Hölder Scales of Sea Level

The statistics of sea level is essential in the field of geosciences, ranging from ocean dynamics to climates. The fractal properties of sea level, such as long-range dependence (LRD) or long memory, 1/f noise behavior, and self-similarity (SS), are known. However, the description of its multiscale behavior as well as local roughness with the Hölder exponent h(t) from a view of multifractional Brownian motion (mBm) is rarely reported, to the best of our knowledge. In this research, we will exhibit that there is the multiscale property of sea level based on h(t)s of sea level data recorded by the National Data Buoy Center (NDBC) at six stations in the Florida and Eastern Gulf of Mexico. The contributions of this paper are twofold as follows. (i) Hölder exponent of sea level may not change with time considerably at small time scale, for example, daily time scale, but it varies significantly at large time scale, such as at monthly time scale. (ii) The dispersion of the Hölder exponents of sea level may be different at different stations. This implies that the Hölder roughness of sea level may be spatial dependent

Numerical investigation of river discharge and tidal variations impact on the salinity in deltaic systems

The present project is an effort to identify key parameters and controlling factors of salinity variations in deltaic systems. The salinity’s driving mechanisms and response to hydrodynamic changes are under investigation. This is demanded because of the risks that these ecosystems are subject to by increases of salinity due to sea level rise and human activities. Numerical modelling is implemented to study the salinity distribution in idealized deltas configuration under various hydrodynamic conditions. In particular, variations of the river discharge and tidal levels are considered. The results indicate that salinity undergoes significant seasonal changes due to dynamic flow variability. Sustained drought periods could result in critical conditions with salt intrusion in the delta’s trunk (fluvial) channel. On the contrary, high river discharges during wet periods could mix completely the vertical column with freshwater for at least some distance from the river mouth. Tides could contribute further in mixing improving the conditions in the delta by decreasing the salinity in the downstream delta areas. Hence, many tidally influenced deltas could contain higher freshwater volumes than river dominated systems. Nevertheless, tidal level increases could limit significantly the deltas freshwater availability in mesotidal or macrotidal regimes. Results analysis and implementation of simple and innovative techniques uncovered the existence of certain correlations that could be useful as prognostic tools of salinity. Channels classification by their class or number of links provides a correlation that shows the salinity to increase with the decrease of either the channels order or delta’s cross-section width. In addition, radial and depth averages of salinity are negatively and exponentially correlated with the river discharge. The extracted exponential equation summarizes successfully the complex 3D delta dynamics into a 1D analytical solution. The equation resembles theoretical solutions of the 1D advection-diffusion equations under certain theoretical assumptions of which many are satisfied in the present idealized models setup. The above correlations incur modifications when external (e.g. hydrodynamic forcing) or intrinsic (e.g. bathymetry) parameters cause changes to the spatial salinity distribution. Bathymetric effects affect the salinity distribution in both horizontal and vertical directions especially at low flow periods when the bottom friction becomes stronger. Increases of the river discharge and/or tidal level override these effects. This study aspires to provide knowledge that could be useful for the development of technical or non-technical solutions for the aversion of salinization issues in deltas. With the goal of contributing to the efforts for the development of environmentally friendlier solutions, the last part of this work investigates the effect of different shape but equal volume hydrographs on the salinity. The results show that it is possible to alleviate the consequences of increased salinity by better management of existing water resources instead of seeking for additional ones

YOUMARES 9 - The Oceans: Our Research, Our Future

This open access book summarizes peer-reviewed articles and the abstracts of oral and poster presentations given during the YOUMARES 9 conference which took place in Oldenburg, Germany, in September 2018. The aims of this book are to summarize state-of-the-art knowledge in marine sciences and to inspire scientists of all career stages in the development of further research. These conferences are organized by and for young marine researchers. Qualified early-career researchers, who moderated topical sessions during the conference, contributed literature reviews on specific topics within their research field

YOUMARES 9 - The Oceans: Our Research, Our Future

This open access book summarizes peer-reviewed articles and the abstracts of oral and poster presentations given during the YOUMARES 9 conference which took place in Oldenburg, Germany, in September 2018. The aims of this book are to summarize state-of-the-art knowledge in marine sciences and to inspire scientists of all career stages in the development of further research. These conferences are organized by and for young marine researchers. Qualified early-career researchers, who moderated topical sessions during the conference, contributed literature reviews on specific topics within their research field

Karst Rock Features

Rock features are important traces of the formation and development of karst surface. On various karren their record is especially rich, revealing to us the many factors that in diverse conditions formed the karst surface on various carbonate and other rock.We have tried to present the most characteristic rock features and through them the most important factors and processes in the formation of the karst surface, the methods of studying them, and the most outstanding examples.Forty-nine contributing authors offer a wide spectrum of content and examples of rock forms from many karst regions around the world.The first part of the book offers an orderly-organized survey and description of the most characteristic rock forms and presents the physical and chemical corrosion of rock, biocorrosion, the modeling of rock forms, their detailed morphometrics, and numerous descriptions of individual rock forms. The second part is devoted to various examples of rock forms found around the world from Slovenia through North and South America to Australia and Asia.Skalne oblike so pomembna sled oblikovanja in razvoja površinskih kraških pojavov. Še zlasti bogat je njihov zapis na različnih škrapljah. Razkriva nam številne dejavnike, ki v raznovrstnih razmerah oblikujejo kraško površje na različnih karbonatnih in drugih kamninah. Skušali smo zajeti najbolj značilne skalne oblike in skozi njih najbolj pomembne dejavnike in procese oblikovanja kraškega površja ter načine njihovega raziskovanja in najbolj izrazite primere. Širok spekter vsebine razkriva tudi nabor 49 avtorjev in primeri skalnih oblik s številnih kraških področji sveta. Prvi del knjige smiselno podaja pregled najbolj značilnih skalnih oblik in njihov opis, predstavlja fizikalno-kemično raztapljanje kamnine, biokorozijo, modeliranje skalnih oblik, njihovo podrobno morfometrijo ter številne opise posameznih skalnih oblik. Drugi del knjige je posvečen različnim primerom skalnih oblik širom sveta od Slovenije, prek severne in južne Amerike do Avstralije in Azije

YOUMARES 9 - The Oceans: Our Research, Our Future

This open access book summarizes peer-reviewed articles and the abstracts of oral and poster presentations given during the YOUMARES 9 conference which took place in Oldenburg, Germany, in September 2018. The aims of this book are to summarize state-of-the-art knowledge in marine sciences and to inspire scientists of all career stages in the development of further research. These conferences are organized by and for young marine researchers. Qualified early-career researchers, who moderated topical sessions during the conference, contributed literature reviews on specific topics within their research field

XXXV Congress of the International Association of Hydrogeologists, Groundwater and Ecosystems – Abstract Book

Resumos das comunicações do XXXV Congresso da Associação Internacional de Hidrogeólogos (IAH