Environmental Engineering Reference
In-Depth Information
Having spent much of my career studying streams in predominantly forested land-
scapes where forestry practices were the main human disturbance, I had a great deal
to learn about the threats facing streams in more urbanized catchments. Volunteering with
a river advocacy group in Atlanta, Georgia (Upper Chattahoochee Riverkeeper) opened
my eyes to the ecological conditions in urban streams, the limited scientific understanding
of these ecosystems, and shortcomings in current environmental policy and its implemen-
tation. Led by several of my graduate students, I began studying conditions in urban
streams around Atlanta. A review of urban stream ecosystems (
Paul and Meyer 2001
)
identified the many ways in which humans have altered these ecosystems (
Figure 16.5
)
and the gaping holes in our scientific understanding of them. Many of those holes still
FIGURE 16.4
Tanyard Branch, an urban stream on
the campus of the University of Georgia, which exhi-
bits many symptoms of the “urban stream syndrome.”
Its riparian zone has little vegetation, it is choked with
fine sediments, it receives storm-water runoff via pipes
from the adjacent parking lot, and parts of it are bur-
ied in culverts underground. In fact, just downstream
of this site, the stream flows through a pipe under the
football stadium. Is there a stream under the football
stadium on your campus? I've found that to be a fairly
common phenomenon on college campuses! (Photo by
J.L. Meyer.)
FIGURE 16.5
A simplified
diagram illustrating ways in which
the structure and function of urban
streams have been impacted by
human actions.
URBAN STREAM SYNDROME
Increased
imperviousness
Benthic
organic
matter
-
Flashy
hydrology
Loss of
vegetation
Altered and
contaminated
invertebrate
food webs
Habitat
-
Humans
Siltation
-
Contaminants
-
Primary
production
+
Excess
nutrients
