ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

This action has been changed by volcano-tectonic events
with subsequently submersion or uplifting of large coastal
areas in different times as well as Roman Period, Middle
Age and last two centuries . The stratigraphy of «La Starza»
terrace (11-5 Kyrs B.P.) with its marine and continental
deposits results from this events. As well as the roman
age ruins of villas and harbours and the middle age handmade
(Miseno, Posillipo and Pozzuoli) nowadays submerged
or buried under beach deposits. Quite surely those
vertical movements have interacted with glacio-eustatic rising
of global sea level during Holocene. The soil fluctuation
(locally named «bradisismo») has played an important
role during the last 2,000 years in this area. In fact the most
recent bradiseismic crisis (1970-1972 and 1982-1984)
have caused a maximum soil deformations of about 2 m on
Rione Terra (Pozzuoli) and the uplifting of the West coastal
area of the plain (about 1 m in La Pietra, nearby Pozzuoli;
about 0.5 m at Bagnoli and about 0.2 m at Coroglio,
towards Naples) as well as the partial emersion of submerged
beach, with consequent widening of the emerged beach
and seawards prograding of the shoreline.
Stratigraphic reconstruction of the first 20 m depth of
plain subsoil, derived by the study of drillings and sedimentological
analysis of samples, pointed out a recent regressive-transgressive
phase (after N.Y.T. eruption) with
deposition of submarine beach sediments (volcanic sands
and pebbles) and continental too (pomiceous levels), palustrine
(silt and peat levels) and emerged beach sediments
(reddish dune sands).
In the central place of the plain has been find two levels of
peats lower then the present sea-level, the former one
between -0.70/-2.70 m and the latter between -4.50/-7.70
m. Their ages determined with HC method are fixed respectively
at 3700 +/-55 and 1860 +/-50 years B.P. Previous
researches have reconstruct the morphological evolution
of Bagnoli coastal plain until the uplifting of La Starza
terrace and formation of Mount Spina volcano, both related
to the last volcanic events (4-:- 3.6 Kyrs B.PJ. After
Mount Spina eruption took place the post-volcanic collapse
of the area with the origin of the coastal plain.
Historical informations and data about the bradeisismic
and volcano-tectonic phenomena are known from the Roman
Age until today. Therefore the new datings help us to
evaluate the time gap between 4 and 2 ky B.P. and also to
estimate about 8 m the total subsidence degree in the plain
during the last 3.7 Kyrs with an average rate of 2 mm/y.
DAS DEBASHIS
Role of configuration of terrain to determine agricultural
landuse in Birbhum district (West Bengal, India)
Geography Department, Visva-Bharati University,
Santiniketan, Birbhum, West Bengal, 731235, India
A. Terrain configuration is so dominant factor in the Human
society and environment that its influence on the pattern
and destiny of agriculture is immense.
B. The study possesses following objectives:
i) To examine the nature of relationship between absolute
relief and agriculturallanduse.
ii) To assess the interrelationship that exist between relative
relief and agriculturallanduse.
iii) To study the nature of association between disseetion
index and agricultural landuse,
iv) To enumerate interdependence between slope of the
terrain and agriculturallanduse.
C.
i) Analysis of absolute relief has been done by dividing
contour map of the study area into units and nothing the
mazimum altitude in different units with the help of contours
and spat heights.
ii) Relative relief represents the difference in elevation
between the highest and the lowest points falling in an unit
area.
iii) Dissection index is the ration between relative relief
and absolute relief.
iv) Slope analysisis based on the wentworth's method of
slope analysis.
v) Composite index of agricultural efficiency is computed
D. In general, altitude of the land is inversely proportional
to agricultural development. Therefore, the region with high
absolute and relative relief large proportion of dissected
land, and with relatively steeper slopes have smaller proportion
of net sown area. Most of the farmers of that region
cannot practise multiple cropping extensively and
therefore, the region achieves lower degree of agricultural
development. However, this generalised observations are
strictly confined to the macro level studies, but not so at
micro level. In developing country at the macro regional
level, the physical factors basically determine the nature of
cropping pattern, land utilisation and levels of agricultural
development to a significant extent. Where appropriate technology
and modern infrastructures, facilIties are either
absent or are located at the small pockets of land. On the
other hand, at the micro regional level, the agricultural
aspects are influenced largely by the technological, socioeconomic
and infrastructural factors. As far example at the
village level study of Rajnagar and Moyureswar II block
the villages with relatively higher slope or higher relative
relief also may achieve higher degree of agricultural development,
because, here the magnitude of slope or relative
relief is not considerably high which can create constraint
to agricultural development, as it may be the case in West
Bengal and in Birbhum.
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