Management strategy for the annual flood risk of informal settlements in South Africa: a case study of Alexandra Township, Gauteng Province

Abstract

Floods are natural catastrophic events that cause severe consequences for humans. Floods cause damage to infrastructure, roads, and result in life loss. Alexandra Township is prone to floods. Between 2016 and 2018, heavy rain has caused the Jukskei River to burst its banks. A Geographic Information System (GIS) tool is utilized to map out locations that are vulnerable to floods. Using an aerial shot and a 1:100-year floodline as the base map layer in ArcGIS, a spatial analysis of the regions that are vulnerable to floods was carried out. The outcomes charted the susceptibility of properties located in floodplains. Affected families were given questionnaires as part of a quantitative survey technique to determine community coping mechanisms, indicators, and factors that contribute to flood susceptibility. In addition, a qualitative survey was conducted to round out the data collected from the quantitative survey. In order to gather information on indicators, flood experience, adaptability, and mitigation strategies, key informant interviews were carried out with disaster management authorities in the research region. To study the physical landscape and the effects of flooding, field observations were conducted. Secondary data were obtained from the South African Weather Service and maps. The absence of planning has resulted in inadequate dwelling unit layout and structure, making people more susceptible to other hazards beyond floods. Their socioeconomic background and dense population have made them more vulnerable because they depend on each other for daily survival. Recommendations were given based on the study's main conclusions. This study makes several adaptation and mitigation suggestions which may be applied to lessen inundation susceptibility whilst avoiding flood-related negative consequences. The study shows that locals were not totally unaware of the floods, but public sharing activities are still required. The following are the main suggestions for this research: o The community should be regularly updated on the disaster awareness program and given more attention. o To better manage and prepare for floods, household socio-economic conditions must be considered. - iii - o Authorities must deter and prevent people from settling in dangerous areas close and along the riverbanks. Flooding is a natural occurrence that will always happen after a heavy rain. Although we cannot stop floods from happening, we can control or reduce how vulnerable households are to them. This can be done by preventing floods from reaching people and preventing people from being affected by floods. The community will benefit in the long run from preventing floods, even though it can be a lengthy project because it involves expensive technological investments such as trapping excess water using a dam or building canals. Additionally, since there is no other land available for development or the construction of residential properties except the Jukskei River, squatter communities have also sprung up there. We can conclude that changes in land cover classes and population change are strongly correlated. The case studies made it abundantly evident that the use of ArcGIS is crucial in the collection of data for flood management. The research study's conclusions could be used as standard procedures to develop a more focused, well-informed intervention program that will aid in determining how recurrent flooding affects communities and in managing flood disasters.