Post on 18-Apr-2020
The Relationship Between Land Use And Phosphorus LoadingA Sampling of Forested and Agricultural Land Use Basins Within The Lamoille Valley
Alan Therrien and Jay Modry, Hazen Union School
HypothesisIf we test the phosphorus levels of the river at different sites with different land uses
then we will find that the phosphorus will be more abundant at the sites where there is
more agriculture and less forest in the drainage basins. We predict this because there
is phosphorus found in many things that are found in agricultural areas such as
fertilizer and manure. These types of things are not found in forested areas so the
phosphorus levels at the sites with the heavily forested drainage basins should be
much lower.
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Watershed Classification
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Watershed Classification
Site 1
Watershed Class 1 "Forested"
% Forested
% Ag
% Urban
%Other
Site 2
Watershed Class 1 "Forested"
% Forested
% Ag
% Urban
%Other
Site 3
Watershed Class 2 "Forest/Ag"
% Forested
% Ag
% Urban
%Other
Site 4
Watershed Class 2 "Forest/Ag"
% Forested
% Ag
% Urban
%Other
Site 5
Watershed Class 3 "Agriculture"
% Forested
% Ag
% Urban
%Other
Site 6
Watershed Class 3 "Agriculture"
% Forested
% Ag
% Urban
%Other
Upper Lamoille In Forested Area
Phosphate Being Applied On Agricultural LandManure on Agricultural Field Above Tributary
Methods To test our hypothesis we needed to take water samples from our designated sites, and
use the data that was collected by other schools at the other sites. We collected the
samples by using the designated Total Phosphorus bottles that were sent to us by the
EPSCOR project along with the other containers we were using to collect samples such
as Total Suspended Solids and Bacteria. We collected this data about twice a month
from the end of summer and into the fall until the river became too dangerous to collect
samples. After the samples were collected they were sent back to the lab where they
were tested and the results were then posted online. This is how we were able to use
data from not only our site, but those of others who were participating in the project.
In order to answer our question we needed drainage basins along the Lamoille River
that had different percentages of forested and agricultural land. This is where we used
the GIS software to produce a map with six different basins that could be separated into
three different classes, depending on their percent of forested area. Within each of
these three different classes we chose two different sites to calculate the phosphorus
levels.
After averaging the calculated phosphorus levels for a certain site in micrograms/liter, we
converted the data into milligrams/cubic meters. We then multiplied by the flow in cubic
meters/second, then seconds/minute, minutes/hour, and hours/day to get our final
calculations in mg/ day. However, since the drainage basins were not all the same size
we also divided by the acreage of the basin to so that we could more accurately
compare them.
Land Use Classification
Class 1 >90% Forested
Class 2 70%-90% Forested
Class 3 <70% Forested
ConclusionAfter comparing the average levels of phosphorus in ug/l and
mg/acre/day, we can conclude that there is a difference
between the drainage basins in the 3 different classes. From
those sites in Class 1 the levels of phosphorus are much lower
than the other 2 classes. Class 2 levels are in the middle and
Class 3 levels are the highest, just as we predicted they would
be. The different factors in the less forested/more agricultural
areas do seem to have an affect on the amount of phosphorus
that flows into the streams. We don’t want these higher levels
of phosphorus to flow into the Lamoille River and eventually
into Lake Champlain because the high levels are not natural,
and not healthy for the lake. When the phosphorus levels in a
lake like Lake Champlain get higher then normal, the growth of
the algae blooms dramatically increases. That’s why
phosphorus is commonly used in fertilizers, it can increase the
growth of plants. When these algae blooms grow, they take up
more oxygen from the water in the lake, which in turn can be
harmful to other organisms also living in the lake. The
excessive growth of the algae on the surface also blocks the
sunlight from penetrating the deeper water, making it almost
impossible for other organisms to live in. This process is called
eutrophication.
AcknowledgementsI would like to thank everyone involved with the EPSCOR Streams Project for all the materials
they provided us, the lab work, and the database. I would also like to give a special thanks to
Lexie Reiss Haselton, the GIS/Database Specialist for all of her help with mapping out the sites
and the drainage basins.
Lamoille Enters Lake Champlain After 85 Miles, Draining 706 Square Miles