Search results for "Sediment"

Caratterizzazione geomorfologica e sedimentaria di un margine continentale sottoalimentato: analisi sismo-acustica del sistema piattaforma-scarpata d…

2014

Site effects assessment through historical and instrumental data integration

2006

ABSTRACT This work illustrates the historical data contribution to the analysis of the microtremor survey results carried out in May 2003 in the city of Palermo by the Istituto Nazionale di Geofisica e Vulcanologia and the Dipartimento di Geologia e Geodesia – University of Palermo. The microtremor survey has been carried out within the project SESAME (Site EffectS assessment using AMbient Excitations) funded by the European Commission, devoted to test the effectiveness of the seismic noise, and in particular of Nakamura technique, in the site effects assessment. The Nakamura technique singles out zones characterized by a near-surface geology suitable to produce site effects, by exploiting …

Predicting soil loss on moderate slopes using an empirical model for sediment concentration

2011

Summary The objective of this investigation was to estimate event soil loss per unit area from bare plots in central and southern Italy using an empirical model for sediment concentration. The analysis was developed using data collected on bare plots differing in length (11–44 m) and slope (10–26%) at three Italian stations (Masse, Umbria; Caratozzolo, Calabria; Sparacia, Sicily). At first, an analysis was carried out, using the experimental data collected at Sparacia, to establish a relationship between sediment concentration and hydrological variables, such as runoff, rainfall amount and single storm erosion index. Then, an empirical model to estimate plot soil loss as a function of rainf…

Modelling sediment delivery processes by a stream tube approach

1999

Abstract The sediment delivery processes due to the travel along a hydraulic path having an uniform slope and to the concave shape of the path are modelled. In particular, using a power equation for modelling the slope profile and RUSLE with two different expressions of the topographic factors, a criterion to define the erosion active slope length, i.e. the slope length in which no deposition processes occur, is initially proposed. Then, the RUSLE equation is adapted to concave profiles by a correction factor of the topographic factors depending on slope curvature. Finally, the deduced relationships (equations (19) and (27)) for correcting the topographic factors for a concave slope are exp…

Soft-sediment deformation structures (SSDS) in Pleistocene calcarenites of Favignana island (Sicily, Italy)

2013

Testing assumptions and procedures to empirically predict bare plot soil loss in a Mediterranean environment

2014

Empirical prediction of soil erosion has both scientific and practical importance. This investigation tested USLE and USLE-based procedures to predict bare plot soil loss at the Sparacia area, in Sicily. Event soil loss per unit area, Ae, did not vary appreciably with plot length, λ, because the decrease in runoff with λ was offset by an increase in sediment concentration. Slope steepness, s, had a positive effective on Ae, and this result was associated with a runoff coefficient that did not vary appreciably with s and a sediment concentration generally increasing with s. Plot steepness did not have a statistically detectable effect on the calculations of the soil erodibility factor of bot…

Modelling soil carbon fate under erosion process in vineyard

2017

Soil erosion processes in vineyards beyond water runoff and sediment transport have a strong effect on soil organic carbon loss (SOC) and redistribution along the slope. The variation of SOC across the landscape determines a difference in soil fertility and vine productivity. The aim of this research was to study erosion of a Mediterranean vineyard, develop an approach to estimate the SOC loss, correlate the vines vigor with sediment and carbon erosion. The study was carried out in a Sicilian (Italy) vineyard, planted in 2011. Along the slope, six pedons were studied by digging 6 pits up to 60cm depth. Soil was sampled in each pedon every 10cm and SOC was analyzed. Soil erosion, detachment …

The Use of Analysis of Weather Types to Complete the Studies of Soil Erosion in Vineyards and Abandoned Areas

2019

This presentation aims to quantify water and soil losses due to rainfall and specific soil management practices in combination with an analysis of which kind of weather type and rainfall event is able to cause specific surface flows and soil loss rates. As study area, we used the specific case of the sloping vineyards of the Montes de Malaga (South Spain). Two different plots were used: one cultivated area and poorly managed abandoned one. The in situ measures were conducted using sediment collectors to estimate sediment yield (g m−1) and surface runoff (L m−1) and an analysis of the weather conditions during each rainfall event using different meteorological sources. The weather types that…

The capability of Rare Earth Elements geochemistry to interpret complex archaeological stratigraphy

2019

Abstract In this study rare earth elements (REE) signatures (REE ratios, cerium and europium anomalies) are applied to a complex soil stratigraphic sequence from the site of Konso, Ethiopia, with the aim of determining whether REE can distinguish the strata observed in the field. Forty soil samples were taken from a depositional sequence that includes overlapping human induced and ‘natural’ erosional and depositional processes. The samples were analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to determine trace elements and REE, with concentrations of major elements determined using X-ray fluorescence (XRF). Cluster Analyses (CA) were used to observe differences between str…

Effects of length and application rate of rice straw mulch on surface runoff and soil loss under laboratory simulated rainfall

2021

Abstract Forest land affected by deforestation yields high soil and water losses. Suitable management practices need to be found that can reduce these losses and achieve ecological and hydrological sustainability of the deforested areas. Mulch has been found to be effective in reducing soil losses; straw mulch is easy to apply, contributes soil organic matter, and is efficient since the day of application. However, the complex effects of rice straw mulch with different application rates and lengths on surface runoff and soil loss have not been clarified in depth. The current paper evaluates the efficiency of rice straw mulch in reducing the hydrological response of a silty clay loam soil un…