paramètrica en la conca del riu Millars. En el treball presentat en el congrés es va desenvolupar una anàlisi en profunditat del sistema Tirso-Flumendosa-Campidano utilitzant diferents escenaris i comparant tres models de simulació per a la gestió dels recursos hídrics. En el tercer manuscrit publicat es va avaluar i va comparar dos algoritmes evolutius (SCE-UA i Scatter Search) per a obtindre regles de gestió òptimes en el sistema Tirso-Flumendosa-Campidano. En dita investigació també es van analitzar els paràmetres d'ambdós algoritmes. Les regles de gestió d'estes quatre publicacions es van enfocar a evitar o minimitzar els dèficits de les demandes urbanes i agràries i, en certs casos, també a minimitzar el cabal bombejat, utilitzant per a això el model de simulació SIMGES. Finalment, en l'última publicació es va avaluar l'algoritme mono-objectiu SCE-UA i el multi-objetiu NSGA-II. Per a esta investigació, els algoritmes es van combinar amb el programa RS MINERVE per a gestionar els esdeveniments d'inundació en la conca del riu Visp minimitzant els danys en les zones de risc i les pèrdues en les centrals hidroelèctriques. Els resultats obtinguts en les cinc publicacions demostren la validesa de la metodología. En tots els casos d'estudi i, amb els diferents algoritmes evolutius avaluats, les regles de gestió obtingudes van aconseguir una millor gestió del sistema que l'escenari base de cada cas. Estos resultats solen representar una disminució dels costos econòmics en la gestió dels recursos hídrics. Comparant els quatre algoritmes, el SCE-UA va demostrar ser el més eficient a causa dels diferents criteris de convergència. No obstant això, el NSGA-II és el més recomanat a causa de la seua cerca multi-objectiu enfocada en la millora, amb la mateixa importància, de diferents objectius, on els decisors poden seleccionar la millor opció per a la gestió del sistema.Lerma Elvira, N. (2017). Assessment and implementation of evolutionary algorithms for optimal management rules design in water resources systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90547TESISCompendi