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1. 52o 53o 54o 55o 56o Iraq Ras Al Khaimah N Iran Kuwait Arabian Diba Gulf of Oman Gulf Qatar Dubai UAE Saudi Arabia Red Sea 25o Oman Arabian Gulf Kalba Yemen Arabian Sea AFRICA Abu Dhabi Al Ain 24o OMAN UNITED ARAB EMIRATES SAUDI 23o 50 km ARABIA Water Resources in the UAE

2. Water Resources - United Arab Emirates Water Resources in the United Arab Emirates • Summary • Objectives • Geomorphology • Mountains • Gravel Planes • Sand Dunes • Coastal Areas • Drainage Basins • Geology • Geologic Setting • Structural Conditions

3. Water Resources - United Arab Emirates • Climatic Conditions • Solar Radiation • Air Temperature • Relative Humidity • Evaporation • Evapotranspiration • Winds • Precipitation • Conventional Water Resources • Seasonal Floods • Springs • Falajes • Groundwater • Limestone Aquifers • Ophiolite Aquifers

4. Water Resources - United Arab Emirates • Gravel Aquifers • Sand Dune Aquifers • Non-Conventional Water Resources • Desalination Water • Treated Sewage Water • Water Problems • Depletion • Salt-Water Intrusion • Water-Quality Problems • Suggested Solutions • Modern Irrigation Techniques • Human Development • Modern Management Tools

5. Water Resources - United Arab Emirates NON-VCONVENTIONAL WATER RESOURCES Desalination Water Two main types of desalination processes are now available commercially: distillation processes and membrane processes. The most important distillation methods are multi-stage flash distillation and multi-effect distillation. Both involve the evaporation of saline feed water and its condensation back into fresh water, leaving dissolved substances in the waste brine. In multi-stage flash, a stream of brine flows through the bottom of up to 25 stages or chambers. The pressure in each chamber is maintained at a lower level than the saturation vapor pressure of the water and a proportion of it flashes into steam and is then condensed.

6. Water Resources - United Arab Emirates In multi-effect distillation, evaporation takes place as a thin film of feed over a heat-transfer surface. Water desalination in UAE started since 1973 in Abu Dhabi at an annual production rate of 7.0 million m3, reaching 395 million m3 in 1997. Since 1974, over thirty desalination plants have been built in UAE. Most of the plants are on the coast or on islands, although small number occurs inland, such as Al Burayrat (Ras Al Khaimah) and As Surrah (Umm Al Quwein), where brackish groundwater is desalinated. The number of desalination plants in UAE increased from one station at Abu Dhabi during 1976 to 65 stations in the 1995, with each Emirates having at least one desalination plant (Table 6 and 7; Figure 25).

7. Water Resources - United Arab Emirates Table 6. Water resources in UAE and other Gulf countries.

8. Water Resources - United Arab Emirates Table 7. Number of desalination plants in UAE.

9. Multi-Stage Flash Multi-Effect Boiling Vapor Compression Reverse Osmosis Number of Plants Water Resources - United Arab Emirates Figure 25. Number of desalination plants in UAE.

10. Water Resources - United Arab Emirates The daily production of desalinated water in the Abu Dhabi Emirate, for example, jumped from 12.5 thousand m3 in 1969 to 590 thousand m3 in 1989. This wide increase in production of desalinated water is also listed and illustrated in Table 8 and Figure 26. The desalinated water industry represents one of most important water source in UAE in the present time and it needs to expand in order to meet the increasing demand for water. It is also important to start local industry that can provide chemicals and spare parts needed to water desalination plants operating in UAE and possibly other Gulf countries. The support of scientific research towards the use of solar energy for water desalination is also needed.

11. Water Resources - United Arab Emirates Table 8. Quantities of desalinated water produced in UAE.

12. Water Resources - United Arab Emirates Table 9. Quantities water produced in UAE.

13. 1995 1996 1997 386 million m3 580 million m3 694 million m3 Water Resources - United Arab Emirates Figure 26 . Quantities of desalinated water produced in UAE.

14. Water Resources - United Arab Emirates The best advances made in desalination industry is the energy recovery, where the heated brines can be recycled again through the system to make use of their heat. This has lowered the production cost of desalinated water (Figure 27). Treated Waste Water Every drop of water must be carefully used in an economically feasible manner so that no higher quality water should be used for a purpose that can tolerate a lower quality. As a substitute for freshwater in agriculture and industry, treated wastewater has an important role to play in water resources management in UAE.

15. Cost of One Cubic Meter (UAE Dhs) Year Water Resources - United Arab Emirates Figure 27. Price of produced desalinated water in UAE.

16. Water Resources - United Arab Emirates The estimated treated sewerage water annually in UAE is 150 Million m3, and used in irrigation of Public Parks and beautifulizing streets and roundabouts of major cities, The discharge of sewage treated water has exceeded 175 million m3 in the year 2000 (Figure 28). It is worth mentioning that the sewerage water treated primarily, secondary and tertiary could be used in the irrigation especially after treatments it becomes void of poisons and heavy minerals. The Sewage water could be used for industrial usage, to recharge the aquifer and could be used as additional source of drinking water only after assurance of being good quality for such usage.

17. Volume (MCM) Year Water Resources - United Arab Emirates Figure 28. Volume of treated sewage water produced in the United Arab Emirates.

18. Water Resources - United Arab Emirates In UAE, there are four sewage treatment plants in Abu Dhabi, Dubai, Al Ain, and Al Sharjah. The first sewage treatment plant was constructed in Abu Dhabi during 1973 at a daily capacity of 4,000 m3. The capacity of the plant reached 120,000 m3/day in 1994. The Al Aweir plant in Dubai has a daily capacity of 110,000 m3. The plants provide primary, secondary (biological treatment), and tertiary (advanced) treatments, which improve the quality of produced water and makes it suitable for reuse in irrigation. Table 10 shows the treated-sewage water compared with the water quality criteria for irrigation. The table shows that the produced water is fit for reuse in irrigation, especially it does not contain heavy metals.

19. Water Resources - United Arab Emirates Table 10. Characteristics of treated sewage water in UAE.

20. Water Resources - United Arab Emirates Chlorinating the treated sewage water for disinfections during the tertiary treatment kills germs and microorganisms that are health hazards. The economic feasibility for the treatment of sewage water and its usage depend on many factors, such as the cost of treatment and the degree of required treatment in comparison to the cost of producing alternative water source for the same usage. The cost of producing one m3 of desalinated water is 5 UAE Dirhams, whereas the cost of producing one m3 of treated sewage water is 2 Dirhams. A question still remains about the possible use of treated sewage water in irrigation and chemical and biological pollution to the plants, soils and groundwater, in addition to the possible health hazards associated with the use of sewage treated water in irrigation.

21. Water Resources - United Arab Emirates It is possible to avoid such consequences by safe treatment, which insures getting red of pollution and purifying the system for ideal water treatment to be used for plant irrigation. It is a must to make periodical analysis and field study to follow the safe use of treated sewage water for irrigation and to educate the community in the same field to avoid adverse effect of working and health environment related to it. WATER-RELATED PROBLEMS Depletion Comparison between the annual groundwater recharge and groundwater abstraction rate, which are used mainly to fulfill the agricultural sector demands, indicates that most of the groundwater resources in UAE are over-drafted and are depleting.

22. Water Resources - United Arab Emirates In other words, water abstracted is being taken from groundwater storage, with no significant recharge for the amounts withdrawn. The estimated annual recharge for groundwater in UAE is 120 million m3, while the groundwater abstraction, mainly by the agricultural sector, is 880 million m3 per year. This unbalanced situation has resulted in a continuous decline in groundwater levels and quality deterioration in most of the well fields due to seawater and upconing of highly-saline formation waters. Salt-Water Intrusion The possible sources of salt-water intrusion are: salt-water intrusion from the sea in coastal regions, lateral movement of saline water from a nearby sabkha-dominated areas, or upconing of saline water from lower stratigraphic units into shallow fresh water aquifers.

23. Water Resources - United Arab Emirates Ajman Umm Al Quwain Ras Al Khaimah Sharjah Fujairah TDS (mg/l) Year Figure 29. Increase of groundwater salinity in observation wells in wellfields the UAE.

24. Water Resources - United Arab Emirates The Cl/(CO3+HCO3) ratio is used to evaluate salt-water intrusion. The chloride ion (Cl-) is a dominant anion in salt water and normally occurs in small  amounts in groundwater. The bicarbonate ion (HCO3-) is the most abundant anion in groundwater. Figure 30 shows that groundwater in most of the country is suffering from serious salt-water intrusion problems, except for the central part of the ophiolite aquifer. Figure 30 indicates that salt-water intrusion into relatively fresh ground water of the Quaternary aquifer in the Al Ain area is now taking place in the southwestern part of the study area as a result of excessive groundwater pumping for different purposes. Salt-water intrusion in this area is also indicated by the dominance of MgCl2 and NaCl salts.

25. 52o 53o 54o 55o 56o Ras Al Khaimah N Diba Gulf of Oman Arabian Gulf Dubai 25o Kalba Abu Dhabi Al Ain 24o OMAN UNITED ARAB EMIRATES SAUDI 23o 50 km ARABIA Water Resources - United Arab Emirates Figure 30. Areas suffering from salt-water intrusion in the UAE.

26. Water Resources - United Arab Emirates The Na/Cl ratio in seawater is less than unity (0.85), while groundwater has Na/Cl ratios greater than unity. Therefore, it is used to indicate areas suffering from salt-water intrusion. Figure 30 shows salt-water intrusions problems in Ras Al Khaimah, Al Dhaid, Diba, Kalba, Dubai Jabal Al Dhanah, Madinat Zayed, Liwa and Al Ain. Water Quality Problems Oil Industry Between 1964 and 1985, the groundwater salinity increased in the Bu Hasa camp area from 3,500 mg/l to 5,500 mg/l. The iso-salinity contour map constructed with the field data collected by the author in April 1996 indicates that the salinity of groundwater in the southeastern part of the Bu Hasa area has tripled during the period 1985-1996, mainly because of the disposal of oil-field brines in unlined pits in this area.

27. Water Resources - United Arab Emirates Evaluation of possible contamination of the fresh water Quaternary Liwa aquifer in the Bu Hasa oil field by highly saline, metal and oil-bearing effluent generated in association with produced oil was assessed. The factors that may control contamination such as stratigraphic setting, geologic structure, groundwater-flow direction and water chemistry were taken into consideration and evaluated. Results of the study shows that the examined groundwater from the Quaternary Liwa aquifer is free of hydrocarbon pollution. In contrast, the water disposed in the Miocene clastic aquifer is loaded with high concentrations of aliphatic and aromatic compounds. If this water could reach the Quaternary aquifer, it can cause a serious contamination problem, especially for the domestic water-well field.

28. Water Resources - United Arab Emirates The plot of 2H (‰) versus 18O (‰) for water samples from the Liwa and Bu Hasa areas suggests that the oil-field water and water of the Quaternary Liwa aquifer are different, indicating the effective sealing of the Miocene evaporites in the Bu Hasa area. This seal prevents upward movement of wastewater from the Miocene clastic sediments into the Quaternary Liwa aquifer. In contrast, groundwater in the Bu Hasa area seems to have stable isotopic composition identical to that of groundwater in the Liwa area, indicating a common source. Based on the geologic, hydrogeologic, hydrochemical and stable isotope analyses, there is no reason to believe that the disposal of waste water in the Miocene clastic aquifer in the Bu Hasa area can lead to the upward movement of this water contaminating the shallow Quaternary aquifer.

29. Water Resources - United Arab Emirates In contrast, the disposal of brines in unlined pits is the practice that has a definite adverse effect on the Quaternary Liwa aquifer in the Bu Hasa area. Agriculture According to Freeze and Cherry (1979), nitrate (NO3-) is the most common identified contaminant in water. The WHO (1971) recommended limits for nitrate in drinking water are 10 mg/l as nitrate nitrogen and 45 mg/l as nitrate (NO3-). Centers of high NO3- are encountered in Wadi Al Bih, south of Dubai, Al Ain, Al Khaznah, Madinat Zayed and Liwa. Nitrate ion (NO3-) concentration as high as 1000 mg/l in shallow groundwater of UAE was measured west of Al-Kaznah and Liwa areas (Figure 31).

30. 52o 53o 54o 55o 56o Ras Al Khaimah 100 Diba N Gulf of Oman Arabian Gulf 100 50 Dubai 50 200 100 50 25o Kalba 50 100 150 Abu Dhabi Al Ain 250 500 1000 100 150 200 24o 350 250 OMAN 150 UNITED ARAB EMIRATES 450 550 SAUDI 23o 350 250 50 km ARABIA Water Resources - United Arab Emirates Figure 31. Concentration of NO3- in groundwater of the Quaternary sand aquifer in UAE.

31. Water Resources - United Arab Emirates Because of the close correlation between high NO3- contents and the locations of intensive farming (Fig. 32), it seems that the agriculture is the main source of nitrates in shallow groundwater in UAE. Because of the persistent of NO3- in oxygenated systems, the availability of abundant oxygen in the shallow horizons of the Quaternary sand and gravel aquifers contributes to the nitrate contamination problem in the country. WATER RESOURCES MANAGEMENT Sincere efforts are spent to save every drop of water in UAE. Water management efforts include, but not limited to: the use of advanced irrigation technologies, construction of groundwater recharge dams, growing of salt-tolerant crops, development of human resources, application of modern concepts and tools in water resources management.

32. 52o 53o 54o 55o 56o Ras Al Khaimah N Diba Gulf of Oman Arabian Gulf Dubai 25o Kalba Abu Dhabi Al Ain 24o OMAN UNITED ARAB EMIRATES SAUDI 23o 50 km ARABIA Water Resources - United Arab Emirates Figure 32. Distribution of agricultural areas in UAE as in 1985.

33. Water Resources - United Arab Emirates Advanced Agricultural Approaches Irrigation Techniques The Ministry of Agriculture and Fisheries has conducted extensive research during the period 1976-1981 to select the most suitable irrigation technique that suits the water and soil conditions in UAE. Subsequently, modern irrigation networks were provided to the farmers on 50% subsidy basis. By adopting modern irrigation systems up to 60% water could be saved as compared to traditional irrigation methods (Figure 33). In addition to water saving, modern irrigation techniques increased crop productivity. For these reasons, the modern irrigation methods, which was almost non-existing before 1980, now serve 40,455 Hectare out of a total cultivated area of 65,557 Hectare (i.e. 62% of the total cultivated area is now served by modern irrigation).

34. Water Resources - United Arab Emirates Table 11. Number of farms, cultivated areas and areas covered by modern irrigation techniques.

35. Water Resources - United Arab Emirates Figure 33. Modern irrigation techniques.

36. Water Resources - United Arab Emirates Controlled Agriculture The controlled agriculture is to grow crops in green houses when it is difficult to these crops in open fields. The number of green houses in UAE increased from 1678 (covering an area of 56 Hectare) in 1986 to 3960 in 1993 (covering an area of 156 Hectare). Although the production of crops under controlled environments is comparatively expensive but it still economically feasible due to high yield, better-quality products, saving in irrigation water, fertilizers, and pesticides (Figures 34 and 35). Salt-Tolerant Crops Research on a variety of local and foreign crops, which can be grown through salty water, is now being carried out in UAE. A center for research on salt-tolerant crops is also being established.

37. Number of Farms Total Cultivated Area Modern Irrigation Hectare Year Water Resources - United Arab Emirates Figure 34. Number of farms, cultivated areas and areas covered by modern irrigation techniques.

38. Water Resources - United Arab Emirates Green Area Forest Hectare Year Figure 35. Evolution of cultivated area in the United Arab Emirates.

39. Water Resources - United Arab Emirates Recharge Dams There are about 35 groundwater-recharge dams in UAE having a total reservoir capacity of about 75 million m3. These dams have proved to be very effective for recharging groundwater as indicated by the rise in groundwater levels in all monitoring wells constructed at all dam sites (Table 12; Figures 36 and 37). Development of Human Resources The UAE University has proposed to initiate a Master Degree Program in water resources management since 1993. The proposal has been completed and approved, and the program is scheduled to start in September 1999.

40. Flood Volume (MCM) Year Flood Season Water Resources - United Arab Emirates Figure 36. Volume of flood water in during the period 1983-1994.

41. Water Resources - United Arab Emirates Table 12. Volume of flood water retained by some dams in UAE, in million cubic meters.

42. Water Table Rise (m) Dam Name Water Resources - United Arab Emirates Figure 37. Rise of groundwater levels behind some dams in the UAE.

43. Water Resources - United Arab Emirates The purpose of the program is to approach several senior officials in decision-making positions to join the program, learn modern concepts and methodologies in water resources management, and transfer gained skills to their administrations, improving water-related decision. Application of Advanced Management tools For proper water-resources management, historical information is equally important as new data. Establishment of data banks for various meteorological data, hydrological parameters, groundwater levels and results of chemical analysis and recharge and pumping rates.

44. Water Resources - United Arab Emirates All such data are now available as data base on computers. Presentation and interpretation of data for specific purposes can be easily achieved. The use of data to run several water-related models provides extremely powerful water-resources management tools. Development of Human Resources The UAE University has proposed to initiate a Master Degree Program in water resources management since 1993. The proposal has been completed and approved, and the program commenced in September 1999. The purpose of the program is to encourage the participation and enrolment of senior officers responsible for water resources policy development.

45. Water Resources - United Arab Emirates As masters graduates they would learn modern concepts and methodologies in water resources management, and transfer their skills to their administrations, thereby improving the effectiveness of these policies. SUMMARY The UAE rely on non-conventional water resources, in addition to conventional ones, to meet the ever-increasing demands for water. The conventional water resources include seasonal floods, springs, falajes, and groundwater. The non-conventional resources are desalinated water and sewage-treated water. The existing water resources in the UAE include are summarized in Table 1.

47. Water Resources - United Arab Emirates A significant fraction of floodwater is now tapped by 35 groundwater-recharge dams with a total storage capacity of 75 million m3. A few dams are under construction at present and several others are planned for the future. The UAE permanent springs provide about 3 million m3 of water per year. While the discharges of Khatt springs is directly related to rainfall, the discharges of Bu Sukhanah spring (Ain Al Faydah) is independent of rainfall. During the 1984-1991 period, springs salinity increased by 10% to 50% as a result of low rainfall and heavy groundwater pumping in spring recharge areas. High spring-water temperatures (40°C) are related to deep groundwater circulation.

48. Water Resources - United Arab Emirates The high HCO3- concentration in Khatt springs suggests a recent age, whereas the high SO42- content in Bu Sukhanah spring water indicates old age. The Sodium Adsorption Ratio (SAR) of springs water varies between 0.82 and 15.01, indicating that it is not always suitable for irrigation of traditional crops. Despite their limited discharge, falaj water is a renewable resource that is directly related to rainfall. During 1978-1995, the total falaj discharge in the UAE varied between 9 million m3/yr in 1994 and 31.2 million m3/yr in 1982, which represents 2.8 to 9.7% of the total water use in the country. The electrical conductance (EC) of falaj waters varying between 450 micro-Seimens per centimeters (S/cm) in Falaj Asimah (Al Fujairah) and 10,940 S/cm in Falaj Ain Sukhnah (Al Ain).

49. Water Resources - United Arab Emirates An iso-EC map indicates that the salinity of falaj waters is minimal near the watershed of the northern Oman Mountains and increases to the east and west. In the Gheli falajes, the salinity increases with increasing falaj length, but in the Daudi falajes, the salinity is generally low irrespective to the falaj length. According to EC and SAR, water of the Gheli falajes is good for irrigation, whereas the waters of the Daudi and Hadouri falajes are fair to poor for irrigation purposes. The annual recharge for groundwater in UAE is 109 million m3, whereas the present groundwater extraction rate averages 880 million m3/yr. This highly unbalanced situation resulted in aquifer depletion in many areas such as Al Ain and Al Dhaid; a steady increase in groundwater salinity in well fields over the entire country; dryness of many shallow wells; and salt-water intrusion problems.

50. Water Resources - United Arab Emirates Due to excessive groundwater pumping, cones-of-depression ranging from 50 to 100 km in diameter now exist in the Al Dhaid, Hatta, Al Ain and Liwa areas. The northern Oman Mountains in the UAE represent the main recharge area for groundwater. Close to these mountains, low-salinity groundwater (230-1,000 mg/ℓ) exists in the Al Jaww plain, Masafi and Al Shuayb areas. Groundwater salinity of 1,000-3,500 mg/ℓ exist in the Al Ain, Diba, Hatta, Khatt and Al Fujairah areas, whereas salinity of 3,500-6,500 mg/ℓ was recorded in the Ras Al Khaimah, Madinat Zayed, Liwa and Dubai. Groundwater with 10,000 mg/ℓ of dissolved salts is found at Al Dhaid, west and south of Al Ain and Kalba areas. The annual production of desalinated water has increased from 7 million m3 in 1973 to 694 million m3 in 1999.