Frontal Systems
Weather on a Front. Image by DiyMid. ZIMSEC O Level Geography Notes: Fronts
Fronts
-A front is a boundary between two air masses. Fronts are classified and named according to which air mass is replacing the other.
Warm Front ![A [...]
</p>
</body></html>](https://revision.co.zw/wp-content/uploads/2015/04/image_preview.png)
February 2025
Convectional rainfall
Convectional Rainfall commonly occurs in rainforests. Image by Wallpaperlepi ZIMSEC O Level Geography Notes: Convectional Rainfall
The effects of earthquakes
A tsunami in Miyako Japan 2011/Image credit Ibtimes. ZIMSEC O Level Geography Notes: The effects of Earthquakes.
Factors that may affect the impact of earthquakes.
- Distance of concerned area from epicenter although you should take note of the factor below.
- Coastal locations have a higher risk […]
Mesa and Butte
Messa (left) and Butte (right). Image credit channingchurch.com ZIMSEC O Level Geography Notes: Mesa and Butte
- Mesas and buttes are flat topped uplands with steep sides and often capped by hard resistant rocks.
- Mesas and buttes are desert features created primarily by river erosion […]
Surface Water flow and the origin of rivers
Natural Springs contribute their water to rivers and often form the source of rivers. Image credit paintballfun.com ZIMSEC O Level Geography Notes: Surface Water Flow and the Origin of rivers
Surface water flow and […]
Pressure systems
The world’s pressure belts and winds ZIMSEC O Level Geography Notes: Pressure
Pressure
- Air has weight and therefore exerts pressure, called atmospheric pressure onto the earth’s surface.
- The pressure is not the same for all regions nor is it the same for any one region all the time that […]
The rain-shadow effect
Sem-arid conditions in Save Valley are due to the Rain-shadow effect. Image by Youth Delegates ZIMSEC O Level Geography Notes: Rain Shadow Effect
We have already looked at the formation of relief rainfall elsewhere. The […]
Weathering
A weathered boulder. Image credit earthlearningidea. ZIMSEC O Level Geography Notes: Weathering
- Earth movements (plate tectonics) create and lead to the development of the earth’s major landforms for example block mountains, volcanic cones, lava plateaus and rift valleys.
- As soon as they are formed denudation processes […]
Playas
A playa. Image credit bergoiata.com ZIMSEC O Level Geography Notes: Playas
- These are sometimes known as inland drainage basins.
- Due to the fact that there are no permanent drainage patterns in deserts any rain that falls either evaporates or infiltrates into the soil or runs off and […]
River capture
River capture. ZIMSEC O Level Geography Notes: River capture
- This is a process where one River captures the headwaters on a nearby stream.
- This can occur due to several reasons viz:
- Tectonic earth movements, where the slope of the land changes, and the stream is tipped out of its former course.
- Natural damming, […]