ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

exceed 20-30 m. Presently, most of these depressions are
taken over by lakes.
Disjunctive tectonics covered the denudative relief giving,
as a result, a complicated system of denudative and tectonic
elements. Exaration activity of Pleistocene continental
glaciers led to the depreparation of structural relief and inconsiderable
remodelling of its elements.
JON HARBOR
Engineering geomorphology at the cutting edge
of land disturbance: erosion and sediment control
on construction sites
Department of Earth and Atmospheric Sciences,
Purdue University West Lafayette, IN 47970-1397, USA
Construction site management, traditionally dominated by
professional engineers, provides an important opportunity
for engineers and geomorphologists to work together in
minimizing the environmental impacts of land disturbance.
Areas disturbed for construction activity have soil erosion
rates 2 to 40,000 times greater than pre-construction conditions,
and are an important component of nonpoint source
pollution that degrades surface water quality. Despite significant
local- to watershed-scale environmental and economic
impacts from increased erosion and sedimentation, the
lack of an individual economic incentive for land developers
to control erosion has limited voluntary adoption of
erosion and sediment control measures. However, increased
regulatory requirements, combined with efforts to
identify and publicize the benefits of erosion control, are
increasing the number of construction sites on which erosion
control efforts are being implemented.
Geomorphologists have the opportunity to play an active
role in erosion and sediment control by implementing
knowledge of erosion and sedimentation processes and of
the variables that effect these processes. Pre-project geomorphological
site assessments allow project designers to
work around areas with high erosion potential, and to stage
and schedule land disturbing activities to minimize erosion
potential. Combined engineering and geomorphological
analyses can increase the likelihood that on-site and offsite
streams and drainage channels are stable under altered
hydrologic conditions, both during and after land use
change, and can be used to design a drainage plan that minimizes
surface water flow in disturbed areas. A variety of
temporary measures to reduce erosion and to trap sediment
on site can be designed and implemented, such as
temporary surface covers, silt fence and sedimentation basins.
However, design and implementation of these measures
requires an understanding of erosion and sedimentation
processes, and in many cases incorrect installation and
maintenance limits their effectiveness. Regular on-site inspections
and training by geomorphologists specializing in
198
erosion control can ensure that measures are being installed
and maintained correctly, and allows the inspector to
modify the erosion control plan to deal with changing conditions
and unanticipated problems. In addition, geomorphologists
and engineers can use their combined understanding
of erosion processes and construction site realities
to develop innovative, practical measures to improve
erosion control.
Construction site erosion control is a field that relatively
few academic geomorphologists have shown an interest in,
yet has great potential both in terms of job opportunities
and research. It is an area in which geomorphologists and
engineers can work together, using their complementary
knowledge both for the development and implementation
of erosion control plans, and as the basis for developing innovative
practices and for undertaking research on the effectiveness
of traditional and new approaches to erosion
control.
CAROL P. HARDEN
Effects of land-use change on hilIslope hydrology:
two contrasting cases
Department of Geography, University of Tennessee, Knoxville,
Tennessee, 37996-1420, USA
Predicting and extrapolating rainfall runoff and soil erosion
rates over entire drainage basins requires understanding
the relationships between land-use and hillslope processes.
To meet the increasing demand for spatially-extrapolated
runoff and erosion rates in Gis applications and to
support the development of more accurate environmental
models, closer examination of the land-use variable will be
required. Two cases from this author's experience reveal
the need to determine land-use history as well as contemporary
land-use and the need to develop land-use classification
schemes that include hydrologically and erosionally
relevant classes. One case is from a humid, hilly region of
eastern Tennessee, in the southeastern USA; the other
from a watershed in the Ecuadorian Andes in South America.
In both cases, a hand-portable rainfall simulator-infiltrometer
was used to replicate a standard rainstorm, and
infiltration and sediment detachment were measured.
In the Tennessee case, the Copper Basin, 130 km 2 in area,
had been dramatically eroded by more than 100 years of
copper mining and smelting. The basin was so denuded of
vegetation that it became a biological «desert,» and a feature
clearly identifiable from space. Acidic fumes from
copper smelting and sulfuric acid production, along with
some grazing of livestock, maintained the barren state and
impeded revegetation efforts for decades. Reforestation
has been more successful since the 1970s, and, today, the
basin is essentially revegetated. Rainfall simulation experiments
in sections of the basin that were revegetated during