HKDSE Geography/M5/Farming Inputs in the Sahel

Physical Inputs

Factor	Characteristics
Climate
Sunlight/Insolation	Abundant
Temperature	High, AMT 28 C
Annual range of temperature	Small, 15 C
Wind	Serious
Relative humidity	Low
Rainfall	Scanty (around 250-500 mm on average) and variable; much seasonal variation
Soil
Soil fertility	Low
Soil acidity	Alkaline
Soil texture	Highly coarse, porous and permeable
Soil moisture content	Very low
Relief
Altitude	Low
Aspect	/
Slope gradient	Gentle
Drainage
Rivers	Very few; only drained by River Niger and River Nile

Pastureland is limited since the carry capacity of the land is low.

Note on climate

• The Sahel has a semi-arid climate.
• Affected by high-pressure belts (subtropical highs), they face sinking air. The air diverges to form offshore winds. There is thus a loss of moisture. High pressure leads to a lack of uprising air and thus scanty rainfall.
• As it is an inland location, it lacks the mediating effect of seawater, so it is very hot in summer. Intense solar radiation creates a high evaporation rate, which reduce soil moisture, hindering crop growth.

Cultural Inputs

Factor	Description
Infrastructure and amenities	Poor
Technology level	Primitive
Labour input	Low
Education level	Low
Transport networks	Poor
Market	Nil (Subsistence farming)
Capital	Very little
Government support	Limited