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