The Nile Delta

The Nile Delta and its coastal zone are populated regions in Egypt and contain a variety of development activities. Those human activities which provide income and source of life to many also generate constraints to Nile Delta region. This introductory chapter presents a brief biography of the Nile Delta and presents a comprehensive and concise summary of recent research related to challenges in Nile Delta regions. In addition, possible opportunities are included. Five main themes of research, namely, land use challenge, coastal erosion, potential impacts of sea level rise (SLR), water quality deterioration, and seawater intrusion, are reviewed. Also, the chapter summarizes some suggested/proposed and/or implemented adaptation and/or mitigation acts for each challenge. The article concluded that further integrated research based on solid reliable field databases is urgently needed.

During the geological history, the Nile developed his valley and built up the Delta. The floodplain extends from El-Tina Plain east of Port Said city to Alexandria city in the west. The contour map shows that the surface of the eastern Delta is higher than the western surface; this leads to the formation of many depressions and lakes in the northwestern of the Delta. Lake Manzala is located at the northeastern corner of the Nile Delta. Within the Manzala lagoon, there are many archaeological sites, the most important being Tall Tanis which is located 6 km south of Port Said and covers an area of about 8 km². It was a seaport and center of commerce of some importance. It is the remains of the settlements such as the water tanks and the textile factory dated to the early Islamic era that might have been destroyed or demolished by the outlaws.

Economic and social activities in the Tanis region were influenced by three main water bodies throughout its history: the Mediterranean Sea, the River Nile throughout the Tanitic ancient Nile Delta Branch, and Lake Manzala which extended to the south and southwest of the site.

The water supply and storage systems relied on the annual Nile flood, during which the lake became potable; water was collected from the waterway by using shaduf or saqiya and stored in tanks or cisterns on the island for use throughout the rest of the year. There are two types of water tanks used to store the Nile water. The big tanks and their connecting channels/ditches may indicate that it was controlled by authorities as public facilities, while the small foundations were endowed by the private sectors.

Groundwater is the main source for domestic, industrial, and agriculture uses in most of the new reclaimed areas in the western Nile Delta region, which affects the groundwater quality. The hydrochemistry of major ions (K⁺, Na⁺, Mg²⁺, Ca²⁺, Cl⁻, SO₄ ²⁻, HCO₃ ⁻, CO₃ ²⁻) together with trace elements (Fe, Mn, Zn, Pb, Cd, Cr, Cu, Ni) has been used to constrain the hydrochemical characteristics of groundwater, western Nile Delta aquifers. The total of 108 groundwater wells, varying in depth from 27.5 to 120 m, have been examined and sampled to carry out the physico-chemical parameters and chemical compositions of the groundwater and to obtain additional information on the possible interaction with the Nile water. This chapter deals also with water quality and contamination with nutrients (NO₃ ⁻, PO₄ ²⁻, NH₄ ⁺) and trace elements (heavy metals). The groundwater is slightly alkaline with pH’s ranging from 7.11 to 8.65 with an average of 7.9. The salinity of the groundwater as a total dissolved solid (TDS) ranges from 430 mg/L (freshwater) in some parts of the Quaternary aquifer to 24,407 mg/L (saline water) in the northwestern Nile Delta with an average of 2,705 mg/L (brackish water). It increases gradually north- and westwards due to seawater intrusion and mixing with the Miocene aquifer, respectively. The freshwater is mainly concentrated in the central-eastern part, close to Rosetta branch. The chloride (Cl⁻) and sulfate (SO₄ ²⁻) ions acquire the higher concentrations of the anions, while sodium (Na⁺), calcium (Ca²⁺), and magnesium (Mg²⁺) acquire the higher concentrations of the cations. The concentrations of the major ions are higher than the maximum standard limits, according to the World Health Organization (WHO, International program on chemical safety). The nutrient content of phosphates is also higher than the maximum standard values, while nitrate is in the critical level. The maximum concentration of nutrients was mainly recorded in the old cultivated lands, indicating the contamination from irrigation water. The concentrations of the trace elements are lower than the standard limits except for iron, manganese, and nickel. The hydrochemical composition reflects the Na-HCO₃ water type for the Quaternary aquifer, indicating recent meteoric water. Another major water type (Na-Cl) is recorded in the high salinity areas of northern and western parts. According to the US Salinity Laboratory diagram, most of the groundwaters are located in the high salinity and low sodium hazard zone. The groundwater has <1.25 meq/L RSC, which is good quality and suitable for using in irrigation for all types of soils.

Groundwater is a major portion of the world’s freshwater resources. One of the main challenges facing the sustainable development of Egypt is the need for better management of its limited freshwater resources. Groundwater in Egypt exists in the Nile Valley, Nile Delta, Western Desert Oases, and Sinai Peninsula. Hydrogeological mapping of groundwater resources is one of the main tools for the controlled development of groundwater resources. Remote sensing surface indicators of groundwater provide useful data where practical classical alternatives are not available. Integrated remote sensing and GIS are widely used in groundwater mapping. Locating potential groundwater targets is becoming more convenient, efficient, and cost effective than invasive methods with the advent of a number of satellite images. The nature of remote sensing-based groundwater exploration is to delineate all possible features connected with localization of groundwater. Remote sensing data supports decisions related to sustainable development and groundwater management.

Groundwater (GW) is an important source of drinking and irrigation water in Egypt, especially in some areas where the surface water is insufficient or unavailable. The present study presents the multivariate statistical analysis of groundwater quality of the western Nile Delta (ND) aquifer in order to investigate the factors controlling the groundwater quality. Also, it presents the suitability of groundwater in the western ND for drinking and irrigation. The available data, of 108 GW wells, includes 21 physicochemical parameters for each well (GW sample), viz., EC, TH, TDS, pH, Ca, Mg, Na, K, CL, SO₄, HCO₃, CO₃, Fe, Mn, Zn, Cu, Pb, Cd, Cr, NO₃, and NH₄. Nineteen physicochemical parameters are used as inputs for multivariate analysis. The World Health Organization (WHO) and Egyptian standards (ES) were used as reference standards for the suitability of water for drinking purposes. TDS, SAR, Na %, RSC, Mg %, PI %, KI, CRI, and CR were used to evaluate groundwater suitability for irrigation. ArcGIS was utilized to detect and visualize the spatial classification maps of different parameters. Multivariate analysis showed the existence of up to four significant factors which account for 77.0% of the total variance of hydrochemistry data. The computed water quality index (WQI) shows that 45.37% and 66.67% of GW wells fall in good drinking water categories according to WHO and ES, respectively. According to values of TDS, RSC, SAR, and PI, more than 58.83% of groundwater wells are suitable for irrigation. It is recommended to take the necessary actions to control the pollution sources of groundwater in western ND.

Egypt’s population is estimated at 90 million people. Egypt covers an area of 1,001,449 km² that is mostly desert (Sahara). Only 6% of Egypt’s area is inhabited. Most of the people live in the Nile Delta and the narrow Nile Valley. The majority of Egyptians (43.3%) live in Lower Egypt (north of the country), whereas 37.1% live in Upper Egypt (south).

The total agricultural land area in Egypt is about 3.85 million ha, accounting for almost 3.5% of the total area. Only 5.4% of the land resources in Egypt are qualified as excellent, and the rest is either poor or of low quality (mainly due to salinity problems). The total area cropped annually increased from 4.6 million ha in 1982 to 6.5 million ha in 2003 due to increased cropping intensity, till it reached 6.9 million ha (16.5 million feddan) in year 2009. That is because of the variety between annual and permanent crops which made it possible to permit up to three harvests per year.

In this chapter, the description of Nile Delta was presented including geography, climate, and geology. The types and physical properties of groundwater aquifers including the Nile Delta aquifer were covered. The principles of groundwater contamination with organic and inorganic contaminants including nutrients such as nitrogen, phosphorous, and sulfur were illustrated. The physicochemical reactions (hydrolysis, oxidation–reduction, biodegradation, adsorption, and volatilization) are described in detail.

In addition, information about the agroecological zones and farming systems, particularly in regard to agricultural suitability, was provided. The agricultural production systems, including fertilizer requirements and crop needs, were also described. The recommended rates of fertilizer for the main crops in Egypt were given. Besides, the summarization of several studies, results for the determination of the most suitable time and proper method of fertilizer application on various crops are supplied.

On the other hand, the advection–dispersion equation which describes the contaminants transport process is presented with illustration for the advection, dispersion, and adsorption phenomenon. Different numerical models including finite difference method (FDM), finite element method (FEM), and boundary element method are covered. Also, the most popular computer codes Modular Finite-Difference Groundwater Flow Model (MODFLOW), MT3DMS, Groundwater Modeling System (GMS), Soil and Water Assessment Tool (SWAT), Finite Element Subsurface Flow and Transport Simulation System (FEFLOW), and HYDRUS are presented.

Moreover, the groundwater modeling systems (MODFLOW and MT3DMS) are used to simulate three-dimensional groundwater flow and NO₃ ⁻ transportation processes in El-Menoufia Governorate as a case study, located in the central region of the Nile Delta aquifer. The results highlight areas of groundwater contamination by NO₃ ⁻, which occurred at 40 m depth because of the significant loads and method of nitrogen fertilizer application.

Groundwater quality is increasingly being threatened by agricultural, urban, and industrial wastes, which leach or are injected into underlying aquifers. Groundwater pollution can occur from on-site sanitation systems, landfills, effluent from wastewater treatment plants, leaking sewers, petroleum stations, or from over-application of fertilizers in agriculture. Pollution can also occur from naturally occurring contaminants, such as arsenic or fluoride. Aquifer vulnerability to pollution is mainly related to the use of excess fertilizers, due to the growing industrial activities; sewage effluent disposal; and landfill leaching, gasoline plumes, and nuclear wastes. Contaminants found in groundwater cover a broad range of physical, inorganic chemical, organic chemical, bacteriological, and radioactive parameters. Different mechanisms influence the transport of pollutants (e.g., diffusion, adsorption, precipitation, decay, in the groundwater). Movement of water and dispersion within the aquifer spreads the pollutant over a wider area. Once the groundwater is contaminated, its quality cannot be restored by stopping the pollutants at the source. Groundwater monitoring networks are constructed to perform site monitoring, ambient groundwater quality monitoring, and to collect data to develop groundwater aquifers, or initiate site remediation. The locations and depths of monitoring wells are the most important aspects of a monitoring network. Groundwater contaminants are subjected to dispersion and diffusion. The water quality index (WQI) is one of the most effective tools to communicate information on the quality of water to the concerned citizens and policy makers. Mathematical modeling techniques have been successfully utilized for simulating groundwater movement and solute transport mechanism. Hydrochemical and isotope tracer methods have been successfully used to assess pollution sources and concentrations in groundwater problems. Selection of the appropriate remedial technology is based on site-specific factors and often takes into account cleanup goals based on predicted potential risk to human health and the environment. Contaminated site remediation is generally difficult, time consuming, and expensive. Groundwater remediation is the cleanup of contaminated groundwater to levels that are in compliance with regulatory limits set by the Environmental Protection Agency (EPA). Recently, many activities have had an impact on eutrophication, contamination status, ecological value, and the environmental condition of the Nile Delta region. This chapter aims to identify problems, knowledge gaps, and needs that are deemed important to improving groundwater monitoring, modeling, and remediation in the Nile Delta.

The cultivated area of the Nile Delta is 4.354 million feddan (1 feddan equals 4,200 m² or 0.42 ha), 93% of which are old dark lands of alluvial soils that have a texture which ranges from heavy clayey to clay. This area represents 71.6% of the total old alluvial land in Egypt (6 million feddan) and 55.5% of the total officially cultivated lands (8.6 million feddan). Salinity, water logging, and seawater intrusion in addition to pollution, nutrient depletion, and population encroachment are the most common predominant factors affecting the land degradation in the delta. There are only three main sources of hazardous salts in Nile Delta soils, irrigation water, shallow water table and water logging, and the seawater intrusion to the water table and surface soils. The Nile River and its irrigation canals work in the Nile valley as both irrigation and drainage canals at the same time, but the Nile Delta is covered with a good net of drainage canals that collect about 15 BCM a year that are reused in irrigation at a volume of 10 BCM. The drain in the delta area receives all kinds of pollutants such as sanitary and industrial wastes in addition to the residues of pesticides and nitrogen fertilizers used in cultivated soils. The reused drainage water becomes one of the main causes of land degradation and soil contamination in the delta region. Saline, saline-sodic, and sodic soils represent approximately 33% of the delta soils; the residual areas are in real threats due to the buildup of soil salinity. Urban sprawl is one of the main problems that threaten the limited highly fertile land in the Nile Delta. Land encroachment in the Nile Delta caused Egypt to lose about 740,000 feddan over the last 38 years.

Salt-affected soils in the Nile Delta are formed as a result of climate and inappropriate soil management (secondary is important here because there is initial or primary salinity referring to the effect of parent material, but the Egyptian parent material is the mud which comes by the Nile stream and leached through 1,800 km, the distance between Egypt and Ethiopia). Irrigation water, water logging, and saline water intrusion of the Mediterranean are the three sources of different types of salt-affected soils in the Nile Delta. Saline, saline-sodic, and sodic soils have strong presence in the delta land and represent an average of 37% of the total cultivated soils. The south delta is threatened by sodicity according to the low-salinity soils and highly carbonated irrigation water, while the north delta contains the highest area of saline and saline-sodic soils reaching 46%. Poor drainage in addition to reuse of more than 10 billion cubic meters of saline drainage water supports the buildup of salinity and sodicity. Gypsum amendment (CaSO₄·2H₂O) associated with intermittent leaching is the common method used in reclaiming salt-affected soils in Egypt. Furrow irrigation and rice cultivation under ponding are another two methods to adapt and mitigate salinity and sodicity buildup in the delta lands. The dominant salts in the delta are saline and sodic soils are sodium sulfate (NaSO₄) and sodium carbonate and bicarbonate (Na₂CO₃ and NaHCO₃). The solubility of these salts decreases sharply with temperature decreases; accordingly the reclamation and leaching processes should be applied during the summer warm season only. Improving drainage and preventing industrial and sanitary wastes in agricultural drain is a must.

Water scarcity is among one of the most major problems in many countries around the world. Egypt is one of the countries facing great challenges due to its limited water resources, represented mainly by its fixed share of water from the Nile River, and its general aridity. The scarcity of water resources in Egypt has triggered the need for using different types of low quality water. Agricultural Drainage Water (ADW) is considered as a strategic reserve for coping with increasing freshwater demands. Traditionally, the Egyptian Ministry of Water Resources and Irrigation (MWRI) has adopted different strategies aimed at increasing the use of ADW to confront the prevailing water scarcity. However, increasingly widespread pollution in the drainage system threatens these reuse strategies. Unfortunately, drainage networks in Egypt receive a large amount of untreated domestic and industrial wastewater. This chapter discusses the Egyptian water resources, and the ADW reuse activities in Egypt as a nonconventional water resource in Egypt.

Water resources play an important role in most human activities. During the last decades, water resources managers have faced severe challenges all over the world. As water becomes increasingly scarce in Egypt, the role of agriculture in the use of this essential resource has come under growing scrutiny especially because Egyptian agriculture consumes about 85% of Egypt’s limited water resources. On-farm water resources management plays a vital role in saving and optimizing water resources. The aim of this chapter is to review the irrigation development in the Nile Delta followed by an assessment of the on‐farm irrigation performance and economic aspects in irrigation management for the case study area, using a set of scenarios for improving the agricultural economic efficiency and sustainability of water use, while respecting cultural, hydrological, environmental, and institutional constrains on urban and environmental uses. The results indicate that, compared with the theoretical and actual polices of cultivation, an increase of the economic benefits and a decrease of the consumed water could be gained when using studied scenarios. Alternative cost-benefit scenarios for crop patterns are presented for decision-makers to improve national agricultural policies and to integrate the efforts of both government and farmers.

The Nile Delta is a dynamic ecosystem; its coastal area receives water from the two estuaries of the Nile River (Rosetta and Damietta), the outlets of the coastal lakes (Mariout, El-Manzala, El-Burullus, and Edku), and the drains. Water quality is a complex term that can indicate the state of the water compared to standard criteria for use in specific purposes. It contains many physical, chemical, and biological factors, but the critical water quality factors are water temperature, dissolved oxygen, nitrogen (ammonia/nitrate/nitrite), hydrogen ion concentration (pH), alkalinity, salinity and electrical conductivity, carbon dioxide, and turbidity. Estuaries are a mix between freshwater and marine water. Water and sediment quality were discussed for Rosetta and Damietta estuaries. Water quality of the Nile Delta coastal lakes is discussed for the four important lakes (Mariout, El-Manzala, El-Burullus, and Edku). Pollution, climate change, human activities, and fish farms are discussed as factors affecting water quality deterioration in the Nile River estuaries. The water quality index was introduced as single value representing water quality parameters. The spatial and temporal variations are presented in the Nile Delta estuaries. The pollution evaluation index is also discussed. Water management and environmental laws are briefly presented.

Shoreline change due to erosion and accretion is a major concern for integrated coastal zone management. The dynamic coastlines, such as the Nile Delta coast, pose considerable dangers regarding the coastal development. Accordingly, rapid techniques are required to update coastline maps of these areas and monitor rates of movement.

In this study, supervised classification and post-classification change detection techniques were applied to Landsat images acquired in 1984, 1990, 2005, and 2014, respectively, to detect changes in land cover and extract shoreline, hence identifying erosion and accretion areas around Rosetta promontory. This method provides a viable means for examining long-term shoreline changes. Four categories, including seawater, developed (agriculture and urban), sabkha (salt-flat), and undeveloped areas, were selected to evaluate their temporal changes by comparing the four selected images.

The shoreline was mapped by applying two different techniques: (1) a histogram threshold of Band 5 and (2) a combination of histogram threshold of Band 5 and two band ratios (Band 2/Band 4 and Band 2/Band 5). It was found that the developed area increased by 8.8% although the land in the study area has been contracted by 1.6% due to coastal erosion. The shoreline retreat rate has decreased more than 70% from 1984 to 2014. Nevertheless, it still suffers from significant erosion with a maximum rate of 37 m/year.

The global mean surface temperature is projected to increase about 1–3.5°C by the year 2100 caused by a sea-level rise (SLR) of about 15–95 cm. Low gradient coastal landforms most susceptible to inundation include deltas, estuaries, beaches and barrier islands, and coral reefs. Without serious adaptation measures, millions of peoples will be displaced from their homes. Moreover, the loss of productive land, they will have serious implications on job opportunities, food availability, and population movement. In this paper, the current status of many countries in the world affected by rising sea levels is presented. Also, the methods and strategies that can be used to cope with the expected sea level rising are discussed briefly such as nourishment, barriers, coastal armoring, managed retreat, application of the integrated coastal zone management (ICZM), use of floatable developments, etc. In addition, the different types of coastal dikes as widely used methods to protect the coasts from SLR are summarized. Finally, the current situation in Egypt and their vulnerability to SLR is presented.

Collecting and analyzing bathymetric information is essential to coastal and lake areas. This is commonly accomplished through field measurements, which are time consuming and costly. However, remotely sensed imagery provides wide coverage, low cost, and time-saving solutions for bathymetric measurements, especially in shallow areas with high erosion or sediment accumulation, such as onshore coastal areas. This chapter gives a brief description of the bathymetry determination, starting from the ordinary methods using echo sounders and sonars. Then the basics of detecting bathymetry from satellite images will be discussed followed by an illustration of the most common methods for image calibration. Also, the basic algorithms for bathymetry detection and the recently invented methods will be presented. Finally two case studies for bathymetry determination using satellite images will be discussed.

Change detection in the land use and land cover (LU and LC, respectively) is known as one of the most important indicators of global and regional environmental sustainability. Also, change detection in LULC is one of the most important and sound environmental management tools for sustainable development. In this paper, the maximum likelihood supervised classification is applied to subsets of the Landsat TM, ETM+, and OLI/TIRS images to monitor changes in the Burullus Lake and Manzala Lake. Burullus Lake is the second largest of the Egyptian northern lakes along the Mediterranean coast. Five classes are detected including seawater, lake water, sandbar and urban, floating vegetation, and agriculture. ERDAS IMAGINE and ArcGIS software are used in this study for processing of the images and managing the database of each image. The results show that the lake water area decreased by 38.01% (10,882.5 ha), while floating vegetation area increased mostly by the same amount during the period from 1990 to 2015. This increase in floating vegetation is due to the discharge of agricultural and municipal wastes in the lake without adequate treatment. The seawater has minor changes during the period of study. Other classes show remarkable changes over the time from 1990 to 2015. Manzala Lake is the largest natural lake in Egypt; it is located between longitudes 31°45′ and 32°22′E and latitudes 31°00′ and 31°35′N. Six classes are detected including seawater, lake water (water bodies), floating vegetation, islands, sandbar and urban, and agriculture. ERDAS IMAGINE and ArcGIS software are used in this study for processing of the images and managing the database of each image. The results show that the water bodies of the lake decreased by 57.06% (47,419.1 ha), while floating vegetation and island area increased mostly by the same amount during the period from 1984 to 2015. This increase in floating vegetation is due to the discharge of agricultural and municipal wastes in the lake without adequate treatment. The seawater has minor changes during the period of study. Other classes show remarkable changes over the time from 1984 to 2015. The future prediction was conducted using the annual rate of change over the next 15 years; the results from this prediction showed that the water bodies of the lake will be reduced by 84.67% (70,363.85 ha), and this decrease leads to a negative impact on fisheries and the environment. The results of this study shall help decision-makers to take the necessary measures to reduce the environmental risk and maintain the lake in order to sustain the lake water area against further reduction.

The fishery sector is considered one of the most significant sectors in the economic structure of Egypt. Therefore, this chapter aims to present an assessment of the current condition for the existing natural and artificial fishing ports that are located along the Nile Delta coast of Egypt.

The necessary data were collected via a well-designed questionnaire for the fishermen. The questionnaire contains two sections that cover some of the personal data of fishermen and fishing boats data. As well as four sections that discuss and measure the satisfaction of the fishermen for each of economical aspects, environmental issues, planning, facilities, and managerial aspects. A sample of 250 fishermen was the main targeted group for the questionnaire. The collected data were analyzed quantitatively and qualitatively.

The results confirmed that both fishing vessels and the investigated fishing ports are suffering from many issues in addition to the lack of management leading to various threats. The main common issues within the studied fishing ports were pollution, sedimentation, deterioration of infrastructure, lack of facilities for catching, and the traditional measures for management.

Based on the results, recommendations for further development of fishing ports are suggested to enable the proper expansion in the fishing industry and to move toward sustainable and green fishing ports. Another objective was to improve wastes disposal measures and initiate monitoring tools. Moreover, decision makers should provide infrastructure, facilities, and services to the ports to ensure higher fish productivity and a better fishing environment.

This chapter highlights the main conclusions and recommendations of the chapters presented in the book. Also, some findings from a few recently published research works related to the Nile Delta covered themes. Therefore, this chapter contains information on groundwater in the Nile Delta, land and soil, and drainage water, Nile Delta Coastal Zone assessment and management, and fishing ports, fish and fisheries. In addition, a set of recommendations for future research work is pointed out to direct the future research towards sustainability of the Nile Delta which is a main strategic theme of the Egyptian Government.