Droughts

• Ethiopian Famine (1984) - limited rain in 1983. Grain prices rose by 300% due to low crop yields.
• Ethiopian Famine (1984) - budget and loans spent on the military. Lots of corruption
• Ethiopian Famine (1984) - Affected 7.75m out of the 40m population
• Ethiopian Famine (1984) - 300,000 - 1.2m dead
• Ethiopian Famine (1984) - 400,000 refugees
• Ethiopian Famine (1984) - collectivisation (putting different (normally ethnic) communities together to improve efficiency) sparked insurgency in Northern Ethiopia
• Ethiopian Famine (1984) - drought sensitive region. Sahel is a transitional climate zone
• Ethiopian Famine (1984) - normally 85% of rainfall in the summer
• Ethiopian Famine (1984) - tropical seas favour convection currents over ocean weakening Africa's monsoon.
• Ethiopian Famine (1984) - uncontrolled population growth
• Murray Darling Basin - linked to El Nino cycle
• Murray Darling Basin - increase in water abstraction due to industry and western life style
• Murray Darling Basin - 30% of country affected by drought / year
• Murray Darling Basin - variable rainfall due to being affected by sub tropic high pressure belt
• Murray Darling Basin - since 1970(s), East AU is drier due to shift in rainfall pattern
• Murray Darling Basin - Big Dry was a 1 in 1000 year event
• Murray Darling Basin - heavily impacted wool, meat and wheat exports
• Murray Darling Basin - resovoirs, despite being high tech, fell to 40% capactiy
• Murray Darling Basin - Adelaide drew 40% of drinking from river murray
• Murray Darling Basin - instigated by unsustainable overabstraction
• Drought = an extended period of deficient rainfall relative to the statistical multi year mean of the region.
• Meterlogical drought - low rain, high temps and strong winds. Soil moisture decreases
• Hydrological drought - little percolation, reduced infiltration. Less urban supply, poor water quality, reduced storage in lakes
• Agricultural drought - low evapotranspiration, low biomass and increased plant stress. Low grop yields, irrigation systems fail
• Famine drought - loss of natural veg, increased wild fire risk. Lots of agricultural failure, rural economy collapse, high levels of rural to urban migration.
• Brazil drought (2014 - 2015) - Sao Paulo and Rio de Janiro impacted heavily
• Brazil drought (2014 - 2015) - reliance of HEP - limited electricity so rolling blackouts
• Brazil drought (2014 - 2015) - since 2012, water loss of 28t gallons / year (Nasa) due to drought
• Brazil drought (2014 - 2015) - HEP = 60% country's electricity. It is falling because of droughts.
• Brazil drought (2014 - 2015) - Amazon deforestation - limited evapontranspiration
• Brazil drought (2014 - 2015) - caused by:

  • overabstraction of groundwater led to aquifer levels being too low
• Brazil drought (2014 - 2015) - caused by:

  • Typically, moist air moves westerly and Andes maintains flow of moisture. But in 2014 moist air moved away from the Andes (wet North) and Bolivia had heavy rain
• Brazil drought (2014 - 2015) - caused by:

  • Deforestation reduced levels of moisture in the air
• Brazil drought (2014 - 2015) - rainforest + wetlands services:

  • Regulates ground water recharge, water purification and flood control
• Brazil drought (2014 - 2015) - rainforest + wetlands services:

  • supports nutrients cycle and food chain. also supports tourism
• Brazil drought (2014 - 2015) - impacts:

  • 17 largest resovoirs in Brazil felt to dangerously low capacity
• Brazil drought (2014 - 2015) - impacts:

  • Positive feedback loop - deforestation, less evapotranspiratio, more droughts, more wild fires, more carbon released, amazon eventually turning into grasslands