Home ›› 08 Jun 2022 ›› Opinion
As climate change is set to make flooding worse in Bangladesh, researchers are racing to find adaptations that balance their restorative and destructive powers. Being a riverine country, a great portion of Bangladesh is flooded every year. The flood mainly occurs during the monsoon period of early July to late September.
However, this year even in May floods are being experienced in some floodplains of the Teesta and Jamuna rivers, as well as the lower southern portion of the country. Bangladesh is one of the countries most susceptible to floods in South Asia, as well as to the consequences of climate change. It is upsetting to note that overall flood situation of the country is fast deteriorating. New areas of Sylhet City, Sunamganj town, Chhatak and Doarabazar upazila were flooded as three major rivers-the Surma, Kushiyara and Sari-Gowain are flowing over the danger level. At the same time, a number of rivers of the Barishal region have been flowing over the danger level due to upstream water. City dwellers of the said areas have fallen into extreme difficulty following disruption of civic amenities due to flood water. Power supply has been severely disrupted. Roads and communication networks have been badly hit. However, we as a nation are not new to floods by any means. Temporary shelters are regularly built when floods occur, but it is time to increase their numbers. Similarly, volumes of relief materials must be increased and stored in advance. Reflecting back to the flood situation a couple of years ago, we urge the government to buckle up efforts and prepare for the worst case scenario.
In case the same situation repeats this year, flood-hit people in northern and north-western regions will have to go through immense sufferings. Therefore, ensuring adequate supply of food, pure drinking water and shelters are a must. Moreover, waterborne diseases will become a major concern in the affected areas, especially if shelters are submerged. Special care needs to be taken for children, so as to prevent them from drowning and not get infected with waterborne diseases. We would particularly call on our flood and disaster management authorities to build adequate number of shelters in remote regions. There is no flood shelter in most remote regions, and government's relief assistance hardly reaches the victims there. In order to minimise damage in food production, a damage control mechanism is markedly missing It goes without saying how devastating floods, especially prolonged ones, can be for our farmers And not to forget, during the prolonged floods two years ago crops worth Tk 350 crore had been damaged. A plan should be in place to provide farmers with seedlings immediately after the floodwater recedes and to compensate them for the crop loss.
As floods are turning to be more frequent and bigger in scale, we believe, it must be a priority for the government to strengthen its forecasting and prevention mechanisms. Moreover, adverse effects of climate change are turning recent floods to be unpredictable and longer in duration.
Unless all government agencies work together, it won't be possible to tackle the country's worsening flood situation. The suffering that all this has caused is hard to describe. It's an emergency made worse by both natural and manmade causes.
Also ponds, canals and haors, which once dotted these areas and traditionally served as reservoirs holding the excess water from floods, have all but vanished in recent decades, thanks to mindless development, urbanisation and flawed government policies. Many of the rivers have also been encroached, and consequently dry up during the summer and overflow after above-average rainfall. During a visit, the foreign minister, a lawmaker from the Sylhet-1 constituency, spoke of plans to dredge the rivers to restore their navigability.
This is not reassuring, given the experience of previous dredging initiatives that rarely delivered results. While we hope the authorities will put their heads together to better tackle floods, which are growing in frequency and intensity because of climate change, the immediate challenge is to deliver relief and medicine and restore normal life in the flood-hit areas. We're told that in Sylhet, where about 13 upazilas including the Sadar city were hit, about 150,000 people are living in the dark after several power stations were inundated. About 675 educational institutions were reportedly closed. Meanwhile, although traders have earlier said that there were adequate supplies of food and other essentials in the market, many shops and warehouses remain under water and the supply line disrupted, which may create a food crisis soon. The situation in the remote villages is reported to be particularly dire. We, therefore, urge the government to take urgent measures to tackle the aftermath of the flood. Expecting that the water will soon recede automatically, as the foreign minister has said, is not enough.
What we need is concrete action, starting with ensuring that help reaches the most affected immediately. Relief and medical teams should be sent out to all flood-hit locations and shelters with adequate supplies, and power should be restored as soon as possible. The government should also address the bigger issues affecting the flood situation in the long run. The principal sources of floods are the river floods from the overbank flows of the major river systems, the Brahmaputra, the Ganges and the Meghna, in the monsoon months. Local rainfall floods frequently accompany river floods caused by runoff from Bangladesh’s high-intensity, long-duration precipitation. This huge discharge of water cannot be drained to the Bay of Bengal because of high outfall water levels. The northern and northeastern transboundary hilly rivers are susceptible to flash floods from the adjacent hills in India in the pre-monsoon season between April and May.
The areas adjacent to estuaries and tidal rivers in the southwest and south-central parts of the country experience tidal floods twice a day due to astronomical tides from the Bay of Bengal. Tropical storms in the Bay of Bengal trigger cyclonic storm-surge floods once in a while, affecting around 12,000 square kilometres of coastal land between April and November. The important elements that determine the extent of flooding are the magnitude, synchronisation of peaks and duration of floods. Smaller differences in peaks of major floods can make a big difference in terms of flood-affected areas since it is spreading floodwater evenly over a wide and flat floodplain. As all the flows are drained in the Bay of Bengal only by the lower Meghna river, it takes time and lengthens the duration of the flood.
Also, the synchronisation of peak flows in the Brahmaputra and the Ganges is a major determinant of the extent of flooding in the country. When the peaks of the two rivers coincide, severe flooding occurs as it was the case in 1988, 1998, and also 2004. The country has experienced floods since ancient times but there is an increasing trend in year-to-year variability in the annually flooded area from the mid-1970s. Some very severe floods were experienced in 1987, 1988, 1998 and 2004 and some less severe ones in 1991, 1993 and 1995
There are a few geographical, physiographic, and hydro-meteorological factors responsible for floods in Bangladesh. Another cause of concern is the damage caused by sudden floods due to the failure of flood control embankments. Anthropogenic activities in the form of construction roads without sufficient drainage capacity through them, road alignments transverse to the main drainage paths, blocked drainage channels due to siltation, cross-dams or fishing activities, and inadequately sized drainage sluices are increasing urban floods. Recently, flood events are becoming more severe because of the river-bed siltation, river encroachment and inadequate drainage capacity. Because of urbanisation, people are filling up the wetlands (ponds, beels) which previously functioned as a reservoir for the rainwater in the floodplain. People throw a large volume of solid wastes in the water bodies, and so, the water carrying capacity of the rivers and lakes is decreasing. These are leading to flooding in the localities causing enormous distress to human life. With the increase of population, more and more people are settling in flood-prone areas, leaving them vulnerable.
An analysis conducted with 2001 population census data revealed that some 45.5 million people were exposed to severe and moderate floods. Flood-prone zones are the worst off among different disaster-prone areas in terms of food shortages, the incidence of extremely poor, insufficient income, illiteracy, and a high concentration of wage labourers. Proper management of floods in a country like Bangladesh is a crying need, and the integration of all stakeholders in the management process can achieve a fruitful result. It is also important, however, to understand variability in long-term flood hazards because this information informs development of a variety of mitigation and adaptation measures, including flood protection structures and insurance. Our monsoon seasonal streamflow reconstruction helps extend the short instrumental record to better understand this variability in the Brahmaputra system and provide a more accurate view of long-term hazards and risks. Combined with climate model projections for the 21st century, this work demonstrates that both natural variability and greenhouse warming will likely contribute to a greater likelihood of high-discharge events and risk of flooding. Therefore, we recommend that the basis considered for policy decisions and mitigation scenarios should not be limited to floods similar to those observed in recent decades. Severe and recurrent high-discharge events likely occurred in the past and are expected to occur again with climate change, and these events must factor into future plans.
The writer is researcher based in the UK. He can be contacted at raihan567@yahoo.co.uk
