Spatial analysis and modeling of environmental contamination in Alexandria Governorate at the Northwestern Nile Delta Coast, Egypt

Abstract Understanding the spatial dynamics of pollution is vital for managing urban environmental risks in rapidly developing coastal regions. This study integrates field surveys, laboratory analyses, and remote sensing of water, soil, and air parameters within novel GIS-based ecological models to produce combined water, air, and soil contamination maps for Alexandria Governorate. Two field trips (September 2022 and January 2023) were conducted to the governorate, surveying 64 locations. A total of 64 environmental samples (33 soil, 31 irrigation water) were collected and analyzed for heavy metals (Cd, Ni, Pb, Fe, Cu). Soil pollution was assessed using multiple indices: contamination factor (CF), degree of contamination (DC), ecological risk (ER), risk index (RI), enrichment factor (EF), pollution load index (PLI), and geo-accumulation index (Igeo​). Additionally, ambient air quality parameters (particulates and gases) were measured in-situ in January 2023. Inverse Distance Weighting (IDW) was used for geostatistical mapping. Water quality exhibited high fluctuation (e.g., EC 662.00 to 14920.00 µs/cm), ranging from good to unsuitable for irrigation, likely due to varying site activities. Spatial analysis of soil metals revealed elevated levels of Cr (> 0.04 ppm), Fe (> 2 ppm), and Pb (0.07 ppm) in America 1, 2, and Montazah 2. Soil pollution generally increased from south to north for Fe, Cu, and Ni, while Pb levels were high in both northern and southern agricultural areas. Air quality analysis showed a high mean concentration for PM 10 ​ (483.50 µg/m 3 versus PM 2.5 ​ at 38.42 µg/m 3 ). Mean levels of CO, CO 2 ​, NO, NO 2 ​, and O 3​ (1.71,352.56,0.040,0.002, and 0.001 µg/m 3 , respectively) remained below Egyptian thresholds. Overall, the environmental pollution risk increases northward, with the highest risks concentrated in the densely populated Montazah 1, 2, and Raml 2 districts.