Alyssa James
GEOG 591
Exercise 1
1) Describe those areas in New Hope area that fall into each class
a. NCLD Urban >20:
This map displays upstream drainage areas that are heavily urbanized and all stream
reaches that have local contributing catchment areas that exceed 20%. Heavily
urbanized areas are defined as the percentage of catchment area as Low Intensity
Residential, High Intensity Residential and Commercial/Industrial/Transportation that
exceed 20%. Majority of these heavily urbanized areas are located in the North and
Northeastern section of the New Hope Watershed. These areas do not extend down
into Jordan Lake. These areas stem from Chapel Hill, Durham, and Raleigh (not Raleigh
in New Hope area (-0.5)). More urban streams are concentrated around Durham than
any other area in the New Hope Watershed.
b. CUMNCLD Urban >20:
This map displays the reaches and streams that have local urban drainage areas but not
cumulative upstream urban areas (This is the definition of Urban > 20 (-1.0)). The
same definition of heavily urbanized used in the previous map is used in this map. A lot
of these areas overlap portions of the NCLD Urban >20. However, one portion of this
area extends down into the tip of the Jordan Lake. Again, the majority of these heavily
urbanized areas are located in the Northeastern corner of the New Hope Watershed.
This shows that most of the water that collects in these areas drains into these areas as
well.
c. CUMNCLD Urban >20 and NCLD Urban <20:
This map displays reaches and streams that have cumulative urbanized upstream areas,
but local catchment areas that are not urban. The upstream urbanized areas are near
Chapel Hill, Raleigh, and Durham. These areas are relatively small compared to the
CUMNCLD Urban and NCLD Urban. It is concentrated in the Eastern section of the
watershed, and extends down into the Northern reaches of Jordan Lake
Cumurban_nourban_stream is connected to Jordan Lake. In conclusion, New
Hope area, one of the main drainage areas of Jordan Lake can be characterized
as urbanized area when considering the whole upstream area of New Hope
creek (-1.0).
2) Comparing step 1 results, which urban area correspond to high stream discharge area? What
does this mean in terms of water quantity and quality problem of not only watershed itself but
also Jordan Lake?
a. Chapel Hill, Durham, and Raleigh are the urban areas that correspond to high stream
discharge. This is probably due to the significant amount of pollutants and impervious
surfaces common to urban areas.
b. Since these urban areas are contributing to the high stream discharge, it is appropriate
to assume that the quality of the watershed is worse than other watersheds with less
urbanized areas. Also, many people live in these urban areas and all share the water;
for this reason, the quantity of water must be pretty small. This also affects Jordan Lake,
Alyssa James
GEOG 591
Exercise 1
since it is downstream from these urban areas. The pollutants that collect upstream
from Chapel Hill, Durham, and Raleigh eventually travel downstream and deposit in the
lake. This is harmful to the many species that live within and around the lake that use
the water. Further, as the urban areas upstream consume massive amounts of water,
there is less fresh water to travel downstream to the lake. There is also the issue that
other communities and habitats within the watershed are being affected by the
pollutants that they are not creating. This exemplifies the fact that a watershed is a very
delicate structure that everyone and everything within its limits share.
(22.5/25)
Alyssa James
GEOG 591
Exercise 1
Alyssa James
GEOG 591
Exercise 1
Alyssa James
GEOG 591
Exercise 1
Alyssa James
GEOG 591
Exercise 1