Changes in the Channel Characteristics of Ganga River During Late Pleistocene - Holocene

Gangetic plain shows distinct geomorphic surfaces formed in response to the climatic and base-level changes related to the sea-level fluctuations during Quaternary. Within the major river valleys, a distinct geomorphic surface (T₁) is developed, located about 5-10 m above the present-day flood plain (T₀). Study of these surfaces in the Ganga River valley near Kanpur demonstrates that T₁ -surface channel deposits assigned tentatively the date of the last interglacial (25-30 Ka) show meandering scars and coarser sediments (M₁ = 1.9 φ) than the present-day channel sands. The T₀-surface shows braided channels and finer sediments (M₁ = 3.4 φ). The Ganga River has undergone a river metamorphosis from meandering to braided-type during the last 25,000 years, accompanied by decrease in grain-size, and probable decrease in water budget and increase in sediment load. All the major rivers of the Gangetic Plain, many of them braided-type today, show evidence of having been meandering rivers during last interglacial (25-Ka).