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Global Water Crisis: Depletion & Consequences

Explore the shrinking Lake Chad & Aral Sea, water scarcity in Lake Victoria, and the effects of dam construction. Learn about the alarming drop in water levels and the alarming growth in population around the world's water sources.

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Global Water Crisis: Depletion & Consequences

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  1. THEMATIC SLIDES

  2. WATER AND LAKES

  3. WATER AND LAKES • Lake Chad, Nigeria, Niger, Chad, Cameroon • Challawa Gorge Dam, Nigeria • Lake Nakuru, Kenya • Lake Victoria, Uganda • Lesotho Highlands Water • Project, Lesotho • Aral Sea, Kazakhstan • Lake Balkhash, Kazakhstan • Kara- Bogaz -Gol (KBG), Turkmenistan Estimated global water loss in irrigation Source: FAO

  4. WATER AND LAKES • Dead Sea, Jordan • Lake Hamoun, Iran • Mesopotamia Marshlands, Iraq • Three Gorges Dam, China • Atatürk Dam, Turkey • Gabcikova, Slovakia • Lake Chapala, Mexico • Everglades, United States Three Gorges Dam, October 24, 2003: Digital Globe

  5. WATER FACTS • Of total world water, 97.5% is salty water and only 2.5% is freshwater of which useable freshwater accounts for about 0.5% • Of the 0.5% useable freshwater, irrigation accounts for 70%, industry 20% and household 10% • Demand for and use of freshwater has tripled over the past half century,as world population has grown from 2.5 to 6.45 billion people • Experts predict that by 2025 global water needs will increase with 40% more required for cities and 20% for growing crops • The satellite photos show major freshwater depletion taking place on all continents, notably in the Dead Sea, the Aral Sea, Lake Chad, the Mesopotamian Marshlands, the Everglades and other water sources • According to UNESCO estimates, by 2030 global demands for fresh water will exceed the supply with potentially disastrous consequences Sources: Asian Development Bank; BBC; Earth Observatory; UNEP; UNESCO

  6. WATER FACTS • Water withdrawals are causing major rivers—such as the Colorado, the Nile, the Yellow Rivers—to run dry, lakes to vanish and groundwater tables and aquifers to drop almost everywhere • Over the next 20 years, average water supply per person is estimated to drop by a third, endangering human health, agriculture and the environment • Water volume in the Aral sea has dropped by about 80% since 1960s, due to extensive irrigation primarily for cotton production • Current water levels in Lake Victoria are below normal and the lowest level since September 1961 • In 2002, around 3.16 billion people (82%) in the Asia Pacific region had access to improved water supplies, up from 74% in 1990 • Water pollution is a serious threat to the world’s water supply Sources: Asian Development Bank; BBC; Earth Observatory; UNEP; UNESCO

  7. Shrinking Lake ChadNigeria, Niger, Chad, Cameroon Persistent drought has shrunk the lake to about a tenth of its former size • 1972: Larger lake surface area is visible in this image • 2001: Impact of drought displays a shrunken lake, comparatively much smaller surface area than in 1972 image

  8. Impact of Challawa Gorge Dam, Nigeria These images show the area before and after construction of the dam. • 1990: Image of the area before the completion of the dam in 1993 • 1999: Impact of flooding upstream from the dam; colour of the water in the flooded area indicates high sediments

  9. Land cover degradation around Lake Nakuru, Kenya These images show the land cover degradation in the lake’s catchment • 1973: The area that hosts the world’s largest concentration of flamingos • 2000: Excision of forest in the Eastern Mau Forest Reserve (white lines) will most likely lead to disappearance of upper catchment forest cover

  10. Water hyacinth in Lake VictoriaUganda These images show water hyacinth infestation and control of such invasive species • 1995: Image shows several water-hyacinth-choked bays (yellow arrows) • 2001: A visible reduction of Water Hyacinth, after its removal from Lake Victoria, contributes to human prosperity

  11. Population growth around Lake VictoriaUganda • The population growth around 100 km buffer zone of the Lake Victoria • Population growth around Lake Victoria, East Africa, is the highest in Africa

  12. Fastest growing rural population around Lake Victoria, Uganda

  13. Lake Victoria vs. Africa

  14. Title Height variation of Lake Victoria, Uganda Body text Lake Victoria Height Variations http://www.pecad.fas.usda.gov/cropexplorer/global_reservoir/gr_regional_chart.cfm?regionid=eafrica&region=&reservoir_name=Victoria

  15. Title Monitoring Lake Victoria, Uganda Body text Current water levels are below normal and the lowest level since September, 1961

  16. Changes due to dam construction in LesothoLesotho The Lesotho Highlands Water Project diverts water for South Africa’s urban and industrial use • 1989: Image of the area before the completion of the dam in 1995 • 2001: Katse dam created an enormous reservoir, the extent of which can clearly be seen in this image

  17. Death of a sea - Aral Sea, Kazakhstan Images show death of the world’s fourth largest inland sea • 1973: The surface of the sea once measured 66 100 km2 • 1987: 60% of the volume had been lost • 1999-2004: The sea is now quarter of the size it was 50 years ago

  18. Alarming drop in Lake Balkhash’s water levelKazakhstan • 1975-1979: Excessive use and waste of lake water are causes of the drop • 2001: Smaller neighbouring lakes appear to be drying up

  19. Kara-Bogaz-Gol – Lagoon of the Caspian seaTurkmenistan Caspian Sea is the largest inland body of water in the world • 1988: KBG is the large shallow lagoon of the Caspian sea • 2000: Caspian Sea levels are higher than 1978 levels and water flows freely into salty waters of KBG

  20. Dramatic changes in Dead Sea, Jordan Images show dramatic changes in the Dead sea over 30 years • 1973: The Sea level is dropping at the rate of 1m/year • 2002: Notice the expansion of salt works, and near-complete closing off of the southern part by dry land

  21. Changes in water levels on Lake HamounIran Changes in water levels on Lake Hamoun • 1976: The amount of water in the lake is relatively high • 1999-2001: The lake dried up and disappeared

  22. Demise of an ecosystem – Mesopotamian Marshlands, Iraq • 1973-2000: Most of the wetlands disappeared Upstream damming as well as drainage activities in the marshlands themselves have significantly reduced the quantity of water entering the marshes

  23. Restoration of the Mesopotamia Marshlands in Iraq • 2000: Water returns to the Mesopotamian Marshlands • 2004: Greening of some of the Marshlands in recent years

  24. Changes due to Three Gorges Dam construction, China Changes due to the construction of dam • 1987: Nature of the river and surrounding landscape before the dam • 2004: The enormous dam is clearly visible

  25. Changes due to Atatürk Dam, Turkey Development of Harran region is strikingly apparent in these images Right-hand corner of the 1999 image shows irrigated fields surrounding the town of Harran The dam provides power and irrigation water

  26. Damming around Gabcikova, Slovakia 1973-2000: Images show changes brought about by massive re-channeling of river water

  27. Country’s largest natural lake - Lake ChapalaMexico • 1983: Level of the lake has declined; noticeable decreases in wetlands • 2001: Alteration in the contours of the shoreline is clearly visible

  28. Urban encroachment in Florida’s EvergladesUnited States • 1973: Rapid urban expansion has converted farmlands to cityscapes • 2002: Existence of vast wetlands “Everglades” threatened by urban encroachment

  29. WATER AND LAKES • Lake Kivu, Congo/Rwanda • Lake Alaotra, Madagascar • Lake Al Wahda, Morocco • Lake Cahora Basa, Mozambique • Lake Chivero, Zimbabwe • Lake Djoudj, Senegal • Lake Ichkeul, Tunisia • Lake Manantali, Mali • Lake Sibaya, South Africa • Songor Lagoon, Ghana • Lake Tonga, Algeria

  30. LAKE FACTS • According to the WORLDLAKE database, there are 677 lakes in Africa • There are 15 natural lakes that cross the political boundaries of two or more countries in Africa • There are 60 transboundary river basins in Africa, covering over 63 per cent of the continent’s land area • Lake Chad’s surface area has shrunk by 95 per cent over the past 35 years • Uncontrolled damming, the withdrawal of water for irrigation, and climate variability are the major causes of drying up of Lake Tonga in Algeria • Population growth around Lake Victoria, the continent’s largest lake, is significantly higher than the rest of Africa • Some lakes in central Africa have become known as “killer lakes,” because of the catastrophic natural events that have occurred in their vicinity Sources: UNEP 2006

  31. Lake Kivu-one of Africa’s “killer lakes”Congo/Rwanda These images show dramatic changes before and after the eruption of Mt. Nyiragongo in 2002 • 2001: Before the January 2002 eruption • 2003: Shows the track of the lava flow

  32. Severe flooding around Lake AlaotraMadagascar These images show flooding over a wide area • Flooding destroys significant portion of crops • Intensive rice irrigation occurs at the western part of the lake (yellow arrows)

  33. Impact of Al Wahda reservoir in Morocco These images illustrate the change in land cover • 1987: The area before the construction of dams • 2001: The area after the construction of 110 large dams

  34. Cahora Basa – Mozambique’s largest dam on the Zambezi River These images show spectacular changes in the Zambezi riverine system • 1972: The Zambezi River a few years before the dam construction • 1999: This image shows part of the enormous dam and the lake

  35. Invasive water weeds in Lake Chivero, Zimbabwe These images show overall reduction in water weeds • 1989: Weeds show up as green strands along the edges of the lake • 2000: This image shows that water weeds remains a persistent problem

  36. Rejuvenation of the Djoudj Sanctuary in Senegal These images show the Djoudj Sanctuary before and after the construction of the Diama Dam • 1979: Shows the impact of drought on the Djoudj Sanctuary • 1999: Rejuvenation of the Sanctuary wetlands due to significant floods

  37. Ecological changes around Lake Ichkeul, Tunisia These images show the impact of damming • 1972: Shows the three feeder rivers supplying the lake before they were dammed • 2000: Shows the location of the dams (yellow arrows)

  38. Agricultural expansion around Lake Manantali, Mali These images show the expansion of irrigated agriculture • 1977: Shows the original meandering nature of the Bafing River • 1999: Shows the expanded irrigated land and increase in lake water quantity

  39. Lake Sibaya – wetland of international important in South Africa These images show increase in cultivation around the lake • 1991: Lakeshore is home to the only known species of a rare climbing orchid • 2001: The yellow arrows vividly show the increase of cultivation of marginal lands around the lake

  40. Reduction in the surface area of Songor Lagoon, Ghana These images show a conspicuous reduction in the surface area • 1990: Shows major lagoon system associated with Volta river estuary • 2000: This image shows water area dramatically reduced, exposing bare ground

  41. Changes in and around Lake TongaAlgeria These images show the changes brought about by damming of the feeder rivers • 1988: Lake Tonga before the damming of feeder rivers • 2000: Damming increased irrigation and drastically reduced the volume of water entering the lake

  42. WATER One Planet Many People: Atlas of Our Changing Environment Thank You! Free Downloads: www.na.unep.net Purchase: www.Earthprint.com

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