ZIMSEC O Level Geography Notes: Relief rainfall
- Results when near saturated, warm maritime air is forced to rise by a coastal mountain barrier.
- Mountains reduce the water holding capacity of the rising air by enforced cooling.
- In Zimbabwe it mostly occurs in the Eastern Highlands in areas like Chimanimani, Honde Valley and Nyanga.
- Warm South East Trades pick up moist from the Indian Ocean.
- They encounter a barrier mountain that is parallel to the coastline for example Mt Inyangani and the Chimanimani mountains.
- The SE Trades are forced to rise by the mountain, cool and condense and rain occurs on the South Eastern slopes or the windward slopes of the mountain.
- On the leeward side of the mountain it is dry.
- The descending SE trades are dry and warm resulting in little to no rainfall.
- The leeward side is sometimes known as a rain shadow area. Examples include Save valley and Marange area.
- Relief rainfall occurs in all altitudes
- Most of the rain occurs on the East side of the slope.
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