Insight into land cover dynamics and water challenges under anthropogenic and climatic changes in the eastern Nile Delta: Inference from remote sensing and GIS data

The destabilization of delta's worldwide due to climate change and human activities presents challenges in meeting the growing demands for freshwater and food. The Nile Delta in Egypt is a prime example of a vulnerable region facing various stressors. In order to preserve land and water resources, it is crucial to monitor the spatial and temporal changes in Land Use/Land Cover (LULC), shoreline, and Terrestrial Water Storage (TWS) in these vulnerable regions This study comprehensively investigates the dynamic changes in LULC and their associated water and soil responses in the Eastern Nile Delta under these combined impacts. To achieve this goal, a combination of remote sensing techniques utilizing Landsat (5, 8, and 9), and GRACE datasets, along with field observations and Geographic Information System (GIS) tools, was employed. Accordingly, shoreline changes show coastal erosion rates ranging from 5.28 to 34.92 m/year due to climate change-induced SLR, with continued inland movement predicted for the next 20 years. Moreover, the dynamic changes in urbanization and alterations in agricultural cover have considerable penalties for water demand. Analysis of GRACE data indicates a notable reduction in average TWS by 77.89 mm between 2002 and 2017, with an annual rate, estimated at -5.821 mm/year. Soil sampling in highly vulnerable areas confirms agricultural degradation attributed to elevated salinity levels, with EC values ranging from 3.60 to 190 ds/m. These finds provide valuable insights for stakeholders and policymakers, to make reliable strategies regarding water allocation, land use regulations, and climate change adaptation in the worldwide vulnerable deltas.

Integrated geochemical and magnetic potentially toxic elements assessment: a statistical solution discriminating anthropogenic and lithogenic magnetic signals in a complex area of the southeast Nile Delta

Magnetic proxy approaches proved to be efficient for potentially toxic elements (PTEs) pollution assessment when targeting forests or areas with a homogenous background where anthropogenic magnetic signals could be easily distinguished. Here, we present a multidisciplinary approach for magnetic susceptibility ([Formula: see text]) and HM assessment in a complex area in the Nile Delta, where geogenic input, land use, and various industries with different fly ash and surface water emissions interfere. Statistical analysis discriminates between the effects of lithologic elements and the concentrations of toxic anthropogenic elements. The studied elements are classified into lithogenic and anthropogenic-related (HMs, Au industry, and fertilizers industry) groups with maximum contamination levels of eight anthropogenic-related and highly toxic PTEs (Cu, Zn, Mo, Cd, Sb, Pb, Hg, and As) in the Akrasha industrial area (pollution load index = 15.84). Considering the whole data set, the numerical correlation of [Formula: see text] with most PTE concentrations and the pollution load index (PLI) is weak, while it is moderate to strong with lithogenic elements. However, a comparison of lithogenic elements and PTE concentrations along with x-values in two separate clusters supports the correspondence of lithology with elevated x-values in silt and clay-rich soil samples as well as HM concentration in industrial sandy soils. Correspondence between magnetic maps and chemistry data with land use reflects the potential of magnetic proxy methods for qualitative PTE pollution pre-delineation of the polluted spots, provided that lithological conditions are carefully considered.

Community structure, seasonal dynamics, and impact of some biological parameters of the African catfish Clarias gariepinus on the infection level of the helminth parasites

Fish parasitic diseases impose a major economic concern on aquaculture. Identified parasites of Clarias gariepinus include one monogenean, Macrogyrodactylus clarii (gills), three digeneans Orientocreadium batrachoides, Eumasenia bangweulensis and Sanguinicola sp. (intestine), two cestodes Tetracampose ciliotheca and Monobothrioides chalmersius (intestine) and two nematodes Paracamallanus cyathopharynx and Procamallanus pseudolaeviconchus (intestine and stomach). Most nematodes, digeneans and cestodes occurred in all months of the study period. However, M. clarii and Sanguinicola sp. disappeared for 6 and 8 months of the year, respectively. The digenean group was the most dominant followed by the cestode and nematode groups, respectively. The nematodes attained the highest infection rate over the digeneans and cestodes while the monogenean M. clarii recorded the lowest infection rate. The infection level of examined parasites varied seasonally, but no overall significant pattern was detected. E. bangweulensis showed a highly significant difference for all parameters seasonally. A higher prevalence was obvious in males than females for most parasites, and the opposite for the mean intensity except for P. pseudolaeviconchus which was significantly different between females and males in the mean abundance. There were variations in the relationship between the host condition factor and helminth parasite infection levels. O. batrachoides, E. bangweulensis and P. cyathopharynx recorded the highest infection level in class II. The mean prevalence was highly significantly different between host classes for T. ciliotheca, M. chalmersius and P. pseudolaeviconchus.

Landfill site selection using MCDM methods and GIS in the central part of the Nile Delta, Egypt

One of the most prevalent and serious issues afflicting developing countries is the lack of adequate space for waste disposal. Al-Gharbia Governorate, located in the middle of the Nile Delta in Egypt, suffers from random selection of sites for solid waste disposal, resulting in significant environmental challenges. The aim of this study is to determine optimal landfill locations within Al-Gharbia Governorate and validate the existing landfill sites. Four techniques of multi-criteria decision-making (MCDM) were applied to generate suitability maps for the Governorate: the analytical hierarchy procedure (AHP), ratio scale weighting (RSW), straight rank sum (SRS), and Boolean method. Eleven effective criteria were considered: groundwater, surface water, elevation, slope, soils, land use, roads, railways, urban areas, villages, and power lines. The suitability maps were categorized into four different classes: suitable, moderately suitable, low suitable, and unsuitable. The latest suitability map was determined by combining the results from the different methods, providing decision-makers with the means to select the optimal landfill site. The suitable zone encompasses a small area (3%), predominantly located in the northeast region (Al-Mahalla), central region (Tanta), and northern region (Kotour). Conversely, the unsuitable area covers a substantial portion (72.7%) due to the agricultural nature of the governorate, high population density, and elevated groundwater levels. Furthermore, all existing landfill sites fall within unsuitable or low suitable areas, inflicting severe impacts on the nearby environment, public health, and groundwater integrity.

Historical changes in fish landings indicate a significant shift in fish catch composition and biodiversity loss in the Nile-Delta lakes

To monitor the changes in fish biodiversity and to elucidate the factors responsible for these changes, the landings composition (LC) over the past 30 years in the Nile-Delta lakes was quantitatively analyzed. The LC data indicates a shift in target species towards demersal opportunistic species. A significant difference (P < 0.001) between two main intervals highlighted in both PERMANOVA and PCA plot; the first interval (1991-2002) is dominated by Tilapia and rare species, while the second interval (2003-2020) is dominated by the opportunistic catfish and mullet species. Noticeable declines in species richness and landings of rare species were observed, where rare taxa either have been overexploited or they may be positively affected by increasing pollution levels than do other dominated species such as Tilapia. In contrast, opportunistic fish species such as catfish and mullet, have flourished in such polluted water due to their ability to tolerate seasonal pollution-related hypoxia.

n-Alkanes and PAHs baseline distributions and sources in the sediments of the Nile Delta coast of the southeastern Mediterranean

The variations in the levels of n-alkanes and Polycyclic Aromatic Hydrocarbons (PAHs) in the sediment of the Nile Delta coast and extended to Bardaweel Lagoon along the Mediterranean were investigated during September 2021. The total n-alkane concentrations in the sediment samples ranged from 18.85 to 164.37 μg/g with an average value of 51.98 ± 17.49 μg/g. Similarly, the ΣPAHs concentrations ranged between 4.55 and 207.48 ng/g with an average of 27.89 ± 49.82 ng/g. The carbon preference index (CPI) values were in the 0.21 to 1.39 range, indicating variations in the sources of n-alkane at the analyzed locations. The mean carbon number (MCN) values ranged from 7.41 to 15.47, with an average of 13.34 ± 1.69. The levels of both low and high molecular weight PAHs were lower than the median and low effective range values (ERM and ERL). The computed total TEQ value varied from 0.102 to 4.129 ng/g in the sediment samples under investigation.

Coxiella burnetii and its risk factors in cattle in Egypt: a seroepidemiological survey

Animal production is greatly affected by Q fever. As a result of a lack of methodology and financial means to perform extensive epidemiological surveys, the disease's underdiagnosis has proven to be a challenge for effective control. The present study aimed to determine the seroprevalence of C. burnetii in cattle raising in four governorates situated at Nile Delta of Egypt and assess the associated risk factors for infection. A total of 480 serum samples were collected from cattle and examined for presence of anti-C. burnetii antibodies using indirect ELISA assay. The overall seroprevalence of C. burnetii among examined cattle was 19.8%, with the Qalyubia governorate having the highest prevalence. The results of multivariable logistic regression analysis revealed significant association between C. burnetii seropositivity and age, communal grazing and/or watering, contact with small ruminants and history of infertility. According to the findings of this work, C. burnetii is circulating among cattle living in Nile Delta. It is suggested that adequate hygiene procedures and biosecurity measures should be implemented to limit the transmission of pathogens within cow herds and potential human exposure.

Monitoring of oil spill in the offshore zone of the Nile Delta using Sentinel data

This study aims to monitor and map the oil spills which occurred from 2019 to 2021 along the northeastern portion of the Nile Delta using Sentinel-1 (SAR) and Sentinel-2 (MSI) data. The examination of VV polarized SAR-C images displayed the presence of the oil spills as dark spots of different sizes. These images were processed using the oil spills detection model in SNAP Toolbox. The oceanographic parameters that may influence the dispersal of oil spills were mapped using GIS technique. This study identified 29 oil spills during the study period in the research area. The largest spill was detected on February 23, 2019, and covered an area of about 10.5 km². The band ratios and decorrelation stretch methods of available Sentinel-2 data confirmed the results of SAR-C data. The accuracy assessment of spills was achieved using Parallelepiped supervised classification model. The results demonstrated that the overall accuracy (OA) and Kappa coefficient (KC) for seawater, land, and oil spills classes were between 86% and 98% and 0.73% and 0.97%, respectively. The sensitivity zone of oil spills was higher in winter than in summer. This study proved the efficiency of VV polarized data of Sentinel-1 sensor for detection and mapping of oil spills. Several management strategies are needed in the offshore zone of the Nile Delta to limit oil pollution effects on the marine environment.

Screening and Identification of Indigenous Entomopathogenic Fungal Isolates from Agricultural Farmland Soils in Nile Delta, Egypt

The compound negative impact of insect pests attacking agricultural ecosystems includes (i) direct yield losses from damaged crops, (ii) the economic cost of the attempt to prevent these losses and (iii) the negative short- and long-term hazard effects of chemical pesticides on human and environmental health. Entomopathogenic fungi (EMPF) are a group of microorganisms that represent the natural enemies of a number of crop pests, presenting an opportunity to harness their evolutionary fine-tuned relationship with their insect hosts as biocontrol agents in integrated pest management programs. The aim of this study was to establish an indigenous EMPF collection via the Galleria mellonella (greater wax moth) entrapment method from the soils of Nile Delta, Egypt. Obtained insect associated fungal isolates were bio-assayed for pathogenicity against the serious pest Spodoptera litura and Tenebrio molitor, and the seven outperforming isolates were selected for molecular identification and thermotolerance assay. Based on ITS sequence analysis and phylogeny, selected isolates were identified as Beauveria bassiana (four isolates), Metarhizium anisopliae (two isolates) and one isolate of Cordyceps javanica. The obtained results demonstrated (i) the efficacy of using insect baiting coupled with molecular identification and pathogenicity screening to isolate EMPF to control insect pests, and (ii) the availability of indigenous virulent EMPF in Nile Delta's soil, which can be exploited for the development of sustainable crop protection strategies.

Seroprevalence and epidemiological characteristics of HDV infection among HBV patients in the Nile Delta, Egypt

The epidemiology of HDV infection worldwide is obscure. Mapping the epidemiology of the infection is highly required, so, we aimed to estimate the prevalence of hepatitis D virus infection among chronic hepatitis B patients and the epidemiological characteristics in the Nile delta in Egypt. This was a prospective observational cross-sectional study including consecutive chronic hepatitis B patients in the out-patient clinics at the Egyptian Liver Research Institute and Hospital (ELRIAH) and its satellites in the Nile Delta from January 2016 until August 2018. They were recruited from patients enrolled in Educate, Test and Treat program, which was implemented in 73 Egyptian Villages. Subjects were tested by using HBsAg serological rapid diagnostic tests (RDTs), and then HBV DNA by PCR was done in HBsAg-positive cases. HDV IgG antibody testing and confirmatory HDV RNA PCR were done. Complete liver functions, abdominal ultrasonography and FibroScan were also performed. The prevalence of HDV was 3.4% using anti-delta antibody (22/631), and only 8 were positive for HDV RNA (8/22, 36.4%). Overall HDV prevalence using PCR was 8/631(1.27%). HDV-positive cases were mainly males (68.2%). Eight cases were cirrhotic (36.4%), 3 (13.6%) had HCC and 7 (31.8%) were HBeAg positive. HDV prevalence is low among chronic hepatitis B patients in the Nile delta, Egypt. Screening for HDV IgG is recommended in CHB patients who had cirrhosis, HCC or HBeAg positive.

Classification and identification of different minerals in the Mediterranean sediments using PSA, FTIR, and XRD techniques

While the Mediterranean coastal region of the Nile Delta is critical socioeconomically, it is under significant environmental stress due to the growing load from diverse land-based activities. This study examines the fluctuations in the concentrations of several minerals in sediments from depths ranging from 10 to 50 m. This study is considering the first work that carries the identification of different minerals by using two different techniques: Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction technique (XRD), in this area. At the same time, the particle size was also assessed. The particle size analyzer (PSA) results showed that the grain size analyses in the sediments varied between slightly gravelly sand, slightly gravelly mud, and silty sand. Mineral identification using FTIR and XRD analysis proved that some minerals such as aragonite, calcite, quartz, kaolinite, montmorillonite, albite, muscovite, and microcline have been presented in most of the studied locations.

Very High Fascioliasis Intensities in Schoolchildren from Nile Delta Governorates, Egypt: The Old World Highest Burdens Found in Lowlands

Quantitative coprological analyses of children were performed in Alexandria and Behera governorates, Egypt, to ascertain whether individual intensities in the Nile Delta lowlands reach high levels as those known in hyperendemic highland areas of Latin America. Analyses focused on subjects presenting intensities higher than 400 eggs per gram of faeces (epg), the high burden cut-off according to WHO classification. A total of 96 children were found to shed between 408 and 2304 epg, with arithmetic and geometric means of 699.5 and 629.07 epg, respectively. Intensities found are the highest hitherto recorded in Egypt, and also in the whole Old World. A total of 38 (39.6%) were males and 58 (60.4%) were females, with high intensities according to gender following a negative binomial distribution. The high burden distribution shows a peak in the 7-10 year-old children group, more precocious in females than males. Results showed high burdens in winter to be remarkably higher than those known in summer. The fascioliasis scenario in Egyptian lowlands shows similarities to highlands of Bolivia and Peru. Diagnostic methods, pathogenicity and morbidity in high burdens should be considered. The need for an appropriate quantitative assessment of heavy infected children to avoid post-treatment colic episodes is highlighted.

A comprehensive management model to maximize the benefits of agriculture drainage water reuse

Water scarcity in Egypt is an escalating challenge due to the ever-increasing water demands and limited resources. Economically, agricultural drainage water reuse (ADWR) in irrigation is an essential option to cope with freshwater shortage. However, it requires environmentally sound management to minimize possible risks on irrigated soils and human health. Consequently, this research aims at assessing and managing the reuse process by developing a statistically based quality control model capable to investigate the observed and expected capability of the process. Additionally, complementary corrective actions and the decision models were proposed when the reuse processes operate in violation of the standards. These models were tested and validated using data collected from the year 2015 to 2019 at the Delengat pump station in the Western Nile Delta region, which mixes the Delengat drain water with the El-Hager irrigation canal. After raising the awareness amongst the farmers and providing them adequate sanitation services, it was inferred that the ADWR process could provide safe drainage water to be mixed with fresh water. Based on the performed simulations, both models proved to be systematic, quantitative, suitable for computers, and helpful in making informed decisions concerning the sustainability of the reuse process under future water uncertainty. PRACTITIONER POINTS: ▪In Egypt, drainage water reuse is an essential option to cope freshwater shortage. ▪A statistically based quality control model was developed to investigate the capability of the agriculture drainage water reuse process. ▪Additionally, complementary corrective actions and decision models were proposed when the reuse processes operate in violation of the standards. ▪Both the models proved helpful in making informed decisions concerning the sustainability of the reuse process under the future water uncertainty.

Uptake prediction of nine heavy metals by Eichhornia crassipes grown in irrigation canals: A biomonitoring approach

The principal objective of this study is to generate mathematical regression equations that facilitate the estimation of the extent to which Eichhornia crassipes (C. Mart.) Solms, water hyacinth, absorbs heavy metals (HMs) into four plant organs (laminae, petioles, roots, and stolons). This study considers the absorption of nine HMs (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), and the E. crassipes evaluated in this study were located in three irrigation canals in the North Nile Delta in Egypt, with sampling being conducted in both monospecific and homogenous E. crassipes. Samples of both E. crassipes and water were collected on a monthly basis during one growing season. Analysis of the water samples showed that the HM concentrations ranged from 1.1 μg/l for Cd to 2079.8 μg/l for Fe. All HMs were more concentrated in the E. crassipes roots than in any other organ. Typically, there was a significant correlation between the HM levels in the water and the HM levels in the E. crassipes organs. E. crassipes was documented by a bioconcentration factor > 1.0 for all HMs. The translocation factor in this study was <1.0 for all HMs. The t-values that referred to the discrepancies between the measured and predicted values of the HMs in the four E. crassipes organs were not significant. This finding can be considered to be an indication of the goodness of fit with respect to the ability of the equations to forecast HM uptake. Therefore, the developed equations will benefit the prediction of HM uptake by E. crassipes grown in irrigation canals in the Nile Delta. The efficacy of E. crassipes as a metric for gauging the aggregate impact of environmental pollution in water sources and its potential application in biomonitoring are confirmed in this study.

Forecasting shoreline changes along the Egyptian Nile Delta coast using Landsat image series and Geographic Information System

Before construction of the Aswan High Dam, the Nile Delta was expanding and advancing into the Mediterranean Sea. Subsequently, it became a highly destructive Delta due to the lack of sediment discharge, climate change, subsidence, and coastal processes (e.g. wind, waves, tides, and littoral currents). Many coastal structures have been erected to stop or mitigate coastal problems in the study area. We used 31 Landsat images to monitor the fluctuation of erosion and deposition along the study area. The shorelines in these huge datasets were extracted using standard techniques. Linear regression ratio (LRR) and end-point rate (EPR) were used with Digital Shoreline Analysis System (DSAS) software to determine the rates of beach changes; we then forecast future shoreline changes. The accuracy of the model's results was checked using the ground field measurements of several studies. This model also creates an estimate of the position uncertainty at each time step. The value of the uncertainty is low (approximately half a pixel) along the shorelines without coastal protection. This study aimed to forecast future beach evolution to the year 2041 to evaluate its sensibility and facilitate proposals for coastal protection for human safety and habitats if the coastal processes and climate change continue to worsen with time.

Temporal Potential of Phragmites australis as a Phytoremediator to Remove Ni and Pb from Water and Sediment in Lake Burullus, Egypt

In the current work, we investigated the concentration of Ni and Pb in different organs of Phragmites australis to evaluate its potential application as a phytoremediator to remove these two metals from contaminated water and sediment in Lake Burullus (a Ramsar site in Egypt). Above- and below-ground biomass of P. australis, water and sediment were sampled monthly for 1 year at six sites of Lake Burullus (three sites represent each of the northern and southern parts of the lake) using six randomly distributed quadrats (each of 0.5 × 0.5 m) at each sampling site. Significant variation was detected for Ni and Pb concentrations in the sediments and waters between the northern and southern sites of the lake. The biomass of P. australis in the southern sites was greater than that in the northern sites; in addition, the above-ground biomass was higher than the below-ground biomass. The above-ground organs accumulated higher concentrations of Ni and Pb than the below-ground organs. The Ni and Pb standing stocks data indicated that the organs of P. australis extracted higher amounts of Ni and Pb per its area from the southern rather than the northern sites. In the current study, the Ni and Pb above-ground standing stocks increased from the early growing season (February) and reached its peak during August and then decreased. The highest monthly Ni and Pb standing stock (18.2 and 18.4 g m^- 2, respectively) was recorded in the above-ground organs of plants in the southern sites in August. The bioaccumulation factor of Ni was 157.6 and 153.4 in the northern and southern sites, respectively, whereas that of Pb was 175.3 and 158.3. The translocation factor of Ni and Pb from the below- to above-ground organs was generally > 1. Thus, this reed species is a potential candidate for Ni and Pb phytoextraction. Based on our results, P. australis could be used for the extraction of Ni and Pb to reduce the pollution in Lake Burullus, if the above-ground biomass is harvested at its maximum value in August, as was the case regarding the maximum standing stock of Ni and Pb.

Simulation-Based Solutions Reducing Soil and Groundwater Contamination from Fertilizers in Arid and Semi-Arid Regions: Case Study the Eastern Nile Delta, Egypt

Intensive agriculture requires increasing application of fertilizers in order to sustain food production. Improper use of these substances in combination with increasing seawater intrusion results in long-term and nonpoint soil and groundwater contamination. In this work, a 3-D groundwater and solute transport numerical model was created to simulate the effect of excessive fertilizers application along the Bahr El Baqar drain system, in the eastern Nile Delta, Egypt. The geotechnical properties of the soils, hydrologic parameters, and unconfined compressive strength were determined at different sites and used as input parameters for the model. Model results showed that silty clay soils are able to contain the contaminations and preserve the groundwater quality. Nevertheless, sandy soils primarily located at the beginning of the Bahr El Baqar drain allow leakage of fertilizers to the groundwater. Thus, fertilizer application should be properly managed in the top sandy layers to protect the groundwater and soil, as increasing aquifer by excess irrigation water increased the groundwater contamination in confined layers due to the high value of cumulative salt for the current situation while the unconfined zone decreased groundwater and soil contamination. A mass transport 3-D multi-species (MT3D) model was set to identify the optimal measure to tackle soil and groundwater contamination along the Bahr El-Baqar drain system. A potential increase of the abstraction rates in the study area has a positive impact in reducing the transfer of fertilizer contamination to groundwater while it has a negative impact for soil contamination. The scenario analysis further indicated that the installation of a drainage network decreases the groundwater and soil contamination. Both solutions are potentially effective for protection against nonpoint contamination along the Bahr El Baqar drain system. However, a more sustainable management approach of fertilizer application is needed to adequately protect the receptors located further downstream in the Nile Delta.

Drainage water salinity and quality across nested scales in the Nile Delta of Egypt

Improving water management depends on understanding the functioning of irrigation and drainage systems across different environmental scales. For this purpose, this study in the Nile Delta of Egypt particularly examines the spatial and temporal variation of drainage water salinity from the system to the plot level. A better understanding of this variation across nested scales is crucial to refine the government's drainage reuse strategy and reduce the adverse effects on agricultural productivity, lagoon ecology, and human health. The study investigates the drainage system of the Meet Yazid study area (82,740 ha) located in the upper central part of the Nile Delta. The parameters measured were electrical conductivity (EC), dissolved oxygen (DO), pH, and temperature. Results showed that salinity and quality of drainage water in the Nile Delta vary highly with space and time. The secondary drains exhibited the highest variability of salinity compared with main drains and subsurface drainage collectors because they accumulate salts from deeper soil layers and seepage of saline groundwater at the time of low flow discharge. In secondary drains, the salinity increased up to four times that of drainage water coming from the collectors. Moreover, DO values were most of the time not meeting standards for reuse in irrigation, especially at main drains that collect not only agricultural drainage but also untreated household sewage water.

Inferencing the land subsidence in the Nile Delta using Sentinel-1 satellites and GPS between 2015 and 2019

The Nile Delta is home to half of Egypt's population and has ample agricultural, industrial, and cultural resources, yet the land subsides in response to many natural and anthropogenic impacts. We report the recent subsidence rate and patterns in the Nile Delta using the synthetic aperture radar Sentinel-1 data of 144 images obtained between 2015 and 2019, based on coherence small baseline subset interferometry of ~2900 interferograms. We distinguished three patterns of deformation due to three different physical mechanisms: 1) The land subsides with rates ranging from -12 to -20 mm/year in major cities (such as Zagazig, Mit Ghamr, Tanta, Mansoura and Mahla) due to urban-induced loading; 2) A subsidence rate ranges between -3 and -8 mm/year along the coastal margins due to natural sediment dewatering and compaction. This rate is consistent with the global positioning system rate of -3.5 mm/year and 3) A subsidence rate ranges from -20 to -16 mm/year and -6 to -12 mm/year in newly reclaimed lands on the west and east of the delta's flood plains, respectively, due to groundwater overexploitation. Our findings, in contrast with results from previous studies of regional deformation mainly felt to be controlled by natural processes, demonstrate a localized subsidence and predominant anthropogenic control on the land deformation and call for revisiting sea level rise-related flooding models in the Nile Delta. In light of the new findings, the authorities should take necessary measures to reduce the ongoing land subsidence through enforcement of urban planning policies in the delta's flood plain and development of a sustainable management strategy for groundwater extraction.

Integration of remote sensing data and in situ measurements to monitor the water quality of the Ismailia Canal, Nile Delta, Egypt

The Ismailia Canal is one of the most important tributaries of the River Nile in Egypt. It is threatened by extinction from several sources of pollution, in addition to the intersection and nearness of the canal path with the Bilbayes drain and the effluent from the two largest conventional wastewater treatment plants in Greater Cairo. In this study, the integration of remote sensing and geospatial information system techniques is carried out to enhance the contribution of satellite data in water quality management in the Ismailia Canal. A Landsat-8 operational land imager image dated 2018 was used to detect the land use and land cover changes in the area of study, in addition to retrieving various spectral band ratios. Statistical correlations were applied among the extracted band ratios and the measured in situ water quality parameters. The most appropriate spectral band ratios were extracted from the NIR band (near infrared/blue), which showed a significant correlation with eight water quality metrics (CO₃, BOD₅, COD, TSS, TDS, Cl, NH₄, and fecal coliform bacteria). A linear regression model was then established to predict information about these important water quality parameters along Ismailia Canal. The developed models, using linear regression equations for this study, give a set of powerful decision support frameworks with statistical tools to provide comprehensive, integrated views of surface water quality information under similar circumstances.

Spatiotemporal dynamics of urbanization and cropland in the Nile Delta of Egypt using machine learning and satellite big data: implications for sustainable development

The Nile Delta of Egypt is increasingly facing sustainability threats, due to a combination of nature- and human-induced changes in land cover and land use. In this paper, an analysis of big time series data from remotely sensed satellite images and the random forests classifier was undertaken to assess the spatial and temporal dynamics of urbanization and cropland in the Nile Delta between 2007 and 2017. Out of thirteen variables, five spectral indices were chosen to build 500 decision trees, with a resulting overall accuracy average of 91.9 ± 1.5%. The results revealed that the urban extent in the Nile Delta has increased, between 2007 and 2017, by 592.4 km² (1.92%). Particularly, the results indicated that the years 2011 and 2012, which coincided the 2011 political uprising in Egypt, so-called the Arab Spring, were associated with significant land-use changes in the Nile Delta, both in rate and scale. As a result, the cropland area in the region decreased between 2010 and 2011 by 1.63% (502.21 km²). Moreover, the results showed that during the period 2012-2017, the mean annual urbanization rate in the region stood at 60 km²/year. In contrast, croplands decreased during the same period at an average annual rate of 2 km²/year. At the governorates' level, the results suggested that top agricultural producing governorates in the Nile Delta, such as Elmonoufia, Elkalubia, Elbouhyra, and Elghrbia, witnessed the highest rates of decrease in cropland areas during the period 2012-2017. Over the same period, urban areas increased the most in Elkalubia, Domiate, and Elmonoufia by 1.98%, 1.72%, and 1.34%, respectively. The f indings from this analysis are discussed along with their implications for sustainable land-use and urban planning policies.

Mobility, distribution, and potential risk assessment of selected trace elements in soils of the Nile Delta, Egypt

Environmental pollution has received considerable attention over the last 50 years. Recently, there has been an increasing interest in pollution of the Nile Delta, Egypt, which is one of the longest settled deltaic systems in the world. Pollution in the delta is increasingly recognized as a serious health concern that requires proper management of ecosystems. Therefore, this project aimed to study the distribution and assess the risk associated with selected trace elements (TEs) in different soils (i.e., marine, fluvial, and lacustrine parent materials) in the northern Nile Delta. Mehlich-3 extraction was used to determine the availability of antimony, vanadium, strontium, and molybdenum in agro-ecosystems in this area and their spatial distributions were investigated. Five indices were used to assess ecological risk. Results showed that TEs were higher in the southern part of the study area because it is affected by multiple pollution sources. The available concentrations of TEs were Sr < V < Sb < Mo. The bioavailability of Sr was highest among the studied TEs. The studied indices suggested the study area was moderately polluted by Sr and Sb. Furthermore, the results showed that marine soils had higher TE levels then lacustrine and fluvial soils. The ecological risk assessment indicated that V and Mo were of natural origin, while Sr and Sb were anthropogenically linked. Therefore, the situation calls for planning to reduce pollution sources, especially in the protected north Nile Delta, so these productive soils do not threaten human and ecological health.

Water quality observations in the marine aquaculture complex of the Deeba Triangle, Lake Manzala, Egyptian Mediterranean coast

Coastal aquaculture is faced with extreme variation in water quality. The Deeba Triangle on Lake Manzala is the largest marine coastal aquaculture-producing area on the Egyptian Mediterranean. Samples from 16 ponds were taken during four seasons (2014-2015), to investigate the variation of 12 water quality parameters at that region. We tested the hypothesis that there is no spatial or temporal variation in water quality of the fish ponds. Fish ponds were statistically clustered into three groups (p = 0.0005) coincident with their geographical location. Hypersaline and transparent waters characterized the western ponds; higher dissolved oxygen and higher nutrients characterized the central region. These spatial differences were principally due to variations in salinity and nutrients of the water sources used for irrigation of the ponds and to differences in the aeration management styles. Strong seasonality was seen in water temperature (following air temperature), nutrients, and turbidity (following the seasonal cycles of various water sources from the Lake Manzala and the seasonality of the petrochemical plants effluents close to these ponds). We conclude that municipal effluents significantly affected, spatially and temporally, the quality of the irrigation water used for coastal aquaculture purposes, which consequently might affect fish yield.

Epidemiology of bovine fascioliasis in the Nile Delta region of Egypt: Its prevalence, evaluation of risk factors, and its economic significance

Aim

This study focuses on the risk factors associated with the prevalence of Fasciola affecting cattle population in three provinces belonging to the Nile Delta of Egypt and to estimate the economic losses as a result of fascioliasis.

Materials and Methods

From January 2015 to end of December 2015, records of 21 farms (4976 cattle) were analyzed to screen the prevalence of fascioliasis among cattle farms, to identify its associated risk factors and its economic impacts on Nile Delta region of Egypt.

Results

The overall prevalence of fascioliasis in the Nile Delta region of Egypt was 9.77%. The prevalence of fascioliasis was found to be statistically significantly associated with age, sex, breed, and type of farms. The highest prevalence was observed in <2 age group (10.91%), and the lowest was >3 age groups (8.35%). In terms of body condition scores, cattle with medium and poor conditions were associated with fascioliasis more than those with good body condition. Besides, cattle raised in organic farms were associated with lower risk of fascioliasis than those in conventional farms. The prevalence of fascioliasis was noted more prominent in districts with moderate temperatures and with relative humidity (>60%). The annual overall costs for fascioliasis were estimated to be 221.2 USD/cow due to the significant reduction in body weight, reduction in milk production, and the treatment costs for fascioliasis.

Conclusion

The results provided could be helpful for improving the control and preventive strategies.

Population genetics of the Schistosoma snail host Bulinus truncatus in Egypt

The tropical freshwater snail Bulinus truncatus serves as an important intermediate host of several human and cattle Schistosoma species in many African regions. Despite some ecological and malacological studies, there is no information on the genetic diversity of B. truncatus in Egypt. Here, we sampled 70-100 snails in ten localities in Upper Egypt and the Nile Delta. Per locality, we sequenced 10 snails at a partial fragment of the cytochrome c oxidase subunit 1 gene (cox1) and we genotyped 25-30 snails at six microsatellite markers. A total of nine mitochondrial haplotypes were detected, of which five were unique to the Nile Delta and three were unique to Upper Egypt, indicating that snail populations may have evolved independently in both regions. Bayesian clustering and hierarchical F-statistics using microsatellite markers further revealed strong population genetic structure at the level of locality. Observed heterozygosity was much lower compared to what is expected under random mating, which could be explained by high selfing rates, population size reductions and to a lesser extent by the Wahlund effect. Despite these observations, we found signatures of gene flow and cross-fertilization, even between snails from the Nile Delta and Upper Egypt, indicating that B. truncatus can travel across large distances in Egypt. These observations could have serious consequences for disease epidemiology, as it means that infected snails from one region could rapidly and unexpectedly spark a new epidemic in another distant region. This could be one of the factors explaining the rebound of human Schistosoma infections in the Nile Delta, despite decades of sustained schistosomiasis control.

Bioaccumulation and translocation of heavy metals by nine native plant species grown at a sewage sludge dump site

In the present study, nine native plant species were collected to determine their potential to clean up nine heavy metals from soil of a sewage sludge dump site. Almost all nine plant species grown at sewage sludge dump site showed multifold higher concentrations of heavy metals as compared to plants grown at the reference site. All the investigated species were characterized by a bioaccumulation factor (BF) > 1.0 for some heavy metals. BF was generally higher for Cd, followed by Pb, Co, Cr, Cu, Ni, Mn, Zn, and Fe. The translocation factor (TF) varied among plant species, and among heavy metals. For most studied heavy metals, TFs were <1.0. The present study proved that the concentrations of all heavy metals (except Cd, Co, and Pb) in most studied species were positively correlated with those in soil. Such correlations indicate that these species reflect the cumulative effects of environmental pollution from soil, and thereby suggesting their potential use in the biomonitoring of most heavy metals examined. In conclusion, all tissues of nine plant species could act as bioindicators, biomonitors, and remediates of most examined heavy metals. Moreover, Bassia indica, Solanum nigrum, and Pluchea dioscoridis are considered hyperaccumulators of Fe; Amaranthus viridis and Bassia indica are considered hyperaccumulators of Pb; and Portulaca oleracea is considered hyperaccumulator of Mn.

Resistant Microbial Keratitis in South Nile Delta, Egypt: Influence of Regional Risk Factors

PURPOSE

This study was conducted in an attempt to identify the regional, geographic, climatic, socioeconomic, and other risk factors for microbial keratitis in south Nile Delta, Egypt.

METHODS

This is a prospective cross-sectional study that was carried out on 340 eyes of 340 patients with microbial keratitis attending at the outpatient clinic of Ophthalmology Department of Menoufia University Hospital during a period of three years between March 2010 and March 2013.

RESULTS

Epidemiological factors, lines of management, and follow-up results were recorded and statistically analyzed and there were regional variations in the prevalence, risk factors, and outcome in resistant corneal ulcers.

CONCLUSION

Higher incidence of affections and complications has appeared in farmers, rural area residents, and illiterates which are considered the main predisposing factors for ulcer resistance. According to culture results, bacterial organisms (especially Staphylococcus aureus) were the main cause of resistant corneal ulcers.