Today’s Agenda: Lecture I

1. Today’s Agenda: Lecture I Environmental Science Journal Questions: Describe three characteristics of water. What is the water cycle? *1. Lecture: The Water Cycle 2. Homework: Read water related chapter in your textbook.

2. Nutrient Cycles: The Water (Hydrologic) Cycle By Dr. Woodward Environmental Science

3. Nutrient Cycles A. Nutrient cycles involve natural process that recycle nutrients in various chemical forms in a cyclic manner from the nonliving environment to living organisms and back to the nonliving environment again. B. There are three general types of nutrient cycles: 1. Hydrologic (Water) Cycle 2. Atmospheric Cycle 3. Sedimentary Cycle Environmental Science

4. The Hydrologic (Water) Cycle A. The water cycle collects, purifies and distributes the Earth’s fixed supply of water. 1. Evaporation (conversion of water into water vapor) 2. Transpiration (evaporation from leaves) 3. Condensation (conversion of water vapor into droplets of liquid water) 4. Precipitation (rain, sleet, hail, snow) 5. Infiltration (movement of water into soil) 6. Percolation (downward flow of water through soil and permeable rock formations to groundwater storage areas called aquifers) 7. Runoff (down-slope surface movement back to the sea to resume the cycle) Environmental Science

5. The Water Cycle Environmental Science

6. The Water Cycle Continued: B. The water cycle is powered by energy from the sun and by gravity. C. About 84% of the water vapor in the atmosphere comes from the oceans. D. Oceans cover about 71% of the Earth’s surface. E. On a global scale, the amount of water vapor entering the atmosphere is equal to the amount returning to the Earth’s surface as precipitation. Environmental Science

7. Human’s Influence on the Water Cycle A. We withdrawal large quantities of fresh water from streams, lakes, and underground sources for drinking potable water. B. Clearing vegetation from land for agriculture, mining, road and building construction. This increases runoff, accelerates soil erosion and landslides. C. We modify water quality, particularly by adding nutrients (such as phosphates) and other pollutants creating water pollution. Environmental Science

8. The Importance of Water A. Water covers 71% of Earth’s surfaces. • About 97.5% of this volume is the salt water of the oceans and seas. The major biological source of dissolved oxygen in the ocean comes from photosynthesis by phytoplankton. C. The remaining 2.5% is fresh water. 1. Fresh water is water with a salt content of less than .1% -This is the water upon which most terrestrial biota, ecosystems, and humans depend on. D. Earth’s organisms are made up of mostly water. E. A tree is about 60% water by weight. F. Most animals and humans are about 50-65% water. Environmental Science

9. The Composition of Water • Water is found in three physical states: 1. Ice (solid) at O degrees Celsius 2. Liquid water (liquid) 3. Water vapor (gas) B. Chemical formula: H20 1. A weak attraction known as hydrogen bonding tends to hold water together Environmental Science

10. Only 2.5% Fresh Water! • Of the 2.5% fresh water available, two-thirds of it is bound up in the polar ice caps and glaciers. • Thus, only .77% of all fresh water is found in lakes, wetlands, rivers, groundwater, biota, soil, and atmosphere. • Nevertheless, evaporation from the oceans combines with precipitation to re-supply that small percentage continually through the water cycle. • Thus, fresh water is a continually renewable resource. Environmental Science

11. Freshwater Ecosystems: Just 3% of all freshwater! Environmental Science

12. Fresh Water • A vital resource for all land ecosystems, modulating climate through evaporation. • The Water (Hydrologic) Cycle reviewed: (1) Water rising to the atmosphere via transpiration and evaporation and returning to land via condensation and precipitation. Environmental Science

13. The Power of Water • Irrigation makes it possible to grow 40% of the world’s food. • One-fifth of all electricity is generated through hydropower. • In the developing world: 1. Over 1 billion people still lack access to clean drinking water. 2. 2 ½ billion people do not have access to adequate sanitation services. 3. Over 3 million deaths each year are traced to waterborne diseases (mostly children under five). Environmental Science

14. Water Terminology • Hard water: Water that contains minerals, especially calcium or magnesium, that causes soap to precipitate, producing scum, curd, or scale in boilers. • Soft water: Water that is relatively free of minerals. • Turbid: Cloudy water due to particles present. • Brackish water: A mixture of fresh and salt water, typically where rivers enter the ocean. • Storm water: Water from precipitation that runs off of land surfaces in surges. • Salinity: The concentration of salt (Na+) in a substance. Environmental Science

15. Dedication to My Class during 7th Period Environmental Science Lecture II -Purchase an AP Prep Book for Environmental Science –Dedicate yourself to doing well! *1. Water Lecture continued…. 2. Population 7 billion…. That is a question… The world population is the total number of living humans on the planet Earth, currently estimated to be 6.96 billion by the United States Census Bureau as of July 1, 2011 3. Homework…

16. Arctic Sea Ice (September 16, 2011) Environmental Science The. Arctic Sea Ice has melted to near record levels Second lowest level recorded ever. It is more evidence of climate change. The ice could shrink even further. It’s having a huge impact on 20,000 desperate walruses who are hauling themselves onto land to look for food. Normally, something they would do normally and on Ice Flows

17. What do you think? Refer to the following qualities of water: • Acidity • Turbidity • Hardness • Dissolved Oxygen • Salinity • ___ Measured on the pH scale. • ___ Caused by suspended particulates. • ___ Decreased breakdown of organic wastes. • ___ Measured by the amount of Ca 2+ and Mg 2+ Environmental Science

18. Correct Answers: 1. Measured on the pH scale a. Acidity 2. Caused by suspended particulates b. Turbidity 3. Decreased by the breakdown of organic wastes d. Dissolved oxygen 4. Measured by the amount of Ca 2+ and Mg 2+ c. Hardness Environmental Science

19. Green vs. Blue Water • Green Water: Water in the soil and in organisms that eventually ends up as water vapor –the main source of water for natural ecosystems and rain-fed agriculture. • Blue Water: Renewable surface water runoff and groundwater recharge –the focus of management and the main source of water for human withdrawals. Environmental Science

20. Infiltration • As precipitation hits the ground, it may either soak into the ground (infiltration) or run off the surface (runoff, a blue water flow). • Runoff flows over the surface of the ground into streams and rivers, which make their way to the ocean or to inland sea. All the land area that contributes water to a particular stream or river is referred to as the watershed. Environmental Science

21. Groundwater A. Groundwater: Water that fills the cracks and pores in underground soil and rock layers. (gravitational water) B. The groundwater encounters an impervious layer of rock and dense clay, where it accumulates above this layer of stone. The upper surface water is referred to as the water table. C. As groundwater seeps laterally, searching for its lowest level, it seeps into an underground layer of rock or soil that holds water (an aquifer) D. Underground aquifers hold 99% of all liquid fresh water; the rest is in lakes, wetlands, and rivers. Environmental Science

22. well Soil Capillary Water Unsaturated Rock WaterTable Saturated Rock (Aquifer) Saturated Water Environmental Science

23. Sanitary well cap Good casing Sloping Ground Soil Grout seal Bedrock Water Table Groundwater “aquifer” Environmental Science

24. Groundwater Problems • Already, more than 2 billion people depend on groundwater supplies. • Groundwater depletion is considered the single biggest threat to irrigated agriculture. • Agriculture chemicals such as fertilizers and pesticides, animal wastes, and industrial chemicals readily enter the groundwater, making groundwater pollution a great threat. Environmental Science

25. Growing Trend: • Desalination is the desalting of seawater. • More than 13,600 desalination plants currently exist throughout the world. • These plants are very costly. • The alternative: Use less water! 1. The United States consumes an average of 106 gallons of water per person per day. Environmental Science

26. What do you think? • Of the following, which constitutes the greatest percent of domestic use of water in the United States? (a) Flushing toilets (b) Drinking (c) Cooking (d) Washing Dishes (e) Washing Clothes Environmental Science

27. Correct Answer Correct Answer: (a) Flushing Toilets Environmental Science

28. Freshwater Ecosystems Environmental Science

29. Freshwater Ecosystems: Just 3% of all freshwater! Environmental Science

30. A Few Freshwater Ecosystems • Standing waters • Lakes • Ponds • Reservoirs • Flowing waters • Rivers • Streams • Groundwater • Wetlands • Estuaries Environmental Science

31. Ponds: • Shallow holes where freshwater collects • Little wave action • Muddy bottom • Shallow enough to support rooted plants • Basically a small lake • But shallower • Same temperature from top to bottom • Greatly affected by local conditions and climate • Can freeze solid Environmental Science

32. Pond Succession: • Geologically created • Glacier • Sink hole • Seeds are “flown in” by birds • Plants start to grow throughout pond • Debris on bottom increases • Layers build up over 100’s of years • Pond gets shallower • Larger plants/trees are able to grow across whole pond • Is now a marsh • Marsh  Swamp (can dry out)  Forest/Grasslands Environmental Science

33. Lecture III Environmental Science Today’s Agenda: (1) What does desalination refer to? (2) What are two threats to ground water pollution? *Lecture III: Freshwater Sources Continued..

34. Lake/Reservoir Characteristics: • Freshwater • Too deep for rooted plants (except near shore) • Large • Wave formation • Lake Superior • 31,700 square miles, 1,300 ft deep • Stratified (i.e. - layered) • Layers caused by • Temperature • Light • Oxygen • Nutrients • Reservoirs are man-made lakes (generate power, flood control, create municipal water supplies) Environmental Science

35. Lake Stratification by light: • Littoral zone • Where sunlight can reach the bottom • Open Water • Epilimnion • Sun warmed upper layer • Affected by surface mixing from wind and temp fluctuations • Contains most of photosynthetic production • Hypolimnion • Cold, dark bottom layer Environmental Science

36. Stratification (layers) of a deep lake • Temperature also decreases with increasing depth • Summer Temps: Top (65-75ºF), Mid (45-65ºF), Deep (39-45ºF) Environmental Science

37. Environmental Science

38. Lakes also Classified by Trophic state • Productivity • Nutrient levels affect algae • Algae is green (Chlorophyll a) • Affects water clarity • Secchi disk test • Oligotrophic - little nutrition • Eutrophic - well nourished • Food chain • Algae- zooplankton-insects and fish - larger fish, animals • Algal Blooms • Nutrients too high • Block light to lower layers • Algae die and fall to bottom, decompose and Oxygen drops • Cultural Eutrophication/Dead zones Environmental Science

39. Secchi Disk • Used to measure water clarity. • Step 1: From a boat or dock, lower the secchi disk into the water until it disappears. • Step 2:Raise the secchi disk very slowly until you can see it again. • Step 3: Notice where the water’s surface intersects the marked line. • Step 4: Pull the secchi disk in, holding the line at this intersection point. • Step 5:Measure the distance from the disk to the point where the water intersected the line by counting the distance markings. • The resulting measurement is the depth of water clarity. Environmental Science

40. Oligotrophic versus Eutrophic Environmental Science

41. The role of phosphate • Phosphate is an ion composed of a phosphorus atom with four oxygen atoms attached. • Phosphate is an important plant nutrient. • In natural waters, it is frequently the limiting factor; therefore, additions of phosphate to natural water are often responsible for algal blooms and plant growth. Environmental Science

42. Environmental Science

43. Recent Algal Blooms at the Summer Olympics in China Environmental Science

44. China Environmental Science

45. China Environmental Science

46. Ocean Vocabulary: • Eutrophic = Characterized by nutrient-rich water supporting an abundant growth of algae or other aquatic plants at the surface. • Deep eutrophic water has little or no dissolved oxygen. • Eutrophic Zone: In aquatic systems, the layer or depth of water through which an adequate amount of light penetrates to support photosynthesis. • Two sources of eutrophication are: *(1) Phosphates (2) Nitrates Environmental Science

47. Environmental Science

48. Ocean Vocabulary Environmental Science The major biological source of dissolved oxygen in the ocean comes from photosynthesis by phytoplankton. Plankton: Any and all living things that are found freely suspended in the water and that are carried by currents, as opposed to being able to swim against currents. Plankton includes both plant (phytoplankton) and animal (zooplankton) forms.

49. Eutrophication Environmental Science

50. What do you think? • Which of the following will result in acceleratedeutrophication when introduced into streams, lakes, and bays? (a) Bacteria and viruses (b) Pesticides (c) Herbicides (d) Phosphates (e) Acid wastes and salts Environmental Science