الفهرس 
Chapter (1): IntroductionOnly 14 pages are availabe for public view
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Abstract
Alexandria, which is located on the Mediterranean Sea, is the second-largest city in Egypt. It is exposed to a high rate of rainfall annually compared with other governorates. Extreme storm impacted the area in 2015, flooding most of the city’s urban areas significantly. The effects on social and economic activities are extremely negative. The city was not well prepared for extreme event.By developing flood susceptibility maps for Alexandria city using geographic information systems (GIS) and remote sensing applications (RS), this study intends to assist decision makers set priority strategies. Two models have been developed to meet the main objective of the study, and the results of the two models have been compared. The first model uses GIS, RS, and integration with a multi-criteria decision-making process to generate flood susceptibility mapping for Alexandria city. Following a review of the relevant research and a technical conversation with specialists, the analytic hierarchy process (AHP) technique and the list of important urban flood factors are developed. The necessary data for each factor is obtained using RS techniques. To get the final weights for each element, a quantitative analysis applying the AHP approach is utilized. Using the GIS system, a spatial data analysis is carried out to pinpoint multiple factors of the susceptibility map. The rainfall has the highest probability of flooding, according to the analytical hierarchy process (AHP) method, with a priority weight of 38%. This is due to the factor’s significance in the flood trigging, which is followed by the distance to the stream with a weight of 26.3% and the slope with a weight of 13.4%. Elevation and land cover-land use had priority weights of 11.5% and 10.8%, respectively, making them the least significant factors. Alexandria is divided into three zones on the susceptibility map according to the likelihood of urban flooding: high, moderate, and low.
This classification map of Alexandria is intended to assist decision-makers in establishing priorities and putting effective strategies into action to mitigate the effects of the flooding.
The Second model is estimating the Flood Vulnerability Index (FVI) for Alexandria. Three components are used to classify the degree of vulnerability during the study: the social, the physical, and the environmental components. The indicators are thoroughly specified to calculate the levels of susceptibility, exposure, and resilience. The influencing factors are then identified to determine the levels of vulnerability to each indicator. These factors are population, population density, the percentage of the population served by sanitation, warning systems, proximity to stream, elevations, rainfall, slops, land use, urban growth, and recovery time to flood. RS is used to collect the data required to determine some of these factors.
Each factor has been divided into weights for each grade. The GIS divides the study area into sixteen groups based on its administration classification. The social, physical, and environmental components of each of the three flood vulnerability factors have been estimated, and the combined FVI of each of the sixteen regions has been estimated.
The results demonstrate that calculation of exposure is a method of assessing and determining the degree of vulnerability to floods to arrange and identify appropriate adaptation plan options by decision makers. The degree of FVI indicates the risk of urban floods from the lowest to the highest levels.
Finally, the findings from the developed susceptibility map and the estimation of the flood vulnerability index are compared for Alexandria City.
The model’s findings could assist the Holding Company for Water and Wastewater make decisions in establishing priorities and putting effective strategies into action to mitigate the effects of the flooding.