1. Why cloudburst forecast in India still remains elusive
Monitoring stations on the ground can hardly capture cloudburst characteristics due to their highly localised and short occurrence
Cloudbursts — violent and voluminous amounts of rain pouring down in a short duration over a small area — have been reported since the mid-19th century. Yet, the characteristics of these events remain elusive, and our efforts in monitoring and forecasting them is at an embryonic stage. However, their disastrous impact that cause loss of lives and property are seemingly increasing in a changing climate and have led to close observations in the recent decade, advancing our understanding of these events.
Clouds blanket 70% of the Earth’s surface at any given time. They are like a thin layer of the floating ocean, with enough water to cover the entire surface of Earth with about one inch of rain. A modest-sized cloud (1 cubic km) may contain more than 5,00,000 litres of water — equivalent to the mass of hundred elephants.
Cloudburst events are often associated with cumulonimbus clouds that cause thunderstorms and occasionally due to monsoon wind surges and other weather phenomena. Cumulonimbus clouds can grow up to 12-15 km in height through the entire troposphere (occasionally up to 21 km) and can hold huge amounts of water.
However, cloudbursts are not defined based on cloud characteristics and do not indicate clouds exploding. Cloudbursts are defined by the amount of rainfall. According to the India Meteorological Department (IMD), 100 mm of rain in an hour is called a cloudburst. Usually, cloudbursts occur over a small geographical region of 20 to 30 sq. km.
In India, cloudbursts often occur during the monsoon season, when the southwesterly monsoon winds bring in copious amounts of moisture inland. The moist air that converges over land gets lifted as they encounter the hills. The moist air reaches an altitude and gets saturated, and the water starts condensing out of the air forming clouds. This is how clouds usually form, but such an orographic lifting together with a strong moisture convergence can lead to intense cumulonimbus clouds taking in huge volumes of moisture that is dumped during cloudbursts.
Tall cumulonimbus clouds can develop in about half an hour as the moisture updraft happens rapidly, at a pace of 60 to 120 km/hr. A single-cell cloud may last for an hour and dump all the rain in the last 20 to 30 minutes, while some of these clouds merge to form multi-cell storms and last for several hours.
More prone areas
Cloudbursts, hence, occur mostly over the rugged terrains over the Himalayas, the Western Ghats, and northeastern hill States of India. The heavy spells of rain on the fragile steep slopes trigger landslides, debris flows, and flash floods, causing large-scale destruction and loss of people and property.
Recent cloudbursts that caused significant devastation occurred over the Himalayan foothills in Himachal Pradesh (in the year 2003), Ladakh (2010), and Uttarakhand (2013). Cloudbursts were reported from the northeastern States and Western Ghats States during the current monsoon season (2022).
On July 8 2022, flash floods occurred in the Lidder Valley en route to Amarnath Temple in Jammu and Kashmir, taking the lives of several pilgrims. While the media linked this event to cloudbursts that occurred upstream of the temple, there is no meteorological record in the surrounding regions to validate this. Weather forecasts indicated scattered light rains for the region, and the IMD recorded moderate rainfall at the temple station.
Monitoring stations on the ground can hardly capture the cloudburst characteristics due to their highly localised and short occurrence. Hence, most of these events go unreported due to the lack of monitoring mechanisms in the region, weakening our ability to understand these events in complete perspective.
Heavy rains and waterlogging brought Bengaluru to a standstill during the first week of September 2022. Social media was abuzz, passing off a two-year-old video of cloudbursts in Perth, Australia, as Bangalore cloudbursts. None of the city’s weather stations recorded a cloudburst but indicated heavy rains during the week as the monsoon winds gained strength due to a low-pressure area developing in the Arabian Sea.
Strong monsoon wind surges along the coast can also result in cloudbursts, as in the case of Mumbai (2005) and Chennai (2015). Coastal cities are particularly vulnerable to cloudbursts since the flash floods make the conventional stormwater and flood management policies in these cities dysfunctional.
While satellites are extensively useful in detecting large-scale monsoon weather systems, the resolution of the precipitation radars of these satellites can be much smaller than the area of individual cloudburst events, and hence they go undetected. Weather forecast models also face a similar challenge in simulating the clouds at a high resolution.
The skillful forecasting of rainfall in hilly regions remains challenging due to the uncertainties in the interaction between the moisture convergence and the hilly terrain, the cloud microphysics, and the heating-cooling mechanisms at different atmospheric levels. The IMD’s forecasts, and in general, the weather prediction scenario, have advanced such that widespread extreme rains can be predicted two-three days in advance. Cyclones can be predicted about one week in advance. However, cloudburst forecasts still remain elusive.
Multiple doppler weather radars can be used to monitor moving cloud droplets and help to provide nowcasts (forecasts for the next three hours). This can be a quick measure for providing warnings, but radars are an expensive affair, and installing them across the country may not be practically feasible.
A long-term measure would be mapping the cloudburst-prone regions using automatic rain gauges. If cloudburst-prone regions are co-located with landslide-prone regions, these locations can be designated as hazardous. The risk at these locations would be huge, and people should be moved, and construction and mining in nearby regions should be restricted as that can aggravate the landslides and flash flood impacts.
Climate change is projected to increase the frequency and intensity of cloudbursts worldwide. As the air gets warmer, it can hold more moisture and for a longer time. We call this the Clausius Clapeyron relationship. A 1-degree Celsius rise in temperature may correspond to a 7-10% increase in moisture and rainfall. This increase in rainfall amount does not get spread moderately throughout the season. As the moisture holding capacity of air increases, it results in prolonged dry periods intermittent with short spells of extreme rains. More deeper cumulonimbus clouds form and the chances of cloudbursts also increase.
Cloudbursts are reported frequently from across the country. The climate change signal is conspicuous, but we do not have long-term (20 years or more) hourly data to attest it. With IMD enhancing its automatic weather stations, we may have hourly data that can help map cloudburst-prone regions.
The change in monsoon extremes and cloudbursts we see now are in response to the 1-degree Celsius rise in global surface temperature. As emissions continue to increase and global commitment to reduce emissions proves insufficient, these temperatures are set to hit 1.5°C during 2020-2040 and 2°C during 2040-2060. We will need urgent action and policies to protect lives and property from extreme events that will amplify as the global temperature change doubles.
2. What is the G7 planning on Russian oil?
How will imposing a price cap on oil purchases from Russia help? How is India responding to the West’s call?
The story so far: On September 2, Finance Ministers of all G7 countries, the U.S., Canada, the U.K., France, Germany, Italy, Japan, as well as the European Union announced their plan to “finalise and implement a comprehensive prohibition of services which enable maritime transportation of Russian-origin crude oil and petroleum products globally”, unless they are purchased at or below a “price cap” they will fix. The plan, however, doesn’t include Russian gas, which Europe is still quite dependent on.
What is the price cap plan?
The price cap plan is the latest of the sanctions proposed by Western countries against Russia for its invasion of Ukraine, as well as Belarus for its support to Russia. For the past few weeks, U.S. and EU officials have been trying to convince countries including India, China and Turkey to join the coalition or to at least support the price cap, which they say is in the interests of all oil buyers from Russia as it will give them leverage to lower purchase prices.
How will it be enforced?
For countries that join the coalition, it would mean simply not buying Russian oil unless the price is reduced to where the cap is determined. For countries that don’t join the coalition, or buy oil higher than the cap price, they would lose access to all services provided by the coalition countries including for example, insurance, currency payment, facilitation and vessel clearances for their shipments. G7 countries say they are aiming to reduce the price of oil, but not the quantity of oil that Russia sells, so as to control inflation globally while hurting the Russian economy and its ability to fund the war in Ukraine. This could only work, of course, if all countries joined the coalition.
How has Russia reacted to the plan?
Russian President Vladimir Putin has lashed out at the plan, warning that Russia would not supply “anything at all” if it contradicts Russian interests. Speaking at the Eastern Economic Forum (EEF) in Vladivostok this week, that Prime Minister Narendra Modi joined virtually, he threatened that Russia could stop supplies of gas, oil, coal, heating oil… leaving European countries to “freeze”. On September 5, Russia also announced a halt on all supplies via the Nord Stream 1 pipeline to Europe due to “maintenance issues” arising from the EU sanctions already in place, raising fears of a very difficult winter for European countries.
Will the Modi government comply with the price cap?
The price cap is only the latest in a number of sanctions to hurt the Russian economy that the U.S. and EU have tried to bring India on board with: from asking India to change its uncritical stance on Russia at the United Nations, to cutting down oil imports, to stopping defence and other purchases from Russia, and to avoid the rupee-rouble payment mechanism that circumvent their sanctions. Thus far, India has not obliged, and there is little indication that New Delhi is likely to, just yet. India’s oil intake from Russia, which was minuscule prior to the war has soared 50 times over. When asked, Petroleum Minister Hardeep Puri rejected any “moral” duty to join the price cap coalition, and said his only duty was to providing affordable oil to Indian consumers. At the EEF, Mr. Modi said he wanted to “strengthen” ties with Russia in the energy field and boost India’s $16 billion investment in Russian oilfields. This week, Mr. Modi will also join President Putin, Chinese President Xi Jinping, Turkish President Recep Tayyip Erdogan and other leaders at the Shanghai Cooperation Organisation summit in Uzbekistan, where the price cap issue will no doubt be discussed from the opposite viewpoint to the G7’s. It also remains to be seen whether India will bargain with the U.S. to set aside sanctions against Iran and Venezuela, from which it cancelled oil imports under pressure from the U.S. in 2017-18, in exchange for joining the price cap coalition.
3. Why is the Kushiyara river treaty important?
What is the status of the Teesta River water sharing proposal between India and Bangladesh?
The story so far: During Bangladesh Prime Minister Sheikh Hasina’s visit to India from September 5 to 8, the two sides signed a slew of agreements, including the first water sharing agreement since the landmark Ganga Waters Treaty, 1996. A memorandum of understanding (MoU) was signed on sharing of the waters of the Kushiyara river, a distributary of the Barak river which flows through Assam, and then on to Bangladesh. The agreement comes in a year when both lower Assam in India and Sylhet in Bangladesh have witnessed deadly floods highlighting the requirement for greater cooperation on flood control and irrigation-related issues between the two countries.
What is the Kushiyara agreement?
Over the last century, the flow of the Barak river has changed in such a way that the bulk of the river’s water flows into Kushiyara while the rest goes into Surma. According to water expert, Dr. Ainun Nishat, the agreement is aimed at addressing part of the problem that the changing nature of the river has posed before Bangladesh as it unleashes floods during the monsoon and goes dry during the winter when demand of water goes up because of a crop cycle in Sylhet. Though the details of the agreement are not yet known, Dr. Nishat says that under this MoU, Bangladesh will be able to withdraw 153 cusecs (cubic feet per second) of water from the Kushiyara out of the approximately 2,500 cusecs of water that is there in the river during the winter season. There are various estimates about the area that will benefit from this supply but it is generally understood that approximately 10,000 hectares of land and millions of people will benefit from the water that will flow through a network of canals in Sylhet benefiting the farmers involved in Boro rice, which is basically the rice cultivated during the dry season of December to February and harvested in early summer. Bangladesh has been complaining that the Boro rice cultivation in the region had been suffering as India did not allow it to withdraw the required water from the Kushiyara. The agreement addresses Bangladesh’s concern over water supply along the river, during the winter months but flood control in the basin of Kushiyara is expected to require much more work.
How will Bangladesh use the water?
The water of Kushiyara will be channelled through the Rahimpur Canal project in Sylhet. The Rahimpur Canal project in Zakiganj upazila or subdivision of Sylhet was built to help the farmers access Kushiyara’s water but the facility used to remain dry during the lean season without serving the purpose for which it was built. The eight km long canal is the only supplier of water from the Kushiyara to the region and Bangladesh has built a pump house and other facilities for withdrawal of water that can now be utilised.
Why is the water from the Kushiyara so important for Rahimpur Canal?
The water of the Kushiyara has been used for centuries in Sylhet’s subdivisions like the Zakiganj, Kanaighat and Beanibazar areas. But Bangladesh has witnessed that the flow and volume of water in the canal has reduced during the lean season. The utility of the river and the canal during the lean/winter season had gone down, affecting cultivation of rice as well as a wide variety of vegetables for which Sylhet is famous. The additional water of Kushiyara through the Rahimpur Canal therefore is the only way to ensure steady supply of water for irrigation of agriculture fields and orchards of the subdivisions of Sylhet.
What was India’s objection to the Rahimpur Canal?
The Kushiyara water sharing agreement finalised during the August 25 Joint River Commission and signed during Prime Minister Hasina’s visit was made possible as India withdrew its objection to withdrawal of Kushiyara’s waters by Bangladesh through the Rahimpur Canal. Withdrawal of India’s objection is likely the main part of the agreement, said Dr. Nishat. Before this, Bangladesh had carried out the Upper Surma Kushiyara Project which included clearing and dredging of the canal and other connected channels of water; but the channels could not be of much use to Bangladesh because India objected to the move and claimed that the dyke and other infrastructure interfered in border security as Kushiyara itself forms part of the border between the two sides. However, the agreement indicates that the economic benefits possible from the river outweighed the security concerns.
What are the hurdles to the Teesta agreement?
The Kushiyara agreement is relatively smaller in scale in comparison to Teesta that involves West Bengal, which has problems with the proposal. The Kushiyara agreement did not require a nod from any of the States like Assam from which the Barak emerges and branches into Kushiyara and Surma.The reduced water flow of the Kushiyara during winter and Teesta too, however, raise important questions about the impact of climate change on South Asian rivers that can affect communities and trigger migration. Bangladesh has cited low water flow in its rivers during the winter months as a matter of concern as it affects its agriculture sector. Dr. Nishat contends that the coming decades will throw up similar challenging issues involving river water sharing as the impact of the climate crisis becomes more visible with water levels going down in several cross-border rivers.
4. Risk from rabies
Which virus causes the disease? What is the treatment protocol? Are vaccines effective?
The story so far: The death of a 12-year-old girl in Kerala from rabies, despite having multiple inoculations of the vaccine, has raised questions on the efficacy of rabies vaccines in India and their availability.
How does a rabies vaccine work?
Rabies is a disease that is caused by a family of viruses called the lyssaviruses and found in a range of mammals. The virus targets the central nervous system and is nearly 100% fatal to the host animal if it succeeds in infecting it. Though many animals from cats to crocodiles can be transmitters of the virus, it is most likely to spread to people from the bite of an infected dog or a cat as they are the most common pets. Despite being potentially lethal, the virus is slow-moving and it can be several weeks before the disease manifests into a fatal encephalitis which is why administering a vaccine, even after being bitten by a rabid animal, is effective. A shot of rabies immunoglobulin (rabies-antibodies against the virus derived either from people or horses) followed by a four-week course of anti-rabies vaccine, is nearly guaranteed to prevent rabies. This translates to the first dose being given on the same day as the immunoglobulin followed by vaccinations on the 3rd, 7th and 14th day. There are other regimens, such as five shots which include one on the 28th day approved by the World Health Organization (WHO) which clinics may consider, depending on the availability of the vaccine.
How is the vaccine made?
The vaccine is made up of an inactivated virus that is expected to induce the body into producing antibodies that can neutralise the live virus in case of infection. There are also test vaccines that involve genetically modified viruses. There is no single-shot rabies vaccine or one that offers permanent immunity. There are mainly two ways of administering the rabies vaccine. One, called post-exposure prophylaxis (PEP), is given to persons who have been exposed via a bite to an animal suspected to be infected. The vaccines are administered either into the muscles, or into the skin. It can also be given ahead of time to persons who have a high risk of being infected, such as veterinarians, animal handlers, areas with a high number of rabies infection, by what is called Pre Exposure Prophylaxis (PrEP). The advantage of a PrEP is that if bitten, one doesn’t need a immunoglobulin injection, and two subsequent shots of the vaccine will suffice for full protection, unlike the four-course prescription in the case of PEP. However, the WHO doesn’t recommend PrEP as a general preventive.
Are rabies vaccines easily available in India?
According to the Health Ministry, there are at least six rabies vaccines approved for India. They all contain inactivated virus made of duck, chicken or human cell cultures and are marked as safe, efficacious and with long immunity. Rabies vaccines are available for free in government dispensaries though vaccines administered in a private clinic can cost up to ₹500 per dose. However, reports of hospitals running out of vaccines continue to surface and knowledge about vaccines and treatment is still inadequate in India. The Health Ministry has said that no centralised database of vaccine availability is maintained, being a State-procured product, but that shortage had been reported in Punjab, Haryana, West Bengal and Karnataka. The Centre says that from 2016-18, around 300 laboratory-confirmed rabies deaths were reported in India. The WHO says India is endemic for rabies and accounts for 36% of the world’s deaths. The true burden of rabies in India is not fully known; although as per available information, it causes 18,000-20,000 deaths every year. About 30-60% of reported rabies cases and deaths in India occur in children under the age of 15 years, as bites that occur in children often go unrecognised and unreported, it notes.
What about vaccines for animals?
Given that rabies treatment requires multiple shots of vaccine as well as immunoglobin, sticking to the schedule is challenging. Governments of countries where rabies is endemic have frequently set targets to eliminate the disease — India has committed to do so by 2030. Yet it is widely acknowledged that this elimination requires vaccination of dogs. Like in people, vaccinating animals too doesn’t guarantee lifelong immunity from the disease. Because dogs are deemed responsible for 99% of all rabies infections in people, the government in its 2021 plan, called the ‘National Action for Plan — Rabies Elimination’, aims to vaccinate at least 70% of all dogs in a defined geographical area annually for three consecutive years. With this, a degree of herd immunity is expected leading to eventual elimination within eight years. Rather than inoculate all dogs, the plan is to identify ‘rabies hotspots’ in the country and target them.