Studied by 11 people
an atmos circulation in the equatorial regions of the pacific ocean
warmer water in the western Pacific → causing pow-p, warmer air
cooler ocean water in the east pacific → causing high-p, cooler air
winds blow surface ocean water westward (increase sea lvl). cool deep ocean water wells-up along the west coast of South america bringing deep, nutrient-rich seawater to the surface, allowing fish pop to thrive
ENSO = el nino/southern oscillation
sea surface temperature anomalies in the mid-pacific ocean for 1900-2003
el nino has warm temperature anomalies
seasonally changing air circulation in the world’s tropical n subtropical regions in which summer winds blow from the ocean toward the land, bringing heavy rain inland
in summer, land heats faster than ocean; most ocean flows inland
in winter, winter winds blow from the land toward the ocean, causing drier weather inland
land cools faster than ocean; air flows toward ocean
winter n summer r opp
normally bring 2 months of flooding
agriculture depends on regular monsoon rain
economic disaster occurs when monsoon rains fail
droughts occur if rains do not arrive → no crops = no feeding
decade long drought in the 1930s led to severe drought
soil has no vegetation, so lifted into clouds
dust storms carried away topsoil
meteorological drought
agricultural drought
hydrological drought
→ they r sequential
low soil moisture
inhibits crop germination or growth
may be caused by human activity
insufficient water flows into lakes, streams, or reservoirs
surface-water lvl drop
water table drops
hot, dry weather increases evaporation, causing ground to dry out
dry ground contributes to less moisture to air
plants die, contributes less moisture (evaporation) to air and less shade on the ground
moisture deficiency, relative to avg conditions
compares 2 variables:
water supply from precipitation n reserves
water depletion from evaporation, infiltration, n runoff
allows scientists to visualize cumulative changes over time
2011-2017
devasted crops
inconvenienced millions of peep
killed millions of trees
reservoirs dropped to all-time low lvls
have wet n dry seasons
heavy rain falls during wet season
little/no rain falls during dry season
→ risk of famine
if rain f n intensity drop
reservoirs n streams rapidly dry out
crops n livestocks die as soil dries
densely pop areas r at high risk of famine
poor dev n poverty increases drought risk in africa
horn of africa has been n a drought since 2011
17 million peep face water stress n food insecurity
5.5 million peep have access to only contaminated water
lack of infrastruct n poor security hamper relief efforts
hydrological drought has led to the progressive shrinkage of lake chad, central africa
formerly the world's 6th largest lake
lake chad has decreased by 90% due to climate change, pop growth n irrigation
el nino effect
lack of rain + sever drought
cow death (livestock in general)
poor government intervention
food security at risk
people starving to death
severe natural hazard in many areas of the world often accompanied by famine n starvation
often called a ‘creeping’ phenomena until conditions have deteriorated
costs r more difficult to assess than other hazards
China, 1928: 3 million deaths
NE Africa, 1983:150,000 deaths
Somalia, 2017–2018: Food shortages for 6 \n million
