Water Resources and Integrated Management of the United Arab Emirates

By Abdulrahman S. Alsharhan and Zeinelabidin E. Rizk

This book provides an inventory of water resources, describes water challenges, and suggests methodologies and technologies for integrated water resources management in the UAE. It also summarizes efforts of water conservation and management, and modern approaches for improvement of water resources management and decision-making related to this valuable resource. The authors are specialized in geology and hydrogeology and have been teaching and conducting scientific research on water resources in the UAE for the last three decades. This book represents the main reference on water resources in the UAE for academia, researchers, professionals, students and the general public. 

• Language: English
• Publisher: Springer
• Release date: Mar 17, 2020
• ISBN: 9783030316846

Book preview

Part I

Introduction to Water Resources

This introductory part to water resources of the United Arab Emirates (UAE) summarizes the 28 chapters constituting this book. The introduction discusses the factors affecting water resources such as geomorphology and geology, climate and global warming and climate change.

The introduction also provides an inventory of conventional and non-conventional water resources in the UAE, highlights the challenges facing water resources and suggests water conservation strategies for water harvesting and management of agriculture water demand.

The review of water resources includes global figures about traditional and alternative water resources, water challenges and demographic drives. Water resources in the Middle East and North Africa (MENA) region, Arab world and the Gulf Cooperation Council (GCC) countries were also reviewed with discussion on available water resources, water demands and water challenges, with particular emphasis on the demographic drive.

The global conventional water resources include water in the oceans, continents, swamps, glaciers and ice sheets, lakes and reservoirs and rivers; while the non-conventional water resources are desalinated water and treated wastewater. In the present, the world consumes 8.4% of available water resources, and in 2025 the consumption is predicted to reach 12.2%. The annual renewable global water resources are 42,750 km³. The distribution of this water among continents varies in time and space. Asia and South America receive the largest share of earth’s water, while Europe and Australia receive the lowest share. The rapid increase in population lowered the per capita water share from 12,900 m³ in 1970 to 5926 m³ in 2014. The largest water shortage is in Africa, where the per capita water share dropped to one-third. During the same period, the per capita water share dropped to one-half in Asia and South America. The main global water challenges are the uneven distribution of water resources, water quality problems, escalating demands and climate change.

The MENA region is mostly arid and dry, receiving less than 1% of the earth’s water. The number of countries suffering from water shortage is expected to reach 18 countries in 2025, mostly are Arab countries. The annual per capita water share in most of the MENA countries is less than 200 m³, while the United Nations water poverty line is 1000 m³/person/year. About 15% of the world population receives over 50% of their water resources from neighboring countries, and many areas started witnessing disagreements around water shares.

The Arab countries are located in the heart of the MENA region, where rainfall is scarce, evaporation is very high and surface water resources are almost absent, except for a few rivers, originating in a more humid area outside the borders of Arab countries, and a limited number of low discharge springs. The per capita water share is steadily declining, and water challenges are over-exploitation of groundwater resources, lack of integrated water management, natural variability, absence of integrated management and development of shared water resources, water pollution and negative impacts of climate change on water resources.

The share of the Gulf countries of the total water resources in the Arab region is less than 5%. The water demands always surpass available conventional resources, which puts these countries, particularly Saudi Arabia and UAE in the lead of water desalination in the world. Both countries produce 30% of the global production of desalinated water, and the Gulf region produces more than 50% of the world’s production. The main water challenges include reduction of non-revenue water, industrial water and wastewater management, water use and policy reform in the agricultural sector.

© Springer Nature Switzerland AG 2020

A. S. Alsharhan, Z. E. RizkWater Resources and Integrated Management of the United Arab EmiratesWorld Water Resources3https://doi.org/10.1007/978-3-030-31684-6_1

1. Introduction to Water Resources of the United Arab Emirates

Abdulrahman S. Alsharhan¹  and Zeinelabidin E. Rizk²

(1)

Middle East Geological and Environmental Establishment, Dubai, United Arab Emirates

(2)

University of Science and Technology of Fujairah, Fujairah, United Arab Emirates

Abstract

This chapter summarizes the book ten parts. Part one provides an overview of global water resources. Part two discusses the impact geomorphology on surface water resources and influence of geology on groundwater. Part three describes the main features of the UAE climate and illustrates the impacts of global warming and climate change on water resources. Part four presents the results of investigating seasonal floods, springs, aflaj systems and groundwater resources. Part five discusses desalinated water and treated wastewater. Part six identifies the challenges facing water resources and investigates groundwater pollution. Part seven deals with water conservation, water harvesting techniques and the positive impacts of application of modern irrigation technologies on water resources conservation. Part eight describes the use of remote sensing, GIS, isotope hydrology and modeling techniques in water resources investigations. Part nine analyzes water governance and provides recommendations for improving integrated water resources management. Part ten summarizes water resources and water demands, and efforts of maximizing resources and managing demands. The volume ends by the conclusions, covering all the themes of this book.

The scarcity of basic references on water resources in the Arab countries in general, and the Arabian Gulf region in particular, was the motivation to prepare this book. The United Arab Emirates (UAE) is no exception as a country about which there is no single reference book on water resources. In the meantime, there is an urgent need for a comprehensive text book that can provide an inventory of available water resources, diagnose the main challenges facing conventional and nonconventional water sources , and suggest viable methodologies and technologies for improvement of the current water-resources management in the UAE.

The authors participated in writing the first book on the hydrogeology of the Arabian Gulf and adjoining areas, published by Elsevier in 2001. The authors specialize in geology and hydrogeology and have been teaching and conducting scientific research on water resources of the UAE for more than two decades. Therefore, it was important to compile the results of their research efforts, along with the results of other relevant studies published by researchers, released by relevant authorities in the UAE and included in publications of regional and international organizations, in one reference book.

This book constitutes a main reference on water resources in the UAE for university students, researchers and the general public. The scientific research on which this book is founded was initially written in English and published in regional and international journals, which limits the access to information to the English-speaking community. In 2008, the authors wrote an Arabic version of a reference book on water resources in the UAE, to give the Arabic-speaking readers, researchers and students access to this vital information. However, the huge volume of information added since 2008 until now necessitated preparation of this book to serve as a basic, comprehensive reference on almost all aspects of water resources in the UAE.

The natural water resources in the UAE, which have historically been limited, are facing serious challenges due to the ambient natural conditions represented by the scarcity of rain, high evaporation rates , rapid population growth, expansion of cultivated lands, exceptional urban development and increased industrial activities.

These conditions require availability of information on conventional water resources such as flash floods , natural springs , aflaj systems and groundwater, and non-conventional water resources including desalinated water and treated wastewater , for government agencies, private sectors and foreign investors as well.

To address the main issues regarding water resources in the UAE, the authors has sought to provide the reader of this book with comprehensive and clear answers for several basic questions about water resources in the UAE, their sources, the main challenges facing water resources and suggested solutions.

This book contains 28 chapters and is divided into ten parts as follows:

Part I (Chaps. 1 and 2) provides an introductory statement for each chapter and an overview on water resources ranging from global to local perspectives .

Part II (Chap. 3) illustrates how geomorphology controls the volume and direction of seasonal floods , while geology determines the nature, setting and geologic structures of the aquifers and their influences on the presence, movement recharge and quality of groundwater.

Part III (Chaps. 4 and 5) summarizes the main features of the UAE climate and illustrates the impacts of global warming and climate change on water resources; it also presents the finding of investigating the climatic water balance and the hydraulic properties of sand dunes .

Part IV (Chaps. 6, 7, 8, 9, 10, 11, 12, and 13) presents the results of investigating surface water resources: seasonal floods, springs and aflaj systems and groundwater resources ; and limestone aquifers , ophiolite aquifer , gravel aquifers , sand aquifer and sand-and-gravel aquifer system .

Part V (Chaps. 14 and 15) provides results of studies on the nonconventional water resources: desalinated water and treated wastewater. The results of investigating evolution, the prospects and environmental impacts of production and usage of nonconventional water resources are presented.

Part VI (Chaps. 16, 17, and 18) identifies the challenges facing water resources: drinking water sources , standards and quality and results of investigating groundwater pollution of various aquifers.

Part VII (Chaps. 19, 20, and 21) deals with water conservation , conventional and modern water harvesting techniques and the positive impacts of application of modern irrigation technologies on water-resource conservation.

Part VIII (Chaps. 22, 23, 24, and 25) describes the use of remote sensing , GIS , isotope hydrology and modeling techniques in water-resources investigations.

Part IX (Chap. 26) analyzes water governance and provides recommendations for increasing coordination and improvement of integrated water-resource management .

Part X (Chaps. 27 and 28) summarizes water resources and water demands and efforts to maximize resources and manage demands. The volume ends with conclusions that cover all the themes of this book.

Chapter 1 summarizes the 28 chapters constituting this book. The introduction discusses the factors affecting water resources such as geomorphology and geology, climate and global warming and climate change . It also provides an inventory of conventional and nonconventional water resources, highlights the challenges facing water resources and suggests water-conservation strategies, such as water-harvesting techniques and the management of agricultural water demand.

Chapter 2 provides an overview of water resources in the world, Middle East and North Africa (MENA) region, Arab world and Gulf Cooperation Council (GCC) countries. Each of the above sections includes an inventory of available conventional (floods, rivers, springs, aflaj and groundwater) and nonconventional (desalinated water and treated wastewater) water resources. The chapter also discusses water demands , water challenges and the demographic trends.

An overview on global water resources including the main conventional water body stored in oceans , covering the Antarctic, Arctic and glaciers of high-mountain peaks and water stored in great lakes , running in great rivers and or stored at variable depths in the ground. The water available for direct human use is mostly groundwater (96.80%), while lakes (3.18%) and rivers (0.02%) carry minor amounts. Nonconventional water resources are desalinated water and treated wastewater. The rapid increase of population has reduced the global per capita water share from 12,900 m³ in 1970 to 5926 m³ in 2014. The main global water challenges are the uneven distribution of water resources , water-quality problems, escalating demand and negative impacts of global warming and climate change on water resources.

The MENA region is about 8% of the world’s area, inhabited by 5% of the world’s population, but has less than 1% of the Earth’s water. The number of countries suffering from water shortage is expected to reach 18 countries in 2025, most of them Arab. The annual per-capita water share in Yemen, Jordan, Bahrain, Libya, and most of the Gulf Cooperation Council (GCC) countries, including the UAE, is less than 200 m³. About 15% of the world population receives over 50% of their water resources from neighboring countries, and many areas have started witnessing disagreements around water shares.

The annual renewable, conventional water resources in the Arab region are estimated at 338 Bm³: 296 Bm³ surface water; 42 Bm³ groundwater recharge ; and 15,000 Bm³ of nonrenewable water resources. In 2035, the per capita water share in the Arab region is predicted to reach 464 m³. The water challenges in the Arab region are over-exploitation of groundwater resources , lack of integrated water management, natural variability, lack of cooperation and coordination in development and management of shared water resources , water pollution and negative impacts of global warming and climate change on water resources.

The share of the GCC countries of the total water resources in the Arab region is 4.6%. The total water resources in the Arabian Gulf countries between 1988 and 1997 reached 10.31 Bm³, including 8.00 Bm³ of conventional and 2.31 Bm³ of nonconventional resources, while water demand is expected to reach about 32.23 Bm³ by 2025. The per capita share of available water resources in the GCC countries is less than 250 m³/year, while the per capita water consumption in the region is 1035 m³/year. The main water challenges include reduction of non-revenue water , management of industrial water and wastewater, increasing water usage and policy reform in agricultural sector.

Chapter 3 deals with the geomorphology and geology and their influence on surface and groundwater resources . Geomorphic features control surface water and determine the directions of flood flows, while the geologic setting dictates the distribution aquifers and confining units . Geologic structures may either block the passage of water or create preferential, natural passways acting as conduits accelerating water movement in many areas.

The major geomorphic features in the UAE include: the eastern mountain ranges , gravel plains surrounding the mountains on the east and west, sand dunes , sabkhas , drainage basins and coastal areas . The low porosity and hydraulic conductivity of the rock-forming mountains coverts most of the rain falling on these mountains into surface runoff . The runoff water moves rapidly towards the gravel plains in the east and west, turning them into the most important, renewable, freshwater aquifers in the country. Sand dunes cover most of ​​ the Western Region stretching between the western gravel plains in the east and the sabkha deposits along the Arabian Gulf in the west. The coastal areas include tidal flats and coastal sabkhas . The inland sabkhas occupy topographic depressions between sand dunes and act as areas of groundwater discharge .

Despite the absence of surface-water resources such as rivers and lakes , dry drainage basins interrupt the continuity of rock outcrops and gravel plains through a network of dry drainage basins which may carry water during the rainy seasons. The drainage basins in mountains are represented by dense trellis and rectangular patterns because of the differences in lithology and geologic structure, while the drainage basins in gravel plains are characterized by dendritic and braided patterns because of the homogeneity of the plains’ sediments.

This chapter also describes the geologic conditions, stratigraphic sequence and the hydrogeologic characteristics of various formations in terms of their relationship to water. Most of the surface area of the UAE is occupied by two main depositional basins; Ras Al Khaimah basin in the north and east and Rub’ al Khali basin in the south and west. The stratigraphic sequence in the UAE ranges in age from the Devonian Period of Paleozoic Era to the Quaternary Period. The Quaternary sediments cover most of the Western Region in the UAE. The rock sequence in Ru’us Al Jibal Mountains extends between the Permian and Early Triassic ages and represents the main aquifer in Wadi Al Bih basin at Ras Al Khaimah Emirate. The Dammam Formation of the Eocene age represents the main aquifer in the vicinity of ​​Jabal Hafit in the Al Ain area. The gravel deposits and sand dunes of the Quaternary age represent the most important aquifer in the UAE.

The chapter also discusses the surface and subsurface geologic structures affecting, directly or indirectly, surface water and groundwater resources . These structures include Ru’us Al Jibal, the Dibba zone , the Wadi Ham line , the Hatta zone , Jibal Al Fayah and Hafit in the Eastern Region, as well as subsurface structures in the Western Region of the UAE.

Chapter 4 discusses the climatic conditions in the UAE, which is one of the key determinants of the hydrogeologic conditions in the country. Coincidentally, rainfall scarcity due to high natural evaporation is the main cause of the prevailing drought and lack of surface water resources, such as rivers and lakes . The scarcity of rain leads to minimal recharge of aquifers and groundwater depletion . The average daily sunshine in the UAE is 10 h, and the air temperature can reach 50 °C during the summer. The relative humidity varies between 20% in the Liwa oasis and 90% in coastal areas .

The two principal wind systems affecting the climate are the winter cyclonic depressions, which descend the Arabian Gulf from the north and northwest and give rise to the cold northwesterly Shamal (Arabic word meaning north) airflow; and the summer monsoonal low develops over the Rub’ al Khali (Arabic term meaning empty quarter) desert. The Shamal winds affect the western coastal cities of Abu Dhabi, Dubai, Sharjah , Ajman , Umm Al Quwain and Ras Al Khaimah, while the summer monsoon affects the Eastern Region’s cities of Fujairah , Khor Fakkan, Dibba and Kalba.

The annual evaporation rates are 20–30 times higher than the mean annual rainfall , but the use of monthly and daily records of rainfall is more realistic in evaluating groundwater recharge . The analysis of climatological data for the period 1976–2015 indicates that February is the rainiest month, while July is the driest month and has the highest evaporation rate.

This chapter also discusses global warming and climate change and their negative impacts on water resources. These impacts are induced by variation of temperature and rainfall and cause decline of aquifer recharge , shortage of irrigation water, aquifers’ depletion and increasing groundwater and soil salinities.

Chapter 5 studies the climatic water balance and analyzes the relationship between rainfall and potential evapotranspiration (PET) in the Al Ain area. The study results distinguish water-surplus areas from water-deficit ones. In water-surplus areas, part of rainwater can contribute to groundwater recharge. In contrast, water-deficit areas suffer from severe drought because the monthly PET rates greatly exceed monthly rainfall. Results of grain-size analysis and infiltration capacity (Ic) measurements were used for determining the hydraulic properties of gravel plains and sand dunes around Al Ain City.

The study was a trial to understand the mechanisms of groundwater recharge in the sand dunes and gravel plains, which cover about 80% of the surface area of the UAE. The study indicated that the percentage of runoff from rainfall is 18% in the eastern mountain ranges and 3% in the Jabal Hafit area. The results of this study can help in identifying areas for aquifer-storage recovery (ASR) projects, which has already started in more than one emirate. In this regard, the gravel plains and sand dunes are the most favorable sites for artificial groundwater recharge , especially where these aquifers are severely depleted due to over-exploitation of groundwater.

Chapter 6 provides detailed discussion of seasonal floods in the Eastern Region of the UAE and analysis of rainfall-runoff relationship , flood volumes and rainfall amounts that may lead to surface runoff . It also deals with classification of dry drainage basins in the eastern UAE and their flood potential . It investigates flash floods , flood hazards and the flood potential of various drainage basins.

The chapter discusses the role of groundwater-recharge dams in harvesting flood water , which used to drain into the Gulf of Oman along the east coast, the Arabian Gulf in the northwest and desert plains in the west and southwest. Flood water used to cut off roads and destroy farms and houses, but now, a good part of this water is harvested by a large number of recharge dams . It is estimated that 120 million m³ of flood water are annually harvested by recharge dams built in main wadis. The drainage basins in the UAE need detailed investigation to help set priorities of site selection for future recharge-dam projects.

Chapter 7 includes discussion of the geology, hydrogeology and hydrochemistry of the few permanent springs in the UAE. It also provides evaluation of the suitability of spring water for irrigation, recreation and therapeutic uses. These springs are located along definite structural elements, within various drainage basins, at variable topographic elevations and drain different rock types, which affect the springs’ discharge , water chemistry and water quality .

Based on discharge rates , Bu Sukhnah spring ranked second and Khatt springs fourth in volume. The discharge of Khatt springs is directly related to rainfall, while the discharge rates of the Bu Sukhnah springs is not directly related to local rainfall . High spring-water temperatures (39 °C in Khatt north, 39.5 °C in Bu Sukhanah and 41 °C in Khatt south) are related to deep groundwater circulation or radioactive decay at depth, especially in the case of Bu Sukhnah spring.

Chapter 8 investigates the geologic setting, hydrogeology, water chemistry and water quality of aflaj systems in the UAE, which provide a limited amount of renewable water. Aflaj systems are a part of the cultural heritage in the UAE, and their water has been used for all purposes in the past, but recently, aflaj water is mainly used for irrigation in the northern and eastern parts of the country.

Despite the small volume of annual aflaj discharge , which varies between nine and 31 Mm³, representing 3–10% of the total water used in the UAE, aflaj water is renewable and their discharge can be increased by maintaining their channels and tunnel systems. This chapter also discusses aflaj origin, history, design, management, water quality and suitability for irrigation .

Chapter 9 discusses the results of investigation on the limestone aquifers in the Wadi Al Bih basin, Jabal Hafit and the Western Region of the UAE. The Wadi Al Bih limestone aquifer is the main source of water in Ras Al Khaimah City. For this reason, the hydrogeology , hydrogeochemistry , isotope hydrology and water quality of the aquifer were studied in detail over a long period of time.

The geology and hydrogeology, hydrogeochemistry and isotope hydrology of the Dammam limestone aquifer in the Jabal Hafit area were also investigated. The aquifer there produces about 7.7 Mm³/year of hot, salty water of high therapeutic value . The area has been developed as a touristic site and for recreation. In the Western Region of the Abu Dhabi Emirate, the limestone aquifers of Dammam, Umm Er Radhuma and Simsima, ranging in age from Upper Cretaceous to Eocene , are highly saline with salinities varying between 70,000 and 230,000 mg/L. Water from these aquifers is injected into oil fields to maintain reservoir pressure.

Chapter 10 deals with the ophiolitic aquifer, which is a low productivity aquifer, except in areas where the intensity of joints, folds, faults and fractures increase the secondary porosity (θ), hydraulic conductivity (K) and productivity of the aquifer. The aquifer’s average transmissivity (T) and specific yield (Sy) are 776 m²/day and 0.24, respectively.

The chapter also discusses the linear features and their geologic and hydrogeologic influence on groundwater levels , chemistry, quality and use. The groundwater quality in the ophiolite aquifer is good because its matrix is hardly soluble in water. But, the water salinity increases with increasing depth due to lower density of fractures , smaller size of cracks and the slow velocity of groundwater flow . Three structural zones affect the ophiolite aquifer : the Dibba zone , Wadi Ham line and Hatta zone . These zones do not only affect groundwater resources but also control the distribution of urban centers, farms, water-well fields and sabkha deposits.

Chapter 11 discusses the gravel aquifers, which store the largest reserve of fresh , renewable groundwater in the country. These plains bound the eastern mountain ranges on the east and west and are distinguished into two aquifer types: the eastern gravel aquifer and the western gravel aquifer. The eastern gravel aquifer extends from Dibba in the north to Kalba in the south.

Groundwater water in this aquifer is the main source of water used for agricultural, industrial and domestic purposes. Irrigation consumes about 90% of water resources in the eastern coastal region because of the intensity of farming and agricultural activities. However, excessive groundwater pumping over the past four decades has dramatically lowered groundwater levels, degraded water quality and increased salt-water intrusion in many areas.

The western gravel aquifer extends between Ras Al Khaimah in the north and Al Ain area in the south. The aquifer covers the area between rock outcrops of the eastern mountain ranges and sand-dune fields in the west. The aquifer also extends under the sand dunes, as buried alluvial channels , representing aquifers of high water quality and productivity.

Chapter 12 offers a detailed study of the Quaternary sand-dune aquifer in Liwa and Bu Hasa areas. The study provides in-depth discussion of hydrogeology , groundwater chemistry and isotope hydrology of the aquifer. Two fresh -water mounds belonging to the Liwa Quaternary sand aquifer represent relics of an old, large aquifer that occupied the northwestern part of the Liwa area during Pleistocene–Holocene pluvial periods. Another, but smaller, freshwater mound exists between Habshan Station and the Bu Hasa oilfield. The striking similarity of hydraulic properties , hydrogeochemistry and natural isotopes of the groundwater at Liwa and Bu Hasa permitted dealing with the aquifers in both areas as a single aquifer named by the authors the Liwa Quaternary sand aquifer.

The depth to groundwater varies between a few meters and 50 m at Liwa oasis , and from 24 to 52 m at Bu Hasa oilfield. The aquifer’s saturated thickness ranges from 75 m at the Shah oilfield to 175 m at the Bu Hasa oilfield; hydraulic conductivity (K) is 2.3–8.5 m/day, transmissivity (T) varies between 200 and 650 m²/day; and specific yield (Sy) is 0.1–0.3. Although sand dunes cover 74% of the total area of the UAE, the Liwa Quaternary sand aquifer is the least studied in the country and needs additional detailed investigation.

Chapter 13 covers discussion of the sand and gravel sediments as a single aquifer system because most of the hydrogeological studies confirmed that the sand and gravel sediments experience hydraulic continuity, and in many areas it is difficult to distinguish the gravel from the sand aquifers. Therefore, this chapter summarizes the findings regarding the geologic setting, hydrogeologic characteristics , groundwater chemistry and isotope hydrology of the sand gravel aquifer system .

The depths to groundwater, hydraulic heads and groundwater chemistry suggest the presence of three groundwater flow systems . The presence of these systems affect water chemistry and quality in the aquifer. Local groundwater flow systems contain water of brief residence times, low salinity and good quality. Intermediate groundwater flow systems discharge into inland sabkhas , where water is generally brackish and has a moderate residence time . Regional groundwater flow systems discharge into coastal sabkhas ; water in these systems is highly saline, has a long residence time and discharges near the shoreline of the Arabian Gulf in the west.

The measurements of stable and radioactive isotopes indicate that the age of groundwater in the sand and gravel aquifer system increases from east towards west, in the direction of groundwater flow . Isotopes also confirmed the hydraulic connection between the gravel aquifer in the east and the sand aquifer in the west, without the possibility of defining a clear boundary between the two units in many areas.

Chapter 14 discusses water desalination in the UAE in terms of the technologies used and the evolution of the industry itself. The chapter focuses on the increasing role of desalinated water in bridging the gap between limited conventional water resources and growing demand for water. The chapter also investigates the advantages and disadvantages of the desalination industry and its impacts on marine and terrestrial environments . In addition, the chapter discusses approaches for alleviating the negative impacts of the desalination industry and proposes an innovative approach for brine recycling and achieving zero brine discharge .

Chapter 15 deals with treated wastewater as an additional, renewable supply of water and its major role in easing pressure on conventional water resources in the future. The annual volume of treated wastewater has greatly exceeded the annual amount of groundwater recharge . The role of treated wastewater is likely to increase in the future because of continuous urban expansion and extension of drainage networks to serve ongoing urban development.

There are 78 wastewater treatment plants , producing 711 Mm³ in 2015. Two-thirds of treated wastewater is used for irrigation and landscaping, and a third is discharged either into the sea or the desert. This chapter also discusses the advantages and limitations of using treated wastewater and addresses the evolution wastewater reuse in the UAE and presents two case studies of wastewater treatment in Abu Dhabi and Ras Al Khaimah emirates.

Chapter 16 addresses the problems facing conventional water resources , including seasonal floods , permanent springs , aflaj systems and groundwater stored in various aquifer systems . The chapter also deals of problems facing nonconventional water resources, including desalinated water and treated sewage water. The problems facing surface-water sources are pollution from surface sources, inadequate quality for domestic uses, scarcity and absence of recent recharge. The groundwater resources receive limited recharge from rain in the northern and eastern parts of the country and are generally suffering from scarcity, water logging and unsuitability for irrigation and pollution.

The chapter discusses the depletion of aquifers throughout the country, increasing groundwater salinity , water hardness , deterioration of groundwater quality , dryness of a large number of wells and the salt-water intrusion problem. The chapter also addresses aquifers’ pollution caused by natural sources and human-related activities, particularly agriculture and oil industries.

The thermal desalination plants suffer from scale formation and precipitation , while the reverse-osmosis plants’ membrane face fouling and corrosion . Discharge of reject brines into coastal areas leads to negative physical, chemical and biological impacts on marine environment , while uncontrolled disposal of reject brines from inland desalination plants , leads to serious pollution problem to fresh groundwater resources.

The problems facing reuse of treated wastewater are mainly psychological, such as fear of diseases, unrest and belief that this water is unsafe, irrespective of the level of treatment. However, there is a direct relation between certain diseases and the use of treated sewage water for irrigation. Conventional wastewater treatment techniques do not completely remove harmful pathogenic Bactria and viruses and leads to accumulation of heavy metals .

Chapter 17 offers an integrated study of water used for drinking and domestic purposes in the UAE. About 400 samples from various different sources, including bottled water , desalinated water and groundwater used for drinking and domestic purposes were analyzed in the context of this study. The study compared the concentrations of major, minor and trace chemical constituents in studied water with the national and international recommended and maximum permissible limits for drinking water . Results of this study revealed a wide variation in concentrations of major, minor and trace inorganic chemicals in drinking and domestic water. Some brands of bottled water are almost free of trace ions and minor constituents, but natural groundwater used might have concentrations higher than the WHO recommended limits for drinking water.

The main cause for this variation is related to the different water sources and the large number of companies working in production and distribution of drinking and domestic water. The current controls on domestic water quality in some areas, namely conformance of pH and electrical conductivity measurements with prescribed ranges of values, are inadequate. These two parameters are not enough to judge if water is suitable for drinking or not, and some consumers may receive domestic water of uncertain quality.

Chapter 18 describes case studies of groundwater pollution of various aquifer systems in the UAE. Recent investigation of Wadi Al Bih limestone aquifer in Ras Al Khaimah Emirate revealed that the aquifer is highly sensitive to urban and agricultural development, and several wells, in the Wadi Al Bih and Al Burayrat areas, were reported to contain Coliform bacteria .

Remote sensing (RS) and GIS studies showed that intensive agriculture, human activities and dissolution of carbonate rocks in the Al Ain area are contributing to the degradation of groundwater quality in the western gravel aquifer in the Eastern Region of the UAE. Major ions chemistry and nitrate isotopes identified the sources of nitrate pollution of the Liwa Quaternary sand aquifer as animal waste (10%), soil nitrogen (25%) and fertilizers (65%).

The study of the roles of the prevailing climate, geology and hydrogeology in groundwater pollution of the Quaternary sand and gravel aquifer in Ajman area identified point and nonpoint sources of pollution, related to natural conditions and human activities. Based on the results of field studies and chemical analyses of collected groundwater samples , recommendations were made for pollution control.

Chapter 19 discusses water conservation through the application of integrated water- resources management (IWRM) approach, through community practices and technological solutions. Each emirate has at least a law or an Amiri Decree regulating the drilling of water wells and groundwater extraction and protection. In addition, the government has built more than 130 dams capable of storing 120 m³, as well as planning to build 68 additional dams in the future. Recharge dams conserve flood water , enhance groundwater recharge and protect homes and farms against the danger of flash floods .

The chapter also identifies water use in the UAE and provided suggestions for reducing water losses . The Abu Dhabi Food Control Agency (ADFCA) has provided a number of initiatives for reducing water wastage in the agricultural sector, including reduction of water consumption in farms, use of treated wastewater for irrigation, promoting good agricultural practices, phasing out Rhodes cultivation, improving irrigation networks, the application of smart irrigation systems , improvement of soils and expansion of greenhouse agriculture . The chapter also describes efforts for raising public awareness of water issues and mechanisms for dealing with water problems on individual and society