Water EQ 2 Flashcards
What are the human contributions to drought?
- Groundwater extraction (aquifers)
- Settlements + Concrete blocking water flow/infiltration
- Climate Change “Enhanced greenhouse effect”
- Channelisation
- Overgrazing
- Desertification
- Deforestation
- Overcropping
What are the physical contributions to drought?
- ENSO cycle
- The tri-cellular model & ITCZ
What are the 4 types of drought?
- Meteorological
- Hydrological
- Agricultural
- Socio-economic
What is meteorological drought?
Long-term precipitation is much lower than normal but there is no consensus on when a water deficit is being declared a drought
What is hydrological drought?
Deficiencies in surface and subsurface water supplies (rivers, groundwater, etc.)
What is agricultural drought?
Insufficient soil moisture to satisfy a particular crop at a particular time.
This can be caused by precipitation shortages, soil water deficits and reduced groundwater/evapotranspiration.
What is socio-economical drought?
Water demand for Social and economic purposes exceeds water availability.
This can come as a result of weather-related shortfall or overuse of existing supplies
What are the 3 different measurements of drought?
- Palmer Drought Severity Index (PSDI)
- Crop Moisture Index (CMI)
- Palmer Hydrological Drought Index (PHDI)
Describe the physical location of the Sahel
Sub-Saharan Africa
What are the physical causes of drought in the Sahel?
- Tropical Convection
- West African Monsoon
- El Nino
- Climate change
What human actions contribute to drought in the Sahel?
- Overcultivated land, overgrazing
- Desertification
- Air pollution, enhanced greenhouse effect
What are some of the consequences of drought in the Sahel?
- Poverty & famine
- No crops, no vegetation cover
- Economic standstill
