Causes of drought

High pressure anticyclone of dry stable, warm, descending air can sit over a large area for long periods and lead to a lack of rainfall.

• Poor farming practices

• weather patterns

• climate change

• ENSO

Overcultivation of crops may use up local water supplies. Growing of cash crops for export can lead to groundwater depletion.

• overabstaction

• deforestation

• ENSO

• Poor farming practices

The fluctuation of climate patterns in the Pacific can lead to drought in Australia and much drier conditions across Southeast Asia

• Climate change

• weather patterns

• overabstraction

• ENSO

This can cause people to migrate to marginal areas with less rainfall and less water availability.

• Poor farming practices

• Conflict

• Deforestation

• weather patterns

distance from the sea, altitude and relief all play a part in the level of moisture an area receives.

• Climatic factors

• Weather patterns

• climate change

• ENSO

removal of groundwater from wells and aquifers can reduce available water supply, which makes drought more severe.

• conflict

• overabstraction

• poor farming practices

• deforestation

This changes the local hydrological cycle and leads to an increase in surface run-off and soil erosion.

• Conflict

• overabstraction

• deforestation

• climate change

warming of the atmosphere is leading to changes in rainfall patterns, with places in already and areas becoming drier, for example in Sub-Saharan Africa.

• weather patterns

• climate change

• climatic factors

• deforestation