Explanation: Drainage density = total length of all streams in a basin divided by the basin area (km/km²). It indicates runoff potential and landscape permeability.

Explanation: Dendritic (tree-like) patterns form where rock type is uniform and slope is relatively even, allowing tributaries to branch freely.

Explanation: A watershed (or divide) is the high-ground boundary that separates neighbouring drainage basins.

Explanation: Radial patterns radiate from a central high point like a volcano or dome where streams flow outward in all directions.

Explanation: Godavari is a Peninsular river originating in the Western Ghats; Ganga, Brahmaputra and Yamuna are Himalayan (or Himalayan-fed) systems.

Explanation: Peninsular rivers are not glacier-fed and therefore depend largely on seasonal monsoon precipitation causing variable flows.

Explanation: The combined sediment deposition from the Ganga and Brahmaputra creates the large deltaic region around the Bay of Bengal.

Explanation: Many west-draining peninsular rivers like Narmada and Tapti are seasonal; they originate on the plateau and are not glacier-fed.

Explanation: The Ganga originates from the Gangotri glacier as the Bhagirathi which later joins Alaknanda to form the Ganga proper.

Explanation: The Chambal joins the Yamuna (which is itself a tributary of the Ganga) from the right bank of the Yamuna system — but in Ganga's tributary context, Chambal is considered a right-bank tributary of the Yamuna branch; this question tests knowledge of tributary sides and major tributaries—Chambal flows north-east then east joining Yamuna on its right bank.

Explanation: The Brahmaputra originates in Tibet (as the Yarlung Tsangpo) and enters India through Arunachal Pradesh.

Explanation: The Brahmaputra carries high sediment loads and has highly mobile channels causing frequent floods and severe bank erosion in Assam.

Explanation: Godavari has a large drainage basin and long course in peninsular India, comparable in importance (for irrigation and navigation) to the Ganga in the north.

Explanation: Narmada and Tapti flow westwards in rift valleys between the Vindhya and Satpura ranges and empty into the Arabian Sea.

Explanation: Hirakud dam on the Mahanadi in Odisha is one of the major reservoirs for flood control, irrigation and power in eastern India.

Explanation: Chilika is a large brackish-water lagoon on the Odisha coast, connected to the Bay of Bengal and supporting rich fisheries and migratory birds.

Explanation: Wular is a tectonic lake formed by earth movements; it also acts as a flood basin for the Jhelum river system.

Explanation: Delta regions have fertile alluvial soils and water availability, making them ideal for intensive agriculture like rice and jute.

Explanation: Dams help storage and power but do not permanently prevent river pollution — pollution requires treatment and source control.

Explanation: Untreated sewage from urban areas is a major contributor to river pollution, causing health risks and ecosystem damage.

Explanation: Nutrient overload (fertilizer runoff) leads to algal blooms and oxygen depletion — eutrophication — harming aquatic life.

Explanation: Local clean-ups, waste segregation and reduced plastic use help keep rivers cleaner and prevent solid waste entering water bodies.

Explanation: IRBM coordinates water use, land management and ecosystem protection across the basin for sustainable outcomes and conflict reduction.

Explanation: Check dams slow water, promote infiltration and recharge groundwater while reducing peak flows downstream.

Explanation: The Marble Rocks gorge is on the Narmada near Jabalpur (Bhedaghat) — a tourist attraction formed by erosion through marble/limestone.

Explanation: Godavari rises in the Western Ghats near Nasik (Maharashtra), flowing eastward across the Deccan plateau.

Explanation: Nagarjuna Sagar is a major reservoir on the Krishna river used for irrigation and power across Andhra Pradesh and Telangana.

Explanation: Riparian plants stabilize soil, reduce erosion and provide habitat; hard engineering may be needed selectively but vegetation is ecologically beneficial.

Explanation: Oxbow lakes form when a river meander is cut off from the main channel by deposition, leaving a crescent-shaped lake.

Explanation: Dams trap sediments, alter flow regimes and can block fish migration, affecting downstream habitats and nutrient transport.