‘Moribund Delta’ is a subdivision of which of the following Deltas?

The correct answer is C) Bengal Delta. A moribund delta is a part of a delta that has stopped receiving fresh sediment because its main distributary has shifted or silted up. Subsidence and slow erosion take over, and the land no longer builds outward.

In the Ganga-Brahmaputra (Bengal) delta, the western lobe, traversed by the Bhagirathi-Hooghly system, is the Moribund Delta. The eastern lobe, built by the Padma and the Meghna and still prograding into the Bay of Bengal, is the Active Delta. The Sundarbans lies across this landscape.

• A) Krishna-Godavari: Not classified into active and moribund parts in standard geography texts.
• B) Mahanadi: Likewise, no such sub-division is standard.
• D) Cauvery: Its delta is a fertile agricultural tract, not divided on this basis.

For Mains, this links to Ganga water sharing, the Farakka Barrage's effect on Hooghly flow (which accelerates the moribund character of the western delta), Hooghly siltation at Kolkata port, and sea-level rise threats to the Sundarbans.

Trap: Aspirants pick the Krishna-Godavari or Cauvery because they are better known deltas, but the active and moribund classification belongs specifically to the Bengal delta.