Human-induced sedimentological changes in Manzala Lagoon, Nile Delta, Egypt

 The Manzala Lagoon in Egypt's Nile Delta has become a sediment sink of reduced area and depth, with increased contaminant levels. Loss of much-needed fresh to brackish water reserves and decreased fish catches have serious ramifications. Herein, maps of temporal and regional sediment distributions in Manzala incorporate petrological and statistical analyses of 200 surficial and short core samples. These provide baseline information needed to help implement protection measures for this vital wetland. Four periods are considered: 1920s, 1940s, ∼1965, and 1990. Important depositional changes between 1940s and ∼1965 resulted from anthropogenic effects on this quasi-closed lagoon system, including industrial buildup, wetland conversion to agricultural land, and irrigation waterway development. Further modification from ∼1965 to 1990 is associated with closure of the Aswan High Dam, continued construction of waterways that discharge waste water into lagoon margins, and marine incursion into the northern lagoon. If current practices continue, the lagoon could be reduced to about one-third of its present area by 2050 AD. Received: 2 October 1997 · Accepted: 13 January 1998     

Comparison of DRASTIC and DC resistivity modeling for assessing aquifer vulnerability in the central Nile Delta,Egypt

DRASTIC indexing and integrated electrical conductivity (IEC) modeling are approaches for assessing aquifer vulnerability to surface pollution. DRASTIC indexing is more common, but IEC modeling is faster and more cost-effective because it requires less data and fewer processing steps. This study aimed to compare DRASTIC indexing with IEC modeling to determine whether the latter is sufficient on its own. Both approaches are utilized to determine zones vulnerable to groundwater pollution in the Nile Delta. Hence, assessing the nature and degree of risk are important for realizing effective measures toward damage minimization. For DRASTIC indexing, hydrogeological factors such as depth to aquifer, recharge rate, aquifer media, soil permeability, topography, impact of the vadose zone, and hydraulic conductivity were combined in a geographical information system environment for assessing the aquifer vulnerability. For IEC modeling, DC resistivity data were collected from 36 surface sounding points to cover the entire area and used to estimate the IEC index. Additionally, the vulnerable zones identified by both approaches were tested using a local-scale resistivity survey in the form of 1D and 2D resistivity imaging to determine the permeable pathways in the vadose zone. A correlation of 0.82 was obtained between the DRASTIC indexing and IEC modeling results. For additional benefit, the obtained DRASTIC and IEC models were used together to develop a vulnerability map. This map showed a very high vulnerability zone, a high-vulnerability zone, and moderate- and low-vulnerability zones constituting 19.89, 41, 27, and 12%, respectively, of the study area. Identifying where groundwater is more vulnerable to pollution enables more effective protection and management of groundwater resources in vulnerable areas.     

Assessment of land degradation east of the Nile Delta, Egypt using remote sensing and GIS techniques

Land degradation is one of the most common issues in the eastern part of the Nile Delta area that threatens the ongoing agricultural activities and prohibits further reclamation expansions. The different degradation types and the associated risk assessment of some soils types of western Suez Canal region during the period from 1997 to 2010 is discussed. The assessment of the different degradation degrees in the investigated area has been carried out through integrating remote sensing, GIS and GLASOD approaches. Results revealed that the salinization, alkalization, soil compaction and water logging are the main types of land degradation in the area. The main causative factors of human induced land degradation types are; over irrigation, human intervention in natural drainage, improper time use of heavy machinery and the absence of conservation measurements. Low and moderately clay flats, gypsifferous flats, have high to very high risk in both salinization sodication and physical degradation. Values such as EC, ESP, and ground water level reach 104.0 dS/m, 176? % and 60 cm, respectively. These results will be of great help and be basic sources for the planners and decision makers in sustainable planning. The spatial land degradation model was developed based on integration between remote sensing data, geographic information system, soil characteristics and DEM.     

The use of seismic interpretation for delineating the characteristic features of Messinian channels in the north Nile Delta, Egypt

Abu Madi Messinian Formation occupied a prominent issue as the most exploratory target in the search for natural gas in the Nile Delta. Interpretation of the available onshore seismic reflection data of the northeastern part of the Nile Delta reveals that there is a series of troughs, depressions, and mounded structures within the Abu Madi Formation (Messinian time). Onlap, downlap, and truncation relationship of reflections were observed very close to fault locations in the Miocene time. Many channels have been imaged clearly and described on the seismic reflection data of the onshore Nile Delta. The depths to these channels range between 2.5?s in the southeast to 3.1?s (t.w.t.) while their width ranges from 1?km to more than 5?km. These channels were formed by two factors: (1) submarine erosion and redeposition, during the relative sea level falls and (2) tectonic effect. Many of these channels followed more or less the trends of the historic branches of the ancient Nile Delta. The classification of these channels is based on some factors: (1) channel morphology (depth and width), (2) channel shape, and (3) tectonic effect.     

Post-Aswan dam sedimentation rate of lagoons of the Nile Delta,Egypt

This study uses radiometric analysis (²¹⁰Pb and ¹³⁷Cs) of short sediment cores with high-resolution sampling (1-cm interval) to trace sedimentation rates in the Nile Delta lagoons, particularly since completion of the Aswan High Dam in 1964. A declining trend in ²¹⁰Pb_ex as calculated by the CIC model is clearly identified in about 10 cm of the upper-core sediments from the lagoons of Manzala and Edku, accompanied by two spikes of ¹³⁷Cs in cores from the lagoons of Burullus and Edku. These findings illustrate average post-dam sedimentation rates ranging from 0.22 to 0.27 cm a⁻¹ in the lagoons, in contrast with those found previously based on low-resolution sampling. The lower sedimentation rates in the lagoons are a consequence of a dramatic reduction in riverine sediment load to the coastal area as a result of the damming. Although widespread erosion occurs along the open estuarine coast, the lagoon setting remains calmer than before due to coastal diking and freshwater regulation in the delta plain in the past decades. This provides the possibility of continuously preserved radiometric records in the less-bioturbated lagoon sediments. Dating individual layers using the CRS model has revealed increasing sedimentation rates in Manzala and Burullus since the 1980s, which can largely be explained as a consequence of the reduction in lagoon area due to intensifying reclamation. The post-dam sedimentation in the shrinking lagoons may have some adverse ecological consequences due to finer sediment’s affinity with pollutants. These findings would shed light on the environmental conservation and socioeconomic development in the Nile Delta region.     

Sea-level rise and shoreline retreat of the Nile Delta promontories, Egypt

Studies of the Nile Delta coast have indicated wide values of local subsidence, ranging from 0.4 to 5 mm/yr. Trend analysis of sea-level rise and shoreline retreat at two Nile Delta promontories have been studied. Records from tide gauges at Alexandria (1944–1989) and Port Said (1926–1987), north of the Nile delta coast, indicate a submergence of the land and/or a rise of the sea-level of 2 and 2.4 mm/yr, respectively.Dramatic erosion has occurred on some beaches of the Nile Delta. This is greatest at the tips of the Rosetta and Damietta promontories, with shoreline retreat up to 58 m/yr. Relationship between the shoreline retreat and sea level trends in terms of correlation analysis and application of the Bruun Rule indicates that the sea level rise has, by itself, a relatively minor effect on coastal erosion. The sea-level trend at the Nile delta coast is found to be only one of several effects on shoreline retreat. Major recent effects include a combination of cut-off of sediment supply to the coast by damming the River Nile and local hydrodynamic forces of waves and currents. Estimates of local future sea-level rise by the year 2100 at Alexandria and Port Said, respectively, is expected to be 37.9 and 44.2 cm. These expectations, combined with other factors, could accelerate coastal erosion, inundate wetlands and lowlands, and increase the salinity of lakes and aquifers.     

Sea-level rise and shoreline retreat of the Nile Delta promontories,Egypt

Studies of the Nile Delta coast have indicated wide values of local subsidence, ranging from 0.4 to 5 mm/yr. Trend analysis of sea-level rise and shoreline retreat at two Nile Delta promontories have been studied. Records from tide gauges at Alexandria (1944–1989) and Port Said (1926–1987), north of the Nile delta coast, indicate a submergence of the land and/or a rise of the sea-level of 2 and 2.4 mm/yr, respectively. Dramatic erosion has occurred on some beaches of the Nile Delta. This is greatest at the tips of the Rosetta and Damietta promontories, with shoreline retreat up to 58 m/yr. Relationship between the shoreline retreat and sea level trends in terms of correlation analysis and application of the Bruun Rule indicates that the sea level rise has, by itself, a relatively minor effect on coastal erosion. The sea-level trend at the Nile delta coast is found to be only one of several effects on shoreline retreat. Major recent effects include a combination of cut-off of sediment supply to the coast by damming the River Nile and local hydrodynamic forces of waves and currents. Estimates of local future sea-level rise by the year 2100 at Alexandria and Port Said, respectively, is expected to be 37.9 and 44.2 cm. These expectations, combined with other factors, could accelerate coastal erosion, inundate wetlands and lowlands, and increase the salinity of lakes and aquifers.     

Hydro-environmental status and soil management of the River Nile Delta,Egypt

The sea level rise has its own-bearing on the coastal recession and hydro-environmental degradation of the River Nile Delta. Attempts are made here to use remote sensing to detect the coastal recession in some selected parts and delineating the chemistry of groundwater aquifers and surface water, which lie along south-mid-northern and coastal zone of the Nile Delta. Eight water samples from groundwater monitoring wells and 13 water samples from surface water were collected and analyzed for various hydrochemical parameters. The groundwater samples are classified into five hydrochemical facies on Hill-Piper trilinear diagram based on the dominance of different cations and anions: facies 1: Ca–Mg–Na–HCO₃–Cl–SO₄ type I; facies 2: Na–Cl–HCO₃ type II; facies 3: Na–Ca–Mg–Cl type III, facies 4: Ca–Na–Mg–Cl–HCO₃ type IV and facies 5: Na–Mg–Cl type V. The hydrochemical facies showed that the majority of samples were enriched in sodium, bicarbonate and chloride types and, which reflected that the sea water and tidal channel play a major role in controlling the groundwater chemical composition in the Quaternary shallow aquifers, with a severe degradation going north of Nile Delta. Also, the relationship between the dissolved chloride (Cl, mmol/l), as a variable, and other major ion combinations (in mmol/l) were considered as another criterion for chemical classification system. The low and medium chloride groundwater occurs in southern and mid Nile Delta (Classes A and B), whereas the high and very high chloride (classes D and C) almost covers the northern parts of the Nile Delta indicating the severe effect of sea water intrusion. Other facets of hydro-environmental degradation are reflected through monitoring the soil degradation process within the last two decades in the northern part of Nile Delta. Land degradation was assessed by adopting new approach through the integration of GLASOD/FAO approach and Remote Sensing/GIS techniques. The main types of human induced soil degradation observed in the studied area are salinity, alkalinity (sodicity), compaction and water logging. On the other hand, water erosion because of sea rise is assessed. Multi-dates satellite data from Landsat TM and ETM+ images dated 1983 and 2003 were used to detect the changes of shoreline during the last two decades. The obtained results showed that, the eroded areas were determined as 568.20 acre; meanwhile the accreted areas were detected as 494.61 acre during the 20-year period.     

Sustainable multivariate analysis for land use management in El-Sharkiya,Egypt

In Egypt, major sustainability variables could be identified as scarce of soil and water resources, environmental degradation, rapid population growth, institutional arrangement that includes land tenure and farm fragmentation, agricultural administration, lack of infrastructure, and credit utilization. The main objective of the current work is to evaluate the sustainable land use management (SLM) model through biophysics and socioeconomic elements for the purpose of combating sustainability constraints that preclude the agricultural development geospatially. In this research, from the geomorphologic point of view, the obtained results showed three main landscapes. They were identified in the study area as: fluviolacustrine plain, Aeolian deposits, and flood plain. The study area was dominated by some physical and chemical degradation processes with different scales breaking down the equilibrium of soil stability. The SLM model was implemented and assessed from multivariate perspective points of productivity, security, protection, economic viability, and social acceptability. Four SLM classes were outlined as follows: class I, land management practices that did meet sustainability requirements with a score ≥0.65, which represented 31.0 % of the considered agricultural study area; class II, land management practices that were marginally above the sustainability threshold and represented 12.6 %; class III, land management practices that were slightly below the threshold of sustainability and represented 8.60 %; class IV, land management practices that did not meet sustainability requirements with index values >0.1 that represented 47.86 %. As a general conclusion, it is found that land management practices tend to be unsustainable in the area under investigation for certain constraints that play motivated roles in lowering the targeted land sustainability.     

U-Pb (zircon) ages for the gneissic terrane west of the Nile,southern Egypt

The first U-Pb zircon ages are reported for the gneissic bedrock inliers previously interpreted as part of the Nile Craton. The inliers crop out in the Egyptian Western Desert, east of the Uweinat area and west of the Eastern Desert. Multi- and single-grain zircon analyses of granitoid gneiss and migmatite from Gebel Um Shagir, Aswan, and another locality approximately 160 km south-west of Aswan, yield simple discordia with near modern day Pb loss trajectories, and the following Neoproterozoic crystallization ages: 626+4/–3, 634 ± 4 and 741 ± 3 Ma. In contrast, multi- and single-grain U-Pb analyses (zircon and sphene) from an anorthositic gabbro at Gebel Kamil (22°46N 26°21E) and an anorthosite at Gebel El Asr (22°46N 31°10E) yield Archean and Paleoproterozoic emplacement ages. The former yield a crystallization age of > 2.67 Ga and a metamorphic age of 2.0 Ga; the latter a metamorphic age of 0.69 Ga and an inheritance age of 1.9–2.1 Ga. Because high grade gneiss and migmatite of Neoproterozoic, Paleoproterozoic and Archean age crop out west of the Nile, pre-Neoproterozoic crust should no longer be identified by its metamorphic grade. By contrast, mapping the anorthosite and related rocks might provide first-order estimates for the extension of pre-Neoproterozoic crust in north-east Africa. It is suggested that Archean and Paleoproterozoic crust of the Uweinat and Congo Craton are contiguous because these U-Pb (zircon) data show no evidence for a Neoproterozoic thermal overprint in the Gebel Kamil area and there is no pronounced Neoproterozoic magmatic activity south of the Uweinat inlier and north of the Congo Craton.     

The Quality Control of Engineering Properties for Stabilizing Silty Nile Delta Clay Soil,Egypt

Clay soil with low-bearing capacities can present great problems underlying pavement and light structures due to uncertainty associated with their performance. This paper describes a sonic based testing methodology for quality control of a surface stabilized soil. From an engineering aspect, an increase in water content has a number of disadvantageous consequences: cohesion decreases, the soil swells, the alternating dry-out/shrinkage and wetting/swelling effects destroy the rock or a soil structure. Cement is mixed into the soil to increase both the strength and the usability of local soils in constructions purposes. This is to overcome the problems by strengthening the soil underlying the structure or diminishing the leads transmitted from the foundation to the soil. The compressive strength of the stabilized soil is highly dependent on the type of soil, moisture content, cement content, and compaction work, and can therefore vary significantly in the field. The authors performed the quality control by measuring the sonic and tensile strength velocity in the stabilized soil that has been correlated to compressive strength in native materials. The improvement of the soil materials by the addition of cement could make the material suitable as filling materials, foundation and/or a road base construction. The quality control for the stabilized soils was investigated using sonic measurements and strength gain. The test methods were performed to evaluate the degree of improvement achieved through the measurement of compression and shear-wave velocities of the soil under study. Scanning electron microscopy and electron dispersive X-ray analyses were performed on raw and laboratory treated for qualitative understanding the strength minerals formed during stabilization. The sonic test showed a considerable improvement with curing time and percentages of stabilizer. Mineralogical studies indicated the formation of silica and alumina hydrates along with interwoven structure of cement treated clay particles suggesting adequate mixing of the soil and binder owing to the strength of the soil materials.     

Land suitability analysis for maize production in Indonesia using satellite remote sensing and GIS-based multicriteria decision support system

GeoJournal - Maize is one of the potential crops can help in regional food production with self-sufficiency of foods in the drought prone areas of East Java in Indonesia. The purpose of this...     

Chemical Fractionation of Aluminium in the Sediments of El-Burullus Lagoon of Nile Delta,Egypt

A five step sequential extraction technique, following Tessier’s protocol has been applied to determine the chemical association of aluminium with major sedimentary phases (exchangeable, carbonate, manganese and iron oxides, organic and residual fraction) in four short sediment cores collected from El-Burullus lagoon of the Nile delta, Egypt. This study is a first approach of chemical fractionation of aluminium in one of the protective areas of the Mediterranean Sea of Egypt. The total metal content was also determined. The results of the fractionation study indicated that aluminium was mainly associated with the residual fraction (>95%). The organic and Fe–Mn oxide fractions were the next important phases. The exchangeable and carbonate fractions were less than 1%, limiting its potential toxicity as a pollutant. The geochemical analysis of aluminium forms reflected the lithogenic origin of this metal in the study area.     

Below the radar: the boom of groundwater use in the central part of the Nile Delta in Egypt

The Nile Delta of Egypt is known for its large irrigated area supplied with water diverted from the Nile River, with a limited use of groundwater, largely for domestic and industrial use. Official statistics for the whole delta indicate that there are a few thousand individual wells used for agriculture by a population of over 2 million farmers. This study, however, shows that a phenomenon of groundwater development for irrigation has been unfolding over the last few years, largely below the radar of managers and researchers. A survey was carried out in the central part of the delta with the objective of (1) uncovering the actual situation of groundwater use in this part of the delta and (2) speculating on its implications. The results of the survey pointed to a recent and booming tube-well drilling industry, with well densities in some parts reaching one well every 2 ha. The development of groundwater abstraction in the central delta is strongly linked to inadequate and/or untimely availability of surface water in the canals. A technical, economic, and management characterization of wells complements the study, showing a continuum between purely private/individual ownership of wells and collective investments and management. Lastly, the article explores the implications of unchecked abstraction at the farm, local and delta scales.     

Petrophysical characteristics of Wakar Formation, Port Fouad marine field, north Nile Delta, Egypt

Petrophysical characteristics of the late Miocene Wakar Formation of Port Fouad Marine Field have been evaluated through the analysis of well-logging records of nine exploratory and development wells, distributed in the northeastern offshore area of the Nile Delta. These records have been analyzed through utilizing the ELAN Plus petrophysics software in order to identify the lithological constituents and fluid saturation parameters. The gas potentialities of the studied formation have been evaluated through number of isoparameteric maps. The litho-saturation analysis indicates that the Wakar Formation in the studied wells is mainly gas-bearing with some water-bearing sand levels. The analytical formation evaluation reveals that the lithological facies consists mainly of sandstone, shale, and siltstone. The disseminated shale is mainly of dispersed type and some of laminated habitat. It also points to the dominance of the intergranular porosity. The isoparametric maps of the petrophysical parameters show that the level S1 of Wakar Formation is the main reservoir.     

Geophysical and hydrological investigations at the west bank of Nile River (Luxor, Egypt)

Luxor, the modern Egyptian city that occupies the site of ancient Thebes, is famed for its magnificent ancient monuments. Since 1967, the Aswan high dam has prevented the annual flooding of the Nile River, resulting in excessive salt accumulation on the Nile floodplains and on exposed monument surfaces. In addition, the expansion of agricultural land within the Luxor study area has resulted in increased salinity and groundwater level. These conditions accelerate the degradation of buried and exposed monuments that were fairly well preserved in the past. To mitigate this problem, it is necessary to first understand the near-surface setting and the groundwater conditions of the Luxor area. A geophysical investigation was carried out using resistivity and electromagnetic surveys. In addition, a chemical analysis was conducted of some surface water samples collected from canals and the sacred lake of Memnon Temple. Based on the results of the geophysical surveys and the chemical analysis of the water samples, the shallow subsurface was characterized into four geoelecterical units. Groundwater flow directions were determined to be from the central area to the west, causing a rise in the groundwater levels and groundwater salinity in the area of monuments.     

Vulnerability and fate of a coastal sand dune complex,Rosetta-Idku,northwestern Nile Delta,Egypt

Types, distribution, and origin of recent sand dunes between Rosetta and Idku, in the western sector of the Nile Delta, Egypt were investigated. Sand samples from the dunes, beach, and seafloor were studied for grain size distribution and mineralogical composition. It has been found that most of the dunes in the study area have been subjected to deterioration and removal due to the construction of buildings and the International Coastal Highway. The remnant constitutes a damaged belt of foredunes that extends from El Bouseily village to the west of Idku town. The dune’s origin is interpreted to be the result of coastal drifting and the subsequent transport of sediments of the former Canopic Nile branch eastward by the predominant longshore current and by aeolian processes. The blown sand grains accumulated to form a belt of coastal sand dunes of original longitudinal and crescentic forms. Urbanization of the coast has severely altered the landscape. The study area is considered vulnerable to the impacts of climate change and the expected rise in sea level. The outcome of potential sea level rise is serious; erosion problems are expected to be exacerbated and vast areas from land and property would be lost. Thus, protection and preservation the remaining dunes in the study area are vital requirements for shore protection.     

Climate change and its impacts on the coastal zone of the Nile Delta,Egypt

The main objectives of the current work are (1) to determine historic pattern of shoreline changes (erosion and accretion) along the north coast of the Nile Delta, (2) to present a future view on what to be expected regarding climate change impacts, sea-level rise (SLR) scenarios, expected land losses and alteration of some soil characteristics (3) to recognize negative impacts of SLR on the Nile Delta coast and (4) to assess and suggest protection measures. The current investigation was conducted using the advanced techniques of remote sensing and geographic information system. The investigated area with 394 measured locations is located along the northern coast of the Nile Delta between Alexandria and ElTina plain in Sinai peninsula exactly between 29°20′ and 32°40′ E and 29°54′ and 31°35′ N with the minimum erosion values of 1.11 m², maximum of 6,044,951.64 m² and total of 16.02 km². On the other hand, 177 sites showed minimum accretion values of 0.05 m², maximum of 2,876,855.86 m² and total of 13.19 km². SLR was determined by applying the quadrant equation for 10-year intervals using 1990 as the base year. Mediterranean SLR along the Nile Delta coast could be estimated considering three different scenarios (low 0.20 m, medium 0.50 m, and high 0.90 m). Impacts of SLR are divided into (1) primary and (2) secondary impacts. Over the coming decades, the Nile Delta will face greater threat due to SLR and land subsidence as well. Regarding climate change and its impacts on soil characteristics, rapid increase in salinity values during the former three decades were found. This increase may be due to the intrusion of salty water of the Mediterranean. On the other hand, organic matter content decreased due to higher temperature, especially during the summer season. Some protection measures were assessed and suggested to combat or tackle SLR.     

Using GIS modeling to assess the agricultural sustainability in Kafr El-Sheikh governorate, Nile Delta, Egypt

The evaluation of agricultural sustainability status helps in identifying specific indicators that constrain the achievement of sustainable agriculture. The agricultural sector in Egypt is facing major sustainability constraints such as scarce land and water resources, environmental degradation, and rapid population growth as well as institutional arrangement including land tenure and farm fragmentation, agricultural administration, lack of infrastructure, and credit utilization and high interest rates. This study aims to evaluate the agricultural sustainability in some areas in Kafr El-Sheikh governorate, north of the Nile Delta; the international framework for evaluating sustainable land management was used for realizing this objective. The map of the physiographic soils of the studied area was produced depending upon Landsat ETM⁺ images analysis; the results indicate that the area includes three main landscapes, i.e., alluvial, lacustrine, and marine plains. The characteristics of productivity, security, protection, economic viability, and social acceptability in the different mapping units were assessed. The obtained results show that the studied area includes two different class types, the first are the lands that are marginally below the requirement of sustainability and the second are those lands that do not meet sustainability requirements. The former class is represented by the physiographic units of alluvial plain, whereas the latter class is represented by the physiographic units of the lacustrine and marine plains. The sustainability constrains in the studied area are related to the soil productivity, economic viability, and social acceptability.