Figure 6: Surface flow
rates for the esker mire complex.
Highest flow being on the sides of the esker, where the highest slope
angles occur. Slowest rates occur on
the peatland where it is extremely flat comparatively to the esker.
Rates of
Surface Flow
Surface Water Modeling of the Esker Mire Complex at Massawepie Boy Scout
Camp, Gale, NY
John
Rupp
Go into 3D analyst and go
down to convert raster to tin and create tin from the hillshade.
In Arc Toolbox go to the
surface hydrology tools and run tools such as flow direction.
In Arc Map start editing
and create hard break lines for the lakes that border the mire.
Analyze images created to
figure out surface water flow tendencies for the peatland.
Open Arc Scene and open
the tin of Massawepie and drape the aerial photo of Massawepie over the tin.
Fly towards the peatland
and note the missing section of the esker.
This has possibly been eroded into the peatland before peat has begun
growth.
Massawepie Mire is an ombrotrophic bog that is bounded
by an esker in Gale, NY. The surface of
the peatland is flat with a slight rise towards the center of the
peatland. The infrared aerial photo
shows the changes in vegetation very well.
There are three sections to the peatland all consisting of different
types of vegetation which is due to different acidities of water in these
parts of the peatland. Using GIS the
peatland surface water flow was able to be determined. The water flow off of the esker onto the
peatland was also determined.
Figure 3: Image created in Arc Scene. Yellow lines are transects that were
conducted on the peatland with the Geology Departments Ground Penetrating
Radar unit. Note the body of water (black)
in the center of the image does not have any of the esker body between it and
the peatland. This shows erosion of the
esker and GPR data shows possible esker material at base of peatland.
When looking at the mire from the standpoint
of figure 3, it is easy to see that the peatland is flat comparatively to the
esker that bounds it. There is the one
area where the esker has been eroded away.
This area is slightly different than what the tin is telling us. At the site, this area has been eroded away,
but not to the extent that the tin is allowing us to see. The tin is also being observed at a vertical
exaggeration of 1.5. This error appears
to be from the DEM. Part of the reason
as to why there appears to be no esker here could be because at this point the
esker is only about 8 to 10 m in height compared to other portions of the
esker which are upwards of 30 m in height.
This is a large difference which could be the reason why the esker here
is not seen.
The surface flow of the esker, figure 5, shows that
most of the water flows towards the western side of the peatland and meets up
with the hill seen in the aerial photo.
At this point the model shows that there is a lot of changes in
direction between each cell, but a general direction is seen towards the
north. On the near side of the esker
the surface flow seems to be jumbled at the peat and esker contact. This shows a flow to the northeast. There is an open channel of water here that
is fed by surface and ground water from the esker and from the groundwater
from the peatland.
The modeling that was done for the peatland
is slightly skewed because the water flow is over peat which absorbs water
very well. This does not allow for
surface water flow to occur very easily.
There must be a very large amount of rain to fall in order to have
surface water. Another problem with the
model is the micro-topography of the peatland.
The hummocks are large enough to divert water flow but not large enough
for a aerial photo to pick up, causing the problem with the model that was
created of surface water flow. The
surface flow would work much better if the model was completed on a surface
that did not absorb water so well.
Figure 2: Infrared
Aerial Photo of the esker-mire complex at Massawepie Boy Scout Camp. Color changes in peatland due to change in
vegetation type. Bright reds are pine
trees signifying sandy soil type.
Reddish purple are spruce trees.
In peatland whitish color are grasses and sedges with red being all Sphagnum.
Peatland
Esker
Figure 5: Surface
water flow map of the peatland. Table
on left shows how to interpret which direction each cell the surface water
would flow. Graph shows the
distribution of direction of water flow.
Table taken from Arc GIS help page for hydrology tools.
Flow Direction of Surface Water
Figure 4: TIN created
from the Longtom Mountain DEM.
Massawepie is located in the upper right of the TIN. TIN used to show general topography of the
area.
Massawepie
Mire
Figure 1: Map is the
depressionless hillshade of Massawepie Mire.
All sinks have been filled.
Table shows what the computer does to fill and remove areas of
sinks. Table taken from Arc GIS help page on hydrology sinks
and fills tools section.
Depressionless Hillshade of Massawepie Mire
I would like to thank Carol Cady
for answering my questions which tended to occur about every 5 minutes while
working on this project and throughout the whole semester. I would also like to thank Bill Olsen for
answering all my questions when Carol was either sick of me or when she was
not in her office.