Search results for "Geomorphology"

Stima della potenza cinetica della precipitazione a partire da osservazioni disdrometriche di distribuzioni dimensionali delle gocce di pioggia

2011

Lo studio del distacco delle particelle di suolo operato dalla pioggia richiede la conoscenza delle caratteristiche erosive della precipitazione. Nella memoria, dopo aver richiamato i presupposti teorici della legge di Ulbrich e le espressioni della potenza cinetica da essa deducibili, viene presentata una verifica di applicabilita della suddetta distribuzione teorica sulla base delle distribuzioni dimensionali delle gocce di pioggia rilevate mediante un disdrometro ottico installato presso la sezione Idraulica del Dipartimento dei Sistemi Agro-Ambientali dell’Universita di Palermo. Viene proposta, infine, una verifica sperimentale dell’equazione di Wischmeier e Smith per il calcolo della p…

Environmental impact of magmatic fluorine emission in the Mt. Etna area

2007

-UniversitA degli Studi di Palermo, Italy -Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo - Unione Europea, Fondo Sociale Europeo

Integrated geomorphological mapping in the north-western sector of Agrigento (Italy)

2012

The geomorphological map is an essential tool to perform a proper urban planning in mountainous or hilly areas. In this paper a multidisciplinary approach to derive a 1:2000 geomorphological map is described. The proposed methodology consists of the integration between aerial photographs, acquired in 2003, and four datasets of Persistent Scatterer Interferometry (PSI) measures to update a pre-existing landslide inventory. The integrated data were used to achieve a validated geomorphological map by means of a geomorphological survey. The study area is located in southern Italy (Agrigento, Sicily). The city of Agrigento, included in the World Heritage List of UNESCO in 1997, is located on the…

Vertical movements of the Paris Basin (Triassic-Pleistocene): from 3D stratigraphic database to numerical models

2003

Pleistocene and Holocene aeolian sediments of different location and geological history: A new insight from rounding and frosting of quartz grains

2014

Abstract Rounding and frosting of quartz grains in aeolian sediments of the known stratigraphic position and unique geological setting was explored in Finnish, Estonian, Latvian, and Polish localities and in Fuerteventura Island. The aim of the study is to characterize the variability of the spatial pattern of rounding and frosting of quartz grains in the sandy (0.5–0.8 mm) fraction and to evaluate the factors influencing it. The relationships between rounded and non-abraded, as well as matt- and shiny-type quartz grains were calculated for 159 samples and evaluated against the aeolian subenvironment, substratum and presumed age of the locations. The obtained relations do not confirm meridi…

Emission standards versus immission standards for assessing the impact of urban drainage on ephemeral receiving water bodies

2010

In the past, emission standard indicators have been adopted by environmental regulation authorities in order to preserve the quality of a receiving water body. Such indicators are based on the frequency or magnitude of a polluted discharge that may be continuous or intermittent. In order to properly maintain the quality of receiving waters, the Water Framework Directive, following the basic ideas of British Urban Pollution Manual, has been established. The Directive has overtaken the emission-standard concept, substituting it with the stream-standard concept that fixes discharge limits for each polluting substance depending on the self-depurative characteristics of receiving waters. Stream-…

Application of time domain induced polarization to the mapping of lithotypes in a landfill site

2012

A direct current (DC) resistivity and time domain induced polarization (TDIP) survey was undertaken at a decommissioned landfill site situated in Hørløkke, Denmark, for the purpose of mapping the waste deposits and to discriminate important geological units that control the hydrology of the surrounding area. It is known that both waste deposits and clay have clear signatures in TDIP data, making it possible to enhance the resolution of geological structures compared to DC surveys alone. <br><br> Four DC/TDIP profiles were carried out crossing the landfill, and another seven profiles in the surroundings provide a sufficiently dense coverage of the entire area. The whole dataset w…

New luminescence ages reveal Early to Middle Weichselian deposits in central Latvia

2017

New optically stimulated luminescence (OSL) ages show that sandy deposits overlain by Late Weichselian subglacial till in central Latvia are of Early to Middle Weichselian age. The finer chronological resolution of unconsolidated sediment deposition in the Central Latvian Lowland (CLL) remains relatively unstudied, and here we provide a first characterisation of the deposits with respect to their age. Three OSL ages ranging between 84 ± 9 ka and 112 ± 11 ka suggest that the deposits studied in the CLL are of Early Weichselian age (MIS 5). We found no Middle Weichselian deposits in the CLL, and assume that any such younger sediments might have been eroded during the advance of the Zemgale Lo…

Areal extent and first U-Pb age of the Pre-Damaran Abbabis complex in the central Damara belt of South West Africa (Namibia)

1978

The Proterozoic Abbabis Complex emerges from beneath the metasediments of the Late Precambrian Damara Supergroup within mantled gneiss domes and anticlinoria over a wide area in the central granite zone of the Pan African Damara belt. U-Pb dating of composite-, size-, and non-magnetic fractions of metamict zircons from two samples of Abbabis granite-gneiss from the farm Abbabis yielded a concordia intercept age of 1925 −280 +330 Ma. It is speculated that the Abbabis basement rocks are continuous under the Damaran metasedimentary cover and may link up with the Franzfontein basement inlier of similar age. This conclusion supports the ensialic character of the northeastern branch of the Damara…

Receiving water quality assessment: comparison between simplified and detailed integrated urban modelling approaches

2010

Urban water quality management often requires use of numerical models allowing the evaluation of the cause–effect relationship between the input(s) (i.e. rainfall, pollutant concentrations on catchment surface and in sewer system) and the resulting water quality response. The conventional approach to the system (i.e. sewer system, wastewater treatment plant and receiving water body), considering each component separately, does not enable optimisation of the whole system. However, recent gains in understanding and modelling make it possible to represent the system as a whole and optimise its overall performance. Indeed, integrated urban drainage modelling is of growing interest for tools to …