By Staff Reporters

Given the huge costs to people and property when it floods, a question arises, can flooding be prevented or can we even know precisely when and where it will hit?

European Commission’s Horizon 2020 programme Hydrology Professor Hannah Cloke says despite the work of some of the brightest scientists, the world’s most advanced supercomputers and the commitment of hardworking people on the ground, floods are difficult to predict and prepare for.

“They always have – and we know that as the global climate warms due to human activity we are likely to  see more of some types in Britain. It’s hard to convince people who don’t know they are at risk that they should prepare for the worst.

“This is where government must step in. To better prepare for floods, we need difficult, expensive, but rational decision-making on flood defences,” she said. 

Writing for theconverstion.com, academics Garikai Martin Membele, Maheshvari Naidu and Onisimo Mutanga say local indigenous knowledge systems could be useful in prediction and better managing flood disasters. 

“A geographical information system creates, analyses and maps all types of data. This includes data on floods and areas vulnerable to flooding. It can be drawn on when engaging stakeholders and educating the public about how human and environmental systems interact. But a geographical information system on its own is not able to explain the human factors that cause flood vulnerability. Hence the need for local or indigenous knowledge,” the scholars say.

They argue indigenous knowledge is strongly linked to local culture and past experiences, and therefore it can be a source of resilience to flooding and other natural disasters.

“South Africa’s laws and regulations make provision for using indigenous knowledge in reducing flood disaster. But the use of this approach is still relatively low. In many cases it is non-existent, especially in urban areas,” they say. 

They attribute the severity of the flood disasters to marginalisation of the majority black poor communities, saying flooding is made more problematic by informal settlements because of the lack of planning by government.

“Historically, the apartheid regime legally compelled people classified as black Africans to live in marginalised settlements and restricted their movements. Because housing wasn’t planned or provided, informal settlements emerged.

“As in other sub-Saharan cities, the poorer communities in Durban mainly live in informal settlements. This is because local planning authorities are unable to keep up with the increasing demand for accommodation as people move to the city. 

“According to city reports, between 2016 and 2019, the local authority managed to build only an average of 4,000 houses a year. This means the city has a backlog of more than 440,000 houses. It could take decades to clear,” they said.

The scholars say mapping or spatially visualising the patterns with the use of geographic information systems and levels of flood vulnerability can identify the people who need the most help. This can assist local government and other stakeholders to formulate policies and strategies that reduce the impact of floods on people.

“Unfortunately, the reality is that flooding will increase in many parts of the world due to climate change. There is thus a need for stakeholders at various levels to come up with ways of reducing people’s vulnerability. Increasing people’s coping and adaptive capacity is one of the key ways of promoting resilience,” the academics said.

They say there is  a need for a bottom-up approach in dealing with potential flood disaster management in informal settlement areas. Knowledge based on familiarity with the place offers a number of advantages:

• it provides a culturally appropriate response
• is socially inclusive 
• is cost-effective
• is a participatory way of reducing flood vulnerability, especially in informal settlements 
• promotes community members’ participation in finding solutions that work where they live 
• provides city planners with information on the spatial pattern as well as locally specific factors that cause flooding and damage in particular geographical areas. 

The mapping of floods by integrating the indigenous knowledge of local communities is an approach that potentially has much to offer flood disaster management.