PHOTO-GEOMORPHIC CLUE TO DETECTION OF LANDSLIDE-PRONE
SLOPES, DRAWN FROM NOTABLE DISASTERS IN
JAPAN
Seiichi HATANO,
OYAGI,
Norio
*
Institute,
Construction, Kitazato, Tsukuba
National Research Center for Disaster Prevention, Science and
Tennodai, Tsukuba
Commission VII
ABSTRACT
We studied causal conditions for 25 cases selected
disasterous landslides in
, us
preslide
There are many factors controll
stabil
But,
any landslide, individual
up to sl
must be different from those of its
'stable'
and from those of the same site considerable
time before
An
is of these differential conditions peculiar to
ide
is named va
ime
of
instabil
To actualize this analysis,
the fol
: (1) modell
ion for
instabil
index; (2) differentiat
manifold s
ficance of 'land form' for
instabil
(3) comparative
evaluation of the
variables in terms of kind,
intensi
; and (4)
of multidate ai
and cross-check with other information.
A conclusive cross-table, with
types
and recent destabiliz
variables,
the 25
cases
with some other
grades for each site class.
Key Words: Landslide,
genesis,
ime
morphoMulti-date airphotos,
CONTENTS
1.
Introduction
2.
Exist
methods for landslide
2.1 Mechanical stabil
2.2 Statistical multivariate
3.
The
3.1
3.2
3.3
3.4
4.
ive
instabil
ficance of 'land form'
for
instabil
Utilization of multi-date airphotos
ive evaluation of proximate inducing variables
Case studies on the 25 disasterous landslides
4.1 Selection of cases
*
The full paper (booklet) is
this v
with
4.2
4.3
4.4
4.5
4.6
4.7
Data collection
Procedure of inductive
is
Outline of the 25 disasterous landslides
Basic
of the landslide source areas
is of the causal conditions before sl
and
in its time, site and extent
Relat
between
variables and
site conditions of landslides
4.8
to detection
ic
5.
5.2
5.3
5.4
landsl
and recent
variables
Influences of
destabiliz
variables
Possibil
of more effective use of ai~~n~,~
Recommendation to
hill
behind dwell
new leaves
remarks
6.
References
TABLES
1.
Comparison of three methods for
slope instabil
2.
Comparison of some di
landslide source area
of landslides and
estimates of the size of a
3A. Overview of the 25 landslides and their disasters
3B.
and
the 25 cases
~rnn,aT'~ies
of landslide source
4.
Relationship between proximate inducing variables and site
conditions of the 25 landslides
5.
Geomorphic clue to detection of landsl
slopes
FIGURES
1.
Procedure of 'a
ime
ive
slides and their causal conditions
2.
Distribution of the 25 disasterous landslides
3.
Identification of landslide source area and major division
of a whole landslide area
is' of land-
PHOTOGRAPHS
of
the 25 sites before
sl~~Lu.~