|
Seismic
Sequence Analysis by Frequency Transition: A Case Study from
the Himalayan-Tibet Areas
--Syed
Mustafizur Rahman, M Rezaul Islam,
Mumnunul Keramat and Md.
Sultan-Ul-Islam
Frequency contents
of a seismic trace, varying with time carry information about
the properties of the subsurface reflectivity sequence. In
this paper, frequency transition technique for the reflection
sequence analysis of the seismic data has been presented.
The technique is the extension of the frequency attributes
representation of seismic data. Frequency attributes, separate
display of the seismic time amplitude maps, are computed with
complex trace analysis. Moderate and sharp frequency variations
are found all over the traces with time. Sharp frequency variations
and the time of appearance are termed as transition frequency
and transition time respectively. Transition-factor (T-factor)
has delineated for marking the sharp frequency variation in
the time frequency plots. T-factor differentiates high, moderate
and transition frequency variations. The technique is explained
with examples and has been applied for studying the reflection
sequences of the INDEPTH seismic data. The proposed seismic
reflection analysis can be used to identify the strata by
sequence stratifying the seismic data.
©
2008 IUP . All Rights Reserved.
Preliminary Hazard
Assessment by Integrating Geophysical and Other Data Sources,
NW Gulf of Suez, Egypt: A GIS Multicriteria Approach
--A
M Youssef and E Tarabees
Urban, industrial
and tourist developments are considered of high priority in
Egypt. The study area is located on the NW bank of the Gulf
of Suez, approximately 20 km south of Suez city. It is one
of the promising new development areas for public, industrial
and tourist activities. The development area encounters several
geoenvironmental problems that may limit its suitability for
civil projects. In the current research, the preliminary hazard/suitability
site investigation for rating different environmental, geological
and geotechnical conditions facing civil projects were assessed
using a Geographic Information System (GIS). Previous methods
focused on one aspect, while ignoring the rest. However, with
the advantage of GIS, a weighted GIS model integrating different
types of data, such as landuse/cover, geological, geomorphological,
geophysical, environmental, remote sensing, and field data,
can be established to create a suitability/hazard map for
the area. Analytical hierarchy process (AHP) approach was
used to develop the weighted model for different factors.
As a result of this study, areas of potential geotechnical
and geoenvironmental hazards that could impact the design
and construction of civil projects have been identified. Also,
changes can be made early in the design process before significant
design effort is invested.
©
2008 IUP . All Rights Reserved.
Estimation of
Aquifer Thickness from Vertical Electrical Sounding Data (Schlumberger
Method) in the Area Near Malanpur, Bhind (MP)
--Vineesha Singh and M C Khare
Groundwater is characterized
by a certain number of parameters, which geophysical methods
try to determine from surface measurement mostly indirectly,
but sometimes directly. Groundwater is a primary input for
the sustainable development of an area. It plays a protective
role against the vagaries monsoon. The surface resistivity
sounding is very much effective in estimating aquifer thickness
and basement topography which help in identifying various
suitable sites for groundwater exploration. On the basis of
prevailing hydrogeological conditions, subsurface lithology
and the result of geophysical investigation in various locations
for construction of borewell, dugcum-borewell, etc., a subsurface
geoelectrical survey, using Vertical Electrical Sounding (VES)
method and borehole logs, was carried out around Malanpur
area of Bhind district in order to investigate the aquifer
characteristics and thickness and assess their groundwater
potential in the study area. Nine Vertical Electrical Sounding
(VES) were conducted within the area and its environment using
the Schlumberger array configuration for identifying the horizontal
and vertical variation in subsurface lithology and depth of
rock. The data were interpreted using curve matching method
(Orellana and Mooney, 1966). The geoelectrical data of layers
and parameters have been correlated with the lithology borehole
drill in the study area. The result reveals that four layers
belong to H, A, and K type curves. The aquifers thickness
varies between 3.0 m and 42.0 m; the resistivity of the topsoil
5.5 to 260 Wm; pebble and kankar mixed layers varies between
1.7 and 32.50 Wm. Aquifer resistivity ranges from 10.5 to
280 Wm.
©
2008 IUP . All Rights Reserved.
GIS Point Scoring
for Good Water Bearing Zone Identification at Sweta River,
Kallar Basin, Tamil Nadu, India
--Gurugnanam
B, Prabaharan N, Vasudevan S, Sulochanasekhar4 and Lingeswara Rao S V
In this paper, an
attempt has been made at Sweta sub basin, Kallar basin, Tamil
Nadu, where sites for groundwater exploration have been demarcated
applying geophysics and GIS technique using Arc GIS software.
In this paper, the geophysical output was taken to GIS platform,
where the point scoring of the individual theme followed by
the final map was assessed to predict the water bearing formation.
The total work is executed with the weighted rating analysis
in GIS environment. Spatial and non-spatial data was analyzed
in GIS in a quick and efficient way. The term `geographic'
in GIS refers to the locational attributes which define the
spatial positioning of the piece of information on the face
of the earth. The advent of digital computers with high data
processing speed and the development of analytical tools in
GIS have helped in handling geographically referenced data
with ease and flexibility. Of late, computer-aided GIS has
become a reality. Using of GIS in hydrogeology is only at
its inception, but there have been cases of some successful
applications.
©
2008 IUP . All Rights Reserved.
Application of
Rule-Based Mamdani Type Fuzzy Modeling to Quantitative Damage
Analysis of Indian Earthquakes
--S
Vijayachitra and A Tamilarasi
Due to very hot climatic
conditions and tottering land forms, India is one of the developing
countries vulnerable to earthquakes. It is difficult to have
a mathematical model for analyzing the damage caused by earthquake
because of its complex behavior, influent characteristics
and environmental conditions. In order to facilitate decision
making and planning for earthquake management, it is necessary
to be prepared for a rapid and knowledge-based response to
provide a proper estimation about the damage. Since no intelligent
model has been proposed in India yet, devising such a model
seems to be absolutely essential. In this paper, a Mamdani
Type Fuzzy Inference System (MTFIS) is employed for the damage
analysis of earthquakes which includes the complications of
defining, assessment and modeling the variables involved as
well as handling uncertainty. The resulting conceptual fuzzy
model contains the robustness of fuzzy systems which can adapt
to various situations.
©
2008 IUP . All Rights Reserved.
Remote Sensing
for Deriving Neotectonic Evidences from Disorganized River
Course and Riverine Geomorphology of Mendha River Area, Rajasthan
--V
S Rathore and M S Nathawat
Geomorphological changes,
such as river system disorganization and disappearance, were
noticed on satellite imagery in northwestern India. The present
study was carried out in Mendha river catchment which displays
peculiar linear structures and abrupt changes in river course
on satellite images. Remote Sensing satellite data also have
been found very useful in the delineation of lineaments. Thus,
the IRS-1D LISS III image of 2004 and Landsat FCC image of
1975 were used to delineate lineaments, river course dynamics
and recent geomorphological changes. For this the visual interpretation
and digital image processing of the satellite data were performed.
The regional lineaments were also utilized to understand the
tectonics of the area. It is observed in the study that the
Mendha river is structurally controlled and shifting its course,
also geomorphic features of recent origin are identified.
From these observations, it is inferred that the catchment
area is neotectonically active.
©
2008 IUP . All Rights Reserved.
|
