675 
Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986 
The study of mass movement from aerial photographs 
Varoujan Kh.Sissakian 
Geological Survey and Mineral Investigation, Baghdad, Iraq 
ABSTRACT: The applicability of large scale (1:5 000 and larger) aerial photographs in stu 
dying of mass movement is described. Their interpretation for different aspects, dealing 
with the mass movement like classification, prediction, recognition, dating and activity, is 
discussed and highly recommended in all projects, in which the land is involved. 
INTRODUCTION 
Mass movement is a term used for all kinds 
of movements which take place in rock and/or 
in soils on slopes due to one or more rea 
sons. The movement could be of different 
shape, size, origin, and type along one or 
more shear plane (then it is called land 
slide) or within thick zone consisting of a 
system of partial sliding planes (Zaruba & 
Mend 1969). 
Mass movements and landslides may cause 
huge damages to engineering works, proper 
ties, lives and human activities, due to 
these reasons many authors tried to classify 
the movements to different types. Among them 
are Heim 1882, Howe 1909, Almagia 1910, 
Terzaghi 1952, Ladd 1935, Shape 1938, Eme 
lyanova 1952, Varnes 1958, Eckel 1958, Ter- 
Stepainan 1966, Zaruba & Mencl 1969, and 
Nemcok et al. 1978 . 
These authors come to many classifications 
depending on different aspects like 
1. Form of sliding surface 
2. Kind of material moved 
3. Age of rate of movement 
4. Stage of development 
But still some difficulties occur in iden 
tifying the type of movement, because the 
type of movement does not depend only on the 
material in which it takes place, but also 
on the scale of the movement and also beca 
use "only in a few cases the movements occur 
in pure form" (Yague, 1978). 
Aerial photographs, especially of large 
scale 1:10 000 and larger can be used in 
studying different aspect of mass movements 
like their type, origin, causes, potentially 
critical areas, activity, and the prediction 
of the movement. From all of these, it is 
very neccessary to study aerial photographs 
of large scales before doing any engineering 
work or other activities in which the land 
is involved. Due to this it is always reco 
mmended, in large projects, to take inconsi 
deration the use of aerial photographs. Their 
use is recommended by (Zaruba & Mencl 1969, 
Harold <* Taliang 1978, Nossin 1978, Yague 
1978, Varnes 1976). 
1 CLASSIFICATION OF MASS MOVEMENT FROM AERIAL 
PHOTOGRAPHS 
In this study the classification of the mass 
movements is based on that followed by Nem 
cok et. al. 1978, these are: 
1.1 Slide 
Within this type are inclosed all those 
movements of coherent masses along one or 
more well defined shear surfaces. Two main 
kindes of slides can be recognized from 
aerial pnotographs, these are slides in 
rocks and slides in soils. These can be di 
fferentiated by recognizing: 
1. Where the scarpe is, i.e. in rocks or 
in soils. 
2. Whether the moved mass is rock or soil. 
3. The surrounding materials of the phe 
nomenon. 
Obviously the two kinds are very easily 
distinguishable on aerial photographs. 
1.2 Creep 
This type includes long-term movement of 
non-increasing velocity without a well de 
fined sliding surface. Zaruba & Mencl 1969 
confined this too. 
It is neccessary to mention that the creep 
process may lead to different types of mass 
movements if the creep is. accelerated due 
to any reason. The movement stops after rea 
ching equilibrium. Hence any recognized creep 
on old aerial photograph may be find as an 
other phenomenon during field check. 
Usually creep occur in soils, the toe area 
of which is associated mainly with small sl 
iding. Creep occurs in rocks too, but their 
recognition is very difficult. 
1.3 Flow 
This includes mass movements in rocks and 
soils analogous to the movements in liquids. 
Movements take place due to liquification 
due to any reason. According to Varnes 1978, 
some authors use the term creep for indica 
ting the flow. Zaruba & Mencl 1969 use di 
fferent terms for the flow like earth flow 
and debris flow. The most common movement 
of this type is the mud flow. 
1.4 Fall 
This is a sudden mass movement. The mooving 
mass looses its coherence and for a short 
time also its contact with the ground. The