Slum housing next to a polluted stream in Indonesia
Slum housing next to a polluted stream in Indonesia

The power of local knowledge

How can identifying plastic waste, the water hyacinth, and changes in water colour help to reduce the damage caused by flooding and landslides?

Did you know that Indonesia plans to build a new national capital city? 'Nusantara' is bound to move 30 million inhabitants out of Jakarta, as the current capital is expected to be submerged and uninhabitable by 2050 due to flooding and landslides. Indonesia's flooding problem is massive, and its solutions are accordingly. However, how do informal Indonesian settlements like slums deal with flooding when local governments do not acknowledge or support them? Radboud researcher and anthropologist Elizabeth MacAfee aims to foster more understanding for these marginalised groups. 

By studying the mismanagement of plastic waste in informal settlements in Pontaniak and Manado, MacAfee points out how crucial local knowledge is to recognise and act on flooding. Together with a local research assistant who's fluent in Bahasa Indonesia, she conducted around 70 in-depth interviews with locals. It's part of a bigger project called RISE (Resilient Indonesian Slums), which studies water-related problems and their impact on low-income informal settlements in Indonesia. 

How does plastic waste connect to urban flooding and landslides? 

Water is a continuous topic in MacAfees' research. In terms of flooding in Pontaniak and Manado, she points out that scientists usually describe three types: rainfall, river overflow, and the rise of sea level. 

How can plastic waste as a thing in itself contribute to flooding in these urban areas? MacAfee explains: 'After flooding or a landslide, plastic waste and other trash left behind can block and obstruct drainage pathways, preventing water from flowing freely and intensifying its effects. It can also trigger landslides because the accumulating water weakens the soil.' She continues, 'Plastic production releases greenhouse gasses that contribute to extreme rainfall events, increasing flood risks.' 'One of the big reasons plastic waste keeps appearing is the lack of good alternatives for garbage disposal in informal settlements. Residents must transport their waste long distances to narrow streets, where it is not collected. 'This mismanagement drives people to pollute, not because they don't care, but because they have no other choice, MacAfee clarifies.'  

'Mismanagement drives people to pollute, not because they don't care, but because they have no other choice'

It isn't about not caring enough

'However, blaming the local minorities in Manado and Pontaniak for pollution and its effects is unfair', MacAfee states. 'Systematic changes are needed to encourage better choices, like making sustainable options financially or practically attractive'. 

She continues: 'If anything, these residents have shown us the opposite of 'not caring'. From an outsider's perspective, people who live in informal settlements don't care about the environment and act irrationally because they choose to live in an unsafe place. But, the locals have an in-depth understanding of the complicated dynamics that are going on around them'. 

The water hyacinth: why local knowledge is important

'For instance, scientists in technical landslide classifications often overlook plastic waste as a triggering or contributing factor for a landslide risk. This highlights the significance of local knowledge, which should be given the same importance as that of non-local scientists.', MacAfee explains. 

She continues, 'Locals can spot colour changes in the water. If they see it become muddy, they know the flooding is caused by heavy rain upstream. If it becomes clearer, they know the tide is coming up, and the flooding is caused due to a rise in sea level. That practical knowledge provides a quick understanding of the direction of the flood and can be crucial when acting upon it'. 

'That practical knowledge provides a quick understanding of the direction of the flood and can be crucial when acting upon it'

During her exploration, MacAfee encountered another fascinating case of local expertise - identifying the water hyacinth floating in the river. This plant is an invasive species that thrives in the lake at the head of the Tondano River. As the water flows downstream over the dam, the plant travels with it and can be easily identified by the locals as a sign of flooding.

'It demonstrates the locals' nuanced, interesting, and complex understanding of their environment', MacAfee concludes. 

Why anthropological research? 

When dealing with environmental issues like flooding and landslides, it is crucial to consider the knowledge and perspectives of local communities, especially those who are marginalised or live in informal settlements.

MacAfee explains, 'In the field, when you speak and connect with people, you can zoom in, reveal hidden information, and question things the majority might take for granted. After interviews, we tend to stay in the area, have lunch together, and informally chat with each other as well. Witnessing these people's daily struggles and conditions can help you see things differently.' When discussing flooding, we have to start from a point where we treat the locals' perception as equally valuable as the scientists. Anthropological research highlights the importance of combining local insights with scientific expertise'.

'When discussing flooding, we have to start from a point where we treat the locals' perception as equally valuable as the scientists. Anthropological research highlights the importance of combining local insights with scientific expertise'

Towards a more equitable and sustainable future 

By engaging with residents and understanding their experiences, we can better understand environmental dynamics and effective ways to reduce the impact of such events. Additionally, establishing collaborations between researchers and local communities can enhance scientific understanding and promote more equitable, sustainable solutions for a better future.

You have a part to play

Our society is facing major challenges. Radboud University wants to contribute to a healthy, free world with equal chances for everyone. With 'Je bent nodig' (You have a part to play), Radboud University aims to reach people who want to contribute to that goal. 

Would you like to actively contribute or read more about sustainability in our education and research? Visit www.jebentnodig.nl for more information.