Lake Morphometry and Field Techniques

Lake Morphometry and Field Techniques - Lake Morphometry...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Lake Morphometry and Introduction to Field Study of Lakes Lecture 2B Fall 2011 BIOL/EVPP 350 Freshwater Ecosystems Dr. Kim de Mutsert
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Morphometry Morphometry is the quantitative description of the shape and size of lakes - Shore length - Area - Depth - Volume It defines a lake’s physical dimensions and involves the quantification and measurement of lake basin shape These dimensions influence the lake’s water quality, productivity levels and habitat quality
Background image of page 2
Shoreline Development Index A ratio of the measured shore length to the minimum length possible of a lake with the same area = the circumference of a circle with the same area: SDI = L/(2√Aπ) L = shoreline length A = lake area One measure for habitat complexity: A higher SDI provides better habitat for fish
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Areal characteristics: % littoral area The littoral (shallow near shore) zone is the portion of a lake where sufficient light can penetrate to the lake bottom. It is also sometimes defined as that portion of the lake that is less than 15 feet in depth. The littoral zone is where the majority of the aquatic plants are found and is a primary area used by young fish.
Background image of page 4
Watershed The area of landscape that contributes to the water supply of a lake Used in areal characteristic: The ratio of watershed area to lake area A w /A o Used as one indication of potential nutrient loading
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Working with a bathymetric map A lake map with contour lines is a bathymetric map The lines are called isobaths (connect same depth) Many lakes have already been mapped and a good map will contain the following: name, county, and geographic location of the water body an outline of the shoreline drawn to a known scale depth contours drawn to a known interval geographic orientation (which way is north?) date of map and data collectors
Background image of page 6
Areal characteristics meters feet Fetch Max width Max length % (ratio of meters/feet) meters feet meters feet hectares (ha) acres (ac) meters feet units elevation Shoreline development index (SDI) Shoreline length (L) Littoral Area maximum depth (z max ) surface area (A o ) characteristic A surface map allows determination of these areal characteristics
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Areal characteristics Maximum length (fetch) Maximum width Z max Several areal characteristics and measurements can be taken directly off the bathymetric map
Background image of page 8
Surface area: grid method You’ll need: Bathymetric map Grid paper Method: Count up the number of squares that fall within the shoreline of the lake Use the map scale to determine area represented by each square scale Area = # squares counted X area of one square
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Volumetric characteristics Bathymetry also allows determination of several volumetric characteristics years Hydraulic residence time (HRT) Graph (depth vs volume) Volumetric curve Graph (depth vs area) Hypsographic curve meters feet Mean depth (z mean or z) Cubic meters acre feet Stratum volume Cubic meters acre feet Volume (V) units characteristic
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/23/2012 for the course BIOL/EVPP 350 taught by Professor Kimdemutsert during the Fall '11 term at George Mason.

Page1 / 50

Lake Morphometry and Field Techniques - Lake Morphometry...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online