Mapping of Flood Zones in Urban Areas through a Hydro-climatic Approach: the Case of the City of Abha

Abstract

Flooding is a natural phenomenon of the hydrological cycle, but it has become an urban concern in many cities around the world. Due to human intervention on the functioning of hydrosystems through infrastructure, the channelling of watercourses, the redirection of the flow and the inevitable extension of the urban landscape, floods have become a growing urban hazard. Several cities are currently facing very frequent flash floods. These floods are of various types and several factors are at the origin of their manifestation, which leaves its understanding and prevention for local stakeholders a long-term process that requires a colossal amount of work among several multidisciplinary researchers. Without denying the scientific consensus on the role of climate change, currently floods are largely caused by the senseless and irresponsible behaviour of humans. Among the cities in Saudi Arabia facing the risk of flooding is the city of Abha located in the southwest of the country, the focus of this research. It is subject to recurrent and devastating floods caused by several factors. Controversial topography, dissected orography, aggressive rainfall, accelerated and unregulated urban growth, and irresponsible human intervention are all factors that aggravate this problem. The resolution of this problem, or at least the minimization of its consequences, requires a rigorous and carefully studied approach. The appropriate knowledge by local stakeholders must be reinforced by a methodological and cartographic assessment of this phenomenon in order to mitigate its consequences. The main objective of this work is to make cartographic and methodological contributions to acquire additional knowledge on the flood hazard in the city of Abha through a statistical processing of rainfall data for the period 1978-2018, a mapping of the factors intervening on the runoff and its various behaviors and finally a synthetic analysis.

Insights into soil loss in the Jouah basin using EPM model and Caesium 137 as an isotopic tracer

“…It drains an area of 30 km 2 and is one of the main tributaries of the downstream course of the Wadi Jīzān in south-west Saudi Arabia (Figure . 1). The Jīzān region was subjected to several hydrological (Abdelkarim, 2019;Allaoua and Azaiez, 2021), rural and environmental studies that focused particularly on soil and groundwater pollution as well as salinity risk and agriculture. (Khaled et al, 2016;Al Zahrani, 2018;Al-Boghdady, 2019).…”

Flash Flood Assessment and Management for Sustainable Development Using Geospatial Technology and WMS Models in Abha City, Aseer Region, Saudi Arabia

“…The slope ranged from 0.01 to 53.35 degrees (Figure 2b). The high elevation, high depth valleys [75], weather fluctuation, deep watercourses, and urbanization. As evident from Figure 2a, Abha has a variety of topographical elevations that result in urbanization.…”

“…The majority of Abha city was seen covered in runoff due to flash floods (Figure 4). The AlMahala area (facing the outlet point) was the confluence of several streams and was considered a permanently flooding zone [75]. Surface water elevations exceed 1.49 m between the AlMahala and Bani Mazen regions (Figure 1), particularly at river saddles and confluences.…”

“…The soil clay is primarily composed of smectite, illite, and partially kaolinite, and it has a low permeability, which increases the risk of flooding (Figure The slope ranged from 0.01 to 53.35 degrees (Figure 2b). The high elevation, high depth valleys [75], weather fluctuation, deep watercourses, and urbanization. As evident from Figure 2a, Abha has a variety of topographical elevations that result in urbanization.…”

Contribution of soil physical properties in the assessment of flood risks in tropical areas: case of the Mbo plain (Cameroon)

“…These are soil, relief, hydrography with rain as a trigger (Wolting 2000;Leumbé Leumbé et al 2015;Zogning et al 2015;Lamachere 1988). For others, flooding is due to land-use change and human activity (Tchotsua 1996;Tchotsua 2007;Mendonca et al 2015;Mwazvita et al 2018;Sighomnou et al 2012;Zehra et al 2019;Ansar et al 2021). These works corroborate those of Montoroi (2012) who believes that the nature of the soil and its spatial distribution play a dominant role on the genesis of floods.…”