This month, a storm in Dubai drenched the city with a year and a half’s worth of rain in a single day. The excessive rain overwhelmed the streets, causing flooding that resulted in millions of pounds in property damage, and the loss of a life. The flooding has raised questions regarding flood defences in cities like Dubai. So what role does rapid urbanisation play in flooding? In these situations, which flood defence tools can help?
Over the past 40 years, Dubai has developed at a breakneck pace. Expansive construction and innovative design have led to some of the most famous buildings in the world. There is a downside to this rapid growth, however. Here are a few ways rapid development affects the water table and flooding in cities:
Source: The Guardian
1. Impact of Rapid Urbanisation:
As cities grow, natural landscapes are replaced with concrete, tarmac, and treated wood. These impermeable materials stop rain from being draining into the ground. This change overwhelms city drains, increasing standing water on roads and pathways. This can mean more puddles during light rain, but heavy rainfall leads to flooding and extensive property damage.
2. Runoff Water and Flood Risk:
With land covered in asphalt and tarmac, absorbent land is drastically reduced. Impervious urban landscapes exacerbate the flood risk, causing rapid accumulation of runoff water. This excess water saturates exposed ground, resulting in flash floods and waterlogged communities.
Unpredictable weather is an effect of climate change that we must prepare for in the coming years. With this in mind, how can cities protect themselves from the same flooding we’ve seen in Dubai?
Flood Defence Measures
Implementing targeted flood defence measures is critical to mitigate the impact of flooding in urban areas. Dubai’s desert location leaves them without effective drainage routes, so what could have helped in the short term?
Damming measures
Erecting flood barriers along critical drainage pathways to control water flow and prevent inundation of vulnerable areas. Boxwalls can create a temporary barrier across roads, with a damming ability of up to 50cm.
Absorption Measures
The most basic measure is traditional sandbags, but alternatives are available, like flood cubes or Osmo flood barriers. These are made with absorbent materials or permeable barriers to manage excess water and reduce surface runoff.
Importance of Sustainable Urban Planning
For a longer-term flood defence strategy, sustainable urban planning practices play a pivotal role in flood risk reduction. Preserving any natural drainage features like wetlands and integrating green infrastructure, such as bioswales and green roofs, can help restore the water-retaining capacity of urban environments.
Integrated Solutions for Resilience:
Addressing flood risks requires a holistic approach that combines engineering solutions with environmental considerations. This includes implementing regulations that promote flood-conscious development practices and retrofitting existing infrastructure to enhance flood resilience.
Dubai’s recent challenges serve as a sobering reminder of the urgent need to prioritise flood defences in the face of rapid urbanisation. Through innovative flood management strategies and integrating sustainability into urban development, cities can mitigate the impact of climate change and ensure the safety and well-being of their inhabitants.
In conclusion, proactive investment in flood defence measures is essential for safeguarding rapidly urbanising regions from the escalating threats of flooding. By learning from Dubai’s experiences and adopting tailored flood management strategies, cities worldwide can build resilience, preserve natural ecosystems, and create livable environments resilient to the challenges posed by urban expansion and climate change.
