ZIMSEC · Form 5 · Lower 6
Geography
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- Hydrology and fluvial geomorphology Inputs (precipitation), stores (interception, surface, soil moisture, groundwater, channel), flows (throughfall, stemflow, infiltration, overland flow, throughflow, percolation, groundwater flow) and outputs (evapotranspiration, runoff).
- Atmosphere, weather and climate Incoming solar radiation (insolation) is absorbed, reflected (albedo) or scattered; the Earth radiates long-wave energy. The greenhouse effect traps outgoing radiation. There is an energy surplus in the tropics and a deficit at the poles, transferred by winds and ocean currents.
- Rocks, weathering and tropical landforms Constructive, destructive and conservative margins; the East African Rift Valley shows continental rifting. The Zambezi valley lies in a rift-faulted trough.
- Ecosystems, soils and biomes Energy flows through trophic levels; nutrients cycle between biomass, litter and soil (Gersmehl's model). Net primary productivity is high in tropical rainforests and moderate in savanna.
- Population dynamics and migration Natural change = births − deaths; total change also includes net migration. Measures: crude birth and death rates, fertility rate, infant mortality, life expectancy, dependency ratio.