ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

MIHAELA DINU
Geomorphological hazards in the Getic Subcarpathians
and Piedmont
Department of Dynamic Geomorphology, Institute of Geography,
Romanian Academy, 12, Dimitrie Racovita, Sector 2,
Bucharest, 70307, Romania
The Subcarpathians are recognized as being one of the regions
in Romania most affected by intense geomorphological
hazards.
The Getic Subcarpathians, (the south-western part of the
Subcarpathians) and the Getic Piedmont, are hilly regions
in the South of the Southern Carpathians which have a
common and unique Quaternary and present-day evolution.
Built of folded and faulted Neogene molasse (Getic
Subcarpathians) and Quaternary deposits (Getic Piernont),
associated with a continental type of precipitation and specific
land-use (forest, pasture, orchard, arabilland) the regions
have very large areas affected by landslides and slumps
and intensive erosion. Many of the landslides and debris-flow
deposits exist in a fragile equilibrium, ready to
becoming destabilized by intense precipitation or seismic
activity. After a humid period (specialy May-June) associated
with snow melting, some catastrophic events happened.
Large areas are covered by mass movements and gully
erosion. Some of them are affected villages, routes,
railways, because the regions are also very old and well populated.
From the diversity of geomorphological hazards some case-studies
are presented herein.
NELSO C. DOFFO & GUILLERMO SAGRIPANTI
Modification in recent dynamics of hydric and fluvial
processes as indicators of neotectonic activity
in Sampacho, Cordoba, Argentina
Departament of Geology, University National de Rio Cuarto, Route 8,
km 601. Rio Cuarto, Argentina
The structural pattern for the perimountain area that
drains the eastern slope of the plutonic-metamorphic complex
called Sierra de Comechingones, consists of differentially
thrusted and tilted blocks, mainly towards the East
and South East with asymetric profiles of steeper slope on
its western front. These profiles, at regional level, constitute
the most important factor in relief control, defining in
depressed sectors, alluvial accumulations and basin divisions
in structural hills, some of the them with base outcroppings.
The superficial drainage, besides presenting a
marked structural control, shows evidence of neotectonic
activity favoring the development of new processes and in-
tensifying the increase in vertical crack rate, piracy and
drainage network hierarchy, among others. The dynamics
of undergroud water is greatly influenced by the structure,
as shown by the presence of marshes and lacoons along the
failure scarpment. Most of the zone is covered by holocenic
deposits of eolic and alluvial origin, with slopes ranging
from 1 to 30/0.
The seismological history, the remarkable seismic activity
rate and the geological and geometric characteristics of the
existing structures define the region as seismically active
with an effect on the neotectonic dynamics.
The antagonic response of exogenous agents masked, as in
this case, by climatic variations and by the farming activities
developed on this soil, shows however qualitative and
quantitative differences in those tectonically active sectors.
The purpose of this paper is to propose a methodology
that would allow on the one hand to define from the analysis
of exogenous dynamics, the presence and activity of potential
earthquake generating structures, and on the other,
to be used as a tool for the prediction and estimation of
earthquake recurrence in failures of interplate regions considered
nowadays to be aseismic.
WALTER DRAGONI & DANIELA VALIGI
Some considerations regarding climatic change
and specific erosion in Central Italy
Dipartimento di Scienze della Terra, Universita di Perugia,
piazza dell'Universita, 06100 Perugia, Italy
Global, Circulation Models (Gems) predict a rise of
between 0.5 to 3 "C in the average atmospheric temperature
in the Mediterranean area over the next fifty years, based
on the increase in the amount of CO 2 in the atmosphere.
The predictions for precipitation in the Mediterranean
area are less certain: according to the different models, it
could vary between +300/0 and -30% of the current mean
values (Wigley, 1992; Ipcc, 1995). This variation will undoubtedly
have an effect on the hydrological cycle. The
analysis of the longest and most reliable time series for central
Italy (Perugia and Rome) indicate that a rise in temperature
of approximately 0.5 -;- 1°C/100 years and a decrease
in rainfall of about 2 mm/year are now taking place.
These climatic variations, regardless of their causes, involve
significant geomorphological consequences, the most
evident being the phenomenon of soil erosion. In the absence
of measurements, soil erosion can be estimated using
empirical formulas. That which is most commonly used,
although it is not very recent, is the Fournier formula
(1960):
log D.S. =2.65 i"log (p2/P) + 0.46 i"log ( H "tg a) - 1.56
where:
D.S. = specific erosion (t/kmi/yr); p = rainfall in the rai-
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