Consider the microclimatic moisture distribution across the Western Ghats transect in Kerala: Assertion (A): The windward western slopes experience abundant rainfall throughout the monsoon season, whereas the immediate eastern lee slopes suffer a sharp precipitation deficit. Reason (R): As moisture-laden maritime air masses are forced to ascend the steep topographic barrier, they undergo adiabatic expansion, cooling, and condensation, leaving little moisture for descent on the leeward side. Which of the following is correct?

💡 Solution & Explanation

Both the assertion and reason are correct and logically linked. The Western Ghats act as a massive orographic barrier to the southwest monsoon winds. When saturated air is forced upward, it cools at the saturated adiabatic lapse rate, producing heavy orographic precipitation on the western slopes. By the time air crosses the crest and descends the eastern slopes, it undergoes compressional warming and dries out, creating a distinct rain-shadow zone. This meteorological process governs the distinct vegetation zones found on either side of the Ghats.