the toe-failure process, a wide zone of up-
liftings was formed around the dump. This
zonecovers not only the close surroundings
of the dump body buto. also a far forefield
up to 350 m.
As a result of toe-failure, the layer of
organic soils is destroyed and phosphogyp-
sum can have direct contact with the water-
containing sands and gravels layers. As a
consequence, the contaminations can easily
penetrate to underground water causing its
poli ution by toxic and radioactive compo«.
nenis. The contaminations can also freely
migrate with rainfall-water to the nearest
channels and the Odra river. Water-soluble
components and suspended matter, which flow
down with surface water run-off are the main
degradating factors to the open-water envi*.
ronxnent, even far from the dumping area. It
must be stressed that degradating factors
are active foralong time, have a wide-range
of Lnfluence, and their impact cannot be
controlled. That is why, the use of remote
sensing techniques for an environmental in
ventory was justified.
The following remote sensing experimental
images were taken:
1. Aerophotogrammetric black and white
photos ( 6 series, approximate scale vary
from 1:2500 to 1:4000 ) ;
2. Infrared photos - taken by a small for
mat camera (2 series, approximate scale
1:10 000, 1:8000);
3. Colour aerial photos - taken by a small
format camera (1 fly, aproxímate scale
1:8000);
4. Multispectral photos - taken by a four-
band NAC camera and MSK-4 Carl Zeiss Jena
camera (3 series, approximate scale 1:10 00C).
5. Thermal infrared aerial images - taken
by an AGA-780 with magnetic recording;
6. Thermal infrared terrestial images -
taken by an AGA-780 Thermovision System.
All the materials listed above were used
for qualitative study. Photogrammetric pho
tos were also used for mapping the dumping
area, tracing the terrain and dump deforma
tion, and calculating the volume of heaped
and uplifted masses. 3
3 RESULTS
The results of the photointerpretation stu
dies have shown that the phosphogypsum dum
ping process should be considered within
the two following aspects:
1 . ijow engineering-geological conditions
affect the technology of dump formation, and
2. What impact it has on the natural en-
vIronment.
The impact of both elements depends mainly
on the dump base instability. The shifting
of the dump front is the cause of the pro
pagation of the deformation process in dis
tant parts of the forefield and can provoke
a hazard for objects and constructions si
tuated close to the dumping area, as well
as danger for heaping-machine operators.
In the uplifted zone the intensive mass mo
vement can be seen. As an effect of it com
plicated folding, forms are created which
can reach up to 10 m in height above the
original terrain surface (/Figure 2 ) .
The photogrammetric measurement has shown
that the mass displacement within the toe-
failure zone varies from 10 to 30 cm/day.
On the aerial photos it is easy to recogni
ze all the structural elements which exist
Ln a forefield (uplifted zone contour, fol
ding forms) as well as within the dumo bo-
Figure 2. The toe-failure zone in the dump
forefield.
Figure 3 • The typical dump body deformations,
dy (cracks, fissures, dump body dislocations,
and toe-failure origin slides, which may ap
pear in the front zones of the dump, see
Figure 3).
It was also stated, on the basis of thoro
ugh analysis of all remote sensing date,
that the toe-failure process is not a conti
nuous one, but is a cyclic one due to the
continuous movement of the dump front.
This conclusion was drawn on the basis of
an analysis of the shape and situation of
a toe-failure zone border, as well as, the
directions of uplifted mass dislocations,
which were registered on the succesive se
ries of photos.
A photointerpretation made it possible to
distinquish at least the two following pecu
liar sta
- a prel
_ a stag
The pr
mainly b
occur wi
tion zon
growth o
forefiel
by toe-f
of the d
The cy
process
the volu
sses. Th
gital te
To cha
the rati
lume ( P
were cai
Table 1 )
Table 1.
Period
May 7 8
July 78
April 79
August 7!
In the
a partici
volume o:
to 65 % 1
masses (<
data ref;
the dump«
cess of i
The chi
that the
The ini
also shoi
re procei
layer anc
tions ex:
The ini
cal condi
shapes oi
parable J
We can
has the l
strength
fore, foi
the toe-i
sive. The
content c
and multi
Howeve1
increase
caused b}
Interpi
has also
fluence c
ral envir
open surf
It was
wing down
netrate i
The wate
the flood
draining
Odra I'ive
by the ex
with the
morpholog