Search results for " sedi"

Non-uniform Sediment Transport Estimation in Non-equilibrium Situations: Case Studies

2014

Abstract Quantitative estimate of sediment transport in alluvial channels is one of the most important task in river engineering. Even today, numerical models of sediment transport processes are confronted with some difficulties, often of conceptual nature. One of these difficulties is the simulation of non-uniform sediment transport in non-equilibrium situations, which requires the characterization of the ability of the alluvial system to immediately overcome the variations of the sediment boundary conditions. In this work a 1-D numerical model, which includes a new expression of the so-called “adaptation coefficient”, has been applied to test its capability to simulate the transient bed p…

Le Quaternaire franc-comtois. Essai chronologique et paléoclimatique.

1982

Le but de ce travail est d'établir le cadre chronologique et paléoclimatique du Quaternaire en Franche-Comté à partir de l'étude des formations édifiées au cours de cette période.Deux grands types de dépôts ont été plus particulièrement étudiés: ·- Les remplissages karstiques d'avens, de porches de grottes et d'abris sous roche, donnant un éclairage intense, mais ponctuel, de l'environnement physique et biologique, grâce aux faunes abondantes et aux indices climatiques d'ordre sédimentologique.- Les dépôts glaciaires et paraglaciaires (moraines, fluvioglaciaires, glacio-lacustres) qui permettent de situer des coupures climatiques au cours du temps dans l'espace géographique étudié.L'étude d…

Modelling biogeochemical processes in sediments from the north-western Adriatic Sea: response to enhanced particulate organic carbon fluxes

2018

This work presents the result of a study carried out in the north-western Adriatic Sea, by combining two different types of biogeochemical models with field sampling efforts. A longline mussel farm was taken as a local source of perturbation to the natural particulate organic carbon (POC) downward flux. This flux was first quantified by means of a pelagic model of POC deposition coupled to sediment trap data, and its effects on sediment bioirrigation capacity and organic matter (OM) degradation pathways were investigated constraining an early diagenesis model by using original data collected in sediment porewater. The measurements were performed at stations located inside and outside the ar…

Signatures terrigène et volcanique des bassins sédimentaires : implications stratigraphiques et paléoclimatiques

2018

Influence de différentes pratiques agricoles sur la qualité et la santé des sols : étude de cas sur des vergers slovènes irrigués ou en agriculture b…

2011

Underestimation of soil properties and poor understanding of soil conditions can have many negative consequences, which results in quality or quantity of yield, soil degradation or even environmental pollution. According to importance of agricultural practices, our study focused on their impact on soil quality and health. The research took place from November 2003 to October 2007 in apple orchards in north-eastern Slovenia where two frequent agricultural practices were investigated: (i) drip irrigation on Calcaric Cambisol and its effects on structural stability and microbial biomass at Gačnik experimental station and (ii) combination of organic fertiliser (Campo guano) and liming in organi…

A high-quality annually laminated sequence from Lake Belau, Northern Germany: Revised chronology and ist implications for palynological and tephrochr…

2012

International audience; The annually laminated record of Lake Belau offers an exceptional opportunity to investigate with high temporal resolution Holocene environmental change, aspects of climate history and human impact on the landscape. A new chronology based on varve counts, 14C-datings and heavy metal history has been established, covering the last 9400 years. Based on multiple varve counting on two core sequences, the easily countable laminated section spans about 7850 varve years (modelled age range c. 9430 to 1630 cal. BP). Not all of the record is of the same quality but approximately 69% of the varves sequence is classified to be of high quality and only c. 5% of low quality. The …

Anthropogenic impact and environmental evolution of the last 55 years of the Gulf of Palermo (Sicily, Italy)

2009

Architetti e Ingegneri del Banco di Sicilia tra Ottocento e Novecento

I cambiamenti che interessano il mondo dell’architettura nel passaggio tra l'800 e il '900 coinvolgono anche il Banco di Sicilia che parteciperà attivamente alla ricerca di nuovi linguaggi e alla configurazione di nuove realtà urbane, a partire dalla prima metà del Novecento fino al programma di ricostruzione del secondo dopoguerra. L’attività legata all’edilizia e alla realizzazione delle proprie architetture spinge l’Istituto a formare un vero e proprio albo di tecnici di fiducia in cui si ritrovano importanti nomi di architetti e ingegneri che soprattutto nei primi trent’anni del ‘900 vengono chiamati a ricoprire ruoli più o meno prestigiosi. Gli estremi cronologici del periodo esaminato…

Nonuniform sediment transport estimation in non-equlibrium situations: study cases

2014

THE EFFECT OF HEAVY METALS ON BENTHIC FORAMINIFERA IN THE GULF OF GELA (SICILIAN CHANNEL)

2011

Benthic foraminifera are very sensitive to oceanographic parameter variations, to which they rapidly response through changes in the abundance and/or richness of their associations and in morphological variations of their shell. Many studies have used benthic foraminifera as bioindicators. We investigated recent benthic foraminiferal assemblages in the Gulf of Gela (Sicilian Channel, Mediterranean Sea), examining their relative abundance, specific richness and morphological abnormalities, to highlight a possible correlation with oceanographic features and the concentration of heavy metals in sediments. Sediment was sampled in summer 2006 using box corers in four stations at increasing dista…