Which of the following has/have shrunk immensely/dried up in the recent past due to human activities ? 1. Aral Sea 2. Black Sea 3. Lake Baikal Select the correct answer using the code given below :

Identifies Lake Aral (Aral Sea) as a classic example of an endorheic (closed) basin where water converges to a sink; such basins are sensitive to reductions in inflow and can become dry lakes.

A student could check a map to confirm the Aral Sea lies in an endorheic basin and then look for evidence that its inflow rivers have been reduced (e.g., by diversion or irrigation) to explain shrinkage.

States that human activities now rival natural agents of environmental change (e.g., changing atmosphere, land/water use), establishing a general rule that humans can cause large-scale changes to water bodies.

Use this general rule plus regional facts (river diversion, irrigation projects) to assess whether human actions could plausibly reduce inflows to the Aral Sea and cause shrinkage.

Lists mechanisms that can dry rivers/lakes: drying of glaciers, river piracy, and shifting river courses—processes that change freshwater supply to downstream basins.

Compare whether the Aral Sea's inflow rivers experienced any of these processes or anthropogenic analogues (e.g., upstream water withdrawals) to evaluate causes of shrinkage.

Provides historical examples of major river course shifts and diversions in the region (Indus and its tributaries), showing that river courses and their downstream destinations can change substantially over time.

A student could locate the Aral Sea and trace historical/current courses of its feeder rivers to test if diversion or course change reduced inflow and led to drying.

Describes how diversion or loss of tributaries led to drying of a major river (Saraswati)—an example linking changes in tributary input to downstream drying.

Analogously investigate whether tributary diversion or upstream water loss occurred for rivers feeding the Aral Sea, supporting a human-caused shrinkage hypothesis.

States Lake Baikal is in an active rift valley and contains roughly 20% of the world's unfrozen surface freshwater, establishing its huge volume and sensitivity as a major freshwater reservoir.

A student could use this to reason that any reported large shrinkage or drying would be exceptional and would require substantial causes (e.g., major diversion, extraction, or climatic change) to remove such a large volume.

Says lakes are temporary features that can be eliminated by draining, silting, evaporation and percolation, and that in unreliable rainfall regions lakes can dry up seasonally.

Apply this general process list to assess whether factors (increased evaporation, reduced inflow, human-driven drainage) could plausibly shrink Baikal by checking regional climate trends and water-use changes.

Describes major human uses of lakes (transport, economy) and implies strong human-lake interactions where lakes matter to societies.

Use this to motivate checking whether large-scale human activities (industrial withdrawal, dams/diversions, pollution) occurred on Baikal's inflows or basin that could reduce its level.

Explains that some lakes (poljes, playas) shrink during dry periods due to seepage and that lake size can be seasonally variable.

Combine this with knowledge of regional hydrology to assess whether seasonal/long-term changes in precipitation or seepage could account for observed shrinkage rather than direct human elimination.

Notes climate change — driven by human activities — can cause large ecosystem and biodiversity impacts, implying human-driven climate factors could alter lake systems.

A student could extend this by checking whether regional climate change (temperature, precipitation) trends around Siberia could reduce inflows or increase evaporation at Lake Baikal.