Social Science (087) — AI-generated practice question

Multi-purpose irrigation projects provide abundant water, encouraging farmers to shift from traditional dry crops to water-intensive and commercial crops (e.g., rice, sugarcane) that fetch higher market returns.

To maximise yield, farmers over-irrigate their fields. Excess water seeps into the soil and raises the water table. As this water table rises to the root zone, it brings dissolved salts upward through capillary action.

When the waterlogged soil is exposed to sun, surface water evaporates, leaving behind a white crust of salts on the topsoil. This process is called salinisation.

Over time, salt accumulation makes the soil hard, alkaline, and infertile, rendering agricultural land unproductive. Thus, a decision driven by profit — choosing water-intensive commercial crops — sets off a chain (canal irrigation → over-watering → rising water table → evaporation → salt deposition) that permanently degrades the land.

Source: Chapter 3 — Water Resources, Multi-Purpose River Projects and Integrated Water Resources Management

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• The key phrase from the textbook is: "Irrigation has also changed the cropping pattern of many regions with farmers shifting to water-intensive and commercial crops. This has great ecological consequences like salinisation of the soil."
• Examiners want the chain/process: crops chosen → over-irrigation → waterlogging → rising water table → evaporation → salt deposition → land degradation. Award marks are split across these logical steps.
• Use the term salinisation explicitly — it is the textbook term.
• Do not mix this up with soil erosion or sedimentation — those are separate problems of dams.