INTEGRATED USE OF TM IMAGE, DTM AND 3D VISUALIZATION IN
GROUNDWATER STUDIES ON KARSTIFIED MARBLES
A. Dimadi ^ *, M. Tsakiri-Strati "
* Dept. Geotecnical Engineering, Aristotle University of Thessaloniki, GREECE, adimad@civil.auth.gr
b = : ; « > ee = T = T
Dept. Cadastre, Photogrammetry and Cartography, Aristotle University of Thessaloniki, GREECE, martsak(@yvergina.eng.auth.gr
Working Group VII/3
KEY WORDS: Geology, Resources, Integration, Interpretation, Navigation, Visualization, DTM, Landsat
ABSTRACT:
The purpose of this study was the evaluation of integrated use of landsat TM imagery, Digital Terrain Model (DTM) and 3D
visualization for groundwater studies on karstified marbles. It was used a multispectral TM landsat imagery and a DTM that derived
from the topographic map. The study area is a mountainous area of karstified marbles in Northern Greece. The faults control the
hydraulic conductivity of the marbles, and their mapping is a very valuable means of identifying potential sites for groundwater
exploitations. Applied image enhancement techniques were used, such as: principal components analysis, empirical and statistical
procedures for color composite display of image, NDVI index and haze reduction in order to facilitate the detection of necessary
criteria, (which are various geological and geomorphological factors), for the fault structures mapping. Draping the orthorectified
image over the generated DEM in order to 3D visualization was applied. The supervised navigation on image 3D visualization was
improved the image interpretation. The results obtained have been evaluated using both an existing geologic map of the area and a
field investigation including: a) measurements of faults and definition of their nature, b) positions of springs, sinkholes, shallow
holes, an axis cave with subterranean river and c) the results of boreholes. The applied methodology shows that a large number of
fault structures were mapped, particularly in E-W direction and as a consequence a more completed net of faults was created.
Further more the tension faults N0°-20°, N50°, N90°, and N120°-160° show a greater hydraulic conductivity and delineate potential
sites for groundwater exploitations as the well yield data confirm this. The overall benefit of this methodology is the reduction of the
risk of low yield wells.
1. INTRODUCTION
The use of satellite images is one of the technique that are
available to hydrogeologists for locating and mapping linear
faulted structures which can be faults and faulted zones
(lincaments) (Sander et al, 1996). These secondary
permeability features control the permeability of carbonate
rocks those the primary porosity is usually extremely limited.
Consequently the potential sites for productive water wells are
located around the features with secondary permeability
(Parizek, 1975; Larsson, 1977; Dinger, et al, 2002; Travaglia, et
al 2003).
The advantage of the use of satellite images is that these cover
big and sometimes inaccessible areas, under uniform
conditions. Especially the capability of TM imagery to be
analyzed for enhancing the visibility of lineaments, contribute
to the effective study of lineaments on the earth surface.
This research presents a methodology of locating and mapping
faults in the area of west Falakro mount (East Macedonia-
Greece). This area is a rugged karstified carbonate mountainous
terrain and forms a geomorphological natural dam between
Drama basin and Kato Nevrokopi basin in the North. The study
area covers parts of two topographical maps at scale 1:50,000 in
UTM projection. These maps are used for the creation of the
digital terrain model (DTM) and for receiving the control points
for the orthorectification of the image.
* Corresponding author.
The criteria of localization and mapping the lineaments are: a)
the presence of vegetation, b) wetness, c) different slopes on
both sides along the lineament and d) different geological
formations on both sides (Meladiotis et al., 2001).
To facilitate the image optical interpretation for the lineaments
localization, the spectral characteristics of the image bands
were studied and the principal components transformation and
vegetation index were applied, as the statistical or empirical
procedures for image color display were applied (Yésou et al.
1993; Tsakiri, et al 2002; Tsakiri, et al 2003). Some of the
aforementioned criteria could not be detected so we applied the
supervised navigation on 3D visualization of DTM in
combination with orthoimage to facilitate the localization and
the mapping of the lineaments (Sarapirome, et al, 2003).
The hydrogeological importance of some particular fault
systems can be examined through their combination with karst
specific forms (sinkholes, shallowholes, caves), which usually
are developed along faults. So these fault systems can have à
secondary permeability and define probable general direction of
groundwater flow (Kresic, 1995).
The lineaments coverage layer was overlain on the digitized
topographic map (scale 1:50,000) for field checking. The field
reconnaissance has offered the identification of many
lineaments on the ground through their terrain features. The
majority of the lineaments are tensional faults and the drilling
290
Internati
He
potential
result of
In the fr:
of Land:
of acqui
km and
this (Fig
the orth
derived
UTM pr
Also gec
for the €
with res
Chagipai
Figure
3.GE
The stuc
North of
Falakro
between
and 1736
Southwa;
by the K
