RIVER BANK EROSION DISPLACES MILLIONS IN ASSAM

MONOJ GOGOI 

Massive river bank erosion in Assam has been  displacing hundreds of thousands families across the state over decades since India's Independence in 1947. In recent years,  the intensity and frequency of floods and erosion have also been increasing in the state.

A photo of the IAG meeting in Lakhimpur.

According to experts the behavior of rivers in Assam changed just after the Assam Earthquake of 1950 which was measured 8.7 in the Richter scale. The earthquake and the aftershock elevated the river beds of all rivers in Assam. Some rivers including  Subansiri changed channels during the earthquake. It is estimated that since 1950 about 4.27 Sq km of land has been eroded by the Brahmaputra and its tributaries in Assam. In a recent statement CK Das, former Additional Chief Secretary of the state said that the size of the land that fell in river bank erosion would be about 5000 Sq km. But it is believed that the furious fast flowing rivers eroded mass more lands displacing more than two million people across the state. Due to erosion, people lost their houses, fertile agricultural lands, public institutions including schools, healthcare centers, religious institutions, community halls etc to the rivers.

The financial condition of many affluent families affected by erosion became disastrous. In erosion prone areas, sometimes a single family is displaced multiple times. In some severe erosion prone areas, river bank erosion occurs upto 500 metre in a single season. But it's for sure that river bank erosion occurs almost equally in both the seasons. 

Landslides in Arunachal Pradesh's hills 

As mentioned above, the Assam Earthquake of 1950 is one of the primary causes of river bank erosion. 

The health of the hills determines the health of the plains. Here in Assam it's noticed that the fragile hills of Arunachal Pradesh are highly susceptible to landslides. This has been intensified by the development activities, such as construction of roads, highways, dams, urbanization etc, in the Arunachal Pradesh hills. Rampant human greed denuded the hills in the upper reaches of the rivers which increased the sediment and debris in the rivers resulting in massive river bank erosion in the plains of Assam. The depth of the riverbeds decreased substantially which compelled rivers to become wider and flowing in multiple shallow braided channels.

Excessive extraction of resources like  boulders, sands, sand gravels etc from river beds also makes rivers more ferocious for river bank erosion. 

Developmental activities like construction of dams and other structures on rivers also pose threat to erosion prone areas.

Photos: SDRF personnel exhibit how waste materials can be used for making life saving floating tools like life jackets, boats etc to use during floods.

Various structural and non-structural measures are addressed to control river bank erosion. Vetiver, bamboo plantation, mangroves plantation etc are used to reduce risk of erosion; awareness among communities is also emphasized. 

Besides these, the government has been spending millions of rupees each year to prevent erosion by building embankments, spurs, porcupine etc in erosion prone areas but in vain. The structures must be scientific and erected on desired location. 

Knowledge and experiences of local people are often ignored during planning and policy-making. 

Climate change impacts are discernible in the northeast region of India which also deteriorates the erosion situation. Hydrological cycle becomes more unpredictable in the region. High amounts of rainfall occurs in a short term which vehemently increases the erosion situation in certain areas. Prolonged dry-spells in winter reduces the soil moisture in river banks which can be considered as one of the causes of accelerated erosion. 

The north bank tributaries cause more floods and river bank erosion than the tributaries of south bank tributaries as the north bank tributaries are more fast flowing as these originate in Arunachal Pradesh or flow through the hills of Arunachal Pradesh. 

The Brahmaputra itself creates massive erosion in several places in its course in Assam. Lands in Rohmoria, Majuli, Palashbari etc are eaten faster by the river but it doesn't mean that erosion is not taking in other places. Erosion widens the breadth of the Brahmaputra up to 24 km in some places.

Also read: Assam Earthquake 1950

A collective and collaborative approach is very essential to address the issue properly. 

Photo: IAG meeting in Lakhimpur.

Today an Inter Agency Group (IAG) meeting was organized in Lakhimpur by an NGO People's Action for Development (PAD) to discuss flood and erosion problems of Assam. In the meeting was presided over by Papori Borah, the District Project Officer of Lakhimpur District Disaster Management Authority (DDMA) and participated by representatives of various NGOs, officials of concerned government departments and Village Disaster Management Committees (VDMCs). The problems  were widely discussed and emphasized that all the groups must work collaboratively; and the Arunachal Pradesh government should also be brought  to such discussions so that both the governments can co-work for reduction of their respective problems.