2024 / Salt marshes are dynamic coastal environments that continuously undergo lateral and vertical changes due to erosion and sedimentation dynamics that are mediated by physical and biological processes. This dissertation focuses on edge erosion and the drivers behind this form of marsh loss, as well as sedimentation of the marsh platform from storms and the potential sources of these sediment influxes. By studying these erosion and sedimentation dynamics in a variety of marshes, this dissertation contributes to our understanding of sediment movement in marsh systems and the drivers of marsh loss and resilience. The marsh edge is vulnerable to wave attack, which can dislodge sediment or induce mass failure through undercutting and destabilizing action of the edge. Vegetation and geotechnical properties affect the erodibility of the marsh edge, and all these factors interact to enhance or mitigate edge erosion and produce certain marsh edge morphologies. The first chapter of this dissertation investigates these different parameters and their relationship to the type and distribution of edge erosion occurring in the Great Marsh, Massachusetts. This work demonstrates that there is no clear relationship among wind fetch, geotechnical properties, and the type of edge erosion observed because of heterogeneity of the marsh. Marsh edges can erode in both exposed and sheltered areas, and the geotechnical characteristics of the marsh edge do not serve as indicators of edge erosion. Parameters and processes beyond those generally ascribed to be the drivers of edge erosion may therefore be responsible for marsh loss. The second chapter takes a closer look at the relationship between waves and marsh shoreline retreat, as the nature of this relationship can help predict marsh loss under varying wind and wave conditions, as well as have implications on the impact of storms on edge erosion and marsh loss. This study shows that there is no universal or generalizable linear relationship between wave power and retreat as previously suggested, but rather the relationships between these parameters are site-specific and are often not linear at all. As a result, in one marsh, storms may have an outsized impact on retreat, while in another marsh more moderate wind-wave conditions may contribute to most of the retreat. Thus, it is important to calibrate these relationships for each marsh to fully constrain marsh loss due to wave attack and predict future marsh erosion. This work further highlights the importance of utilizing statistically robust analyses and regressions to investigate these relationships. Whereas storms contribute to marsh loss via edge erosion, they can also enhance vertical accretion and resilience of marshes to sea level rise (SLR) through storm-driven sediment transport and deposition. Major storms such as hurricanes can provide most of the inorganic sediment delivered to the marsh platform, though the source of these sediments is less understood for southeastern USA. Chapter 3 of this dissertation characterizes foraminifera communities in Hurricane Irma deposits in Sapelo Island, Georgia and compares them with the communities of surrounding sediment reservoirs to investigate the provenance of these storm-derived deposits. The foraminifera in the hurricane deposits resembled the foraminifera found in the surrounding marsh, rather than nearby sediment reservoirs such as tidal flats, channels, and offshore sediments. These similarities between the storm and marsh foraminifera assemblages are attributed to a mix of two processes: resilience of marsh foraminifera and rapid recolonization of these communities in the storm deposits following the passage of Hurricane Irma, and some reworking of marsh sediments into the storm deposits during the hurricane’s storm surge. The study also assesses the utility of foraminifera in identifying storm deposits, which has implications for the sensitivity of foraminifera paleostorm studies.

Esta tese apresenta um estudo da integração das características geológico geotécnicas da região de São Carlos que condicionam o processo de recarga do aquífero constituído pelos arenitos da Formação Botucatu. Dentre as características avaliadas, destacam-se os parâmetros de condutividade hidráulica, de retenção de poluentes e de distribuição de poros, além das informações sobre a distribuição e ocorrência dos materiais geológicos, profundidade do nível de água, uso do solo e superfícies de difração hídrica. Tais informações foram obtidas a partir de trabalhos integrados de escritório, campo e laboratório, sendo os resultados gerados na forma de mapas considerados fundamentais para a elaboração de modelos destinados à avaliação de recarga. Foi também realizado na região monitoramento pluviográfico das chuvas, bem como dos níveis de água e de umidade da zona não saturada através de poços e tensiômetros, respectivamente. As informações integradas e os dados de monitoramento foram utilizados em simulações no programa Mike-She, que considerou os diferentes aspectos geológico-geotécnicos no estudo de avaliação das taxas de recarga. O estudo demonstrou a importância da variabilidade dos materiais geológicos, das características geológico-geotécnicas e da dinâmica das águas para a adequada avaliação das taxas de recarga de aqüífero e de fluxo dos poluentes. / This thesis presents an integrated study of the geological and geotechnical characteristics of São Carlos region which influence the recharge process of the aquifer composed of sandstones of the Botucatu Formation. Among the assessed characteristics, it can be distinguished the parameters of ydraulic conductivity, retention of pollutants and pore distribution, also information about the distribution and occurrence of the geologic materials, groundwater depth, land use and water diffraction surfaces. Such data were obtained from desk study, field and laboratory integrated works, with the results being generated in the form of maps considered fundamental to the development of models for recharge assessment. In the region, it was also conducted monitoring of rainfall, groundwater levels and water content of the unsaturated zone through pluviograph, monitoring wells and tensiometers, respectively. The integrated information and monitoring data were used in the Mike-She software simulations, which considered the different geological and geotechnical aspects in the study for assessment of the recharge rates. The study demonstrated the importance of variability of geological materials, geological and geotechnical characteristics and dynamics of water for the adequate assessment of the aquifer recharge and transport of pollutants.

Esta tese apresenta um estudo da integração das características geológico geotécnicas da região de São Carlos que condicionam o processo de recarga do aquífero constituído pelos arenitos da Formação Botucatu. Dentre as características avaliadas, destacam-se os parâmetros de condutividade hidráulica, de retenção de poluentes e de distribuição de poros, além das informações sobre a distribuição e ocorrência dos materiais geológicos, profundidade do nível de água, uso do solo e superfícies de difração hídrica. Tais informações foram obtidas a partir de trabalhos integrados de escritório, campo e laboratório, sendo os resultados gerados na forma de mapas considerados fundamentais para a elaboração de modelos destinados à avaliação de recarga. Foi também realizado na região monitoramento pluviográfico das chuvas, bem como dos níveis de água e de umidade da zona não saturada através de poços e tensiômetros, respectivamente. As informações integradas e os dados de monitoramento foram utilizados em simulações no programa Mike-She, que considerou os diferentes aspectos geológico-geotécnicos no estudo de avaliação das taxas de recarga. O estudo demonstrou a importância da variabilidade dos materiais geológicos, das características geológico-geotécnicas e da dinâmica das águas para a adequada avaliação das taxas de recarga de aqüífero e de fluxo dos poluentes. / This thesis presents an integrated study of the geological and geotechnical characteristics of São Carlos region which influence the recharge process of the aquifer composed of sandstones of the Botucatu Formation. Among the assessed characteristics, it can be distinguished the parameters of ydraulic conductivity, retention of pollutants and pore distribution, also information about the distribution and occurrence of the geologic materials, groundwater depth, land use and water diffraction surfaces. Such data were obtained from desk study, field and laboratory integrated works, with the results being generated in the form of maps considered fundamental to the development of models for recharge assessment. In the region, it was also conducted monitoring of rainfall, groundwater levels and water content of the unsaturated zone through pluviograph, monitoring wells and tensiometers, respectively. The integrated information and monitoring data were used in the Mike-She software simulations, which considered the different geological and geotechnical aspects in the study for assessment of the recharge rates. The study demonstrated the importance of variability of geological materials, geological and geotechnical characteristics and dynamics of water for the adequate assessment of the aquifer recharge and transport of pollutants.

La presente tesis se estudia el fenómeno de licuefacción del material de relave en la presa zona norte en la mina cobriza, considerando que está sometida a una carga sísmica, valor obtenido a partir de un análisis de peligro sísmico considerando las fuentes sismogénicas históricas de la zona y posteriormente se determina una aceleración mínima necesaria donde iniciaría el proceso de licuefacción. Esta tesis tiene por objetivo identificar los factores que influyen en la falla por licuación en el material de relave Zona Norte en la mina Cobriza para evitar problemas de contaminación de suelos, calidad de agua y la posibilidad de ocasionar problemas en la planta concentradora que se encuentra al pie de la presa. Asimismo, se presenta información de definiciones sobre el fenómeno de licuación de suelos y mencionan casos históricos conocidos tanto a nivel mundial como en el Perú sobre los efectos ocasionados por este fenómeno. Posteriormente, se mencionan los estudios realizados para el reconocimiento y caracterización geotécnica del material de relave, así como el procesamiento de dicha información para poder evaluar el potencial de licuación donde se obtiene un factor de seguridad, el cual es un número que representa el potencial de licuefacción en el suelo. Finalmente, se concluye que los resultados demuestran la existencia de un alto potencial de licuación del material de relave en la presa zona norte en la mina cobriza considerando una aceleración de las fuentes sismogénicas históricas y se calcula un factor de seguridad de licuefacción de valor promedio de 1.3, con la finalidad de determinado la aceleración mínima necesaria donde iniciaría el proceso de licuefacción del material de relave. This thesis studies the phenomenon of liquefaction of tailings material in the dam in the northern copper mine is studied, considering that is subjected to a seismic load value obtained from a seismic hazard analysis considering the historic earthquake of gene sources area and then a necessary minimum acceleration which begin the process of liquefaction is determined. This thesis aims to identify the factors that influence the failure by liquefaction in the North Zone tailings material in the Cobriza mine to avoid problems of soil pollution, water quality and the ability to cause problems in the concentrator plant found at the foot of the dam. Also, information on the definition of soil liquefaction phenomenon occurs both known and mentioned about the effects caused by this global phenomenon and Peru historical cases. Subsequently, studies for the recognition and geotechnical characterization of the tailings material and processing of such information are mentioned in order to assess the potential of liquefaction where a safety factor, which is a number that represents the potential is obtained soil liquefaction. Finally, we conclude that the results show that there is a high potential for liquefaction of tailings material in the dam north in the copper mine considering an acceleration of historical seismic sources and a safety factor of liquefaction average value is calculated 1.3, in order to set the required minimum acceleration which begin the process of liquefaction of tailings material.

The topic of this master's thesis are the design of ensuring foundation pit and foundation of administrative building in Prague. In the vicinity of foundation pit is situated the river Vltava, which directly influences the ground water level at the job site. During construction, it is necessary to envisage the possibility of occurrence of the old building structures of docks.