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Hydraulic conductivity is a basic property of rocks and soil, and its estimation varies as a function of the scale and purpose of the study. This work combines geomorphological analysis, geological data, and groundwater investigations from literature to assess large-scale anisotropies in hydraulic conductivity in the North China Plain. The study area encompasses 144,000 km2 and represents the most important groundwater system of China, affected in the last 40 years by severe groundwater depletion, pollution, and subsidence. The investigation area is at the center of a massive groundwater project, the South to North Water Transfer Project, which was designed and implemented to alleviate water scarcity and facilitate environmental recovery. A conceptual model based on geomorphological evidence, supported by borehole logs, and satellite image analysis is used to assess the hydraulic conductivity anisotropies at the regional scale. The model divides the alluvial plain into four geomorphological zones with similar hydraulic conductivity characteristics. Along the general groundwater flow direction, upstream hydraulic conductivity is assumed isotropic but strong anisotropies are deduced downstream. An accurate hydraulic conductivity assessment is essential to improve quantitative studies of contaminant transport, artificial aquifer recharge, and land subsidence in the North China Plain and elsewhere.

Groundwater is a primary water source which supplies more than 2 billion people. The increasing population and urbanization of rural areas stresses and depletes the groundwater systems, reducing the groundwater quality. Among the emerging contaminants, microplastics (MPs) are becoming an important issue due to their persistency in the environment. Seepage through the pores and fractures as well as the interaction with colloidal aggregates can partially affect the MPs dynamics in the subsoil, making the detection of the MPs in the groundwater systems challenging. Based on literature, a critical analysis of MPs in groundwater is presented from a hydrogeological point of view. In addition, a review of the MPs data potentially affecting the groundwater systems are included. MPs in groundwater may have several sources, including the atmosphere, the interaction with surface water bodies, urban infrastructures, or agricultural soils. The characterization of both the groundwater dynamics and the heterogeneity of MPs is suggested, proposing a new framework named “Hydrogeoplastic Model”. MPs detection methods aimed at characterizing the smaller fragments are necessary to clarify the fate of these contaminants in the aquifers. This review also aims to support future research on MP contamination in groundwater, pointing out the current knowledge and the future risks which could affect groundwater resources worldwide.

Groundwater interactions with surface water and sewers in an urban setting are complex, and classic hydrogeological approaches must be combined with anthropogenic elements to characterize them. The level of detail needed to understand these interactions is illustrated by the analysis of an urban subcatchment in the megacity of Shenzhen in southern China that has had a drastic urban expansion in the last 40 years. The study area is characterized by the Yanshanian granite that is widespread across southern-eastern China. The urban setting is studied using multitemporal analysis of satellite images, borehole investigations and field surveys. Given the local hydrostratigraphy, a conceptual model was developed to identify the physical and anthropogenic factors that regulate the urban groundwater system. Based on the conceptual model and the data collected from the field or compiled from the literature, the average annual effective recharge is estimated to be 290 mm/year, after the urbanization process. From rural to urban conditions, it is estimated that the effective recharge increased by 170% and sewers intercept at least 23% of the effective recharge. Groundwater captured by sewers reduces river flows and increases the required capacity and costs for waste water treatment plants.

Study area: Shenzhen Megacity, southern China. Study focus: “Sponge City” is a Chinese concept aimed to mitigate flood risk, tackle chronic water scarcity, and improve the urban environment. It consists of a combination of new storage and infiltration facilities distributed on a large scale. The concept is similar to strategies and developments already adopted in the Western world. In this paper, new constraints on the interactions between the sponge facilities, the landscape and the subsoil are identified for a hilly, sub-tropic terrain. New hydrological insights for the region: Using a geomorphological zonation at the catchment scale, a conceptual model is proposed for southern China to identify areas where groundwater infiltration and storage is feasible. The proposed model is applied to Shenzhen, a megacity in southern China chosen as a pilot site for Sponge City, with 24 project areas already identified. Our zonation approach suggests that project areas on the coastal plain and reclaimed land will only work with above-ground storage, while there is significant potential to enhance many of the other pilot areas with infiltration facilities. The conceptual model improves the Sponge City approach aimed at increasing the managed annual runoff; it also mitigates the waterlogging risk. At the same time, the proposed conceptual model has moderate costs and makes possible the application of the Sponge City concept in other urban areas of southern China. Keywords: Conceptual model, Flood mitigation, Groundwater, Urban planning, Urban waterlogging, Wet climate

Urban aquifers represent an undeveloped resource and utilization is also arising as a method to improve storm water management. In dry climate, these aquifers are an alternative water supply source and in tropical climate can mitigate waterlogging and floods. However, sources and pathways of urban groundwater are more numerous and complex than those in rural environments. Furthermore, climate change and more frequent and intense climate extremes increase the variability in precipitation, soil moisture, and surface water. Therefore, a long-term effective urban water management is imperative.This study investigates the groundwater in Shenzhen, a major financial and high-tech center in southern China, along the left side of the Zhujiang Estuary (Pearl River Delta). Shenzhen has a population of about 14 million permanent residents and currently has a total water consumption of 2 billion m3 per annum. Previous research has investigated the hydrogeological setting and groundwater budgets via numerical flow simulations under steady-state conditions. In the present research, a MODFLOW transient model has been constructed to estimate the groundwater budgets in Shenzhen in response to projected climate change.Model conditions are varied, considering the typical Representative Concentration Pathway (RCP) scenarios (RCP 2.6, RCP4.5, RCP 6.0 and RCP 8.5) from 2019 to 2049. Simulations are grouped into two numerical analyses. For the first analysis, the rainfall rate decreases by 37.4% (RCP2.6, RCP4.5) together with a sea-level increment of 0.36 m (RCP 4.5); for the second analysis rainfall increases by 11.82% (RCP 6.0, RCP 8.5) and a sea-level increment of 0.5 m (RCP 8.5).In the first analysis (RCP 2.6, RCP 4.5) the groundwater budget decreases by approximately 26% within the study domain, and the water table declines from 1 to 26 m. The second analysis shows a 15.48% increase in the groundwater budget, as the water level rises on average from 0.5 to 8 m. Given the sensitivity of the model results to the choice of future climate scenario, this study indicates the importance of accurate climate change predictions to help local authorities better manage water resources in tropical urban aquifers.

Study area Venafro Mts., southern-central Italy, Mediterranean basin. Study focus Via a collection of geological and hydrogeological data, a flow conceptual model of a carbonate aquifer has been coupled with a numerical model via MODFLOW code and Unsaturated Zone Flow (UZF) package in steady state and transient conditions. Simulation is further implemented with different management scenarios, for facing possible emergencies due to recharge decrease, also simulating a drastic water abstraction cut-off. New hydrological insights for the region Carbonate fractured aquifers are a strategic water resource in the whole Mediterranean area, supplying major metropolitan areas. Despite these huge extensions, such groundwater systems are threatened by increasing drought occurrence and significant human water abstraction. A characterization of a carbonate fractured aquifer (370 km2) located in central-southern Italy has been performed. Venafro Mts. Aquifer (VMA) hosts a strategic resource for the Western Campania Waterworks (WCW) that supplies the populous metropolitan area of Naples, with 3.8 million inhabitants. VMA shows a slow response, with recovery time estimated at the decennial scale, testifying its limited resilience to natural and human pressures. A shift is proposed from passive management to a more comprehensive concept of smart-water monitoring, applied not only to waterworks and pipelines, but also to groundwater resources in the environment.

Shenzhen is the major financial and high-tech center in southern China. The megacity has grown rapidly in the last 40 years with the population increasing from about 30,000 in 1979 to 20 million in 2016. The study area (2,015 km2) is about 42% urban and 58% undeveloped land. The rapid development of the megacity has resulted in severe degradation of the groundwater and surface-water resources and has created a nearly insatiable demand for water, with an average consumption of 2000 × 106 m3/year. Groundwater is an important component of the baseflow of the many streams in the area and is used for potable water supply and irrigation in some of the rural parts of the municipality. This study develops a conceptual model and quantitative framework for assessing the groundwater resources of Shenzhen. The groundwater system consists of shallow aquifers of alluvium and weathered bedrock overlying low permeability igneous and sedimentary rocks. The complex geologic setting was conceptualized as a block structure with blocks bounded by high-angle faults. The water budget in Shenzhen was quantified. The estimated average groundwater discharge is about 12% of annual precipitation. The study provides a starting point to investigate how a megacity such as Shenzhen should manage and protect its groundwater as a strategic resource and environmental asset. It is also a basic management tool for analyzing and contributing to urban drainage concepts such as the “sponge city”.

A hydrogeological conceptual model has been developed that describes the hydrothermal system of Suio Terme (central Italy). The studied area is located along the peri-Tyrrhenian zone of the central Apennines, between the Mesozoic and Cenozoic carbonate platform sequences of the Aurunci Mountains and the volcanic sequences of the Roccamonfina. A multi-disciplinary approach was followed, using new hydrogeological surveys, the interpretation of stratigraphic logs of boreholes and water wells, and geophysical data—seismic sections, shear-wave velocity (Vs) crustal model and gravimetric model. The collected information allowed for construction of a conceptual hydrogeological model and characterization of the hydrothermal system. The Suio hydrothermal system is strongly influenced by the Eastern Aurunci hydrostructure. Along the southeastern side, the top of the hydrostructure sinks to −1,000 m relative to sea level via a series of normal faults which give origin to the Garigliano graben. Geological and hydrogeological data strongly suggest the propagation and mixing of hot fluids, with cold waters coming from the shallow karst circuit. The aquitard distribution, the normal tectonic displacements and the fracturing of the karst hydrostructure strongly influence the hydrothermal basin. Carbon dioxide and other gasses play a key role in the whole circuit, facilitating the development of the hydrothermal system. The current level of knowledge suggests that the origin of the Suio hydrothermalism is the result of interaction between the carbonate reservoir of the Eastern Aurunci Mountains and the hot and deep crust of this peri-Tyrrhenian sector, where the Roccamonfina volcano represents the shallowest expression.

A methodology to evaluate the hydraulic conductivity of the karst media at a regional scale has been proposed, combining pumping tests and the hydrostructural approach, evaluating the hydraulic conductivity of fractured rocks at the block scale. Obtaining hydraulic conductivity values, calibrated at a regional scale, a numerical flow model of the Cassino area has been developed, to validate the methodology and investigate the ambiguity, related to a nonunique hydrogeological conceptual model. The Cassino plain is an intermontane basin with outstanding groundwater resources. The plain is surrounded by karst hydrostructures that feed the Gari Springs and Peccia Springs. Since the 1970s, the study area was the object of detailed investigations with an exceptional density of water-wells and piezometers, representing one of the most important karst study-sites in central-southern Italy. Application of the proposed methodology investigates the hydraulic conductivity tensor at local and regional scales, reawakening geological and hydrogeological issues of a crucial area and tackling the limits of the continuum modelling in karst media.

This paper presents the outcome of photogeological analysis, field survey as well as borehole correlation, to add new data concerning the intermontane Cassino basin and define facies and thickness of its Quaternary deposits. The investigated area is located in the end sector of the Latina Valley, Southern Lazio and belongs to the Lazio–Abruzzi domain. With a maximum extension of 250 km2 and a NW–SE trend, this paleo-lake was created by lava flows from the Roccamonfina volcano, which barred the Latina Valley. The lacustrine facies were described during the 1960s but available bibliographic data about its spatial distribution and its relationship with the Mesozoic–Cenozoic bedrock are scarce. The thickness of Quaternary deposits has been deeply influenced by inherited paleo-morphologies. Indeed the geological reconstruction of the basin has outlined the presence of an underlying horst and graben structure. This latter obscured the contractional tectonics originated by the orogenetic deformation, even if new structures have been recognized at the foot of Montecassino Hill. We infer that a key role has been performed by the Roveto Valley–Atina–Caserta fault, between Atina and San Pietro Infine.

A numerical simulation has been performed through the natural geothermal system of Suio-Castelforte (LT) in order to investigate the hydothermal area and assess its geothermal potentiality. Starting from geological and hydrogeological data a 2D conceptual model has been built. For numerical purpose, the latter idealizes and simplifies the natural system. The area has been affected by a temperature gradient, from low to medium enthalpy, related to the Quaternary volcanism. By a FEM (Finite Element Model) method, using the COMSOL MULTIPHYSICS® software, a homogeneous and isotrope media have been assumed, simulating the groundwater flow and simultaneous heat transfer. Using the porous media approach, Darcy and heat transfer laws have been applied in steady-state conditions. The results have been compared with the collected data and bibliography. © Società Geologica Italiana, Roma 2016.

The study deals with the morphogenetic meaning of several linear scarps that carved the paleo-landsurface of Valle Daria, an extended geomorphological feature located between Barisciano (AQ) and Prata D'Ansidonia (AQ). These villages are situated in the southern termination of the L'Aquila intermontane basin (one of the largest basin of the central Apennines), nearby the epicentral area of the 6th April 2009 earthquake (Mw 6.1). These scarps, up to 3 meters high and up to 1.5 km long, define narrow/elongated flat-bottom depressions, filled by colluvial deposits. These depressions are carved into fluvial-deltaical conglomerates, dated back to the lower Pleistocene. Even if different authors have interpreted these shapes as a paleodrainage or secondary faults, a morphometrical study of the Valle Daria paleo-landsurface provided several information which cast doubt on these two interpretations. In order to better understand the nature and the state of activity of these lineaments, geological, geomorphological and geophysical surveys were carried out. A paleoseismological trench pointed out two events of deformation. The curvilinear shape of the shear plane seems to be related to a slow deformation, attributable to collapse-phenomena. Three GPR profiles, two ERT profiles and two microgravimetrical profiles seem to corroborate this interpretation. Therefore this study permits to attribute the genesis of these scarps to tectono-karstic phenomena, excluding the presence of an active and capable fault.

A numerical simulation has been performed through the Cassino plain, in order to test the contrasting hydrogeological conceptual-models, available in literature. The studied area shows two huge springs (Gari and Peccia springs) located on the edge of the Cassino plain. For numerical purposes, a 2D hydrogeological section has been built. The analysis followed a FEM (Finite Element Model) method by the software COMSOL®, assuming homogeneous and isotrope media. Using a porous approach, the Darcy law has been applied. The Gari-Peccia communication model has been studied from a numerical point of view, in order to quantify a possible underground flow. Since the model is affected by several approximations, the discharge ratio has been calculated, downstream and upstream Gari springs. The obtained results have been compared with field results from literature.

In the present work, the Differential SAR Interferometry (DInSAR) technique has been applied to study the surface movements affecting the sedimentary basin of Cassino municipality. Two datasets of SAR images, provided by ERS 1-2 and Envisat missions, have been acquired from 1992 to 2010. Such datasets have been processed independently each other and with different techniques nevertheless providing compatible results. DInSAR data show a subsidence rate mostly located in the northeast side of the city, with a subsidence rate decreasing from about 5–6 mm/yr in the period 1992–2000 to about 1–2 mm/yr between 2004 and 2010, highlighting a progressive reduction of the phenomenon. Based on interferometric results and geological/geotechnical observations, the explanation of the detected movements allows to confirm the anthropogenic (surface effect due to building construction) and geological causes (thickness and characteristics of the compressible stratum).

Thanks to its favourable hydrogeological conditions, Cassino is one of the most studied sites of Central Italy. More than two hundred soil borings, some of them reaching depths as high as 100 m, have revealed a subsoil characterized by a calcareous platform and post-orogenetic series forming a tectonic basin filled by lacustrine and volcanic deposits. Together with the already available data, a number of geological, geotechnical and geophysical data have collected to study at a very detailed scale the seismic response of the site. Among them, a series of HVSR (horizontal to vertical spectral ratio) measurements have been performed to estimate the natural frequency of oscillation of the more deformable deposits. The combination of these data with the information given by the deep boreholes, permitted to rebuild the geological complexities of the tectonically driven seismic bedrock, outcropping continuously at east and west of the basin. This study forms the basis for mono, bi and three-dimensional numerical analyses aimed at predicting local amplification effects.

Since the beginning of the ongoing Amatrice seismic sequence on August 24, 2016, initiated by a Mw 6.0 normal faulting earthquake, the EMERGEO Working Group (an INGV team devoted to earthquake aftermath geological survey) set off to investigate any coseismic effects on the natural environment. Up to now, we surveyed about 750 km2 and collected more than 3200 geological observations as differently oriented tectonic fractures together with intermediate- to small- sized landslides, that were mapped in the whole area. The most impressive coseismic evidence was found along the known active Mt. Vettore fault system, where surface ruptures with clear vertical/horizontal offset were observed for more than 5 km, while unclear and discontinuous coseismic features were recorded along the Laga Mts. Fault systems.