SEE: Water: 5.4A
- Created by: MaggieNaylor
- Created on: 09-03-22 20:42
View mindmap
- 5.4A: The causes of drought
- Drought is when there is a water deficit in a place over a period of time compared to the average rainfall for the same period
- Meteorological drought
- Deficiency in precipitation leads to reduced infiltration, runoff, deep percolation, and groundwater recharge
- Short term precipitation deficit!
- Long term deficit. Caused by things such as El nino events + climate change
- Climate warming leads to increased evaporation
- 2019 'Big Dry' in Australia thought to be as a result of long-term climate change
- Climate warming leads to increased evaporation
- Change from a low to high pressure system which cannot form clouds and therefore causes drought
- Long term deficit. Caused by things such as El nino events + climate change
- Short term precipitation deficit!
- High temps, wind, low humidity, high sunshine, low cloud, lead to increase in evapotranspiration
- Drought in 2000s Australia was made worse by changing air/ocean currents in the Pacific
- Deficiency in precipitation leads to reduced infiltration, runoff, deep percolation, and groundwater recharge
- Hydrological causes
- Streamflow and groundwater levels decrease because of reduced precipitation and high rates of evaporation
- Also results in reduced storage in lakes/reservoirs, decreasing water quality
- Linked to decreasing water supplies for urban areas
- Overtime, agricultural drought can ensue
- Rainfall deficiency leads to soil moisture deficiency, reducing plant growth
- This leads to a poor crop yield
- Rainfall deficiency leads to soil moisture deficiency, reducing plant growth
- ENSO cycles
- El Nino can trigger drought, usually in its 2nd year, in South-East Asia, India, Eastern Australia
- Reversal of trade winds/weakening of them leads to cooler ocean temps, high pressure, and drought conditions
- La Nina can lead to drought conditions in South America
- Cooler than normal ocean temps leads to strong high pressure and to dry conditions and drought
- El Nino can trigger drought, usually in its 2nd year, in South-East Asia, India, Eastern Australia
Similar Geography resources:
Teacher recommended
Comments
No comments have yet been made