الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Monitoring sources of geo-environmental risks from rising groundwater levels and associated soil degradation is a substantial challenge in the coastal regions worldwide. The integration of remote sensing and subsurface data, followed by field geophysical surveys, provided an innovative approach for identifying sites susceptible to environmental risks from natural coastal interventions and anthropogenic activities. In this work, various remote sensing (Landsat-5-7-8 and ALOS/PALSAR DEM), and subsurface datasets (129 boreholes describing soil type, groundwater chemistry, and geotechnical clay plasticity) were manipulated and integrated into a Geographic Information System (GIS) environment to generate a Site Hazard Susceptibility Map (SHSM) for Suez city, Egypt, as an example of urban geohazard in coastal environments. The constructed LULC maps were deemed to be accurate with overall accuracies of over 92%. The change detection results indicate that the urban and vegetation areas were significantly expanded at the expense of dry soil due to rapid development projects over 32 years (1986-2018). The urban area increased dramatically from 28.04 to 52.06 Km2 by more than 80%, while dry bare soil declined by 47.33% over the study period 1986-2018. The vegetation area expanded by 14.52% during 1986-2000 and continued to increase by 25.15% until 2013, then declined by 4.08% in 2018. The soil water parameters and clay swelling factors of Suez (Egypt) clarified the broadest ranges with the highest standard deviations that exceeded the permissible limits of geotechnical hazards standards. Moreover, geotechnical properties show that these clay soils are inorganic clays of high plasticity and swelling (CH) potentiality. All factors were scored, weighted, and integrated to create SHS maps considering three standalone linear and statistical approaches, including simple additive weight (SAW), frequency ratio (FR), and index of entropy with information value models (IOE-IV). The constructed SHSM models were validated against the spatial distribution of affected infrastructures xv mapped by field observations and were found to provide accurate results. According to the AUC curves, the success rates of the SAW, FR, and IOE-IV models were 86%, 85.1, and 83.6%, respectively, indicating the high performance of FR over the other models. While the SAW method is recommended for the areas with limited validation data. Accordingly, the obtained very high susceptibility zone (around 11 % of the area) in both maps, was located in the El-Kapanon and south-eastern regions, showed permanent wetlands since 1986, shallow groundwater level, and marine soil facies with thick clay. These conditions enhanced the risk of water salinity and swelling potentiality even without anthropogenic intervention. Additionally, seven Electrical Resistivity Tomography (ERT) profiles, collected over the vulnerable sites using Dipole-Dipole and Wenner-Beta arrays, showed the presence of a buried paleo-sand channel extending from the Gulf of Suez and acting as a conduit for seawater inundation during winter seasons. These results highlight the significance of the proposed approach as a practical and cost-effective tool for coastal vulnerability mapping to better understand the complexity of multi-dimensions criteria for geohazard modelling. This holistic approach is an important phase to guide priorities of urban planning and would improve the analysis of coastal vulnerability and could be employed in other coastal cities worldwide.