Geological and Hydrogeological Characterization of Springs in a DSGSD Context (Rodoretto Valley – NW Italian Alps)

As continuous groundwater monitoring in the upper sector of Rodoretto Valley (Germanasca Valley, Italian Western Alps) is hampered by logistical problem of data collection during winter and spring months, the only tools currently available to derive hydrogeological information are non-continuous and non-long-term dataset of spring discharge (Q), temperature (T) and electrical conductivity (EC). In order to quantity aquifer groundwater reserve, available Q dataset of a small mountain spring (Spring 1 CB) was investigated by applying the analytical solutions developed by Boussinesq (J Math Pure Appl 10:5–78, 1904) and Maillet (Essais dı’hydraulique souterraine et fluviale, vol 1. Herman et Cie, Paris, 1905); T and EC datasets were also used to provide qualitative information about the nature of the aquifer that supplies the spring. The outcomes of the elaborations highlighted the limits of applicability of these methods in the presence of a non-continuous Q dataset: both Boussinesq (J Math Pure Appl 10:5–78, 1904) and Maillet (Essais dı’hydraulique souterraine et fluviale, vol 1. Herman et Cie, Paris, 1905) estimated that discharge values as a function of recession time were found to be consistently lower than the available discharge ones and the estimated groundwater volumes stored over time above the spring level turned out to be underestimated. Continuous (hourly value) and long-term Q, EC and T values are, therefore, needful to correctly quantify and to make a proper management of groundwater resources in mountain areas

Evoluzione geomorfologica recente della media-bassa valle del fiume Tronto (Marche meridionali)

The geomorphological dynamics is an important indicator for understanding processes of river erosion and sediment transport useful to plan appropriate remedial works along the rivers, so as not to modify the fragile equilibrium of the river itself. The present study aims at improve the knowledge on the geomorphological evolution of the Tronto river between the river’s mouth and the town of Ascoli Piceno through the analysis of historical maps and aerial photos covering different time spans. The retrieval of historical maps has allowed the reconstruction of the geomorphological evolution of the river bed and of the intervention aimed at river banks protection or, sometimes, for agricultural and industrial use. The interventions along the river beds began around the early 1900s (following the disastrous events of 1897 and 1898), resulting in a strong reduction of the floodplain width, from about 330 up to 210 meters and a rectification of the same with the construction of embankments up to 6 meters above the thalweg; these interventions were more intense at the mouth. The mismanagement of the terminal reach, among other things, after the interventions started in 1978 with the overall reduction in the flow section of the river, will favor the expansion of the flow during the 1992 flood event. The analysis, carried out in a GIS environment, evidenced as the interventions made along the river, have progressively modified almost all of the river reach for a length of over 20 km, reducing the typical cross section of about 50%

Co-seismic and post-seismic changes in groundwater discharge: First results from the epicentral region of the Central Italy earthquake 2016

Short and mid-term effects of earthquakes on groundwater flow were documented in several studies. The hydrogeological response of groundwater flow systems to earthquakes is very complex and due to significant changes in permeability. Such hydrologic changes may occur even at great distances from the epicentre and their magnitude may be related to the proximity to the earthquake focus. Central Italy has been hit by several large earthquakes since August 2016. With reference to the carbonate aquifers located in the epicentral region, the following short term effects were observed: a significant increase of the spring discharges and the disappearance of several perched springs. The deep-seated fault movements and fluid redistribution may cause water-level fluctuations as well as changes in groundwater discharge and composition. This study describes a preliminary characterization of such processes. © Società Geologica Italiana, Roma 2019

The effects of in-stream gravel mining on river incision: an example from Central Adriatic Italy

This study shows the consequences of intense human activities carried out along river beds in Central Adriatic Italy during the twentieth century. There have been many attempts to quantitatively correlate river incision with sediment reduction following the construction of dams, but few approaches have taken into account the effects of gravel quarrying or river bed adjustement. Using topographic, hydraulic and sedimentary data from several rivers of central and northern Italy an empirical relation was formulated to establish a relationship between fluvial erosion capacity consequent to quarrying and the amount of fluvial incision. The results are promising, highlighting the need for further researc

Density Functional Theory modelling of protection agents for carbonate stones: case study of oxalate and oxamate inorganic salts

Sulphur and nitrogen oxide pollutants cause acid rain that can eventually lead to the dissolution of calcite in marble and limestones. Calcium oxalate is an inorganic protective agent, which is obtained by treatment with ammonium oxalate. The functionalization of oxalic acid to give monoesters and monoamides (oxamates) allows tailoring the solubility of the relevant ammonium and calcium salts. In this context, theoretical calculations carried out at the Density Functional Theory (DFT) level were exploited to investigate the capability of oxalate, methyloxalate, phenyloxalate, oxamate, methyloxamate, and phenyloxamate to interact with the calcium carbonate lattice. An in-depth validation based on the structural data showed that DFT calculations with the PBE0 functional along with a single or triple-zeta def2 basis set allow understanding the different reactivity of the oxalate and oxamate derivatives and their efficiency in interacting with stones containing calcium carbonate, such as Carrara marble and biomicritic limestones

Ammonium monoethyloxalate (AmEtOx): a new agent for the conservation of carbonate stone substrates

The ammonium salt of monoethyloxalate (AmEtOx) was investigated as a novel precursor for the conservation of carbonate stone substrates, such as biomicritic limestone and marble. Full characterization of treated and untreated authentic stone samples was carried out by means of SEM, X-ray powder diffraction, synchrotron tts-mXRD measurements, mercury intrusion porosimetry, determination of water transport properties, and pull-off tests. The improved solubility (1.49 M, 20.1% w/w) of AmEtOx as compared to that of ammonium oxalate (AmOx; 0.4 M, 5% w/w) results in the formation of microcrystalline phases 30–50 and 200–500 mm thick of calcium oxalate mono-(whewellite) or dihydrate (weddellite), on marble and biomicrite samples, respectively, after treatment with AmEtOx 5% and 12% w/w aqueous solutions. As a result, a reduction in the porosity of the stone samples and an enhancement of their cohesion are observed. DFT calculations, carried out to investigate the hydrolysis reaction leading from AmEtOx to AmOx, showed that the localization of the Lowest Unoccupied Molecular Orbital (LUMO) and the natural charge distribution account nicely for the tendency to hydrolyse observed experimentally, eventually leading to the formation of whewellite and weddellite on the stone surface