Hydrocomplexity, and spatial and time scales as drivers of monitoring and management approaches for a karst coastal aquifer (Salento, southern Italy)

Hydrogeological scenario, Salento aquifer, monitoring wells

Rainwater Harvesting for Agricultural Irrigation: An Analysis of Global Research

Within a context of scarce water resources for agriculture, rainwater harvesting constitutes a promising alternative that has been studied by different disciplines in recent years. This article analyses the dynamics of global research on rainwater harvesting for agricultural irrigation over the last two decades. To do this, qualitative systematic analysis and quantitative bibliometric analysis have been carried out. The results reveal that this line of research is becoming increasingly important within research on irrigation. Environmental sciences and agricultural and biological sciences are the most relevant subject areas. Agricultural Water Management, Physics and Chemistry of the Earth, and Irrigation and Drainage are the journals that have published the most articles on the subject. India, China, the United States (USA), South Africa, and the Netherlands are the countries that lead this line of research. Although significant progress has been made in this subject area, it is necessary to increase the number of studies on the capacity of rainwater harvesting systems to cover irrigation needs in different farming contexts, the factors that determine their adoption by farmers, the economic and financial feasibility of their implementation, and their contribution to mitigating global climate change

Sustainable Irrigation in Agriculture: An Analysis of Global Research

Irrigated agriculture plays a fundamental role as a supplier of food and raw materials. However, it is also the world’s largest water user. In recent years, there has been an increase in the number of studies analyzing agricultural irrigation from the perspective of sustainability with a focus on its environmental, economic, and social impacts. This study seeks to analyze the dynamics of global research in sustainable irrigation in agriculture between 1999 and 2018, including the main agents promoting it and the topics that have received the most attention. To do this, a review and a bibliometric analysis were carried out on a sample of 713 articles. The results show that sustainability is a line of study that is becoming increasingly more prominent within research in irrigation. The study also reveals the existence of substantial differences and preferred topics in the research undertaken by different countries. The priority issues addressed in the research were climatic change, environmental impact, and natural resources conservation; unconventional water resources; irrigation technology and innovation; and water use efficiency. Finally, the findings indicate a series of areas related to sustainable irrigation in agriculture in which research should be promoted

Kinematic patterns of tectonic displacements in the Blue Clay outcrops along the eastern border of the Bradanic Trough (Southern Italy) from {DTM} data processing

The Bradanic Trough (Southern Italy) is the Pliocene-present-day south Apennines foredeep. It is filled by a thick Pliocene to Pleistocene sedimentary succession constituted by hemipelagites (Blue Clay Fm.) in the lower part, and coarse grained deposits (sands and conglomerates) in the upper part, shaped in marine or continental terraced environment. On the eastern border of the Bradanic Trough along the Murgian Plateau (Apulia, Italy) numerous morphological lineaments are associated with sequential lowering and rotation of the surface, aligned with the carbonate substrate dip direction. These morphologies have been interpreted so far as erosion products; their association with medium-deep water circulations and surface phenomena, like mud volcanoes, now allows their interpretation as a lumped mass, detached and tilted along shear surfaces. The surface patterns of such surfaces may be easily detected for the presence, at some distance, of a quite similar twin track, which overlaps with good agreement. The numerical analysis of the tracks extracted from accurate DTMs allows us to reconstruct the kinematic patterns of the tectonic displacement (distance of the detachment; rotation; angle of the shear plane). This type of analysis might reveal very useful in some fields of engineering geology, such as underground works, and for interpreting many hydrogeological phenomena within the study area. Finally, the correct 3D representation of the detached masses helps to identify the true causes of the direct faulting, which is not always linked to the tectonics, not active in the concerned regions

Groundwater Temperature as an Indicator of the Vulnerability of Karst Coastal Aquifers

Coastal karst aquifers show a three-dimensional vulnerability, which consists of the whole of the “intrinsic vulnerability” and the “groundwater vulnerability to seawater intrusion”. The results of a study carried out in the Salento karst coastal aquifer (southern Italy) show that temperature, as well as being a reliable tracer of groundwater flow, is also an effective indicator of vulnerability in anisotropic media. The trend of isotherms related to a cross-section of the aquifer thermal field, combined with geological, geomorphological, and hydrogeological information, allows the role of faults and dolines in the mass transport from ground surface to be inferred. Isotherm trends may also give information on the permeability distribution along faults. A specific temperature value evidence the saltwater top, thus indicating the groundwater vulnerability to salinization

Groundwater Drought Analysis under Data Scarcity: The Case of the Salento Aquifer (Italy)

Salento is a regional coastal karst aquifer located in Southern Italy with a highly complex geological, geomorphological, and hydrogeological structure. High and unruly exploitation of groundwater from licensed and unlicensed wells for irrigation and drinking purposes affects groundwater, with consequent degradation of its qualitative and quantitative status. The increased frequency of meteorological droughts and rising temperatures may only worsen the already compromised situation. The absence of complete and enduring monitoring of groundwater levels prevents the application of some methodologies, which require long time series. The analysis of climate indexes to describe the groundwater level variation is a possible approach under data scarcity. However, this approach may not be obvious for complex aquifers (in terms of scale, intrinsic properties, and boundary conditions) where the response of the groundwater to precipitation is not necessarily linear. Thus, the proposed research deals with the assessment of the response of the Salento aquifer to precipitation variability based on correlations between the Standardized Precipitation Index (SPI) and Standardized Precipitation and Evapotranspiration Index (SPEI) and groundwater levels for nine monitoring wells from July 2007 to December 2011. The study aims at evaluating the ability of the above indicators to explain the behavior of groundwater on complex aquifers. Moreover, it has the general aim to verify their more general reliable application. Results of three different correlation factors outline direct and statistically significant correlations between the time series. They describe the Salento aquifer as a slow filter, with a notable inertial behavior in response to meteorological events. The SPI 18-months demonstrates to be a viable candidate to predict the groundwater response to precipitation variability for the Salento aquifer

Climate change and future groundwater level projections for the Salento Aquifer (Italy)

Groundwater is a vital source of fresh water in many areas of the  Mediterranean Basin and it will become increasingly important due to climate  change and the resulting intensification in water scarcity. The Salento peninsula  (Puglia region) in southern Italy is no exception, where groundwater is the main  source mostly for drinking and irrigation purposes. In fact, the karst nature of the  Salento territory allows the presence of groundwater resources rather than  surface water resources. The recharge conditions of this aquifer are very complex  since its geological and hydrogeological structures are complex. In addition to  this, the scarcity of data prevents to understand all the phenomena as a whole  and to setup integrated surface/groundwater models that could be useful for  investigating the impacts of climate change on the Salento groundwater  resources. However, for the Salento area, a direct correlation between  hydrological variables (precipitation and temperature) and groundwater levels  (GWLs) has been shown. In particular, despite the complexity of the aquifer, it is  possible to define potential linear relationships between observed meteorological indices, such as the Standardized Precipitation Index (SPI) and the Standardized  Precipitation Evapotranspiration Index (SPEI), and GWLs collected in monitoring  wells. In most cases, there are high correlation coefficients between SPI/SPEI and  GWLs for long accumulation periods of the climate variables, in the order of 18  months. This, for the aquifer studied, reflects the attenuated response of  groundwater to precipitation/precipitation-evapotranspiration signals. In this  work, we use future projections of SPIs and SPEIs for the Salento area to estimate  the possible impacts of climate change on the groundwater resource. In  particular, for this study, we computed SPI and SPEI projections, until the end of  this century, from future precipitation and temperature data of an ensemble of  Regional Climate Models (RCMs) of the EURO-CORDEX initiative, under two climate scenarios, namely the RCP4.5 and the RCP8.5. Prior to their use, the raw  RCM data were downscaled/bias corrected to properly represent the observed  climate in the study area. Under the hypothesis that the observed linear  relationships between meteorological indices and GWLs remain valid over time,  we obtained future projections of GWLs from the projections of SPIs/SPEIs. The  analysis of the future GWLs has been conducted at short-, medium- and long term. The use of an ensemble of climate models allows in evaluating the  uncertainty of the results. As long as a high correlation between meteorological  indices and GWLs exists, the approach used in this work can be easily applicable  to other study areas

Hydrogeology of the Nurra Region, Sardinia (Italy): basement-cover influences on groundwater occurrence and hydrogeochemistry

The Nurra district in the Island of Sardinia (Italy) has a Palaeozoic basement and covers, consisting of Mesozoic carbonates, Cenozoic pyroclastic rocks and Quaternary, mainly clastic, sediments. The faulting and folding affecting the covers predominantly control the geomorphology. The morphology of the southern part is controlled by the Tertiary volcanic activity that generated a stack of pyroclastic flows. Geological structures and lithology exert the main control on recharge and groundwater circulation, as well as its availability and quality. The watershed divides do not fit the groundwater divide; the latter is conditioned by open folds and by faults. The Mesozoic folded carbonate sequences contain appreciable amounts of groundwater, particularly where structural lows are generated by synclines and normal faults. The regional groundwater flow has been defined. The investigated groundwater shows relatively high TDS and chloride concentrations which, along with other hydrogeochemical evidence, rules out sea-water intrusion as the cause of high salinity. The high chloride and sulphate concentrations can be related to deep hydrothermal circuits and to Triassic evaporites, respectively. The source water chemistry has been modified by various geochemical processes due to the groundwater–rock interaction, including ion exchange with hydrothermal minerals and clays, incongruent solution of dolomite, and sulphate reduction

Rainwater Harvesting for Agricultural Irrigation: An Analysis of Global Research

Within a context of scarce water resources for agriculture, rainwater harvesting constitutes a promising alternative that has been studied by different disciplines in recent years. This article analyses the dynamics of global research on rainwater harvesting for agricultural irrigation over the last two decades. To do this, qualitative systematic analysis and quantitative bibliometric analysis have been carried out. The results reveal that this line of research is becoming increasingly important within research on irrigation. Environmental sciences and agricultural and biological sciences are the most relevant subject areas. Agricultural Water Management, Physics and Chemistry of the Earth, and Irrigation and Drainage are the journals that have published the most articles on the subject. India, China, the United States (USA), South Africa, and the Netherlands are the countries that lead this line of research. Although significant progress has been made in this subject area, it is necessary to increase the number of studies on the capacity of rainwater harvesting systems to cover irrigation needs in different farming contexts, the factors that determine their adoption by farmers, the economic and financial feasibility of their implementation, and their contribution to mitigating global climate change

Sustainable Irrigation in Agriculture: An Analysis of Global Research

Irrigated agriculture plays a fundamental role as a supplier of food and raw materials. However, it is also the world’s largest water user. In recent years, there has been an increase in the number of studies analyzing agricultural irrigation from the perspective of sustainability with a focus on its environmental, economic, and social impacts. This study seeks to analyze the dynamics of global research in sustainable irrigation in agriculture between 1999 and 2018, including the main agents promoting it and the topics that have received the most attention. To do this, a review and a bibliometric analysis were carried out on a sample of 713 articles. The results show that sustainability is a line of study that is becoming increasingly more prominent within research in irrigation. The study also reveals the existence of substantial differences and preferred topics in the research undertaken by different countries. The priority issues addressed in the research were climatic change, environmental impact, and natural resources conservation; unconventional water resources; irrigation technology and innovation; and water use efficiency. Finally, the findings indicate a series of areas related to sustainable irrigation in agriculture in which research should be promoted