I. Morphology of Lakes
A. Bathymetric
maps
contour lines = isobaths (iso-equal; bathy-depth)
surveying
and sonar
uses
B. Morphometry
Size parameters
1. Maximum depth = zm
2. Maximum length = l
3. Maximum width = b
at right angles to the maximum length line
4. Area
A0 - surface area
Az - area of contour at depth z
5. Volume
V = volume of the whole lake
Vz = volume below depth z
Shape parameters
6. Mean depth
7. Relative depth
ratio of maximum depth (z) to the mean diameter of the lake at the
surface,
expressed as a percentage
8. Shoreline development.
L = length of shore line
DL
= shoreline development
Other
useful morphometric tools
9. Hypsographic curve
area at each depth – m2 or %
can use to calculate the volume
10. Depth-Volume curve
volume at each depth – m3 or %
sediment water interactions
II. Lake and Stream Zonation
-- See page 132 of Wetzel
A. Lakes
1. Epilittoral -
2. Supralittoral
-
3. Littoral -
extends
from the seasonal high water level down to where the vegetation doesn't
grow due to a lack of light
eulittoral
upper littoral
middle littoral
lower littoral
4. Littoral-Profundal
- no higher plants
(can be algae)
5. Profundal -
sediment
free of vegetation; low light
6. Pelagic - open
water
a. trophogenic (euphotic) - enough light for production >
respiration
b. tropholytic - darker – respiration > production
B. Streams
1. Eucrenon - the
origin of the stream
2. Hypocrenon
3. Rithron - stony
stream zone
4. Potamon - lower
energy part of the stream - river
5. Riparian zone
5. Drainage classification
stream orders
C. Biological groups associated with zones (lakes only)
1. Pelagic
a. Seston - all particulate matter in the open water
(1) bioseston -- the living component
(2) tripton -- non living seston = detritus
b. Nekton -
can swim against currents
c. Plankton - movement influenced by turbulence
(1) euplankton - spend whole
life cycle in open water
(a) bacterioplankton
(b) phytoplankton
(c) zooplankton
(2) meroplankton - periodically enter the plankton, but can't
spend
their whole life cycle there
(3) pseudoplankton - organisms that don't really live in
pelagic,
but are swept there accidentally
2. Benthos
- organisms that live on the sediment water interface
a. Phytobenthos - 'macrophytes' higher plants; algae
b. Zoobenthos
3. Other
a. Pleuston - at the air-water interface
b. Neuston - microscopic pleuston
c. Periphyton - plants (and bacteria) that live on the
substrates
(1) epiphytic
(2) epipelic
(3) epilithic
(4) epipsammic
d. Psammon - interstitial fauna -- they live between sediment
grains
Interested
in
Book:
Håkanson, L.
2004. Lakes: Form
and Function. The
Articles:
Fee, E.J. 1979. A relation between
Hondzo, M. and H.G. Stefan. 2006. Dependence
of water
quality and fish habitat on
Rasmussen, J.B., L. Godbout, and M.
Schallenberg. 1989.
The humic content of lake water and its relationship to watershed and
Sterner, R.W. 1990.
Return to Limnology Lecture homepage