Groundwater in Developing Countries

Inhaltsverzeichnis

1. Frontmatter

2. Chapter 1. Fluoride Contamination, Health Effects, and Defluoridation Techniques in Groundwater-Dependent Developing Countries

   Shaz Ahmad, Shakir Ali, Kiana Modaresahmadi, Reena Singh, Krishna Neeti

   Abstract

   Fluoride (F^–) contamination in groundwater has received significant attention in recent decades owing to its toxicity to humans. Although referred as a “double-edged sword”, F^– in a lower amount prevents dental caries while an excessive amount of F^– induces irreversible dental and skeletal fluorosis and is thus detrimental. Therefore, this study was conducted to investigate sources, health effects and defluoridation techniques in various developing countries where the problem is severe. The study revealed that (1) F^– contamination in groundwater is widespread and mostly found in arid and semi-arid regions in developing nations. (2) F^– in groundwater is primarily influenced by F^–-bearing aquifers, prevailing geological and meteorological conditions, longer rock-water interaction, and ion-exchange reactions. (3) Many developing countries are struggling to meet the F^– standards set by the WHO due to lack of knowledge and constraints. The study documents the extent of F^– contamination, its potential origins, remedial strategies/defluoridation techniques and various projects/programmes for defluoridation in developing countries. The study emphasizes the need to extent research on more effective and affordable defluoridation methods for both individual households and community water supply systems. Finally, the study also highlights various challenges and suggests future research paths to address elevated F^– concentration in achieving the UN’s sustainable goal of providing safe drinking water.

3. Groundwater in MENA Regions

   1. Frontmatter

   2. Chapter 2. Groundwater Storage Variations in the MENA Transboundary Aquifer Systems Using GRACE: Response to Global Climate Change

      Hussein A. Mohasseb, Abdelazim M. Negm, Shuang Yi, Wenbin Shen

      Abstract

      This study delves into the sustainability of Groundwater Storage (GWS) in three major Middle East and North Africa (MENA) aquifers—the Nubian Sandstone Aquifer System (NSAS), North Western Sahara Aquifer System (NWSAS), and Murzuk Aquifer System—using Gravity Recovery and Climate Experiment (GRACE/GRACE-FO) and Global Land Data Assimilation System (GLDAS) data from January 2003 to December 2021. The NSAS, spanning multiple countries, experiences substantial GWS decline linked to reduced precipitation, rising temperatures, and increased evapotranspiration (ET). The NWSAS faces significant GWS depletion due to limited precipitation and elevated ET, highlighting hydrological challenges. In the Murzuk Aquifer, GWS exhibits a dual-stage decline exacerbated by changing climate conditions, declining precipitation, and equilibrium between precipitation and ET. These findings emphasize the MENA region’s need for proactive water resource management and climate change adaptation. For example, NSAS experiences alarming GWS depletion at − 1.28 ± 0.22 mm/year post-2009, while Chad sees positive GWS trends at 0.41 ± 0.04 mm/year due to higher annual precipitation. In the NWSAS, the substantial GWS depletion with a trend of − 3.62 ± 0.70 mm/year is attributed to low yearly mean precipitation of 84.48 ± 0.83 mm/year and high ET of 83.52 ± 0.97 mm/year. In the Murzuk Aquifer, GWS depletion sharply declines at − 2.41 ± 0.65 mm/year post-2010, emphasized by low annual precipitation of 30.12 ± 0.25 mm/year and elevated ET of 25.68 ± 0.33 mm/year. Despite relatively constant precipitation rates, there is a noticeable rise in groundwater depletion, indicating increased reliance on groundwater due to human activities in the MENA region.

   3. Chapter 3. Groundwater Management and Governance in MENA Region

      Mohamed A. Dawoud

      Abstract

      The Middle East and North Africa (MENA) region is an arid and hyper arid region with nineteen countries/states with annual renewable freshwater per capita below water scarcity threshold (1000 m³/year). Groundwater is a key resource in the MENA region for improving water supply and agriculture uses. Due to the scarcity of renewable freshwater, increasing demand, and stress on surface water, nearly twelve states primarily depend on groundwater as a primary source of freshwater. Groundwater resources account for more than 80% of freshwater withdrawals in six states. There are 43 transboundary aquifer systems within the region. About 50% of the MENA region’s aquifer systems are non-renewable with over-abstraction which lead to sever drop in water table and deterioration in groundwater quality. In eight states, about 85% of agriculture irrigation water comes from groundwater compared to a global average of about 35% which also affects the food security. This is exacerbated by low water use productivity within the region with an average of about $0.25/m³ compared to $0.68/m³ globally. Groundwater valuation studies indicating that the economic value of groundwater is some states ranges between $0.52 and 0.85/m³. Economic valuation of groundwater supports planners and decision-makers in allocating and prioritizing available limited water resources in different developing sectors. Also, it will help in comparing between investing in groundwater protection with other environmental matters, and in balancing groundwater withdraw with conservation it for future generations. This chapter will assess how groundwater declining and deterioration due to increased demands, inefficient use and impacts of climate change should prompt MENA states to explore innovative and integrated governance frameworks to improve the management and ensure equitable access to strategic resources for both current and future generations. The groundwater importance for water security in the region should enhance the use of innovative technologies and dedicated funding towards integrated water resources management and heightened regional cooperation. Many countries in the region started to regulate groundwater resources with emphasis on allocation, well drilling, licensing, metering and sometimes pricing. However, the enforcement of these regulations is still weak. The depletion and quality deterioration of many aquifers are increasing the abstraction costs which affecting the social differentiation, as smaller farmers are pumped out and foreshadows a gradual collapse of the groundwater economy within the region. Few countries in the region still subside the groundwater abstraction which also affects the sustainability of this limited resource.

   4. Chapter 4. Potential of Using River Bank Filtration to Augment Water Resources: A Review

      Zeinab M. El-Fakharany

      Abstract

      Global demand for high drinking water quality is increasing due to urbanization and population growth. Riverbank filtration (RBF) is a green water treatment mechanism that extracts water from rivers by nearby pumping wells, where it is purified through natural physical, biological, and chemical reactions that take place through the aquifer porous media. RBF, as a green water treatment mechanism, can reduce contaminant concentrations to standard limits. RBF has been used extensively in Europe for over a hundred years along the Elbe and Rhine rivers for domestic water production. Nowadays, the application of this technique has been extended throughout the world. It ensures natural, sustainable water quantity, improves surface water quality, and is cost-effective. RBF wells types include vertical, horizontal, and infiltration galleries. Hyporheic zone, a biologically active layer formed from sediment accumulation and fine-grained particles, is important for the filtration and attenuation of natural contaminants. It removes suspended solids, turbidity, heavy metals, biodegradable compounds, pathogenic bacteria, and pharmaceutical wastes from river water, as well as partial attenuation of organic compounds and pesticides. Layer erosion has regenerative effects that restore infiltration rates. RBF is site-specific, and every site requires detailed comprehensive investigations for both aquifer and river characteristics. Groundwater flow modelling is used to identify the optimum well location and predict travel time. Previous applied practices support RBF as an appropriate alternative to conventional treatment plants for drinking water production with low cost before disinfection. RBF has socio-economic values, increasing per-capita availability of drinking water and protecting public health. This article reviews the potential of RBF to augment water resources.

   5. Chapter 5. Integrating MODFLOW-USG and Walrus Optimizer for Estimating Sustainable Groundwater Pumping in Arid Regions Subjected to Severe Drawdown

      Ahmed M. Saqr, Mahmoud Nasr, Manabu Fujii, Chihiro Yoshimura, Mona G. Ibrahim

      Abstract

      Aquifer depletion due to excessive groundwater use is a global issue that should be adequately addressed to avert the associated severe consequences. Thus, the MODFLOW-USG model was integrated with the walrus optimizer (WO) to form a novel simulation–optimization (S–O) framework for promoting sustainable groundwater management, particularly in water-scarce areas. The MODFLOW-USG/WO framework was applied to the Egyptian region, namely Wadi El-Natrun, which is experiencing declining groundwater levels. The MODFLOW-USG model was calibrated, leading to high accuracy in simulating groundwater levels with a correlation coefficient of ~1. Besides, the existing groundwater extraction rate was about 0.227 million m3/day (current situation), resulting from flow budget analysis. Two scenarios were examined to simulate the variation in groundwater levels by increasing the current situation by 20% (scenario No. I) and 40% (scenario No. II). Both scenarios predicted significant groundwater level declines by 2030, especially in the basin’s southwest. The research study then combined MODFLOW-USG with WO, outperforming other methods, while testing a hypothetical aquifer problem. Using this integrated S–O framework, extraction rates of 0.259 and 0.291 million m³/day, representing 114% and 128% of the current situation, were obtained to guarantee median drawdown values across the basin, respectively. The suggested S–O approach developed in this research study has potential applications beyond the Wadi El-Natrun basin. It could be a valuable tool for managing groundwater resources efficiently in similar regions across the globe, contributing to the achievement of sustainable development goals (SDGs).

   6. Chapter 6. Hydrochemical Assessment of Groundwater of Kingdom of Saudi Arabia Based on Deterministic and Integrated-Weight Water Quality Index Models

      Othman Fallatah, Mahmoud R. Khattab

      Abstract

      Extreme natural and anthropogenic activities have dangerously deteriorated groundwater quality throughout the world. To disclose the quality of groundwater, contaminants sources and human health risks in the Kingdom of Saudi Arabia (KSA), huge groundwater samples (higher than 700) were collected for this study and used for comprehensive evaluation of the groundwater quality and potential risks of F⁻, and NO₃⁻ to human health for the first time in KSA. We found that F⁻, and NO₃⁻ vary spatially, and the concentrations of F⁻, and NO₃⁻ are varied between 0 mg/L to 4.5 mg/L (mean: 0.54 mg/L), and 0 mg/L to 133 mg/L (mean: 18.6 mg/L), respectively, and are higher than the recommended limits of WHO in numerous drinking wells. Results of the irrigation water quality index (IWQI) exhibited that F⁻, NO₃⁻, Cl⁻, and SO₄²⁻ have greater effects on humans in the investigated area. Hydrochemical evolution in the groundwater is primarily compelled by both rock-water interaction and anthropogenic influences. Potential health risk results showed that the oral intake pathway would pose potential non-carcinogenic risks to adults and children than the dermal pathway. The human health risk assessment indicated that non-carcinogenic risks posed by F⁻, and NO₃⁻ were high for children than adults. The outcome of this study indicated that rational measures should be preferred to protect the groundwater quality in context of achieving UN sustainable development goal.

   7. Chapter 7. Groundwater Sustainability in Arid Regions Using Environmental Isotopes Hydrology Cursors

      K. Hagagg

      Abstract

      Groundwater resources are considered as the key to all human activities and their survival adaptation, particularly in arid regions. Decision makers have special ambitious goal of optimal groundwater resources using with limited undesirable impacts both presently and in the future. Hence, groundwater development projects depend mainly on the ability to manage the resources and to protect their quality and quantity and utilize them efficiently. In this context, different approaches have been discussed in this chapter. Results shows that the developed indices for water resources sustainability are among the simplest used approaches that are based on a wide scale of hydrogeological and social indicators. On the other hand, numerical models can be used, as a powerful tool in the management plans and prediction of groundwater behaviour. In this chapter, retrieved approaches from different regions have been discussed based on the understanding of recharge, storage, and discharge mechanisms as being important for strategic freshwater resource. This chapter highlights the importance of understanding groundwater renewal, quality, and transport by way of numerous approaches, of which isotope hydrogeology is one of the potential approaches. Therefore, more emphasises on application of isotope hydrology approach and its conjugation with other approaches will help in providing a rapid and accurate understanding of the groundwater systems and characterizing its regime. In addition to that, it would also help in estimation of an accepted logistic framework that might help in controlling and even evaluating the significance of predicted climatic and anthropogenic impacts on groundwater resources.

   8. Chapter 8. Groundwater in Southern Algeria Provinces: Challenges and Strategies

      Zegait Rachid

      Abstract

      The Southern Algerian Aquifer System comprises two main deep aquifer layers: the Continental Intercalary Formation and the Terminal Complex Formation. These aquifer layers cover an area of more than 700,000 km² in Algeria. Due to desert-like climatic conditions, these formations are poorly recharged, with approximately 1 billion cubic meters (BCM) of water infiltrating annually, mainly in the mountainous regions of the Saharan Atlas. The Saharan Aquifer System is exploited through over 6500 water points, including boreholes and springs in the Continental Intercalary and Terminal Complex formations. Over the past two decades, there has been an exponential growth in the number of boreholes and the frequency of their use, now reaching 1.33 BCM per year. If this trend continues, it could raise serious concerns about the future of Saharan regions, where the initial signs of declining water availability are already evident. The rapid expansion of exploitation of the southern Algerian aquifers has fundamentally altered the perception of this activity. However, this expansion faces several significant risks associated with its development, including water salinization, loss of artesian pressure, depletion of outlets, and excessive pumping levels. Therefore, sustainable management of this vital resource is imperative, incorporating appropriate management practices and implementing regulations to prevent overexploitation and adverse impacts on the aquifer ecosystem. Despite the limited recharge, the scale and the aquifer thickness have led to the accumulation of considerable water reserves. This chapter aims to comprehensively investigate the methods employed for groundwater utilization in southern Algeria, with a dual focus on elucidating existing issues and confronting contemporary challenges. It aims to examine approaches for enhancing and rationalizing the extraction of water from Saharan aquifers to promote regional advancement, all the while prioritizing the preservation of long-term sustainability.

   9. Chapter 9. Groundwater Mapping of the New Delta Area (West of Nile Delta) Using Geographic Information Systems and Satellite Images

      Salwa Elbeih, Elsayed Zaghloul, Mohammed Hagage, Wael Attia, El-Sayed Abdelsadek, Ahmed El-Okbi, Joseph Khalil

      Abstract

      To ensure that groundwater is used in a sustainable manner, it is necessary to map, monitor and protect groundwater aquifers. Water scarcity is one of the most pressing global challenges of the twenty-first century that affects billions of people worldwide. One of the main challenges facing sustainable development in Egypt is the need for better growth and management of its limited freshwater resources. In Egypt, groundwater exists in the fringes of the Nile Valley, Nile Delta, Western Desert, and Sinai Peninsula. Groundwater Mapping is one of the main tools for groundwater exploration and one of the key components in strategic development projects. The hydrogeological map shows the geographical distribution of aquifers and their topographical, hydrogeological, hydrographical, hydrological and hydrochemical features. This chapter mainly presents the hydrogeological mapping for the New Delta Region (The Western Extension of Alexandria Region in the Western Desert) illustrated in Al-Qahirah and Al-Alamayn map sheets, scale 1:250,000. Nine main layers are illustrated for the area under investigation. The layers are: hydrogeological units, lithological units, surface water, man-made features, groundwater features, topographic features, base of aquifer map, isopiezometric and isosalinity contour lines. In addition, descriptive text and land use maps for each map sheet are added to provide more illustrations and descriptions of the groundwater characteristics in the study area as well as the climatic conditions.

4. Groundwater in Asia

   1. Frontmatter

   2. Chapter 10. Challenges Faced by Closed Basins from the Perspective of Water Resources: Case Studies from Türkiye

      Nilüfer Tirol Kırçiçek, Esra Bilgiç Güngör, Alper Baba

      Abstract

      Closed basins form important hydrological systems that provide a variety of benefits to both the environment and humans. This chapter examines the current status of closed basins in Türkiye and analyzes the natural and anthropogenic environmental stressors affecting these regions. Two distinct case studies are covered in this chapter: the Konya Closed Basin (KCB) and the Karakuyu region. Konya Closed Basin has experienced severe drought and sinkhole issues as a result of misapplications and excessive water consumption. The severity and frequency of water-related problems are increasing day by day due to the impact of climate change in the region. Agricultural activity and irrigation needs are high in the Karakuyu region, which is considered a second case study and is a small part of the Küçük Menderes River Basin. It is hoped that with improved management practices, Karakuyu will not experience the condition of KCB in the future. The final section outlines the recommended practices and precautionary measures for addressing issues associated with closed basins.

   3. Chapter 11. Issues and Challenges in Sustainable Usage of Groundwater Resources in Afghanistan

      Abdulhalim Zaryab, Aref Nazari, Asadullah Farahmand, Mohammad Saber Yaqubi, Sayed Mohammad Mansoor Mirzad, Zamen Jafari, Mohammad Tamim Ibrahimi, Hamid Zaki, Shakir Ali, Ajmal Khan Shams

      Abstract

      Globally, Afghanistan is currently a frontrunner in groundwater scarcity due to unplanned urbanization, rapid rise in population, climate change, weak policies, mismanagement, and lack of long-term vision. Frequent weather extremes like droughts and floods and prolonged war and political instability lead the country far away from achieving water security, food reliance and sustainable management of its natural resources. The war situation also refrains in gathering of long-term hydrological data and thus, there is a huge gap in understanding the water resources even better. Furthermore, aids from international organizations are limited in groundwater development and management. This chapter highlights various issues and challenges in sustainable usage and the importance of groundwater in the country. The chapter compiles the research carried out with regard to Afghanistan’s quest to manage its groundwater resources more efficiently.

   4. Chapter 12. Optimization of the Location of Groundwater Intakes for Irrigation and Melioration Purposes in a Typical Intermountain Chu Valley, Kyrgyzstan: Analytical and Model Approaches

      Rafael G. Litvak, Ekaterina I. Nemaltseva, Aman Ch. Imanaliev

      Abstract

      This chapter contains the results of research conducted on the Chu Valley in Kyrgyzstan. The territory is a typical intermountain valley, including the following hydrogeological zones: recharge, discharge, transit and regional discharge of groundwater. The placement of additional irrigation groundwater intakes should be made taking into account the possible melioration effect, the essence of which is a decrease of groundwater levels below a critical depth. This will reduce groundwater evaporation and prevent soil salinization processes. The largest areas of flooded territory are located in the discharge zone. However, the location of water intakes in this zone without scientific justification does not always provide the proper melioration effect. The chapter presents the analytical criteria obtained by the authors for the rational location of groundwater intakes. The specified criteria are compared with the results of groundwater modeling obtained using the MODFLOW software package. The comparison showed the possibility of using the proposed relatively simple analytical criteria for optimization of the location of groundwater intakes in the typical intermountain valleys.

5. Groundwater in West Africa

   1. Frontmatter

   2. Chapter 13. Groundwater Development Within the Nigerian Crystalline and Sedimentary Aquifers: Challenges and Opportunities

      Johnbosco C. Egbueri, Johnson C. Agbasi, Leonard N. Onuba, Nchekwube D. Nweke, Henry C. Uwajingba, Sani I. Abba

      Abstract

      This chapter explores the geological, hydrogeological, geophysical, contamination, and socio-economic aspects of groundwater resources in Nigeria, highlighting the challenges and opportunities related to their exploration, exploitation, and management. Nigeria’s groundwater resources are predominantly sourced from two major hydrogeological terrains—the basement complex covering around 50% of the nation’s landmass and sedimentary terrain spanning the other 50%. The basement complex hosts aquifers within weathered and fractured crystalline hard rock formations, including regolith/overburden aquifers, fractured basement aquifers, and deeper fracture zones. While generally low-yielding with limited storage capacity, localized high groundwater yields can be obtained from highly fractured or deeply weathered zones. In contrast, the sedimentary terrain features are more productive multi-layered and discontinuous aquifer systems within the basins like Chad, Sokoto, Benue Trough, Anambra, Dahomey, and Niger Delta basins, and characterized by higher yields and larger storage potentials. The aquifers within these basins are explored and exploited using a wide range of techniques, including geological, hydrogeological, hydrogeophysical, remote sensing, and geographic information system tools. However, rampant over-exploitation and consequent depletion affect aquifers across both terrains. Recent climate change issues pose a significant threat to groundwater development in Nigeria, impacting groundwater quality and availability. Other challenges include groundwater pollution from industrial, domestic, agricultural and urban activities and an acute lack of comprehensive management policies and regulatory frameworks. Sustainable development necessitates a robust approach involving broad hydrogeological investigations for proper aquifer mapping and characterization, continuous monitoring programs, promotion of managed extraction balanced with artificial recharge initiatives, strategic water distribution infrastructure, and robust policies for water resource protection and equitable utilization. With its sizeable groundwater reserves, Nigeria is positioned to derive substantial socio-economic benefits via an integrated strategy combining technical interventions with institutional strengthening for optimal, judicious, and widespread access to this precious resource across various sectors and communities.

   3. Chapter 14. Lead, Nickel, Arsenic, and Chromium Contamination in Nigerian Groundwater: Sources, Potential Impacts, and Removal Techniques

      Johnbosco C. Egbueri, Johnson C. Agbasi, Joshua O. Ighalo, Henry C. Uwajingba, Sani I. Abba

      Abstract

      Nigeria, like many other regions globally, faces challenges with groundwater contamination, particularly from toxic metal(loid)s such as lead (Pb), nickel (Ni), arsenic (As), and chromium (Cr). This chapter examined the sources, impacts, and removal techniques associated with Pb, Ni, As, and Cr contamination in Nigeria’s groundwater. It explored the geological, industrial, anthropogenic, and combined sources of these contaminants, their detrimental effects on human health and the environment, and various methods employed for their removal. It also explored the relationships between contamination sources and remediation techniques specific to Nigeria, emphasizing the need for tailored solutions. The novelty lies in providing insights into the unique challenges and opportunities for managing heavy metal contamination in Nigerian groundwater systems. These toxic elements in Nigerian groundwater pose significant health and ecological risks to the human and aquatic populations due to their bioaccumulation potential; and thus, demand effective mitigation strategies. Geological and environmental factors contribute to the metal(loid)s pollution in Nigeria, impacting both shallow and deep aquifers. Tracing and tracking these pollutants in Nigerian groundwater is very crucial for understanding the contamination sources and implementing remediation strategies effectively. The remediation of these heavy metal(loid)s in Nigeria employs physicochemical, biological, and hybrid methods. Several challenges were identified and highlighted in this chapter. Understanding these issues and challenges, policymakers, researchers, and stakeholders can develop informed strategies to safeguard water resources and protect public health in the country.