Question 349

Reading Comprehension Passage: The perennial inundation of the Brahmaputra valley in Assam has historically been understood through the lens of hydrological fatality—a natural consequence of a hyper-braided river system navigating a seismically active, sediment-rich terrain. However, the catastrophic severity of recent floods has compelled a paradigm shift in environmental discourse, revealing a complex matrix where anthropogenic interventions severely amplify meteorological anomalies. While the intensification of the Indian summer monsoon, driven by global climate change, has precipitated localized cloudbursts and erratic cloud-to-ground precipitation regimes, the true multiplier of this ecological disaster lies within the structural degradation of the river basin's natural hydrological defenses. For decades, the state’s primary flood-mitigation architecture has leaned heavily on traditional structural engineering, notably the construction of extensive longitudinal embankments and levees. This artificial confinement of the Brahmaputra and its tributaries has paradoxically exacerbated the crisis. By restricting the river’s lateral spill, embankments prevent the natural dispersal of heavy silt across the floodplains. Consequently, sediment settles within the riverbed, progressively elevating the channel floor above the surrounding human settlements. When extreme rainfall events occur, these elevated water bodies breach or overtop their artificial barriers with hydraulic ferocity, transforming what would have been a gradual seasonal inundation into a high-velocity, destructive flash flood. Furthermore, aggressive deforestation in the upper catchments of Arunachal Pradesh and the rapid encroachment upon wetlands—locally known as beels —have systematically dismantled the region’s natural ecological buffers. In their pristine state, these extensive wetlands functioned as dynamic hydrological sinks, absorbing surplus runoff during peak monsoon discharge and slowly releasing it during dry spells. Unregulated urbanization and agricultural expansion have choked these natural reservoirs, stripping the valley of its vital sponginess and forcing unbuffered surface runoff directly into the swollen drainage network. The disproportionate human and socio-economic toll of these floods underscore the inadequacy of reactionary disaster management. While immediate evacuation and relief operations remain vital, they merely address the acute symptoms of a systemic socio-ecological breakdown. Contemporary hydro-geological consensus advocates for a transition toward "living with floods"—a nature-based framework that de-emphasizes rigid engineering in favor of wetland rejuvenation, strategic embankment decommissioning, and floodplain zoning. Only by restoring the river’s lateral connectivity and respecting the ecological carrying capacity of its floodplains can Assam hope to mitigate the catastrophic impacts of an increasingly volatile climate regime. What can be reasonably inferred from the passage regarding the wetlands (beels) of Assam?

Answer

Their conservation and restoration would reduce the velocity and volume of floodwaters reaching human settlements during extreme rainfall.

Why?

The correct answer is Option 1 . Key Points Option 1: Their conservation and restoration would reduce the velocity and volume of floodwaters reaching human settlements during extreme rainfall. This is correct . The passage explains that wetlands (beels) function as natural hydrological sinks by absorbing excess runoff during peak monsoon periods and releasing water gradually during dry periods. Therefore, restoring these wetlands would help reduce the intensity and speed of floodwaters reaching populated areas. Option 2: Their transformation into agricultural land has successfully mitigated the hydraulic ferocity of flash floods in urban areas. This is incorrect . The passage states the opposite: wetland encroachment for agriculture and urbanization has destroyed natural flood buffers, increasing unregulated runoff and worsening flood conditions. Option 3: They were artificially engineered by disaster management authorities to act as longitudinal barriers against sediment deposition. This is incorrect . The passage describes wetlands as natural ecological systems , not artificial structures. Longitudinal barriers refer to embankments, not wetlands. Option 4: They are the primary source of the heavy silt that elevates the channel floor of the Brahmaputra River. This is incorrect . The passage attributes sediment accumulation in the river channel to the restriction of lateral spill caused by embankments, not to wetlands. Therefore, the correct answer is Option 1: Their conservation and restoration would reduce the velocity and volume of floodwaters reaching human settlements during extreme rainfall. Additional Information Wetlands (beels) act as natural flood-control systems by storing excess water and gradually releasing it, reducing sudden surges in river discharge. The passage advocates wetland rejuvenation as part of a nature-based approach to flood management, replacing excessive dependence on artificial engineering solutions.