1,720,970 research outputs found
The role of hydrogeological monitoring in a multidisciplinary context for the preservation of the critical zone in the natural reserve of Castelporziano Estate
Full text linkCritical Zone (CZ) science has developed in recent years, involving different disciplines that vary depending on the specific research focus. This multidisciplinary approach highlights the relevance of the Underground component of the Critical Zone (UCZ) in regulating the water cycle, which can influence the complex equilibrium of the whole CZ. In this study, we analyze evolution during the time of different parameters, characterizing the saturated and unsaturated parts of the UCZ of the Castelporziano Estate, a natural reserve located in a coastal area close to Rome. The purposes of these activities are to monitor the potential depletion of groundwater resources and understand the recharge mechanism processes characterizing the aquifer in the framework of occurring climate changes, net of anthropogenic pressure. The long-term analyses of water table variations carried out over the last 25 years, allowed us to preliminarily identify four different ranges of the slope coefficient of the water table, characterizing different areas of the Estate. Specifically, the Northern, Central, and Coastal areas have shown a general depletion trend in piezometric levels, while in the Eastern area, a positive trend has been recognized. Additional long-term analysis of piezometric level variations allowed us to confirm the presence of the four recharge areas and compare annual recharge and water table levels to assess the relationship between the saturated UCZ and meteoric recharge in the identified areas. To evaluate the role of the unsaturated UCZ in recharge mechanisms, the water content in the first meter of soil has also been analyzed, showing different responses of outcropping sediments in capturing rainfall during different periods of the year and under different rainfall input conditions, highlighting the pivotal role of rainfall for the Castelporziano UCZ, both for deep recharge of the water table and for feeding the forest roots. Stable isotopes confirm that Castelporziano UCZ feeding is strongly dependent on local meteoric recharge, also highlighting that evaporation processes are active in a limited way. The obtained results assess that the monitoring of UCZ has a crucial role in the correct preservation of more complex environmental systems, which include groundwater resources and the coastal Mediterranean forest
Sustainability indicators of groundwater withdrawal in a heavily stressed system. The case of the Acque Albule basin (Rome, Italy)
Full text linkGroundwater sustainable yield is a concept widely treated theoretically in the literature. Moving from theoretical concepts to the definition of practical measures for groundwater management is not easy due to site-specific characteristics of the system. This study is aimed at identifying which factors influence the sustainable yield of the plain of Tivoli (Central Italy), where thermal springs with considerable flow (over 2 m3/s) emerge (or rather emerged) and supply a thermal plant. In the same plain, another profitable economic activity concerns the extraction of travertine; it caused a progressive decline in groundwater levels and in the discharge of the thermal springs. The hydrogeological history of the site and the data available in the literature and in new focused surveys are encapsulated in a simple flow model addressed to compare the pre- with the under-development conditions. The withdrawal of groundwater from the quarry area determined a significant impact on the water balance of the system. An increase in inflow from surrounding aquifers and a decrease in storage and in natural discharge of the travertine aquifer result in under-development conditions. Residual discharges towards the springs and river are very sensitive to the pumping flow rate of quarries, according to an inverse linear relationship; this hydrogeological feature may be adopted as an indicator of the sustainability of groundwater withdrawals from the plain. The residual discharge is most affected by the position of the pumping center in the groundwater flow net and its distance from boundaries to be captured, as well as on the depth and extent of the quarries. This lays the basis for developing sustainable management models of groundwater considering the economic and environmental aspects of the issue
Use of an integrated methodological approach to assess contaminant fate and transport in a coastal aquifer
No full textValidation of a density dependent groundwater transport model using mass recovery rate
No full textIn this short note is described the validation process of a density dependent groundwater transport model, previously implemented and published, using the mass recovery rate of dissolved Total Petroleum Hydrocarbons and Chloride from 67 pumping wells in a polluted site. A good fit between observed and calculated values was recorded, supporting the feasibility of flow and transport models validation in complex polluted sites where pump & treat remediation are applied and management strategies need to be rapid and robus
Updating the water budget of the Gran Sasso carbonate fractured/karstified aquifer (Central Italy) for a sustainable management of groundwater resources
No full textKarst aquifers are fundamental in the water supply of European countries, where outcrops of carbonate rocks are very common, providing abundant groundwater resources. The Gran Sasso karst aquifer, selected as representative study area for Italy in the EU-funded KARMA project, is characterized by both high percentage of withdrawals for drinking purposes and significant interaction between groundwater and underground works. The recharge evaluation of the aquifer has been carried out considering the 2001–2020 monitoring period, comparing three different methods: the Turc and APLIS methods, on annual scale, and the Thornthwaite method, on monthly scale, territorially distributed by 100 x 100 m cells on GIS basis. The total recharge considers not only rainfall but also the contribution of snow melting on infiltration. The results show similar mean recharge values in 2001–2020 for all methods, corresponding to 19.9, 18.5, and 19.4 m3/s, respectively, from Turc, Thornthwaite, and APLIS methods. A significant contribution to recharge from snowmelt has been confirmed (3.2 m3/s included in the above-mentioned values). These values can be considered reliable with respect to real discharge of the regional aquifer. The obtained results can be used to provide updated information to the drinking water companies for a suitable management of the available resource
Groundwater recharge distribution due to snow cover in shortage conditions (2019–22) on the Gran Sasso carbonate aquifer (Central Italy)
Full text linkAquifer recharge by the snowpack is relevant to be assessed to evaluate groundwater availability in mountainous karst regions. The recharge due to snowpack in the Gran Sasso aquifer has previously been estimated through an empirical approach using elevation gradients. To validate and quantify the coverage and persistence of the snowpack over time through an objective method, satellite images have been analysed. The Campo Imperatore plain, the endorheic basin acting as a preferential recharge area of the aquifer, plays an important role, both for the snow cover and also for the infiltration and recharge of springs. The identification of recharge areas has been validated by the stable isotope approach with the assessment of computed isotope recharge elevation based on the values and oscillations of the delta O-18 isotope recorded at the springs. The main findings confirm the high infiltration rate of Campo Imperatore plain and its direct influence on snow contribution to aquifer recharge. The extension of snow coverage out of this plain has a minor influence to recharge, highlighting that the main drivers for infiltration rate are fractured networks and karstic forms more than snow coverage on carbonate outcrops
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
