RESUMEN

Climate change and excessive groundwater extraction are major contributors to rising groundwater salinization due to seawater intrusion in coastal aquifers. This study aims to define a wide-applicable approach in which hydrological balance, boundary conditions, and irrigation water demand, defined over time considering climate change predictions, can integrated into a numerical model of the groundwater system. The approach was tested in a selected coastal aquifer. The approach spans from the past, used to define steady or almost natural conditions for calibration purposes (1950-2000 in the test), to the future (2100), divided in decade steps. The water balance analysis is based on an inverse hydrogeological water balance approach. The future climate change predictions are used to assess variations in boundary conditions of the groundwater model concerning salinity and sea level, recharge, and inflow from upstream aquifers. The approach considers changes in agricultural activities, groundwater demand, and river stage. The regional model is generated using the MODFLOW code for the groundwater flow model and the SEAWAT code for the salt transport model. The test concerns the Metaponto coastal plain, in which a porous aquifer is at salinization risk due to seawater intrusion. In this way, different influences of climate change and human activities are combined to define a 3d view of groundwater depletion and salinization effects. Quantifying these potential effects or risks, adaptation scenarios with numerical assessments are outlined in this study.

RESUMEN

The data presented in this article are related to the research article described by "How can the role of leachate on nitrate concentration and groundwater quality be clarified? An approach for landfills in operation (Southern Italy)" (Cossu et al., 2018). The data set for this article contains chemical analyses of groundwater and leachate, isotope analysis of groundwater and leachate around a group of landfills located in the municipality of Conversano, close to Bari, the main town of the Apulia Region (Southern Italy). Groundwater samples were collected from eighteen wells. The hydrogeological and chemical study was used to define geochemical features, groundwater and leachate characteristics and to study their potential macroscopic mixing. The land use analysis highlighted quantity and type of used fertilizers permitting to compare these with groundwater in terms of isotopic signature.

RESUMEN

Where the unique natural water resource is groundwater, the attention and the susceptibility of local communities and authorities to groundwater quality degradation risks can be so high to determine relevant problems to waste management, especially for landfills in operation or to be realised. A multi-methodological approach was suggested with the purpose to clarify the role of landfill leakage on groundwater quality degradation. The selected study area (SSA) hosts some landfills in a narrow portion of a wide and deep coastal karstic aquifer, for these characteristics to be considered a case of high hydrogeological complexity and vulnerability. News concerning nitrate and secondly iron groundwater concentration anomalously high caused concern in the population and strong local opposition to landfills. The multi-methodological approach includes: the hydrogeological site characterization; the chemical study and the multi-isotope characterization of groundwater and leachate; the land use analysis and the estimation of nitrogen contributions deriving from fertilizers; the mineralogical study of groundwater suspended particles to define the role of natural soil substances. The hydrogeological site characterisation highlighted the local peculiarities of the aquifer. The chemical study was used to define geochemical features, groundwater and leachate characteristics and their macroscopic mixing. The environmental isotopes of hydrogen, carbon, nitrogen, and oxygen were used to investigate the groundwater origin, the most relevant geochemical reactions, the existence of groundwater-leachate mixing, and the sources of anthropogenic NO3-. The land use analysis highlighted quantity and type of used fertilizers permitting to compare these with groundwater in terms of isotopic signature. The mineralogical study demonstrated the role of suspend natural particles due the presence of terre rosse (red or residual soils) in groundwater. The approach confirmed that there are not the groundwater quality degradation effects of landfills, contributing to reassure population and institutions, simplifying the waste management.

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RESUMEN

The historical floods that have occurred since the seventeenth century were collected for a study area in southern Italy. Damages caused by floods, rainfall and the main anthropogenic modifications are discussed all together. The aim was to assess whether the frequency of floods is changing and, if so, whether these changes can be attributed to either rainfall and/or anthropogenic modifications. In 4 % of cases, mainly occurred in past centuries, floods damaged people. Hydraulic works, roads and private buildings were the more frequently damaged elements (25, 18 and 14 % of the cases, respectively). The annual variability of rainfall was discussed using an annual index. Short duration-high intensity rainfalls were characterized considering time series of annual maxima of 1, 3, 6, 12, and 24 h and daily rainfall. The rainfall shows a decreasing trend, in terms of both the annual maximum of short duration and the annual amount. The population has been progressively increasing since the sixteenth century, except during the years following the catastrophic 1908 earthquake. The rate of population growth has been very high since the second half of the twentieth century; the urbanized areas greatly increased, especially following the second half of the twentieth century. At the same time, the trend of damaging floods has been increasing, especially since the seventies. The analysis indicates that, despite a rainfall trend favourable towards a reduction in flood occurrence, floods damage has not decreased. This seems to be mainly the effect of mismanagement of land use modifications.

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