• Energy Research
• 14. Life underwater close
• 11. Sustainability close

Assessing soil quality is considered one the most important indicators to ensure planned and sustainable use of agricultural lands according to their potential. The current study was carried out to develop a spatial model for the assessment of soil quality, based on four main quality indices, Fertility Index (FI), Physical Index (PI), Chemical Index (CI), and Geomorphologic Index (GI), as well as the Geographic Information System (GIS) and remote sensing data (RS). In addition to the GI, the Normalized Difference Vegetation Index (NDVI) parameter were added to assess soil quality in the study area (western part of Matrouh Governorate, Egypt) as accurately as possible. The study area suffers from a lack of awareness of agriculture practices, and it depends on seasonal rain for cultivation. Thus, it is very important to assess soil quality to deliver valuable data to decision makers and regional governments to find the best ways to improve soil quality and overcome the food security problem. We integrated a Digital Elevation Model (DEM) with Sentinel-2 satellite images to extract landform units of the study area. Forty-eight soil profiles were created to represent identified geomorphic units of the investigated area. We used the model builder function and a geostatistical approach based on ordinary kriging interpolation to map the soil quality index of the study area and categorize it into different classes. The soil quality (SQ) of the study area, classified into four classes (i.e., high quality (SQ2), moderate quality (SQ3), low quality (SQ4), and very low quality (SQ5)), occupied 0.90%, 21.87%, 22.22%, and 49.23% of the total study area, respectively. In addition, 5.74% of the study area was classified as uncultivated area as a reference. The developed soil quality model (DSQM) shows substantial agreement (0.67) with the weighted additive model, according to kappa coefficient statics, and significantly correlated with land capability R2 (0.71). Hence, the model provides a full overview of SQ in the study area and can easily be implemented in similar environments to identify soil quality challenges and fight the negative factors that influence SQ, in addition to achieving environmental sustainability.

The role of heritage sites as a shelter for biodiversity is overlooked. Eight archeological sites representing different landscapes in Alexandria City were surveyed, from which 59 stands were sampled between April 2019 and March 2021. The archeological sites and the relictual landscapes are geographically dispersed and are arranged here from west to east, representing the full range of environmental variation within the study area. The selection of stands in each site was based on the area and the variability within the habitats, the physiography, and the levels of disturbance. A composite soil sample was collected from each site. Two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DECORANA) were carried out to identify the plant communities in the study area. The recorded taxa, their national geographical distribution, life forms, habitats, chorological types, and vegetation groups are listed. A total of 221 specific taxa, 172 native and 49 alien non-native species (representing some 10.3% of the whole range of Egyptian flora), belonging to 150 genera and 44 families, are reported in the present study. Only two endemic species were recorded in the studied urban habitats. The phytosociological analysis of the sites showed differences among vegetation types found in the archeological sites as a function of the varying degrees of enthronization. A significant effect of archeological site and relictual landscape on species diversity was observed as indicated using the richness, Shannon’s and Simpson’s indices. Flat plains are substantially more diverse than any of the other habitats in the present study, followed by the habitat of rocky ridge slope. The present study found evidence of an ecological legacy that persists today within the semi-arid climatic ecosystem of Alexandria City. The study highlights the urgent need for measures to maintain cultural landscapes while considering the conservation of biodiversity within the archeological sites. It is hoped that the outcomes of the current study can provide guidance on the potential integration of biodiversity conservation in planning the management of archeological sites.

The current study investigated the nutrients removal efficiency of the sedge macrophyte Cyperus alopecuroides to treat water eutrophication, besides evaluating the recycling possibility of the harvested material. Samples of sediment, water, and plant tissues were taken seasonally from six polluted and three unpolluted locations for this investigation. The growth properties of C. alopecuroides showed remarkable seasonal differences in plant density and biomass, with the maximum values (7.1 individual/m2 and 889.6 g/m2, respectively) obtained during summer and the minimum (4.1 individual/m2 and 547.2 g/m2, respectively) in winter. In polluted locations, the above-ground tissues had an efficiency to remove more contents of N and P (11.9 and 3.8 g/m2, respectively) than in unpolluted ones (7.1 and 3.4 g/m2, respectively). The high-nutrient standing stock of C. alopecuroides supports its potential use for nutrient removal from eutrophic wetlands. The tissues of C. alopecuroides had the maximum nutrients removal efficiency to remediate great amounts of Na, K, and N in summer, and Ca, P, and Mg in spring. Above- and below-ground parts of C. alopecuroides from unpolluted locations can be considered as a rough forage for beef cattle, dairy cattle, goats, and sheep. The present study indicated the potential of C. alopecuroides in restoring eutrophic freshwater ecosystems, and, thus, it can be used in similar habitats worldwide.

To better assess the relationship between excess nutrient runoff and plant species diversity in the Egyptian northern coastal lakes, the relationships between aboveground biomass, species diversity, and both micro and macronutrient concentrations in sediment, water, and plant materials were investigated. A total of 38 sampling sites were established for the five Egyptian northern lakes (8 for Bardawil, 10 for Manzala, 8 for Burullus, and 6 for each of Edku and Mariut). Sediment, water, and plant materials were collected and analyzed for both micro and macronutrients including nitrogen (N), phosphorus (P), sulfur (S), magnesium (Mg), calcium (Ca), potassium (K), iron (Fe), boron (B), sodium (Na), and aluminum (Al). Based on the Sørensen similarity index, Burullus and Mariut lakes were very similar (0.70) in their vegetation composition, while Bardawil Lake had no similarity with the rest of the lakes. In sediment, Mariut Lake had the highest total P concentrations (1.3 g kg−1), while Bardawil Lake had the lowest (0.3 g kg−1). Bardawil, a hypersaline lake, had the highest concentrations for both Na and B (9.6 and 0.1 g kg−1, respectively). Among the deltaic lakes, Mariut Lake water bodies had the lowest plant species richness. The current study indicated that the excessive agricultural and industrial nutrient runoff had a greater impact on the nutrient distribution pattern and negatively impacted plant species diversity at the Egyptian coastal lakes. An integrated management plan, including establishing more pretreatment facilities for runoff and wastewater, should be implemented to reduce the nutrient loads from the main industrial and agricultural runoff sources. Moreover, periodic monitoring and assessment for nutrient runoff reaching the lakes are necessary to help reduce eutrophication levels.

Food waste has become a challenging global issue due to its inefficient management, particularly in low and middle-income countries. Among food waste items, fruit peel waste (FPW) is generated in enormous quantities, especially from juice vendors, resulting in arduous tasks for waste management personnel and authorities. However, considering the nutrient and digestible content of organic wastes, in this study four types of FPW (pineapple: PA; sweet lemon: SL; kinnow: KN; and pomegranate: PG) were investigated for their potential use within biogas production, using conventional and electro-assisted anaerobic reactors (CAR and EAR). In addition, the FPW digestate obtained after the biogas production experiments was considered as a soil bio-fertilizer under radish (Raphanussativus L. cv. Pusa Himani) cultivation. In the results, all four types of FPW had digestible organic fractions, as revealed from physicochemical and proximate analysis. However, PA-based FPW yielded the maximum biogas (1422.76 ± 3.10 mL/62.21 ± 0.13% CH4) using the EAR system, compared to all other FPW. Overall, the decreasing order of biogas yield obtained from FPW was observed as PA > PG > SL > KN. The kinetic analysis of the biogas production process showed that the modified Gompertz model best fitted in terms of coefficient of determination (R2 > 0.99) to predict cumulative biogas production (y), lag phase (λ), and specific biogas production rate (µm). Moreover, fertilizer application of spent FPW digestate obtained after biogas production significantly improved the arable soil properties (p < 0.05). Further, KN-based FPW digestate mixing showed maximum improvement in radish plant height (36.50 ± 0.82 cm), plant spread (70.80 ± 3.79 cm2), number of leaves (16.12 ± 0.05), fresh weight of leaves (158.08 ± 2.85 g/plant), fruit yield (140.10 ± 2.13 g/plant), and fruit length (25.05 ± 0.15 cm). Thus, this study suggests an efficient method of FPW management through biogas and crop production.

Lake Burullus is the second largest lake at the northern edge of the Nile Delta, Egypt, and has been recognized as an internationally significant wetland that provides a habitat for migrating birds, fish, herpetofauna, and mammals. However, the lake is experiencing severe human impacts including drainage and conversion to agricultural lands and fish farms. The primary goal of this study was to use multispectral, moderate-spatial-resolution (30 m2) Landsat satellite imagery to assess marsh loss in Lake Burullus, Egypt, in the last 35 years (1985–2020). Iterative Self-Organizing Data Analyses (ISODATA) unsupervised techniques were applied to the Landsat 5 Thematic Mapper (TM) and Landsat 8 Operational Land Imager–Thermal Infrared Sensor (OLI–TIRS) satellite images for classification of the Lake Burullus area into four main land-use classes: water, marsh, unvegetated land surfaces (roads, paths, sand sheets and dunes), and agricultural lands and fish farms. The overall classification accuracy was estimated to be 96% and the Kappa index was 0.95. Our results indicated that there is a substantial loss (44.8% loss) in the marsh aerial coverage between 1985 and 2020. The drainage and conversion of wetlands into agricultural lands and/or fish farms is concentrated primarily in the western and southern part of the lake where the surface area of the agricultural lands and/or fish farms doubled (103.2% increase) between 2000 and 2020. We recommend that land-use-policy makers and environmental government agencies raise public awareness among the local communities of Lake Burullus of the economic and environmental consequences of the alarming loss of marshland, which will likely have adverse effects on water quality and cause a reduction in the invaluable wetland-ecosystem services.

AbstractCoastal ecosystems are characterized by high content of soil carbon storage; however, they experience severe land conversions in the past decades. The current study aims to examine how different land use/land cover (LU/LC) impact carbon stock in coastal ecosystem along Jazan coast, Saudi Arabia. In this study, impacts of LU/LC on carbon stocks in the coastal zone of Jazan, Saudi Arabia in 2009, 2013, and 2021 were assessed. Also, the LU/LC dynamics were evaluated using data provided by the land use dynamic model. The carbon stocks were modelled based on LU/LC using the InVEST program. Our study results showed that the decrease in mangroves from 2013 to 2021 reflects the high atmospheric emissions of carbon dioxide (CO2). Also, the increase in built-up areas might negatively impact total carbon stock. The estimated carbon stocks for the coastal zone of Jazan biome were 7279027.42 Mg C in 2009 (1Mg = 106 g). It decreased to 2827817.84 Mg C in 2013, with a total loss of − 4450675.40 Mg C, and an average of annual loss of − 1,112,669 Mg C in the study period with net value of − 461240790.53 US$. On the other hand, the total estimated carbon stock was increased from 2013 to 2021 with a 3772968.31 Mg C in 2021 (a total gain 944840.87 Mg C). Based on the current findings, we recommend that land-use-policy makers and environmental government agencies should implement conservation policies to reduce land use change at Jazan coastal ecosystems.

Standard methods are limited for monitoring and managing water quality indicators (WQIs) in real-time and on a large scale. Consequently, there is an urgent need to use reliable, practical, swift, and cost-effective monitoring tools that can be easily deployed and assist decision makers in assessing key indicators relevant to surface water quality in a comprehensive manner. Surface water samples were collected and evaluated for water quality at 16 distinct sites across the Qaroun Lake in 2018 and 2019. Different WQIs, including total dissolved solids (TDS), transparency, total suspended solids (TSS), chlorophyll-a (Chl-a), and total phosphorus (TP), were tested for aquatic utilization. An integrated approach comprising WQIs, geospatial techniques, hyperspectral reflectance indices (SRIs) (commonly used SRIs, two-band and three-band SRIs (Spectral index calculated from water spectral reflectance of two or three wavelengths)), and partial least square regression (PLSR) models were used to assess the water quality of Qaroun Lake. According to the findings, the water quality attributes are polluted to varying degrees. The majority of commonly used SRIs presented moderately relationship with four WQIs (transparency, TSS, Chl-a, and TP) (R2 = 0.45 to 0.64), while the majority of newly two-band SRIs (NSRIs-2b) indicated moderate to strong relationships with WQIs (R2 = 0.51 to 0.74), and the majority of newly three band SRIs (NSRIs-3b) presented strong relationships with WQIs (R2 = 0.67 to 0.81). Broadly, the highest coefficients of determination were noticed with the NSRIs-3b followed by the NSRIs-2b and then the commonly used SRIs. For example, the NSRIs-3b (NDSI648,712,696) had stronger relationships with transparency, TSS, and Chl-a with R2 = 0.77, 0.66, and 0.81, respectively, than other SRIs. In addition, the NSRIs-3b (NDSI620,610,622) showed the highest R2 of 0.73 with TSS. The NSRIs-3b coupling with PLSR predicted the WQIs with satisfactory accuracy in the calibration (reach up R2 = 0.85) and validation (reach up R2 = 0.81) datasets. The overall findings of this research study showed that deriving an optimized NSRIs-3b from spectrum region and combining it with PLSR model could be a practical tool for managing water quality of the Qaroun Lake by accurately, timely, and non-destructively monitoring the WQIs.