Investigative Thursday: Hydrological Risky Cities Of The World

Introduction

Water is essential for life, but in many cities around the world, it has become a double-edged sword. From devastating floods to chronic water shortages, the hydrological risks associated with urbanization and climate change are increasing. This investigative piece delves into some of the most hydrologically risky cities globally, examining the factors that make them vulnerable, the impact on their populations, and the efforts being made to mitigate these risks.

1. Jakarta, Indonesia: A Sinking Megacity

Jakarta is one of the most hydrologically risky cities in the world. Located on the northwest coast of Java, this sprawling megacity is home to over 10 million people. However, it is sinking at an alarming rate, with some areas subsiding by as much as 25 centimeters per year. This phenomenon, largely driven by excessive groundwater extraction, has made Jakarta highly susceptible to flooding.

In 2020, a particularly severe flood displaced over 60,000 residents and caused at least 66 deaths. The situation is so dire that the Indonesian government has announced plans to relocate the capital to Borneo. According to a study by the World Bank, 40% of Jakarta is now below sea level, and if current trends continue, large parts of the city could be underwater by 2050.

2. Bangkok, Thailand: A City on the Brink

Like Jakarta, Bangkok is also sinking, though at a slightly slower rate of about 1-2 centimeters per year. The city is built on a low-lying floodplain, making it naturally prone to flooding. However, rapid urbanization, inadequate drainage systems, and climate change have exacerbated the situation.

The 2011 floods were a stark reminder of Bangkok's vulnerability. Heavy rainfall caused the Chao Phraya River to overflow, inundating large parts of the city. The disaster resulted in 813 deaths and economic losses of approximately $46 billion. Despite these challenges, the city's population continues to grow, increasing the pressure on its already strained water management systems.

3. Dhaka, Bangladesh: Battling Water on All Fronts

Dhaka, the capital of Bangladesh, faces a unique set of hydrological challenges. Situated in the delta of the Ganges, Brahmaputra, and Meghna rivers, the city is prone to both riverine and urban flooding. In addition, rising sea levels and the increased frequency of cyclones due to climate change have made the situation more precarious.

According to a report by the Intergovernmental Panel on Climate Change (IPCC), Dhaka is one of the most vulnerable cities in the world to climate change. In 2020, the city experienced one of its worst floods in recent history, affecting over 4 million people and causing significant damage to infrastructure. The World Bank estimates that by 2050, up to 13 million people in Bangladesh could be displaced by climate-related factors, with Dhaka being one of the hardest-hit areas.

4. New Orleans, USA: A City at the Mercy of the Sea

New Orleans is no stranger to hydrological risks. Located in a low-lying area near the Gulf of Mexico, much of the city is below sea level, making it highly vulnerable to storm surges and flooding. Hurricane Katrina in 2005 was a catastrophic event that exposed the city's vulnerabilities, leading to the deaths of over 1,800 people and causing $125 billion in damages.

Despite efforts to strengthen levees and improve flood defenses, New Orleans remains at high risk. A study by the U.S. Geological Survey found that the city is sinking at a rate of 1-2 centimeters per year, and rising sea levels could further exacerbate the situation. The National Oceanic and Atmospheric Administration (NOAA) warns that by 2050, sea levels could rise by up to 2 feet, increasing the likelihood of severe flooding events.

5. Mumbai, India: A City Facing Multiple Threats

Mumbai, India's financial capital, is another city grappling with hydrological risks. The city's coastal location and its dense population of over 20 million people make it highly susceptible to flooding. In addition to monsoon-related floods, Mumbai also faces the threat of rising sea levels.

The 2005 floods were a wake-up call for the city. A record-breaking 944 millimeters of rain fell in just 24 hours, leading to the deaths of over 1,000 people and causing widespread damage. According to a report by the McKinsey Global Institute, rising sea levels could threaten $100 billion worth of assets in Mumbai by 2050. The city's drainage system, which dates back to the British colonial era, is inadequate to cope with such extreme weather events, and significant investment is needed to upgrade the infrastructure.

6. Venice, Italy: A Sinking Heritage

Venice, the iconic city built on water, is facing a crisis as rising sea levels and subsidence threaten its very existence. The city has been sinking for centuries, but climate change has accelerated the process. According to a study published in the journal Quaternary International, Venice is sinking at a rate of 1-2 millimeters per year, and the surrounding Adriatic Sea is rising by 2 millimeters annually.

In November 2019, Venice experienced its worst flooding in over 50 years, with water levels reaching 1.87 meters above sea level. The flood caused an estimated €1 billion in damages and raised concerns about the city's future. The MOSE project, a series of flood barriers designed to protect Venice from high tides, has been delayed by technical issues and corruption scandals, leaving the city vulnerable.

7. Lagos, Nigeria: A City at Risk from Rising Seas

Lagos, Nigeria's bustling commercial capital, is one of the fastest-growing cities in Africa, but it faces significant hydrological risks. Situated on the Atlantic coast, Lagos is vulnerable to rising sea levels, coastal erosion, and flooding. With a population of over 24 million people, the city's infrastructure is already under immense pressure, and the impact of climate change are exacerbating the situation.

According to a report by the Nigerian Institute of Oceanography and Marine Research, parts of Lagos could be submerged by 2050 if sea levels continue to rise at their current rate. The city has experienced several severe floods in recent years, with the 2017 floods being particularly devastating, displacing thousands of people and causing widespread damage to property. The Lagos State government has initiated various projects, such as the Eko Atlantic City, a new city being built on reclaimed land, to mitigate the effects of rising sea levels, but these efforts may not be enough to protect the city's most vulnerable communities.

8. Cairo, Egypt: A City Threatened by Water Scarcity and Floods

Cairo, the capital of Egypt, faces a dual hydrological challenge: water scarcity and the threat of flooding. The city relies heavily on the Nile River for its water supply, but upstream developments and climate change are threatening this vital resource. The construction of the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile has raised concerns about reduced water flow to Egypt, which could exacerbate water scarcity in Cairo.

On the other hand, the city is also at risk of flooding from the Nile, particularly during periods of heavy rainfall. In 2020, Cairo experienced unusually heavy rains that caused significant flooding, leading to the deaths of at least 20 people and substantial damage to infrastructure. The Egyptian government has launched various initiatives to improve water management and flood defenses, but the city remains highly vulnerable to hydrological risks.

9. Accra, Ghana: A City Struggling with Floods and Coastal Erosion

Accra, the capital of Ghana, is another African city facing significant hydrological risks. The city's location along the Gulf of Guinea makes it vulnerable to coastal erosion, while rapid urbanization and inadequate drainage systems contribute to frequent flooding. The city's population has grown rapidly in recent years, putting additional strain on its infrastructure.

The 2015 floods in Accra were particularly devastating, with heavy rains causing widespread flooding that displaced thousands of people and resulted in the deaths of over 150 people. The floods were compounded by a fire at a petrol station, which led to further casualties. The Ghanaian government has since undertaken various measures to improve drainage and flood management in the city, but Accra remains at high risk, especially as climate change is expected to increase the frequency and intensity of extreme weather events.

Conclusion

The hydrological risks faced by cities around the world, including those in Africa, are a stark reminder of the challenges posed by climate change and unsustainable urbanization. From sinking cities like Jakarta and Venice to flood-prone cities like Lagos and Accra, the threats are diverse and multifaceted. While some cities are investing in infrastructure and disaster preparedness to mitigate these risks, the scale of the problem requires global cooperation and long-term planning. As the world continues to warm, the frequency and severity of hydrological disasters are likely to increase, making it imperative for cities to adapt to this new reality.

References

1.????? World Bank. (2021). Jakarta: A Sinking City. Retrieved from World Bank Website

2.????? IPCC. (2020). Climate Change and Water. Intergovernmental Panel on Climate Change.

3.????? McKinsey Global Institute. (2020). Climate Risk and Response in Asia.

4.????? U.S. Geological Survey. (2019). Subsidence in New Orleans.

5.????? Quaternary International. (2018). Subsidence and Sea-Level Rise in Venice.

6.????? NOAA. (2021). Sea Level Rise and Flooding in New Orleans. National Oceanic and Atmospheric Administration.

Nigerian Institute of Oceanography and Marine Research. (2021). *