Monsoon floods in Bangladesh: To be or not to be

While writing this article sitting at my desk, the calendar besides the laptop is set on the Ashara (June-July), the first Bengali month of the monsoon season. The outer nature across the window is embracing the downpour. As perfect as Rabindranath Tagore has said- ‘the darkly veiled Ashara has come once again’.

Not only in Bangladesh, heavy rains have been going on for a week in West Bengal and the northeastern states of India as well. There are reports of flooding of crop fields and houses upstream of Teesta, Brahmaputra, and Barak basins.

Almost every year, floods come in Bangladesh exactly at this situation. It is an inevitable natural process in the Bengal Delta built and nourished by hundreds of meandering rivers at the foothills of the Himalayas.

Rainfall in northeast India, one of the rainiest regions in the world, sends seasonal flooding here in Bangladesh. If it occurs simultaneously in two or three of the Ganga, Brahmaputra, and Barak basins, it becomes catastrophic. In the near past, Bangladesh had seen such catastrophic floods in the years of 1988, 1994, 1998, 2004, 2007, 2014 and 2017.

This situation is totally different so far this year. Generally, the northeastern districts of Bangladesh experience early floods from the middle of Baisakh month, that is April-May. So people and peasants of the ‘Haor’ or vast wetland region of these districts rush to harvest the Boro Paddy, the only rice variety cultivated there, from the farmland.

This early flood has not come this year. Rather people have been waiting for the flood to celebrate the culture and cuisine linked to the flood season.

Monsoon floods in Bangladesh usually occur during heavy rains; in the month of Ashar to Shravan (June to August). But even till the half of the month of Ashar, flood is yet to show up. Though some of the national news outlets have already been hearing the 'footsteps' of the flood, it is probably not the seasonal monsoon flood.

Though the Surma-Kushiara or Barak basin is inundated due to local and regional rainfall, it is temporarily stagnant water. Though the water is rising in the Teesta River basin, only the chars or the landmass along the riverbed may be inundated. Inevitably, there will be erosion along the river banks.

There are reports of flooding in 12 districts of the Brahmaputra basin in upstream Assam state of India caused by excessive rainfall. But when that water comes down to Bangladesh, it will lose its speed and extent to a large extent while filling the wetlands on both sides of the river. So only the river bed of Brahmaputra may be flooded in Bangladesh. Even in the Ganges basin in Bangladesh, the flood still is a distant sound.

In fact, while writing this article at noon, only three river stations on the website of the Water Development Board's Flood Forecasting and Warning Center showed yellow signs. The river water measuring stations are situated on the Teesta, Khoai and Surma Rivers.

There are 112 water level measuring stations in different river basins across the country.

Flood Forecasting and Warning Center's dynamic website provides an overview of the country's flood situation by getting data from these stations.

The forecast map has four colour signs to indicate the situation. Green means river flow is normal; no risk of flooding. If the river flow begins to rise and remains below the flood line, the indicator will be yellow. The indicators will turn orange when the danger limit is reached or flooding occurs. It will turn red in case of a heavy flood.

Why is the seasonal flood so late for Bangladesh this year? Apparently due to the late monsoon. One of two branches of monsoon wind, originating from the Indian Ocean, enters Bangladesh, West Bengal and Assam through the Bay of Bengal.

It is usually on the 1st day of the month of Ashara and spreads over the country by the next two weeks. Again, Tagore, who termed the day as 'Asharashya Pratham Dibas' usually comes with rainfall. The Kadam or burflower blooms with the touch of the first drop of rain.

This year the monsoon wind has been stuck in the bay for a week. As a result, Bangladesh has seen the first drop of rain after almost two weeks of the month of Asara.

This year, the monsoon rainfall across the subcontinent is a bit erratic from a meteorological point of view, in fact. Not only the Bay of Bengal branch, but also the Arabian Sea branch has also been delayed. As a result, the monsoon flood is yet to come.

The delayed or even absence of monsoon floods has serious consequences for a country like Bangladesh. First, the ecological importance of seasonal floods in the Bengal Delta is immense. Just as flooding preserves the fertility of cropland, it also raises inlands and expands the coastline.

It keeps the link between rivers and wetlands alive; conserves the aquatic habitat and breeding processes. Apart from these long-term issues, the immediate blessing of the flood in Bangladesh is the Aman crop.

Although boro rice has become the staple crop of farmers in the last few decades after the so-called green revolution; the importance of Aman rice lies elsewhere.

Boro rice cultivation area and yield is more than Aman, no doubt. But the cost of cultivation, irrigation, fertilizers, pesticides, labour required for Boro production is also very high. Sometimes the production cost exceeds the market price of the harvested crop.

On the other hand, there is far less production cost needed for Aman rice. As no additional tillage is necessary when planting Aman seedlings in soft soil during the Shraban-Bhadra months after the flood recedes; irrigation too is not required due to the blessing of rainfall. That's why the farmer's rituals, kinship, hobbies, and formal cuisine; all depend on the production of Aman rice.

If the monsoon floods are delayed or not this time, if the last days of Shravan suffer from a lack of rain like the first days of Ashara, then the Aman season will be delayed or, in the worst case, can be less yielding.

What to prepare for a flood, how to conduct rescue operations, what to do with relief and rehabilitation – these are easy to determine. But what if the flood is delayed or not at all? We may urge to subsidise or provide incentives to the farmers to keep the Aman season on.

More worryingly, how will we protect the ecological damage caused by the absence of seasonal flood? It is clear that such a situation may become more frequent in the coming years due to climate change. Are we prepared for that? Let’s think of it.

Sheikh Rokon: River Activist and Researcher