2. Streams
• A body of water with a current, and is smaller
than a river
• When joined, they form a bigger body of water
either flowing or nonflowing water ecosystem.
▫ Lakes
▫ Ponds
▫ Inland wetlands
– Rivers
3. Rivers
• A body of water with a current and is larger than
streams
• The volume of water it carries is larger than the
volume of water streams carry.
5. Watershed
• A watershed is the area of land where all of the
water that is under it or drains off of it goes into
the same place.
6.
7. Watershed
• Closed watershed
▫ empties into an inland body of water
• Open watershed
▫ empties to the ocean
• Multiple open watershed
▫ empties into the ocean through more than one
mouth
9. Tributary
• A tributary is a stream that flows into a larger
stream or other bodies of water.
• A contributory stream, or a stream which does
not reach the sea but joins another river.
13. Upper Course
• Where the river begins
• Many smaller streams join
up to form larger streams
• Several streams join up to
form a river
• Narrow and v-shaped river
channel
• Steep gradient
14. Middle Course
• River starts to meander
• More tributaries
joining the river
• Wider river channel
than upper course
• Gentler gradient as
compared to upper
course
15. Lower Course
• Meanders are common
• Distributaries distribute
water away from the river
to the sea
• Wider river channel than
middle course
• High volume of water
• Gentle gradient
16. Three main types of rivers
• Youthful River - A youthful river has a steep
gradient and very few tributaries. A youthful river is
bound to flow quickly and swiftly.
Mature River - A mature river is less steep and
flows slowly compared to the youthful river. There
are many tributaries that feed a mature river. The
sediment deposit is also less.
Old River - An old river has a low gradient and is
depended on flood plains is known as old river.
20. Where are rivers located?
Rivers are found anywhere in the world except in
antarctica.
21. Top 3 longest rivers in the world
• The longest river in the world is the Nile River
(4,157 miles long); it is located in northeastern
Africa, and flows into the Mediterranean Sea.
22. • The second-longest river is the Amazon River
(3,915 miles long); it is located in northeastern
South America, and flows into the Atlantic
Ocean.
23. • The third-longest river is the Chang (Yangtse)
River (3,434 miles long); it flows across south-
central China into the East China Sea.
24.
25. 12th order stream, the
highest rank possible in the
stream order system.
27. Three main types of streams:
• Ephemeral streams
▫ regularly exist for short periods of time, usually
during a rainy period.
• Intermittent streams
▫ flow at different times of the year, or seasonally,
when there is enough water from either rainfall,
springs, or other surface sources.
• Perennial streams
▫ streams that flow year-round.
28. The tributaries (streams) are identified by
their stream order, denoted by its position
in the system.
Stream Order Characteristics
First Order not connected to any other tributaries
Second Order
connected to one other
stream/tributary
Third Order joining of two second order streams
34. ABIOTIC FACTORS
• Precipitation
▫ Important in formation of streams and rivers.
▫ Amount of precipitation in an area determines
which type of stream should be present at that
area.
• Current
▫ It will determine the substrate at the bottom of the
stream or river.
35. ABIOTIC FACTORS
• Landscape
▫ The direction of stream flow is dependent upon
the slope and obstructions of the landscape.
• Temperature
▫ Affects the organisms living in streams and rivers.
▫ Affects growth and development of organisms.
▫ Reproduction
Different organisms reproduce at different
temperatures
36. ABIOTIC FACTORS • Trout will not
reproduce
below 3 degrees
and ideally
between 5 and
16 degrees.
45. • Extremely flattened
and broad bodies, flat
limbs
▫ Allow the current to
flow over the bodies
of some larval forms
Blackfly larvae
46. • Snails and planarians
▫ Attached themselves to sticky
undersurfaces allowing them to cling
tightly and move about on stones and
rubble in the current.
47. • Smallmouth bass
▫ Strong lateral muscles
(needed in the fast
current for
compressed
bodies)that enable
them to move through
beds of aquatic
vegetation
48. Four major groups of inhabitants
(according to feeding habits)
• Shredders
▫ Feed on coarse
particulate organic
matter (CPOM)
CPOM – mostly leaves
that fall into the
stream and are
softened by water and
colonized by bacteria
and fungi.
Casemaker caddisfly
49. • Filtering and gathering collectors
▫ Feed on the fine particulate organic matter (FPOM)
FPOM – leaves that are broken down by the
shredders, partially decomposed by microbes, and
invertebrate feces that drift downstream and settle on
the stream bottom.
Freshwater mussels
50. • Grazers
▫ Another group that feed on the algal coating of
stones and rubble
Water penny
52. Human impact
• Draining of rivers and streams
The now dry Colorado River delta
branches into the Baja/Sonoran
desert just five miles north of the
Sea of Cortez, Mexico. Photo by
Peter McBride
53. • Water diversion and regulation of flows
due to dams.
▫ Principal reasons why dams are built:
Flood protection
Recreation
Industrial purposes
Electricity
Water supply
Political reason
55. Impacts of dams on streams
• traps the suspended and dissolved load,
starving the area downstream of sediment and
nutrients
• a barrier to any aquatic life going up or down
stream, which can prevent aquatic life from
mating and reduce the diversity of wildlife
upstream
56.
57. • Flood Control:
▫ Channelization: Straightening out the meanders of a
stream to for a straight line, or smoothing out the
natural levee by replacing it with concrete flood walls.
▫ Artificial Levees: Artificially raising the height of a
natural levee.
Channelization Artificial leevee
58. • Urbanization
▫ When houses or businesses are built in a floodplain,
they get flooded.
▫ Increases runoff into streams, which further
increases the chances of flooding
