Asian floods overshadowed by Houston flooding

Each year in late May, the summer monsoon starts at the southern tip of India and spreads northwards. Over the course of the following four months, enormous quantities of rain – roughly three quarters of the annual precipitation – fall on the subcontinent. This rain brings flooding and destruction – and not just in areas that experience extreme rainfall. Normal life also grinds to a halt along the Ganges, Brahmaputra and other rivers, along which huge masses of water roll for hundreds of kilometres down towards the Indian Ocean.

The 2017 monsoon was exceptional, both in terms of its duration and impact. In Nepal, the rainy season lasted from 12 June to 16 October, instead of until around 23 September as it normally does. The 127 days made it 20% longer than normal and almost as long as in the record year of 2008 (130 days). On the other hand, the total amount of rain was not exceptional: an average of 1,330 mm of rain fell across all of Nepal, equivalent to 92% of the usual amount. 

However, a local and time-resolved analysis presents a different picture. Due to orographic lift, the largest amount of rain falls in regions close to the Himalayas – with extreme temporal variations in intensity. The areas worst affected in 2017 included the Indian provinces of Assam, Uttar Pradesh – India's most densely populated province and home to 220 million people – and Bihar, as well as the Terai plains in Nepal. 

The latter is a lowland region between 25 and 100 kilometres wide running for some 800 kilometres along the border with India. It makes up 17% of the area of Nepal, is home to half of the country’s population, and includes 53% of the arable land area. In the twelve districts affected, three quarters of the land was under water. According to the United Nations, these were the worst floods for 15 years.
 
There was also flooding in other regions triggered by torrential rain. Twelve years after the 2005 disaster, the west coast megacity of Mumbai was again hit by floods, with 315 mm of rain falling in the space of twelve hours on 29 August. Even though this was only one third of the 24-hour rainfall experienced on 26 July 2005, the city once again found itself submerged in the floodwaters, which this time extended over a much larger area. Mumbai may now be better equipped to deal with flooding than it was in 2005, but flood alerts are still being issued too late. There are no emergency plans in place and, most importantly, unrestricted and uncontrolled development is taking place over natural drainage paths. 

In West Bengal and Bangladesh, the extensive flooding resulted less from local rainfall than from the waters carried down by rivers flowing from the north.

More than 40 million people were affected by the floods in India, Nepal and Bangladesh between the start of June and mid-October. At least 2,670 people died (2,170 in India, 160 in Nepal, 340 in Bangladesh), with dozens of lives being claimed by landslides in the mountains of Nepal.

The bulk of the losses were incurred in the northeastern part of South Asia. Of the overall losses of around US$ 3.5bn, some US$ 2.5bn occurred in India, 600m in Nepal and 350m in Bangladesh. The percentage of insured losses was negligible in all three countries. While these may be small amounts in comparison with the hurricane losses in North America, they affect countries where people's livelihoods are already extremely vulnerable and unstable.

In Nepal, agriculture and livestock farming was badly hit: 40 million hectares of land was flooded and 70,000 domestic and farm animals perished. Virtually nothing was insured. Farmers are generally reluctant to take out insurance, and are also unwilling or unable to make other provisions. A survey carried out by the United Nations in Terai in October 2017 found that only one third of respondents had made any provision against flood losses, even though 56% had suffered losses in previous years.

In addition, electricity generation from hydropower was severely restricted. Enormous quantities of sediment in the rivers blocked hydropower intake structures, posing a risk of damage to the turbines. There were also countless bridges damaged and culverts blocked by debris. In the Sauraha Safari Park in the southwest of Nepal, 110 hotels were forced to close. The majority of the small amount of insured losses were at industrial facilities (warehouses), in the construction and engineering sectors, or affected motor vehicles.

In Bangladesh, numerous rivers burst their banks and vast areas of this extremely flat country were inundated. Roads, bridges, railway lines and over 750,000 houses were damaged, with over 100,000 destroyed.

India, Nepal and Bangladesh are among the countries with the highest flood risk. Some 12% of the territory of India (400,000 km2) is made up of potential flood zones along the banks of rivers, while in Bangladesh three quarters of the country is affected. More than half the population of Nepal lives in the 20% flood zone area.

In addition to the direct risk of drowning, there are frequent fatalities from electric shocks, particularly in cities. Wading through heavily polluted water regularly results in bacterial infections (especially leptospirosis) that can often be fatal. House foundations are undermined or weakened to the point where they collapse.

A lack of available options is often the reason that few preventive measures are taken. People do not have enough financial resources, and there is insufficient help from government agencies to identify and implement appropriate solutions. What is more, direct initiatives on the part of the state are rare. Yet it is an undisputed fact that prevention saves money and alleviates suffering and distress. Governments are under an obligation to create at least rudimentary structures (and thereby assume a role model function), on which the population can then build. Institutions like the All India Disaster Mitigation Institute (AIDMI) have long recognised that insurance against flood risks – whether in its traditional form or as microinsurance – makes an invaluable contribution to disaster management. Even if cultural obstacles still exist, there is enormous potential for change. India, for example, has achieved substantial improvements through the introduction of crop insurance.

South Asia is representative for the many poorer regions of the world that were afflicted with flood disasters over the last year. South Thailand, Peru, Colombia, Sierra Leone and the Congo were also affected. In absolute terms, losses are often one or two orders of magnitude smaller than in Europe or North America. Yet the impact on people's lives and livelihoods in these poorer countries is generally much more dramatic, given the frequent lack of insurance cover that could otherwise cushion the negative consequences. It has been shown time and again that countries with an effective insurance system against natural hazards are able to return to normal conditions after a disaster much faster than countries without any such protection in place.

Whereas the trail of devastation in the flood regions of Asia and Africa could still be seen weeks and even months after the event, life in Houston had returned to almost normal just a few days after the flooding. Apart from one or two tell-tale signs, it was difficult to find any evidence that large parts of the city had been a metre deep in water a short time before. So the primary goal of the countries affected must be to reduce the vulnerability of their citizens and to make existing systems more robust and resilient.