Vital Water


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  • Vital Water

    1. 1. Vital Water Alice Newton University of Algarve Joint Master in Water and Coastal Management University of Bergen 2005-2006
    2. 2. Bibliography <ul><li>Books : </li></ul><ul><ul><li>Philip Ball 1999: H 2 O A biography of Water ISBN 0 75381 092 1 </li></ul></ul><ul><ul><li>Peter H. Gleick 1993: Water in Crisis Oxford University Press </li></ul></ul><ul><ul><li>Open University course team 1997 : Seawater: its composition, properties and behaviour </li></ul></ul><ul><ul><li>Frank J. Millero 1996 : Chemical Oceanography, CRC Press </li></ul></ul>
    3. 3. Bibliography 2 <ul><li>Web </li></ul><ul><ul><li>United Nations Environment Program Vital Water Graphics </li></ul></ul><ul><ul><li>Global International Water Assessment </li></ul></ul><ul><ul><li>Intergovernemntal Panel on Climate Change </li></ul></ul>
    4. 4. Objectives <ul><li>Vital water is an introductory lecture that relates both to integrated river basin management or integrated coastal zone management </li></ul><ul><li>It also links up with many other modules in the course </li></ul>
    5. 5. Requirements <ul><li>No special skills are required for this lecture </li></ul><ul><li>A knowledge of basic inorganic and environmental chemistry is useful. </li></ul>
    6. 6. Programme <ul><li>The constituents of water </li></ul><ul><li>The water molecule </li></ul><ul><li>Properties of water </li></ul><ul><li>The origin of water </li></ul><ul><li>The hydrological cycle </li></ul><ul><li>Composition of natural waters </li></ul><ul><li>Ice and glaciation </li></ul><ul><li>Water and life </li></ul><ul><li>Water the destroyer </li></ul><ul><li>Water and society, resources, uses and abuses </li></ul>
    7. 7. Learning outcomes <ul><li>After completing this module you should know: that although water is a very common substance on Earth, it has strange properties and is a scarce resource </li></ul><ul><li>After completing this module you should be able to: Explain why water is so special and what some consequences are for water and coastal management </li></ul>
    8. 8. Other skills <ul><li>Consult scientific literature and websites </li></ul>
    9. 9. The Constituents of Water… a little chemistry <ul><li>Hydrogen (H ) </li></ul><ul><li>Oxygen (O) </li></ul><ul><li>H 2 O is the basic unit of water </li></ul><ul><li>Ratio 2:1 is a consequence of the atomic structure </li></ul>
    10. 10. Hydrogen (H) <ul><li>About ¾ of the mass of the Universe is Hydrogen! </li></ul><ul><li>H atom has 1 proton </li></ul><ul><li>H usually has no neutrons, so the atomic mass is 1 </li></ul><ul><li>0.000015 % of H has 1 neutron, so atomic mass is 2 (1 proton + 1 neutron) </li></ul><ul><ul><li>This isotope (different number of neutrons) is called “heavy” water, Deuterium, or Hydrogen-2 </li></ul></ul>
    11. 11. Oxygen (O) <ul><li>O atom has 8 protons </li></ul><ul><li>Mass of O is about 16 x mass of H (different isotopes and neutons) </li></ul><ul><li>O can have 7, 8 , 9 or 10 neutrons </li></ul><ul><li>O is the third most abundant element in the Universe </li></ul><ul><li>(the second most abundant element in the Universe is Helium, relatively unreactive) </li></ul>
    12. 12. The Origin of H and O… a little cosmo-chemistry <ul><li>Current scientific theory </li></ul><ul><li>Protons (H + ) formed a millionth of a second after Big Bang, T~ a trillion degrees </li></ul><ul><li>Nucleosynthesis started one hundredth of a second later (protons+neutrons), T~ three billion degrees </li></ul><ul><li>Hydrogen atoms form, T~ 4000 ° C </li></ul>
    13. 13. The Origin of H, O and Water <ul><li>Gravity leads to formation of Galaxies and Stars Hans Bethe 1939 </li></ul><ul><li>Elements (C-N- O) formed in stars by fusion </li></ul><ul><li>Mainly generates 15 O but also 16 O 17 O Burbridge,Burbridge, Fowler and Hoyle 1957 </li></ul><ul><li>Water formed by reaction of H and O </li></ul>
    14. 14. From “Element” to compound <ul><li>Water classically was thought of as an Element </li></ul><ul><li>Lavoisiers’ experiments 1784 prove that water is formed by burning Hydrogen in the presence of oxygen. Hydrogen means “water former” </li></ul><ul><li>Nicholson and Carlisle split water by electrolysis to form hydrogen and oxygen </li></ul><ul><li>Berzelius recognized the fixed ratios H=2, O=1 </li></ul>
    15. 15. Water as a Liquid
    16. 16. Liquid water <ul><li>At present most of the water on Earth is in the liquid phase </li></ul><ul><li>Most liquid water (~97%) is in seawater </li></ul><ul><li>Water is the main component (~96%) of seawater </li></ul>
    17. 17. The Water Molecule <ul><li>Hydrogen (H) and Oxygen (O) </li></ul><ul><li>H 2 O is the basic unit of water </li></ul><ul><li>Ratio 2:1 </li></ul><ul><li>Consequence of atomic and molecular structure </li></ul>
    18. 18. Molecular Structure of Water <ul><li>Hydrogen atoms have a partial positive charge. </li></ul><ul><li>Oxygen has 2 unbonded pairs of electrons with partial negative charges. </li></ul><ul><li>Tetrahedral, distorted by charges to minimize repulsion </li></ul><ul><li>Molecular structure is &quot;bent&quot; to yield a 104.5° angle between the hydrogen atoms instead of 109.5° for a regular tetrahedron . </li></ul>
    19. 19. Hydrogen bonds <ul><li>A partly positive hydrogen atom of one water molecule attracts the partly negative unbonded electron pair in the oxygen atom, forming a hydrogen bond. </li></ul>
    20. 20. Hydrogen bonds <ul><li>The oxygen atom of a water molecule is the hydrogen bond acceptor for two hydrogen atoms . </li></ul><ul><li>Each O-H group serves as a hydrogen bond donor. </li></ul>
    21. 21. 4 Hydrogen bonds <ul><li>Leads to the formation of 4 hydrogen bonds by water </li></ul><ul><li>The tetrahedral structure of the water hydrogen bonds is a consequence of the sp3 hybridization of the oxygen's electrons. </li></ul><ul><li>The two hydrogen bonds between the oxygen and the hydrogen atoms on another water molecule utilize the two partly-negative pairs of unbonded electrons on oxygen. </li></ul>
    22. 22. Structure of liquid water <ul><li>The hydrogen bonding pattern of water is more irregular than that of ice. </li></ul><ul><li>The absolute structure of liquid water has not been determined . </li></ul><ul><li>Many theories e.g. Frank and Wen flickering cluster model : as a liquid, water has partly crystalline “clusters” but some “loose molecules” </li></ul>
    23. 23. Properties of Water The Strange Liquid
    24. 24. Density anomaly <ul><li>Most substances are denser in the solid than in the liquid phase </li></ul><ul><li>The structure of ice at 0 o C is less dense than that of liquid water at 0 o C because ice has a more rigid lattice. </li></ul><ul><li>Density maximum at 4 o C </li></ul><ul><li>Ice forms at surface and floats </li></ul><ul><li>Enormous implications for climate </li></ul>
    25. 25. High Specific Heat Capacity <ul><li>Very high energy required to change the temperature of water </li></ul><ul><li>Water is slow to heat and slow to cool </li></ul><ul><li>Warm ocean currents can therefore transport huge amounts of heat </li></ul><ul><li>Gulf Stream transports more heat daily than would be produced by burning global quantity of coal mined annually </li></ul>
    26. 26. Latent Heat Capacity <ul><li>Energy to change phase without changing temperature </li></ul><ul><li>When water is heated to 100ºC, is doesn’t all instantly evaporate to steam. A lot of heat has to be supplied to transform all the liquid into vapour. </li></ul><ul><li>When ice is reaches 0ºC, is doesn’t all instantly melt. A lot more heat must be applied to transform all the ice into liquid water </li></ul>
    27. 27. Specific Heat and Latent Heat Heat Energy Supplied 100 ºC 0 ºC T ºC Boiling Point Freezing Point Specific Heat of Water Specific Heat of Ice Latent Heat of Water Latent Heat of Ice
    28. 28. Phase transitions solid-liquid-gas <ul><li>Boundaries of phases are controlled by temperature and pressure </li></ul><ul><li>Phase diagram plots phases on a graph of temperature and pressure </li></ul>T P
    29. 29. Phase diagram of water
    30. 30. Triple Point <ul><li>Solid, Liquid and Gas phases can co-exist </li></ul><ul><li>Below Triple Point , solid sublimes to gas </li></ul><ul><li>Gas and Solid extend throughout T and P </li></ul><ul><li>Liquid is a “contigent” state, not always necessary </li></ul>
    31. 31. Critical Point <ul><li>Boundary between Liquid and Solid stops at Critical Point </li></ul><ul><li>Supercritical region: gas and liquid behave in same way </li></ul><ul><li>Gas and Liquid are both Fluids phases </li></ul>
    32. 32. More anomalous properties <ul><li>Excellent solvent , especially of ionic compounds </li></ul><ul><li>Highly reactive and therefore corrosive </li></ul><ul><li>Viscosity increases with pressure </li></ul><ul><li>High boiling point and freezing point </li></ul><ul><li>Low dissociation, but can act as an Acid or Alkali and is an electrolyte </li></ul>
    33. 33. Water as Ice
    34. 34. Molecular structure of ice <ul><li>Water molecules in ice form an open hexagonal lattice in which every water molecule is hydrogen bonded to four others. </li></ul><ul><li>The geometric regularity of these hydrogen bonds contributes to the strength of the ice crystal. </li></ul><ul><li>All hydrogen bonds are satisfied in ice. </li></ul>Structure of Ice I “ normal” ice
    35. 35. “ Normal” ice <ul><li>Ice I has hexagonal symmetry that we associate with snowflakes </li></ul><ul><li>Dendritic ( branching ) growth from a “seed” particle </li></ul>
    36. 36. Many types of ice <ul><li>Under pressure, Ice I can change to other forms e.g. ice II and ice III. </li></ul><ul><li>1998 Ice XII was discovered! </li></ul><ul><li>Some forms are very unstable e.g. ice IV and ice XII </li></ul><ul><li>I-V the hexagonal lattice is buckled </li></ul><ul><li>VI-XII several interlocking lattices </li></ul>
    37. 37. “ Weird” ice <ul><li>At ~ 3500 atm, Ice I can change to other forms e.g. ice II and ice III. </li></ul><ul><li>Ice VI will remain solid up to 80ºC, but melts at pressures less than 6500 atm ! </li></ul><ul><li>Ice VII is formed at 22000 atm, is twice as dense as ice I and melts at 100 ºC ! </li></ul><ul><li>Ice IX cannot exist at temperatures above -100 ºC ! </li></ul>
    38. 38. Amorphous, glassy ice <ul><li>Low density amophous ice forms by rapid freezing to -140 ºC </li></ul><ul><li>There is no “time” to form the lattice </li></ul><ul><li>Can only exist between -140 ºC and -120 ºC </li></ul><ul><li>Behaves like very viscous liquid </li></ul><ul><li>High density amorphous ice is formed from ice I at 10 000 atm and -196 ºC </li></ul>
    39. 39. Supercooled water <ul><li>Liquid water can also be supercooled </li></ul><ul><li>High altitude, low temperatures and pressures e.g. cirrus clouds ~38 ºC </li></ul><ul><li>Solutes also decrease the freezing point, e.g. seawater freezes at – 1.9 ºC </li></ul>
    40. 40. Where did the water on Earth come from?
    41. 41. Water in the Universe <ul><li>“ Excited” molecules of water radiate MASERS (Microwave Amplified Stimulated Emission of Radiation) </li></ul><ul><li>Water is </li></ul><ul><li>common in </li></ul><ul><li>the Universe </li></ul><ul><li>e.g. Orion’s </li></ul><ul><li>Horse Head </li></ul><ul><li>Nebula </li></ul><ul><li>Townes 1969 </li></ul>
    42. 42. Solar Systems <ul><li>Material orbiting stars can form a planetary solar system (such as ours) </li></ul><ul><li>Our solar system consists of </li></ul><ul><ul><li>Inner “rock” planets e.g. Earth and Mars </li></ul></ul><ul><ul><li>Outer “gas” planets e.g. Jupiter and Saturn </li></ul></ul><ul><ul><li>Planetesimals such as asteroids, meteorites and comets that maybe rich in water, CO 2 and NH 3 </li></ul></ul>
    43. 43. Our Solar System
    44. 44. Water in our Solar System <ul><li>Carbonaceous Chondrites (type of meteorite) contain 20% water as ice or in the structure of consitutent minerals </li></ul><ul><li>Common meterorites (Chondrites) contain 0.1% water </li></ul><ul><li>Comets contain huge amounts of water, typically one thousand trillion kgs! </li></ul>
    45. 45. e.g. Halley’s Comet <ul><li>Size 8km x 16km </li></ul><ul><li>Mass 100 trillion Kg </li></ul><ul><li>Mostly ice </li></ul>
    46. 46. Origins of Water on Planet Earth <ul><li>Collisions with Planetesimals such as asteroids, meteorites and comets brought water, CO 2 and NH 3 to the Earth </li></ul>
    47. 47. Formation of Lithosphere <ul><li>As Earth cooled, a rocky surface, the lithosphere, formed on the molten magma </li></ul>
    48. 48. Formation of early Atmosphere <ul><li>Cooling magma released volatiles by degassing to form early atmosphere </li></ul><ul><li>Early atmosphere was mainly CO 2 , N 2 and water vapour </li></ul>
    49. 49. Formation of Hydrosphere <ul><li>Between 4.4 and 4.0 billion years ago </li></ul><ul><li>Temperature low enough for condensation of water </li></ul><ul><li>Formation of clouds and rain </li></ul><ul><li>Formation of oceans </li></ul>
    50. 50. The Blue Planet
    51. 51. Water controls our Planet <ul><li>Geological change : erosion by rivers, glaciers and coastal erosion </li></ul><ul><li>Short term climate : El Niño, North Atlantic Oscillation </li></ul><ul><li>Climate change : Ice-ages </li></ul>El Niño
    52. 52. El Niño mechanism
    53. 53. Some facts and figures… <ul><li>Planet Water would be more appropriate as a name than planet Earth! </li></ul><ul><li>More than 2/3 of planet surface is water </li></ul><ul><li>More than 1/20 of planet surface is ice </li></ul><ul><li>Only tiny proportion, 1/10000, is freshwater </li></ul>
    54. 55. The Hydrological Cycle
    55. 56. Hydrological cycle <ul><li>Very dynamic cycling, main mechanisms are evaporation and condensation / precipitation </li></ul><ul><li>Balance between water in 3 states : solid, liquid, gas; ice, water and vapour </li></ul><ul><li>Hydrological cycle regulates and controls many other biogeochemical cycles </li></ul>
    56. 57. Water in the Sky… Clouds <ul><li>Volume equal to all the oceans passes through atmosphere ~3100 years </li></ul><ul><li>Atmosphere only contains about 0.001% of total water at any one time as clouds </li></ul><ul><li>Represents only 0.035% of all freshwater </li></ul><ul><li>Equivalent to about 2.5 cm of rain over all surface of globe </li></ul>
    57. 58. Formation of Clouds <ul><li>Process of condensation </li></ul><ul><li>Condensation nuclei </li></ul><ul><li>Airborne particles e.g. </li></ul><ul><ul><li>dust, </li></ul></ul><ul><ul><li>soot, </li></ul></ul><ul><ul><li>DMS </li></ul></ul>
    58. 59. Dimethyl Sulphide (DMS) <ul><li>Produced by phytoplankton </li></ul><ul><li>In atmosphere forms sulphate </li></ul><ul><li>Coalesces with sodium and magnesium ions from sea-salt </li></ul><ul><li>Forms crystalline particles that are condensation nuclei </li></ul>
    59. 60. Clouds <ul><li>Cumulus </li></ul><ul><li>Stratus </li></ul><ul><li>Alto-cumulus </li></ul><ul><li>Alto-stratus </li></ul><ul><li>Cirrus </li></ul><ul><li>Cumulo-nimbus </li></ul>
    60. 61. Cumulus <ul><li>low altitude </li></ul><ul><li>formed by convection of air </li></ul><ul><li>“ warm clouds“ mostly above 0ºC </li></ul><ul><li>fluffy and billowing </li></ul>Image ID: wea00079, Historic NWS Collection Photo Date: September 1980 Photographer: Ralph F. Kresge #1126
    61. 62. Stratus <ul><li>low altitude, </li></ul><ul><li>formed by convection of air meeting a stable layer </li></ul><ul><li>mostly above 0ºC </li></ul><ul><li>static </li></ul><ul><li>typical of overcast sky </li></ul>Image ID: wea02051, Historic NWS Collection Location: Oahu, Hawaii Photo Date: March, 1976 Photographer: Ralph F. Kresge
    62. 63. Alto-cumulus <ul><li>At higher altitudes </li></ul><ul><li>Formed at a lower temperature (0 to -39ºC) </li></ul><ul><li>Also Alto-stratus </li></ul>Image ID: wea00039, Historic NWS Collection Photographer: Ralph F. Kresge #1201
    63. 64. Cirrus <ul><li>high altitude </li></ul><ul><li>temperature below -39ºC </li></ul><ul><li>feathery </li></ul>Image ID: wea00062, Historic NWS Collection Location: Looking SSW at Rossmoor, Maryland Photo Date: 10:45 A.M., January 29, 1976 Photographer: Ralph F. Kresge
    64. 65. Alto-stratus <ul><li>At higher altitudes </li></ul><ul><li>formed at a lower temperature (0 to -39ºC) </li></ul>
    65. 66. Cumulo-nimbus <ul><li>cumulus topped by cirrus </li></ul><ul><li>storm cloud </li></ul>Image ID: wea00094, Historic NWS Collection Location: Mauna Kea, Hawaii Photo Date: February 1976 Photographer: Ralph F. Kresge #0221
    66. 68. Water Vapour and Global Change <ul><li>Water vapour is a greenhouse gas </li></ul><ul><li>Global warning may cause positive feedback : warming puts more water-vapour into atmosphere which causes further warming </li></ul><ul><li>Alternately more water-vapour into atmosphere may cause more, violent precipitation </li></ul><ul><li>Also consider albedo effect versus greenhouse effect </li></ul>
    67. 69. Evaporation and Transpiration <ul><li>~ 875 cubic km of water evaporate from the oceans every day </li></ul><ul><li>Equivalent to about 1m of the oceans annually </li></ul><ul><li>~ 160 cubic km of water evaporate from land and plants ( transpiration ) every day </li></ul>
    68. 71. Residence times <ul><li>Biospheric water </li></ul><ul><li>Atmospheric water </li></ul><ul><li>River channels </li></ul><ul><li>Swamps </li></ul><ul><li>Lakes and reservoirs </li></ul><ul><li>Soil moisture </li></ul><ul><li>Ice caps and glaciers </li></ul><ul><li>Ocean and seas </li></ul><ul><li>Groundwater </li></ul><ul><li>1 week </li></ul><ul><li>1.5 weeks </li></ul><ul><li>2 weeks </li></ul><ul><li>1-10 years </li></ul><ul><li>10 years </li></ul><ul><li>2 weeks-1 year </li></ul><ul><li>1000-100 000 years </li></ul><ul><li>4000 years </li></ul><ul><li>2 weeks-10 000 years </li></ul>
    69. 72. Runoff <ul><li>Precipitation on land - Evaporation on land = Runoff </li></ul><ul><li>~100 cubic km per day </li></ul><ul><li>Deserts: precipitation = evaporation </li></ul><ul><li>Amazon: </li></ul><ul><ul><li>precipitation >> evaporation </li></ul></ul><ul><ul><li>1/5 of freshwater input into oceans </li></ul></ul>
    70. 74. Oceans and Seas are all interconnected basins <ul><li>Atlantic </li></ul><ul><li>Pacific </li></ul><ul><li>Indian </li></ul><ul><li>Southern (Antarctic) </li></ul><ul><li>2/3 in South Hemisphere </li></ul><ul><li>Mediterranean Sea </li></ul><ul><li>Black Sea </li></ul><ul><li>North Sea </li></ul><ul><li>Red Sea </li></ul><ul><li>Arabian Sea </li></ul><ul><li>East and South China Seas </li></ul><ul><li>Arctic </li></ul>
    71. 75. Oceans … a little oceanography <ul><li>½ of the globe is 3 000-6 000m deep! </li></ul><ul><li>Ocean trenches reach 11 000m, mountains only 8000m </li></ul><ul><li>Mid-ocean ridges are the greatest mountain chains </li></ul>
    72. 76. Topography of Ocean Basins
    73. 77. Surface Currents <ul><li>wind </li></ul><ul><li>rotation (gyres) </li></ul><ul><li>N. Equatorial </li></ul><ul><li>S. Equatorial </li></ul><ul><li>West wind drift </li></ul><ul><li>Norway </li></ul><ul><li>North Atlantic </li></ul><ul><li>Canary </li></ul><ul><li>Brazil </li></ul><ul><li>Agulhas </li></ul><ul><li>Alaska </li></ul><ul><li>Oyashio </li></ul><ul><li>Kuroshio </li></ul><ul><li>Peru </li></ul>
    74. 78. Global Ocean Surface Currents
    75. 79. Deep Circulation, Global Conveyor <ul><li>thermohaline </li></ul><ul><li>Density driven </li></ul><ul><li>(T and S) </li></ul>
    76. 80. Tidal currents <ul><li>Up to 14m! </li></ul><ul><li>Gravitational pull (moon + sun) </li></ul><ul><li>24 h and 50 min cycle </li></ul><ul><li>Semi diurnal (High-Low-High-Low) </li></ul><ul><li>Lunar cycle (Spring-Neap-Spring-Neap) </li></ul>
    77. 84. River basins
    78. 86. Nile <ul><ul><li>Length: 6650 km </li></ul></ul><ul><ul><li>Catchment: ~ 3 million km 2 </li></ul></ul>
    79. 87. Amazon <ul><li>Length: 6450 km </li></ul><ul><li>Catchment: </li></ul><ul><li>~ 7 million km 2 </li></ul>
    80. 88. Volume of water transported <ul><li>Different climatic regions ( e.g. Nile and Amazon) </li></ul><ul><li>Dams </li></ul><ul><ul><li>Aswan: Lake Nasser 500km, +900 000 acres of arable land, ¼ of Egypt’s power </li></ul></ul><ul><ul><li>Itaipu </li></ul></ul><ul><ul><li>Three gorges estimate 18200 megawatts, reservoir ~660 km long </li></ul></ul>
    81. 89. Aswan Dam Lake Nasser
    82. 92. River basins <ul><li>Different geomorphology </li></ul><ul><li>Different size of flood plains </li></ul><ul><li>Erosion of rocks </li></ul><ul><li>Sediment transport </li></ul><ul><li>Dams </li></ul>
    83. 94. Groundwater <ul><li>Some rain permeates through ground ( aquifer ) until it reaches impermeable bedrock or clay. </li></ul><ul><li>Upper limit is water table </li></ul>
    84. 95. Groundwater quality <ul><li>Depends on rocks of aquifer </li></ul><ul><ul><li>Hard water: chalk and limestone </li></ul></ul><ul><ul><li>Soft water: slate and granite </li></ul></ul><ul><li>Mineral water: high concentration of dissolved minerals. Maybe volcanically heated, thermal. </li></ul><ul><li>Maybe contaminated by pesticides, fertilizers from agriculture or leachates from landfills </li></ul>
    85. 96. Characterization of Water by Mineral Composition … a little hydrochemistry
    86. 99. Ca 2+ <ul><li>Rain is acidic (~pH 5.5) </li></ul><ul><li>Dissolves carboniferous rocks Ca CO 3 </li></ul><ul><li>Temperature is important ( solubility decreases with increasing temperature) </li></ul><ul><li>K= [Ca 2+ ] [CO 3 2- ] = 10 -8,3 </li></ul><ul><li> (1:1) </li></ul><ul><li>P CO2 in soil < a P CO2 in the atmos ( P CO2 in soil ≈ 3 x 10 -4 atm.) </li></ul><ul><li>K= [Ca 2+ ] [HCO 3 - ] 2 = 10 -5,8 P CO2 </li></ul><ul><li> (1:2) </li></ul>
    87. 100. Bicarbonate HCO 3 - <ul><li>H 2 CO 3 Equilibrium </li></ul><ul><li>Controlled by pH </li></ul><ul><li>Normally HCO 3 - is dominant specie </li></ul><ul><li>Determine alkalinity of water </li></ul>
    88. 101. How do we represent the composition of water? <ul><li>Bar charts or Collins diagram </li></ul><ul><li>Pie charts </li></ul><ul><li>Kite or stiff diagrams </li></ul><ul><li>Radial diagrams </li></ul><ul><li>Triangular or Piper diagrams </li></ul><ul><li>Semi-logarithmic or Schoeller diagrams </li></ul>
    89. 117. Exploitation of aquifers <ul><li>Over exploitation may cause land subsidence e.g. London and Mexico </li></ul><ul><li>In coastal regions, seawater intrusion </li></ul>
    90. 118. Ice… the cryosphere
    91. 119. Ice Ages <ul><li>Thought to be caused by astronomical variations called Milankovitch cycles </li></ul><ul><li>Obliquity </li></ul><ul><li>Precession </li></ul><ul><li>Eccentricity </li></ul>
    92. 120. Milankovitch cycles <ul><li>The ice ages were due to the so-called Milankovitch cycles, that is a combination of the Earths eccentricity (the difference in distance to the sun throughout the year), the tilt of the Earth relative to the Earth-sun plane (difference summer – winter) and the time of the year when the Earth is closest to the sun. </li></ul>Milutin Milankovitch
    93. 121. The 3 Milankovitch cycles <ul><li>Precession : Orientation of the rotation axis with respect to Sun, 20 000 year cycle </li></ul><ul><li>Obliquity : tilt of rotation axis currently at 23.5º to plane of orbit, 40 000 year cycle </li></ul><ul><li>Eccentricity : elliptical shape of orbit, 100 000 year cycle </li></ul>
    94. 122. Precession <ul><li>Orientation of the rotation axis with respect to Sun 20 000 year cycle </li></ul>
    95. 123. Obliquity : tilt of rotation axis currently at 23.5º to plane of orbit 40 000 year cycle Eccentricity : elliptical shape of orbit, 100 000 year cycle
    96. 124. Last Ice Age <ul><li>18 000 years ago </li></ul><ul><li>Sea-level 120 m below present </li></ul><ul><li>Water bound up as continental icesheets </li></ul><ul><ul><li>Laurentide ice sheet of N.America </li></ul></ul><ul><ul><li>Fennoscandinavian ice sheet of N.Europe </li></ul></ul>
    97. 125. Present Occurrence of Ice <ul><li>Water bound up in ice as: </li></ul><ul><li>Continental icesheets </li></ul><ul><li>Sea ice: iceshelves or pack-ice and icebergs </li></ul><ul><li>Mountain glaciers </li></ul>
    98. 126. Present cryosphere <ul><li>Includes permafrost in tundra and snow at high altitudes </li></ul><ul><li>2% of total water volume </li></ul><ul><li>¾ of Earth’s freshwater </li></ul><ul><li>5.7% of surface of globe (seasonal fluctuations) </li></ul><ul><li>Most ice is stored in Antarctica </li></ul><ul><li>High albedo </li></ul>
    99. 127. Antarctic Icesheets and ice-shelves <ul><li>Mean thickness 2100m </li></ul><ul><li>Maximum thickness 4800m </li></ul><ul><li>East Antarctic icesheet is larger than West Antarctic icesheet </li></ul><ul><li>East Antarctic icesheet on bedrock above sea level </li></ul><ul><li>West Antarctic icesheet on rock below sealevel </li></ul><ul><li>Also Ross and Ronne ice-shelves over sea </li></ul>
    100. 128. Ice cores <ul><li>Icesheets are maintained by application of new coats of ice compressing previous layers </li></ul><ul><li>East Antarctic icesheet at 3000m is 250 000 years old </li></ul><ul><li>Analysis of cores of polar ice reveal previous composition of atmosphere </li></ul>
    101. 129. Greenland Plateau and Vostok, Antarctica Ice plateau on Greenland Vostok
    102. 130. Antarctic temperatures – during the last 400 000 years
    103. 131. Last four ice ages recorded in Antarctica                                                                                            
    104. 132. Icestreams and Icebergs <ul><li>Melting of icesheets </li></ul><ul><li>can form icestreams </li></ul><ul><li>or icebergs </li></ul>
    105. 133. Mountain Glaciers <ul><li>Frozen rivers </li></ul><ul><li>Flow slowly down with gravity </li></ul>
    106. 134. Glacial features <ul><li>U-shaped valleys </li></ul><ul><li>Truncated spurs </li></ul><ul><li>Hanging valleys </li></ul><ul><li>Moraines </li></ul><ul><li>Fjords </li></ul>
    107. 135. Glacier melt water <ul><li>Discharged into rivers, or directly into sea at high latitudes </li></ul>
    108. 136. Cryosphere and global change <ul><li>Seasonal glacial retreat </li></ul><ul><li>Retreat over several years maybe symptom of global change and warming </li></ul><ul><li>Increase number of icebergs in N. Atlantic </li></ul><ul><li>Decrease thickness of pack-ice in Arctic </li></ul>
    109. 137. Glacier retreat
    110. 139. The Nigard valley. The picture shows the retreat of the glacier. Photo: Bjørn Wold, NVE.
    111. 140. Changes in sea-ice thickness in the Arctic United Nations Environment Programme (UNEP) –Grid Arendal Overall change -1.3 m (40%) Positions with comparison USS Archerfish Measurements ’60s and ’90s
    112. 141. The destructive forces of Water
    113. 142. Floods <ul><li>River floods and ice jams </li></ul><ul><li>Coastal floods </li></ul><ul><li>Hurricanes and cyclones </li></ul><ul><li>Tsunamis </li></ul>
    114. 143. Floods and mortalities <ul><li>40% of deaths from natural disasters are due to floods </li></ul><ul><li>1965-85 half of Federal disasters in USA due to floods </li></ul><ul><li>Hurricane Agnes: 3.5 billion US, 120 lives </li></ul><ul><li>In USA, floods cost 2-4 Billion US dollars annually and about 200 lives </li></ul><ul><li>Figures much higher in some other parts of world </li></ul>
    115. 144. River floods <ul><li>1992 Pakistan and India: 2000 lives </li></ul><ul><li>China: 2297 BC </li></ul><ul><li>1332 AD 7 000 000 lives </li></ul><ul><li>1887 6 000 000 lives </li></ul><ul><li>Bangladesh: Ganges, Bramaputra and Megna rivers, low elevation frequent floods </li></ul><ul><li>Egypt: historical flooding of Nile </li></ul>
    116. 145. <ul><li>1993 Mississipi flood: 15 billion U$ 487 lives </li></ul>
    117. 146. Ice jams and melts <ul><li>1936 New England: 107 lives </li></ul>
    118. 147. Coastal floods <ul><li>High tides and storm surges 1953 North Sea </li></ul><ul><li>Tropical cyclones </li></ul><ul><ul><li>Hurricanes (Caribbean) </li></ul></ul><ul><ul><li>Typhoons (W. Pacific) </li></ul></ul><ul><li>Tsunami </li></ul>
    119. 148. Hurricanes <ul><li>1900 Galveston 10 000 lives </li></ul><ul><li>Hugo 1989 and Andrew 1992 30 billion US dollars </li></ul><ul><li>Formed over warm seas </li></ul>
    120. 149. Hurricane Hugo Digitized Charleston WSR-57 radar image of Hugo with superimposed winds Real-time winds measured onboard NOAA research aircraft flying into Hugo Wind velocity transmitted to NHC through a satellite link as eyewall hit coast Sustained winds of 155 mph at 10,000 feet and 135 mph at surface Higher gusts were estimated in area of landfall Image ID: wea00455, Historic NWS Collection Photographer: Dr. Frank Marks, AOML Hurricane Research Division
    121. 150. Hurricane Andrew Hurricane Andrew - visible satellite image taken by METEOSAT 3 This picture depicts Andrew during period of maximum intensity over Bahamas August 23,1992                             Image ID: wea00520, Historic NWS Collection
    122. 151. Hurricane Katrina, USA <ul><li>August 2005 </li></ul><ul><li>Levee holding back lake Pontchartrain breeched </li></ul><ul><li>New Orleans flooded </li></ul><ul><li>Science , Vol 309, Issue 5741, 1656-1659 , 9 September 2005 </li></ul><ul><li>Scientists' Fears Come True as Hurricane Floods New Orleans </li></ul><ul><li>John Travis </li></ul><ul><li>Katrina held few surprises for hurricane experts, who have repeatedly warned about the potential catastrophic consequences for New Orleans if such a storm were to make landfall nearby. </li></ul>
    123. 152. Lake Pontchartrain and New Orleans
    124. 153. New Orleans flooded
    125. 154. Breeched Levee
    126. 155. Breeched Levee
    127. 156. Loss of Wetlands An ambitious $14 billion plan known as Coast 2050 attempts to protect more than 10,000 square kilometers of Louisiana's wetlands, which are disappearing at a rate of up to 90 square kilometers per year, one of the highest rates of land loss in the world. But a number of unanswered scientific questions swirl around the plan. And it could run afoul of powerful interests in the shipping, petroleum, and fishing industries. Louisiana's Vanishing Wetlands: Going, Going ... Joel Bourne Science 2000 290: 456. (in Letters) [Full Text]
    128. 157. Altered Delta
    129. 158. Tropical cyclones in Indian Ocean <ul><li>Bangladesh: large areas only 3m altitude </li></ul><ul><li>1737: 1 000 000 lives </li></ul><ul><li>1876 </li></ul><ul><li>1970: 200 000 lives </li></ul><ul><li>1991: 100 000 lives </li></ul>
    130. 159. The 1998 flood in Bangladesh
    131. 160. Floods in Bangladesh
    132. 161. Tsunami <ul><li>caused by: </li></ul><ul><li>Earthquakes and Sea-floor displacement : e.g. 26 December 2004 Aceh </li></ul><ul><li>Landslides : e.g. Alaska 1957 </li></ul><ul><li>Volcanoes : e.g. Krakatau 1883 </li></ul>
    133. 162. Tsunami <ul><li>1792 Japan: 15 000 lives </li></ul><ul><li>1896 Japan: 27 000 lives </li></ul><ul><li>1957 Alaska: wave 60m devasted trees upland to 530m </li></ul><ul><li>1883 Krakatau: 36 000 lives </li></ul><ul><li>2004 Aceh and Indian Ocean: 300 000+ lives </li></ul>
    134. 163. 26 December 2004 off Aceh, Indonesia
    135. 164. Indonesia: lhoknga_iko_2004364
    136. 165. Sri Lanka_qbd_2004361
    137. 166. Sea Level Change <ul><li>Linked to climate change and ice ages </li></ul><ul><li>Last ice age, sea level 120m below present </li></ul><ul><li>Still enough ice in ice-sheets and glaciers to raise sea level by 66m! </li></ul><ul><li>A rise of only 5m would be catastrophic for Pacific Islands, Bangladesh, the Netherlands, Vietnam, Florida </li></ul><ul><li>Current estimates vary 20cm-1m by 2100 </li></ul><ul><li>Thermal expansion is main cause of rise </li></ul>
    138. 167. Water and Society <ul><li>Religions: water Gods, creation, floods </li></ul><ul><li>Ceremonies: baptism, cleansing before worship, sacred and holy water </li></ul>
    139. 168. Ancient Civilizations and Waterways <ul><li>Mesopotamia </li></ul><ul><li>India </li></ul><ul><li>China </li></ul><ul><li>Egypt </li></ul><ul><li>Tigris and Euphates </li></ul><ul><li>Ganges </li></ul><ul><li>Yellow River </li></ul><ul><li>Nile </li></ul>
    140. 169. Water and Health <ul><li>Cholera </li></ul><ul><li>Typhoid </li></ul><ul><li>Dysentry </li></ul><ul><li>Hepatitis A </li></ul><ul><li>Maleria and other mosquito-borne diseases (Dengue, West Nile fever) </li></ul>
    141. 170. Water as a Resource
    142. 171. The uses of water <ul><li>Domestic </li></ul><ul><ul><li>Drinking </li></ul></ul><ul><ul><li>Hygiene </li></ul></ul><ul><ul><li>Cleaning </li></ul></ul><ul><li>Industrial </li></ul><ul><ul><li>Heavy industry </li></ul></ul><ul><ul><li>Light industry </li></ul></ul><ul><ul><li>Food industry </li></ul></ul><ul><ul><li>Power generation </li></ul></ul><ul><li>Recreation </li></ul><ul><ul><li>Bathing </li></ul></ul><ul><ul><li>Sailing </li></ul></ul><ul><li>Agricultural </li></ul><ul><ul><li>Irrigation </li></ul></ul><ul><ul><li>Aquaculture </li></ul></ul><ul><ul><li>Fisheries </li></ul></ul>
    143. 172. Water and Energy <ul><li>Hydroelectric power </li></ul><ul><li>Water as a “fuel” by splitting </li></ul><ul><ul><li>Electolysis, </li></ul></ul><ul><ul><li>Photolysis, </li></ul></ul><ul><ul><li>Photosynthesis </li></ul></ul><ul><ul><li>H-O fuel cells </li></ul></ul><ul><li>Tidal mills and barrages </li></ul><ul><li>Ocean currents </li></ul>
    144. 173. Water as a scarce resource <ul><li>Uneven distribution of rainfall </li></ul>
    145. 174. <ul><li>2/3 of rainfall flows to sea </li></ul>
    146. 175. Global use of water <ul><li>Tripled between 1950-90 </li></ul><ul><li>Half of available runoff used by 1996 </li></ul>
    147. 179. Use of water by sector differs
    148. 180. Use of domestic water differs… <ul><li>Uganda and Burundi 5-25 Liters per day per person </li></ul><ul><li>Europe 100 to 260 liters per day per person </li></ul><ul><li>USA 400-500 liters per day </li></ul><ul><li>Same water quality for brushing teeth, flushing toilet and washing car </li></ul>
    149. 181. Agriculture <ul><li>Most increases in crop production due to irrigation </li></ul>
    150. 183. Increasing water stress
    151. 184. Abuses of water <ul><li>Wastage in distribution, leaks e.g. UK </li></ul><ul><li>Inefficient irrigation e.g. Middle East </li></ul><ul><li>Over extraction and salinization e.g. Mediterranean </li></ul><ul><li>Desertification e.g. MidWest dust bowl Sahel </li></ul><ul><li>Pollution </li></ul>
    152. 185. Pollution <ul><li>Drinking water can be affected </li></ul><ul><li>Pesticides, Herbicides, Fungicides </li></ul><ul><li>Fertilizers </li></ul><ul><li>Industrial PCBs (paints, plastics, adhesives) </li></ul><ul><li>Metals from mines and industry </li></ul><ul><li>Hydrocarbons and Crude oil </li></ul><ul><li>Sewage pathogens </li></ul><ul><li>Organic Matter </li></ul><ul><li>Detergents </li></ul><ul><li>Acid rain </li></ul>
    153. 186. New or recycled water <ul><li>Recycle grey water for agriculture </li></ul><ul><li>Desalination </li></ul><ul><li>Shipping water from countries where it is abundant e.g. Alaska to China, Norway to S. Europe </li></ul>
    154. 187. The Global International Waters Assessment <ul><li>GIWA </li></ul><ul><li>Comprehensive strategic assessment </li></ul><ul><li>Designed to identify priorities for remedial and mitigatory actions in international waters. </li></ul>
    155. 188. GIWA's assessment tools Incorporate 5 major environmental concerns and application of the DPSIR framework.
    156. 189. DPSIR framework <ul><li>Driving forces </li></ul><ul><li>Pressures </li></ul><ul><li>Impacts </li></ul><ul><li>State </li></ul><ul><li>Responses </li></ul>
    157. 190. <ul><li>Black Sea, </li></ul><ul><li>Amazon, </li></ul><ul><li>Gr. Barrier Reef, </li></ul><ul><li>Agulhas Current </li></ul>GIWA Case Studies
    158. 191. Water and Life
    159. 192. Carbon life-forms… <ul><li>All known life-forms are C-based </li></ul><ul><li>Many other elements essential for organic (C) life, e.g. N, P </li></ul><ul><li>All known life-forms also require water </li></ul><ul><li>Many organisms more than 70% water, some more than 90% </li></ul><ul><li>Humans require min. 1 liter per day </li></ul>
    160. 193. The Beginning of Life <ul><li>~3.8 billion years ago. </li></ul><ul><li>Atmosphere contained N, CO 2 and water as well as H 2 S and CH 4 from volcanoes </li></ul><ul><li>Very little oxygen, anoxic, reducing </li></ul><ul><li>Current scientific theory: first life-forms were aquatic in shallow lagoons, or hydrothermal vents </li></ul>
    161. 194. Early life forms <ul><li>Oldest fossils: </li></ul><ul><ul><li>Rocks in SW Greenland </li></ul></ul><ul><ul><li>Australian Stromatolites 3.5 billion years </li></ul></ul><ul><li>First life-forms: </li></ul><ul><ul><li>anaerobic heterotrophs using simple organic molecules available by glycolysis or fermentation </li></ul></ul><ul><ul><li>chemosynthetic autotrophs using H 2 S </li></ul></ul><ul><ul><li>photosynthetic autotrophs using H 2 S </li></ul></ul>
    162. 195. Oxygen and early life-forms <ul><li>Oxygen produced by one type of photosynthesis </li></ul><ul><li>Uses H 2 O as a proton donor instead of H 2 S </li></ul><ul><li>Oxygen is oxidating, reactive, corrosive gas </li></ul><ul><li>Oxygen is TOXIC to aerobic life-forms </li></ul><ul><li>Oxygen accumulated slowly in the atmosphere </li></ul><ul><li>Permited the evolution of facultative anerobes and aerobic heterotrophs and </li></ul><ul><li>Aerobic respiration is far more energetic than fermentation </li></ul>
    163. 196. Aquatic life-forms <ul><li>Aquatic life-forms usually restricted in their distribution to fresh or salt water </li></ul><ul><li>Osmotic pressure one of the colligative properties of water </li></ul><ul><li>Special adaptations needed for estuarine organisms to survive salinity changes and migratory organisms such as eels and salmon </li></ul>
    164. 197. Terrestrial plant-forms <ul><li>Photosynthetic cyanobacteria probably first organisms to survive on land </li></ul><ul><li>460 million years ago bryophytes (mosses and liverworts) and ferns </li></ul><ul><li>325 million years ago tropical forests </li></ul><ul><li>Vascular plants “higher” supported by water-based fluids xylem and phloem </li></ul><ul><li>Depend on properties of water such as osmosis and capillary action </li></ul><ul><li>Transpiration from plants is important in Hydrological cycle </li></ul>
    165. 198. Terrestrial animal-forms <ul><li>Many land-based animals need special adaptations to live out of water such e.g. </li></ul><ul><ul><li>Molluscs such as gastropod snails </li></ul></ul><ul><ul><li>Crustacea such as crabs </li></ul></ul><ul><li>Amphibians first vertebrates on land </li></ul><ul><li>Animals also have many water based fluids such as cytoplasm, blood plasma and lymph </li></ul>