What are Hydrocracies, Hubris and Hazardscapes, the man-made factors that lead to floods in Brahmaputra?
Floods are perennial problems of the North Eastern States. The flood situation due to Brahmaputra river keeps affecting more than 40 lakh residents in Assam.
Due to floods in Brahmaputra river, tea plantations get hit, more than 100 animals of Kaziranga National Park get killed. This happens every rainy season. Most of the areas are submerged mainly due to backflow of the river.
As River Brahmaputra enters India taking a U-turn around Mt Namcha Barwa, it reaches a plain region. The plains are reached suddenly after descending through a steep slope. This forces the river to deposit its silts and sediments. Thus, when there are rains and the water level raise in the river, the river overflows and floods its bank. It also tends to change its direction of flow because of this reason.
Also, more than 50 tributaries flow in to the river that adds to the flow of the river. During summer, the glaciers in the Himalayan region melt and increases the flow. The summers are followed by heavy monsoons that increases its flow further. All these three factors cause the river to flood severely.
Though Brahmaputra floods due to natural reasons, the disasters due to the flooding of Brahmaputra have increased lately due to anthropogenic reasons. They are as follows
The river-infrastructure development projects have become a race. Large Infrastructure projects such as Ranganadi Hydroelectric project in Arunachal Pradesh was pushed in competition with China. Unfortunately, the region experiences dam-induced flash floods during monsoons and for the rest of the year, the river is seen as a trickle.
Another flood control measure being implemented in the state of Assam is “Dredging” activity in the river bed. The extracted river bed material is used in construction of super highways along the banks. This will also facilitate inland navigation. However, this is a superficial solution. This is because, Brahmaputra deposits highest sediment loads and thus the dredging activity will be replenished with fresh silt deposits. It is humanely impossible to desilt Brahmaputra every season for its huge silt being deposited regularly. The removed silt is quickly replenished with new silt.
Construction of Embankments
The Embankments are structures that are built along the river to confine them and to make their flow faster. This monsoon, in 2020, over 180 embankments were breached. More than 450 embankments were built and repaired prior to the monsoon to prevent flooding. This happens every monsoon season. In the last six decades, the Assam Government has built about 5,000 km of embankments along the river and is tributaries.
What is the issue?
The issue is that the embankment points are chosen based on localised floods. Rather, basin-wide floods should be considered.
Brahmaputra is a trans boundary river. It flows through Tibet, India and Bangladesh. In India, it flows through Arunachal Pradesh and Assam. However, the catchment area of the river extends to the states of Arunachal Pradesh, Assam, West Bengal, Sikkim, Meghalaya and Nagaland.
The impacts of the floods of Brahmaputra are studies within a Geopolitical container. This frames a reductionistic understanding and leads to fragmented analysis. An integrated study is required.
Category: Environment Current Affairs