Zhouqu County Mudslides

On the 8th August 2010, a mudslide occured in Zhouqu county, in southern Gansu province (Gannan Tibetan Autonomous Prefecture) in the PRC. The mudslide was 5km long and 300m wide, and up to 5m thick in places.

Causes

The mudslide was caused by a variety of factors, human and physical.

Forests around Zhouqu had been cut down for mining and agriculture which lead to soil erosion and destabilisation of the slopes, as roots were no longer holding the soil together and trees could no longer absorb water from the soil, leading to faster soil water saturation.  Despite the logging ban in 1998, trees continued to be felled. In the PRC, there had been 53 hydroelectric construction projects in recent years, with 12 just within Gansu province, where Zhouqu county is located. The dams have caused 750,000 tonnes of water and soil erosion and over 3 million cubic tonnes of bulldozed material, throughout the country. This has left the slopes weak and exposed to rainfall, allowing slides to occur more readily.

Oscillations between the patterns of El Nino and La Nina (climatic events where air currents across the Pacific Ocean change, effecting the local weather systems among dozens of countries) caused unusually intense monsoon rains in 2010.  Regions were receiving an extra 24 mm of rain above the normal daily rainfall. In ‘the largest downpour for a century’ 96 mm of rain fell in just one hour in the area.  The earthquake in Sichuan two years previously created cracks in the rock face and destabilised the ground; Zhouqu county is very close to Sichaun province, so instabilities within Sichaun can very easily effect towns within Gansu, directly to the North. The 9-month drought which preceded the heavy rain had added to the weakness and instability of the soil, especially when followed by the heavy rainfall.

Impacts

Social Impacts:

  • 1,471 people died due to the slide.
  • 1,200 people had to be rescued from the debris.
  • 300 people were never found, and are presumed dead.
  • 1,700 people who were evacuated from the immediate area were forced to live in schools. In total 45,000 people in Zhouqu county were evacuated.
  • Medical care in the region was disrupted as 10 doctors from the Zhouqu People’s Hospital were among the missing.

Economic Impacts:

  • 66% of the county went without power, disrupting local businesses and transport.
  • More than $40 billion worth of damage was caused in Gansu.
  • Power lines were down in 2/3 of the county which had to be repaired. Wider infrastructure was destroyed at great cost.
  • Mudslides throughout China in 2010 destroyed 8.76 million hectares of crops to be destroyed.
  •  The livelihoods of millions of people were entirely destroyed or otherwise decimated and China’s capacity to export was massively reduced.

Environmental Impacts:

  • 300 buildings were buried under mud.
  • A 3km temporary lake formed behind a blockage when the mudslide reached the local river at the base of the city of Zhouqu where the slide occured. This dam later burst causing further damage.
  • The river was clogged with debris, damaging habitats and reducing biodiversity.

Management 

  • 7,000 soldiers, firefighters and medical staff were deployed by the government. 20 speed boats and 4 helicopters were also mobilised.
  • Gansu province received 120 million yuan ($17.7 million) by August 13th 2010.
  • The PRC government promised local families $1,182 worth of financial aid for each victim lost.
  • Tents, food and medical supplies were rushed to the stricken area but the remote mountainous location made access difficult.
  • The governmentpromised to help rebuild homes and buildings in the affected area.
  • A National Day of mourning was observed to help with the emotional trauma.
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Sri Lanka Mudslides, 2016

Image result for sri lanka mudslide 2016

Mudslides hit Sri Lanka in May this year. Mudslides hit three villages in central Kegalle district. The landslide started near the town of Aranayake on the 17th May, 2016, but events leading up to it should have made the outcome predictable from the 15th onward.

Many cities were flooded with more than 100mm of rain on the 15th of May. International airports had to be closed just from the weather, and 35 families had been displaced. Airports would remain closed over the next few days.

Causes

3 days of torrential rain destabilised slope areas, in the heaviest rainfall in 25 years. The rain started on the 14th May.

Before the extreme weather, Sri Lanka had been experiencing a drought, and power cuts as hydroelectric power stations could not function. A rare benefit of the extreme weather which triggered the event was that the dams filled up to 75% capacity, allowing a supply of electricity to rescue workers to help them work effectively.

The main landslide area was very sparsely populated by only a few minor villages. No major work had been undergone on the slopes, as evidenced by footage of the event. Instead it was caused by a sudden huge increase in slope water content combined with susceptible rock type.

Impacts

On the 18th, 134 people remained unaccounted for, and 14 bodies had been recovered, with 37 deaths total. 350,000 people were displaced. 92 deaths have now been confirmed. 220 famlies were reported missing according to the Sri Lankan Red Cross. As of May 25th, the death toll was deemed to be 101 with 100 missing people.

The slide crashed into 3 separate villages; Elangapitiya, Pallebage and Siripura, all of which were obliterated.

60 houses were buried in dirt.

The mud level was up to 30ft deep in some areas.

Many sectors of infrastructure were effected, such as planes. Many major roads were entirely flooded, including the Southern Expressway. There were heavy power failures in some towns. The government warned members of industries such as fishing to not go to work until the situation was sorted- this was of course an attempt to save lives, but there was an economic impact because of this upon fishermen.

Response

The Meteorology Department of the government issued a severe weather warning on the 14th, for 12 hours. 100mm of rainfall was expected, with wind speeds of up to 80kmh in exposed areas.

One of the initial responses to the initial weather, was closing down air traffic.  Closed airports included: Bandaranaike International Airport (flights diverted to Cochin International Airport or Mattala Rajapaksa International Airport), and Ratmalana Airport. The Sri Lanka Airforce had to be called in to rescue stranded fishermen. The Navy had to save 200 people trapped in floods on the 17th, and the mud slides started, killing 21 in just one slide. The Airforce continued rescue work throughout using military grade helicopters. 81 Navy flood relief teams were dispatched.

Rescue teams were sent out to the area specifically, so that 156 people had been rescued by the 18th May, along with 1,550 people already sheltered in seven different evacuation sites. Soldiers were active in rescue efforts for weeks afterwards. Military spokesman Brigadier Jayanath Jayaweera said that the situation was being constantly assesed and that more troops would be deployed as needed, but that he doubted they would find many survivors.

More than 185,000 people who lost their homes were housed in temporary emergency shelters. The rain hindered the effectiveness of rescue efforts, in addition to causing the initial event. Many roads were underwater, and impassible, and national parks were completely closed off, and rescuers struggled to bring in their equipment. The Ceylon Electricity Board imposed emergency power cuts as a precautionary measure. In one night, the Army and Navy evacuated 26,000 people from Colombo (the capital). 1,500 armed personal were rallied,  including 71 officers.

All schools were closed on the 20th.

International efforts from other countries included:

  • Australia contributing $500,000 to UNICEF for humanitarian assistance
  • India pledging to provide assistance, and then bringing in Navy ships full of supplies.
  • Japan sent planes carrying emergency items, such as generators, blankets, and water purifiers.
  • Nepal offered $100,000
  • Pakistan gave a 30-bed field hospital
  • Singapore Red Cross donated $150,000 in relief items
  • United Nations- in collaboration with other NGOs- offered people to help administer aid
  • USofA provided $50,000 in immediate aid and a further $1 million in providing water for populations vulnerable to floods.

(Image Source: http://www.bbc.co.uk/news/world-asia-36328863)

France- Energy Mix

1973 Energy Mix

  • 40% coal
  • 17% oil
  • 19% gas
  • 5% nuclear
  • 6% HEP
  • 13% other renewables

2005 Energy Mix

  • 5% coal
  • 32% oil
  • 15% gas
  • 42% nuclear
  • 2% HEP
  • 4% other renewables

France imports 99% of its oil, largely from Norway and OPEC.

Coal was previously mined in the North East of France but  the difficulty of extracting new coal and the expense of accessing it caused the closure of the remaining coal mines at the beginning of the 21st century. The oil crisis of 1973 drove the creation of 59 nuclear power stations.

The need to comply to greenhouse gas emission regulations has led to a resurgence in interest in nuclear power, largely in replacing, not removing, old plants. Nearly 60,000 people work in the nuclear power plants. Their expertise has allowed the French company EDF to work internationally.

HEP power is concentrated in the alps and along the river Rhone. The Rhone produces 25% of France’s HEP, which is 5% of the country’s generated electricity overall.

There are plans to import electricity from Northern Africa. For instance, Algeria, a former French colony, has operational solar plants already.

France was an early pioneer of tidal power and built a tidal system across the river Rance, but have built no further commercial tidal energy projects.

Most oil used in France is used in transport or heating. HEP is used to back up the nuclear power supply at peak times.

India- Energy Mix

1973 Energy Mix

  • 61% renewables, including fuelwood
  • 22% coal
  • 15% oil
  • 2% HEP
  • 0% Gas
  • 0% Nuclear

2005 Energy Mix

  • 30% renewables, including fuelwood
  • 39% coal
  • 24% oil
  • 1% HEP
  • 5% Gas
  • 1% Nuclear

India’s energy consumption has increased by 300% since 1973. Population and demand for fuel have increased greatly, which has meant that India now has to rely on imports for its energy needs; particularly for more volatile regions of the world.

India’s own oil reserves are limited even as the country is becoming more oil reliant. India is training many engineers and is investing a lot of money in research and development of renewable fuels. With limited native resources, India is turning to nuclear power, and is reliant on Russian expertise to help manage its energy gap until technology, finances and infrastructure improve enough to support the use of renewable energy.

India is committed to researching and developing solar power sources. In March 2010, the World Bank invested US$20 million into developing further solar power stations such as the 2MW plant by India’s Azure Group. India plans to generate 20MW of solar power by 2020.

India has also built several dams:

Narmada Mega Dam Scheme

The scheme consists of 3,200 major, 135 medium and more than 3,000 smaller dams. The largest is the Sardar Saravar dam. The dam supplies water for agriculture, HEP and drinking water for 20 million people. Howver, it is mostly a vanity project; the same result could have been achieved with far smaller projects.

Three Gorges Dam

(This graphic on its own does a good summary)

The Three Gorges Dam is the largest Hydroelectric Power scheme. The dam blocks the 3rd largest river in the world, the Yangtze.400 million people live in it’s drainage basin.

Reservoir can flood up to 1045 km^2 at peak capacity. 1200 villages have been disappearing since 2002. 1500 factories and 70 waste management plants have had to close or move.

Of the more than a million relocated people, there have been numerous complaints:

  • Inadequate compensation
  • Reduction in land quality- the government recompensated with giving new, lower quality land
  • Widespread fraud and corruption among officials
  • 1,000s forced to live in squalid conditions.

Environmentally the dam has also had a huge impact:

  • Pollutants are leaked into the water flow
  • Water is too slow to remove these pollutants
  • This has caused algal blooms and eutrophication (a process in which life within an aquatic environment starts to slowly die out due to light being prevented from reaching the plants)
  • The dam traps sediment, causing deposition in the reservoir
  • River is sediment free downstream. This has changed the ecology and caused habitat loss.
  • Erosion has increased
  • The dam is thought to be responsible for the extinction of the Yangtze river dolphin (That said, it’s unknown if they are actually extinct. Either way, it has not helped their population.)
  • Loss of wildlife
  • 91 shoreline collapses
  • increased mud slides

Social and cultural impacts include:

  • 100s of cultural, archaeological and historical sits destroyed by the water
  • 600 km long reservoir destroying the natural beauty and character of the area.

Economically, the area has been affected by:

  • the loss of 30,000 hectares of farm land
  • sediment trapped by the dam has meant that there is less alluvial soil downstream, and farmers have naturally less fertile land, having to buy fertilisers for their fields.
  • East China Sea has suffered reduction in sediment, affecting habitats there (and so fish stocks)
  • Fish catches have fallen by 10 ^6 tons annually
  • Flooding has caused a permanent loss of coal and metal mines

All of this said, the Three Gorges Dam is better for the PRC than the coal power stations that would otherwise be needed to produce the same amount of energy.

(Image sources: https://geognis.edublogs.org/dp-geography/the-ib-five/china/chinas-three-gorges-dam/ http://www.yangziexplorer.org/destination/three-gorges-dam.html )