This topic explores the complex causes of drought, distinguishing between meteorological, hydrological, and human factors, and examines why global atmosphe
Topic Synopsis
This topic explores the complex causes of drought, distinguishing between meteorological, hydrological, and human factors, and examines why global atmospheric circulation makes certain locations more vulnerable to drought as a natural hazard.
Key Concepts & Core Principles
- Meteorological drought: caused by a persistent deficit in rainfall due to atmospheric circulation changes, such as El Niño or shifts in the ITCZ.
- Hydrological drought: occurs when low rainfall reduces river flows, reservoir levels, and groundwater recharge, often lagging behind meteorological drought.
- Agricultural drought: when soil moisture is insufficient to support crops, often due to a combination of low rainfall and high evaporation rates.
- Vulnerability: the degree to which a population is at risk, influenced by factors like poverty, reliance on rain-fed agriculture, and lack of water storage infrastructure.
- Human exacerbation: over-abstraction of groundwater, deforestation (reducing evapotranspiration), and climate change (increasing temperatures and altering rainfall patterns) can worsen drought severity.
Exam Tips & Revision Strategies
- Ensure you can distinguish between the different types of drought causes (meteorological, hydrological, human)
- Use the concept of global atmospheric circulation to explain why specific regions are more prone to drought
- Be prepared to discuss how vulnerability to drought changes over time
- Use specific terminology when describing the human impact on drought (e.g., deforestation, dam building)
Common Misconceptions & Mistakes to Avoid
- Confusing meteorological drought with hydrological drought
- Failing to link global atmospheric circulation patterns to specific drought-prone locations
- Overlooking the human-induced factors (e.g., deforestation or dam building) that exacerbate drought conditions
- Generalizing drought causes without considering the complexity of the hazard
Examiner Marking Points
- Characteristics of arid environments compared to extreme weather conditions associated with drought
- Meteorological causes of drought
- Hydrological causes of drought
- Human causes of drought (agricultural, dam building, deforestation)
- Role of global atmospheric circulation in creating vulnerability to drought
- Temporal changes in drought vulnerability