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Evaluation of coastal problems at Alexandria, Egypt
Ocean & Coastal Management, Vol. 30, Nos 2-3. pp. 281-295, 1996 Copyright © 1996 Elsevier Science Ltd Printed in Northern Ireland. All rights reserved 0964-5691 (95)00066-6 0964-5691/96515.00+0-00 ELSEVIER
Evaluation of coastal problems at Alexandria, Egypt
O m r a n E. Frihy a, Khalid M. D e w i d a r ° & M o h a m e d M. E1 R a e y h "Coastal Research Institute, 15 El Pharaana St., Alexandria, Egypt hInstitute of Graduate Studies and Research, Alexandria University, Egypt
A BS TRA CT Alexandria is the second largest city in Egypt containing more than one third of the national industries and considered as the principal seaside summer resort on the Mediterranean. The coastal zone is presently experiencing two main problems resulting from natural and human activities: beach erosion and pollution. Most of the Alexandria coasts are rocky and have very little or no beach. Significant erosion occurs along most of Alexandria beaches as a result of sediment starvation, coastal processes and sea level rise. One of the most serious threats to the coastal zone comes from inland pollution sources, Mariut lake and sewage pipelines. As a result of increasing population and industrial development, poorly untreated industrial waste, domestic sewage, shipping industry and agricultural runoff are being released to the coast. With the rapid increase in the industries and population, changes in water quality would have potential consequences for the large rapidly growing population of the Alexandria region. Recommendations for environmental recovery and restoration are proposed for preservation of Alexandria resort beaches and harbours in order to facilitate development of environmental and tourist activities. Copyright ~) 1996 Elsevier Science Ltd.
1. I N T R O D U C T I O N Beach erosion and pollution are the most important coastal hazards affecting most of the countries of the Mediterranean Sea. Most of these countries discharge sewage waste into the sea. Sewage pollution affects the fauna and flora as well as swimmers. Some sea foods concentrate 281
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heavy metals in their tissues so they become risky for human consumption. Alexandria waterfront beach is located along the northwestern border of the Nile delta coast (Fig. 1). The city is built on a narrow coastal plain extending from Marakia to Abu Quir. The city lies between Mariut Lake in the south and the Mediterranean Sea in the north. The Alexandria coastal plain is composed of a series of shore-parallel carbonate ridges (about 35 m elevation), which are separated by depressions of shallow lagoons and sabkhas. The coastal plain is backed by inland depressions, semidesert, reclaimed lagoon and Mariut lake to the south. Mariut Lake is situated south of Alexandria and is separated from the sea by a lithified carbonate ridge of Late Pleistocene age. 1 The lake is now artificially divided into many sub-basins by canals and roads. About nine sub-basins were mentioned by Warne and Stanley. 2 Recently, large portions of this lake have been reclaimed and converted to recreation parks. Bearing in mind that Alexandria is the second largest city in Egypt and containing more than one third of the national industries, it is also considered as the principal seaside summer resort on the Mediterranean. About 40% of Egypt's industries are located in Alexandria. The population exceeds 3.5 million, and is predicted to be 5 million by the year 2020, with over 800 inhabitants per km 2 in the outlying country-side. 3 More than one million local summer visitors together with about 3.8 million residents enjoy the summer season at Alexandria every year. The coastal road of Alexandria (Corniche) is protected from the sea by a concrete bulkhead. The beach is interrupted by two major embayments of the Western and Eastern harbours. There are three principal harbours along the Alexandria coast: two commercial harbours; the Western harbour and Abu Quir new harbour. Adjacent to the Western harbour lies the Eastern fishing harbour (Fig. 1). The Western harbour (30 km 2) handles about 85% of the foreign trade of Egypt. The Eastern harbour (25 km 2) is located downtown as a large semiclosed basin to the east of the famous historic Kuaitbay Fort. Beach erosion, rip currents and pollution are the main problems affecting coastal management at Alexandria. The aim of this study is to evaluate these problems. Recommendations are presented to facilitate implementation of a coastal zone management program. 1.1. Beach erosion
The beach sand is composed of medium to coarse biogenic sand varying from loose to fairly well-indurated deposits of quartz, shell fragments,
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heavy minerals and other debris. 4 Most of these sediments are derived from the adjacent Pleistocene carbonate ridges located along the western coast of Alexandria and the local rocky limestone outcrops. The shoreline is generally undulating and interrupted by rocky headlands, forming alternating small embayments and pocket beaches ranging from 0.3 to 1.6 km in length which are separated by headlands. 5 These rocks are mainly oolitic limestone of Pleistocene formation and beachrock. 6 Sea cliffs are common along this coast and form as waves erode carbonate ridges. In contrast, the coast west of El Dekheila is characterized by broad white smooth carbonate beaches. These beaches are backed by a series of shore-parallel dune carbonate ridges. Alexandria beaches are moderately dissipative, characterized by a relatively steep slope of 1:30. Crescentic sand bars are common along Alexandria beaches. These bars are associated with rip currents that cause hazards to swimmers. 7 The inshore and nearshore zones contain outcrops of emerged and submerged rocky islets aligning more or less parallel to the shoreline extending about 300 m into the sea. In most cases, remnants of these rocks form headlands and bottom shoals of the Alexandria beaches. Some beaches, for example, Stanley and Abu Quir, are compartmented by rocky limestone headlands. Most of the shoreline is rocky and has very little or no beach. A maximum beach width of about 100 m exists at most coasts east of Alexandria (Fig. 1). The coastal area up to 100 km west of the Alexandria waterfront to Alamein is presently being developed as new resort beaches (coastal villages). The beach is very wide with an almost straight alignment lacking irregular offshore topography. The beach is composed of oolitic white carbonate sand with minor amounts of quartz grains. Bad management of this beach has created some serious erosional problems and subsequently imbalanced the coastline. Most of Alexandria beaches appear to be experiencing mild erosion with evidence of sand losses, and some beaches have disappeared, while a few are generally stable. The background erosion rate at Alexandria is fairly small, of the order of 20 cm/year based on aerial photos of 1955 and 1983. 6,8 Results show that all beaches are subjected to coastal erosion except a few. The maximum erosion rate of 0.70 m/year is estimated at EL Shatby, Sidi Gaber, and west of El Maamoura beach, whereas a maximum accretion of 0.70 m/year occurs at Sidi Bishr and east of E1 Maamoura beach. 8 Coastal erosion is a complex process involving many natural and human-induced factors. The existing coastal erosion along the delta was generally caused by the marked reduction in the Nile flow and sediment deposited at the
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Rosetta and Damietta mouths due to the construction of dams and barrages across the Nile. This sediment deficiency is combined with the natural reduction of Nile floods due to climatic changes over east Africa. Since closure of the High Aswan D a m in 1964, discharges of sediments at the mouths of the Nile promontories have been reduced to near zero, and subsequently the shoreline has been subjected to dramatic erosion. In the case of Alexandria, E1 Mahmoudyah canal and E1 U m o u m drain were considered as the only source carrying the Nile water and sediments to Alexandria before construction of the Aswan High D a m in 1964 (Fig. 1). In spite of the winter storms that attack beaches, the recession rate at Alexandria is low because of the compartmented nature of the shoreline and the natural protection provided by the rocky sandy limestone islets and shoals. However, the existing erosion may be due in part to the recent reduction of the sediment supply, formerly provided by El Mahmoudyah Canal and E1 U m o u m drain. Wind transport of sand is one of the processes that cause losses in beach sand and subsequent erosion at Alexandria. 8 Annual sand transport by wind was determined at E1 Maamoura beach using a set of sand traps. It is estimated that about 37.7 m3/m of sand are trapped by wind from the beach berm during winter time (five months). Subtracting this amount of sand from the net sand volume losses (450 m 3) estimated from beach profiles yield 412.5 m 3 of eroded sand caused by the action of currents and waves. Archaeological, geological and tidal gauges data indicate that beaches of Alexandria are vulnerable to sea level rise (SLR). Forecasts of beach erosion made on the basis of the so-called Bruun Rule, 9 along 12 beaches at Alexandria, demonstrate that a 0.5 m SLR would cause the disappearance of eight beaches. 1° One of the most serious impacts of sea level rise on Alexandria would be the threat to recreational beach communities. Estimates of losses of land, installations and summer resorts estimated from SLR scenarios at 0.5 m, 1.0 m, 1.5 m and 2.0 m expected dramatic socioeconomic impacts on the waterfront community. Coastal installations include cabins, casinos, and houses, in addition to major government and private housings located close to and along beaches. Large portions of the study area lie below mean sea level including Mariut Lake and its surrounding areas and thus are particularly vulnerable to the expected sea level rise. 1°-12 The estimated rate of relative sea rise/subsidence at Alexandria is considerably small, ranging from 1 to 2 mm/year using tide gauge records ~3and archaeological evidence. ~ A rise in sea level over 30-50 cm could cause Alexandria
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beaches to disappear. 11 Reclaimed lowlands could be flooded, and harbours and roads would require restructuration. 14 As a consequence of the erosion problem, beaches of Alexandria have been protected to prevent further erosion and to provide new recreational sand beaches. Several artificial beach nourishment projects were completed during the last five years at five beaches (Fig. 1). Figure 2 shows a photograph taken at El Asafra beach, immediately after beach replenishment in April 1990. A monitoring program carried out along these beaches using repeated beach profile surveys above and below mean sea level was conducted before and after nourishment? Placement densities ranged from 16 m3/m to 130 m3/m and monitoring periods ranged from 2.4 months to 44.2 months. The annual loss rate of sand from the fill was greatest immediately after the placement ianging from 10 to 20% by volume. The calculated sand losses with time within the survey limits were quite variable. Alexandria projects experienced sand losses ranging between 10% and 70% in a 4-year period. 5 The Eastern harbour is subjected to two main problems. Storm surges in association with spring tides cause considerable trouble to
Fig. 2. Photograph taken in April 1990, immediately after beach replenishment at El Asafra beach. Borrowed sand was obtained from the desert, about 130 km south of Alexandria, by trucking and stockpiling on the native beach. A concrete groin was constructed to compartmentalize the fill sand. The photograph also shows a portion of the Corniche wall.
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adjacent coastal roads. Storm surges raise the sea level by 40 cm, causing overtopping of beaches and structures. Storm waves in winter attack the harbour from the NW direction, with a mean significant height of 75-123 cm. These waves frequently attack the Corniche, causing overtopping of the coastal road around the harbour. '5 To avoid this problem, a proposal was made to create a new beach in conjunction with three groins along the margin of the harbour parallel to the Corniche (Fig. 3). The nourishment processes will be carried out using borrowed material taken from the bottom of the harbour. An amount of 0.74 × 10 6 m 3 has been evaluated as potential coarse-grained sand. Dredging of this sediment from the harbour bottom will of course aid in deepening of the harbour for larger ships. '5
1.2. Beach pollution Like many other areas of the Mediterranean basin, the human pressure at the Alexandria region is creating a number of environmental problems
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affecting the coastal and marine ecosystems. The problem of sewage pollution of Alexandria beaches has become of national concern, since it affects human health as well changes the physico-chemical and biological properties of the water. Several studies have been carried out on water and sediment pollution of the Alexandria coastal zone and the adjacent Mariut Lake. 16-21 More than 18 x 1 0 6 m 3 of untreated sewage and waste waters are annually discharged into the Alexandria water through the local sewerage system. 22 Pollutants are produced from industrial, domestic, anthropogenic and agricultural activities. Land sources of pollution along the Alexandria waterfront have been positioned by E1 Sharkawi ~6 and El Shibini. 23 Prior to 1987, a large part of the city sewage was discharged into the sea through 19 outfalls along the coast (Fig. 4 and Table 1). The major outfall, located to the west at Kauitbay castle, is still used for discharging sewage, whereas 18 minor outfalls have been formerly designed for disposal of rain water during heavy winter rain. As a result of increasing population and industrial development, few of the minor outfalls are used to release raw sewage in non-winter seasons. Under national pressure they are now being closed. The daily sewage discharge in 1980 and the length of these outfalls are listed in Table 1. Heavy metal contents (Fe, Mn, Zn, Cu and Pb) in beach and bottom sediments are detected in sediments in front of these outfalls. 23 In beach sediments, heavy metals range from 1275 to 2530 ppm with an average of 1723 ppm, while in bottom sediments they occur from 1275 to 2828 ppm, with an average of 1881 ppm. The highest levels of heavy metals are detected in sediments from Kauitbay and the Eastern harbour where the main outflow of pollution is located near Kauitbay castle, and systematically decreasing to the east by the effect of a prevailing easterly littoral current. Sediments along the eastern region of Alexandria at Abu Quir bay are also influenced by pollution. Tabia pumping station is the main pollution source in this area. It discharges about 2 x 1 0 6 m3/day from industrial and agricultural wastes coming from Kafr El Dawar (weaving, textile, dying factories) and from local Tabia industries (fertilizer and paper factories). ~6
1.3. Harbour pollution The excessive use of fertilizers and pesticides in the cultivated field in the vicinity of Alexandria is diversely changing the water quality of coastal and groundwater. West of Alexandria, in the vicinity of the Western harbour, El Max pump station discharges about 6 x 106 m3/day
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of agricultural waste from El U m m u m drain and the excess water from Mariut Lake containing wastes of sewage and industrial wastes (Fig. 4). The industry at El Max area which includes chemical and petrochemical, petroleum refineries, cement and textiles and tanneries is forming an additional stress to this area. In response to these industries, the coast at El Max also receives direct industrial wastes. 16 Mercury associated with industrial waste is discharged through the main effluent pipe of the chlorine-alkali plant at E1 Max. The mercury level varies from 140 to 1400/z/g in the nearshore and inner shelf sediments. 24 The coastal zone in this area is also affected by oil pollution from local petroleum companies. Moreover, pollution from oil tankers, about 35 k m west of El Max, usually threaten the coastal water rich sensitive biological system. The coastal water is also polluted by oil spills from land-based petroleum activities, as well as from oil terminals, situated about 35km west of E1 Max. The crude oil delivered to the Mediterranean Sea from the Gulf of Suez through the SOMID pipeline is stored inland in huge tanks, and is subsequently delivered to tankers anchored nearshore. Consequently, oil spills are driven by the predominant littoral drift to the east, polluting the Western harbour. A comparable study of water quality indicates that Alamein water is higher in oxygen concentration by 0.41 ml/l (8% saturation) than the E1 Max region due to pollution. 17 Water pollution resulting from chemical discharges and organic matter
Evaluation of coastal problems at Alexandria
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is also detected using remote sensing at E1 Max, Western harbour and Abu Quir Bay. '9
1.4. Mariut Lake pollution Mariut Lake, with an area of about 90 km% is a shallow brackish water body, the maximum depth is 1.6m, with no natural outlet to the Mediterranean water (Fig. 1). The water supply to the lake is derived from E1 Qalaa drain discharges on the eastern side of the lake and carries industrial and domestic wastes and agricultural runoff. To the south, the El U m u m drain extends across the lake to El Max sub-basin. The E1 U m u m drain carries raw domestic wastwater and agricultural runoff, which is pumped to the sea by the El Max pumping station. About 600000 m3/day of waste water, mostly untreated sewage, industrial and agricultural waste are disposed in Mariut Lake, the eastern part in particular, and in the sea. 16 Large amounts (about 200 000 m3/day) of untreated industrial and domestic wastes with their heavy metals are released directly into the lake via sewage pipes fom the city. 18'25 The lake also receives water from agricultural drainage from the western sector of t h e delta, ground water seepage and rain fall. An agricultural drainage water contribution estimated from 6 to 7.5 million m3/day was reported by Mitwally. 26 This polluted water has greatly increased the organic and nutrient contents and have thus transformed the eastern sector of Mariut into a highly eutrophic lake. This is reflected by the water quality; phosphorus, organic matter, ammonia and hydrogen sulphide have increased, and dissolved oxygen is depleted. 27 In addition to contaminations carried through canals and drains, sediment of the lake and fish body suffers from noxious heavy metals such as mercury. 28'29 Heavy metal concentrations in sediments and water showed a considerable range of variation: copper (0.3560.91mg), cadmium (0.04-0.7), zinc (3.27-63.93), iron (0.39-29.0). Under the influence of pollution, the accumulation of heavy metals and pesticides in water and sediments may cause deleterious effects on the ecosystem of Mariut Lake and cause serious health ramifications. Shell fishing is decimated, the fish catch has declined, and the marsh and lake margins are being dramatically reduced. Alexandria harbours are also heavily polluted, the Eastern harbour is subjected to about 35 × 106 m 3 of sewage and waste water discharging annually from 11 outfalls inside the harbour. 22 Moreover, the bottom sediments of the Western harbour are covered by dark grey to black organic-rich sediments, which are highly concentrated with mercury. 24
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2. CONCLUSIONS AND RECOMMENDATIONS During this century, the Alexandria region has experienced a marked increase in population, which now exceeds 3.5 million. This rapid growth has induced severe problems of domestic pollution in the coastal region. As a consequence of this rapid population and industrial development, untreated or poorly treated industrial waste, domestic sewage, industrial waste and agricultural runoff have moved to and through Mariut Lake south of the city and then released into the sea. This lake has also received a large loading of agricultural runoff through canals and drains. A large amount of the lake water is being pumped to the sea at E1 Max Bay. The poorly untreated domestic and industrial wastwater and agricultural runoff have greatly increased the organic and nutrient contents and thus have transformed the eastern sector of Mariut into highly eutrophic lake. Alexandria coastal areas are of critical economic importance for tourism and fishing activities. Pollutants from industry, runoff and sewage disposal may destroy fish breeding and nursery areas. Continued population growth in the Alexandria coastal zone is projected in the future, with a greatly increasing demand for beachfront development. In this context, management studies are urgently needed to evaluate coastal projects that are envisaged on waterfront beaches. The following recommendations can be taken into consideration in the future development and management of the Alexandria coastal zone: (1) Defence plans against sea level rise and beach erosion have to be conducted project-by-project. This includes regular nourishment for eroded tourist beaches as well as continued periodic renourishment. (2) Maintenance and repair of existing coastal structures as well as artificial beaches to prevent marine inundation into the lowlying regions. (3) Placement of temporary wood fences on the backside of beaches to trap wind-blown sand in winter storms. (4) Exploitation and development of the Eastern harbour by creating a new recreational beach around the Corniche margin. Dredging of borrowed material from the bottom of the harbour during development of this project will also facilitate greater water depth for larger ships. (5) Placement of big signs pointing to locations of beaches having rip currents. (6) Human intervention resulting from building of social clubs along the waterfront of the city, even on rocky unused beaches, would
Evaluation of coastal problems at Alexandria
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truncate littoral current and accelerate beach erosion. (7) Encouraging tourism activities such as: (1) shipping tourism by construction of new marinas west of Alexandria and at Abu Quir Bay, (2) recreational boating, and (3) diving and underwater photography. (8) Monitoring systems for heavy metals in food fish, food crops, waters and sediments in the Mariut Lake and the sea. (9) Pollution recovery and restoration by offshore extension of sewage pipelines. (10) Improve water quality at Alexandria by controlling different types and sources of pollution in Mariut Lake to improve fishery production. (11) Coastal management for future projects at Alexandria should require an environmental impact assessment study (ETA). (12) Establishment of a Management Information System that stores all previous information and data which will help in future development, management and restoration of the Alexandria coastal zone.
REFERENCES 1. Butzer, K.W. On the Pleistocene shorelines of Arab's Gulf Egypt. J. Geology, 68 (1960) 626-637. 2. Warne, A.G. & Stanley, D.J. Late Quaternary evolution of the northwest Nile Delta and adjacent coast in the Alexandria region Egypt. J. Coastal Research, 9 (1993) 26-64. 3. Sestini, G., Implications of climatic changes for the Nile Delta, In: Jeftic, L., Milliman, J. D., & Sestini, G. (eds.), Climatic change and the Mediterranean, pp. 535-601. Edward Arnold, London, 1992. 4. El Wakeel, S.K. & El Sayed, M. Kh., The texture, mineralogy and chemistry of bottom sediments and beach sands from the Alexandria region Egypt. Marine Geology, 27 (1978) 137-160. 5. Frihy, O. E. & Dean, R., Artificial beach nourishment projects on the Egyptian coast. International Coastal Congress ICC Kiel' 92, 84-95, Germany, 1992. 6. El Sayed, M. Kh. Beachrock cementation in Alexandria Egypt. Marine Geology, 80 (1988) 29-35. 7. Nafaa, M.E. & Frihy, O.E. Beach and nearshore features along the dissipative coastline of the Nile delta Egypt. J. Coastal Research, 9 (1993) 654-662. 8. Frihy, O.E., Nasr, S.M., Dewidar, Kh. & El Raey, M. Beach erosion along the coastline of Alexandria Egypt. Acta Oceanologica Simica, China, 13 (1994) 243-251.
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9. Bruun, P. Sea level rise as a cause of shore erosion. Proceedings of the Am. Soc. Cir. Eng., Jour. Water Harbours Division, 88 (1962) 117-130. 10. Dewidar, Kh. M., Seasonal changes of Alexandria coasts by aerial and ground observations (case study: Maamoura beach). M.Sc. Thesis, Institute of Graduate Studies and Research, Alexandria University, 1992, 137p. 11. E1 Sayed, M. Kh., Implications of relative sea level rise on Alexandria. In Impacts of Sea Level Rise on Cites and Regions, pp. 183-189, R. Frassetto (ed). Marsilio Editori, Venice, 1991. 12. El Raey, M., Nasr, S.M., Frihy, O.E., Desouki, S. & Dowidar, Kh. Potential impacts of accelerated sea-level rise on Alexandria Governorate Egypt. J. Coastal Research, Special Issue, 51 (1995) 190-204. 13. Frihy, O.E. Sea level rise and shoreline retreat of the Nile delta promontories Egypt. Natural Hazards, Netherlands, 5 (1992) 65-81. 14. Delft Hydraulics, Implications of relative sea-level rise on the development of the lower Nile delta, Egypt. Pilot study for a quantitative approach. Delft Hydraulics, Report, 1991, 927p. 15. El Fishawi, N.M., Khafagy, A., Fanos, A. & Frihy, O.E. Artificially nourished beach project, Eastern harbour of Alexandria. International Union for Quaternary Research, News Letter, 12 (1990) 20-25. 16. El Sharkawi, F., Aquatic pollution (Alexandria region). Regional Symp. Environ. Stud. (UNARC), pp. 55-71, Alexandria, 1990. 17. Emara, H.I., Iskander, M.F. & Assad, F.N. Chemistry of sea water west of Alexandria. Bull. Inst. Oceanogr. and Fish. ARE, 10 (1984) 35-49. 18. Saad, M. A. H., State of the Egyptian delta lakes, with particular reference to pollution problems. Regional Symp. Environ. Stud. (UNARC), pp. 275-292, Alexandria, 1990. 19. El Raey, M., & Farag, M. M., Remote sensing of coastal water pollution near Alexandria. Regional Symp. Environ. Stud. (UNARC), pp. 468-487, Alexandria, 1990. 20. El Raey, M., Sharaf El Din, S. H., Bignell, K. J. & Farag, M. M., detection and study of pollution over the mediterranean coast of Egypt by CZCS. Regional Symp. Environ. Stud. (UNARC), pp. 488-498, Alexandria, 1990. 21. Nasr, M. S., E1 sokkary, I. H., Fakhry, A. A., & El Shibiny, I. A., Fractionation of some heavy metals in the coastal belt sediments off Alexandria. Regional Symp. Environ. Stud. (UNARC), pp. 415-436, Alexandria, 1990. 22. Abdel Moati, A.R., Aboul-Kassim, T.A., Dowidar, N.M. & E1-Nady, F.E. Carbon fractionation and balance in the Eastern harbor of Alexandria Egypt. Journal of Coastal Research, 7 (1991) 377-386. 23. El Shibiny, I. A., Pollution effects on Alexandria coastal sediments. M.Sc. Thesis, Institute of Graduate Studies and Research, Alexandria University, 1990, 170p. 24. El Sayed, M.Kh. & Halim, Y. Survey of the trace metals pollution in the sediments from the Alexandria region Egypt: I Mercury. Journees Etud. Pollutions, Antalya, 4 (1978) 187-191. 25. Saad, M.A.H., Ezzat, A.A., El Rayis, O.A. & Hafez, H. Occurrence and distribution of chemical pollutants in lake Mariut, Egypt. II. Heavy Metals. Water, Air and Soil Pollution, 16 (1981) 401-407. 26. Mitwally, H., Review of industrial waste disposal in Alexandria. In
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Proceedings of the International Symposium on Management of Industrial Wastewater in Developing Nations, pp. 72-78. Alexandria, Egypt, 1982. 27. Saad, M.A.H., El Rayis, O.A. & Ahdy, H.H. Status of nutrients in Lake Mariut, a delta lakein Egypt suffering from intensive pollution. Marine Pollution Bulletin, 15 (1984) 408-411. 28. El Sokkary, I.H., Contamination of the terrestrial ecosystem by mercury around the industrial complex center of E1 Max, Western Area of Alexandria. In Vernet, J.P. (ed.), International Conference: Heavy Metals in the Environment, pp. 321-324, Edinburgh, CEP 2, 1989. 29. Jean-Luc, L. & Stanley, D.J. Bottom sediment patterns evolving in polluted Mariut Lake Nile Delta, Egypt. Journal of Coastal Research, 10 (1994) 416-439.
Evaluation of coastal problems at Alexandria, Egypt
O m r a n E. Frihy a, Khalid M. D e w i d a r ° & M o h a m e d M. E1 R a e y h "Coastal Research Institute, 15 El Pharaana St., Alexandria, Egypt hInstitute of Graduate Studies and Research, Alexandria University, Egypt
A BS TRA CT Alexandria is the second largest city in Egypt containing more than one third of the national industries and considered as the principal seaside summer resort on the Mediterranean. The coastal zone is presently experiencing two main problems resulting from natural and human activities: beach erosion and pollution. Most of the Alexandria coasts are rocky and have very little or no beach. Significant erosion occurs along most of Alexandria beaches as a result of sediment starvation, coastal processes and sea level rise. One of the most serious threats to the coastal zone comes from inland pollution sources, Mariut lake and sewage pipelines. As a result of increasing population and industrial development, poorly untreated industrial waste, domestic sewage, shipping industry and agricultural runoff are being released to the coast. With the rapid increase in the industries and population, changes in water quality would have potential consequences for the large rapidly growing population of the Alexandria region. Recommendations for environmental recovery and restoration are proposed for preservation of Alexandria resort beaches and harbours in order to facilitate development of environmental and tourist activities. Copyright ~) 1996 Elsevier Science Ltd.
1. I N T R O D U C T I O N Beach erosion and pollution are the most important coastal hazards affecting most of the countries of the Mediterranean Sea. Most of these countries discharge sewage waste into the sea. Sewage pollution affects the fauna and flora as well as swimmers. Some sea foods concentrate 281
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heavy metals in their tissues so they become risky for human consumption. Alexandria waterfront beach is located along the northwestern border of the Nile delta coast (Fig. 1). The city is built on a narrow coastal plain extending from Marakia to Abu Quir. The city lies between Mariut Lake in the south and the Mediterranean Sea in the north. The Alexandria coastal plain is composed of a series of shore-parallel carbonate ridges (about 35 m elevation), which are separated by depressions of shallow lagoons and sabkhas. The coastal plain is backed by inland depressions, semidesert, reclaimed lagoon and Mariut lake to the south. Mariut Lake is situated south of Alexandria and is separated from the sea by a lithified carbonate ridge of Late Pleistocene age. 1 The lake is now artificially divided into many sub-basins by canals and roads. About nine sub-basins were mentioned by Warne and Stanley. 2 Recently, large portions of this lake have been reclaimed and converted to recreation parks. Bearing in mind that Alexandria is the second largest city in Egypt and containing more than one third of the national industries, it is also considered as the principal seaside summer resort on the Mediterranean. About 40% of Egypt's industries are located in Alexandria. The population exceeds 3.5 million, and is predicted to be 5 million by the year 2020, with over 800 inhabitants per km 2 in the outlying country-side. 3 More than one million local summer visitors together with about 3.8 million residents enjoy the summer season at Alexandria every year. The coastal road of Alexandria (Corniche) is protected from the sea by a concrete bulkhead. The beach is interrupted by two major embayments of the Western and Eastern harbours. There are three principal harbours along the Alexandria coast: two commercial harbours; the Western harbour and Abu Quir new harbour. Adjacent to the Western harbour lies the Eastern fishing harbour (Fig. 1). The Western harbour (30 km 2) handles about 85% of the foreign trade of Egypt. The Eastern harbour (25 km 2) is located downtown as a large semiclosed basin to the east of the famous historic Kuaitbay Fort. Beach erosion, rip currents and pollution are the main problems affecting coastal management at Alexandria. The aim of this study is to evaluate these problems. Recommendations are presented to facilitate implementation of a coastal zone management program. 1.1. Beach erosion
The beach sand is composed of medium to coarse biogenic sand varying from loose to fairly well-indurated deposits of quartz, shell fragments,
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heavy minerals and other debris. 4 Most of these sediments are derived from the adjacent Pleistocene carbonate ridges located along the western coast of Alexandria and the local rocky limestone outcrops. The shoreline is generally undulating and interrupted by rocky headlands, forming alternating small embayments and pocket beaches ranging from 0.3 to 1.6 km in length which are separated by headlands. 5 These rocks are mainly oolitic limestone of Pleistocene formation and beachrock. 6 Sea cliffs are common along this coast and form as waves erode carbonate ridges. In contrast, the coast west of El Dekheila is characterized by broad white smooth carbonate beaches. These beaches are backed by a series of shore-parallel dune carbonate ridges. Alexandria beaches are moderately dissipative, characterized by a relatively steep slope of 1:30. Crescentic sand bars are common along Alexandria beaches. These bars are associated with rip currents that cause hazards to swimmers. 7 The inshore and nearshore zones contain outcrops of emerged and submerged rocky islets aligning more or less parallel to the shoreline extending about 300 m into the sea. In most cases, remnants of these rocks form headlands and bottom shoals of the Alexandria beaches. Some beaches, for example, Stanley and Abu Quir, are compartmented by rocky limestone headlands. Most of the shoreline is rocky and has very little or no beach. A maximum beach width of about 100 m exists at most coasts east of Alexandria (Fig. 1). The coastal area up to 100 km west of the Alexandria waterfront to Alamein is presently being developed as new resort beaches (coastal villages). The beach is very wide with an almost straight alignment lacking irregular offshore topography. The beach is composed of oolitic white carbonate sand with minor amounts of quartz grains. Bad management of this beach has created some serious erosional problems and subsequently imbalanced the coastline. Most of Alexandria beaches appear to be experiencing mild erosion with evidence of sand losses, and some beaches have disappeared, while a few are generally stable. The background erosion rate at Alexandria is fairly small, of the order of 20 cm/year based on aerial photos of 1955 and 1983. 6,8 Results show that all beaches are subjected to coastal erosion except a few. The maximum erosion rate of 0.70 m/year is estimated at EL Shatby, Sidi Gaber, and west of El Maamoura beach, whereas a maximum accretion of 0.70 m/year occurs at Sidi Bishr and east of E1 Maamoura beach. 8 Coastal erosion is a complex process involving many natural and human-induced factors. The existing coastal erosion along the delta was generally caused by the marked reduction in the Nile flow and sediment deposited at the
Evaluation of coastal problems at Alexandria
285
Rosetta and Damietta mouths due to the construction of dams and barrages across the Nile. This sediment deficiency is combined with the natural reduction of Nile floods due to climatic changes over east Africa. Since closure of the High Aswan D a m in 1964, discharges of sediments at the mouths of the Nile promontories have been reduced to near zero, and subsequently the shoreline has been subjected to dramatic erosion. In the case of Alexandria, E1 Mahmoudyah canal and E1 U m o u m drain were considered as the only source carrying the Nile water and sediments to Alexandria before construction of the Aswan High D a m in 1964 (Fig. 1). In spite of the winter storms that attack beaches, the recession rate at Alexandria is low because of the compartmented nature of the shoreline and the natural protection provided by the rocky sandy limestone islets and shoals. However, the existing erosion may be due in part to the recent reduction of the sediment supply, formerly provided by El Mahmoudyah Canal and E1 U m o u m drain. Wind transport of sand is one of the processes that cause losses in beach sand and subsequent erosion at Alexandria. 8 Annual sand transport by wind was determined at E1 Maamoura beach using a set of sand traps. It is estimated that about 37.7 m3/m of sand are trapped by wind from the beach berm during winter time (five months). Subtracting this amount of sand from the net sand volume losses (450 m 3) estimated from beach profiles yield 412.5 m 3 of eroded sand caused by the action of currents and waves. Archaeological, geological and tidal gauges data indicate that beaches of Alexandria are vulnerable to sea level rise (SLR). Forecasts of beach erosion made on the basis of the so-called Bruun Rule, 9 along 12 beaches at Alexandria, demonstrate that a 0.5 m SLR would cause the disappearance of eight beaches. 1° One of the most serious impacts of sea level rise on Alexandria would be the threat to recreational beach communities. Estimates of losses of land, installations and summer resorts estimated from SLR scenarios at 0.5 m, 1.0 m, 1.5 m and 2.0 m expected dramatic socioeconomic impacts on the waterfront community. Coastal installations include cabins, casinos, and houses, in addition to major government and private housings located close to and along beaches. Large portions of the study area lie below mean sea level including Mariut Lake and its surrounding areas and thus are particularly vulnerable to the expected sea level rise. 1°-12 The estimated rate of relative sea rise/subsidence at Alexandria is considerably small, ranging from 1 to 2 mm/year using tide gauge records ~3and archaeological evidence. ~ A rise in sea level over 30-50 cm could cause Alexandria
286
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beaches to disappear. 11 Reclaimed lowlands could be flooded, and harbours and roads would require restructuration. 14 As a consequence of the erosion problem, beaches of Alexandria have been protected to prevent further erosion and to provide new recreational sand beaches. Several artificial beach nourishment projects were completed during the last five years at five beaches (Fig. 1). Figure 2 shows a photograph taken at El Asafra beach, immediately after beach replenishment in April 1990. A monitoring program carried out along these beaches using repeated beach profile surveys above and below mean sea level was conducted before and after nourishment? Placement densities ranged from 16 m3/m to 130 m3/m and monitoring periods ranged from 2.4 months to 44.2 months. The annual loss rate of sand from the fill was greatest immediately after the placement ianging from 10 to 20% by volume. The calculated sand losses with time within the survey limits were quite variable. Alexandria projects experienced sand losses ranging between 10% and 70% in a 4-year period. 5 The Eastern harbour is subjected to two main problems. Storm surges in association with spring tides cause considerable trouble to
Fig. 2. Photograph taken in April 1990, immediately after beach replenishment at El Asafra beach. Borrowed sand was obtained from the desert, about 130 km south of Alexandria, by trucking and stockpiling on the native beach. A concrete groin was constructed to compartmentalize the fill sand. The photograph also shows a portion of the Corniche wall.
287
Evaluation of coastal problems at Alexandria
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adjacent coastal roads. Storm surges raise the sea level by 40 cm, causing overtopping of beaches and structures. Storm waves in winter attack the harbour from the NW direction, with a mean significant height of 75-123 cm. These waves frequently attack the Corniche, causing overtopping of the coastal road around the harbour. '5 To avoid this problem, a proposal was made to create a new beach in conjunction with three groins along the margin of the harbour parallel to the Corniche (Fig. 3). The nourishment processes will be carried out using borrowed material taken from the bottom of the harbour. An amount of 0.74 × 10 6 m 3 has been evaluated as potential coarse-grained sand. Dredging of this sediment from the harbour bottom will of course aid in deepening of the harbour for larger ships. '5
1.2. Beach pollution Like many other areas of the Mediterranean basin, the human pressure at the Alexandria region is creating a number of environmental problems
288
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affecting the coastal and marine ecosystems. The problem of sewage pollution of Alexandria beaches has become of national concern, since it affects human health as well changes the physico-chemical and biological properties of the water. Several studies have been carried out on water and sediment pollution of the Alexandria coastal zone and the adjacent Mariut Lake. 16-21 More than 18 x 1 0 6 m 3 of untreated sewage and waste waters are annually discharged into the Alexandria water through the local sewerage system. 22 Pollutants are produced from industrial, domestic, anthropogenic and agricultural activities. Land sources of pollution along the Alexandria waterfront have been positioned by E1 Sharkawi ~6 and El Shibini. 23 Prior to 1987, a large part of the city sewage was discharged into the sea through 19 outfalls along the coast (Fig. 4 and Table 1). The major outfall, located to the west at Kauitbay castle, is still used for discharging sewage, whereas 18 minor outfalls have been formerly designed for disposal of rain water during heavy winter rain. As a result of increasing population and industrial development, few of the minor outfalls are used to release raw sewage in non-winter seasons. Under national pressure they are now being closed. The daily sewage discharge in 1980 and the length of these outfalls are listed in Table 1. Heavy metal contents (Fe, Mn, Zn, Cu and Pb) in beach and bottom sediments are detected in sediments in front of these outfalls. 23 In beach sediments, heavy metals range from 1275 to 2530 ppm with an average of 1723 ppm, while in bottom sediments they occur from 1275 to 2828 ppm, with an average of 1881 ppm. The highest levels of heavy metals are detected in sediments from Kauitbay and the Eastern harbour where the main outflow of pollution is located near Kauitbay castle, and systematically decreasing to the east by the effect of a prevailing easterly littoral current. Sediments along the eastern region of Alexandria at Abu Quir bay are also influenced by pollution. Tabia pumping station is the main pollution source in this area. It discharges about 2 x 1 0 6 m3/day from industrial and agricultural wastes coming from Kafr El Dawar (weaving, textile, dying factories) and from local Tabia industries (fertilizer and paper factories). ~6
1.3. Harbour pollution The excessive use of fertilizers and pesticides in the cultivated field in the vicinity of Alexandria is diversely changing the water quality of coastal and groundwater. West of Alexandria, in the vicinity of the Western harbour, El Max pump station discharges about 6 x 106 m3/day
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of agricultural waste from El U m m u m drain and the excess water from Mariut Lake containing wastes of sewage and industrial wastes (Fig. 4). The industry at El Max area which includes chemical and petrochemical, petroleum refineries, cement and textiles and tanneries is forming an additional stress to this area. In response to these industries, the coast at El Max also receives direct industrial wastes. 16 Mercury associated with industrial waste is discharged through the main effluent pipe of the chlorine-alkali plant at E1 Max. The mercury level varies from 140 to 1400/z/g in the nearshore and inner shelf sediments. 24 The coastal zone in this area is also affected by oil pollution from local petroleum companies. Moreover, pollution from oil tankers, about 35 k m west of El Max, usually threaten the coastal water rich sensitive biological system. The coastal water is also polluted by oil spills from land-based petroleum activities, as well as from oil terminals, situated about 35km west of E1 Max. The crude oil delivered to the Mediterranean Sea from the Gulf of Suez through the SOMID pipeline is stored inland in huge tanks, and is subsequently delivered to tankers anchored nearshore. Consequently, oil spills are driven by the predominant littoral drift to the east, polluting the Western harbour. A comparable study of water quality indicates that Alamein water is higher in oxygen concentration by 0.41 ml/l (8% saturation) than the E1 Max region due to pollution. 17 Water pollution resulting from chemical discharges and organic matter
Evaluation of coastal problems at Alexandria
291
is also detected using remote sensing at E1 Max, Western harbour and Abu Quir Bay. '9
1.4. Mariut Lake pollution Mariut Lake, with an area of about 90 km% is a shallow brackish water body, the maximum depth is 1.6m, with no natural outlet to the Mediterranean water (Fig. 1). The water supply to the lake is derived from E1 Qalaa drain discharges on the eastern side of the lake and carries industrial and domestic wastes and agricultural runoff. To the south, the El U m u m drain extends across the lake to El Max sub-basin. The E1 U m u m drain carries raw domestic wastwater and agricultural runoff, which is pumped to the sea by the El Max pumping station. About 600000 m3/day of waste water, mostly untreated sewage, industrial and agricultural waste are disposed in Mariut Lake, the eastern part in particular, and in the sea. 16 Large amounts (about 200 000 m3/day) of untreated industrial and domestic wastes with their heavy metals are released directly into the lake via sewage pipes fom the city. 18'25 The lake also receives water from agricultural drainage from the western sector of t h e delta, ground water seepage and rain fall. An agricultural drainage water contribution estimated from 6 to 7.5 million m3/day was reported by Mitwally. 26 This polluted water has greatly increased the organic and nutrient contents and have thus transformed the eastern sector of Mariut into a highly eutrophic lake. This is reflected by the water quality; phosphorus, organic matter, ammonia and hydrogen sulphide have increased, and dissolved oxygen is depleted. 27 In addition to contaminations carried through canals and drains, sediment of the lake and fish body suffers from noxious heavy metals such as mercury. 28'29 Heavy metal concentrations in sediments and water showed a considerable range of variation: copper (0.3560.91mg), cadmium (0.04-0.7), zinc (3.27-63.93), iron (0.39-29.0). Under the influence of pollution, the accumulation of heavy metals and pesticides in water and sediments may cause deleterious effects on the ecosystem of Mariut Lake and cause serious health ramifications. Shell fishing is decimated, the fish catch has declined, and the marsh and lake margins are being dramatically reduced. Alexandria harbours are also heavily polluted, the Eastern harbour is subjected to about 35 × 106 m 3 of sewage and waste water discharging annually from 11 outfalls inside the harbour. 22 Moreover, the bottom sediments of the Western harbour are covered by dark grey to black organic-rich sediments, which are highly concentrated with mercury. 24
292
o. E. Frihy et al.
2. CONCLUSIONS AND RECOMMENDATIONS During this century, the Alexandria region has experienced a marked increase in population, which now exceeds 3.5 million. This rapid growth has induced severe problems of domestic pollution in the coastal region. As a consequence of this rapid population and industrial development, untreated or poorly treated industrial waste, domestic sewage, industrial waste and agricultural runoff have moved to and through Mariut Lake south of the city and then released into the sea. This lake has also received a large loading of agricultural runoff through canals and drains. A large amount of the lake water is being pumped to the sea at E1 Max Bay. The poorly untreated domestic and industrial wastwater and agricultural runoff have greatly increased the organic and nutrient contents and thus have transformed the eastern sector of Mariut into highly eutrophic lake. Alexandria coastal areas are of critical economic importance for tourism and fishing activities. Pollutants from industry, runoff and sewage disposal may destroy fish breeding and nursery areas. Continued population growth in the Alexandria coastal zone is projected in the future, with a greatly increasing demand for beachfront development. In this context, management studies are urgently needed to evaluate coastal projects that are envisaged on waterfront beaches. The following recommendations can be taken into consideration in the future development and management of the Alexandria coastal zone: (1) Defence plans against sea level rise and beach erosion have to be conducted project-by-project. This includes regular nourishment for eroded tourist beaches as well as continued periodic renourishment. (2) Maintenance and repair of existing coastal structures as well as artificial beaches to prevent marine inundation into the lowlying regions. (3) Placement of temporary wood fences on the backside of beaches to trap wind-blown sand in winter storms. (4) Exploitation and development of the Eastern harbour by creating a new recreational beach around the Corniche margin. Dredging of borrowed material from the bottom of the harbour during development of this project will also facilitate greater water depth for larger ships. (5) Placement of big signs pointing to locations of beaches having rip currents. (6) Human intervention resulting from building of social clubs along the waterfront of the city, even on rocky unused beaches, would
Evaluation of coastal problems at Alexandria
293
truncate littoral current and accelerate beach erosion. (7) Encouraging tourism activities such as: (1) shipping tourism by construction of new marinas west of Alexandria and at Abu Quir Bay, (2) recreational boating, and (3) diving and underwater photography. (8) Monitoring systems for heavy metals in food fish, food crops, waters and sediments in the Mariut Lake and the sea. (9) Pollution recovery and restoration by offshore extension of sewage pipelines. (10) Improve water quality at Alexandria by controlling different types and sources of pollution in Mariut Lake to improve fishery production. (11) Coastal management for future projects at Alexandria should require an environmental impact assessment study (ETA). (12) Establishment of a Management Information System that stores all previous information and data which will help in future development, management and restoration of the Alexandria coastal zone.
REFERENCES 1. Butzer, K.W. On the Pleistocene shorelines of Arab's Gulf Egypt. J. Geology, 68 (1960) 626-637. 2. Warne, A.G. & Stanley, D.J. Late Quaternary evolution of the northwest Nile Delta and adjacent coast in the Alexandria region Egypt. J. Coastal Research, 9 (1993) 26-64. 3. Sestini, G., Implications of climatic changes for the Nile Delta, In: Jeftic, L., Milliman, J. D., & Sestini, G. (eds.), Climatic change and the Mediterranean, pp. 535-601. Edward Arnold, London, 1992. 4. El Wakeel, S.K. & El Sayed, M. Kh., The texture, mineralogy and chemistry of bottom sediments and beach sands from the Alexandria region Egypt. Marine Geology, 27 (1978) 137-160. 5. Frihy, O. E. & Dean, R., Artificial beach nourishment projects on the Egyptian coast. International Coastal Congress ICC Kiel' 92, 84-95, Germany, 1992. 6. El Sayed, M. Kh. Beachrock cementation in Alexandria Egypt. Marine Geology, 80 (1988) 29-35. 7. Nafaa, M.E. & Frihy, O.E. Beach and nearshore features along the dissipative coastline of the Nile delta Egypt. J. Coastal Research, 9 (1993) 654-662. 8. Frihy, O.E., Nasr, S.M., Dewidar, Kh. & El Raey, M. Beach erosion along the coastline of Alexandria Egypt. Acta Oceanologica Simica, China, 13 (1994) 243-251.
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9. Bruun, P. Sea level rise as a cause of shore erosion. Proceedings of the Am. Soc. Cir. Eng., Jour. Water Harbours Division, 88 (1962) 117-130. 10. Dewidar, Kh. M., Seasonal changes of Alexandria coasts by aerial and ground observations (case study: Maamoura beach). M.Sc. Thesis, Institute of Graduate Studies and Research, Alexandria University, 1992, 137p. 11. E1 Sayed, M. Kh., Implications of relative sea level rise on Alexandria. In Impacts of Sea Level Rise on Cites and Regions, pp. 183-189, R. Frassetto (ed). Marsilio Editori, Venice, 1991. 12. El Raey, M., Nasr, S.M., Frihy, O.E., Desouki, S. & Dowidar, Kh. Potential impacts of accelerated sea-level rise on Alexandria Governorate Egypt. J. Coastal Research, Special Issue, 51 (1995) 190-204. 13. Frihy, O.E. Sea level rise and shoreline retreat of the Nile delta promontories Egypt. Natural Hazards, Netherlands, 5 (1992) 65-81. 14. Delft Hydraulics, Implications of relative sea-level rise on the development of the lower Nile delta, Egypt. Pilot study for a quantitative approach. Delft Hydraulics, Report, 1991, 927p. 15. El Fishawi, N.M., Khafagy, A., Fanos, A. & Frihy, O.E. Artificially nourished beach project, Eastern harbour of Alexandria. International Union for Quaternary Research, News Letter, 12 (1990) 20-25. 16. El Sharkawi, F., Aquatic pollution (Alexandria region). Regional Symp. Environ. Stud. (UNARC), pp. 55-71, Alexandria, 1990. 17. Emara, H.I., Iskander, M.F. & Assad, F.N. Chemistry of sea water west of Alexandria. Bull. Inst. Oceanogr. and Fish. ARE, 10 (1984) 35-49. 18. Saad, M. A. H., State of the Egyptian delta lakes, with particular reference to pollution problems. Regional Symp. Environ. Stud. (UNARC), pp. 275-292, Alexandria, 1990. 19. El Raey, M., & Farag, M. M., Remote sensing of coastal water pollution near Alexandria. Regional Symp. Environ. Stud. (UNARC), pp. 468-487, Alexandria, 1990. 20. El Raey, M., Sharaf El Din, S. H., Bignell, K. J. & Farag, M. M., detection and study of pollution over the mediterranean coast of Egypt by CZCS. Regional Symp. Environ. Stud. (UNARC), pp. 488-498, Alexandria, 1990. 21. Nasr, M. S., E1 sokkary, I. H., Fakhry, A. A., & El Shibiny, I. A., Fractionation of some heavy metals in the coastal belt sediments off Alexandria. Regional Symp. Environ. Stud. (UNARC), pp. 415-436, Alexandria, 1990. 22. Abdel Moati, A.R., Aboul-Kassim, T.A., Dowidar, N.M. & E1-Nady, F.E. Carbon fractionation and balance in the Eastern harbor of Alexandria Egypt. Journal of Coastal Research, 7 (1991) 377-386. 23. El Shibiny, I. A., Pollution effects on Alexandria coastal sediments. M.Sc. Thesis, Institute of Graduate Studies and Research, Alexandria University, 1990, 170p. 24. El Sayed, M.Kh. & Halim, Y. Survey of the trace metals pollution in the sediments from the Alexandria region Egypt: I Mercury. Journees Etud. Pollutions, Antalya, 4 (1978) 187-191. 25. Saad, M.A.H., Ezzat, A.A., El Rayis, O.A. & Hafez, H. Occurrence and distribution of chemical pollutants in lake Mariut, Egypt. II. Heavy Metals. Water, Air and Soil Pollution, 16 (1981) 401-407. 26. Mitwally, H., Review of industrial waste disposal in Alexandria. In
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Proceedings of the International Symposium on Management of Industrial Wastewater in Developing Nations, pp. 72-78. Alexandria, Egypt, 1982. 27. Saad, M.A.H., El Rayis, O.A. & Ahdy, H.H. Status of nutrients in Lake Mariut, a delta lakein Egypt suffering from intensive pollution. Marine Pollution Bulletin, 15 (1984) 408-411. 28. El Sokkary, I.H., Contamination of the terrestrial ecosystem by mercury around the industrial complex center of E1 Max, Western Area of Alexandria. In Vernet, J.P. (ed.), International Conference: Heavy Metals in the Environment, pp. 321-324, Edinburgh, CEP 2, 1989. 29. Jean-Luc, L. & Stanley, D.J. Bottom sediment patterns evolving in polluted Mariut Lake Nile Delta, Egypt. Journal of Coastal Research, 10 (1994) 416-439.