WATER: GLOBAL RESOURCES AND POLLUTION APES CHAPTERS 13 & 20

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1 WATER: GLOBAL RESOURCES AND POLLUTION APES CHAPTERS 13 & 20

2 OUR THIRSTY WORLD

3 WHY SHOULD WE CARE ABOUT WATER?

4 FRESHWATER RESOURCES WATER IS A VITAL RESOURCE THAT SUSTAINS LIFE, MODERATES CLIMATE, SHAPES THE EARTH S SURFACE, AND PROVIDES HABITAT FOR MANY ORGANISMS. ALTHOUGH WATER HAS AN AMAZING ABILITY TO DILUTE AND REMOVE MANY POLLUTANTS, IT CANNOT PURIFY OR DISPERSE ALL THE HEAVY CONCENTRATION OF CONTAMINANTS RESULTING FROM THE GROWING HUMAN POPULATION AND THE INCREASING INPUT OF TOXINS GENERATED BY AGRICULTURAL, INDUSTRIAL, AND RESIDENTIAL ACTIVITIES.

5 FRESHWATER RESOURCES WATER POLLUTION FROM THESE ACTIVITIES HAS HAD A DEVASTATING IMPACT ON HUMAN HEALTH. MANY PEOPLE IN DEVELOPING NATIONS LACK ADEQUATE ACCESS TO CLEAN DRINKING WATER. THE WORLD HEALTH ORGANIZATION ESTIMATES THAT OVER 1.6 MILLION PEOPLE DIE EACH YEAR FROM PREVENTABLE DISEASES CAUSED BY CONTAMINATED DRINKING WATER.

6 FRESHWATER RESOURCES WATER RESOURCES AVAILABLE FOR HUMAN USE ARE VERY LIMITED. MUCH LESS THAN 1% OF THE GLOBAL WATER SUPPLY IS READILY AVAILABLE AS FRESHWATER.

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8 SHOW ME THE WATER!

9 GROUNDWATER SOME PRECIPITATION INFILTRATES THE GROUND AND PERCOLATES DOWNWARD THROUGH THE SOIL, GRAVEL, AND POROUS ROCK LAYERS UNTIL IT REACHES A ROCK LAYER THAT IS NOT PERMEABLE. THE WATER THAT FILLS THESE UNDERGROUND POROUS SPACES IS KNOWN AS GROUNDWATER.

10 GROUNDWATER TYPICALLY THE FIRST FEW LAYERS BELOW EARTH S SURFACE TRAP MOSTLY AIR RATHER THAN WATER AND ARE KNOWN AS THE ZONE OF AERATION. THE DEEPER SUBSURFACE LAYERS THAT FILL ALL AVAILABLE POROUS SPACE WITH WATER ARE KNOWN AS THE ZONE OF SATURATION.

11 GROUNDWATER THE UPPER LIMIT OF THE ZONE OF SATURATION IS KNOWN AS THE WATER TABLE. THE HEIGHT OF THE WATER TABLE FLUCTUATES. IT CAN LOWER IN DRY SEASONS OR BECAUSE OF OVER-WITHDRAWAL BY HUMANS OR CAN RISE DURING RAINY (WET) SEASONS.

12 GROUNDWATER AQUIFERS ARE DEEP UNDERGROUND LAYERS OF POROUS ROCK MATERIAL, GRAVEL, SAND, SILT, OR CLAY WHERE GROUNDWATER FLOWS. GROUNDWATER IN AQUIFERS IS REPLENISHED IN 2 WAYS: NATURAL RECHARGE THROUGH PERCOLATION OF PRECIPITATION OR BY LATERAL RECHARGE THROUGH MOVEMENT OF WATER FROM RIVERS AND STREAMS.

13 GROUNDWATER SOME AQUIFERS RECEIVE VERY LITTLE RECHARGE AND ARE REFERRED TO AS NON-RENEWABLE AQUIFERS. WATER MINING IS A TERM USED TO DESCRIBE WITHDRAWALS FROM THESE AQUIFERS SINCE EVENTUALLY THE SUPPLY WILL BE DEPLETED ENTIRELY.

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16 SURFACE WATER SURFACE WATER EXISTS AS RIVERS, LAKES, WETLANDS, ESTUARIES, AND THE OCEAN. RECHARGE TO THESE WATERS IS IN THE FORM OF SURFACE RUNOFF FROM PRECIPITATION AND SNOWMELT THAT DOES NOT INFILTRATE INTO THE SOIL LAYERS.

17 SURFACE WATER A WATERSHED, OR DRAINAGE BASIN, IS THE LAND SURROUNDING THESE BODIES OF WATER THAT CONTRIBUTE TO SURFACE RUNOFF. BODIES OF SURFACE WATER ARE ALSO RECHARGED LATERALLY FROM GROUNDWATER SOURCES. THEREFORE, IF GROUNDWATER IS WITHDRAWN FASTER THAN IT IS REPLENISHED THIS CAN REDUCE THE VOLUME OF SURFACE WATER IN RIVERS, LAKES, AND STREAMS.

18 WATER EQUITY, SHORTAGES, & FLOODS GLOBALLY, THE MAIN USES OF GROUNDWATER AND SURFACE WATER ARE: 70% FOR IRRIGATION 20% FOR INDUSTRIAL PROCESSES ~10% FOR HUMAN CONSUMPTION

19 TROUBLED WATERS

20 WATER EQUITY, SHORTAGES, & FLOODS AFFLUENT NATIONS USE LARGE AMOUNTS OF WATER TO PRODUCE HUGE AMOUNTS OF ELECTRICITY, A VAST ARRAY OF CONSUMER GOODS, AND FOOD PRODUCTS. THEY ALSO TYPICALLY HAVE EASY ACCESS TO WATER FOR RESIDENTIAL NEEDS SUCH AS FLUSHING TOILETS, BATHS AND SHOWERS, WASHING MACHINES, AND DISHWASHERS.

21 WATER EQUITY, SHORTAGES, & FLOODS UNLIKE AFFLUENT NATIONS, DEVELOPING COUNTRIES OFTEN LACK ACCESS TO CLEAN DRINKING WATER. MANY PEOPLE IN DEVELOPING NATIONS LIVE WITHOUT ELECTRICITY OR RUNNING WATER. MOST OF THE FRESHWATER IN DEVELOPING NATIONS IS USED FOR CROP PRODUCTION IN THE FORM OF IRRIGATION WATER.

22 WATER WALK

23 WATER EQUITY, SHORTAGES, & FLOODS A MAJOR ISSUE FACING THE HUMAN POPULATION REGARDING FRESHWATER RESOURCES IS UNEQUAL DISTRIBUTION. FOR EXAMPLE, CANADA HAS 20% OF THE WORLD S LIQUID FRESHWATER SUPPLY BUT ONLY 0.5% OF THE WORLD S POPULATION. ASIA HAS ONLY 30% OF THE WORLD S LIQUID FRESHWATER SUPPLY BUT 60% OF THE WORLD S POPULATION.

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26 WATER EQUITY, SHORTAGES, & FLOODS WATER SUPPLIES ARE NOT EVENLY DISTRIBUTED WITHIN NATIONS. THE WESTERN HALF OF THE UNITED STATES UTILIZES THE MAJORITY OF ITS WATER WITHDRAWALS FOR IRRIGATION. THESE STATES ARE ARID OR SEMIARID, RECEIVE LESS PRECIPITATION, AND HAVE HIGHER EVAPORATION RATES THAN THE EASTERN UNITED STATES.

27 WATER EQUITY, SHORTAGES, & FLOODS SOME REGIONS OF THE WESTERN UNITED STATES ALSO EXPERIENCE RECURRING DROUGHTS. DROUGHTS ARE LONG PERIODS OF TIME WHEN REGIONS RECEIVE 30% OR LESS OF THEIR AVERAGE ANNUAL PRECIPITATION. ALL OF THESE FACTORS PLAY A ROLE IN CREATING SEVERE WATER SHORTAGES IN THE WESTERN HALF OF THE UNITED STATES.

28 WATER EQUITY, SHORTAGES, & FLOODS IN COMPARISON, THE EASTERN HALF OF THE UNITED STATES USUALLY DOES NOT SUFFER FROM WATER SHORTAGES DUE TO HIGHER LEVELS OF ANNUAL PRECIPITATION AND REDUCED EVAPORATION RATES.

29 WATER EQUITY, SHORTAGES, & FLOODS WITH INCREASING POPULATION COMES A GROWING DEMAND FOR WATER RESOURCES TO PRODUCE MORE FOOD, SUPPLY MORE ELECTRICITY, MAKE MORE CONSUMER GOODS, AND FOR HUMAN CONSUMPTION. THIS WILL CONTINUE TO INTENSIFY WATER SHORTAGES AND WILL ESCALATE ALREADY HEATED BATTLES OVER WATER RIGHTS.

30 WATER EQUITY, SHORTAGES, & FLOODS WHILE SOME REGIONS BATTLE A LACK OF WATER, OTHERS EXPERIENCE HEAVY RAINS OR RAPIDLY MELTING SNOWPACK. FLOODS ARE RESPONSIBLE FOR CAUSING BILLIONS OF DOLLARS WORTH OF DAMAGE TO INFRASTRUCTURE AND FOR THE LOSS OF THOUSANDS OF LIVES EACH YEAR.

31 WATER EQUITY, SHORTAGES, & FLOODS FLOODPLAINS ARE FLAT LAND AREAS THAT ARE PERIODICALLY FLOODED WITH NUTRIENT-RICH SILT FROM THE NEARBY RIVERS AND STREAMS THEY SURROUND. HISTORICALLY, PEOPLE HAVE SETTLED ON FLOODPLAINS BECAUSE OF THEIR FERTILE SOILS AND READILY AVAILABLE WATER SUPPLIES.

32 WATER EQUITY, SHORTAGES, & FLOODS WHEN FLOODPLAINS ARE DEVELOPED, MUCH OF THE WATER-ABSORBING RIPARIAN VEGETATION IS REMOVED, AND THE CAPACITY OF THE WETLANDS TO ACT AS A NATURAL FLOOD BARRIER IS DESTROYED. THESE ACTIVITIES ARE ESPECIALLY DANGEROUS IN DENSELY POPULATED AREAS THAT LIE NEAR OR BELOW SEA LEVEL. FOR EXAMPLE, NEW ORLEANS EXPERIENCED DEVASTATING FLOODS FROM HURRICANE KATRINA, MADE WORSE BY THE REMOVAL OF COASTAL WETLANDS.

33 NATURAL FLOOD PROTECTION

34 SURFACE WATER & GROUNDWATER DEPLETION: USING GROUNDWATER RESOURCES POPULATIONS RELY HEAVILY ON AQUIFER RESOURCES (GROUNDWATER) FOR IRRIGATION AND DRINKING WATER. SUSTAINABILITY OF AQUIFERS DEPENDS ON THE RATE OF RECHARGE OF SYSTEM VERSUS RATE OF WITHDRAWAL BY HUMANS. OVERDRAFT IS A CONDITION THAT OCCURS WHEN WITHDRAWALS EXCEED RECHARGE AND WATER TABLES BEGIN TO FALL.

35 SURFACE WATER & GROUNDWATER DEPLETION: USING GROUNDWATER RESOURCES OVERDRAFT FROM THE AQUIFER CAN CAUSE THE LAND ABOVE THE GROUNDWATER RESERVOIR TO SINK OR COLLAPSE; THIS IS KNOWN AS LAND SUBSIDENCE. A TYPE OF LAND SUBSIDENCE CALLED A SINKHOLE OCCURS SUDDENLY WHEN THE TOP OF AN UNDERGROUND CAVERN COLLAPSES. OVERDRAFT IN COASTAL AREAS CAN FORCE THE FLOW OF SALTWATER INTO FRESHWATER AQUIFERS. THIS SALTWATER INTRUSION MAKES THE AQUIFER UNUSABLE FOR BOTH DRINKING AND IRRIGATION.

36 WHAT IS SALTWATER INTRUSION?

37 OGALLALA AQUIFER PROVIDES ALMOST ONE-THIRD OF IRRIGATION WATER TO SEVERAL STATES IN THE MIDWESTERN UNITED STATES, HELPING TO MAKE THEM HIGHLY PRODUCTIVE AGRICULTURAL LANDS. EXCESS WITHDRAWAL RATES AND AN EXTREMELY SLOW RECHARGE RATE HAS LOWERED THE WATER TABLE IN THIS AQUIFER BY AS MUCH AS 30 METERS. THE REDUCED VOLUME OF WATER IN THE AQUIFER HAS CAUSED LAND SUBSIDENCE AND DECREASED DISCHARGE INTO WETLANDS AND ESTUARIES, THREATENING BIODIVERSITY IN THESE ECOSYSTEMS.

38 OGALLALA AQUIFER

39 HOW TO PROTECT GROUNDWATER RESOURCES 1. SUBSIDIZE WATER CONSERVATION STRATEGIES. 2. IMPLEMENT WATER CONSERVATION PRACTICES IN RESIDENTIAL HOMES. 3. INCREASE THE PRICE TO DISCOURAGE WASTE. 4. REDUCE THE NUMBER OF WATER-INTENSIVE CROPS BEING GROWN, ESPECIALLY IN ARID AND SEMI-ARID REGIONS.

40 SURFACE WATER & GROUNDWATER DEPLETION: USING SURFACE WATER RESOURCES LIKE AQUIFERS, SURFACE WATERS (LAKES, RIVERS, STREAMS) AROUND THE WORLD HAVE PROVIDED THE MEANS FOR IRRIGATION AND DRINKING WATER SUPPLIES. SURFACE WATER RESOURCES ARE EASILY ACCESSIBLE AND THEREFORE HAVE BEEN UTILIZED IN A VARIETY OF WAYS INCLUDING HYDROELECTRIC POWER.

41 HYDROELECTRIC POWER IN MANY AREAS, FAST-FLOWING RIVERS ARE DAMMED TO CREATE FRESHWATER RESERVOIRS AND IN MANY CASES PROVIDE HYDROELECTRIC POWER. ONCE A RIVER IS DAMMED THE TERRESTRIAL AREA BEHIND THE DAM WILL FLOOD, CREATING A RESERVOIR THAT STORES THE SURFACE WATER RUNOFF THAT WOULD HAVE ONCE FLOWED DIRECTLY INTO THE RIVER. HYDROELECTRIC POWER HAS MANY ADVANTAGES AND DISADVANTAGES.

42 ADVANTAGES OF HYDROELECTRIC POWER NO CARBON DIOXIDE EMISSIONS. PROVIDES IRRIGATION AND DRINKING WATER. CAN PROVIDE FLOOD CONTROL. PROVIDES CHEAP ELECTRICITY. RESERVOIR CAN BE USED FOR RECREATION.

43 DISADVANTAGES OF HYDROELECTRIC POWER DISPLACES PEOPLE LIVING BEHIND THE DAM. DECREASES NUTRIENT-RICH SILT DOWNSTREAM. FISH HARVEST BELOW DAM DECREASES. DISRUPTS MIGRATION PATTERNS OF SOME FISH. LOSS OF WATER BY EVAPORATION.

44 COLORADO RIVER BASIN THE COLORADO RIVER FLOWS FROM THE ROCKY MOUNTAINS IN COLORADO TO THE GULF OF CALIFORNIA. THE COLORADO RIVER PROVIDES MUCH NEEDED WATER TO THE SOUTHWESTERN UNITED STATES AND MEXICO, AN ARID AND SEMI-ARID REGION OFTEN PLAGUED BY DROUGHTS AND WATER SHORTAGES. THE RIVER PROVIDES DRINKING WATER TO URBAN AREAS SUCH AS LOS ANGELES, SAN DIEGO, AND LAS VEGAS. IT ALSO PROVIDES IRRIGATION TO FARMS THAT PRODUCE ~15% OR OUR NATION S CROPS.

45 COLORADO RIVER BASIN GOVERNMENT SUBSIDIES FOR AGRICULTURE HAVE HISTORICALLY INCREASED DEMAND FOR IRRIGATION WATER IN THIS AREA. 14 MAJOR DAMS THAT HAVE BEEN ERECTED ALONG THE RIVER HAVE CREATED WATER RESERVOIRS FOR THIS DESERT REGION. EXCESSIVE WITHDRAWALS FOR WATER IN THIS AREA, PRIMARILY FOR IRRIGATION, HAVE LED TO MASSIVE VOLUME REDUCTIONS IN THE RIVER.

46 COLORADO RIVER BASIN AT TIMES, THE RIVER DOES NOT EVEN MAKE IT TO THE GULF OF CALIFORNIA, AND EVEN IF IT DOES, THE RESIDUAL WATER IS SO SALINATED FROM IRRIGATION RUN OFF THAT IT IS UNUSABLE. THIS HAS LED TO INTERNATIONAL DISPUTES AND HAS CAUSED THE UNITED STATES TO CONSTRUCT DESALINATION PLANTS TO CLEAN THE WATER BEFORE RELEASING IT TO MEXICO. CONTINUED CLIMATE CHANGE MAY ALSO REDUCE ANNUAL SNOWMELT, FURTHERING WATER SHORTAGE PROBLEMS.

47 COLORADO RIVER BASIN 2 MAJOR DAMS ARE THE HOOVER DAM, WHICH CREATES THE LAKE MEAD RESERVOIR, AND THE GLEN CANYON DAM, WHICH CREATES THE LAKE POWELL RESERVOIR.

48 CHASING RIVERS PART 1: THE COLORADO RIVER

49 THREE GORGES DAM, CHINA BUILT ALONG THE YANGTZE RIVER IN CHINA, IS THE WORLD S LARGEST HYDROELECTRIC DAM. THE HYDROELECTRIC DAM IS CAPABLE OF PRODUCING THE SAME ENERGY OUTPUT OF 22 COAL-BURNING POWER PLANTS, WITH NO CARBON DIOXIDE EMISSIONS. HOWEVER, SOME SCIENTISTS SAY THIS SAVINGS OF CO 2 EMISSIONS WILL BE OFFSET BY METHANE GASES BEING RELEASED FROM THE DECOMPOSITION OF VEGETATION IN THE LARGE RESERVOIR.

50 THREE GORGES DAM, CHINA

51 WATER TRANSFER PROJECTS SINCE WATER IS NOT EVENLY DISTRIBUTED WITHIN AND AMONG NATIONS, MANY COUNTRIES AND INDIVIDUAL U.S. STATES HAVE CREATED WATER TRANSFER PROJECTS TO PROVIDE WATER TO AREAS WITH LIMITED SUPPLY. MANY OF THESE PROJECTS HAVE RESULTED IN A DEVASTATING VOLUME OF WATER LOST IN ECOSYSTEMS SUCH AS LAKES, WETLANDS, AND ESTUARIES. THIS CAN RESULT IN THESE ECOSYSTEMS BEING UNABLE TO SUPPORT A DIVERSITY OF LIFE.

52 ARAL SEA THE ARAL SEA, LOCATED IN THE FORMER SOVIET UNION, HAS BEEN DECLINING IN VOLUME SINCE THE 1960S. SEVERAL FACTORS HAVE CONTRIBUTED TO THIS SHRINKING VOLUME: LOCATED IN AN AREA OF ASIA WITH ONE OF DRIEST CLIMATES. CROP PRODUCTION IS LIMITED BY WATER SUPPLIES FROM THE ARAL SEA. RECURRING DROUGHTS, LIMITED PRECIPITATION, AND HIGH EVAPORATION EQUAL SLOW RECHARGE.

53 ARAL SEA TRANSFER OF WATER FROM THE ARAL SEA HAS BECOME AN ECOLOGICAL TRAGEDY. MAJOR WATER LOSS HAS INCREASED SALINITY LEVELS TO 7 TIMES THE ORIGINAL LEVEL, WHICH HAS DESTROYED WETLANDS. REDUCTION IN SIZE HAS ALTERED LOCAL CLIMATE; THE SEA ACTED AS A THERMAL BUFFER THAT MODERATED CLIMATE IN THE REGION. NOW, PRECIPITATION IS REDUCED, SUMMERS ARE HOTTER AND DRIER, WINTERS ARE COLDER. ECONOMY NEGATIVELY IMPACTED DUE TO DECIMATED FISH POPULATIONS AND DECREASED CROP PRODUCTION.

54 ARAL SEA: MANMADE DISASTER

55 CALIFORNIA WATER TRANSFER PROJECT MASSIVE WATER TRANSFER PROJECT THAT USES A SERIES OF PUMPS, AQUEDUCTS, AND DAMS TO MOVE WATER FROM WATER-RICH NORTHERN CALIFORNIA TO THE DESERT REGIONS IN SOUTHERN CALIFORNIA. THIS IS ONE OF THE WORLD S LARGEST WATER TRANSFER PROJECTS; HOWEVER, IT HAS COME AT THE EXPENSE OF MANY OF THE STATE S LAKE ECOSYSTEMS. EX: IN THE 1980S, SCIENTISTS DISCOVERED THAT MONO LAKE HAD LOST OVER 30% OF ITS ORIGINAL SURFACE AREA. COURT BATTLES RESULTED IN RESTRICTION OF WITHDRAWAL FROM MONO LAKE IN THE 1990S. RECENT MEASUREMENTS SHOW LAKE STEADILY GAINING VOLUME.

56 CHINA S WATER TRANSFER PROJECT THE SOUTH-NORTH WATER TRANSFER PROJECT WILL USE A SERIES OF DAMS, CANALS, AND RESERVOIRS TO PUMP WATER FROM THE SOUTHERN YANGTZE RIVER BASIN TO CHINA S MORE POPULATION NORTHERN PROVINCES. THIS WILL ALSO PROVIDE DRINKING WATER FOR MAJOR CITIES IN CHINA SUCH AS BEIJING.

57 WATER CONSERVATION THE HUMAN POPULATION HAS GENERALLY VIEWED WATER AS A CHEAP, ABUNDANT, AND RENEWABLE RESOURCE. HOWEVER, INEFFICIENT PRACTICES AND EXCESSIVE WITHDRAWALS OF BOTH GROUNDWATER AND SURFACE WATERS ARE INCREASING POTENTIAL FOR DANGEROUS WATER SHORTAGES AROUND THE WORLD. THE CHEAPEST AND FASTEST WAYS TO IMPROVE WATER CONSERVATION ARE: TO REDUCE THE LOSS OF IRRIGATION WATER BY EVAPORATION. FIX RESIDENTIAL AND INDUSTRIAL PIPE LEAKS.

58 IMPROVING IRRIGATION PRACTICES ALMOST 40% OF THE FRESHWATER USED IN THE UNITED STATES GOES TO IRRIGATE CROPS. FLOOD IRRIGATION IS USED IN SOME PARTS OF THE UNITED STATES AND IS A COMMON PRACTICE IN DEVELOPING COUNTRIES. THIS METHOD RELIES ON PUMPING LARGE AMOUNTS OF WATER DIRECTLY ONTO AGRICULTURAL LAND AND ALLOWING IT TO FLOW BY GRAVITY INTO DITCHES IN THE SOIL WHERE THE CROPS CAN THEN ABSORB THE WATER. UNFORTUNATELY, ALMOST HALF OF THE WATER NEVER REACHES THE PLANTS; IT IS LOST TO EVAPORATION AND SURFACE RUNOFF.

59 FLOOD IRRIGATION

60 IMPROVING IRRIGATION PRACTICES DRIP IRRIGATION, ALSO KNOWN AS MICRO-IRRIGATION, IMPROVES EFFICIENCY BY DELIVERING SMALLER VOLUMES OF WATER MORE DIRECTLY TO CROP ROOTS FOR ABSORPTION. A SERIES OF PLASTIC PIPES CONTAINING MANY SMALL HOLES TO RELEASE WATER ARE RUN ALONG THE CROP ROWS OR BURIED IN SOIL ALONG THE ROOT LINE. THIS DECREASES THE CHANCE OF EVAPORATION AND IMPROVES EFFICIENCY UP TO 95%. ALTHOUGH DRIP IRRIGATION IS MORE EXPENSIVE THAN TRADITIONAL FLOOD IRRIGATION, IT CAN INCREASE CROP YIELDS FROM 20% TO 90%.

61 DRIP IRRIGATION

62 IMPROVING IRRIGATION PRACTICES CENTER-PIVOT SYSTEMS CONSIST OF NUMEROUS METAL FRAMES ROLLING ON WHEELS THAT EXTEND LARGE WATER PIPES OUT OVER CROPS. LOW-PRESSURE SPRINKLERS IN THE PIPES DELIVER WATER DIRECTLY TO THE CROPS, AS AN ELECTRIC MOTOR MOVES THE METAL FRAME AROUND THE FIELD IN A CIRCULAR MOTION WITH THE WATER SOURCE (SUCH AS A WELL) AT THE CENTER. THIS TYPE OF SYSTEM CAN INCREASE EFFICIENCY UP TO 80%. A LOW-ENERGY PRECISION APPLICATION (LEPA) SPRINKLER SYSTEM IS A TYPE OF CENTER-PIVOT THAT INCREASES EFFICIENCY UP TO 95% BY APPLYING DIRECTLY TO ROOTS.

63 CENTER-PIVOT IRRIGATION

64 OTHER METHODS OF IRRIGATION WATER CONSERVATION 1. IRRIGATE CROPS WITH TREATED URBAN WASTEWATER. 2. IRRIGATE AT NIGHT TO REDUCE WATER LOST TO EVAPORATION. 3. DON T GROW WATER-THIRSTY CROPS IN ARID AND SEMI-ARID REGIONS. 4. INCREASE GOVERNMENT SUBSIDIES FOR EFFICIENT IRRIGATION PRACTICES. 5. USE SOIL MOISTURE MONITORS TO IRRIGATE ONLY WHEN NEEDED. 6. INCREASE USE OF POLYCULTURE OR ORGANIC FARMING PRACTICES INSTEAD OF MONOCULTURE. 7. USE RAINWATER HARVESTING FOR SMALLER AGRICULTURAL FIELDS (DEVELOPING COUNTRIES).

65 IMPROVING INDUSTRIAL & RESIDENTIAL WATER CONSERVATION WATER IS A KEY COMPONENT IN MANY INDUSTRIAL PROCESSES SUCH AS PETROLEUM REFINING, FOOD PROCESSING, PAPER AND STEEL PRODUCTION, ETC. RESIDENTIAL USES INCLUDE WATER FOR LAWN SPRINKLING, DRINKING, BATHING, CLOTHES WASHING, AND OTHER HOUSEHOLD USES. THE LARGEST USE OF DOMESTIC WATER USE COMES FROM FLUSHING TOILETS! CURRENT U.S. STANDARDS REQUIRE THAT TOILETS HAVE NO MORE THAN 1.6 GALLONS OF WATER PER FLUSH. THIS IS STILL VERY WASTEFUL.

66 IMPROVING INDUSTRIAL & RESIDENTIAL WATER CONSERVATION ACCORDING TO THE UNITED NATIONS, THE LARGEST SOURCE OF WATER LOSS IN BOTH INDUSTRIAL AND RESIDENTIAL PRACTICES IS LEAKS IN PIPES, VALVES, AND WATER MAINS! THERE IS LITTLE INCENTIVE TO FIX BECAUSE THE WATER LOST COSTS LESS THAN THE COST TO FIX THE LEAKS. GREY WATER SYSTEMS ARE NOW BEING USED IN SOME HOMES. THESE SYSTEMS USE WATER FROM SHOWERS, BATHTUBS, DISHWASHERS, AND CLOTHES WASHERS TO WATER LAWNS, WASH CARS, OR FLUSH TOILETS. GO GREY!

67 OTHER METHODS OF WATER CONSERVATION FOR INDUSTRIAL AND RESIDENTIAL PRACTICES 1. FIX LEAKS IN PIPES AND WATER MAINS. 2. INCREASE PRICES FOR WATER. 3. REQUIRE THE USE OF WATER METERS. 4. RECYCLE THE WATER USED IN INDUSTRIAL PROCESSES. 5. USE LOW-FLOW SHOWERHEADS AND LOW-VOLUME TOILETS.

68 INCREASING FRESHWATER SUPPLIES MANY COUNTRIES ARE LOOKING FOR WAYS TO INCREASE THEIR LIQUID FRESHWATER SUPPLIES BY UTILIZING AN ABUNDANT SOURCE, SALTWATER. DESALINATION IS A PROCESS THAT REMOVES DISSOLVED SALTS FROM OCEAN WATER OR FROM BRACKISH SEAS AND LAKES. THIS CAN PROVIDE VALUABLE FRESHWATER IN AREAS FACING WATER SHORTAGES, ESPECIALLY IN ARID REGIONS SUCH AS THE MIDDLE EAST AND NORTHERN AFRICA.

69 INCREASING FRESHWATER SUPPLIES 2 METHODS OF DESALINATION ARE: REVERSE OSMOSIS ALSO CALLED MICROFILTRATION, REVERSE OSMOSIS USES EXTERNAL PRESSURE TO PUSH SALINE WATER THROUGH MEMBRANES THAT SEPARATE SOLUTES (SALT) FROM SOLVENT (WATER). DISTILLATION THIS PROCESS INVOLVES HEATING SALTWATER UNTIL EVAPORATION BEGINS. THE STEAM IS COLLECTED AND CONDENSES AS FRESHWATER AS THE SALTS HAVE BEEN LEFT BEHIND IN SOLID FORM.

70 INCREASING FRESHWATER SUPPLIES WHILE DESALINATION PROVIDES FRESHWATER RESOURCES TO AREAS IN SHORT SUPPLY, IT ALSO HAS MANY DRAWBACKS AS WELL. BOTH DESALINATION PROCESSES PRODUCE LARGE AMOUNTS OF BRINY WASTEWATER THAT MUST BE DISPOSED OF. IT POSES A RISK TO WILDLIFE IF DUMPED IN OCEAN WATERS AND IT COULD POLLUTE GROUNDWATER IF DISPOSED OF ON LAND. ALSO, LARGE SCALE DESALINATION IS VERY EXPENSIVE AND NOT A REALISTIC OPTION FOR DEVELOPING NATIONS.

71 BOZEMAN SCIENCE: WATER RESOURCES

72 WATER POLLUTION SOURCES & TYPES WATER IS CONSIDERED POLLUTED WHEN ANY SINGLE SOURCE OF LARGER DISPERSED SOURCES MAKE WATER QUALITY UNSUITABLE FOR DESIRED USES. WATER POLLUTION IS CATEGORIZED AS EITHER POINT-SOURCE POLLUTION OR NONPOINT POLLUTION. POINT-SOURCE POLLUTION IS SINGLE SOURCE FROM A SPECIFIC LOCATION; CAN BE FROM DRAIN PIPES, DITCHES, OR SEWER LINES. MOST DEVELOPED COUNTRIES HAVE LAWS TO HELP CONTROL THESE SOURCES OF POLLUTION. NONPOINT POLLUTION IS DISPERSED SOURCE POLLUTION WITH SCATTERED AND DIFFUSE RELEASES THAT CANNOT BE EASILY TRACED. THE MAJORITY OF SURFACE WATER POLLUTION COMES FROM NONPOINT POLLUTION SOURCES.

73 LEADING SOURCES OF WATER POLLUTION NUMBER 1 AGRICULTURE THE LEADING CAUSE OF WATER POLLUTION. SURFACE WATER RUNOFF (NONPOINT SOURCES) CARRIES WITH IT ERODING SOIL SEDIMENTS, EXCESS FERTILIZERS, AND PESTICIDES INTO NEARBY WATERWAYS.

74 LEADING SOURCES OF WATER POLLUTION NUMBER 2 INDUSTRIAL CREATE LARGE AMOUNT OF INORGANIC AND ORGANIC WASTES THAT OFTEN MAKE THEIR WAY INTO OUR WATER SUPPLIES. COMMON INORGANIC POLLUTANTS INCLUDE ACIDS, HEAVY METALS, AND FERTILIZERS. INDUSTRIAL ORGANIC POLLUTANTS INCLUDE PCBS, MOTOR OIL, GASOLINE, VOLATILE ORGANIC COMPOUNDS (VOCS), ETC.

75 LEADING SOURCES OF WATER POLLUTION NUMBER 3 MINING EXPOSE LARGE AREAS OF THE EARTH S SURFACE TO EROSIVE FORCES SUCH AS WIND AND RAIN. THIS CREATES RUNOFF OF PRECIPITATION AND SEDIMENTS THAT CARRY WITH IT HARMFUL CHEMICALS SUCH AS SULFURIC ACID, ARSENIC, AND CYANIDE. EROSION CAN ALSO RELEASE HEAVY METALS FROM THE ROCK LAYERS, SUCH AS MERCURY.

76 INFECTIOUS DISEASE FROM INADEQUATE SANITATION HUMAN HEALTH IS AT RISK WHEN EXPOSED TO INFECTIOUS DISEASE FROM INADEQUATE SANITATION PRACTICES OF DRINKING WATER AS WELL AS LACK OF WATER FOR ADEQUATE HYGIENE. EACH YEAR, MILLIONS OF PEOPLE, MOSTLY CHILDREN, DIE FROM PREVENTABLE DISEASES LIKE DIARRHEA FROM UNCLEAN WATER USED FOR DRINKING AND HYGIENE.

77 INFECTIOUS DISEASE FROM INADEQUATE SANITATION ONE METHOD SCIENTISTS USE TO DETECT THE PRESENCE OF INFECTIOUS AGENTS IN WATER IS TO TEST FOR COLONIES OF FECAL COLIFORM. COLIFORM BACTERIA, SUCH AS E. COLI, THAT LIVE IN HUMAN AND ANIMAL INTESTINES, DO NOT ALWAYS CAUSE DISEASE BUT CAN INDICATE WHEN WATER HAS COME IN CONTACT WITH WASTE THAT COULD POTENTIALLY CARRY DISEASE-CAUSING BACTERIA.

78 EVERYONE, EVERYWHERE BY 2030

79 TED TALK: WOMEN AND WATER