Search results for "Fluvial"

Assessing, measuring and modelling erosion in calanchi areas: A review

2016

Calanchi are erosion landforms characterised by a heavily dissected terrain with steep, unvegetated slopes and channels with a dendritic pattern, which rapidly incise and extend headwards. Recent literature focusing on badland systems highlights their similarity with other larger fluvial landforms, stating that these behave as a full size laboratory, due to their rapid development in space and time and to the diversity of geomorphic processes involved. In this paper, a brief review of the most important results on badland research is firstly presented. Then, the morphometric similarity between calanchi and other erosion landforms is discussed. Finally, models quantitatively relating the vol…

Contribution of HVSR measures for seismic microzonation studies

2018

The HVSR method applied to seismic noise can be a very useful technique to map the site effects of the territory, to identify the thickness of the soft covering and so the depth of the seismic bedrock. The case of the urban area of Oliveri is presented. Because of its high seismic hazard this area has been subject of first level seismic microzonation. The town lies on a large coastal plain made of mixed fluvial/marine sediments, overlapping a deformed substrate. In order to identify points on the area probably suffering of relevant site effects and to define a preliminary Vs subsurface model, 23 HVSR measurements were performed. A clustering technique of continuous signals has been used to …

Calcitic radial palisadic fabric in freshwater stromatolites: diagenetic and recrystallized feature or physicochemical sinter crust?

1999

Abstract When favorable conditions occur for carbonate precipitation (physicochemical processes) in tufas and travertines, organisms intervene either directly (the framework created by organisms acts as a crystal support) or indirectly (organic products influencing the mineralogy, nucleation, growth and habit of primary crystals). In the literature, fluvial and travertine crystalline sparite crusts with palisadic or prismatic crystals are generally interpreted as the result of early recrystallization of micrite in algal buildups (mostly composed of Schizothrix). Therefore, biological mediation is essential for the construction of continental bioherms and biostromes, even if organic remains …

ANTECEDENTES DEL ABASTECIMIENTO DE MADERA EN LA RIBERA DEL JÚCAR

2015

Wood's supply was an essential aspect for the Kingdom of Valencia during the medieval centuries. The large plain around the coast and the forest shortage caused, firstly, the development of supplying strategies and, secondly, the creation of specifical orders in order to guarantee it. In that sense, Júcar and its tributary Cabriel played an important role in the trunks traffic coming from the mountains of Cuenca. Also, the surrounding countryside was primordial in the procedure. In this article we are going to analyse the methods in use in the Almoravid period and the circumstances of the trunks navigation on the river after the conquest. El abastecimiento de madera fue un aspecto fundament…

Discharge data series of Begura de Salma River (Mallorca, Spain): January 2015-October 2018

2020

Here we provide the data set obtained as described in detail in Estrany et al. (2020, doi:10.5194/nhess-2019-304); a brief description is presented below. A hydrometric gauging station is located where the Begura de Salma River enters Sant Llorenç des Cardassar, a village located in the northeastern part of Mallorca island (Spain). The station was built by the water authority in the 1970s. After years of abandonment, in 2015 the MEDhyCON Research Group installed within the gauge house a Hobo Water Level U20L-04, which measures the water stage by 1-minute readings, accumulating 15-minute average values. The station is located at the very beginning of the concrete channel that takes the river…

Influence of surface processes and initial topography on lateral fold growth and fold linkage mode

2015

Elongation of randomly distributed fold segments and their potential linkage are important for hydrocarbon exploration because it can greatly influence the morphology of the reservoir and both migration and accumulation of hydrocarbons in antiformal traps. Here we study the effects of surface processes and the presence of a topographic slope on the different linkage modes that can occur, and how these parameters affect the required horizontal offset for perturbations to link. The proposed numerical model represents a sedimentary cover detached over a much weaker basal decollement layer. The upper surface is modified by mass redistribution, which is achieved by a combination of fluvial and h…

A multidisciplinary approach to the evaluation of the mechanism that triggered the Cerda landslide (Sicily, Italy).

2005

Abstract The present paper describes a multidisciplinary approach to the evaluation of a seismically triggered landslide that occurred in the Cerda area (Italy) on September 6, 2002, about 1 h after an earthquake took place in the south Tyrrhenian Sea. The study was focused on an analysis of the role of the seismic input in triggering the landslide, in view of the evidence that no other mass movement was recorded in the adjacent areas despite geological and geomorphological spatial homogeneity. The studied area is located on a slope of the western flank of the Fiume Imera Settentrionale (Northern Sicily), which is made up of clayey–arenitic rocks. The slope inclines gently but is not unifor…

Field Testing of a Simple Flume (SMBF) for Flow Measurement in Open Channels

2008

In this paper the stage–discharge relationship of a new flume named SMBF (Samani, Magallanex, Baiamonte, Ferro), originally proposed by Samani and Magallanez and tested by Baiamonte and Ferro, for measuring flow discharge in open channels is reviewed. The flume is obtained inserting two semicylinders in a rectangular cross section. The results of some experimental runs carried out using horizontal flumes characterized by different values of the contraction ratio (ranging from 0.17 to 0.81) are used for determining the two coefficients of the power stage–discharge equation. The stage–discharge equation is tested using flow measurements carried out in the period between December 2004 and Marc…

CCambios seculares de la agradacion aluvial y de la meandrizacion en la Ribera Alta del Xuquer

1992

Dépôts carbonatés microbiens en domaine lacustre et fluviatile : fabriques et facteurs de contrôle

2020

The non-marine carbonates related to microbial activity display a large range of morphologies and compositions and accumulate in various settings (freshwater, alkaline, and saline lakes, fluvial environments, thermal and freshwater springs, …). The variety of non-marine microbial carbonates and their particularity led to propose numerous and complex terminologies and classifications, making their use complicated and restrictive for the interpretation of depositional settings. Mineralization of these carbonates results from the interaction between biotic factors (intrinsic) and environmental factors (extrinsic and external) at multi-scales. The first aim of this work was to characterize morp…