Flood Risk and Vulnerability of Jeddah City, Saudi Arabia

Abstract

Coastal cities are often vulnerable and subject to the risks associated with floods, hence the need to sensitize decision-makers on the threats posed by climate hazards and uncontrolled urbanization. This study is part of this logic and aims to identify and map the flood zones of the city of Jeddah in order to reduce their vulnerability and to integrate them into the strategies of prevention and fight against the risks of flooding. The recent floods in 2009 and 2011 have caused heavy human and material losses that will permanently mark the collective memory of the inhabitants of the city. The multisource and diachronic data used as well as the methodology adopted made it possible to perform a multi-criteria spatial analysis by combining optical satellite imagery and radar DEM, topographic and geological maps, rainfall records, and available statistical data. Thus, risk factors have been identified and combined to understand and appreciate the gravity of recent disasters and provide planners and decision-makers with tools to assist in the effective and adequate management of the ever-changing urban space, in a context of climate change and increased anthropogenic pressure on coastal cities.

Mid-Century Changes in the Mean and Extreme Climate in the Kingdom of Saudi Arabia and Implications for Water Harvesting and Climate Adaptation

“…Due to the heavy computational cost associated with our convection-permitting regional climate modeling, we perform simulations for two months (November and August) representative of wet (November-April) and dry-hot (May-October) seasons, respectively (e.g., [23]). We pick these two months based on the results of previous published work on historical climate analysis of KSA (e.g., [1,16]) (particularly around our five chosen sites) and based on discussions with our local co-authors, taking into account their experience with heat (temperatures + humidity) and precipitation events. To further confirm our choice of November and August, we also performed an analysis of annual cycle of monthly historical temperatures from climate reanalysis, ERA5 [47], and precipitation rates from GPM [33] during PD (2008-2017) averaged over KSA and verified that November is the wettest month and July and August are the hottest months, while daytime relative humidity is slightly higher in August based on daytime AIRS [50] retrievals (not shown).…”

“…Despite its desert climate, short-duration (3-5 h) intense bursts are known to comprise much of the total annual rainfall of a subregion (e.g., [3]), and several major cities in KSA experience extreme precipitation events that lead to flooding [1,13,14]. Recent frequent extreme precipitation events in Riyadh, the capital city, and Jeddah claimed several hundred lives, hundreds of residents went missing and these events led to significant damage to infrastructure and regional economy (e.g., USD 1 billion in monetary losses and USD 1.5 billion in damages and compensation for Jeddah floods in 2009) [15,16]. In Jeddah, the highest number of these extreme precipitation events occurred in November over the 1978-2012 time period [1].…”

“…In Jeddah, the highest number of these extreme precipitation events occurred in November over the 1978-2012 time period [1]. Between 1970 and 2014, the largest amount of average monthly rainfall per year was experienced in November [16].…”

L'urbanisation des zones côtières : utilisation des sols, implications morphologiques et environnementales. Le cas de la ville de Jeddah

“…Par ailleurs, l'extension de la ville sur le cours et l'exutoire de plusieurs oueds descendant des montagnes du Hedjaz, entraine des inondations catastrophiques lors des fortes et intenses précipitations qui tombent dans cette zone malgré l'aridité des conditions climatiques (Daoudi et Niang, 2019). Cette croissance urbaine vers la mer entraine également la disparition de plusieurs ilots notamment dans la baie de Jeddah et des perturbations de l'environnement marin (Mansour et Madkour, 2015).…”

Remote Sensing and GIS Contribution to a Natural Hazard Database in Western Saudi Arabia

“…For strengthening urban resilience planning such maps could be helpful by indicating those road segments that are susceptible to flooding in case of flash floods. Previous flooding events in this city in 2009 and 2011 with heavy human and material losses [41] have demonstrated the necessity of such maps. The source of tsunami waves, the direction of the incoming waves, and their height and energy cannot be predicted.…”