Download Will the Present-day Scientific Approaches Enable to Forecast

WILL THE PRESENT-DAY
SCIENTIFIC APPROACHES
ENABLE TO FORECAST
NATURAL DISASTERS?
Trahel Vardanian
Yerevan State University, Armenia
Velingrad, October 21-25, 2006
1
In the age of present-day scientific
and technical achievements, man’s
safety does not seem to be ensured.
In particular, it refers to the process
of forecasting and managing natural
phenomena.
Velingrad, October 21-25, 2006
2
The end of XX century and the
beginning of XXI century are
distinguished by the abrupt growth
of natural phenomena. In this
respect, in the recent decades NATO
and UN have developed a number of
projects and activities, aimed at the
possible forecasting of natural
phenomena, danger alleviation, as
well as removal of consequences.
Velingrad, October 21-25, 2006
3
Today, man is unable to resist to numerous
natural disasters (earthquakes, floods and
so on), of which he can become a victim any
time. Science has developed thousands of
mathematical models of forecasting natural
disasters, which, however, cannot:
• entirely explain the cause-and-effect
•
•
relations of phenomena,
predict these phenomena,
enable to withstand the expected
hazards.
The reason is that natural phenomena
are:
• multi-factoral,
• they have a complex mechanism, which is
like a higher live organism,
• they cannot be managed by any science.
Velingrad, October 21-25, 2006
5
Thus, mathematics cannot forecast
these phenomena with its “dead”
models, which can be fatal for man.
Yet, mathematics has “managed” to
make phenomena prediction rigid
and bring them to forecasting field,
and, by this, to assist to arrive at
some solution of this issue.
Velingrad, October 21-25, 2006
6
Now we shall try to create a
mathematical schematic model for
forecasting some natural
phenomena, as well as analyse its
possibilities and setbacks.
Velingrad, October 21-25, 2006
7
Natural disasters and forming them
factors are diverse. However, we will
introduce the ones which are:
 formed in river basins
 conditioned by water flow
 dangerous for society and
environment
Velingrad, October
They are overflows
. 21-25, 2006
8
According to their origin, they can be:
 downpour
 flood (conditioned by snowmelt and ice melt)
 wind-induced surge
 ice-jam and ice-dam
 dammed and cut-off
Velingrad, October 21-25, 2006
9
Based on the international researches
on the overflows, it became clear that
the overflows occupy:
• the first place by the number of
emergence of natural disasters (about
40% of all the disasters);
• the second-third place by the number of
casualty;
• the first-third place by the degree of
economic damage (billions of dollars).
Velingrad, October 21-25, 2006
10
In river basins, according to the degree
of danger the overflows may be:
 weak
 average
 strong
 disastrous
Velingrad, October 21-25, 2006
11
The strong and disastrous overflows
emerge under the influence of two or more
factors (for instance, snowmelt + rainfall,
downpour + dam destruction, etc.).
The downpour is the most widespread
type of overflow. It can take place
everywhere (except for Arctic and
Antarctic), even in desert and semi-desert
regions.
Rain overflows are rather dangerous in
mountainous dry, extreme continental
climate regions. They considerably raise
the level of river water.
Velingrad, October 21-25, 2006
12
The causes of the emergence of this
type of overflows are:
• short-term and intense rains (the annual
•
•
•
•
•
•
•
portion of water from the rainfall may pour into
river basins in single minutes)
the geological structure of rock basin (90% of
precipitation fallen on impermeable rocks form
a flow)
basin size
the declivity of basin slopes
the extent of vegetation cover of the basin
the extent of basin dissection
the anthropogenic factor
others
Velingrad, October 21-25, 2006
13
Downpour overflows usually occupy small
drainage areas (up to 1000 km2) and are
particularly dangerous for towns and rural
areas.
The threat is doubled due to the increase of the
quantity of the hard sediment in water and
mudflow emergence.
Velingrad, October 21-25, 2006
14
• Today, having a powerful scientific-
technical potential and means, in
particular, aerial space researches,
photographing surveys, as well as
geo-information system (GIS), man
is able not only to forecast but also to
prevent natural disasters.
Velingrad, October 21-25, 2006
15
All the factors which can cause flood
formation and which we had discussed
earlier can be classified into the following
groups:
•
•
•
•
•
•
climatic (C);
physical (Ph);
biological (B);
geological (G);
chemical (Ch);
anthropogenic (A) and others.
Velingrad, October 21-25, 2006
16
These groups of factors are connected
to one another by multifunctional
mathematical links, i.e., they are to
have numeric ranges, which are not
always present or reliable.
Velingrad, October 21-25, 2006
17
Besides, if we establish a link between
a natural disaster, in this case, flood
(F) and influencing it factors:
F = f (C; Ph; B; G; Ch; A; … n)
Then, at the first sight it seems as if
the presence of many factors will
reveal the essence of the phenomenon,
will raise the degree of reliability of
forecasting this disaster.
Velingrad, October 21-25, 2006
18
That is so, the more factors are observed,
the better the revelation will be.
That is theoretically true.
However, in practice, when the link
between these factors is expressed in
mathematical terms, then the
correlation coefficient of this link
becomes smaller, which means
decrease of the degree of reliability. It
means, that the language of
mathematics is rigid.
Velingrad, October 21-25, 2006
19
Conclusions
• It is necessary to form a synthesized
science (Geography is an example of
such science), which would comprise
all cause-and-effect relations
contributing to forecasting of
phenomena, and, what is most
important, would “enliven” the rigid
mathematical models used in studying
these phenomena.
Velingrad, October 21-25, 2006
20
• It is important to build a geo-physical
multi-factor mathematical “live”
model able to operate. The model
must have the following features:
•
•
•
•
•
•
plasticity;
flexibility;
pulsation;
reliability;
interrelation of links and feedback;
cohesion with other models.
Solely in case of having these features
the model will become “live”.
Velingrad, October 21-25, 2006
21
•
The model must be nourished with
the following information sources:
 manned satellites (geo-physical, climatic
data as well as maps and photographs)
geo-information stationary observation
stations located on the Earth (data on
flow-forming and other factors and others)
Velingrad, October 21-25, 2006
22
• The model must work by means of:
• data permanently received in the geoinformation system
• differential series obtained from the
data and multi-factor links formed
between them
Velingrad, October 21-25, 2006
23
“Live” model
X
Over
flow
Velingrad, October 21-25, 2006
24
The model must be very sensitive-to be
able to fix and analyze any slightest
change of any factor and possible
consequences.

The model must be able to define the
factor or factors which for the given time
or space may be disastrous.

This kind of models can be built not
only for downpour overflows but also for
any natural disaster (even for
earthquakes), with consideration of its
peculiarities.
Velingrad, October 21-25, 2006
25
• Any region must have its
characteristic model, each of which
can be different, if not divergent.
These models can give the opportunity
to forecast disasters and undertake
necessary means for their prevention.
Velingrad, October 21-25, 2006
26
Thank you for attention
Contact address:
Department of Physical Geography,
Yerevan State University,
1, Alek Manoukian Street, Yerevan,
0025, Republic of Armenia
Fax: (374-10) 55-46-41
Email: [email protected]