The 6th National Meeting on Hydrogeology Flowpath 2023

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The evolution of water culture in Malta : an analysis of the changing perceptions towards water throughout the ages

Since time immemorial, the provision of water in sufficient quantities has been one of the most pressing national problems. This paper will try to analyze the changing public perceptions towards water and its use throughout the last two millennia, through the development of a correlation between the prevalent social and economic changes experienced.To this end, the background social and environmental conditions characterizing four distinct periods in Maltese history will be analyzed, in order to determine their effects on the popular perception to water.peer-reviewe

A hydrogeological study to support the optimized management of the main sea level aquifer of the island of Malta

Management groundwater resources, coastal aquifer, seawater intrusion, safe-yield, Malta

A risk assessment methodology to evaluate the risk failure of managed aquifer recharge in the Mediterranean Basin

Managed aquifer recharge (MAR) can be affected by many risks. Those risks are related to different technical and non-technical aspects of recharge, like water availability, water quality, legislation, social issues, etc. Many other works have acknowledged risks of this nature theoretically; however, their quantification and definition has not been developed. In this study, the risk definition and quantification has been performed by means of "fault trees" and probabilistic risk assessment (PRA). We defined a fault tree with 65 basic events applicable to the operation phase. After that, we have applied this methodology to six different managed aquifer recharge sites located in the Mediterranean Basin (Portugal, Spain, Italy, Malta, and Israel). The probabilities of the basic events were defined by expert criteria, based on the knowledge of the different managers of the facilities. From that, we conclude that in all sites, the perception of the expert criteria of the non-technical aspects were as much or even more important than the technical aspects. Regarding the risk results, we observe that the total risk in three of the six sites was equal to or above 0.90. That would mean that the MAR facilities have a risk of failure equal to or higher than 90¿% in the period of 2–6 years. The other three sites presented lower risks (75, 29, and 18¿% for Malta, Menashe, and Serchio, respectively). Managed aquifer recharge (MAR) can be affected by many risks. Those risks are related to different technical and non-technical aspects of recharge, like water availability, water quality, legislation, social issues, etc. Many other works have acknowledged risks of this nature theoretically; however, their quantification and definition has not been developed. In this study, the risk definition and quantification has been performed by means of "fault trees" and probabilistic risk assessment (PRA). We defined a fault tree with 65 basic events applicable to the operation phase. After that, we have applied this methodology to six different managed aquifer recharge sites located in the Mediterranean Basin (Portugal, Spain, Italy, Malta, and Israel). The probabilities of the basic events were defined by expert criteria, based on the knowledge of the different managers of the facilities. From that, we conclude that in all sites, the perception of the expert criteria of the non-technical aspects were as much or even more important than the technical aspects. Regarding the risk results, we observe that the total risk in three of the six sites was equal to or above 0.90. That would mean that the MAR facilities have a risk of failure equal to or higher than 90 % in the period of 2–6 years. The other three sites presented lower risks (75, 29, and 18 % for Malta, Menashe, and Serchio, respectively)

Spatial Data Management and Numerical Modelling: Demonstrating the Application of the QGIS-Integrated FREEWAT Platform at 13 Case Studies for Tackling Groundwater Resource Management

Because of the spatial nature of groundwater-related data and their time component, effective groundwater management requires the application of methods pertaining to the Information and Communication Technologies sector, such as spatial data management and distributed numerical modelling. The objective of this paper is to demonstrate the effectiveness of the QGIS-integrated FREEWAT platform and an approach combining spatial data management and numerical models to target groundwater management issues. FREEWAT is a free and open source platform integrated in a Geographic Information System environment and embedding tools for pre- and post-processing of spatial data and integrating numerical codes for the simulation of the hydrological cycle, with a main focus on groundwater. To this aim, this paper briefly presents the FREEWAT platform, introduces the FREEWAT approach, and showcases 13 case studies in European and non-European countries where the FREEWAT platform was applied. Application of the FREEWAT platform to real-world case studies is presented for targeting management of coastal aquifers, ground- and surface-water interaction, climate change impacts, management of transboundary aquifers, rural water management and protection of groundwater-dependent ecosystems. In this sense, compared to other existing software suites, FREEWAT allows data analysis and visualization to accomplish each step of the modelling workflow, i.e., from data analytics, to conceptual model definition, to numerical modelling and reporting of results. The presented experiences demonstrate that improved access to data and the portability of models and models’ results can help to promote water sustainability from the local- to the basin-scale. Furthermore, FREEWAT may represent a valuable tool to target the objective of increasing the capabilities of public authorities and private companies to manage groundwater resources by means of up-to-date, robust, well-documented and reliable software, without entailing the need of costly licensing, nowadays seldom affordable by public water authorities. Based on the strengths highlighted, the FREEWAT platform is a powerful tool for groundwater resources management, and for data collection, sharing, implementation and comparison of scenarios, for supporting planning and decision-making

The seventh national communication of Malta under the United Nations framework convention on climate change

This is the fourth time that Malta is submitting a National Communication under the United Nations Framework Convention on Climate Change (UNFCCC), following the submission of a First National Communication in 2004 and a Second National Communication in 2010. This is also the second time that Malta is submitting such a Communication since its accession to Annex I status under the Convention, the first two submissions having been made as a non-Annex I Party. Emission reduction or limitation commitments applicable to Malta Malta’s status under the Convention up to the time it applied for accession to Annex I, and with that accession being conditional to not taking on quantified emission limitation or reduction targets for the first commitment period of the Kyoto Protocol, meant that until 2012 Malta was not subject to an economy-wide greenhouse gas related obligation under the Protocol. This however did not mean that Malta had no obligations to limit or reduce emissions from anthropogenic activities taking place in the country. In line with, Malta will be contributing its fair share of the EU’s unconditional commitment under the Convention to reduce emissions by 20% below 1990 levels by 2020. This is in line with the target inscribed in the amendments to the Kyoto Protocol (the Doha Amendments), that will be jointly fulfilling the second commitment period with the other Union member states; therefore, emissions from the aforementioned power plants remain subject to compliance with EU Emissions Trading Scheme provisions, while the Effort-Sharing Decision target is the principal emissions mitigation obligation that the country has until 2020, for all other greenhouse gas emissions. The major point sources of greenhouse gas emissions in Malta, namely the electricity generation plants have been, since of 2005, subject to the EU Emissions Trading Scheme, whereby they are required to surrender allowances in respect of emissions of carbon dioxide. Emissions of greenhouse gases not covered by the EU Emissions Trading Scheme, are subject to an overall limit under the so-called Effort-Sharing Decision. Under this decision, Malta must limit such greenhouse gases to not more than 5% over emission levels in 2005, by 2020. The EU is already looking towards the longer-term future, with the 2030 climate and energy framework providing for a 40% domestic reduction target for 2030. Legislative implementation of this goal is currently under discussion at EU level.peer-reviewe

Groundwater residence time in Malta

The Maltese Islands are composed of Oligocene and Miocene coralline limestones which contain two aquifers, separated by the more poorly-permeable Globigerina Limestone. The lower ‘sea level’ aquifer exhibits a classic Ghyben-Herzberg lens which has been modified by heavy groundwater abstraction from sea-level pumping station galleries. Malta is dependent on groundwater for both public supply and irrigation as there is limited surface water. Water levels and spring flows in the upper ‘perched’ aquifer and in some areas of the lower aquifer respond quickly to rainfall and together with some visible karstic features has lead to the assumption that this is a predominantly rapid-flow system. However, tritium studies reported in 2003 by Bakalovich and Mangion and our recent residence time studies show that the bulk of water in the saturated zone moves slowly with a travel time of decades. This is in agreement with the estimated water balance which indicates that annual replenishment is low compared to the estimated storage. Microbiological work suggests that there are limited rapid pathways through the unsaturated zone and water movement must be primarily through the matrix. Where the unsaturated zone is thick the travel time may also be decades. This new model has profound implications for aquifer management, particularly with respect to the obligations of the Water Framework Directive

Report on Improving Water Quality at Active MAR Sites in Spain

Managed Aquifer Recharge (MAR) is a promising technique for water management. It comprises a group of technologies that enhance the infiltration of various water sources into aquifers. The water stored underground can serve different uses, such as irrigation, industrial and drinking water supply, and the recovery or preservation of environmental assets. Globally, water resources are increasingly under pressure. MAR offers the potential to buffer water resource availability and meet demands in periods of water scarcity. Consequently, the uptake of this technique will likely soar in the next decades due to current pressure on water resources and the consequences of climate change, requiring highly trained practitioners that can provide the knowledge and know-how on MAR implementation. The present report is part of the Managed Aquifer Recharge Solution Training Network (MARSoluT ITN, 2019-2023), which aimed to train experts in MAR. The report deals with the objectives of work package four (WP4) of the MARSoluT project and aims at helping to improve water quality by optimising MAR design at active MAR sites in Spain. The report tackles four knowledge gaps on MAR in relation to water quality: (i) the need for a review of current regulations on MAR and how they use Maximum Allowable Concentrations (MACs) to prevent water pollution during MAR; (ii) a discussion on the current challenges for MAR water quality; (iii) the lack of a conceptual model that can help in the creation of regulation, rules, and guidelines on MAR; and (iv) the need for testing the efficacy of MACs at the national level with a focus on Spain. Although this report focuses on Spain, it does not restrict its development to this country and has a relatively broad scope, providing solutions for MAR worldwide. The methodologies in the current report are mostly based on literature review of scientific, technical and regulatory documents and the exploitation of published and unpublished water quality analyses and water quality standards involving MAR. For the first knowledge gap, a comprehensive review of existing regulations and guidelines for MAR was conducted, and an analysis of MACs in water quality standards from diverse sources globally was completed. To respond to the second knowledge gap, a discussion on modern water quality challenges for MAR is provided, including the context, history, future and the need for a risk-based approach. The Monitored and Intentional Recharge (MIR) conceptual model is a response to knowledge gap three, comprising a set of nine blocks that elaborates on the most critical aspects that must be considered to draft MAR regulations and guidelines. This section also entails a series of recommendations directed to future regulations on MAR, including developing a common terminology with legal implications, considering a permitting process, new legal development, the inclusion of budgetary aspects, regard to the technical background for authorisation, and the fact that water standards for MAR must be designed at the aquifer level. The fourth knowledge gap was addressed through an analysis of source water quality in MAR sites in Spain and a comparison between them and three European MAC-based standards (Italy, Spain, and the Netherlands) to evaluate the efficacy of MAC in dealing with water pollution at MAR sites. This section showed the high variability in terms of water quality at 11 MAR sites and the inadequacy of MAC-based standards to control pollution while allowing for MAR implementation at the national or European levels. This sort of standard could be useful aquifer-wide. This analysis also concluded that focus on quality should be given to the final quality of the water after MAR rather than the original water quality, and that the attenuation processes in the saturated and unsaturated zones should be regarded. Finally, biochar, a promising low-cost material to remove multiple pollutants during MAR, has been thoroughly studied. This report also emphasises that, nowadays, MAR is an option, but in the future will likely become a necessity, and that there is a need to continue investing in (1) applied research to improve insights into the development of freshwater cones in saline environments, (2) define measures to increase the efficiency of MAR systems and social acceptance, and (3), consider the beneficial impact of the unsaturated and saturated zones

Determining Aquifer Hydrogeological Parameters in Coastal Aquifers from Tidal Attenuation Analysis, Case Study: The Malta Mean Sea Level Aquifer System

The coastal and carbonate Mean Sea Level Aquifer (MSLA) of Malta is characterised by high anisotropy and heterogeneity, which together make evaluating the aquifer system parameters a challenging task. In this paper, we present an approach for the determination of the hydrogeological parameters of this coastal aquifer based on tidal-induced groundwater fluctuations that can be applied in other similar contexts. This work presents an analysis of data undertaken on monitoring boreholes located in the Malta MSLA exhibiting tidal-induced groundwater fluctuations. This allowed us to determine the values of three main hydrogeological parameters: hydraulic diffusivity, transmissivity and hydraulic conductivity. These will subsequently be used as an input for groundwater flow and reactive transport modelling purposes. In this study, a methodology based on the fast Fourier transform (FFT) is proposed to improve the applicability of the Jacob–Ferris method to the observed groundwater level and sea level fluctuations. The FFT reproduced signals allowed us to isolate the component induced by sea tides, thus eliminating short- and long-term variations of the water table induced by other disruptive factors. Results showed high variability of hydrogeological parameters within a short distance, reflecting the high anisotropy and heterogeneity of the aquifer system. The transmissivity values derived from the Jacob–Ferris method are complemented with results derived from the pumping tests with the aim of estimating the spatial distribution of the aquifer transmissivity for the study area. The spatial variability of transmissivity values is analysed by means of geostatistics tools for estimating uncertainty, correlation and variation in space through the use of semi-variograms

Report on the performance of optimal MAR designs

Managed Aquifer Recharge (MAR) is a promising technique for water management. It comprises a group of technologies that enhance the infiltration of various water sources into aquifers. The water stored underground can serve different uses, such as irrigation, industrial and drinking water supply, and the recovery or preservation of environmental assets. The uptake of MAR is rapidly increasing worldwide under the threat of multiple pressures, including climate change, the decline in aquifer storage and environmental degradation. The present report is part of the Horizon 2020 MSCA "Managed Aquifer Recharge Solutions Training Network" (MARSoluT ITN, 2019-2023), which aimed at training experts in MAR (https://www.marsolut-itn.eu/). Report D4.4 deals with the objectives of work package 4 (WP4) and seeks to evaluate the performance of MAR sites across the Mediterranean using monitoring data. D4.4 continues a line of research started in the FP7 project "Demonstrating Managed Aquifer Recharge as a Solution to Water Scarcity and Drought" (MARSOL, 2013-2016) through MARSOL work package 13 (WP13) and its Deliverables D13.1 and D13.3, which provided technical solutions for MAR. The performance of six MAR sites across the Mediterranean was evaluated, namely, The Algarve, Portugal (UAlg); The Los Arenales MAR sites, Spain (TRAGSA); the Suvereto MAR site, Italy (SSSA); the Pwales MAR site, Malta, (EWA); the Argolis Field, Greece (NTUA); and the Menashe streams MAR site, Israel (ARO). The performance was evaluated in terms of seven categories: yearly recharge volumes, impacts on groundwater levels, impacts on water quality, infiltration rates and clogging, site upgrade, financial aspects, and other aspects. The site performance evaluation involved research conducted primarily within the framework of the MARSoluT project. In general, the sites show satisfactory performance after several years of operations. In the Algarve, MAR could help to palliate some of the current issues, but other measures are also required. In addition, a calculation for the unintentional recharge of groundwater caused by transversal structures (dykes and dams) has been conducted as a starting point for a future more accurate estimation. The volume infiltrated from the about 27,600 in-river structures ranges between 800 and 1,200 Mm3/year for the Spanish territory, representing a starting point for this new line of action about (un)managed aquifer recharge at a large scale. The obtained figures will be fine-tuned in the future of this initial figure. The site performance evaluation research involves multiple tools and diverse approaches, including numerical groundwater modelling, analytical hydrochemical characterisation, field and laboratory experiments, and geospatial analysis. A total of 20 technical solutions were added to the list that started in MARSOL with Deliverable D13.1. These technological solutions are related to multiple aspects of MAR, such as operation, planning, maintenance, and site upgrade. The advances in MAR sciences and engineering reflected in this report showcase successful MAR experiences and provide technical solutions that can support the market penetration of MAR in the Mediterranean region and beyond