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 […]
February 2025
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, […]
Introduction to weather and climate
Rainy Weather. Image by Sodahead. ZIMSEC O Level Geography Notes: Introduction to Weather and Climate
Weather-the state of the atmosphere at a particular place and time as regards heat, cloudiness, dryness, sunshine, wind, rain, etc. The weather is all around us, all the time. It is an […]
Lightining
Lightining. Image by GreenSociety. ZIMSEC O Level Geography Notes: Weather Hazards: Lightining
- Is typically caused by the physical characteristics of cumulonimbus weather conditions.
- As rain drops fall the energy which they have causes a positive charge to develop at the top of a cloud and negative charges to develop […]
Factors affecting weathering
Weathered Limestone rocks. Image credit konfuciuszintezet.hu ZIMSEC O Level Geography Notes: Factors affecting weathering.
- The rate and prvailing type of weathering at any given place is affected by:
- Climate
- Relief
- Vegetation
- Rock type
Climate
- Weathering types are distrubuted according to the prevailing climate of given areas especially when considering.
- Temperature and rainfall […]
Human activities in deserts
Oil drilling in a desert. Image credit Foxoildrilling.com ZIMSEC O Level Geography Notes: Human Activities in Deserts
- In spite of their hostile enviroments brought about by aridity leading to shortage of water, pasture, wood fuel and other wood resources, remoteness, infertile and salty […]
Irrigation Farming
Small scale irrigation. Image credit wfp.org
ZIMSEC O Level Geography Notes:Agriculture:Farming types in Africa:Irrigation Farming
- This is the artificial application of water on land in order to grow crops when prevailing climatic and weather conditions cannot sustain such crop growth.
- This expensive farming system is carried out in order to:
- Increase […]
- Increase […]
The Weather Station
A typical weather station. Image by Stanbachonline. ZIMSEC O Level Geography Notes: Weather Station
-A weather station is a facility, either on land or sea, with instruments and equipment for measuring atmospheric conditions to provide information for weather forecasts and to study the weather […]