OCR B GCSE Geography Revision

Revision materials to support you in preparing for your GCSE Geography exams.

Flashcards

Quiz

What are the causes of drought?

A range of human and physical factors can lead to drought. These are summarised below.

Physical Causes of Drought
High pressure systems, often associated with stable and dry conditions, prevent the formation of clouds and precipitation, leading to prolonged dry periods.
El Niño events disrupt normal weather patterns, often leading to reduced rainfall and drought conditions in various regions around the world.
Rising global temperatures intensify evaporation rates, decrease soil moisture, and exacerbate drought conditions in already dry regions.
Shifts in the ITCZ can alter rainfall distribution, causing some regions to experience prolonged dry periods while others receive more rainfall.
Construction of dams can alter natural water flow, reducing downstream water availability and contributing to drought conditions in regions reliant on these water sources.

Human Causes of Drought
The removal of trees reduces the ability of the land to retain moisture, disrupts the water cycle, and leads to reduced rainfall and increased risk of drought.
Over-exploitation of soil and water resources for high-yield crops can deplete water supplies and degrade soil, contributing to drought conditions.
Over-irrigation depletes water reserves, lowers water tables, and can lead to soil salinization, reducing the availability of water for agriculture and other uses.
Overgrazing by livestock removes vegetation cover, leading to soil erosion and reduced soil moisture retention, increasing susceptibility to drought.
Construction of dams can alter natural water flow, reducing downstream water availability and contributing to drought conditions in regions reliant on these water sources.