Give geographical reason : Mountainous regions are sparsely populated.

Answer: Rugged relief, cold climate and lack of economic opportunities make mountain regions unattractive for settlement.

• Steep slopes and uneven land make construction of houses, roads and railways difficult and costly.
• Thin, infertile soils and steep slopes limit agriculture; only small patches can be cultivated.
• The climate is cold, with snowfall and low oxygen at high altitudes, which is harsh for human life.
• Transport and communication are poorly developed, so industries, trade and services do not grow.
• Hazards like landslides and avalanches are common. Hence the Himalayas, Andes and Rockies have low population density.