ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

carried out in this area. The above mentioned problems
are the subject of further investigations.
ALLAN JAMES
Time and the effectiveness of alluvium:
river engineering, fluvial geomorphology,
and mining sediment in California
University of South Carolina, South Carolina, U.S.A.
River managers need to understand a fluvial system as it
has changed and continues to change through time. Many
modern river systems are presently in a state of flux due to
substantial human-induced changes to water and sediment
regimes and the hydraulics of channels. Yet, historical approaches
to understanding river systems rarely receive adequate
attention because historical methodologies are not
conducive to the application of quantitative analysis such
as numerical modeling. While there is a loss of precision in
using most historical reconstructions, the information derived
from these studies is essential to a full understanding
of the behavior of fluvial systems.
This study presents examples of channel morphological
changes brought about by two episodes of sedimentation
Irom hydraulic gold mining. The primary event was the
production of more than 1 billion m' of sediment from
1853 to 1884 which caused massive aggradation across the
Sierra foothills and Sacramento Valley. Modern notions
that geomorphic responses to this event were relatively
ephemeral are not borne out by field and historical data.
The assumption that sediment loads have returned to previous
levels and that deposits have stabilized is not supported
by empirical evidence. A secondary sedimentation
event, not previously studied, was the production of about
24 million rn' of sediment during a period of licensed mining
from 1893 to 1953.
This episode of sedimentation has been largely overlooked
as a geomorphic, hydrologic, or water quality event. Yet,
channel morphologic responses in phase with mining during
this period are demonstrated in the Sacramento Valley.
MANTU M. JANA
Application of remote sensing techniques to study fluvial
processes and associated landforms in the Terai
of north Bengal, India
Department of Geography & Applied Geography
North Bengal University, Darjeeling, India
The Terai of North Bengal lies between the mountains of
the Himalaya and the plains of North Bengal. Geological-
ly, it is a short of neutral country, being composed neither
of the alluvium of the plains nor of the rocks of the mountains
but most part of alternating beds of gravels, sands
and boulders brought down by the numerous mountain rivers
of the Himalaya. After cutting across the ridges, these
rivers debouch into the Terai and carry huge load of sediments
both in suspension and traction. Most of these bed
loads are deposited as fan deposits. Moreover, gradual rise
of river beds has resulted in severe bank erosion and causes
overflow. The shifting or rivers from west to east in this
region is due to tectonic activities in the recent past. As a
result, numerous abandoned channels with various degree
of aggradation in both older and the present flood plains,
palaeo-channels, cut-off menders and ox-bow lakes were
formed in different parts of the Terai.
The major agency shaping the morphology and landforms
of the Terai is fluvial. A number of terraces composed with
unassorted rocks which owe the origin to river action are
found on both sides of major rivers and these are identified
on satellite imagery. There are many extensive outwash
gravel plains and piedmont plains in the Terai. Terraces
of the Tista river are originated due to glacial or glacio-fluviatile
processes. A number of marshy areas were formed
due to channel instability. The geomorphic processes accompanied
by tectonic movements have produced rugged
hilly tracts, dissected slopes of hills and rejuvanated valleys.
The nature of Quaternary sediments indicates the
process of glacial activities in the past. The region experienced
a multicyclic landscape due to varied soils, complex
drainage systems and under fluvial and fluvio-glacial
environments. The landscape in the region is most complex
and such complications are influenced by neo-tectonics,
variation of physio-chemical processes and climatic
characteristics. Various fluvial landscepes in the region were
sculptured by the fluvial actions in the recent past and
the modifications are still going on to form the present
landscape. Now-a-days, remote sensing techniques are most
important tools for study the fluvial processes and resulted
landforms in such a region like Terai of West Bengal.
JACEK JANIA
Linkages between dynamics of the hans glacier
(Spitsbergen) and morphology of its marginalzone
Department of Geomorphology, University of Silesia,
Bedzinska 60, 41-200 Sosnowiec, Poland
Differential dynamics of a tidewater glacier and geomorphic
consequences in relief of its marginal zone has
been studied. The Hans Glacier (57 km') is one of the best
studied glaciers in Spitsbergen (Svalbard). Glacier velocity
and front fluctuations has been surveyed by terrestral photogrammetry
several times a year since 1982. Classic field
geomorphological mapping and interpretation of aerial
photos have been used for analysis of the spatial distribu-
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