Title: Surface Water
1WATER
2Properties of 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
3Properties of Water
Cohesion, Adhesion and Surface Tension
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
4Properties of Water
Capillary Action
Because water has both adhesive and cohesive
properties, capillary action is present.
Capillary Action waters adhesive property is
the cause of capillary action. Water is
attracted to some other material and then through
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
5Properties of Water
In order to raise the temperature of water, the
average molecular speed has to increase. It
takes much 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.
High Heat Capacity
6Properties of Water
Density
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 rebonding space is
always changing
7Properties of Water
So, can you name all of the properties of water?
Adhesion Cohesion Capillary action High
surface tension Holds heat to regulate
temperature (High heat capacity) Less dense as a
solid than a liquid
8The ocean moderates coastal temperatures
- Water has high heat capacity, so it can absorb
(or release) large quantities of heat without
changing temperature - Moderates coastal temperatures
Figure 5-6
9Salinity
- Salinity total amount of solid material
dissolved in water - Can be determined by measuring water conductivity
- Typically expressed in parts per thousand ()
Figure 5-15
10Constituents of ocean salinity
- Average seawater salinity 35
- Main constituents of ocean salinity
- Chloride (Cl)
- Sodium (Na)
- Sulfate (SO42)
- Magnesium (Mg2)
Figure 5-13
11Salinity variations
Location/type Salinity
Normal open ocean 33-38
Baltic Sea 10 (brackish)
Red Sea 42 (hypersaline)
Great Salt Lake 280
Dead Sea 330
Tap water 0.8 or less
Premium bottled water 0.3
12Processes affecting seawater salinity
- Processes that decrease seawater salinity
- Precipitation
- Runoff
- Icebergs melting
- Sea ice melting
- Processes that increase seawater salinity
- Sea ice forming
- Evaporation
13Surface salinity variation
- Pattern of surface salinity
- Lowest in high latitudes
- Highest in the tropics
- Dips at the Equator
- Surface processes help explain pattern
Figure 5-20
14Surface salinity variation
- High latitudes have low surface salinity
- High precipitation and runoff
- Low evaporation
- Tropics have high surface salinity
- High evaporation
- Low precipitation
- Equator has a dip in surface salinity
- High precipitation partially offsets high
evaporation
15Seawater density
- Factors affecting seawater density
- Temperature ?, Density ? (inverse relationship)
- Salinity ?, Density ?
- Pressure ?, Density ?
- Temperature has the greatest influence on surface
seawater density
16Water, Water Everywhere
17All freshwater comes from two sources
- Water that seeps below ground
- Some is taken up and used by plants
- Large amounts found in underground rock
formations called aquifers
- Lakes, ponds, rivers, and streamsALL water above
ground - Most urban areas rely on surface water
- Supply resources and allow for travel/trade
18Surface water movement Water Cycle
- Earths water supply is constantly recycled
19Surface Water Movement
- 1) Runoff
- Water flowing down slope along Earths surface or
seep into the ground - Run off speed determined by slope of the hill
- Ends up in a stream or lake, evaporate, or
accumulate into puddles
20Movement
- Seep into ground
- Ground must have large enough pores loose soil
- Evaporate
21Fate of water Run off or Seep
- Certain characteristics will determine whether
not water will either seep into or become runoff - 1) Vegetation
- Vegetation allows for loose soil
- Loose soil allows water to enter ground
- Gardeners do not pack their soil
22Fate of water
- 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
23Fate of Water
- 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
24Fate of Water
- 4) Slopes
- Steep allows for high runoff little absorption
- Little low runoff and high absorption
25Formation of Stream systems
- 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 again each time with rain
- Channel can become a stream
26- Water sheds
- drainage basin
- Land where all water drains into
- Divide
- High land area that separates watersheds
27Mississippi Watershed
28Stream Load
- All the materials that the stream carries
- Solution
- Material that has been dissolved
- Depends on area where the steam runs through
- Erosion of rocks and dirt
29Stream Load
- Suspension
- Small particles held up by the turbulence of
stream - Clay, silt, 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
30Stream Velocity Carrying Capacity
- Discharge width x depth x velocity (m) (m)
(m/s) - As discharge increases so does carrying capacity
31Floods
- Water fills over the sides of a stream banks
- Floodplain broad flat area of land that extends
out from streams for excess flooding
32Freshwater Ecosystems
33Characteristics of a Freshwater Ecosystem
- 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
34Lakes and Ponds
35Rivers
- START in mountainous regions
- Cold
- Shallow beds
- Highly oxygenated
- A rivers characteristics changes with geography,
climate, and the runoff from nearby developments
36Wetlands
- 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)
37Freshwater Animal Adaptations
38Freshwater Plant Adaptations