1,721,034 research outputs found
Characterizing the recharge of fractured aquifers: a case study in a flysch rock-mass of the northern Apennines (Italy)
No full text12 springs from the northern Apennines of Italy were studied by means of a comprehensive
hydrogeological investigation to unravel recharge processes taking place in a highly fractured
slab of flysch rock hosting the corresponding aquifers. Several campaigns were carried out
during the period 2005–2008 to gather springs’ discharge together with electrical conductivity
and temperature data. Water samples were collected and allowed the determination of the
major ions (Ca2+, Mg2+, Na+
, K+, SO42−, HCO3
−, Cl−
) and the isotopic content (δ18O).
Additionally, groundwater discharge from 3 selected springs was measured continuously using
pressure-transducers. Over the same period, reference δ18O values for rainfall and snow-melt
water were collected monthly by a rain-gauge. Results highlighted an aquifer-like behavior of
this slab of flysch rock. The springs are characterized by a Ca–HCO3 hydro-facies and an
increase of groundwater mineralization has been noticed moving toward the base of the slab;
the mean discharges are between 0.3 and 0.7 l·s−1 and suffered a marked variability during the
year; the total maximum yield is about 155,000 m3 while the total discharge volume is around
320,000 m3·y−1. By processing the δ18O isotope values from springs (mean annual values
ranged from −9.67 and −10.42‰) and by combining them with rainfalls datasets, results show
that the main aliquot of recharge occurs in the winter—spring months and it is principally
related to the solid precipitations (snow-melt)
Hydrogeological processes in clay-rich slopes: further insights from geochemical modelling
No full textSlope instability phenomena frequently develop within clayshales. Despite rise in pore-water pressures is one of the main factors
for landslides triggering, hydrogeological processes taking place in slopes composed by clay-shales are far to be fully understood. That is due to the high heterogeneity of the materials and to the presence of fissures and fractures that can: (1) allow the presence of perched aquifers, (2) lead to the hydrogeological parting between stable and
unstable sectors of the slope, (3) permit the development of preferential flow-paths. Moreover, (4) thrusts and faults can drive
groundwater flow from far away, adding further complexity to the definition of the hydrogeological boundaries of the studied systems. Hydrochemistry is a powerful tool, which helps to unravel the abovementioned points. The purpose of this short note is to test the usefulness of geochemical modelling in identifying groundwater dynamics and interactions between host-rocks and groundwater. Both thermodynamic and kinetic approaches have been used in an earthflow located in the northern Apennines of Italy
Suscettibilità per frane superficiali (shallow traslational slides e soil slips). Quadro Conoscitivo - Sistema ambientale – Allegato 06 - La Geologia e la Geomorfologia e Tavola 4 – Carta di suscettibilità per frane superficiali
No full textIl lavoro sintetizza metodi e risultati della mappatura della suscettibilità da frane superficiali dell'area collinare della Provincia di Reggio Emilia, effettuata per mezzo di analisi multivariate
Modelling groundwater and slope processes in a calcarenitic slab: The case of San Leo (northern Apennines)
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Analisi della predisposizione al manifestarsi di sorgenti in area appenninica: un approccio statistico applicato all’area del Monte Modino (Provincia di Modena)
No full textIl lavoro,centrato sull’applicazione di codici di calcolo statisticiin ambiente Arc-GIS già utilizzati nel campo dellaricerca geomineraria, intergrati con l’analisi dei complessiidrogeologici, permette l’individuazione delle zonepotenzialmente idonee al reperimento ed eventuale captazionedella risorsa. Il tipo di informazione ottenuta,integrata ad una carta dei complessi idrogeologici, èutile per la pianificazione dello sfruttamento e per latutela della risorsa idrica
Modellazione numerica dei meccanismi di riattivazione di grandi frane per scivolamento di terra: l’esempio della frana di Tolara, Appennino settentrionale
No full textThe time and space evolution of large earth slides in weak and complex rockmasses, that characterize thenorthern Apennines, is depending on geological setting and past climate. At the present the reactivation of theselandslides are due to mainly to hydrogeological and geotechnical features. This paper describes the hydrogeological andgeotechnical features of these landslides and the reactivations mechanism using coupled 2D hydrogeological numericalmodel and limit equilibrium analysis (Geoslope, 2004). The case study is the Tolara landslide (Modena Apennines) thatresumed activity in 2002. In this landslide some hydrogeological and geotechnical data have been collected from 2003 todate
Hydro-mechanical features of landslide reactivation in weak clayey rocks
No full textIn the northern Apennines, four representativelarge and deep seated landslides affecting weak rockmasses have been studied before, during and after reactivationevents. Semi-continuous and continuous monitoringin the 2004–2006 period included the dormancy, reactivationand suspension phases, allowing some comments tobe put forward as regards the hydro-mechanical conditionsthat drive the reactivations. The data have highlighted theinteractions between groundwater and displacement ratesin different sections of the slope
Hydrogeological investigation of Pietra di Bismantova slab and surrounding slope deposits (northern Apennines, Italy)
No full textThe recent application of hydrochemistry to unstable slopes reveals the contribution of this technique to better understand hydrological processes, water rock interaction and to outline groundwater flow paths. The aim of this short note is to present results from two years of semi-continuous monitoring (discharge, EC, temperature) of two springs (Eremo and F. Cornia spring) flowing along the SE slope of Bismantova fractured slab, in the stable and unstable portion of the slope respectively. Both springs follow the precipitation pattern with the increase of discharge and decrease of temperature as consequence of rainfall recharge; moreover the increase of EC seems to suggest interaction beetween groundwater and mineral phases hosted along fractures of the slab. Using chemical results a first inverse modeling with PHREEQC have been performed in order to identify the interaction between water infiltrating in host-rock and mineral phases, as well to reconstruct geochemical evolution of groundwater from the upward stable portion to the downward unstable portion of the slope
Weight of Evidence and Artificial Neural Networks for potential groundwater springs mapping: an application in Mt. Modino area (Northern Apennines, Italy)
No full textLocations of potential groundwater springs were mapped in an area of 68 km2 in the Northern Apennines of Italy based on Weight of Evidence (WofE) and Radial Basis Function Link Net (RBFLN). A map of more than 200 springs and maps of five causal factors were uploaded to ArcGIS with Spatial Data Modelling extensions. The WofE and RBFLN potential groundwater spring maps had similar prediction rates, allowing about 50% of the training and validation springs to be predicted in about 15 to 20% of the study area. The two maps were merged using a heuristic combination matrix in order to produce two hybrid maps: one representing susceptible areas in both the WofE and RBFLN maps (type A), while the other representing susceptible areas at least in one of the two maps (type B). For small cumulated areas, the success rate of both hybrid maps was higher than that of the parent maps, while for large cumulated areas, only the type B hybrid map performed similarly to the parent maps. This conclusion suggests different applications of these maps to water management purposes
Hydrogeological characterization of peculiar Apenninic springs
Full text linkIn the northern Apennines of Italy, springs are quite widespread over the slopes. Due to the outcropping of low-permeability geologic units, they are generally characterized by low-yield capacities and high discharge variability during the hydrologic year. In addition, low-flow periods (discharge lower than 1 Ls-1) reflect rainfall and snowmelt distribution and generally occur in summer seasons. These features strongly condition the management for water-supply purposes, making it particularly complex. The "Mulino delle Vene" springs (420 m a.s.l., Reggio Emilia Province, Italy) are one of the largest in the Apennines for mean annual discharge and dynamic storage and are considered as the main water resource in the area. They flow out from several joints and fractures at the bottom of an arenite rock mass outcrop in the vicinity of the Tresinaro River. To date, these springs have not yet been exploited, as the knowledge about the hydrogeological characteristics of the aquifer and their hydrological behaviour is not fully achieved. This study aims to describe the recharge processes and to define the hydrogeological boundaries of the aquifer. It is based on river and spring discharge monitoring and groundwater balance assessment carried out during the period 2012–2013. Results confirm the effectiveness of the approach, as it allowed the total aliquot of discharge of the springs to be assessed. Moreover, by comparing the observed discharge volume with the one calculated with the groundwater balance, the aquifer has been identified with the arenite slab (mean altitude of 580 m a.s.l.), extended about 5.5 km2 and located 1 km west of the monitored springs
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