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SUMMARY OF LECTURE GIVEN BY PROF. R.B. SINGH (VICE PRESIDENT, INTERNATIONAL GEOGRAPHICAL UNION) ON CLOUD BURST AND ITS REASON ALONG WITH SEVERAL CASE STUDIES IN DELHI SCHOOL OF ECONOMICS....

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CLOUD BURST 1.0 INTRODUCTION Cloud burst is known to be a different than rainfall only in terms of water that pours down the earth. It is define as an extreme amount of precipitation in a short period of time, sometimes accompanied by hail storm and thunder and is characterized by flash floods and landslides. Indian meteorological department define cloud burst as more than 100mm/h precipitation over geographical region of approximately 20-30 km square. The geography of a place makes it vulnerable to cloudbursts. The Himalayan region especially the western Himalayas is known to be the most vulnerable to cloudbursts as it provide suitable conditions for the formation of cloudbursts. Most of the cloudburst events are seen occurring in the elevation range of 1000m to 2500m within the valley folds of the southern rim of the Indian Himalayas.

1.1 Why and how does it happen? Cloudbursts occurs because the warm air currents from the ground rushes up and carries the falling raindrop with it. The rain fails to fall down in steady shower. The rain fails to fall down in a steady shower. This results in excessive condensation in the clouds as new drops form and old drops are pushed back into it by the updraft. Then one of them gives in. The air current slows down or the clouds can't hold. The resulting violent downpour can dump as much as 70,000 tonnes of water over an acre of land. In India, a cloudburst mostly occurs in the mountains of India where the low monsoon clouds are stopped by the high mountains.

Western Himalayan region provide best suitable conditions for cloudbursts as the air that moves upwards is warm and has moisture which it collects from the agricultural fields form the plains and is it moves to the high latitudes where the temperatures are low results in the sudden condensation (due to nominal change in the temperature) which creates clouds results in heavy rainfall. This region faces great loss as huge amount soil comes down along with boulders and debris in the form of landslides and the agricultural field in foothills of the mountains are completely destroyed thereby the area faces great loss of lives wealth and economy and ecology are worst affected. The best example of this is of 2013 flash floods that happen because of cloudbursts in Uttarakhand, wherein 4 districts, Rudrapryag, Chamoli, Uttarkashi and Pithoragarh were worst affected. It is further discussed in detail.

2.0 DISTRIBUTION OF CLOUD BURST In the recent decades vagaries associated with ‘cloudburst’ events are frequently reported in and around the southern rim of the Indian Himalayas. Most of these cases are associated with unexpected heavy precipitation. The Himalayan orography with its steep and unstable inclines forms a perfect platform for such a cloudburst event to lead to flash floods or landslides. Predicting the location, amplitude and magnitude of such catastrophic events in

advance remains a challenge. A cloudburst is an intense torrential rainfall brought by a thunderstorm that lasts for a relatively short duration (few minutes to few hours).Cloudburst leads to flash floods and causes lot of damage to life and property .Every intense rainfall is not a Cloudburst. Cloudburst specifically occurs when an air mass with high humidity is struck at a place due to various reasons. 2.1 Cloud Burst In Western Himalayas (Jammu & Kashmir, Uttarakhand And Himachal Pradesh) A cloudburst is an intense torrential rainfall brought by a thunderstorm that lasts for a relatively short duration (few minutes to few hours).Cloudburst leads to flash floods and causes lot of damage to life and property. Every intense rainfall is not a Cloudburst. Cloudburst specifically occurs when an air mass with high humidity is struck at a place due to various reasons. In 2010, South-Western strip of Russia (Caucasus Region, Moscow etc.) saw higher than normal temperatures (highest in in the last 100 years) and there were numerous cloudbursts in Jammu and Kashmir. A strong upper-atmospheric high was located over European Russia towards the beginning of summer. It diverted the jet stream (meandering of Sub-Tropical Jet Stream) and its rain-giving train (trough) of summer storms farther north than usual, giving much of Southern European Russia drought conditions. In addition, southern desert heat from central Asia, the Arabian Peninsula and North Africa began to flow northward, which then stalled system prevented weather systems being drawn across Russia and the obstacle acted as a barrier trapping hot air to the south and cold air to the north. The consequence of this static mass of hot air was the heat wave that devastated Russia. With the jet stream stalled the Sub-Tropical Jet was unable to transit across the Himalayas as it would do ordinarily, the monsoon cell to the south, fed by warmer waters in the Indian Ocean, had nowhere to go and as a consequence it deposited vast amounts of rain over Pakistan, Himachal Pradesh and Jammu and Kashmir and this led to extensive flooding. 2.2 Cloud Burst In Central Himalayas (Nepal) Cloudbursts in Nepal normally occur late at night or early morning. A cloudburst on July 1920, 1993 in the central Nepal was the most catastrophic cloudburst event in recorded history.

This event dropped 540mm/day with maximum intensity of 65mm/hr. This total daily rainfall was almost half of the total for the monsoon season and approximately 5400% of the mean daily active monsoon rainfall in this location in Nepal This single event claimed about 1300 lives and left a devastating economic impact in central Nepal. Recently, another major cloudburst on August 5-6, 2010 in the West Indian Himalayas claimed 255 lives. Typically, these events tend to but not always occur during the monsoon break phase in India, suggesting a critical shift of the usual monsoon flow pattern that gives rise to the cloudburst events. 2.3 Cloud Burst In Eastern Himalayas Over the eastern Himalayas also during the monsoon there are various cloud burst events occur but the number of cloud burst in comparison the western Himalayas are less. Major events of cloud burst: o

In July, 1970 — Cloudburst in the upper catchment area led to a 15 meter rise in the Alaknanda River in Uttarakhand. Entire river basin, from Hanumanchatti near the pilgrimage town of Badrinath to Haridwar was affected. An entire village was swept away.

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On August 15, 1997, 115 people were killed when a cloud burst came bustling and trail of death are all that is left behind in Chirgaon in Shimla district, Himachal Pradesh.

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On August 17, 1998 — a massive landslide following heavy rain and a cloudburst at Malpa village killed 250 people including 60 Kailash Mansarovar pilgrims in Kali valley of the Kumaon division, Uttarakhand. Among the dead was Odissi dancer Protima Bedi.

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On July 16, 2003, About 40 persons were killed in flash floods caused by a cloudburst at Shilagarh in Gursa area of Kullu, Himachal Pradesh.

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On July 6, 2004, At least 17 people were killed and 28 injured when three vehicles were swept into the Alaknanda River by heavy landslides triggered by a cloudburst that left nearly 5,000 pilgrims stranded near Badrinath shrine area in Chamoli district, Uttarakhand.

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On 26 July 2005, a cloudburst caused approximately 950 millimetres (37 in) of rainfall in Mumbai. Over a span of eight to ten hours; the deluge completely paralysed India's largest city and financial centre.

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On August 16, 2007, 52 people were confirmed dead when a severe cloud burst occurred in Bhavi village in Ghanvi, Himachal Pradesh.

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On August 7, 2009, 38 people were killed in a landslide resulting from a cloudburst in Nachni area near Munsiyari in Pithoragarh district of Uttarakhand.

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On August 6, 2010, in Leh, a series of cloudbursts left 179 persons dead and over 400 injured in the frontier Leh town of Ladakh region in Jammu and Kashmir.

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On June 9, 2011, near Jammu, a cloudbursts left 4 persons dead and over several injured in Doda-Batote highway, 135kms from Jammu.Two restaurants and many shops were washed away

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On September 6, 2014 there was a cloudburst in Kashmir valley killing more than 200 people. Center for Science and Environment (CSE) mentioned heavy and unchecked development aggravated the development in the region. Over 1,84,000 people were rescued after heavy rains have large part of the State submerged. Indian Army and Central government provided necessary help in a very short span of time saving lives of many

3.0 REASONS FOR CLOUD BURSTING The convective weather situation is the most favourable condition for the agglomeration of clouds, thus leading to heavy weight and sudden intense, concentrated rainfall followed by flash floods. India is surrounded by water bodies from three sides and hence it is more prone to the convective weather situation. This small scale phenomenon is generally followed by thunderstorms whereby the moisture laden winds are forcibly raised upwards and the water vapour condenses and sudden downpour occurs due to heavy weight of the clouds. Intense vortices created during the triggering weather conditions lead to the generation of the strong convection currents which so forcibly lifts the moisture carrying winds that it takes form of cumulonimbus clouds. These clouds pour water intensively and the convective uprising air currents of the thunderstorm support large amount of water in the form of raindrops. The other factors which affect the process of cloud bursting include the temperature variations, altitudinal variation, vegetation cover, etc.

4.0 PATTERNS OF CLOUD BURSTING

Cloud bursting is not a locational phenomenon. It can occur anywhere provided the atmospheric situations develop in that way. However, generally it is seen that it occurs mostly in mountainous regions, deserts etc. 4.1 Pattern of Cloud Bursting in the Himalayas It has been observed that cloud bursting is a common phenomenon in the Western Himalayas than in the Eastern Himalayas. Following are the reasons for such differences in the occurrence of this hazard in the spatial context of the Himalayaso

The isohyets decrease from Eastern Himalayas to Western Himalayas. Average rainfall recorded in the Eastern Himalayas is about 200 cm while the later records about 100 cm. The sudden intensive downpour for few hours is observed in the Western Himalayas while continuous heavy rainfall occurs in the Eastern Himalayas. This continuous, longer spanned downpour is not a cloudburst.

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In the Western Himalayas, which have extensive anticlines and synclines, temperature in the summers in valleys reaches about 18 degree Celsius which lowers to as low as 5 degree Celsius at higher altitudes.

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The warms winds ascend the slope as they are affected by the lapse rate, surrounding weather phenomenon which leads to sudden condensation and sudden downpour.

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The degree of the slope supports and catalyses the water flow leading to the flash floods.

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As the water flows, it takes away the unconsolidated material from the higher altitudes and gets accumulated in the foothills, agricultural lands causing much harm to life and property.

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While in the Eastern Himalayas, the valleys are narrow due to intensive anticlines and synclines. Also the Middle Himalayas are missing from the Eastern Himalayas. As a result, the entire moisture laden winds derived from the Bay of Bengal Monsoon Branch cannot climb or ascend through the Greater Himalayas and such downpour at the Shiwaliks starts after condensation.

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This continuous heavy long spanned rainfall cannot be termed as the cloud bursting as it is not accompanied by flash floods or landslides or avalanches etc.

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It is interesting to note that the Kullu Valley, in Himachal Pradesh is the world’s worst affected monsoon regime as it is a transition between the Arabian Sea Monsoon Branch and the Bay of Bengal Monsoon Branch.

5.0 SOCIO-ECONOMIC IMPACT OF CLOUDBURST Cloudburst is a precipitation of heavy rain takes place at a small area .cloudburst cause flash floods results in loss of life, of not only humans but animals also in Uttarakhand in 2013 more than 5500 people were killed which include local people as well as tourists. Heavy rain causes landslides and tree fall which results in the blockage of roads and this blockage create many problems to the people. Damage to roads, destruction of bridges left people and tourists trapped in the valleys which leads to problem in evacuation of those trapped people and destruction of houses and water channels, electricity supply also disrupted as many poles due to poles damage and heavy loss of public property .

Due to Cloudburst and heavy rain there are destructions of vehicles. Vehicles flow away with the floods. Not only this man- made structures such as earthen check dams and bunds also washed away. Cloudburst in plains leads to water logging and inundation. Agriculture is the most sensitive sectors to impact climate change and weather. Due to cloudburst there are floods which damage the agriculture and horticulture. And if agriculture affected whole Indian economy is affected. It is the major demand generating sector. So, Low production will lead to shortage of food, inflation in food, and change in interest rates. Most of the farmers are depend on irrigation by snow and glacial water but heavy rain leads to wear out of fertile top soil in agricultural land and damages the crops which adversely affect

the livelihood of people. Due to crop damage there is loss of livelihoods which leads to debt of farmers and result in poverty. The heavy rain and floods leads to extensive damage and it adversely effect on tourism sector also like Kedarnath - The sought after pilgrim centre in India, is today into ruins after 2013 tragedy. One could only see mud, flash floods and slush in the region that entered the regions through the Kedar Dome (mountain peak) and breaking the Charbari lake reservoir.

Report on the unfortunate news of no religious, adventure and eco-tourism in Uttrakhand, for at least 3 years. During the past decade, the state had contributed to the striking growth in the GDP of 9%. According to the recent study, this about 2.78% is contributed by this sector and about 4.59% employment is generated from the same. Along with tourism, sectors like agriculture, fishery, mining and forestry have also been highly affected.

6.0 PHYSICAL IMPACTS A cloudburst is an extreme amount of precipitation, sometimes with hail and thunder, which normally lasts no longer than a few minutes but is capable of creating flood conditions. Any sudden heavy, brief, and usually unforecastable rainfall. Rainfall rate equal to or greater than 100 mm (3.97 inches) per hour is a cloudburst. If rainfall of about 10 cm or above per hour is recorded over a place that is roughly 10 km x 10 km in area, it is classified as a cloudburst event. It is a phenomenon occurring in hilly and terrain areas but the impacts are visible and can be estimated to the low lying areas. 6.1 Effect of Cloudbursts 1. Flash floods: Cloudbursts are also responsible for flash floods creation. 2. Accompanying effect of Cloudbursts on terrain o Sheet floods o Landslides o Mudflows o Land caving o Flash floods, houses and establishments getting swept away and cave-ins lead to the deaths. o Lose of agricultural fields and the crops growing over there.

o Blocking path of rivers that may lead to temporary damming and creation of a reservoir and its consequent collapse. o The rainfall itself does not result in the death of people, though sometimes, the raindrops are big enough to hurt people in a sustained downpour. It is the consequences of such heavy rain, especially in the hilly terrain, that causes death and destruction. The cloudbursts takes place at the hilly areas and it results in sudden downpour of heavy rainfall in a short span of time. It doesn’t allows the local peoples to immediately ran away from the affected area. Heavy rainfall over the hilly areas erodes the mountainous rocks and debris and then enables them to travel with the flow of water to low lying areas. This leads to sheet floods in the foot hills of the hilly areas. The mud, debris, cobblers starts to accumulate over the agricultural lands. This results in reduction of nutrition efficiency of the soil and makes it barren.

7.0 CASE STUDY 1: UTTARAKHAND DISATER, 2013 Uttarakhand is state in north India popularly known as “Devbhhomi” because of the spiritual and religious tourism it provides. It sits on the extremely fragile Himalayan ecosystem which is a cause for the occurrence of natural disasters like earthquakes, landslides, avalanches, cloudbursts, hailstorms, forest fires etc. In addition to natural phenomenon, various human activities like- unscientific development and land use pattern, deforestation, increasing pressure of tourism and waste disposal have contributed to the vulnerability of the region to hazards. But in June, 2013 during the peak season of tourism and pilgrimage, the region suffered its worst disaster of cloudburst accompanied by landslides and flashfloods which created havoc and caused a huge loss of life and property. 7.1 Background Uttarakhand is located between 28°43’-31°27’ N latitude and 77°34’-81°02’ E longitude and has two divisions- Garhwal and Kumaon and 13 districts. River Kali makes the international boundary between Uttarakhand and Nepal in the east whereas Tons-Bhabhar forms the eastern border of Himachal Pradesh in the west.

Source: National Institute of Disaster Management Several rivers originate from the Uttarakhand Himalays including river Ganga and Yamuna which are lifelines for the most densely-populated Hindi speaking belt of India.

Sour ce: National Institute of Disaster Management 7.2 The Himalayan Tsunami A major disaster struck on 16/17 June 2013 after Cloudbursting led to very heavy rains in the upper parts of the State. According to IMD sources, the state received more than 400% rainfall than the usual due to the fusion of westerlies with the Indian monsoonal cloud system. This heavy precipitation alongwith ablation due to high temperatures led to the swelling of rivers.

Source: National Institute of Disaster Management

The districts of Bageshwar, Chamoli, Pithoragarh, Rudraprayag and Uttarkashi were the most

affected.

Source: Researchgate.net 7.3 Impact of Cloudburst Pilgrimage centres in thess affected places include chota chardham constituting of Yamunotri, and Gangotri in Uttarkashi, Badrinath in Chamoli and Kedarnath in Rudraprayag districts and Gurudwara Sri Hemkund Sahib ji in Chamoli. The worst impact on human settlements was seen in Kedarnath shrine area. Due to cloudburst and subsequent overflow, the moraine dammed Chorabari Lake collapsed which

released large volume of water and sediments leading to devastation in Kedarnath town downstream. The main cause of this collapse was the torrential rains which led to huge accumulation of water. This lake had no outlets and usually water was released through narrow outlets at the bottom of the lake. But due to cloudburst, the potential energy of the water increased and reduced the sheer strength of the dam. Other pilgrimage centres were also affected where people were stranded from days to weeks at isolated locations. The hazard turned into a major disaster when people along with their property and infrastructure occupied such areas without adequate knowledge, information, awareness and preparedness against the potential disaster.

Source: National Institute of Disaster Management

7.4 Casualties and Damages As per the report made available by the State government on 9 May’14 a total of 169 people died and 4,021 people were reported m...