Hydraulic conductivity estimation using low-flow purging data elaboration in contaminated sites

Hydrogeological characterization is required when investigating contaminated sites, and hydraulic conductivity is an important parameter that needs to be estimated. Before groundwater sampling, well water level values are measured during low-flow purging to check the correct driving of the activity. However, these data are generally considered only as an indicator of an adequate well purging. In this paper, water levels and purging flow rates were considered to estimate hydraulic conductivity values in an alluvial aquifer, and the obtained results were compared with traditional hydraulic conductivity test results carried on in the same area. To test the applicability of this method, data coming from 59 wells located in the alluvial aquifer of Malagrotta waste disposal site, a large area of 160 ha near Rome, were analyzed and processed. Hydraulic conductivity values were estimated by applying the Dupuit's hypothesis for steady-state radial flow in an unconfined aquifer, as these are the hydraulic conditions in pumping wells for remediation purposes. This study aims to show that low-flow purging procedures in monitoring wells-carried out before sampling for groundwater characterization-represent an easy and inexpensive method for soil hydraulic conductivity estimation with good feasibility, if correctly carried on

Karst spring recharge areas and discharge relationship by oxygen-18 and deuterium isotopes analyses. A case study in southern latium region, Italy

Karst aquifer recharge areas are usually difficult to identify because of the complexity of these aquifers' characteristics. On the other hand, their identification is very important in the aim of protecting the groundwater resources that these aquifers host. Regarding this topic, this paper presents an approach aimed at identifying karst aquifer recharge areas by the application of oxygen-18 and deuterium isotopes composition of groundwater coupled with hydrological features. Oxygen-18 and deuterium isotope composition of Capodacqua di Spigno Spring, in the South of the Latium Region, has been applied with rainfall and discharge values related to the feeding aquifer of this spring. As δ18O and δ2H values of groundwater samples are natural tracers of the recharge area's elevation, we propose a model, based on the distribution of the basin surfaces involved as recharge areas, in relation to elevations. The model estimates, for any discharge value, the percentage of the topographic area involved in the aquifer recharge. The setting up of this simulated distribution is supported by a Weibull cumulative probability function. The results show that the measured discharges increase as larger areas with lower elevations are involved in the recharge process

La rete strumentale di Gioia Tauro per lo studio del moto sismico

SIGLEITItal

Effects of packaging techniques, freezing temperature and storage time on beef shelf life

Modified atmosphere packaging (MAP) is well-known as a method to extend the shelf life of a variety of foods including fresh red meat (Luño et al., 2000). Atmospheres combine oxygen (O2), carbon dioxide (CO2), and nitrogen (N2) to maintain the quality of fresh red meat. CO2 is known for its inhibitory effect on microbial growth (Silliker and Wolfe, 1980); nevertheless atmospheres with high levels of CO2 (low O2) can cause meat discoloration (Silliker et al., 1977). In the present research physical characteristics and oxidative stability have been checked on Maremmana crossbreed Longissimus thoracis muscle after packaging under vacuum and in modified atmosphere and then storage at three temperatures for three different times

Effects of climate change on groundwater feeding the Mazzoccolo and Capodacqua di Spigno Springs (Central Italy): First quantitative assestments

In Italy, the summer of 2017 was characterized by serious problems related to the water crisis that affected the entire national territory. The Municipality of Formia, as well as many other territories in the Latina Province, had to face heavy rationing of the water supply during the summer, with consequent inconvenience for the population. In this paper, two spring and their relative aquifers were studied: the Mazzoccolo Spring and the Capodacqua di Spigno Spring. For both aquifers, a hydrogeological water balance was calculated based on the collection of thermo-pluviometric data on an appropriate time series, at the meteorological stations present within and around the study area. The main goal was to establish, in the context of current climate change, the potential of the aquifers that feed these water resources. For the calculation of the active recharge, in order to have an estimation value of the supply volumes, data referred to four meteorological stations in the study area for a time series of 40 years (1959-1999) were collected and processed. The stations considered are the following: Gaeta, Itri, Esperia and SS Cosma e Damiano pluviometric stations. Each basin has been divided into finished square elements (FSE), with a size of 10000 m2, using a GIS software. The value of the effective infiltration to assign to each cell is a function of the annual rainfall value and the annual evapotranspiration value, both referred to the cell itself. The sum of all the values referred to each cell of the grid, provided the estimation of the aquifer annual average recharge as average annual volume. The same procedure was used for maximum, minimum and medium values of the rainfall on the time series considered and for the single annual rainfall value of 2017. Results confirmed the extraordinary nature of the drought event that occurred during the recharge period of 2017, showing a huge decrease of the average available water volume. In conclusion, for the Mazzoccolo and Capodacqua di Spigno Springs, future interventions are going to be planned for the catchment optimization in order to overcome any future possible water crises, even considering the permanent reserves, without compromising their medium and long term availability and their quality

Recent drought effects on bracciano lake water availability

Drought events are currently increasing in frequency and intensity all over the world as effect of climate change. One of the most related environmental issue is water resource scarcity, which is now becoming an emergency also for several industrialized countries in the Mediterranean area. In the summer of 2017, all Italian territory suffered from an extreme drought event that caused huge depletions of both groundwater and surface water availability. In particular, Bracciano Lake, which is one of the largest surface water resource of Central Italy, showed the largest water level drop in 50 years of observation, with a critic impact on the Lake’s ecological system. This event highlighted once again the key-role of water shortage analysis, whose main goal is studying the relationship between rainfall deficit and water resources availability. Moreover, their long-term trends need to be studied in order to find sustainable solutions for the increasing water demand of the population. In particular, in this paper, data related to time series of about 60 years have been analyzed with the aim of finding highly significant relationships between Bracciano Lake level drops at different time scales, and the SPI (Standard Precipitation Index), which is currently the most widely used hydrological drought indicator. This study aims to demonstrate that specific drought indices may be useful tools for water system management

Recent drought effects on bracciano lake water availability

Drought events are currently increasing in frequency and intensity all over the world as effect of climate change. One of the most related environmental issue is water resource scarcity, which is now becoming an emergency also for several industrialized countries in the Mediterranean area. In the summer of 2017, all Italian territory suffered from an extreme drought event that caused huge depletions of both groundwater and surface water availability. In particular, Bracciano Lake, which is one of the largest surface water resource of Central Italy, showed the largest water level drop in 50 years of observation, with a critic impact on the Lake’s ecological system. This event highlighted once again the key-role of water shortage analysis, whose main goal is studying the relationship between rainfall deficit and water resources availability. Moreover, their long-term trends need to be studied in order to find sustainable solutions for the increasing water demand of the population. In particular, in this paper, data related to time series of about 60 years have been analyzed with the aim of finding highly significant relationships between Bracciano Lake level drops at different time scales, and the SPI (Standard Precipitation Index), which is currently the most widely used hydrological drought indicator. This study aims to demonstrate that specific drought indices may be useful tools for water system management