Linda Rousseva08.12.2013

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 Rousseva08.12.2013

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 Rousseva08.12.2013

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 Rousseva08.12.2013

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 variabilityo Droughto 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 controlo Not dumping it in places where it cannot be re-used e.g. the seao Using it for agriculture i.e. irrigation because it is rich in plant nutrientso 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 solidso Reduces BOD (biological oxygen demand, i.e. how many

organisms are living in the water) by 20%

Linda Rousseva08.12.2013

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

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 (Nevada-California) 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% fullo 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 testso Mining minerals in the desertso Constructing and maintaining dams for water supplyo Electronic industries (clean, dry air)

Tourism e.g. Grand Canyon Climate change may be a cause, because:

o Rain-bearing winds track further northo Average temperature has increased over last 25 years

Linda Rousseva08.12.2013

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/yearo 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 rightso 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

Linda Rousseva08.12.2013

o Warm & humid: average temperature is 26˚C and average annual rainfall is 2540mm

External rivers 92% water in Bangladesho 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 scarcityo Change of Monsoon direction from heading North to heading Easto 19 drought periods 1960-1991o 1˚C rise in average May temperature 1985-1998o 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 Bangladesho 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 facilitieso Lack of energy, money, awareness

Diesel: main power for irrigation, but price is increasing Impact on humans:

o Increased labor migrationo Decreased hygieneo 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 watero Adapting to eating different foods e.g. leaves and grasses

Linda Rousseva08.12.2013

o Introducing less water-intensive crops e.g. maize and wheat and high economic value crops e.g. chickpeas and mangoes

Community educationo Reversing climate change impactso 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:

"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.