Urban Areas > 20% Urbanization Map (#1)

GEOG 591, A. Permar Exercise 1 January 27, 2012

Cumulative Urban Areas > 20% Urbanization Map (#2)

1 GEOG 591, A. Permar Exercise 1 January 27, 2012

Cumulative Urban Areas Upstream > 20% Urbanization w/ Local Urban Streams <= 20% Map (#3)

Mean Annual Flow > 30 cfs Map (#4)

Question #1: Describe those areas in New Hope area that fall into each class.

In consideration of local urban drainage areas as compared to cumulative upstream drainage areas:

As illustrated in the maps above, there is a great degree of overlap between those local urban drainage areas that are characterized by heavy urbanization and those heavily urbanized cumulative upstream urban areas. Where these two descriptive classes differ, it appears as though the cumulative upstream reaches with heavy urbanization typically have longer stretches of streams/water courses that are described as heavily urbanized (>20% urbanization) than do their downstream, local catchment counterparts. These observations make sense because local urban drainage areas are members of cumulative upstream drainage areas.

In consideration of regions with cumulative upstream drainage areas > 20% urbanized and local urban drainage areas <= 20% urbanized:

This map illustrates many portions of the longer stream reaches mentioned above where there is not overlap between the heavily urbanized cumulative upstream drainage areas and local urban drainage areas (not heavily urbanized). Interestingly there are many small stretches of streams that fall into this category, the majority of which are situated proximal to the Jordan Lake Reservoir and other smaller water bodies/sinks distributed throughout the region. This makes sense demographically, since typically more humans draw water from a reservoir than the number that actually live near it. Overall the map

3 GEOG 591, A. Permar Exercise 1 January 27, 2012 indicates there are not very many stream reaches in the New Hope area with heavily urbanized cumulative upstream drainage areas and without heavy urbanization of the local catchment areas. 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).

Question #2: Comparing step 1 results, which urban area(s) correspond to high stream discharge area(s)? What does this mean in terms of water quantity and quality problems of not only the watershed itself, but also Jordan Lake?

Local urban drainage areas and cumulative upstream drainage areas appear to be stressing those stream reaches characterized as having mean annual flow > 30 cfs. (This is illustrated by the degree of overlap between maps 1, 2, and 4.) Additionally the cumulative upstream drainage area maps portray some direct overlap with stream reaches north and east of Jordan Lake Reservoir that have > 30 cfs. The map displaying all stream reaches with mean annual flow > 30 cfs indicate there are long stretches of streams on all sides of Jordan Lake Reservoir (in all cardinal directions) with MAFlowU > 30 cfs; comparison of this map with the others (1, 2, & 3) indicate most urbanization has thus far been concentrated to the north and east of JLR.

With this in mind, it appears as though the northern and eastern regions of the watershed are differentially stressed relative to the other regions; this has implications for the stability and overall integrity of the watershed. The uneven stress on water resources in the eastern and northern regions of the watershed indicates that too many people are tapping into not enough water, which likely a) downgrades the streams, b) contributes erosive forces to the water systems, c) necessitates alteration of natural stream flow patterns via conduit installation, d) reroutes the streams, e) restructures the watershed. Stream quality often declines with human abundance due to a number of factors, many of which can be classified as different means of degrading the waterways which are so vital to life sustenance.

Jordan Lake Reservoir is likely overstressed for similar reasons (as those already mentioned); an unbalanced extraction of its hydrological resources to the north and east can lead to unsustainably low reservoir levels and degraded water quality. Recreation (e.g. boating, swimming, fishing, hiking) on and around the lake also serves to degrade the quality of JLR resources.

One could forecast that future urbanization will spread throughout the region to the western and southern watershed regions, because the migratory routes of people are usually linked to the flow of water.

High stream discharge areas are overlapped mostly with urban and cum_urban stream. Since runoff from urban is characterized by surface runoff, which is direct, fast and wash-off the contaminants in impervious area, it threatens water quality problem to Jordan Lake (-1.0).

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