Heavy pre-monsoon rains in India have flushed away railway stations, small towns, and rural areas, displacing large numbers of people as severe weather events such as heat waves, heavy rain, and flooding are becoming more prevalent in South Asia.
The destruction has immersed train tracks and roadways in India's northeast, among the worst hit areas. Floods have impacted 31 of Assam's 33 districts, affecting the lives of over 700,000 people, according to authorities on Saturday. According to news reports, at least 18 deaths were reported in the area as a result of extreme flooding.
Flood events are an annual affair in the Assam state, having a devastating impact annually; let's look at why this happens.
The significant proportion of flood-prone areas in the province is among the primary causes of the state's yearly deluge. As per the Rastriya Barh Ayog (RBA), 31.05 lakh hectares of the state's total 78.523 lakh hectare site is predisposed to flooding. And the causes of this high proportion of flood-prone areas are both man-made and natural.
Topography plays a significant role. The Brahmaputra river is both Assam's source of support and a threat. In terms of runoff and sediment transport, the river tops the list five in the world.
According to The Indian Express, by the time the river reaches Assam ĄĒ a state primarily composed of floodplains encircled by mountains ĄĒ it has deposited substantial quantities of this silt, causing flooding and erosion.
As the river flows from an elevated slope to a flat plain, its velocity drops abruptly, causing the sediment to be unloaded. Again, due to the state's seismic activity, the river has still not developed a steady character.
Even the Brahmaputra river rose by 2 metres in the Dibrugarh region of eastern Assam, post the destructive earthquake of 1950.
It is a vast navigable waterway with numerous channels and water sources that crisscrosses much of Assam. The state? gets both monsoon rains as well as water flowing from the Himalayan range, the largest of which is the Brahmaputra. This ought to be highly favourable, but is no longer considered so. Summer melting glaciers happens to coincide with the rainy season, ratcheting up downstream and resulting in annual flood.
State's flood situation is further compounded because it gets river water from other states such as Arunachal Pradesh and Meghalaya. Another significant source of devastating floods is bank erosion induced by the Brahmaputra River. When there is a deluge, it causes the water to overflow in low-lying regions.
According to the state's official data, between 2004 and 2014, the south bank tributaries of the Brahmaputra in lower Assam underwent flash floods of significant magnitude due to cloud bursts in Meghalaya river basins.
Aside from natural forces, man-made factors such as human settlement, deforestation, and growing populations in watershed areas (including in China) all contribute to increased sediment deposition.
According to reports, as riverbed encroaches, an increasing number of the population are living near the river. Across the state, towns and villages have sprouted up without any suitable disaster response.
The customary slash-and-burn farming practised in state's hilly regions is known as jhum or shifting cultivation.There they burn vegetation that removes land's topmost protective layer, making it more vulnerable to rain erosion. A considerable portion of soil and crop dead material then flow into the river basin and are accumulated.
Assam and some other regions of the northeastern area are also seismically active, which make a significant contribution to landslides. Landslides and earthquakes transfer a large amount of debris in rivers, raising the river bed.
Not to mention the climate change impacts on the Eastern Himalayas, where glaciers are melting rapidly. Annually, the Brahmaputra draws a massive quantity of water, causing flooding.
Earlier, flooding was considered essential to the survival of Kaziranga National Park, which is best known for its one-horned rhinos. It is believed that? flooding rejuvenates the grasslands. Previously, the animals in the park could easily move to higher ground.
However, according to reports, when ninety percent of Kaziranga was deluged in 2019, the water inundated every bit of the sanctuary, including higher ground. The animals eventually had nowhere to go. And the alarming numbers of animal mortalities were 350 animals in 2016, 503 in 2017.
According to a scroll report, aquatic species are also declining as the inflated river and collapsing riverbanks disrupt their ecosystems, and the generation old Mising culture of hand - crafted pottery is also in risk as the sand diminishes the adsorption affinity of the clay, likely to result in weaker pots which fetch lower costs.
Adding on, reports also found that nearly all power plants are invariably located near these river systems since they pull river water to cool down the machine and flush the boiled water drectly into rivers. The flooding disrupted power supply in several districts.
The Brahmaputra Board proposed irrigation infrastructure to mitigate flood events in its strategic framework for the river in 1982.
Dams, however, have proven to be a difficult solution, particularly in flood-prone regions, according to experts. And although they assist to regulate the discharge of flood waters, the discharge can exceed the capacity of the downstream networks.
Meanwhile, the state administration says on its water resources official site that it's been raising and reinforcing embankments, constructing floodwalls, and enhancing village drainage, thereby protecting more than half of the state's flood-prone regions.
Experts add that a "basin-wide strategy" to the issue is required for a long-term remedy. An "integrated basin management" framework that, ideally, would include all basin-sharing nations.
Interstate connections, political cooperation, as well as the role of the state are critical in addressing the issue as a whole, which includes nearby states and countries.
Flood-plain zoning is another proposed solution by experts. This method prohibits specific activities based on the vulnerability of the region, which is divided into categories.
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