What Assam needs to control Flood?

A case study with models to lessen the effect of monsoon flood.

While the people from other states are fighting against Corona virus, the people of Assam are dealing with the flood havoc alongwith the pandemic equally. Presently in Assam 33 lakh people are affected from flood over 26 districts and death toll rises to 86. Kaziranga National Park is also submerged in water reporting several animals dying due to this crisis. On the other hand, about 24k people are affected from Covid-19 and death pole rises to 58.

The low lying plain valley of Assam, formed due to continuous running of the mighty river Brahmaputra, is both a lifeline and a threat. There was a time when people used to welcome monsoon, welcome the first flood as it makes the soil more fertile. It is a part of their ecosystem. Earlier, the animals could easily move to higher grounds during flood. But now, most of the grounds are inundated including the higher grounds.

Assam flood has become a catastrophe now. This is something we face every single year during monsoon.

But, what is the reason behind this? Why Assam flood an annual affair?

Reasons:

1. Geographical Terrain:

Assam is one of the India’s most flood prone states. If we look around the map of northeastern region of India, we can see that it is surrounded by Himalayan Mountain Range.

The river Brahmaputra originates in the Angsi Glacier, located on the northern side of the Tibet. It flows eastwards parallelly to the Himalayan reaching Namcha Barwa Mountain in Arunachal Pradesh. From there it takes a ‘U’ turn and takes south and enters Arunachal Pradesh where it is called the river Dihang. The Dihang flows down and enters Assam with high intensity and high speed. Also, after entering Arunachal Pradesh the river Brahmaputra or Dihang turns into the greatest channel of small rivers.

During summer, glacier melts which coincides with monsoon. For this reason, when it rains heavily, water level intensifies, flowing towards the low lying Assam valley. Along with this there are several drains which join the river Brahmaputra, rising the water above the danger mark.

2. 1950s Massive Earthquake:

The Brahmaputra river has an unstable water flow. In 1950, an earthquake raised the river bed, making it shallow, causing more flood intensity. As such, the river could not sustain the immense volume of water which causes flood every year.

Moreover, the river tends to change its route periodically, flooding new regions every year.

3. Human Made Cause:

A] Deforestation: In the last few years, we have witnessed major flood issues due to the cutting of wide range of trees and forests. People have started constructing buildings, factories, houses on the floodplains due to which the water doesn’t have space to flow freely, which cause more soil erosion, flooding etc.

B] Improper construction of embankments: Improper construction of river embankments is a serious issue in Assam. Because whenever you try to restrict the flow of water, the speed, intensity and sedimentation increases which if not maintained properly, will cause “embankment breaching”. In Assam, there are about 450 embankments on the banks of the river in vulnerable conditions.

What Could Be The Solutions For This?

1.“Room for River ” Project (Netherlands):

Netherlands is the best country regarding flood control. They initiated a flood control program called “Room for River Project”. They examined the pattern of the water flow and constructed their infrastructure accordingly. They built embankments far away from the rivers, letting the river flow freely. Also, they started to plant more trees and forests beside the embankment. Along with this, they lowered the level of floodplains which provided more room to the river to flow.

Hence, Maintenance of the embankment and flood plain area must be given more attention to resolve this problem.

Image Source- Google |Image by- dutchwatersector

2. Develop a Sponge City (China Model):

The concept of Sponge City is retention of water and reuse of rainfall. This technique includes rooftop garden, permeable infrastructure of road which absorbs the water and that water would be collected and reused for other purposes like rainwater harvesting, rain garden etc. Implement of Sponge City concept can reduce the frequency of flood.

Image Source- Google | Image by-Faith Chan

3. Floating garden model of agriculture (Bangladesh case study):

Water hyacinth is used in Bangladesh to practice agriculture in flood affected areas or in water bodies. This project is called ‘floating garden’.

Farmers make heap with water hyacinth, which decays and make fertilizers for cropping. Many crops grow on these heaps which float in water bodies like floating fields, thus decreasing the loss of agriculture production by flood.

Image source- thedailystar

4. Information of flood focuses must reach to affected areas earlier (Orissa Model):

All of these must be addressed and must be implemented. Otherwise, again we’re going to have the same discussion next year on how to control ‘Assam Flood’.

Photo credit: Rajanav_kalita, Prateek_agarwal, Kausik_rajkhowa, Asif_Iqbal_Khan