Huang He (also known as Yellow River) is the second-longest river in China and the sixth-longest river system in the world.
The Huang He River basin is the birthplace of ancient Chinese civilization, and it was the most prosperous region in early Chinese history.
Thanks to the continual elevation of the riverbed, Huang He has caused much misery to the Chinese population by triggering frequent devastating floods, thereby earning the moniker "Sorrow of China”.
Millions of people living in northeast Bangladesh witnessed a devastating pre-monsoon flood this mid-May, the likes of which they have not experienced since a massive deluge in 2004.
Over half of Sylhet's 110 unions are reeling from flood waters as two of the region's major river systems - Surma and Kushiyara – are both overflowing, flooding a huge swath of croplands, homesteads, villages and townships in this division.
In some primary estimates, in excess of a million people have been marooned and life in major parts of Sylhet city, including its satellite township Shahjalal Uposhahar, coming to a halt. Nearly a thousand academic institutions have been closed while authorities opened several hundred makeshift shelters for the people who had to leave their flooded homes.
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Weathermen attributed the sudden and intense rainfall both in the greater Sylhet region as well as the Surma-Kushiyara's catchment region in northeast India for the flooding, but residents in Sylhet say siltation-induced elevation of the beds of both Surama and Kushiyara rivers is a major cause of the deluge.
They say pre-monsoon heavy rain is nothing new for Sylhet, Meghalaya and Assam during this period of the year, but the gradual elevation of river beds and loss of canals and other natural water reservoirs have all contributed to the magnitude of the overflow.
Over the years, people in Sylhet have been hearing of initiatives to dredge the Surma and Kushiyara, but nothing much has materialized. There is documentation in Sylhet City Corporation on how many letters have been dispatched to the Water Development Board seeking interventions over the years, and the Water Development Board's own project update reports show how some of the river dredging projects in greater Sylhet rivers have been overrunning for years with very little progress achieved.
At the height of Sylhet experiencing one of its worst floods in 18 years, Foreign Minister Dr A K Abdul Momen visited the city last week and spoke of taking immediate action to dredge the elevated riverbeds of the Surma and Kushiyara.
"The beds of the two main rivers of Sylhet - Surma and Kushiyara - have been filled. We have plans to dredge the river before the next monsoon," Momen said while distributing relief among some of the flood victims.
Dredging, recovery, and restoration of water bodies crucial
Arifuzzaman Bhuiyan is an executive engineer working at the Flood Forecasting and Warning Centre (FFWC) of Bangladesh, which keeps track of floods and flash floods throughout the year. Speaking from his years of experience, Bhuiyan said it is true that over the past one week or so both the Indian northeast and Bangladesh's northeast experienced heavy rainfalls, but that is not something unusual for these regions.
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"Both the rivers (Surma and Kushiyara) needed to be dredged and natural water flowing canals, chhoras (smaller canals usually flow from the upland valley to the plains carrying water from the hilly springs) and other water bodies needed to be recovered from grabbers. These have to be restored so that residential areas in villages and towns aren't flooded due to the overflow of rivers and canals," he explained.
A Sylhet resident said some parts of the city had fared better than others in the recent floods due to updates to the drainage system in recent years, and other parts of the city’s drainage system also need to be gradually developed.
Rainfall and flood situation
According to FFWC, the Meghalaya, Assam regions of India have experienced in excess of 1,000mm of rainfall over the past one week or so, while the Sylhet region has also had a heavy bout of 400mm rainfall.
On Friday afternoon, Kushiyara at Amalshid (in Sylhet district) was flowing 167cm above danger level, the same river was flowing 58cm above danger level at Sheola (also in Sylhet) while Surma was flowing 94cm above danger level at Kanaighat, 32cm above danger level at Sylhet city and 10cm above danger level in Sunamganj.
FFWC Executive Engineer Arifuzzaman Bhuiyan said there are indications that water levels of both the Surma and Kushiyara would recede within the next two or three days, as precipitation subsides slightly.
Importance of Surma-Kushiyara in Bangladesh's river system
Bangladesh's Surma river, which is called Barak in northeastern India, flows west from the Manipur Hills in the northern Manipur state of India and then southwest into Mizoram state, where it veers north into Assam state and flows west past the town of Silchar.
The river next splits into two branches – Surma and Kushiyara – both of which enter Bangladesh and turn southwest.
The Surma flows past Sylhet in a rich tea-growing valley, while the Kushiyara subdivides into two more branches, both of which rejoin Surma later. At Bhairab Bazar, the river enters the Old Brahmaputra to become the Meghna River, one of Bangladesh's three main river systems.
