Tyler Tran
Tyler Tran
Tyler Tran
Question 1. Describe those areas in New Hope area that fall into each class.
-Heavily urbanized upstream drainage areas include mostly the northern section of the New
Hope watershed, encompassing both Chapel Hill and Durham in the northeast reach of the
watershed. This also includes interstate 40 running between Chapel Hill and Durham, which
would increase urban runoff to streams which eventually flow to Jordan Lake.
-Areas that have urbanized local drainage areas but non-urban cumulative upstream areas include
scattered areas north of Jordan Lake where there is urbanization at specific points (localized), but
without additive or cumulative effects of urbanization in the streams. The local urban areas
receive cumulative flow draining from non-urban areas. The urbanized local areas are likely
suburban areas around Fearrington, with the non-urbanized cumulative areas likely being
forested lands or more rural areas that are less developed. Your map looks good. Just one thing I
like to comment is that these are the areas where the watershed itself is urbanized regardless
of upstream area. So it is not easy to say that these areas are less (or much) urbanized than the
areas of first map. We should check the % urban of each individual area if we want to compare
the first and the second stream area. For example, Morgan Creek is heavily urbanized area (1.0).
-Areas with cumulative urbanized upstream areas but local catchment areas that are non-urban
include continuous flowlines northeast of Jordan Lake. The selected areas receive flow from
upstream areas that are urbanized, though the specific selected areas are not urbanized
themselves. The non-urbanized local area is likely riparian buffer or undeveloped area
immediately surrounding Jordan Lake, while the cumulative urbanized flow is likely a
combination of Chapel Hill and Durham. 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).
Question 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?
The non-urban local drainage/urban cumulative upstream drainage corresponds to the high
stream discharge area, likely a result of higher urbanization levels of Chapel Hill and Durham,
which contribute to the urbanized cumulative flow into this area. Specifically, there are three
arms that extend northward with highest mean annual flow. The most easterly seems to source
from the Town of Chapel Hill, the central arm seems have sources in the 15-501 area, and the
easterly arm is likely related to interstate 40. Higher urbanization would contribute to higher
Tyler Tran
quantity of runoff water and lower water quality of the runoff. In urban areas with a high
percentage of impermeable surfaces, runoff water accumulates quickly, carrying with it
pollutants from those surfaces. This leads to not only degraded localized water quality in the
urbanized areas within the watershed, but also lower quality runoff water flowing into Jordan
Lake, as pollutants accumulate into the runoff from the upstream urbanized areas.
(23/25)