India is battling deadly rain storms caused by climate change
A Myanmar Flood-Flood Disaster Watcher: Emmanuel and his Volunteers in the Dryland (Kangoor) Primary School
Last year, around two-thirds of Pakistan was affected by widespread flash flooding, with more than 1,500 people killed and around 33 million made homeless. More than 2000 people died in flash floods across Africa, and many parts of the Arabian peninsula were submerged with water.
Dryland residents are paying a high price. Our analysis using the Emergency Events Database (EM-DAT; www.emdat.be) shows that, since 2000, such regions experienced less than half (47%) of deadly flash floods globally, yet saw almost three-quarters (74%) of related deaths (see ‘Global flash-flood disasters’). The majority of these floods (87%) and associated deaths (97%) occurred in low- and middle-income countries.
Every year, neighboring Cameroon — which runs along the length of Nigeria’s eastern border — releases water from a dam in northern Cameroon, causing flooding downstream in Nigeria. In the 1980s, the two countries agreed that a twin dam on the Nigerian side would be built to stop the overflow. But the second one was never realized.
On a beautiful day a week after last summer’s monsoon ended, Emmanuel walked into the courtyard at St Joseph’s Upper Primary School in Malayinchippara, where he was greeted by the deafening sound of a marching band. This is one of 220 outposts where Emmanuel has set up rain- and river-monitoring gauges. He says the visit is meant to motivate his volunteers, but the students already take this effort seriously. Job Jose says that a landslide destroyed his neighbour’s house, and he and his family lost their well. Meera Binoy saw flood waters enter her house and damage some timber. Speaking in Malayalam, “A cloud burst open,” she says, alluding to a convective storm.
Emmanuel, the secretary of the Meenachil River Protection Council in Kidangoor, a collective of local river conservationists, quickly organized with other community workers and the Kottayam fire department to evacuate the people. But one resident, T. Raju, refused to abandon his belongings. He lay down on his stringed bed frame, figuring he had seen plenty of bad rains. His television floated by as his bed moved. This was not normal.
In an interview with Nature in October, he said that he jumped up, grabbed clothes and went to the evacuate site. He pointed to a 1.5 metres up wall of water that poured into his home during the flood.
The monsoon that hit the state ofKerala in August caused what people call the Pralayam, a flood to end the Universe in the Hindu religion. It was the biggest in the state since 1924. More than 400 people died, more than one million were displaced and damages amounted to US$4.25 billion, according to an Indian government report2.
Emmanuel’s problem with tropical rains and thunderstorms “remains a mystery for millions of people in South Asia,” he told AFP
The sound of the rain starts to make me sad. It is not like before, where we were sleeping peacefully even when it was raining. But not any more.”
The human element in extreme weather risk makes it challenging for meteorologists to issue granular ‘impact-based forecasts’ that warn people about events such as flooding, lightning strikes and landslides in their immediate vicinity. The community on the river decided to take care of themselves. “We are not following the IMD,” Emmanuel says, referring to government forecasts. “We are depending on our trusted volunteers’ reporting.”
It is difficult to forecast Tropical rain and thunderstorms in advance at the scale of neighbourhoods or towns. Many of the two billion people in South Asia don’t receive news alert and therefore have difficulty communicating forecasts.
There has been a surge of bad news in the region over the past year. During March and April, a heatwave gripped India and Pakistan, killing at least 90 people and destroying wheat crops, which exacerbated a worldwide shortage of grain caused by the war in Ukraine. May saw landslides, floods and heavy downpours in northeast India. The monsoon arrived in June with a lot of flooding. Pakistan was flooded after weeks of intense rain in August. More than 1,500 people died and more than $30 billion was spent.
Within days, the winds can find gaps in the Western Ghats and deliver rain across the subcontinent. By the time the monsoon ends in India, usually in September, it will have dumped an average of 850 millimetres of rain — more than three-quarters of the country’s annual total.
Over the past seven decades the monsoon has become erratic due to a tendency towards extreme precipitation and sudden droughts. Since 1870 the Indian Ocean has warmed by more than other oceans, and this is part of the reason. He says that marine heatwaves cause extreme rises in ocean temperatures. The trade winds appeared to have weakened.
According to government data, about 95% of India’s extreme weather deaths last year were caused by storms, lightning and heavy rains. The rain is no longer predictable. In the worst cases, clouds can grow rapidly and deposit more than 100 millimetres of rainfall in an hour over a single neighbourhood.
“We have a wide spectrum of users,” says Soma Sen Roy, an atmospheric scientist at the IMD in New Delhi. “We have people who are advanced at handling mobiles or computers. And there are people who have never seen a computer or mobile in their life.”
The Kerala River Protection Council (Meenachil): The need for data sharing in the open domain for forecasting monsoon events
“If rain is there for one day all over Kerala, the entire Kerala is flooded. Not because there is more water, but because the water has no way to flow easily,” says S. Ramachandran, president of the Meenachil River Protection Council.
The IMD can forecast some of these events two days in advance. It says the 10-day forecasts are even less accurate than the 5 day forecasts.
Forecasting storms before they develop requires a dense array of observation stations, which does not exist in the region. The IMD has the best set-up in South Asia, and it gets data from 33 doppler weather radars, 56 balloon-launching sites, 25 lightning-detection sensors and 725 automatic weather stations, as well as meteorological satellites, ships and other sources. The Indian government, along with the US National Oceanic and Atmospheric Administration operate observation pieces on the Indian Ocean.
Only a small amount of these data are shared or used in monsoon forecasts. We need data in the open domain to be able to use it for cutting-edge research. He adds that the IMD sometimes releases data when requested, but the process is slow and it doesn’t provide all data. The IMD’s Hosalikar states that data is freely available for researchers except for commercial purposes.
Millions of small growers on the India’sGangetic Plain flood their fields with water during the dry season. The weather forecasting models predict that evaporation of this irrigation water should cool the land surface and ease heatwaves. Mondal found that existing models underestimate the cooling by more than five times. “There’s so much happening at the local scale, which is also hard to measure and predict,” she says. This gap is created when what is predicted is actually happening on the ground.
Source: https://www.nature.com/articles/d41586-023-00341-5
Adaptation to climate change in the Meenachil River: a case study of a village-based early-warning system
Koshy had a top floor built in her house along with a ramp to fit her wheelchair, a few months after the floods. She says that people in her village built upwards in response to the flooding.
The local water cycle can become overwhelmed as a result of changes in land use, and sometimes because managers make the wrong decisions as a result.
The children send their daily precipitation and river-flow measurement to a group that oversees the operation in a rain book. P C. Jose is a retired bank manager in a nearby village. He is part of a team that analyses readings from 220 river gauge and 13 rain gauge spread across the 1,272-square-kilometre Watershed. There is a measurement done once a day when there is no rain. During the rains, the team increases the frequency to once an hour or more.
As a result of their data and deep knowledge of the surrounding terrain, Emmanuel and his team can predict when areas downhill will flood. It is not completely scientific but it works. The group is collaborating with Koll, whose family hails from this area, to ensure scientifically rigorous data collection through an online portal so they can automate forecasts in the future.
This effort is the best working example of grassroots actions that can be made to adapt to climate change according to the Intergovernmental Panel on Climate Change. The early-warning system along the Meenachil River “can be tailored for climate action across similar environments across South Asia that face similar climate challenges and land–river use changes”, adds Koll.
After visiting his volunteers all day, Emmanuel took a break in an office he shares with another community group. He pointed at a traditional lunar calendar hanging on a wall. Farmers use it to plan their planting and harvesting schedule, but these days, nature’s rhythm is wonky: there is less constant rainfall, and more unpredictable fury. The early-warning system is needed greatly, he says. But keeping volunteers on track, recruiting new members, ensuring data collection, getting buy-in from local officials and securing funding for gauges all take up a lot of his time. He is committed to the community because of his family’s legacy of elected leaders and social workers.
Source: https://www.nature.com/articles/d41586-023-00341-5
Building for the future: how the China, India and China will prepare for the next generation of flash floods in the next millennium, a century before the next century
He knows it could not last unless he builds a strong team. When I stand still, something may stop. But I hope that is not going to happen.”
There are less prepared residents of the drylands for flash floods than in the tropics. In dry areas, where drought is a big concern, settlements tend to be near rivers or on floodplains. Dams and levees are low priorities.
More people are living in drylands — from 40% of the global population in 2000 to 44% in 2020, by our calculation. Half of people living in low-income countries will be part of the population boom in these regions, and only 1% of them will be in the developed world. In areas such as the Middle East, India and China, the cities are growing rapidly. As the world warms, the proportion of arid land area is predicted to increase from 41% in 2000 to 48% by 2041.
Governments should plan for temporary and permanent relocation in flood-prone areas. Elevated roads, evacuation routes and emergency shelters must be designed, such as those used in Indonesia for tsunamis and in the United States for hurricanes. In the longer term, as climate-change impacts accelerate, managed retreat might be required8. Over the past 10 years, the Chinese government has relocated more than 600,000 people from flash-flood zones in the southern portion of Shaanxi province.
Dryland will need to be protected with dam, barriers, and dikes. For example, China has been building thousands of kilometres of levees along the main stream and tributaries of the Yellow River. This is expensive, however, involving hundreds of projects with costs ranging from millions to billions of dollars.
Land-use regulations need to be tightened, such as by preventing informal development in floodplains. Flood-protection standards for buildings need to be improved. For example, the International Residential Code, used as the basis of many national and local guidelines, requires the lowest floors of buildings to be 30 centimetres above the average level of a ‘once a century’ flood. Flood risk in a warming world is no longer reflected by such levels.
It’s cheaper to use nature based solutions. For example, in Pakistan, the government of Khyber Pakhtunkhwa province has restored almost 350,000 hectares of forests in its ‘Billion Tree Tsunami’ planting drive. In the Yolo Bypass project in Sacramento, California, levees are being replaced with weirs to divert flood waters away from houses and onto natural floodplains. Large residential areas should adopt ‘sponge city’ techniques that reduce run-off, such as permeable pavements, green roofs, rainwater harvesting and swales (ditches). These are being installed in cities throughout China, including Xining in Qinghai province, the largest city on the Tibetan Plateau.
Natural features are important for storing and conveying water and for being able to handle extreme floods. Local differences in soil and vegetation conditions must be considered. There is more to know about how to maintain the systems. There are several promising projects that include the World Bank’s Global program on nature- based solutions for climate resilience and water and soil preservation initiatives in north-central China.
Source: https://www.nature.com/articles/d41586-023-00626-9
Uncovering the issues of human resilience in dryland flood risk management: a cross-disciplinary research perspective from Beijing, South Korea, and Zaragoza
It is better to leave people to fend for themselves than it is to have a managed resettling. Cross-disciplinary research in social science, geography, engineering and psychology is required to investigate the best way to manage retreat, by providing essential services and assistance while avoiding food insecurity and lost livelihoods.
Drylands should be the location of risk-transfer schemes. There is a national system of flood insurance in China. These have been incorporated into the national emergency-management system and launched in dozens of pilot cities, including Zhengzhou in Henan province. Weather index insurance, which offers compensation for loss of crops and livestock when rainfall exceeds a threshold, is one such product. Super typhoons and floods that occur once in 1000 years are not insured because they are too expensive.
It has been made mandatory in Algeria. Every insurance company must join the Catastrophe Risk Insurance Pool to cover losses in proportion to their market share. The government sets premiums for properties that are insured.
Collective behaviours also need to be understood11. Data mining and artificial intelligence can provide rapid information about locations, impacts and answers to dryland floods through social-media messages. Models can integrate human behavior into risk assessments. As flood risks evolve, it’s important to adjust policies. There will be need for interdisciplinary analysis to evaluate the effectiveness of flood resilience strategies.
