ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

combined in a geographical information system to derive
thematic maps which can be extrapolated to larger areas of
the Antarctic Peninsula. The results beeing published by
Hochschild 1995: Geomorphologische Kartierung und
Untersuchung der Auftaudynamik mit Era-1-Sar-Daten im
Bereich der Antarktischen Halbinsel Bremer, Beitragc zur
Geographie und Raumplanung, show the potential of Ers­
1 Sar data to observe changes in the periglacial environment
by multitemporal analysis of 3 day cycle data. Composites
and difference images detected changes of the condition
of the snow cover or the moisture content due to
short time weather conditions.
Classification of geomorphological mapping units according
to the surface roughness has not been possible using
not Dtm corrected Sar data. The reasons for this are probably
the small scale inhomogeneous relief, the small differences
between the roughness indices and the unknow correction
factor for moisture differences.
This conclusions lead to the fact, that better results in the
analysis of periglacial landscapes will be achieved when
multifrequency Sar systems are on satellite platforms.
PETER HOLMES
Holocene geomorphic environments of the semi-arid
interior of South Africa
Department of Environmental and Geographical Science,
University of Cape Town, Rondebosch 7700, South Africa
A variety of geomorphic evidence in the semi-arid interior
of southern Africa (an area referred to as the Karoo), attests
to changing environments during the late Pleistocene
and on into the Holocene. This paper reviews the geomorphic
evidence for environmental change as reflected in
a number of upland depositional environments. The study
area is situated along an east - west transect, spanning some
600 kilometres in the region of 32° south latitude. The
majority of individual sites occur above an altitude of 1000
metres. Slope and pedogenic processes, as well as fluvial
and aeolian action have contributed to shaping these environments.
The paper goes on to review the significance of
the chronology from these environments at a local and subregional
scale. In particular, comparisons are made with
the findings of investigators who have worked on colluvial
deposits to the east of the Great Escarpment, where wetter
conditions currently prevail.
The depositional record from the Karoo records a shorter
time span of palaeoenvironmental change than do the depositional
environments to the east of the Great Escarpment
of southern Africa. Within the Karoo, it appears that
little depositional evidence predating the Holocene has remained
preserved within the landscape. Where deposits do
occur, they are primarily in the form of sedimentary fills on
206
valley floors. Many of these fills have been incised to bedrock
by gullying, thus exposing profiles for detailed geomorphic
analysis. The exception to the «valley fill» type
environments are Pliocene river terraces along the Orange
River, and isolated pockets of aeolian sand which were deposited
against valley flanks some 20 000 BP. A number of
shallow depressions or pans, with their associated lunette
dunes, also provide evidence for palaeoenvironmental
change.
The primary finding from this study is that the mid-Holocene
climatic amelioration some 5000 years BP manifested
itself in the semi-arid interior of South Africa in terms of
rapid landscape response to wetter conditions. This may
have resulted in the flushing out of any valley fills which
predated the mid-Holocene, and has resulted in an accumulation
of material from approximately 5000 years BP
onwards. The only older material to survive is that of aeolian
origin, presumably because of its sheltered position
away from drainage lines.
In summary, the current Karoo landscape contains an interrupted,
proxy geomorphic record of environmental
change dating back to the last glacial maximum, with only
the last 5000 years represented by what might be regarded
as a depositional continuum.
JANET M. HOOKE
Decades of change; geomorphology in fluvial
and coastal engineering and management
Department of Geography, University of Portsmouth,
Buckingham Building, Lion Terrace, Portsmouth, Hants. POI 3HE, UK
Major developments in the contribution of geomorphology
to engineering and environmental management have
taken place over the past ten years in the United Kingdom,
particularly in the coastal and fluvial spheres. Considerable
achievements have been gained in raising awareness
of the nature of geomorphic processes and their dynamics
and of how understanding of geomorphology can
help in effective management and decisions over engineering
strategies. Specifically, this has meant gauging or understanding
of interconnectedness in geomorphic systems
and the long-term variability of processes and landforms.
Radical changes in both policies and decision-making frameworks
have taken place such that the approach to coastal
and river management adopted by the British Government
is now to 'work with nature'. Likewise, management
structures have been emplaced to facilitate and encourage
integrated planning. Such changes have not, of course, occurred
from the influence of geomorphologists alone but
they do align policy much more with geomorphological
principles than in the past. Examples are presented of
geomorphological involvement in coastal engineering in