Floods! Huge waves crash toward you, not caring if it is a forest, bare land, or a well-established urban colony. Floods are a terrifying natural calamity the world could go through. Causing loss of family, homes, documents, and hope.
According to statistics, a small flood occurs once every two years, and a moderate flood once every five years. A massive surge is predicted to occur only once in fifty or a hundred years.
But this same year, the world has seen several scarring floods, affecting thousands of people. Why are so many parts of the world facing such severe floods all at once? These floods are to be called “Urban Floods.”
What are Urban Floods?
Urban Floods have more to them than “water overflow in urban areas.” With the significant growth in urbanization and urban living plans and spaces, flood risks have increased by 1.8 to 8 times. The reason is the excessive water logging caused by developed areas. The excess water has nowhere to go. The water is then clogged and blocked in drains and sewage systems with no proper cleaning and channeling system.
The clogged water is bound to overflow with the smallest amount of rain, which can lead to disastrous events like floods and hurricanes. The inadequate infrastructure seen in most urban neighborhoods is a threat to every person residing in these areas. Half of the lakes have vanished over the past few decades thanks to reclamation for real estate. Up to three-fourths of all lakes in the urban district are destroyed by illegal encroachments. These water bodies are significant catchment sites for incoming rainfall, making this a huge problem.
Bengaluru Floods, 2022
India’s IT hub is always affected every year due to floods triggered by rains. Bengaluru received around 18 cm of rainfall and even more in other areas. Thunderstorms and heavy rains occur in a shear zone encompassing southern Karnataka. The opposing wind flow brings heavy rain-bearing clouds to the zone.
The floods hit the city of Bengaluru on August 30th. The rains were so heavy, people were stuck in traffic in the busier areas of the city for over five hours. Companies suffered huge losses due to poor administration in the city.
- The crisscross drainage system of Bengaluru is old and decayed at this point. When an infrastructure in such condition receives 18 cm of rainfall, it exceeds its capacity to channel water, clogging, and floods.
- The waste generated after construction and demolition is often dumped in rivers and lakes, which causes the lakes to lose their connectivity to bigger water bodies.
- Urbanization in an unplanned and impulsive manner leaves the city with increased paved surfaces. Around 78% area in the city is paved. Urbanization has led to serious environmental degradation. Vegetation depletion can further lead to soil erosion.
California Floods, 2022
Strong winds and flooding rains struck southern California, causing flash floods that spread to sections of western Arizona. Winds as high as 109 mph made trees and power lines fall. California is also warned of more flooding, heavy rains, and flooding in the next weeks. The state is already prone to catastrophic “mega-fires” that destroy acres of vegetation and towns.
- Urbanization has led to the cutting of thousands of trees in the California region. That land is where they construct the urban and suburban colonies of California.
- Urbanization has resulted in up to 1.4 K decreases in daytime air temperature and up to 1.7 K rises in nighttime air temperature.
Africa Floods, 2022
Floods hit Africa earlier this year in April. The calamity caused the death of 400 people and displaced more than 40,000 people. 12,000 houses were destroyed in the southeast part of South Africa.
Through flood hazard maps, it was seen that the houses were in proximity to waterways/rivers.
- Construction of living spaces near canals without following building codes set by urban planners leads to more such damages in flood-like situations.
- The uncontrolled release of dams for construction and other urban purposes right before high rainfall contributed to the occurrence of floods.
Networks and organizations are working towards helping cities and regions identify, plan and implement projects to increase resilience to urban flooding impact.
- Governance and holistic water management
Encouraging public involvement and participation in a complete and integrated water management plan to control urban flooding.
- Measuring and monitoring urban flooding
Supporting and assisting cities affected by urban floods is as essential—faster actions with measures like rescue operations and response strategies.
- Flood reduction
Promoting the sustainable drainage, storage, entry, return, and integration of water in urban ecosystems to help cities prepare for floods (blue-green infrastructure).