• Thousands of people were killed and at least 10,000 were missing in Libya in floods caused by a huge Mediterranean storm that burst dams, swept away buildings and wiped out as much as a quarter of the eastern coastal city of Derna.
• Extreme rainfall from Storm Daniel has hit parts of the central and eastern Mediterranean, leading to devastating flooding and loss of life in Libya, the worst affected country, as well as in Greece, Turkey and Bulgaria.
• Emergency workers uncovered more than 1,500 bodies in the wreckage of Libya’s eastern city of Derna following the massive floods triggered by Storm Daniel.
• It was feared the death toll could spiral with 10,000 people reported still missing after floodwaters smashed through dams and washed away entire neighbourhoods of the city.
• Entire neighbourhoods in Derna disappeared, along with their residents swept away by water after two ageing dams collapsed making the situation catastrophic and out of control.
• Storm Daniel developed in Greece and was named by the Hellenic National Meteorological Service. As it moved towards Libya, Storm Daniel developed the characteristics of a Medicane — MEDIterranean hurriCANE. This hybrid phenomenon shows some characteristics of a tropical cyclone and others of a mid-latitude storm.
• The floodwaters reached a peak in northeastern Libya, with strong winds of up to 80 kilometres per hour, interrupting communications and bringing down electricity towers and trees.
• Torrential rains of between 150-240 mm caused flash floods in several cities, including Al-Bayda in Libya, which recorded the highest daily rainfall rate of 414.1 mm
What are flash floods?
Floods occur within six hours, mainly due to heavy rainfall associated with towering cumulus clouds, thunderstorms, tropical cyclones or during passage of cold weather fronts, or by dam failure or other river obstruction. They can occur within minutes or a few hours of excessive rainfall. Flash floods occur due to high rate of water flow as also due to poor permeability of the soil. Areas with hardpan just below the surface of the soil are more prone to floods as water fails to seep down to the deeper layers.
Over 17,000 people died in floods and heavy rains between 2012 and 2021 in India. The increased incidence of high intensity rainfall of short duration is mainly responsible for urban floods, which is further compounded by unplanned growth, encroachment of natural water bodies and poor drainage system.