Linda Rousseva
08.12.2013
Report: Water and Change
1. Describe and include a map locating water scarcity
2. Define physical water scarcity and economic water scarcity
3. Physical causes of scarcity
4. Human causes of scarcity (which of these are economic scarcity)
5. Generally what methods are available to deal with these problems
6. Case study (either make lots of little case studies or 2 larger case studies one
Physical and one Human scarcity)
Linda Rousseva
08.12.2013
1.
(Water Scarcity)
 Physical water scarcity mostly found
o Around Tropics of Cancer & Capricorn; 30-35˚ North and South
 Southern USA & central America
 North Africa
 Middle East and central Asia (including India and N China)
o South Africa and south eastern Australia
 Economic water scarcity mostly found
o In and around the equator
 Mainly in Central Africa
 West coast of South America
 Central and Western India
 Southern China
2. Physical water scarcity: The physical absence of water, “when the water resources
cannot meet the demands of the population” (“Map Details Global Water Stress”).
Economic water scarcity: There may be plenty of available water, but it is potentially
unaffordable for the population, or it costs too much money to make it safe drinkable
water. It “occurs due to a lack of investment and is characterised by poor infrastructure and
unequal distribution of water” (“Map Details Global Water Stress”).
Linda Rousseva
08.12.2013
3. Physical causes of water scarcity:
 Arid regions:
o Regions of high atmospheric pressure  sinking air in the Hadley cell warms
and dries  no clouds, therefore no rain ("The Causes and Distribution of
Deserts.")
o Areas with >250mm rain per year
o Mainly around Tropics of Cancer and Capricorn (30˚ N and S of the Equator)
Linda Rousseva
08.12.2013
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Rain shadows:
o When moving air reaches a
mountain is rises and cools 
precipitation  the other side of the
mountain stays dry (Rain Shadow
Effect)
Climate change and variability
o Drought
o Severe flooding
4. Human causes of water scarcity:
 Population growth
o Leads to growing demand
 Land use
o Food production (deforestation)
 Agriculture e.g. crops like rice and cotton which require a lot of water
to be grown
 Grazing
o The reduction of vegetation in an area can lead to more surface run-off and a
reduction in groundwater infiltration
  Draining an area of water
 Pollution of water
o As water becomes more scarce and more of it is used, there is a smaller
dilution factor, therefore the pollution in the water becomes more
concentrated
o Water contamination due to
 Agriculture
 Industry
 Domestic uses e.g. sewage
5. Methods available to deal with human water scarcity: (Coping with Water Scarcity.)
 Investments in water supply, sanitation and management
o E.g. LIFESAVER® systems, which are highly effective water filters (relatively
low-cost), and allow populations to stay in place to e.g. rebuild after a flood,
rather than have to move to camps and rely on imported bottled water
 Managing wastewater and pollution control
o Not dumping it in places where it cannot be re-used e.g. the sea
o Using it for agriculture i.e. irrigation because it is rich in plant nutrients
o Putting in place low-cost primary and secondary treatment ("Introduction to
Wastewater Treatment Processes.")
 Primary treatment:
 Mechanical treatment to remove suspended solids
o Removes 50-60% of suspended solids
o Reduces BOD (biological oxygen demand, i.e. how many
organisms are living in the water) by 20%
Linda Rousseva
08.12.2013
Secondary treatment:
 Biological treatment to remove dissolved organic matter by
undergoing aerobic respiration to convert organic molecules
into carbon dioxide, water and energy
o 85% of suspended solids and BOD are reduced
Desalination of sea water
o Increasingly affordable due to development of technologies
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Methods available to deal with physical water scarcity:
 Transferring water from water-rich to water-scarce basins to reduce local
imbalance; see LV case study below
6. LAS VEGAS AND THE GREAT BASIN
AQUIFER Case Study: (Garrington, Sally)
 Physical water scarcity
 Aquifer: an underground storage of
water in permeable rock layers
WHAT & WHERE:
 Arid southwestern USA
o In rain shadow because
surrounded by Sierra Nevada
Mountains and the Rockies
o Mohave Desert (NevadaCalifornia) and the Great Basin
(central Nevada)
o Las Vegas – southern Nevada
PROBLEMS & CAUSES:
 Area has suffered drought since 1999
o 1999-2009 Colorado River’s flow: 66% of normal
 Southern Nevada relies on this for 90% of its water
o Lakes Mead & Powel: only 52% full
o Las Vegas
 Desert climate: 114mm rain/year and 40˚C max. temperature
 High water demand due to increased population because of:
 Immigration
o Land available for agriculture, grazing, military tests
o Mining minerals in the deserts
o Constructing and maintaining dams for water supply
o Electronic industries (clean, dry air)
 Tourism e.g. Grand Canyon
 Climate change may be a cause, because:
o Rain-bearing winds track further north
o Average temperature has increased over last 25 years
Linda Rousseva
08.12.2013
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Population increase in the area  higher water demand
Over-extraction of the water
Nevada still allowing new developments e.g. 120 000 new homes and 6 new golf
courses
SOLUTIONS:
 Water conservation, but more money spent on developing new water resources
o Alburquerque: reduced consumption by 33% 1993-2001
 $1 million budget for publicity & education  water efficiency &
conservation
 Tariffs for water so that more used = higher cost
 Free water-use assessment for households & businesses
 Rebates for efficient dishwashers, low-flush toilets, desert- rather
than turf-landscaped gardens
 Water regulations, especially in drought
o Las Vegas:
 Recycling water e.g. for golf courses
 Watering
 Only before 11am and after 7pm (lower evaporation rates)
 1 day/week in winter and 3 day/week in spring & autumn
 Car washes: collect, clean & reuse water
 1986 - The Great Basin National Park
o Centered on Wheeler Peak  snow provides water for the Basin
 Building a third, deeper intake pipe taking water from the Colorado River
 Controversial: Southern Nevada Water Authority (SNWA) pipeline
o To be finished 2015, pumping 293 billion liters/year
o 485km long with 34 groundwater wells, 3 pumping stations, 6 regulating
tanks, 1 storage reservoir (180 million liters)
o Cost: $5 billion, so far $78 million spent buying up land & water rights
o Problem = area that water will be pumped out supports family ranches and
important ecosystems with xerophytic plants which will die 
desertification  dust storms due to strong winds  pollution & spreading
desertification
BANGLADESH Case Study: (Mbugua,
Alice)
 Human/Economic water scarcity
WHAT & WHERE:
(Image: Ptel)
 Tropical climate because of
Himalayan Mountains in north
o Warm & humid: average
temperature is 26˚C and
Linda Rousseva
08.12.2013
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average annual rainfall is 2540mm
External rivers  92% water in Bangladesh
o Brahmaputra: 67%
o Ganges: 18%
o Meghna and other minor rivers: 15%
Local rainfall  8% water in Bangladesh
PROBLEMS & CAUSES:
 Climate change  rise in global temperature & drop in rainfall, increased extreme
weather, changing patterns  increased diseases, water scarcity
o Change of Monsoon direction from heading North to heading East
o 19 drought periods 1960-1991
o 1˚C rise in average May temperature 1985-1998
o 5˚C winter 2007: lowest temperature recorded in 38 years
o Himalayan glaciers diminishing
 Increase demand due to developing country with an increasing population
 Neighboring countries e.g. China  building dams in Himalayan Mountains
negative impact because restricting water flow from rivers into Bangladesh
o Farakka dam on Ganges in India, 17km from border
o Indian barrage construction  lower water level of Teesta river
o Surface water of ponds & canals disappeared
 147 billion cubic meters required, only 90 available
 50-60% of irrigation water lost: improper technical management
 Reduction of biodiversity due to:
o Deforestation for firewood and financial gain
 55% cover in 1849, now under 17%
o Agriculture and mono-cropping of rice
 Reduction of crop land (over 50% land use is for agriculture)
 Insufficient water management and treatment facilities
o Lack of energy, money, awareness
 Diesel: main power for irrigation, but price is increasing
 Impact on humans:
o Increased labor migration
o Decreased hygiene
o Food insecurity
SOLUTIONS:
 For food insecurity:
o Planting direct seeded rice, then rabi crops to “take advantage of residual
moisture soon after rice harvest”
o Cassava and yams: drought resistant & do not need a lot of water
o Adapting to eating different foods e.g. leaves and grasses
o Introducing less water-intensive crops e.g. maize and wheat and high
economic value crops e.g. chickpeas and mangoes
 Community education
Linda Rousseva
08.12.2013
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o Reversing climate change impacts
o Family planning
Helping small-scale farmers (90% of farming in the area is small-scale) to cope with
rising diesel prices for irrigation
Training in proper irrigation and soil management to increase efficiency of use
Piping domestic water to households, using the community for manual labor
References:
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"The Causes and Distribution of Deserts." Revision World. N.p., n.d. Web. 03 Dec. 2013.
Coping with Water Scarcity. Publication. Rome: FAO, 2012. Print.
Garrington, Sally. Water Supply Conflict: Las Vegas and the Great Basin Aquifer. Rep.
Geofile Online, Sept. 2011. Web. 8 Dec. 2013.
"Introduction to Wastewater Treatment Processes." Water Home. The World Bank,
2013. Web. 30 Nov. 2013.
"Map Details Global Water Stress." BBC News. BBC, 21 Aug. 2006. Web. 02 Dec. 2013.
Mbugua, Alice. Water Scarcity in Northern Bangladesh. Rep. Surrey: Voluntary Services
Overseas, 2011. Water Scarcity in Northern Bangladesh. Web. 8 Dec. 2013.
Pfly. Ganges-Brahmaputra-Meghna Basins. Digital image. Wikimedia Commons, 30 Apr.
2011. Web. 8 Dec. 2013.
Rain Shadow Effect. Digital image. LIBGuides. University of Wisconsin, 12 Dec. 2010.
Web. 5 Dec. 2013.
Water Scarcity. Digital image. World Water Assessment Programme, Mar. 2012. Web. 2
Dec. 2013.