Question

Give reasons for the following.

The distance between Shillong and Cherrapunji is less than 35 km. Yet Shillong doesn’t receive even half the rainfall received by Cherrapunji.

Answer 1

1. Windward versus leeward: Moist monsoon winds from the Bay of Bengal are forced up the Khasi hills on the windward side, cool and condense, producing very heavy orographic rainfall at Cherrapunji (and nearby Mawsynram). Shillong, just over the ridge on the leeward side, lies in the rain‑shadow and receives far less precipitation.
2. Local hill shape and trapping: The Khasi hills around Cherrapunji act like a funnel that concentrates and traps moisture‑laden air, intensifying rainfall there compared with nearby locations.
3. Sharp horizontal change possible: Orographic rainfall can change dramatically over short horizontal distances when a ridge is encountered, so a 30 - 35 km separation can still produce differences of many times in annual rainfall. The regional data show Cherrapunji’s totals are several times those of Shillong.