Surface (Running) Water and Groundwater Chapter 9 &10
“Whiskey’s for drinking, water’s for fighting over.”Mark Twain
If a women only had to carry water for one hour a day then she could earn an additional $100 US each year.
Worldwide the average girl walks a minimum of 6 km (3.5 miles) and carrying 20 liters (5.3gal) of water (40lbs) several times a day. During the dry season in Viet Nam the village girls can not attend school because they have to walk 30km each day to fetch water
Among adolescent girls, school attendance drops dramatically when there are no clean and safe latrines in the school.
Global Water Ocean (Salty) 97.2 % Fresh Water 2.8 % Ice 2.15% Liquid 0.65% Groundwater 0.62% Lakes 0.009% Soil Moisture 0.005% Streams and Rivers 0.001% Atmosphere 0.0001%
Why Not Use Sea Water? Desalination now provides 1% of world drinking water Distillation (Energy intensive) Passive distillation (Slow, inefficient) Reverse Osmosis (Filters delicate, prone to clogging and contamination) Towing Antarctic Icebergs (Not done yet, but the numbers are promising)
Objectives Chapter 9 Objective 1:Describe the distribution of H2O within the Hydrosphere and the movement of H2O through the hydrologic cycle. Objective 2: Describe the process of stream flow and the factors influencing stream erosion, transportation, and deposition. Objective 3: Give examples illustrating the connection between landscape features and runoff including channels, stream valleys, flooding events, and drainage patterns.
Infiltration Runoff, 40 Groundwater Flow Source: http://www.coloradocollege.edu/dept/ev/courses/EV211WWW/hydrological%20cycle.jpg The Hydrologic Cycle • Hydrologic Cycle: circulation of Earth’s water supply among the oceans, the atmosphere and the continents • Powered by Sun’s energy • Water is transported by: • Evaporation – liquid water converts to gas and rises into atmosphere from land or oceans • Precipitation – gaseous water in atmosphere condenses back into liquid and drops onto land or oceans • Infiltration – water from precipitation soaks into the ground • Runoff – water from precipitation flows over ground surface • Transpiration – water absorbed by plants is released into the atmosphere
E A B C D • Use the diagram and select the appropriate letter for each term (a b c d e): • 1. Source of heat energy • 2. Infiltration • 3. Precipitation • 4. Runoff • 5. Evaporation
True or False 6.Since the water cycle is balanced, the average annual precipitation worldwide must equal the quantity of water evaporated. 7. Water is constantly moving among the oceans, atmosphere, solid Earth, and the biosphere. Multiple Choice 8. The unending circulation of Earth's water supply is called: a. system b. hydrosphere c. renewable resource d. hydrologic cycle e. evaporation
9. The hydrologic cycle is primarily powered by: a. gravity b. heat c. the sun d. pressure e. all of the above 10. When the ground cannot absorb the rainfall, and it does not evaporate, the water flows over the surface into lakes and rivers as: a. glaciers b. infiltration c. Runoff d. groundwater e. condensation
Running Water • Importance: • Energy • Travel • Irrigation • Fertile floodplains • Shaping of landscape (via erosion) • Stream: channel of flowing water of any size • River – larger streams • Tributaries or brooks – smaller streams • Streams flow because of gravity • Streams are supplied by runoff and infiltrating groundwater. • Runoff and groundwater come from precipitation. • Drainage basin: land area that contributes water to a stream. • Divide: imaginary line separating drainage basins.
The drainage basin of one stream is separated from the drainage basin of another stream by an imaginary line called a: a. Overland b. Separation c. Water Gap d. Drainage pattern e. Divide • We depend on running water for: a. Energy b. transportation c. irrigation d. Most of our drinking supplies e. a, b and c f. All of the above
Stream Velocity • Stream Velocity: distance water travels in given time • Measured at gauging stations • Stream velocity determines erosional capability • Three factors affect velocity: • Gradient (slope) – expressed as the vertical drop of a stream over a fixed distance. High gradient = high velocity. • Channel characteristics (shape, size and roughness) – more on this in next slide. • Discharge (volume of water flowing per unit time) – High discharge = high velocity. Discharge also affects channel characteristics.
13. The dominant process in the upstream area of a river system is: a. gradient b. deposition c. erosion d. upstream e. transportation 14. The volume of water flowing past a certain point (measured in cubic feet per second) is known as: a. competence b. laminar c. discharge d. turbulent e. capacity
Stream Channel Characteristics • Channel shape (cross-sectional) affects velocity. • Wide, shallow channel = slower (a lot of friction with streambed). • Semicircular channel = faster (least amount of friction). • Channel size: larger = faster. • Channel roughness: smoother = faster. 15. Which stream below is faster? A B
http://www.geocities.com/geomwl/davis2.gif Stream Valleys • Young streams demonstrate V-shaped valleys. • Shape results from downcutting. • Rapids and waterfalls are common. • Older streams begin to erode to the side more than downward, and create a floodplain. • River is confined to channel except during flooding, when it deposits sediments. • Meanders (large curves in river) and oxbow lakes are common.
Geologic Work of Streams – Transportation of Sediment • Running water is the single most important factor in shaping the Earth’s land surface. • Water carries sediments in 3 ways: • In solution (dissolved load) – mostly transported by groundwater • In suspension (suspended load) – most materials carried by streams are suspended loads • Along bottom of channel (bed load) – moves only intermittently
Geologic Work of Streams – Deposition of Sediment • Streams deposit suspended sediment when they slow down. • Recall from unit on rocks: fast streams can carry larger particles, while slow streams can only carry smaller particles. • Sorting: particles of similar size are deposited together • Alluvium: material deposited by a stream • Delta: deposits near the mouth of a river into a lake or ocean • Alluvial fan: similar to deltas, but on land – stream deposits sediment where it empties into a plain
16. Most large rivers carry the largest part of their load: a. as bed load b. in solution c. near their head d. during the dry season e. in suspension
Objectives Chapter 10 • Concept 4: Discuss the occurrence and movement of groundwater. • Concept 5: Explain unique features and environmental concerns associated with groundwater and the use of groundwater as a nonrenewable resource including: subsidence, contamination, and sinkholes. The story of groundwater video.
How Much Water does it take to produce ? • A serving of almonds? • An orange? • A serving of French fries? • A head of lettuce? • A gallon of milk? • A serving of rice? • A tomato? • A watermelon? • An egg? • A loaf of bread? • A car? • A hamburger? Answer Choices: 3 gal 6 gal 12 gal 14 gal 35 gal 65 gal 100 gal 120 gal 150 gal 1300 gal 39,000 gal
Answers • A serving of almonds? • An orange? • A serving of French fries? • A head of lettuce? • A gallon of milk? • A serving of rice? • A tomato? • A watermelon? • An egg? • A loaf of bread? • A car? • A hamburger? 12 gallons 14 gallons 6 gallons 6 gallons 65 gallons 35 gallons 3 gallons 100 gallons 120 gallons 150 gallons 39,000 gallons 1300 gallons
Almond Blossom Almond Trees in Southern California Almonds are drupes not nuts. Drupes are stone fruits with a fleshy outer covering and a hard seed center. Like olives, nectarines, peaches, pistachios, mangos, dates, coconuts, plums and cherries.
How much do we depend on Groundwater? • 22% of all freshwater withdrawals • 37% of agricultural use (mostly for irrigation) • 37% of the public water supply withdrawals • 51% of all drinking water for the total population • 99% of drinking water for the rural population
Groundwater • Groundwater: water that occupies pore spaces in sediment and rock in a zone beneath the Earth’s surface • Largest reservoir of fresh water available • Produces caves and sinkholes • Zone of Saturation: region where all the open spaces in sediment and rock are completely filled with water • Water Table: upper limit of the zone of saturation • Zone of Aeration: region above the water table where spaces are not completely filled
Groundwater Animation Watch animation
Well-sorted = high porosity Poorly-sorted = low porosity Groundwater Storage • Amount of water that can be stored depends on the porosity (the volume of open spaces) of a material. • Well sorted alluvial deposits have high porosity. • Poorly sorted alluvial deposits have low porosity – the small particles take up the spaces between the large.
Groundwater Movement • Movement of groundwater depends on the permeability (ability to transmit fluid through interconnected pores). • Fine texture = low permeability, slow movement • Coarse texture = high permeability, fast movement http://www.dmtcalaska.org/exploration/ISU/unit5/u5lesson1.html
Groundwater Movement • Aquitards: regions of materials with very small pore spaces (like clay) that hinder groundwater movement • Aquifers: regions of materials with large pore spaces (like sand) that are highly permeable
Springs • Springs occur when the ground surface is below the water table – groundwater then flows on the surface. • Springs often occur where an aquiclude blocks the downward movement of groundwater. • Example: Thousand Springs in Idaho
Wells • Wells are drilled openings into the zone of saturation. • Important freshwater source – 65% of wellwater is used for irrigation. • Drawdown: lowering of the water table as water is taken from a well. • Drawdown creates a cone of depression around the well (a local depression of the water table). • Not noticeable around domestic wells. • Problematic around industrial or irrigation wells – nearby shallow wells can dry up. http://www.epa.state.il.us/water/groundwater/wellhead-protection.html
Artesian Wells • Artesian Well: water rises above the level where it was tapped. • Can only occur when there is/are • An inclined aquifer where the higher side is exposed at the surface to receive water • Confining layers both above and below the aquifer keep it from moving anywhere except into the well. http://commons.wikimedia.org/wiki/File:Artesian_Well.png
Environmental Problems with Groundwater • Overuse can threaten supply. • Land subsidence: Groundwater removal can cause ground to sink (example: San Joaquin Valley dropped almost 9 meters between 1925 and 1975). • Groundwater contamination from: • Sewage • Other sources http://www.aegweb.org/images/Geologic%20Hazards/subsidence_Poland.jpg
Hot Springs and Geysers • Hot springs result from water that circulates deep below the surface and gets warmer (6-9 °C or 10-15 °F) than the average local air temperature. • Source of heat: cooling igneous rock • Geysers are intermittent hot springs or fountains that eject columns of water periodically. • Occur where extensive underground chambers exist within hot igneous rock – allows pressure to build up. • Example: Old Faithful in Yellowstone (erupts about every hour)
Geothermal Energy • Produced by tapping naturally occurring steam and hot water below the surface. • First commercial geothermal power plant in the U.S.: The Geysers, north of San Francisco • At peak, produced about 1800 MW (enough energy for San Francisco and Oakland) • Electricity production then started to decline as the source of hot water and steam were diminished. • This is not necessarily a renewable resource, and can’t provide a large percentage of the world’s power needs.