The flooding that happened in Libya this weekend has left thousands dead and missing. What is known about this disaster at this point? Why do floods happen in the first place? Which countries are most prone to them, and why? And what should you do if you find yourself at the epicenter of such a disaster? We tell you in our material.

What is known about the flooding in Libya?

Here is the main thing that is known about the flooding at the moment:

  • Catastrophic flooding in Libya was caused by Storm Daniel, which hit the region on Saturday, September 9, 2023. Heavy rains and flooding breached levees and caused widespread destruction. Floodwaters peaked in northeastern Libya on Sunday, with strong winds reaching 80 kilometers per hour.
  • The city of Derna in northeastern Libya was the most affected. Floodwaters swept away several large bridges and collapsed many of the city's high-rise buildings located on the banks of the riverbed.
  • Satellite images show that entire neighborhoods were washed away and many bodies were swept out to sea.
  • The death toll has surpassed 6,000, with at least 10,000 people missing.
  • Many hospitals in Derna were demolished, and morgues were overcrowded.
  • Other areas close to Derna, including the town of Al Bayda, have also been severely affected.

WHO has placed humanitarian aid in the affected areas. It estimates that up to 1.8 million people have been affected by the torrential rain and that some hospitals have been damaged and even “wiped out”. The Libyan Government has declared three days of mourning in all affected cities.


Why do floods happen?

Floods can occur for a variety of reasons; here are some of the main ones:

  • Heavy rainfall: One of the most common causes of flooding is heavy or prolonged rainfall. When more precipitation falls than the ground can absorb or rivers and streams can carry, it causes water to spill onto the topography.
  • Snowmelt: In regions with cold winters, snowmelt in the spring can lead to flooding. If the snow melts too quickly or there is a sudden warming, it can overflow rivers and cause them to flood.
  • Storm surges: Coastal areas are prone to flooding from storm surges that occur during hurricanes, typhoons, and tropical storms. These storms can push large volumes of water inland, causing flooding in coastal areas.
  • Flash floods: Flash floods are often the result of intense rainfall over a short period of time. They can occur in areas with steep terrain, in cities with poor drainage systems, or near forest fires that have stripped the landscape of vegetation.
  • Ice jams: In cold climates, ice can build up on rivers, forming ice jams. These jams can block the flow of water, causing it to overflow and flooding nearby areas when the jam eventually breaks.
  • Human activities: Human activities can contribute to flooding. Deforestation, urbanization, and the alteration of natural drainage systems can increase flood risk by reducing the land's ability to absorb and drain excess water.
  • Dam or levee failure: Floods can occur when man-made structures such as dams and levees fail. If these structures are not properly maintained or are overwhelmed by a large volume of water, they can crack, resulting in catastrophic flooding downstream.
  • Climate change: Climate change can exacerbate flooding by altering weather patterns and increasing the frequency and intensity of extreme weather events such as heavy rainfall and storms.

Which countries in the world are most prone to flooding?

It is difficult to rank the most flood-prone countries unambiguously, as floods can occur in different forms (river, coastal, and flash floods) and with different frequencies. However, it is known that some countries are particularly prone to flooding due to their geographical and climatic characteristics. 

Some of these countries include:

  • Bangladesh is known as one of the world's most flood-prone countries. This South Asian country experiences frequent and severe flooding due to its unique geographical location and monsoon climate. Bangladesh is crossed by numerous rivers, including the Ganges and Brahmaputra, which carry water from the Himalayas. During the monsoon season, heavy rainfall in the region, coupled with snowmelt in the mountains, results in significant amounts of water flowing into these rivers.
  • India: Some parts of India, especially in the Ganges and Brahmaputra basins and on the east and west coasts, are prone to flooding during the monsoon season and as a result of cyclonic activity.
  • Vietnam: Vietnam is prone to frequent river and coastal flooding, especially in the Mekong Delta region, due to heavy rainfall, typhoons, and sea level rise.
  • Indonesia: The nature of Indonesia makes it prone to both riverine and coastal flooding. Flooding is particularly common in the capital city of Jakarta.
  • China: China is prone to riverine and flash flooding, often caused by heavy rainfall and snowmelt, especially in areas near the Yangtze River, the Yellow River, and in southern provinces.
  • Pakistan: Pakistan is prone to river flooding, especially in areas near the Indus River, due to heavy monsoon rains and snowmelt.
  • Philippines: The Philippines is prone to both coastal flooding associated with typhoons and flash floods caused by heavy rains during the wet season.
  • Nepal: Nepal is at risk of river flooding, mainly due to its mountainous terrain and heavy monsoon rains.
  • USA (particularly areas along the Mississippi and Missouri Rivers): The United States is experiencing significant riverine flooding, particularly in areas along the Mississippi and Missouri Rivers, caused by heavy rainfall, snowmelt, and dam failure.

Note that Libya is not generally considered to be at high risk of flooding, primarily because it has a dry desert climate with low average annual rainfall. Most of Libya is covered by the Sahara Desert, which is one of the driest and hottest regions in the world. As a result, the country experiences arid and semi-arid conditions with infrequent and minimal rainfall in most areas.
However, it is important to note that Libya, like many arid regions, experiences flash floods from time to time. The risk of their occurrence is increased:

  • Sporadic rainfall: Although Libya is largely arid, there are areas along the Mediterranean coast and in the northern part of the country where rainfall is irregular, especially during the winter months. Heavy rainfall in these areas can lead to flash floods, as the dry desert soil is unable to absorb water quickly.
  • Poor drainage infrastructure: In some urban areas, poor drainage systems can exacerbate the effects of heavy rainfall, leading to localized flooding.
  • Topography: The terrain in some areas of Libya, such as the Jebel Akhdar area, can lead to flash flooding when heavy rains flow down steep slopes into valleys.

People walk near houses affected by flooding in Derna, Libya

The most catastrophic flood in world history

One of the most catastrophic floods in world history was the 1931 flood in China. A vast area of China was affected, with the Yangtze River basin and the Huai River basin being the worst affected.


  • Heavy rains: the flood was caused by a number of factors, including prolonged and heavy monsoon rains.
  • Snowmelt: Snowmelt in the mountains, especially on the Tibetan plateau, increased the volume of water entering the rivers.
  • River flooding: The Yangtze River, China's longest river, and its tributaries, including the Yellow River, overflowed their banks.


  • Estimates of the death toll from the 1931 flood in China vary widely, but it is believed that between 1 and 4 million people died. This variation in estimates is due to difficulties in accurately documenting casualties during and after the flood.
  • Millions of people were displaced from their homes, and entire villages and towns were inundated. The flooding caused immense suffering, including hunger and disease among survivors.
  • Floods inundated vast agricultural areas, leading to crop failure and food shortages.
  • Housing, infrastructure, and transportation networks were severely damaged or destroyed.

What actions should you take if you are in a flood zone?

If you find yourself in a flood zone, here are the most important things to know:

  • If local authorities have issued an evacuation order, follow it immediately.
  • If you are unable to evacuate and are trapped in a building, go to the highest level or top floor. Take your necessary belongings and documents with you.
  • Do not walk, swim, or drive a vehicle through floodwaters. Remember that as little as six inches of moving water can knock you down, and one foot of moving water can carry your vehicle away.
  • Stay out of floodwaters, as they can be contaminated with sewage, chemicals, or debris.
  • Watch for weather updates from local authorities, weather services, or news outlets. Pay attention to flood alerts and warnings.
  • Stay in your vehicle if it is trapped in fast-moving water. Get out on the roof if water is rising inside the vehicle.
  • Do not return to a flood-affected area until local authorities declare it safe to do so. Flooding may persist even after the rain has stopped.

Cover photo by Jamal Alkomaty/AP