Unit 3 Notes Flashcards
What is a water deficit?
Experienced when an area lacks sufficient water to meet its’ needs.
What is a drought?
An extended period of low or absent rainfall relative to the expected average for a region.
What is the UK’s definition of a drought?
15 consecutive days with less than 0.2mm of rainfall.
What is Libya’s definition of a drought?
2 years with no rain.
What does warm air rising mean?
Low pressure - Air cools, condenses, and precipitation occurs.
What does cold air sinking mean?
Air warms, no condensation or precipitation occurs.
What is the case study for seasonal variation of precipitation?
The 1976 UK Drought.
What were the reasons for the 1976 Drought?
Jet stream was positioned further north than normal, high pressure system was located over the UK. UK had a dry winter before 1976 summer.
What were the economic and social impacts of the 1976 drought?
Harder to do daily tasks - people had to go to a stand pipe. Some businesses had to close due to the heat. Domestic water supply was limited to tankers and street pipes.
Which parts of the country were affected the least?
Northern parts of Scotland.
Which areas of the country were affected the most?
South of England and the Midlands - 55% of average rainfall. North of England - 75-85% of average rainfall.
What % of average rainfall did the UK, England, and Wales have as a result of the drought?
UK - 72%.
England - 64%.
Wales - 62%.
Which year had the peak average temperature between 1951-2007?
1976 - 25 degrees.
Which year had the lowest average temperature between 1951-2007?
1956 - 18.5 degrees.
Which year had the lowest number of days of rainfall from 1951-2007?
1976 - 8 days.
Which year had the highest number of days of rainfall from 1951-2007?
1987 - 43 days.
Which areas of Europe have the lowest drought frequency?
North West Europe, such as the UK, ROI, Germany.
Which areas of Europe have the highest drought frequency?
Eastern European countries, such as Hungary and Poland.
What is the case study of a megadrought?
Western USA.
What is a megadrought?
A severe drought, over a decade or longer, covering a wide area.
How much have temperatures increased by in the Western USA since 2000?
1.2 degrees.
Which other factors have made the temperature increase worse?
Climate change and weather patterns such as El Nino.
What are the impacts of the drought?
Increase in wildfires, water shortages, crop failure, food insecurity, reservoirs not refilling, water shortages cost California $3.8 Billion in Agricultural costs.
What are the human costs of water deficit?
Extracting 10x as much water in 2050 as we were in 1900. Population is predicted to be 5x as much as it was in 2050 than it was in 1900. Water use is increasing, as countries become wealthier, grow in affluence.
What is water scarcity?
The lack of available fresh water resources to meet demand.
What is water scarcity increased by?
Climate change, population growth, increased consumption, increased water withdrawal.
How much water does the average home use in a day?
300 litres.
Why is water use in homes so high?
Washing, toilet use, laundry, cleaning, food preparation.
What % of global freshwater is used in agriculture?
70%.
What is green water?
Precipitation that infiltrates into the soil.
What is blue water?
Water in rivers, lakes, and groundwater.
What is the second largest user of water?
Industry - Electricity generation - 19%.