Ms Khulukazi C. Hlalukana

Level of Study: 
Geographical Information Systems (GIS) & Remote Sensing
Flood risk assessment using Remote Sensing and GIS: A case study of Richards Bay, KwaZulu Natal Province, South Africa

Natural hazards including floods are an inevitable phenomena and risk associated with floods is expected to increase in river basins due to climate change characterised by increasing rainfall.  Flooding causes a range of difficulties including loss of human life, damage to vehicles and infrastructure, as well as associated economic losses. Therefore, there is a need to perform flood risk assessments as a preparatory and protective management tool for efficient decision making. In KwaZulu-Natal, flood risk assessment is a low priority in comparison to other development pressures, despite the intrusion of informal settlements and peri-urban sprawl into flood-prone areas. Richards Bay in particular, is notably prone to future flooding due to the continued growth and development in a floodplain area hence its selection for the study. The study uses remote sensing (RS) and Geographic Information Systems (GIS) to assess flood risk by objectively defining a baseline for flood events and modelling flood prone areas.  It is envisioned that the baseline will be defined by identification of changes in flood risk between 2016 and 2017 using sentinel imagery to observe likely trends from flood sources, whilst the flood prone areas will be modelled using logistic regression model. Factors such as, flow accumulation, rainfall intensity, geology, slope and land use/land cover and in addition, Tropical Rainfall Measuring Mission (TRMM) data will also be used to identify the rainfall intensity for the period 2010 to 2017. Rainfall trends will then be plotted for all the years to determine months with highest precipitation. Hazardous areas will then be estimated based on proximity to the river to create the final flood risk map.