38 research outputs found

    Design of optimal reservoir operating rules in large water resources systems combining stochastic programming, fuzzy logic and expert criteria

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    Given the high degree of development of hydraulic infrastructure in the developed countries, and with the increasing opposition to constructing new facilities in developing countries, the focus of water resource system analysis has turned into defining adequate operation strategies. Better management is necessary to cope with the challenge of supplying increasing demands and conflicts on water allocation while facing climate change impacts. To do so, a large set of mathematical simulation and optimization tools have been developed. However, the real application of these techniques is still limited. One of the main lines of research to fix this issue regards to the involvement of experts' knowledge in the definition of mathematical algorithms. To define operating rules in a way in which system operators could rely, their expert knowledge should be fully accounted and merged with the results from mathematical algorithms. This thesis develops a methodological framework and the required tools to improve the operation of large-scale water resource systems. In such systems, decision-making processes are complex and supported, at least partially, by the expert knowledge of decision-makers. This importance of expert judgment in the operation strategies requires mathematical tools able to embed and combine it with optimization algorithms. The methods and tools developed in this thesis rely on stochastic programming, fuzzy logic and the involvement of system operators during the whole rule-defining process. An extended stochastic programming algorithm, able to be used in large-scale water resource systems including stream-aquifer interactions, has been developed (the CSG-SDDP). The methodological framework proposed uses fuzzy logic to capture the expert knowledge in the definition of optimal operating rules. Once the current decision-making process is fairly reproduced using fuzzy logic and expert knowledge, stochastic programming results are introduced and thus the performance of the rules is improved. The framework proposed in this thesis has been applied to the Jucar river system (Eastern Spain), in which scarce resources are allocated following complex decision-making processes. We present two applications. In the first one, the CSG-SDDP algorithm has been used to define economically-optimal conjunctive use strategies for a joint operation of reservoirs andaquifers. In the second one, we implement a collaborative framework to couple historical records with expert knowledge and criteria to define a decision support system (DSS) for the seasonal operation of the reservoirs of the Jucar River system. The co-developed DSS tool explicitly reproduces the decision-making processes and criteria considered by the system operators. Two fuzzy logic systems have been developed and linked with this purpose, as well as with fuzzy regressions to preview future inflows. The DSS developed was validated against historical records. The developed framework offers managers a simple way to define a priori suitable decisions, as well as to explore the consequences of any of them. The resulting representation has been then combined with the CSG-SDDP algorithm in order to improve the rules following the current decision-making process. Results show that reducing pumping from the Mancha Oriental aquifer would lead to higher systemwide benefits due to increased flows by stream-aquifer interaction. The operating rules developed successfully combined fuzzy logic, expert judgment and stochastic programming, increasing water allocations to the demands by changing the way in which Alarcon, Contreras and Tous are balanced. These rules follow the same decision-making processes currently done in the system, so system operators would feel familiar with them. In addition, they can be contrasted with the current operating rules to determine what operation options can be coherent with the current management and, at the same time, achieve an optimal operationDado el alto número de infraestructuras construidas en los países desarrollados, y con una oposición creciente a la construcción de nuevas infraestructuras en los países en vías de desarrollo, la atención del análisis de sistemas de recursos hídricos ha pasado a la definición de reglas de operación adecuadas. Una gestión más eficiente del recurso hídrico es necesaria para poder afrontar los impactos del cambio climático y de la creciente demanda de agua. Para lograrlo, un amplio abanico de herramientas y modelos matemáticos de optimización se han desarrollado. Sin embargo, su aplicación práctica en la gestión hídrica sigue siendo limitada. Una de las más importantes líneas de investigación para solucionarlo busca la involucración de los expertos en la definición de dichos modelos matemáticos. Para definir reglas de operación en las cuales los gestores confíen, es necesario tener en cuenta su criterio experto y combinarlo con algoritmos de optimización. La presente tesis desarrolla una metodología, y las herramientas necesarias para aplicarla, con el fin de mejorar la operación de sistemas complejos de recursos hídricos. En éstos, los procesos de toma de decisiones son complicados y se sustentan, al menos en parte, en el juicio experto de los gestores. Esta importancia del criterio de experto en las reglas de operación requiere herramientas matemáticas capaces de incorporarlo en su estructura y de unirlo con algoritmos de optimización. Las herramientas y métodos desarrollados se basan en la optimización estocástica, en la lógica difusa y en la involucración de los expertos durante todo el proceso. Un algoritmo estocástico extendido, capaz de ser usado en sistemas complejos con interacciones río-acuífero se ha desarrollado (el CSG-SDDP). La metodología definida usa lógica difusa para capturar el criterio de experto en la definición de reglas óptimas. En primer lugar se reproducen los procesos de toma de decisiones actuales y, tras ello, el algoritmo de optimización estocástica se emplea para mejorar las reglas previamente obtenidas. La metodología propuesta en esta tesis se ha aplicado al sistema Júcar (Este de España), en el que los recursos hídricos son gestionados de acuerdo a complejos procesos de toma de decisiones. La aplicación se ha realizado de dos formas. En la primera, el algoritmo CSG-SDDP se ha utilizado para definir una estrategia óptima para el uso conjunto de embalses y acuíferos. En la segunda, la metodología se ha usado para reproducir las reglas de operación actuales en base a criterio de expertos. La herramienta desarrollada reproduce de forma explícita los procesos de toma de decisiones seguidos por los operadores del sistema. Dos sistemas lógicos difusos se han empleado e interconectado con este fin, así como regresiones difusas para predecir aportaciones. El Sistema de Ayuda a la Decisión (SAD) creado se ha validado comparándolo con los datos históricos. La metodología desarrollada ofrece a los gestores una forma sencilla de definir decisiones a priori adecuadas, así como explorar las consecuencias de una decisión concreta. La representación matemática resultante se ha combinado entonces con el CSG-SDDP para definir reglas óptimas que respetan los procesos actuales. Los resultados obtenidos indican que reducir el bombeo del acuífero de la Mancha Oriental conlleva una mejora en los beneficios del sistema debido al incremento de caudal por relación río-acuífero. Las reglas de operación han sido adecuadamente desarrolladas combinando lógica difusa, juicio experto y optimización estocástica, aumentando los suministros a las demandas mediante modificaciones el balance de Alarcón, Contreras y Tous. Estas reglas siguen los procesos de toma de decisiones actuales en el Júcar, por lo que pueden resultar familiares a los gestores. Además, pueden compararse con las reglas de operación actuales para establecer qué decisiones entreDonat l'alt nombre d'infraestructures construïdes en els països desenrotllats, i amb una oposició creixent a la construcció de noves infraestructures en els països en vies de desenrotllament, l'atenció de l'anàlisi de sistemes de recursos hídrics ha passat a la definició de regles d'operació adequades. Una gestió més eficient del recurs hídric és necessària per a poder afrontar els impactes del canvi climàtic i de la creixent demanda d'aigua. Per a aconseguir-ho, una amplia selecció de ferramentes i models matemàtics d'optimització s'han desenrotllat. No obstant això, la seua aplicació pràctica en la gestió hídrica continua sent limitada. Una de les més importants línies d'investigació per a solucionar-ho busca la col·laboració activa dels experts en la definició dels models matemàtics. Per a definir regles d'operació en les quals els gestors confien, és necessari tindre en compte el seu criteri expert i combinar-ho amb algoritmes d'optimització. La present tesi desenrotlla una metodologia, i les ferramentes necessàries per a aplicar-la, amb la finalitat de millorar l'operació de sistemes complexos de recursos hídrics. En estos, els processos de presa de decisions són complicats i se sustenten, almenys en part, en el juí expert dels gestors. Esta importància del criteri d'expert en les regles d'operació requereix ferramentes matemàtiques capaces d'incorporar-lo en la seua estructura i d'unir-lo amb algoritmes d'optimització. Les ferramentes i mètodes desenrotllats es basen en l'optimització estocàstica, en la lògica difusa i en la col·laboració activa dels experts durant tot el procés. Un algoritme estocàstic avançat, capaç de ser usat en sistemes complexos amb interaccions riu-aqüífer, s'ha desenrotllat (el CSG-SDDP) . La metodologia definida utilitza lògica difusa per a capturar el criteri d'expert en la definició de regles òptimes. En primer lloc es reprodueixen els processos de presa de decisions actuals i, després d'això, l'algoritme d'optimització estocàstica s'empra per a millorar les regles prèviament obtingudes. La metodologia proposada en esta tesi s'ha aplicat al sistema Xúquer (Est d'Espanya), en el que els recursos hídrics són gestionats d'acord amb complexos processos de presa de decisions. L'aplicació s'ha realitzat de dos formes. En la primera, l'algoritme CSG-SDDP s'ha utilitzat per a definir una estratègia òptima per a l'ús conjunt d'embassaments i aqüífers. En la segona, la metodologia s'ha usat per a reproduir les regles d'operació actuals basant-se en criteri d'experts. La ferramenta desenvolupada reprodueix de forma explícita els processos de presa de decisions seguits pels operadors del sistema. Dos sistemes lògics difusos s'han empleat i interconnectat amb este fi, al igual què regressions difuses per preveure cabdals. El Sistema d'Ajuda a la Decisió (SAD) creat s'ha validat comparant-lo amb les dades històriques. La metodologia desenvolupada ofereix als gestors una manera senzilla de definir decisions a priori adequades, així com per explorar les conseqüències d'una decisió concreta. La representació matemàtica resultant s'ha combinat amb el CSG-SDDP per a definir regles òptimes que respecten els processos actuals. Els resultats obtinguts indiquen que reduir el bombament de l'aqüífer de la Mancha Oriental comporta una millora en els beneficis del sistema a causa de l'increment de l'aigua per relació riu-aqüífer. Les regles d'operació han sigut adequadament desenrotllades combinant lògica difusa, juí expert i optimització estocàstica, augmentant els subministres a les demandes per mitjà de modificacions del balanç d'Alarcón, Contreras i Tous. Estes regles segueixen els processos de presa de decisions actuals en el Xúquer, per la qual cosa poden resultar familiars als gestors. A més, poden comparar-se amb les regles d'operació actuals per a establir quines decisions entre les possibles serien coherentsMacián Sorribes, H. (2017). Design of optimal reservoir operating rules in large water resources systems combining stochastic programming, fuzzy logic and expert criteria [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/82554TESI

    Australasian Groundwater Conference: Groundwater in a Changing World

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    © Copyright is retained by the author/s of each abstract.The Australasian Groundwater Conference (AGC) was held in Brisbane Queensland, 24-27 November 2019. This conference was an epic event filled with informative presentations, entertaining networking events and stunning field trips exploring the sights and sounds that this subtropical dynamic region has to offer. The AGC 2019 featured a stimulating technical program around the theme of “Groundwater in a Changing World” that covered a broad range of applications to resources, infrastructure and environment. The program included stimulating plenary speakers, engaging panel discussions and enticing social events. Over 600 groundwater researchers, industry professionals and policy development specialists from around the region attended this unique event. There were many opportunities on offer for delegates to share their experiences, inform best practice, and identify the steps they can take to bring about lasting improvements to the management of our vital groundwater resources. Our hard working volunteer organisational team wishes to thank sponsors, speakers, delegates, exhibitors and volunteers for making the conference such a huge success

    ISGSR 2011 - Proceedings of the 3rd International Symposium on Geotechnical Safety and Risk

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    Scientific standards applicable to publication of BAWProceedings: http://izw.baw.de/publikationen/vzb_dokumente_oeffentlich/0/2020_07_BAW_Scientific_standards_conference_proceedings.pd

    Proceedings of FORM 2022. Construction The Formation of Living Environment

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    This study examines the integration of building information modelling (BIM) technologies in operation & maintenance stage in the system of managing real estate that helps to reduce transaction costs. The approach and method are based on Digital Twin technology and Model Based System Engineering (MBSE) approach. The results of the development of a service for digital facility management and digital expertise are presented. The connection between physical and digital objects is conceptualized

    A hydrogeological study of the Kasteelberg Mountain aquifer, Western Cape, South Africa

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    Thesis (MSc)--Stellenbosch University, 2020.ENGLISH ABSTRACT: The availability of freshwater is one of the major factors that are limiting South Africa’s development. With this in mind the area under investigation in this study forms part of the Sandspruit catchment, which is about 100 km north-east of Cape Town near the town of Riebeek Kasteel. The climate is semi-arid with a Mediterranean landscape. This study forms part of multiple studies that were initiated to assist in alleviating the crisis brought about by the continuing drought in the Western Cape Province. This study investigated the possibility of utilising the Kasteelberg Mountain, located near the town of Riebeek Kasteel, as an additional source of freshwater. The regionally fractured sandstone aquifer was the focus during the modelling, volume and porosity calculations in this hydrogeological research of the Kasteelberg Mountain Aquifer. This resulted in an estimated water reserve that can be sustainably extracted. Sustainable development is needed to protect the sensitive ecosystems against anthropologic and climate-driven impacts. The study started with analysing the responses from water level loggers that were installed in boreholes in the study area to monitor the water fluctuations during the seasons so as to utilise this resource sustainably. During the study, the physical geology of the area was characterised. Geographic Information Systems (GISs) were used to generate maps and derive volumetric information needed to estimate water volumes, and this included the delineation of the watershed, elevation and the spatial maps of the boreholes that were monitored. A cascade model was created by using climate data collected from local weather stations and the physical character of the local sandstone to study the waterflow through the mountain. The cascade model was used to appraise its potential in runoff. Some common features between the proposed model and HYDRUS-1D runoff model are also discussed. Data was also used in the HYDRUS-1D model where the results generated were compared with the cascade model results and the measured results from fieldwork studies. The study therefore reflected on the volume of water present in the mountain aquifer and despite the area experiencing its worst drought in a century, this excess water was available for extraction.AFRIKAANSE OPSOMMING: Die studie-area vorm deel van die Sandspruit-opvangsgebied. Die klimaat is semi-droog en kan beskryf word as ’n bedreiging vir ontwikkeling. ’n Studie is gedoen met die hoop om ʼn addisionele varswaterbron te vind. Hierdie studie vorm deel van ʼn groter studie wat ten doel het om die droogtegeteisterde Wes-Kaap se druk te verlig deur addisionele varswaterbronne te vind. Die studie fokus op die Kasteelberg, wat net buite die dorp Riebeek Kasteel geleë is. Tydens hierdie hidrologiese ondersoek is daar gevind dat die akwifer hoofsaaklik bestaan uit sandsteen wat deel van die Tafelberg Groep vorm. Nate en krake is ook volop in hierdie poreuse sandsteenrotse. Vir die doeleindes van hierdie studie is die akwifer as homogeen met betrekking tot sy geologiese samestelling beskou. Die studie het grondwatervlakregistreerders geïnstalleer in bestaande boorgate om die seisoenale waterfluktuering te meet. Die fisiese karakterisering van die geologie is onderneem waar die totale porositeit en samestelling eerstens vasgestel is. Geografiese Inligtingstelsels (GIS)- sagteware is gebruik om die berg te karteer, asook die waterskeidings af te lei, oppervlaktes te bepaal, metings van die berg te doen en die verspreiding van die toetsboorgate te karteer. Plaaslike weerstasiedata is bekom en deur middel van die opstel van ’n kaskade-model in MS Excel is die geofisiese inligting ingespan om meer te ontdek van die water wat deur die berg vloei. Excel is dus ook gebruik om die volume van die akwifer te bepaal en die model kon die waterdravermoë van die akwifer benader. Excel-resultate is gevolglik vergelyk met die HYDRUS-1D-model se resultate en die model het die Excel-resultate bevestig en met fisiese waarnemings ooreengestem wat in die veld gemaak was. Die studie het daarin geslaag om te bewys dat hoewel die Wes-Kaap tans deur die ergste droogte in 100 jaar geteister word, die Kasteelberg Akwifer steeds genoeg neerslag ontvang om as waterbron vir plaaslike ontginning te dien, wat sodoende die druk op die bestaande waterinfrastruktuur sal kan verlig.Master

    Tracing back the source of contamination

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    From the time a contaminant is detected in an observation well, the question of where and when the contaminant was introduced in the aquifer needs an answer. Many techniques have been proposed to answer this question, but virtually all of them assume that the aquifer and its dynamics are perfectly known. This work discusses a new approach for the simultaneous identification of the contaminant source location and the spatial variability of hydraulic conductivity in an aquifer which has been validated on synthetic and laboratory experiments and which is in the process of being validated on a real aquifer

    An engineering geomorphological investigation of hillslope stability in the Peak District of Derbyshire

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    Large-scale civil engineering works, planning and land-management in areas known to have a landslide problem require regional landslide susceptibility evaluation. The Matrix Assessment Approach (MAP) is introduced as a technique for establishing an index of slope stability over large areas. The method allows the relative landslide susceptibility to be computed over large areas using a discrete combination of geological/geomorphological parameters. MAP was applied to a region in the Peak District, Derbyshire. The model identified key geological/geomorphological parameters involved in deep-seated failures, provided an effective means of classifying the stability of slopes over a large area and successfully indicated sites of previously unmapped landslides. The resultant regional landslide susceptibility index provides useful preliminary information for use at the pre-site/reconnaissance stages, of large-scale civil engineering works such as highway construction. Unlike deep-seated failures, shallow translational slides usually do not prevent the use of areas above and below the failure, however, they can cause considerable inconvenience and expense When remedial engineering works are necessary. An investigation was undertaken in order to establish the precise critical state of geomorphological factors involved in shallow translational landsliding in the Peak District. Back calculations based on the Infinite Slope Stability Model showed how the factor of safety against shallow translational sliding changed as one geomorphological parameter varied. The value of the factor of safety was very sensitive to changes in the values of effective cohesion and piezometric height, moderately sensitive to changes in the values of regolith depth and the angle of slope inclination and insensitive to changes in the values of angle of friction with respect to effective stresses and soil unit weight. The recognition of such meso/micro geomorphological thresholds is not only important for geomorphologists concerned with landform evolution, it is also fundamental to successful and safe engineering practices

    An engineering geomorphological investigation of hillslope stability in the Peak District of Derbyshire

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    Large-scale civil engineering works, planning and land-management in areas known to have a landslide problem require regional landslide susceptibility evaluation. The Matrix Assessment Approach (MAP) is introduced as a technique for establishing an index of slope stability over large areas. The method allows the relative landslide susceptibility to be computed over large areas using a discrete combination of geological/geomorphological parameters. MAP was applied to a region in the Peak District, Derbyshire. The model identified key geological/geomorphological parameters involved in deep-seated failures, provided an effective means of classifying the stability of slopes over a large area and successfully indicated sites of previously unmapped landslides. The resultant regional landslide susceptibility index provides useful preliminary information for use at the pre-site/reconnaissance stages, of large-scale civil engineering works such as highway construction. Unlike deep-seated failures, shallow translational slides usually do not prevent the use of areas above and below the failure, however, they can cause considerable inconvenience and expense When remedial engineering works are necessary. An investigation was undertaken in order to establish the precise critical state of geomorphological factors involved in shallow translational landsliding in the Peak District. Back calculations based on the Infinite Slope Stability Model showed how the factor of safety against shallow translational sliding changed as one geomorphological parameter varied. The value of the factor of safety was very sensitive to changes in the values of effective cohesion and piezometric height, moderately sensitive to changes in the values of regolith depth and the angle of slope inclination and insensitive to changes in the values of angle of friction with respect to effective stresses and soil unit weight. The recognition of such meso/micro geomorphological thresholds is not only important for geomorphologists concerned with landform evolution, it is also fundamental to successful and safe engineering practices

    Cone Penetration Testing 2022

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    This volume contains the proceedings of the 5th International Symposium on Cone Penetration Testing (CPT’22), held in Bologna, Italy, 8-10 June 2022. More than 500 authors - academics, researchers, practitioners and manufacturers – contributed to the peer-reviewed papers included in this book, which includes three keynote lectures, four invited lectures and 169 technical papers. The contributions provide a full picture of the current knowledge and major trends in CPT research and development, with respect to innovations in instrumentation, latest advances in data interpretation, and emerging fields of CPT application. The paper topics encompass three well-established topic categories typically addressed in CPT events: - Equipment and Procedures - Data Interpretation - Applications. Emphasis is placed on the use of statistical approaches and innovative numerical strategies for CPT data interpretation, liquefaction studies, application of CPT to offshore engineering, comparative studies between CPT and other in-situ tests. Cone Penetration Testing 2022 contains a wealth of information that could be useful for researchers, practitioners and all those working in the broad and dynamic field of cone penetration testing

    Spatial patterns of fine sediment supply and transfer in the River Esk, North York Moors.

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    A detailed field study of spatial and temporal patterns of fine sediment transfer was undertaken in the River Esk catchment, North York Moors in response to ecological problems associated with in-channel fine sedimentation. Fine sediment flux and specific sediment yields were estimated from bulk suspended sediment samples collected from a network of 17 spatially distributed Time Integrated Samplers (TIMS). These samplers were deployed over a six month monitoring period from December 2005 - June 2006.Channel characteristics (bank height; bank material; vegetation cover I type; and erosion extent I type); catchment properties (e.g. drains, tributaries and areas of saturated runoff); and land use were mapped using a stream reconnaissance survey covering 61 km of the River Esk and dominant tributaries. These mapped attributes were combined in ArcGIS with other spatial data (e.g. geology; land elevation and slope) to create a GIS database. Dominant sediment source areas were identified by comparing sediment characteristics (e.g. colour; magnetic susceptibility; and metal concentrations) of the suspended material retained in the TIMS samplers with those of channel bank and catchment source samples. Two main areas of high fine sediment flux were identified on the Esk between: Danby to Duck Bridge; and Egton Bridge to Grosmont. Fine sediment in the Danby to Duck Bridge reach was sourced predominantly from local channel banks as a result of geotechnical failures. However from Egton Bridge to Grosmont, catchment sediment sources, from the steep, forested, boulder clay sub-catchments of the dominant tributaries (Glaisdale Beck and Butter Beck), were most significant. To alleviate high level of sedimentation in these locations, the main areas requiring management are the channel banks of the Esk near Danby; intensively farm areas of Danby Beck and Great Fryup Beck; and the steep, wooded regions in Glaisdale Beck and Butter Beck sub-catchments. Suitable target initiatives should include: riparian fencing; bank reinforcements; livestock rotation; and the creation of buffer zones
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