Behind Libya’s Catastrophic Flooding: Extreme Weather, Vulnerable Geography, And Crumbling Infrastructure

Relevance: GS1 - Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., GS3 - Disaster and disaster management

(Source: Indian Express, 09/14/2023)

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Why in the news?

Recently, flooding caused by Storm Daniel resulted in the collapse of two dams and four bridges and the death of around 5,000 people in Derna in eastern Libya.

Impact of Storm Daniel

• The Mediterranean storm Daniel has caused devastating flash floods impacting large parts of Libya in North Africa.
  • Daniel was formed in Greece and caused floods and deaths in Spain, Turkey, and Bulgaria in September.
• Daniel deposited 440 millimeters (15.7 inches) of rain on east Libya in a short span, possibly overwhelming the country’s infrastructure and causing the failure of the dam.
• As a result of the storm and consequent flash floods, two dams and four bridges in Derna collapsed.
• According to city officials of Derna, the floods have resulted in the destruction of at least 20% of the city.
• The Red Crescent claimed that around 10,000 people have been reported missing.
• More than 30,000 people have been displaced as a result of the flooding with experts claiming that the death toll may double.

Relief work

• The US, Germany, Iran, Italy, Qatar, and Turkey have already promised or supplied aid.
• However, relief work in Libya is likely to be impacted by the Civil war between the Tripoli-based government and the east Libyan government controlled by military leader, Khalifa Hifter.
  • Hifter is also backed by Egypt, Russia, Jordan, and the United Arab Emirates, while the West Libya administration is backed by Turkey, Qatar, and Italy.
• The Tripoli-based government has dispatched 14 tons of medical supplies and $412 million for reconstruction in the region while Egypt is coordinating with the Hifter regime to provide aid.

What are the main factors behind the damage?

Extreme weather

• According to the WMO, Derna received more than 150 mm of rainfall between September 10-11, where average monthly rainfall for September is less than 1.5 mm.
• The rains were accompanied by strong winds of up to 80 kph, both of which were produced by Storm Daniel.

Vulnerable geography

• Derna, which was the worst affected city in Libya is a coastal city with around 100,000 inhabitants.
• Derna is situated at the end of a valley and is bisected by the Wadi Derna, a seasonal river that flows from mountains to the sea in the south.
  • The city is normally protected from flooding by dams.
• However, the dams outside the city collapsed during the storm resulting in flash floods down Wadi Derna.
• Derna has two dams - one about 12 km upstream from the city where two river valleys converge and another on the southern edge of the city.
  • The floodwater breached the two dams and entered the city causing widespread destruction.

Crumbling infrastructure

• As a result of the civil war in the country, there has been a lack of focus on the socio-economic development of the country including the proper development and maintenance of critical infrastructure.
  • This is evidenced in the collapse of the two dams in Derna.
• Dams, desalination plants, electrical grids, and roads have not been repaired or properly maintained.

What are Medicanes?

• Medicanes are extra-tropical hurricanes that are observed over the Mediterranean Sea.
  • They are similar to hurricanes and have a central eye-like structure, which is the strongest part of the storm.
• Formation:
  • Medicanes have been observed to form even at water temperatures of 15°C while normal hurricanes need temperatures of around 26°C to occur.
  • They usually form between September and December.
• Impact of La Nina on formation:
  • La Nina is characterized by the unusual cooling of the central and east-central equatorial Pacific Ocean.
  • It produces more rain in the central-eastern part, where most of the Mediterranean cyclones develop.
• Characteristics:
  • Medicanes occur more in colder waters than tropical cyclones, hurricanes, and typhoons.
  • They have colder cores when compared to the warm cores of tropical cyclones.
  • Therefore, tropical cyclones carry more moisture, are bigger in size, and have swifter winds.
  • Destructive winds are not the major threat to life and property during a Medicane but heavy rains and flash floods are.
  • Medicanes rarely achieve Category 1 hurricane strength (119 Kmph).
• Impact of climate change:
  • Climate change is expected to make Medicanes less frequent but more stronger whenever they take place.
  • The frequency of Medicanes will reduce as a result of global warming, as they are formed in cooler temperatures.

Why was Daniel more intense than other Medicanes?

• Storm Daniel became stronger as it drew energy from the abnormally warm waters of the Mediterranean Sea.
• In 2023, the Mediterranean Sea has been 2-3°C warmer than in previous years.
• Medicanes are generally weak storms that occur for short periods but the rise in sea surface temperatures due to global warming has made medicanes (and other storms) stronger and longer-lasting.
• This is because storms accumulate greater amounts of water vapor and heat as they travel across warmer oceans.
• This results in more powerful winds, heavier rainfall and more flooding when they make landfall.
• Human-induced increases in water surface temperatures are likely to have intensified the effect of Storm Daniel.
• The storm drifted to the south and resulted in excessive rainfall in the mountainous terrain in northeastern Libya.

Flash floods

• Flash Floods are sudden surges in water levels during or after an intense spell of rain.
• They are highly localized events with short duration and very high peaks.
• There are usually less than six hours between the occurrence of the rainfall and peak flood when a flash flood occurs.
• They differ from river floods in terms of the scale of the event and the short time scales.
  • This makes forecasting flash floods much more difficult than predicting traditional floods using conventional forecasting approaches.
• Flash floods are most likely to occur in urban areas as there are numerous hard surfaces in urban settlements that prevent rainwater from seeping into the ground.

Causes

• Flash floods are common in arid places that have just received precipitation, and areas close to volcanoes.
• Heavy rain caused by hurricanes, tropical storms, or the melting of ice dams can lead to flash floods.
• They can also be caused by human activity, such as dam discharge.

Effects

• It impacts the natural environment including vegetation, agriculture, geomorphology, and pollution.
• It causes humans to be trapped, injured, and killed when flash floods take place.
• It causes structural damage to bridges and roadways and makes travel impossible.
• Power, telephone, and cable lines are destroyed making communication difficult.
• It can contaminate groundwater and disrupt supplies, making tap water unfit for consumption.

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FAQs

MCQs

Question: La Nina is suspected to have caused recent floods in Australia. How is La Nina different from El Nino?

1. La Nina is characterized by unusually cold ocean temperatures in the equatorial Indian Ocean whereas El Nino is characterized by unusually warm ocean temperatures in the equatorial Pacific Ocean.
2. El Nino has an adverse effect on the southwest monsoon of India, but La Nina has no effect on the monsoon climate.

Which of the statements given above is/are correct? (UPSC CSE 2011)

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Question: Which one of the following countries of South-West Asia does not open out to the Mediterranean Sea?

(a) Syria

(b) Jordan

(c) Lebanon

(d) Israel

Question: Consider the following statements:

1. Jet streams occur in the Northern Hemisphere only.
2. Only some cyclones develop an eye.
3. The temperature inside the eye of a cyclone is nearly 10°C less than that of the surroundings.

Which of the statements given above is/are correct? (UPSC CSE 2020)

(a) 1 only

(b) 2 and 3 only

(c) 2 only

(d) 1 and 3 only