Lesson 5 - Drought Flashcards
Define the term teleconnections?
Climatic anomalies which relate to each other at large distance. Teleconnections mean that the development of the ENSO within the Pacific Ocean has an impact upon climates around the World.
Define the term humboldt?
A cold northbound ocean current, flowing up the west coast of South America.
Define the term thermocline?
The sharp boundary between the cold deep water and the warmer upper layer.
What is the UN definition of a drought?
A drought is an extended period, a season, year or several years of deficient rainfall relative to the statistical multi-year average for a region.
What is a meteorological drought?
Occurs when long term precipitation is much lower than normal, but there is no consensus regarding the threshold of the deficit or the minimum duration of the lack of precipitation that turns a dry spell into an official drought.
What is an agricultural drought?
Occurs when there is insufficient soil moisture to meet the needs of a particular crop at a particular time. It is caused by a number of factors such as precipitation shortages, differences between actual and potential evapotranspiration, soil water deficits and reduced groundwater or reservoir levels.
What is a hydrological drought?
It occurs when there are dificiencies in surface and subsurface water supplies as measured in rivers, reservoirs, lakes and groundwater.
What is a socio-economic drought?
Occurs when the water demand for social and economic purposes (such as crop irrigation or hydroelectric power) exceeds water availability. This could be the result of weather related shortfall in water supply or the overuse of the available water supplies.
Why is a meteorological drought region specific?
It is region specific since the atmospheric conditions that result in dificiencies of precipitation are highly variable between climate types.
How does socio-economic drought differ from the other types of drought?
If differs from the other types of drought because its occurrence depends on variations of supply and demand.
