Doctoral School

Reading date: 19/06/2026

• ALHARFOUCH, LOUJAIN: Integrating ecohydrological, isotopic, and numerical approaches to assess water use by montane Scots pine under varying wetness conditions
  
  Author: ALHARFOUCH, LOUJAIN
  Programme: DOCTORAL DEGREE IN GEOTECHNICAL ENGINEERING
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Normal
  Deposit date: 14/05/2026
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: HIDALGO GONZÁLEZ, JUAN JOSÉ | LATRON, JÉRÔME
  Thesis abstract: Ecohydrology provides a critical framework for understanding interactions between vegetation and the hydrological cycle, particularly in forested ecosystems that strongly regulate water fluxes and ecosystem resilience. In Mediterranean mountain regions, increasing climate variability and recurrent droughts place forests close to their hydraulic limits. Despite these mounting pressures, key uncertainties remain regarding how trees access, store, and utilize water across contrasting wetness conditions, and how these processes can be represented in ecohydrological models.This thesis investigates tree water uptake dynamics and their representation by integrating high temporal- and spatial-resolution field observations, stable water isotopes, and process-based modeling. The study was conducted in the Vallcebre Research Catchments (NE Spain), focusing on Scots pine (Pinus sylvestris L.). Field observations combined meteorological measurements, sap flow and stem diameter variations, soil water content and potential, groundwater levels, and weekly water stable isotopes sampling of precipitation, soil water, groundwater, and xylem water. These data were analyzed using statistical approaches and numerical modeling to examine tree water uptake at the plot scale during contrasting dry and wet periods.Field-based ecohydrological and isotopic analyses revealed that Scots pine water use is strongly constrained by soil water potential during drought, with trees relying on internal stem water storage and showing limited coupling to recent precipitation inputs. Stable isotope evidence demonstrated a dominant contribution of winter-recharged soil water stored in tightly bound soil pores, even following intense summer rainfall events. Only after sustained soil rewetting did trees begin incorporating summer precipitation, ultimately sourcing water from a mixture of winter and summer inputs. These findings indicate a clear preference for stable water pools with longer residence times and highlight the critical role of winter precipitation in sustaining tree hydraulic functioning in Mediterranean mountain forests.Building on these plot-scale observations, the second part of the thesis develops a physically grounded, calibration-free root water uptake parameterization based on soil moisture drying rates and constrained by sap-flow-derived transpiration. When implemented in a numerical model, this approach consistently outperformed commonly used empirical root distribution functions in reproducing soil water content and soil water potential dynamics. Independent validation using stable water isotopes confirmed the robustness of the proposed modeling framework and revealed tree water-use patterns under dry and wet conditions that were consistent with the field-based ecohydrological and isotopic findings.Agreement between field-based and modeling-based findings demonstrates that integrating ecohydrological observations, stable isotopic tracers, and physically grounded modeling provides a coherent and robust framework for advancing understanding of tree water uptake. The research in this thesis contributes to improving the realism of root water uptake representations in ecohydrological models and emphasizes the importance of stored winter precipitation for forest resilience in water-limited environments.
  

• BEA TORRAS, OSCAR: Disseny experiencial d’un mètode per a la planificació estratègica de la transformació digital a les pimes.
  
  Author: BEA TORRAS, OSCAR
  Programme: DOCTORAL DEGREE IN ENGINEERING, SCIENCES AND TECHNOLOGY EDUCATION
  Department: Institute of Education Sciences (ICE)
  Mode: Normal
  Deposit date: 29/05/2026
  Reading date: 19/06/2026
  Reading time: 15:00
  Reading place: Sala de Juntes - FIB
  Thesis director: PASTOR COLLADO, JUAN ANTONIO
  Thesis abstract: This thesis presents the applied research conducted by the doctoral researcher over the last few years in the framework of an industrial doctorate project, based on his long experience as a manager and IT consultant and his academic study of the subject, with the guidance of his supervisor and the collaboration of PIMEC, the main association of small and medium-sized enterprises (SMEs) in Catalonia, on the design, construction and validation of a new method for the strategic planning of digital transformation for SMEs, especially Catalan ones—a method that, as far as we know, will be the first method published in the world for this specific purpose.The method is based on the study of the state of the art of the subject, mainly the strategic planning of information systems and technologies for large companies and digital business transformation, and on the doctoral researcher’s professional experience in supporting SME management in addressing IT challenges, including systems planning. The industrial research project was grounded in the use of action design research (ADR), the most suitable research methodology approach for the theoretical-practical scenario presented. The aim was to propose a rigorous, ad hoc, adaptive planning method applicable to real SME business contexts and designed for the business, organisational, human and technological particularities of this type of company.The method articulates the digital transformation process around the three areas that compose it—business strategy, digital applications and technologies, and people—and provides a set of practical tools, guided by tables to support the analysis, integration and prospective formulation of these areas, and the systematic aggregation and formalisation of a plan or roadmap for digital transformation projects, including organizational and digital projects accompanied by staff training plans, both of which are necessary and advisable for managing organisational change and later successfully deploying the whole digital transformation plan in the SME.The method’s design prepares it for adaptability and iterative application, allowing various levels of application depending on the SME’s digital maturity and the availability of resources. This flexibility makes it possible for organisations to advance gradually and satisfactorily in their digital transformation process, thereby ensuring that strategic decisions are grounded in solid analyses and aligned with the nature of the SME’s business and its real possibilities for business innovation through current digital projects, applications and technologies.
  

• BRESSANELLI TEIXEIRA, ARTUR: Aggregates Production from Construction and Demolition Waste (CDW)
  
  Author: BRESSANELLI TEIXEIRA, ARTUR
  Programme: DOCTORAL DEGREE IN NATURAL RESOURCES AND THE ENVIRONMENT
  Department: Department of Mining, Industrial and ICT Engineering (EMIT)
  Mode: Article-based thesis
  Deposit date: 29/05/2026
  Reading date: 19/06/2026
  Reading time: 14:00
  Reading place: Aula 2.4 de l'EPSEM
  Thesis director: OLIVA MONCUNILL, JOSEP | HOFFMANN SAMPAIO, CARLOS
  Thesis abstract: The construction sector is the main source of solid waste in the European Union (EU), producing between 310 and 700 million tons. Over 30% of the solid waste generated comes from construction, demolition and renovation activities, including household waste. The waste produced by the construction sector is called Construction and Demolition Waste (CDW), mainly consisting of inert materials like concrete, brick, ceramics, plaster, and aggregates, which make up more than 75% of the waste volume. Materials such as wood, metals, glass, and organic material account for the remaining 25%. The demand for raw materials used as aggregates exceeds 2.7 billion tons annually, and the extraction sector is responsible for emitting 6 billion tons of CO2. As modern society develops and the need for infrastructure, access roads, building, and renovation increases, CDW generation is expected to rise. This trend has sparked academic discussions on recycling the material and reusing the aggregates it contains.The industry's primary use of this material is as road sub-bases, which reduces its added value and makes the operation financially unviable in some cases. Several research projects are currently underway to recover materials from CDW and reuse them, reducing the carbon footprint in the civil construction sector and the extraction of raw materials for industry. This doctoral thesis aims to test the feasibility of recovering and reusing aggregates from CDW using jigging as a gravity-concentration process. This concentration process is based on the stratification of materials in CDW according to the density relationship between particles, allowing recovery of the dense particles (aggregates). In parallel with this research, an economic analysis of investment was carried out, considering the CAPEX, OPEX, revenue, IRR, MIRR, NPV, and DPP of the different aggregates concentrating and recovering plants. In the analysis, three CDWs with different characteristics were analyzed in concentrating plants that use water jigs, air jigs, and sensor-based sorting.This thesis examines the material dynamics during the jigging process, focusing on the material’s physical properties. Factors such as specific density, apparent density, shape factor, water absorption, densimetric distribution, concrete substrate analysis, and the ratio of cement paste adhered to the material are quantified to understand how the jig separates aggregates from impurities. Studies were conducted on ternary (concrete, bricks, and stones from old houses), binary (concrete and bricks), and unitary (concrete) mixtures to evaluate the effectiveness of jigging in recovering aggregates. Afterwards, the recovered aggregates were used to produce new concrete mixes to assess the feasibility of reusing the material through compression tests with 25%, 50%, 75%, and 100% replacement of natural aggregates (NA) with recycled aggregates (RA). The comprehensive study enabled the development of a recovery process for the aggregates in CDW, confirmed the process’s reproducibility, and demonstrated the high purity potential of the recovered aggregates. Tests on producing new concretes with the recycled material also confirmed its viability for reintegration into new concrete. The economic analysis results indicated that water jigs are the most cost-effective method for concentrating aggregates compared to water jigs combined with sensor-based sorting. This investigation established a CDW beneficiation route, analyzing the technical, environmental, and economic feasibility of CDW processing.This work supports the academic community's efforts to reduce solid waste production and develop new materials for the civil construction sector, thereby decreasing the carbon footprint of the civil and mining industries.
  

• CARRILLO LOSADA, MARÍA PAULA: Effects of pollution on invertebrate-associated microbiomes across freshwater and marine systems
  
  Author: CARRILLO LOSADA, MARÍA PAULA
  Programme: DOCTORAL DEGREE IN MARINE SCIENCES
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Article-based thesis
  Deposit date: 20/05/2026
  Reading date: 19/06/2026
  Reading time: 10:00
  Reading place: Place: ETSECCPBUPC, Campus NordBuilding C2. Classroom: 212C/Jordi Girona, 1-308034 Barcelona
  Thesis director: BARATA MARTI, CARLOS | VILA COSTA, MARIA
  Thesis abstract: Human activities have driven major environmental alterations, including the release of synthetic chemicals that exceed our capacity to assess their ecological impacts. Aquatic ecosystems, acting as major sinks for contaminants, are exposed to complex pollutant mixtures differing in persistence, bioaccumulation and toxicity. However, conventional ecotoxicological approaches, largely based on chemical analyses and simplified exposures, often fail to capture the biological consequences of chronic, low-dose and mixture exposures. Moreover, early integrative indicators of exposure remain poorly developed, while omics-based research is strongly biased towards vertebrates, limiting understanding in ecologically dominant groups such as invertebrates.This thesis evaluates invertebrate-associated microbiomes as potential bioindicators of pollutant exposure across freshwater and marine environments. Laboratory experiments and field studies were integrated to assess microbiome responses, compare experimental and environmental patterns, and explore links between microbial shifts and host health. Model organisms, including Daphnia magna and the marine copepod Paracartia grani, were studied alongside natural populations such as Antarctic amphipods and Hydropsyche exocellata. Field campaigns included Mediterranean rivers impacted by wastewater discharges, a trans-Atlantic pollution gradient and Antarctic coastal systems. Microbiome responses were characterized using 16S rRNA gene sequencing, complemented by chemical analyses and host health endpoints.Across all studies, pollutant exposure consistently altered host-associated microbiomes, regardless of habitat, host species or pollutant class. These shifts were reproducible and often involved enrichment or depletion of specific taxa, supporting the hypothesis that microbiomes capture early biological responses to chemical stress. Host-associated microbiomes were generally more sensitive than environmental bacterial communities, particularly for bioaccumulative and hydrophobic contaminants, which induced more persistent perturbations than more polar compounds.Although no universal microbial indicator was identified, consistent context-dependent patterns emerged. In marine systems, taxa such as Pseudoalteromonas, Alteromonas and Rhodobacteraceae were repeatedly associated with organic pollutant exposure, while freshwater studies highlighted taxa linked to antibiotic resistance and wastewater influence, including Microbacterium and Microtrichaceae. Recurrent enrichment of broader groups such as Proteobacteria further suggests that functional traits, including xenobiotic degradation capacity, may underpin consistent responses.Links between microbiome perturbations and host health were also identified. In D. magna, microbioplastics exposure reduced Limnohabitans and increased Pseudomonas, coinciding with impaired reproduction, altered behaviour and transcriptomic changes. In copepods, shifts in core microbiome composition were associated with reduced reproductive output. While these results support links between microbiome disruption and host fitness, causality remains unresolved.Overall, this thesis demonstrates that invertebrate-associated microbiomes provide a sensitive and ecologically relevant approach to assess pollution exposure in aquatic ecosystems. Despite challenges regarding standardization and causal inference, the proposed framework aligns with new approach methodologies (NAMs) and offers strong potential for future integrative biomonitoring under increasing global chemical pressure.
  

• CARRION BERTRAN, NIL: Influence of topobathymetric and offshore forcing uncertainties on beach morphodynamic predictability
  
  Author: CARRION BERTRAN, NIL
  Programme: DOCTORAL DEGREE IN MARINE SCIENCES
  Department: Department of Civil and Environmental Engineering (DECA)
  Mode: Normal
  Deposit date: 11/05/2026
  Reading date: 19/06/2026
  Reading time: 10:30
  Reading place: FIB. Campus Nord. Sala d'Actes Manuel Martí Recober B6 Planta 0
  Thesis director: CALVETE MANRIQUE, DANIEL | RIBAS PRATS, FRANCESCA
  Thesis abstract: Sandy beaches are among the most important, yet most vulnerable, environments on Earth. These regions are home to over 30% of the world's population and host a vast array of socioeconomic activities. As the interface between sea and land, they are highly dynamic systems where numerous processes occur at different temporal and spatial scales, continuously reshaping the morphology of the coast. Furthermore, climate change could modify these processes, producing not only long-term effects but also, in the short and medium term, impacts that significantly affect beach morphology.In order to investigate these effects, morphodynamic numerical models are key tools, allowing the analysis of past and present conditions, as well as to explore future scenarios. However, their application involves several sources of uncertainty. This thesis focuses primarily on uncertainties related to offshore forcing and initial topobathymetric conditions across multiple temporal and spatial scales.In the short term, the process-based XBeach model was employed to develop a conceptual model of how the initial topobathymetry influences the generation of washover deposits on a synthetic beach inspired by Castelldefels data (Spain) during a storm event. The study highlighted the importance of using detailed initial topobathymetries that incorporate potential morphological patterns to accurately analyse washover deposit generation. In particular, the inclusion of morphological patterns with varying wavelengths was shown to significantly affect hydrodynamic behaviour and sediment transport patterns, thereby influencing the distribution, extent, and volume of washover deposits. For instance, the presence of megacusps of certain wavelengths could enhance washover deposition by up to a factor four compared to scenarios in which such patterns were not included. This study proved the significant potential modelling uncertainties linked to unknowns not only in the initial topobathymetry but also in the incident wave group chronology, which can be included in this model, and may have a stronger influence on washover deposit formation than variations in the initial cross-shore profile. In the medium term, both the process-based XBeach model and the reduced-complexity Q2Dmorfo model were used to investigate how different hydrodynamic forcing sources, including waves and sea level, affect the modelling of the embayed Castell Beach (Palamós, Spain) over a six-month period. The study demonstrated that inaccurate representations of wave conditions can significantly affect the modelling of an embayed beach in the medium term, whilst different sea level sources produced similar results. In particular, biases in wave direction from hindcast data resulted in poor representations of shoreline evolution, although the model could recover if hindcast data was only employed for only a couple of months. These results highlight the uncertainties related with the selection of forcing sources to simulate the evolution of an embayed beach.In the long term, the Q2Dmorfo model was employed to investigate the influence of wave storm chronology on the projected evolution of the Llobregat Delta up to 2100. The study highlighted the strong dependence of the model response on the initial adaptation period, which appeared to be influenced by the wave chronology. However, once the model reached a quasi-equilibrium state during this adaptation phase, the subsequent low dynamism, resulting from the model calibration, was primarily controlled by the resulting topobathymetry rather than by the wave chronology. Consequently, the multiple realisations performed converged towards a similar morphological response up to 2100, limiting the ability to assess the role of storm chronology in long-term shoreline evolution. To address this limitation, several methodological improvements are proposed, with the objective of capturing the potential role of wave chronology in further work.