Transcript Water_Pollution

Surface & Groundwater
Pollution In Developing
Nations
Introduction
Surface & Groundwater
The Hydrologic Cycle
• Water Basics
– Sea water
– Fresh Water
97.2%
2.8%
• Polar ice & glaciers 2.15%
• Groundwater
0.62%
• Lakes and Rivers
0.01%
The Hydrologic Cycle
• The Three Fates of Precipitation
– Infiltration
• The movement of water into rocks or soil through
cracks and pore spaces
– Runoff
• Water that flows over the land
– Transpiration/Evapotranspiration
• the release of water vapor to the atmosphere by
plants
The Hydrologic Cycle
• Infiltration capacity of the soil is controlled
by:
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Intensity and duration of rainfall
Soil saturation
Soil texture
Slope of the land
Nature of the vegetative cover
Main Sources of Water
• Surface Water
– Lakes, rivers, reservoirs
• Ground Water
– In the Earth, flows through fractures and pores
Surface Water – Stream
Valleys
• Flood Plains
– Periodic floods deposit rich soils
• Agricultural production on floods plains is followed
by urbanization
– Natural levees
• Forms as floods deposit coarse detritus near the river
• Naturally constraint the river except in the larger
floods
Surface Water – Flooding
• Floods and flood control
– Floods are the most common geologic hazard
– Causes of floods
• Weather
• Human interference with the stream system
Surface Water – Flooding
• Floods and flood control
– Engineering efforts
• Artificial levees
• Flood-control dams
• Channelization
– Nonstructural approach through sound
floodplain management
What is Groundwater?
• Water found in the
pores and fractures of
soil and bedrock
• Largest reservoir of
fresh water
• Tends to be less
polluted than surface
water
What is Groundwater?
• An important erosional
agent
– Groundwater is often
mildly acidic
– Contains weak carbonic
acid
– Forms caverns at or just
below the zone of
saturation
– Karst topography on the
surface
Groundwater Terminology
Groundwater Movement &
Storage
• Factors
– Porosity
• Percentage of total volume of rock or sediment that
consists of pore spaces
– Determines how much groundwater can be stored
– Variations can be considerable over short distances
– Permeability
• The ability of a material to transmit a fluid
Groundwater Movement &
Storage
• Factors (continued)
– Specific retention
• The portion whish is retained as a film on particles,
rock surfaces, and pore spaces
– Specific yield
• The portion which will drain under gravity
– In general,
• Porosity = Specific retention + Specific yield
Groundwater Movement &
Storage
• Factors (continued)
– Aquifer - A zone of Earth material capable of
supplying groundwater at a useful rate from a
well
Groundwater Movement &
Storage
• Factors (continued)
– Aquitard - A zone of Earth material that holds
water but cannot transmit it fast enough to
pump from a well
Getting Groundwater Out of
the Ground
• Extraction Methods
– “Natural” Methods
• Springs, Hot Springs, & Geysers
Getting Groundwater Out of
the Ground
• Extraction Methods (continued)
– Man-made Methods
• Wells
Getting Groundwater Out of
the Ground
• Problems with groundwater removal
– Non-renewable resource
– Subsidence
– Contamination
Sources of Contamination
• Natural Sources
– Biologic activity / organisms
– Naturally occurring elements
• Human Caused
– Acid Rain
– Agricultural / Industrial Run-off
Sources of Contamination
• Natural Sources
– Bacteria and viruses
– Uranium, radium, arsenic, and fluoride
– Often naturally occurring in rock formations
Sources of Contamination
• Human Caused
– Acid Rain
• Acid rain is caused by:
– CO2 from cars and power plants
– NOx from cars
– SO2 from power plants
Sources of Contamination
• Human Caused
– Agricultural / Industrial Run-off
• Leakage from waste disposal, treatment, or storage
sites.
• Discharges from factories, industrial sites, or sewage
treatment facilities.
• Leaching from pesticides and fertilizers on yards or
fields.
Sources of Contamination
• Human Caused
– Agricultural / Industrial Run-off
• Accidental chemical spills.
• Leakage from underground storage tanks.
• Improper disposal of household wastes such as
cleaning fluids, paint, and motor oil.
Population and Water
Resources
Population & Water Resources
• Urban population
– The average size of the world's 100 largest
cities
– ~0.2 million in 1800
– ~0.7 million in 1900
– ~6.2 million in 2000.
Source: UNESCO
Population & Water Resources
Proportion of the population living in urban
settlements:
More developed regions:
70.0% in 1975
75.5% in 2000
78.5% in 2015
Less developed regions:
27.0% in 1975
40.5% in 2000
48.5% in 2015
Source: UNESCO
Urban water supply and
sanitation
• Proportion of households in major cities
connected to piped water:
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World: 94%
Africa: 43%
Asia: 77%
Europe: 92%
Latin America / Caribbean: 77%
North America: 100%
Oceania: 73%
Source: UNESCO
Urban water supply and
sanitation
• Proportion of households in major cities
connected to sewers:
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World: 86%
Africa: 18%
Asia: 45%
Europe: 92%
Latin America / Caribbean: 35%
North America: 96%
Oceania: 15%
Source: UNESCO
Urban water supply and
sanitation
• Urban child mortality
– In the urban areas of low-income countries, 1
child in 6 dies before the age of five.
– In areas poorly served with water and
sanitation, the child mortality rate is multiplied
by 10 or 20 compared to areas with adequate
water and sanitation services.
Source: UNESCO
Urban water supply and
sanitation
• Toilets and latrines
– Infectious diseases transmitted by human
excreta:
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cholera,
typhoid,
infectious hepatitis,
polio,
cryptosporidiosis,
and ascariasis
Source: Worldwaterday.org
Urban water supply and
sanitation
• Toilets and latrines
– Uganda Ministry of Health study
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1995 – One toilet for every 328 students
2001 – One toilet for every 700 students
Attributed to increased enrollment in schools
33% of 8000 schools had separate latrines for girls
Source: Worldwaterday.org
Urban water supply and
sanitation
• Toilets and latrines
– Prevention / control
• Low population density
areas
– On-site systems such as
ventilated improved pit (VIP)
latrines, double vault
composting latrines, pourflush toilets, and septic tanks.
Desludging latrine pits in slum areas is not
easy. This specially designed 'Vacutug' is
doing good work in Kibera, Nairobi
(Picture: IRC/Madeleen Wegelin )
Source: Worldwaterday.org
Urban water supply and
sanitation
• Toilets and latrines
– Prevention / control
• High population density areas
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Off-site sewage treatment plants
Sewer systems
Requires adequate infrastructure
Low-tech waste stabilization ponds also a low-cost option
Source: Worldwaterday.org
Water and health
• Diarrheal diseases
– 6,000 deaths per day
• mostly among children under
five.
– How to prevent?
• WASH YOUR HANDS!
Some children wash their hands in a
bucket, demonstrating safe hygiene.
Source UNICEF [email protected]
Source: UNESCO
Water and health
• Malaria
– Over 1 million people die from malaria every
year.
– About 90 percent of the annual global rate of
deaths from malaria occur in Africa south of the
Sahara.
– How to prevent?
• Sleep under mosquito nets
Source: UNESCO
Water and health
• Schistosomiasis (worms)
– More than 200 million people worldwide are
infected by schistosomiasis.
– 88 million children under fifteen years are
infected each year with schistosomes.
– 80 percent of transmission takes place in Africa
south of the Sahara.
Source: UNESCO
Water pollutants from industry
• Some 300-500 million tons of heavy metals,
solvents, toxic sludge, and other wastes
accumulate each year from industry.
• In developing countries, 70% of industrial
wastes are dumped untreated into waters
where they pollute the usable water supply.
Source: UNESCO
Pressures on freshwater
ecosystems
• Main threats to ecosystems from human
activities
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Population and consumption growth.
Infrastructure development
Land conversion
Overharvesting and overexploitation
Release of pollutants
Introduction of exotic species
Source: UNESCO
Pressures on freshwater
ecosystems
• River pollution
– Every day, 2 million tons of human waste are
disposed of in water courses.
– 40% of water bodies assessed in 1998 in the
United States were not deemed fit for World
distribution of hydropower recreational use due
to nutrient, metal and agricultural pollution.
Source: UNESCO
Pressures on freshwater
ecosystems
• River pollution
– 5 out of 55 rivers in Europe are considered
pristine
– In Asia, all rivers running through cities are
badly polluted.
Source: UNESCO
Pressures on freshwater
ecosystems
• Wetlands loss:
– 50% of the world's wetlands have been lost
since 1900.
– More than 80% of the wetlands along the
Danube River have been destroyed since the
start of the 20th century.
– The Mesopotamian Marshlands in the Tigris
and Euphrates river basins were devastated by
damming and river channelization.
Source: UNESCO
Pressures on freshwater
ecosystems
• Biodiversity loss:
– Between 34 and 80 fish species have become
extinct since the late 19th century, 6 since 1970.
– At a global level, around 24% of mammals and
12% of birds are classified as threatened.
– In the United States, 120 of 822 freshwater fish
species are considered threatened, representing
15% of total fish species.
Source: UNESCO
Sharing Water Resources
• Conflict and cooperation
– There have been 1,831 interactions (both
conflictual and cooperative) over the last fifty
years.
– The concept of 'virtual water' has been
developed which allows nations and states to
share the products and benefits.
Source: UNESCO
Case Studies
1. Gujarat, India
2. Bangkok, Thailand
3. Aral Sea
Gujarat, India
• Physiography
– Salt deserts in
Kachchh
– Wet & fertile in
SE
• 2/3 of population
engaged in
agriculture
Gujarat, India
• Water Sources:
– Three perennial rivers flowing through South
Gujarat
– One major non-perennial river flowing in the
central NW portion of the state
– Rainfall is erratic
Gujarat, India
• Area is susceptible to drought
• Exacerbated by:
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rocky terrain,
desert region,
a 1600 Km long coastline
and deteriorating ground water quality.
Gujarat, India
• The problem: Over extraction of
groundwater
• The Result? Up to 40 meters drop in water
table
– Drops ~3 – 5 meters/year
Gujarat, India
• The problem: Over extraction of
groundwater
– ~14,000 villages out of 18,500 villages suffer
from severe water scarcity every year.
– Poor can only afford “dug” wells – 10 m depth
max
– 15 Districts ( more than 2000 villages) are
affected by fluoride, and 16 districts are
affected by salinity.
Gujarat, India
• Gujarat Infrastructure Development Board
– Plans on utilizing groundwater as main water
source
– Diversion of water in the South and Central
regions to the North
Gujarat, India
• Gujarat Infrastructure Development Board
– Construction of
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check dams,
percolation tanks,
village tanks,
river beds etc. for the recharge of ground water.
– Recycling and re-utilization of sewerage water
in big cities and towns
Gujarat, India
• Will this work?
• What about groundwater contamination?
Bangkok, Thailand
• Physiography:
– Hilly to mountainous
– Low-lying delta
region
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• Water sources
– Lots of rain
– Lots of rivers
Bangkok, Thailand
• The problem: Over extraction of
groundwater
• The result? Land subsidence in Bangkok
– Up to 10 cm/year (now 1 – 2 cm /year)
– Due to government’s lack of planning
Bangkok, Thailand
• Problems due to land subsidence:
– changes in elevation and slope of streams,
canals, and drains
– damage to bridges, road, railroad, storm drains,
sanitary sewers, canals, and levees
– damage to private and public buildings
Bangkok, Thailand
• Problems due to land subsidence:
– in some southern coastal areas, subsidence has
resulted in tides moving into low-lying areas
that were previously above high-tide levels;
– cost of pumping storm water and sewage out to
Chao Phraya river and Gulf of Thailand.
Bangkok, Thailand
• Government solution:
– Expansion of water works service to cover the
area
– A pricing system to discourage excess groundwater use
– Groundwater recharging
– Public information on water saving.
Bangkok, Thailand
• Will this work?
Aral Sea Basin
• Once a large Pleistocene salt
water lake (4th largest)
• Located between Kazakhstan
to the north and Uzbekistan
in the south
• Desert-continental climate
– Extreme temperatures, cold
winters, hot summers, and
sparse rainfall
• Precipitation rate =
evaporation rate
Aral Sea Basin
• Natural factors affecting the lake
– Inflow from rivers (4/5th of total inflow
– Increasing evaporation rates / decreasing
rainfall
Aral Sea Basin
• The problem:
– Diversion of water for agricultural irrigation
• The result?
– Increased salinity
– Decreased volume
Shrinkage of the Aral Sea,
1960–99
Adapted from Philip Micklin, Western Michigan University
Aral Sea. Encyclopædia Britannica. Retrieved August 4, 2004, from Encyclopædia Britannica
Premium Service. <http://www.britannica.com/eb/article?eu=9293>
Development of ecological crisis in
the basin of the Aral Sea
Units of
measurement
1966
1976
1996
2000
Territory of "new" salty desert
appeared as a result of the sea
drying off.
sq. km.
No
130200
38000
42000
Physical mass of salt, dust and
wastes within salty desert
mln ton.
No
500
2300
3300
Territory of salt and dust
spread
thousand sq. km
No
100-150
250300
400450
Growth of withdrawal and fall
out of salts and dust
kg/hect
No
100-200
500700
7001100
Population in the zone of
ecological crisis
thousand people
No
500-600
30003500
35007000
Source: State of Environment of the Aral Sea Basin
Source: State of Environment of the Aral Sea Basin
Aral Sea Basin
• Impact on Climate
– Used to regulate cold winds from Siberia &
moderate summer heat
– Now short, dry summers and long, cold winters
– Frequent dust storms
Sources: State of Environment of the Aral Sea Basin ,
Britannica.com
Aral Sea Basin
• Impact on Soils
– Desertification
– Loss of topsoil
– Dust storms transport pesticide-laden soil to
Arctic regions
– Farming without irrigation impossible
Source: State of Environment of the Aral Sea Basin
Aral Sea Basin
• Impact on cryosphere
– Deposition of dust and mineral-rich
precipitation = glacial melting
– Glaciers lost
• 1081 in the Pamir-Altay area
• 71 glaciers in the Zaili Alatau area
Source: State of Environment of the Aral Sea Basin
Aral Sea Basin
• Impact on cryosphere
– Loss of fresh water supply
– Loss of main atmospheric moisture
condensators of the region.
Source: State of Environment of the Aral Sea Basin
Aral Sea Basin
• Impact on inhabitation sphere
– People moving elsewhere due to pollution, lack
of drinking water, and loss of soil
– Pollutants include:
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oil hydrocarbons,
phenols,
heavy metals and minerals,
and pesticides.
Source: State of Environment of the Aral Sea Basin
Aral Sea Basin
• Impact on inhabitation sphere
– destruction of fishery,
– the appearance of cancerogenic diseases,
– and changes in citogenetic indices
Source: State of Environment of the Aral Sea Basin
Aral Sea Population Density
Source:
State of
Environme
nt of the
Aral Sea
Basin
Aral Sea Basin
• Impact on biodiversity
– Historically:
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500 kinds of birds,
200 species of mammals
100 species of fishes,
thousands of insects and invertebrates.
Sources: State of Environment of the Aral Sea Basin ,
Britannica.com
Aral Sea Basin
• Impact on biodiversity
– Pre-1960: 70 kinds of
mammals and 319 types of
birds
– Today: 32 kinds of
mammals and 160 types of
birds remain
– Fishing industry destroyed
A former harbor in the city of
Aral, Kazakhstan
Sources: State of Environment of the Aral Sea Basin ,
Britannica.com, Wikipedia, the free encyclopedia
Aral Sea Basin
• Impact on the social and economic spheres
– Region has the highest infant mortality rate in
the former USSR
– High level of maternity death
– Increase in TB, infections and parasites, typhus,
hepatitis, paratyphoid
– Loss of jobs, etc.
Source: State of Environment of the Aral Sea Basin
Aral Sea Basin
• Other problems
– Part of the area was a Soviet WMD testing site
• Tularemia
• Bubonic plague
• Anthrax (live spores as of 1999)
Sources: Britannica.com
Aral Sea Basin
• What is being done?
– Governments have tried to institute waterconservation policies & encourage use of less
water intensive agriculture
– Region not stable, hard to implement
Sources: Britannica.com
Aral Sea Basin
• Possible Solutions to Problems
– Improving the quality of irrigation canals;
– Installing desalination plants;
– Charging farmers to use the water from the
rivers;
– Using different cotton species, which use less
water;
– Melting glaciers in Siberia, and moving the
water to refill the Aral.
– Using fewer chemicals on the cotton
Source: Wikipedia, the free encyclopedia
Aral Sea Basin
• In 1994 Aral Sea Basin Program (ASBP), with the
assistance of UNEP and the World Bank, was
launched.
• The main objectives of the ASBP are:
– stabilize the environment of the Aral Sea Basin;
– rehabilitate and disaster area around the sea;
– improve management of land and water resources in the
basin
– build capacity of institutions at all levels to plan and
implement these programs
Source: State of Environment of the Aral Sea Basin
Aral Sea Basin
• Will the Aral Sea be saved?
• Should it be saved?
Water Education
Water Education
• Educating the public is key to insuring good
water quality & supply
• Problem:
– Politics
– Literacy rates
– Prejudices
Source: UNESCO
Water Education
• Primary school
– Today, 79% of the world's children aged 6 to 11
are enrolled in primary school.
– 60% of these are girls.
– 4 out of 10 primary-age children in sub-Saharan
Africa do not attend school.
Source: UNESCO
Regional distribution of primary-age children not enrolled
1998-2000. Global total - 114 million in 2000.
[Figure source]: The Millennium Development Goals: Progress, Reversals and Challenges. UNDP, 2000.
Gross enrolment ratio at primary level
in 1997 (male/female)
Gross enrolment ratio at secondary
level in 1997 (male/female)
Gross enrolment ratio at tertiary level in
1997 (male/female)
[Figure source]: UNICEF, 2002. The State of the world's Children 2002.
Estimated illiteracy rate in 2000 (male
and female, age 15) in percentage.
[Figure source]: UNICEF, 2002. The State of the world's Children 2002.
Water Education
• Will it work?
~ End ~