Accounting for Climate Change and Drought in Implementing Sustainable Groundwater Management

Numerical models are capable of simulating various groundwater scenarios and relate it towards groundwater management. This paper focuses on numerical modeling and water balance approaches in the search for a sustainable management plan in Manukan Island. The impacts of pumping and recharge rates represented by groundwater scenarios were investigated by means of hydraulic heads, chloride concentrations and water balance components. Overpumping and inconsistency in recharge rate are the stresses shown in Scenario A. Scenario B involved with reduction pumping rate by 25% has shown an increase in groundwater levels, chloride concentration and groundwater storage. Scenario C showed the most promising finding compared with Scenarios A and B. Highest hydraulic heads, lowest chloride concentration (1,552.2 mg/L) and positive groundwater storage (254.3 m3/day) were obtained in Scenario C. Chloride concentration in pumping wells still exceeds World Health Organization International Standard limit in Scenario C which illustrates an additional water treatment is needed. Nevertheless, in view of a compromise groundwater management plan in study area, Scenario C is the best plan so far to protect the groundwater resources in the study area. More understanding of the artificial recharge method (percolation tank) and study site by means of modeling studies is needed. Additionally, further progress is needed in obtaining the water usage data from each part to determine the best pumping rate. A sustainable groundwater management plan is crucial to maintain the natural resources and social benefits as well as to protect the ecological balance of Manukan Island.

Water is fundamental to life and a vital element for sustainable development. In Germany, groundwater systems are increasingly facing challenges due to climate change and competing demands from various sectors, including drinking water supply, agriculture, forestry, industry, and energy. For the past twenty years, many areas have experienced a noticeable drop in groundwater levels. This situation highlights the urgent need for meticulous management of this essential resource. The complexity of Germany’s groundwater systems further complicates this task. In response to these issues, Germany’s Federal Ministry of Education and Research (BMBF) has launched the "Sustainable Groundwater Management" (LURCH) funding measure. It is designed to promote sustainable groundwater management across the country and ensure its protection as a crucial drinking water source and ecological resource. The LURCH research projects address both quantitative and qualitative challenges in groundwater management, focusing on sustainable resource protection and climate adaptation. They aim to develop an integrated understanding of aquifer systems, considering natural interfaces such as surface waters, groundwater recharge, and saline water interactions, alongside various water uses in drinking water supply, agriculture, forestry, and industry. Groundwater’s role as a thermal reservoir and its ecological functions are also explored. The research tackles pollution risks from nitrate, trace substances, and pathogens while advancing analytical methods and technological innovations, including in-situ treatment and monitoring. Additionally, sustainable management strategies consider economic feasibility, investment, and operating costs, supported by digital tools for improved decision-making. With a strong emphasis on practical implementation, the projects develop solutions to help stakeholders in water supply, agriculture, and industry adapt to climate change and ensure the long-term resilience of groundwater resources. This paper aims to summarize the background and the objectives of the BMBF LURCH funding measure and will introduce the 10 joint projects in a nutshell. It is an introduction to the new ESEU series on Groundwater, which provides an overview of the planned activities within LURCH and highlights the developed solutions. Beyond introducing several joint projects funded by the LURCH funding measure, this collection of papers will publish original research papers, reviews, opinion papers and policy briefs developed based on LURCH projects. By bringing together diverse perspectives, we aim to address the challenges and opportunities associated with protecting this vital resource.

Integrated Water Resources Management in Practice: Better Water Management for Development , R. Lenton and M. Muller ( Editors ). Earthscan , 22883 Quicksilver Dr., Sterling, Virginia 20166-2012 . 2009 . 228 pages. $78 . ISBN 978-1-84407-650-5 . This book is a welcome addition to the literature promoting integrated water resources management (IWRM). Robert Lenton and Mike Muller make a strong case for better management of water resources using the IWRM approach, widely recognized as the most appropriate way to address a wide range of water-related development and environmental issues confronting mankind today. The presentation of recent achievements and future possibilities in equitably and sustainably managing water resources toward meeting economic and social goals and insure environmental integrity in different parts of the world may be considered a benchmark that bodes well for further progress. The book begins with an introduction to the principles and practices of IWRM, which remain poorly understood, even in the water sector and development arena. This chapter also outlines the conceptual framework used in this book, which sets it apart from other publications. This includes a focus not only on processes in IWRM (e.g., changes in policy, laws, and organizational structures) but also the ultimate outcome and impact of using this approach, rendering the book as a much needed practical guide for planners and practitioners. The four spatially structured parts of the book take the reader from the local to the basin, national, and transnational levels. Twelve of the 14 chapters present case studies in East and Southeast Asia (five chapters), Africa and Latin America (two chapters each), and in Europe, North America, and Australia (one chapter each). The case studies document how better water management guided by the IWRM approach significantly contributed to achieve a large number of development goals in different communities and countries with different socioeconomic and environmental conditions and scales. While the editors duly acknowledge the challenge of deriving overall conclusions about what works and what does not work in different settings, they are able to succinctly and convincingly distill the various strands running through the book in the Conclusion. By considering the major objectives, processes, and outcomes of good water management, the management of water at different scales, and the nature of the IWRM approach itself in the context of the various chapter studies, they conclude that in all of the cases described the basic approach that was applied recognized the following elements: (1) the unitary nature of the water resource that recognizes the interconnectedness of surface, ground, and evaporated water, (2) the physical interventions that could be adopted to manage it, (3) the limits to those physical interventions, and (4) the need for an institutional framework that brought stakeholders together in an equitable manner and gave voice to both the weak and powerful, sought to achieve a balance of interests among them, identified the environmental dimension of water management and developed organizations able to promote the overall approach. The editors further note that these elements utilized in nearly all cases presented in the book were not considered to be explicit applications of the IWRM approach but rather began before the concept was formalized (as in India, Chile, Japan, Mexico, and China) or were incidental (in South Africa and Australia). These facts help to dispel the notion that IWRM is an unrealistic, overly ambitious approach and a fixed prescription that requires the employment of all available tools in its arsenal or a magic bullet. Similarly, the focus on individual tools has tended to hamper water management and the establishment of river basin organizations as a routine first step has played only a secondary role in improving water management in many cases (in South Africa and Chile, for example) and no role in others (Japan and Denmark). These findings strengthen the editors’ argument that IWRM offers a flexible and adaptable framework within which a wide range of water and development problems in different communities and countries can be addressed. Also highlighted in the Conclusion are remaining challenges in applying IWRM in practice. They include overcoming implementation difficulties at the macro-level; finding the proper mix of formal and informal mechanisms in operations; the need for more flexible as well as community-specific and system-wide planning and management rather than blueprint packages in many developing countries; and challenges for integration arising at the interface between water, sectoral, territorial, and organizational systems, particularly governance and participation issues at the international transboundary level. The writing style is lucid and captivating and the focus on real world examples rather than theoretical constructs captivate the inquisitive mind, making it difficult to put the book down. The few typographical errors do not detract from the quality of the presentation. Three relatively minor technical problems – the use of the same gray tones for different categories of water stress indicators in Figure 1.1 instead of using a color scheme, the poor print quality of this world map (all other figures in the book are excellent), and the weak binding I noticed on my paperback copy – should not detract from the intrinsic value of this well conceived and meticulously researched book. As a geographer interested in Third World water resources management and water-related health problems I enjoyed reading the broadly based case studies presented in this much needed book. Planners, water managers, researchers, and students will want to have a copy on their shelves for reference, guidance, and inspiration. Helmut Kloos Department of Epidemiology and Biostatistics University of California San Francisco, California 94134-0560 E-mail: helmutk@comcast.net The Sustainable Management of Groundwater in Canada , The Expert Panel on Groundwater . Council of Canadian Academies , 180 Elgin St., Ste. 1401, Ottawa, Ontario, Canada K2P 2K3 . 2009 . 253 pages . ISBN 978-1-926558-09-7 . I enthusiastically agreed to review this book, The Sustainable Management of Groundwater in Canada (Groundwater) penned by the Expert Panel on Groundwater (Panel) not only because I have a great interest in sustainability issues but also because I had heard much in the popular press about the Athabasca Oil Sands project and I hoped the Panel would discuss energy production and sustainable use of water – I was not disappointed on either count. I do not want to mislead the reader though –Groundwater covers a wide range of topics from governance to flow modeling to markets and case studies. Although Groundwater was written explicitly for or from a Canadian perspective, many if not all of the topics are applicable to work in other countries. Many of the authors that served on the Panel are instantly recognizable names with groundwater and hydrology experience garnered from across the globe (interestingly, but not surprisingly, many of these world renowned authors work in Canada); this breadth and depth of expertise helps to make Groundwater a relatively easy to read book especially given the complex nature of groundwater and sustainability. There are too many topics to discuss in detail in this review. Still, to give the reader a sense of this book, some of the salient topics are reviewed here. The Panel identified five sustainability goals to include protection of groundwater from depletion and contamination, protection of ecosystem viability, achievement of economic and social well being and application of good governance; these individual sustainability goals are envisioned as equal members in the schematic put forth by the Panel. This reader agrees that this pentad of sustainability goals should be implemented in future projects although if history teaches us anything, in practice, these goals might not enjoy equal strength or standing; the Panel offers case studies that illustrate the importance of the implementation of (or, sadly, as the case may be, lack of) sustainability goals. Part of the appeal of Groundwater is the ability of the Panel to explain abstruse concepts by the judicious use of footnotes and many well written topic-boxes. One such footnote on page 17 helps exemplify the pedagogical tenor of Groundwater and (a portion of this particular footnote) is well worth repeating here: “The precautionary principle seeks to encourage those undertaking projects to consider and address harm to the public or the environment even if the scientific consensus that harm will occur is unclear.” Unfortunately, it seems from some of the case studies discussed here, all too often, the precautionary principle has not been applied in many cases. An example of topic-box discussions is given on page 113, where the Panel expands on topics such as the Tragedy of the Commons and water. I cannot help but wonder if present day appropriation schemata, such as the doctrine of prior appropriation, riparian rights, correlative rights, rule of capture, etc., have helped to perpetuate the tragedy. Hopefully, some day soon, the Tragedy of the Commons will be relegated to a footnote in history. The Panel discusses many case studies to help illustrate the effects of climate change (Prairie Groundwater), population growth (Denver Basin), and energy production (Athabasca Oil Sands) on sustainable use of water. Groundwater incites some mental rumination (and this is why I am excited by this type of book) – each of these case studies could also be seen to show how climate change, population growth, and energy production also affect another timely topic – food production and economic security. It should be noted that the Panel briefly discusses bio-fuel production generally – presumably because this topic and technology is in an almost mercurial state of flux. However, probably one of the most important topics discussed in Groundwater concerns the use of “... economic instruments such as water prices, abstraction fees, and tradable permits...” to help manage water. This of course could be seen to be a point of contention in places where present day appropriation rules govern water allocations. Given the stressors that affect water such as climate change, population growth, and food and energy security, economic instruments might offer an attractive means to equitably manage water resources (to be fair the significance of these stressors might not have been recognized in earlier times when various appropriation rules were enacted). The Panel notes numerical modeling simulation studies that “...show a significant improvement in the efficiency of water allocation (relative to current allocations) as a result of water trades.” In the face of these changes in climate and population, it may be time to heed these tocsins presented in the various case studies and perhaps consider a retooling of management and regulations schema. In sum, The Sustainable Management of Groundwater in Canada, is an easy to read book written by an expert panel of world renowned water experts. The topics are fresh and timely and applicable both in Canada as well as other parts of the world. I am glad that I read the book and would suggest that it be included on a must-read list to colleagues. Kevin Jeffrey Spelts Twin Platte Natural Resources District, 302 S. Oak St., North Platte, Nebraska 69101 Fluvial Hydraulics , L. Dingman . Oxford University Press , 198 Madison Ave., New York, New York 10016 . 2009 . 559 pages . ISBN 978-0-19-517286-7 . I became familiar with Professor Dingman’s work when I used his Fluvial Hydrology (Dingman, 1984, now out of print) for my graduate work in channel morphology and sediment transport. Fluvial Hydraulics builds upon the geomorphology and fluvial hydraulics presented in Fluvial Hydrology, but Dingman’s new book includes more information on basic-fluid mechanics and a more extensive discussion of the characteristics of natural rivers. Dingman’s preface to Fluvial Hydraulics states that “The overall goal of this book is to develop a sound qualitative and quantitative understanding of the physics of natural river flows for practitioners and students.” That goal is most certainly met. Fluvial-hydraulics concepts, from basic hydraulic relationships to complex phenomena such as turbulence and hydraulic jumps, are clearly presented. The equation derivations are logical and fairly easy to understand. The figures and photographs are clear and complement understanding of the text. Examples and additional derivations are presented in boxes for the reader who is interested in a deeper understanding of the material. Dingman begins with an Introduction that describes volumes of water in the components of the hydrologic cycle and in the world’s largest rivers. The Introduction also includes a fascinating history of fluvial hydraulics and personalities that advanced the science. Chapters 2, 3, and 4 provide a foundation for the study of open-channel flow. In Chapter 2, Dingman discusses the morphologic and hydrologic characteristics of natural streams; in Chapter 3, he describes water’s atomic and molecular structure and other properties. Then, in Chapter 4, Dingman introduces the basic equations for fluid properties and hydraulic variables, including relationships based on the conservation of mass, momentum, and energy, and equations based on diffusion and force/balance relationships. Equations based on dimensional analysis and empirical and heuristic relations also are described. Chapters 5, 6, and 7 present relationships between velocity and flow resistance, the Prandtl-von Karman vertical-velocity profile, the Chezy, Darcy-Weisbach, and Manning’s equations, and magnitudes of driving and resisting forces in natural streams. The next two chapters discuss momentum and energy principles, equations for gradually-varied flow, and methods for calculating water-surface profiles. In Chapter 10, Dingman describes steady, rapidly-varied flow, including analysis of hydraulics at abrupt transitions and structures for discharge measurement. In Chapter 11, he discusses unsteady flow, including an excellent description of waves and prediction of wave depths and speed of travel. In Chapter 12, he discusses sediment entrainment and transport, including sediment-transport measurement, factors that dictate the shape of alluvial channel cross sections, and flow competence. Appendix A presents thorough discussions on dimensions, units, and numerical precision. In lieu of problems or exercises, Dingman provides online spreadsheets for flow databases, synthetic channel hydraulics, and water-surface profile computations. These spreadsheets are described in Appendices B, C, and D. I was unable to reach the website at the URL included in the text, but found the spreadsheets at this URL by searching the publisher’s website: http://www.oup.com/us/companion.websites/9780195172867/?view=usa. I was unable to find the links to other fluvial geomorphologic websites or discussion pages noted in the introduction. The book will be useful for an undergraduate-level or graduate-level class in channel hydraulics and morphology, for students with an understanding of basic calculus and university-level physics. For civil engineers, the book is a valuable companion to classic open-channel texts because it includes extensive discussions and applications focused on natural streams. For researchers, practitioners, and students in the natural-resources sciences, the book provides clear and complete discussions of open-channel flow that do not require a theoretical background in fluid mechanics to understand. This book will spend more time on my desk than on my shelf; I will refer to it often. Katherine J. Chase, PE 541 Diehl Dr. Helena, Montana 59601 The World’s Water: 2008-2009, The Biennial Report on Freshwater Resources , P.H. Gleick with H. Cooley , M.J. Cohen , M. Morikawa , J. Morrison , and M. Palaniappan . Island Press , 1718 Connecticut Ave. NW, Ste. 300, Washington, D.C. 20009 . 2008 . 402 pages. $35 . ISBN 978-1-59726-505-8 . The First Biennial Report on Freshwater Resources for the world by Peter H. Gleick was issued in 1998. The Sixth Biennial Report by Peter H. Gleick and his associates is the latest version and covers the period 2008-2009. The series continues to be an invaluable collection of all kinds of water-related material, ranging from concise stand-alone chapters on important topics to numerous sections of data that have been updated as much as possible given the mix of reporting countries. A sampling of some of the six discussion chapters that are at the beginning of the book of 402 pages should provide the reader a good sense of the nature of the material. The first chapter by M. Palaniappan and P. H. Gleick on “Peak Water” provides an interesting discussion of the similarities and differences between oil and water. The importance of ocean water desalination is that the amount is unlimited, but the problem is how much we are willing to pay for it. In areas where water is really scarce, such as selected islands in the Caribbean and certain parts of the Persian Gulf, desalination is already becoming an “economically competitive alternative.” Chapter 2 on “Business Reporting on Water” by M. Morikawa, J. Morrison, and P. H. Gleick provides a useful accounting of corporate reporting of non-financial environmental information in annual reports that started in the 1970s. These non-financial reports have grown from fewer than 50 in 1992 to over 1,900 in 2005 and 2,470 by 2007. As expected, water management and use reporting by major corporations vary from industry to industry. In addition, and regrettably, most corporations rarely report on water recycling and reuse. The next chapter by H. Cooley deals with water management in a changing climate. A sampling of some of the water resource issues associated with climate change include the following: (1) climate change will affect the quantity and timing of surface runoff, (2) groundwater is less understood than surface water and sea level rise could result in greater saltwater intrusion in coastal aquifers, and (3) agriculture accounts for 70-80% of global water use and lawns in hot, dry areas can account for 70% of total residential water use. Even in developed countries, water infrastructure that was designed and operated on historic water conditions may become a problem in the future. In 2002, 1.1 billion people did not have access to improved water supply and 2.6 billion did not have access to improved sanitation. Of particular interest is the section from pages 151-193 by P. H. Gleick pertaining to the chronology of water conflicts from Noah’s flood of about 5,000 years ago to fights between animal herders and farmers in Burkina Faso, Ghana, and Cote D’Ivoire in 2007 in the Sahel region of West Africa just south of the Sahara Desert. a description of the of the the and the It is clearly a valuable on the world history of water conflicts that are not in number and of this book is the of that on pages A sampling of these data include information on water and use by data on access to water and updated on in Africa and the information on in five years of from water-related and data on the of water in selected countries and In this book is as an excellent of information on the world’s It is well and includes an extensive on a of water-related It is a for interested in the water resource Robert M. Water Resources New A of the of 2008 , ( ). University of Press , . . pages. . ISBN . 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The present study attempts to assess the nature of effluents generated from textile bleaching and dyeing units located at Kalikapur area under Maheshtala region, West Bengal, India and to provide a sustainable management of ground water resources through installing CETPs with zero liquid discharge system. Effluent from medium, small and tiny units of this region is estimated at 2000 MLD. Studies with 40 units for 4 years (2012—2016) located in this area exhibited following mean values of different physic-chemical variables: pH (9), Biological Oxygen Demand (610 Mg/L), Chemical Oxygen Demand (1827 Mg/L), Total Dissolved Solids (6411 Mg/L), Total Suspend Solids (927 Mg/L) and toxic metals such as lead Pb (0.43 Mg/L), Chromium (0.031 Mg/L), Zinc (0.74 Mg/L), Nickel (0.07 Mg/L) and Cadmium (0.03 Mg/L). These finding of results surpass the standard allowable limits qualify by FAO (1985) and World Health Organization (2003). The waste water loaded with toxic trace metals is adversely affecting the environmental pollution and anthropomorphic eudemonia and also pollute the quality of both surface and ground water and consequently degraded agricultural and plant yield, vegetable and fruits and causes impairment to aquatic lives. Four to five Common Effluent Treatment Plants are urgently required to install at different areas of the Maheshtala cluster with a capacity of 500 MLD each, so that one in Kalikapur area, to manage sizeable volume of waste water (2000 MLD) and sustainable management of ground water resources in a thickly populated urban area near Calcutta, a principal city of India.

Transforming groundwater sustainability, management and development through deep learning

Groundwater resources plays important role in agro-biodiversity and environmental conservation perspectives. Surface and groundwater have played a significant role in the agrarian economics in the developing economics particularly in India. At the same time, the tropical and sub-tropical India is the largest groundwater user in the world through unregulated construction and utilization of millions of private wells in the last five decades exploited groundwater availability and sustainable regeneration issues. Hence, in order to improve the surface and groundwater conservation, regeneration, management and protection for sustainable utilization of Groundwater requires a participatory and coordinated action. Nationwide, many national and regional Non Government Organisations (NGOs) are functioning in the line of effective surface and ground water management the community. The recent Geographical Information Systems (GIS) based technologies also supports for drought mitigation and climate change adaptation. This study highlights the important NGOs led sustainable Groundwater management practices under various local hydro geological settings and agro economic realities for up scaling the community driven sustainable Groundwater management.

Meeting people's water supply needs in cities is an urgent challenge. Especially in coastal cities, surface water sources are usually inadequate and so groundwater is frequently over-exploited, resulting in its rapid decrease and intrusion of saltwater. Conjunctive use of surface water and groundwater is the best alternative approach to mitigate the overuse of groundwater through effective distribution of surface water sources. It requires numerous runs of the simulation-optimization model to select an optimal pattern of water distribution by keeping the groundwater levels under control. In this study, a new simulation-optimization model is developed using wavelet support vector regression (WSVR) and genetic algorithm (GA) to propose an optimal water distribution system to Visakhapatnam city on the East Coast of India, fulfilling the constraints of surface water quantity, aquifer pumping, and drawdown. Estimation of groundwater pumping and groundwater level variation in spatial context is challenging in urban environment. To overcome this, the calibrated modular finite-difference flow (MODFLOW) model for this study area has been used to prepare the spatial and temporal variation of model inputs such as groundwater pumping and groundwater levels. The WSVR-GA model's performance to reduce the groundwater pumping is evaluated in three distinct cases. The surface water resources from three sources are distributed to different wards in the city source-wise in case I and centralized in cases II and III, while the source-wise surface water constraints are limited to monthly in cases I and II and annual in case III. The WSVR-GA management model suggested ward-wise groundwater pumping restrictions, resulting in 9.57 MCM, 11.64 MCM, and 12.54 MCM increase in total groundwater storage capacity in cases I, II, and III respectively. Cases II and III offer 21% and 25%, respectively, more storage than case I. Thus, centralized distribution systems have increased the sustainability of groundwater supplies by preventing overdrafts caused by a lack of surface water resources. Validation of results using MODFLOW indicates a substantial rise in groundwater levels in the study area.

<p>While climate change will challenge the future of California’s water resources, groundwater can buffer variability in precipitation and streamflow, if managed sustainably. Enhanced river recharge is an important tool to reach sustainable groundwater management in the California Central Valley (USA). Understanding and predicting recharge rates of river water, either natural river bank infiltration or managed aquifer recharge (MAR) during floods (Flood-MAR) or on agricultural land (Ag-MAR) is essential to evaluate the sustainability of groundwater management plans. Groundwater ages, combined with other isotopic and noble gas evidence, can elucidate surface water-groundwater interactions and support river recharge rates calculations over longer time periods.</p><p>Our study is focused on the recharge from the Cosumnes River in the California Central Valley. The Cosumnes River forms the boundary between the Sacramento Valley groundwater basin to the north and the San Joaquin Valley groundwater basin to the south. For this study, 28 new samples were collected for the analysis of 3H/3He age, noble gases, and stable isotopes. 25 additional samples from the California Waterboards Groundwater Ambient Monitoring and Assessment (GAMA) Shallow Aquifer Assessment program were included, which were collected and analyzed by the USGS California Water Science Center in 2017.</p><p>We find that 28% of groundwater in the San Joaquin – Cosumnes groundwater subbasin originated as river water recharge, based on the interpolated mean δ<sup>18</sup>O (7.7 ‰ ), compared with river water (-9 ‰) and local precipitation recharge (-7 ‰) end-members. River water is a source of modern recharge, resulting in high tritium concentrations close to the Cosumnes River. In contrast, ambient groundwater from local precipitation recharge is predominantly pre-modern or fossil, containing less than 1 pCi/L tritium. Combining groundwater ages with the distance to the river, aquifer thickness, and porosity, estimates of river water recharge rate vary between 0.02 km<sup>3</sup>/yr and 0.035 km<sup>3</sup>/yr. These quantitative estimates of river water recharge will constrain the numerical groundwater flow model for this basin and aid groundwater managers in developing sustainability plans to balance groundwater pumping with recharge rates.</p>

The SUDOE AQUIFER project (http://www.igme.es/aquifer/) aims at capitalizing, testing, diffusing and transferring innovative practices for groundwater monitoring and integrated management.BRGM has developped the « MétéEAU Nappes » web platform (https://meteeaunappes.brgm.fr/fr) for several years. It enables to visualize the current and future behavior of groundwater bodies in France and to forecast groundwater availability in many monitoring wells which have been modeled using a lumped hydrological model [1].Although more than 500 wells are monitoring groundwater level in real time in unconfined aquifers in the Adour-Garonne basin (France) (https://ades.eaufrance.fr/), none of these monitoring points have been modeled to enable 6 months groundwater levels forecast. The SUDOE AQUIFER project enables to model ten monitoring points in 2022 and 2023 to forecast groundwater levels using different climatic scenarios. These forecasts are updated on a monthly basis and can be compared to groundwater levels thresholds (piezometric drought thresholds from local authority use-restriction orders [2]).These groundwater level forecasts are further used to predict groundwater withdrawable volume using a three-dimensional groundwater flow model in the Garonne, Tarn and Aveyron alluvial plain [3]. The main activity of this region is agriculture and the main groundwater use is crop’s irrigation. Groundwater withdrawal is especially important in the summer, and can impact the volume of groundwater reaching the rivers and sustaining their baseflow. This competition in use creates the need to accurately define potential withdrawable volumes.Combining the lumped hydrological models with a three-dimensional groundwater flow model enables to define the potential withdrawable volume based on (1) the summer climatic scenario chosen by the decision maker, (2) the forecasted groundwater level at the end of the low-water season and (3) the status of the groundwater body (critical, balanced, conservative) to achieve at the end of the low-water season. This decision support tool is developed as a web platform and will be accessible to groundwater managers and decision makers. After choosing the groundwater level forecasted at the start of the irrigation period within 6 scenarios based on different climatic conditions, three potential withdrawable volumes will be defined depending on the status of the groundwater body considered acceptable to obtain at the end of the low-water season. This information can then be communicated to groundwater users.These innovative practices will be extended to other regions where increase groundwater pressure forces local authority to develop methods and tools to sustainably manage groundwater bodies.Références bibliographiques : [1] Mougin B., Nicolas J., Vigier Y., Bessière H., Loigerot S. (2020). « MétéEAU Nappes » : un site Internet contenant des services utiles à la gestion des étiages. La Houille Blanche, numéro 5, p. 28-36. https://doi.org/10.1051/lhb/2020045[2] Surdyk N., Thiéry D., Nicolas J., Gutierrez A., Vigier Y., Mougin B. (2022). MétéEAU Nappes: a real-time water-resource-management tool and its application to a sandy aquifer in a high-demand irrigation context. Hydrogeology Journal. https://doi.org/10.1007/s10040-022-02509-1[3] Le Cointe, P., Nuttinck, V., Rinaudo, JD. (2020). A Tool to Determine Annual Ground-Water Allocations in the Tarn-et-Garonne Alluvial Aquifer (France). In: Rinaudo, JD., Holley, C., Barnett, S., Montginoul, M. (eds) Sustainable Groundwater Management. Global Issues in Water Policy, vol 24. Springer, Cham. https://doi.org/10.1007/978-3-030-32766-8_13

We investigate the seasonal variations of ion precipitation, utilizing observations from the Mars Atmosphere and Volatile Evolution mission spanning from 2014 January 4 to 2023 February 14. Our analysis reveals that a diminishing pattern characterizes the transition from Mars season L s 0°–180° to Mars season L s 180°–360°, manifesting as a reduction in precipitating ion fluxes. Additionally, we discern a significant influence of the crustal magnetic field on the seasonal variations in precipitating ion fluxes. Intriguingly, within regions where the crustal magnetic field exhibits a strong quasi-horizontal orientation, opposite seasonal trends become evident. The underlying physical mechanism driving these seasonal variations in ion precipitation is probably attributed to the mass loading effect that may decelerate the solar wind and influence the magnetic pileup. A detailed investigation is further demanded in the future.

Groundwater is a critical supply of freshwater in Africa, providing safe drinking water near to where it is needed for homes, agricultural, and industrial uses. Due to the high vulnerability of surface water resources to anthropogenic activities and climate change, groundwater consumption has increased dramatically over the last 50 years and is likely to continue rising in future. This study examines the effect of rainfall variability on groundwater levels using rainfall and groundwater level fluctuation data from Nzoia River Basin, Kenya. A cross-sectional survey design was used. Three counties were randomly selected from the basin for study with Busia representing the lower catchment, Kakamega middle catchment and Trans Nzoia upper catchment. Groundwater is the main drinking water resource in the basin supplying 78.8% of the population. Knowledge of long-term rainfall variability and the associated response of the basin’s groundwater resources are essential for efficient and sustainable groundwater management. Despite the relatively short period for which water level records are available, these records contain valuable information that can be used beneficially in the development of strategies to assist in the responsible management of our limited groundwater resources. Rainfall and groundwater levels were analysed using the parametric test of linear regression and the non-parametric Mann–Kendall statistical test. Rainfal data for this study was obtained from the Kenya Meteorological Department (KMD) and the Groundwater levels from Kenya Water Resources Management Agency (WRMA). Pearson moment correlation was used to check the relationship between monthly rainfall and monthly groundwater levels. Correlations between groundwater levels and rainfall will help assess aquifer vulnerability to climate change in the basin. Our results indicate that rainfall variability induced by climate change has greatly impacted groundwater levels in the basin. Annual groundwater levels have been steadly falling at the rate between 0.03 ft/year (Kakamega Tande School) and 0.49 ft/year (Kitale Golf Club) in the basin. Annual rainfall over the basin has shown stations recording both decreasing and increasing trends. The falling groundwater level trends indicate a cause for concern and provide a scientific basis for the national and county governments in the basin to strategize on ground water development and management for sustainable water use.

Sustainable groundwater management is critical in semi-arid regions, where competing demands from agricultural, urban, and industrial sectors strain water resources. California and Catalonia share a Mediterranean climate, where the peak growing season coincides with the driest months, necessitating significant reliance on stored water for irrigating agriculture. Here, we examine the science-policy interface in groundwater management by comparing Catalonia, Spain, and California's Central Valley—regions possessing similar climatic pressures but having developed distinct regulatory frameworks under differing hydrogeological contexts.California's Central Valley is characterized by a vast, deep sedimentary aquifer system that supports the largest agricultural economy in the United States. However, over-extraction has led to domestic and agricultural wells running dry, severe land subsidence, and widespread nitrate contamination. In contrast, Catalonia's aquifers are generally smaller, shallower, and are more susceptible to saltwater intrusion from the ocean. In 2014, California passed the Sustainable Groundwater Management Act (SGMA), representing a shift towards regulated groundwater use. However, the state’s complex water rights system—featuring separate allocation frameworks for groundwater and surface water—combined with the immense scale of the Central Valley Aquifer system, complicates the effective implementation of SGMA and its goal of sustainable groundwater management. Conversely, Catalonia, guided by the EU Water Framework Directive of 2000, has adopted an integrated approach to groundwater and surface water management within a unified framework that emphasizes public supply and sustainability.We analyze the contrasting approaches of these two regions to explore what each can learn from the other’s management strategies. For California, Catalonia highlights the importance of treating groundwater and surface water as a single, interconnected resource within a unified regulatory framework. This demonstrates how conjunctive water regulation can improve long-term resource sustainability. Conversely, California’s extensive monitoring networks, basin characterization programs, and advancements in data collection offer valuable tools that could enhance Catalonia’s water management efforts. By focusing on these lessons, we aim to underscore how shared insights can inform more effective water governance in distinct hydrogeological and regulatory contexts.This comparative analysis highlights the critical role of understanding the hydrogeological context in shaping blue diplomacy policies. It underscores the importance of interdisciplinary approaches, such as leveraging diplomatic tools and scientific expertise to address water security challenges and build resilience to climate extremes in semi-arid regions globally.

The aim of this work is to determine the variability of precipitation in the area of the sub-basin of the South Curve up to the hydrological station Korvingrad. Data from the synoptic stations Leskovac, Vranje and Kuršumlija for a period of 30 years (1991-2020) were used. The mean relative variability of monthly, seasonal and annual precipitation and their ten-year values were used to compare the results of all synoptic stations in the sub-basin. The results showed that the highest mean variability of precipitation in the studied period was recorded at the Vranje synoptic station (22.4%) and the lowest value at the station in Leskovac (18.4%). The comparison of ten-year values showed that the lowest values of mean relative variability of annual precipitation in the period 2001-2010 were recorded at all synoptic stations. The study showed that the extreme values of mean relative variability of precipitation occurred earlier or later during the second and third ten-year periods compared to the first ten-year period. The study showed that the values of mean relative variability of monthly precipitation were lowest in months with high precipitation.

Long-term population growth and economic development are placing ever-increasing pressure on South Africa's freshwater supply. On the basis of the current climate change predictions, which often entail uncertain consequences for aquifer systems and the associated groundwater goods and services, it is expected that the stress on water will increase even further. Currently, South Africa's groundwater governance regime does not provide the capacity to assure effective and sustainable resource regulation and allocation. To date, the management of groundwater is hampered by a variety of uncertainties, such as global climate change and socio-economic growth, as well as ineffective governance structures affecting resource use, regulation, protection and the implementation of alternative strategies needed to achieve sustainable management. This paper presents the results of a qualitative assessment of interviews conducted with experts in South Africa. Four key challenges are identified to the development of adaptive and sustainable groundwater management and the successful implementation of current water legislation in South Africa. These are: the undervaluation of groundwater importance and significance; the need for expertise and information at all scales; the centralisation of power; and the disregard of ecosystems and the associated goods and services. As a means to tackle these challenges, it has been assumed that the concept of adaptive water management represents a suitable approach to governing groundwater resources, by taking into account complex system linkages between hydrogeological, political, socio-economic and environmental domains. Supporting principles, such as tools for cooperation, participation and information networks, have been developed to facilitate the implementation of adaptive water management approaches and hence to achieve institutional change in the political arena of groundwater management.Keywords: groundwater, South Africa, ecosystem services, adaptive water management, qualitative assessment

The DIALAQ project on sustainable groundwater management: a transdisciplinary and transcultural approach to participatory foresight