WATER CYCLE WEBQUEST
Water
PROPERTIES OF WATER
-UNIVERSAL SOLVENT
SURFACE WATER
-UNIVERSAL SOLVENT
- WATER IS THE SOLVENT OF LIFE!
- Solute: substance dissolved in a solvent to form a solution
- Solvent- fluid that dissolves solutes
- Example: ice Tea- water is the solvent and tea and sugar the solutes
- PROPERTIES OF WATER
- cohesion= water attracted to other water molecules because of polar properties
- adhesion= water attracted to other materials
- surface tension=water is pulled together creating the smallest surface area possible
- because water has both adhesive and cohesive properties, capillary action is present
- Capillary Action= water's adhesive property is the cause of capillary action. Water is attracted to some other material and then though cohesion, other water molecules move too as a result of the original adhesion
- Ex: think water in a straw
- Ex: water moves through trees this way
- in order to raise the temperature of water, the average molecular speed has to increase
- it takes more energy to raise the temperature of water compared to other solvents because hydrogen bonds hold the water molecules together!
- Water has a high heat capacity
- "The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius."
- water is less dense as a solid! This is because the hydrogen bonds are stable in ice-- each molecule of water is bound to four of its neighbors.
- solid- water molecules are bonded together-space between fixed
- liquid- water molecules are constantly bonding and rebounding-space is always changing
- adhesion
- cohesion
- capillary action
- high surface tension
- high heat capacity
- Density
- universal solvent
- water has high heat capacity
- Salinity = total amount of solid material dissolved in water
- Can be determined by measuring water conductivity
- Typically expressed in parts per thousand (‰)
- Average seawater salinity = 35‰
- Main constituents of ocean salinity:
- Chloride (Cl–)
- Sodium (Na+)
- Sulfate (SO42–)
- Magnesium (Mg2+)
- Processes that decrease seawater salinity:
- Precipitation
- Runoff
- Icebergs melting
- Sea ice melting
- Processes that increase seawater salinity:
- Sea ice forming
- Evaporation
- pattern of surface salinity:
- lowest in high latitudes
- highest in tropics
- dips at equator
- surface processes help explain pattern
- high latitudes have low surface saliniity
- high precipitation and runoff
- low evaporation
- tropics have high surface salinity
- high evaporation
- low precipiation
- equator has a dip in surface salinity
- high precipitation partially offsets high evaporation
SURFACE WATER
- lakes, ponds, rivers, and streams... all water above ground
- Most urban areas rely on surface water
- Supply resources and allow for travel/trade
- water that seeps below ground
- some is taken up and used by plants
- large amounts found in underground rock formations called aquifers.
- Runoff
- water flowing down slope along Earth's surface or seep into the ground
- run off speed determined by slope of hill
- ends up in a stream or lake, evaporate, or accumulate into puddles
- certain characteristics will determine whether not water will either seep into or become runoff
- 1) Vegetation
- allows for loose soil
- loose soil allows water to enter ground
- gardeners do not pack their soil
- 2) Rate of precipitation
- Heavy:
- soil clumps together closing pores
- fills up ground to quickly and water becomes runoff
- Light:
- allows water to gently slide through
- less erosion
- Heavy:
- 3) Soil Composition
- effects the waters holding capacity
- decayed organic matter (humus)
- creates the pores in soil- increases retain ability
- Minerals
- clay- fine mineral which clump together
- few spaces
- Sand- large pores
- clay- fine mineral which clump together
- 4) Slopes
- steep: allows for high runoff & little absorption
- little: low runoff and high absorption
- runoff
- surface water flows in thin sheets and eventually collects in small channels
- runoff increases, channels widen and become deeper and longer
- Channels fill up each time with rain
- Channel can become a stream
- water sheds:
- drainage basin
- land where all water drains into
- Divide
- high land area that separates watersheds
- all the materials that the stream carries
- Solution
- material that has been dissolved
- depends on are where the stream runs through
- erosion of rocks and dirt
- Suspension
- smalll particles held up by the turbulence of stream
- Clay, silt, and sand
- Depends on volume and velocity of water
- Bed Load
- turbulence of water pushes heavy things
- pebbles and cobbles
- larger velocity- large objects
- B/c of abrasion, rocks are smooth
- discharge= width times depth times velocity
- As discharge increases so does carrying capacity
- water fills over the sides of a stream banks
- Floodplain: broad flat are of land that extends out from streams for excess flooding
- slow moving waters
- low dissolved salt
- plant and animal life depends on depth of water, rate of flow, and amounts of nutrients, sunlight, and oxygen
- Include lakes, ponds, rivers, and wetlands
- start in mountaininous regions
- cold
- shallow beds
- highly oxygenated
- a rivers characteristics changes with geography, climate, and the runoff from nearby developments
- covered in water at least part of the year
- trap and fix carbon
- control flooding and absorb extra water when other bodies overflow
- Produce commercial products like seafood and berries (bogs)
Watershed and river basin Activity
groundwater notes
Distribution and movement of water underground
- much of the water in soil deeps downward untill it reaches the zone of saturation
- The zone of saturation is the area where water fills all of the open spaces in sediment and rock
- groundwater is the water within this zone
- the water table is the up-pest level of the saturation zone of groundwater
- Movement
- groundwater moves by twisting and turning through interconnected small openings
- the groundwater moves more slowly then the pore spaces are smaller
- Porosity
- the % of pore spaces
- determines how much groundwater can be stored
- Permeability
- ability to transmit water through connected pore spaces
- Aquifers are permeable rock layers or sediments that transmit groundwater freely
- Springs
- a spring forms whenever the water table intersects the ground surface
- Hot Springs
- water is 6-9 degree C warmer than the mean air temperature of the locality
- Water is heated by cooling of igneous rock
- Geysers
- intermittent hot springs
- water turns to steam and erupts
- Wells
- a well is a hole bored into the zone of saturation
- An artesian well is any formation in which groundwater rises on its own under pressure
- Pumping can cause a drawdown (lowering) of the water table
- Pumping can form a cone of depression in the water table
- a well is a hole bored into the zone of saturation
- overuse and contamination threatens groundwater supplies in some areas
- treating it as a nonrenewable resource
- Land subsidence caused by its withdrawal
- Contamination
- Caverns
- a cavern is a naturally formed underground chamber
- Erosion forms most caverns at or below the water table in the zone of saturation
- Tavertine is a form of limestone that is deposited by hot springs or as a cave deposit
- characteristics of features found within caverns
- formed in the zone of aeration
- composed of drip stone
- formed from calcite deposited as dripping water evaporates
- Common features include stalactites (hanging from the ceiling) and stalagmites (growing upward from the floor)
- Kart Topography
- formed by dissolving rock at, or near, Earths surface
- Common features
- sinkholes- surface depressions
- sinkholes form when bedrock dissolves and caverns collapse
- sinkholes- surface depressions
- area lacks good surface drainage
WATER QUALITY
HOW DO SCIENTISTS MEASURE WATER QUALITY?
- water samples, aerial photography, and aquatic life forms
- The health of a water body can be determined by analyzing physical, chemical, and biological factors
- dissolved oxygen (DO)
- how much oxygen is available for organisms to breather
- What photosynthetic organisms are mammals, pesticides, oils, etc or using oxygen
- pH
- measure of chemicals dissolved in the water
- Nutrients
- NPK
- Too many can stimulate algal growth to eutrophication
- Toxins
- metals, pesticides, oils, etc
- temperature
- dictates what life forms can survive
- the amount of direct sunlight
- warm water contains less DO than cold water
- Amount and speed of water
- Substrate on bottom
- large sediments stir up more water
- Turbidity
- how much suspended particles
- pathogens
- Bio indicators