Velingrad, October 21-25, 20061 WILL THE PRESENT-DAY SCIENTIFIC APPROACHES ENABLE TO FORECAST...

Velingrad, October 21-25, 2006Velingrad, October 21-25, 2006 11

WILL THE PRESENT-DAY WILL THE PRESENT-DAY SCIENTIFIC APPROACHES SCIENTIFIC APPROACHES

ENABLE TO FORECAST ENABLE TO FORECAST NATURAL DISASTERS?NATURAL DISASTERS?

Trahel VardanianTrahel VardanianYerevan State University, ArmeniaYerevan State University, Armenia


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.


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.

Today, man is unable to resist to Today, man is unable to resist to numerous natural disasters numerous natural disasters (earthquakes, floods and so on), of (earthquakes, floods and so on), of which he can become a victim any time. which he can become a victim any time. Science has developed thousands of Science has developed thousands of mathematical models of forecasting mathematical models of forecasting natural disasters, which, however, natural disasters, which, however, cannot: cannot:

• entirely explain the cause-and-effect entirely explain the cause-and-effect relations of phenomena, relations of phenomena,

• predict these phenomena, predict these phenomena,

• enable to withstand the expected enable to withstand the expected hazards. hazards.


The reason is that natural The reason is that natural phenomena are:phenomena are:

•multi-factoral,

• they have a complex mechanism, which is like a higher live organism,

• they cannot be managed by any science.


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.


Now we shall try to create a mathematical schematic model for forecasting some natural phenomena, as well as analyse its possibilities and setbacks.


formed in river basinsformed in river basins

conditioned by water flowconditioned by water flow

dangerous for society anddangerous for society and

environmentenvironment

They are overflowsThey are overflows..

Natural disasters and forming Natural disasters and forming them factors are diverse. them factors are diverse. However, we will introduce the However, we will introduce the ones which are:ones which are:


According to their origin, they can According to their origin, they can

be:be: downpourdownpour

flood (conditioned by snowmelt and ice flood (conditioned by snowmelt and ice melt)melt)

wind-induced surgewind-induced surge

ice-jam and ice-damice-jam and ice-dam

dammed and cut-offdammed and cut-off


Based on the international researches on the overflows, it became clear that the overflows occupy:

• the first place by the number of the first place by the number of emergence of natural disasters (about emergence of natural disasters (about 40% of all the disasters);40% of all the disasters);

• the second-third place by the number the second-third place by the number of casualty;of casualty;

• the first-third place by the degree of the first-third place by the degree of economic damage (billions of dollars).economic damage (billions of dollars).


In river basins, according to the In river basins, according to the degree of danger the overflows degree of danger the overflows may be:may be:

weakweak

averageaverage

strongstrong

disastrousdisastrous


The strong and disastrous overflows The strong and disastrous overflows emerge under the influence of two or more emerge under the influence of two or more factors (for instance, snowmelt + rainfall, factors (for instance, snowmelt + rainfall, downpour + dam destruction, etc.).downpour + dam destruction, etc.).

The downpour is the most widespread The downpour is the most widespread type of overflow. It can take place type of overflow. It can take place everywhere (except for Arctic and everywhere (except for Arctic and Antarctic), even in desert and semi-desert Antarctic), even in desert and semi-desert regions.regions.

Rain overflows are rather dangerous in Rain overflows are rather dangerous in mountainous dry, extreme continental mountainous dry, extreme continental climate regions. They considerably raise climate regions. They considerably raise the level of river water.the level of river water.


The causes of the emergence of The causes of the emergence of this type of overflows are:this type of overflows are:

• short-term and intense rains (the annual short-term and intense rains (the annual portion of water from the rainfall may portion of water from the rainfall may pour into river basins in single minutes)pour into river basins in single minutes)

• the geological structure of rock basin the geological structure of rock basin (90% of precipitation fallen on (90% of precipitation fallen on impermeable rocks form a flow)impermeable rocks form a flow)

• basin sizebasin size• the declivity of basin slopesthe declivity of basin slopes• the extent of vegetation cover of the basinthe extent of vegetation cover of the basin• the extent of basin dissectionthe extent of basin dissection• the anthropogenic factorthe anthropogenic factor• othersothers


Downpour overflows usually occupy small Downpour overflows usually occupy small drainage areas (up to 1000 km2) and are drainage areas (up to 1000 km2) and are particularly dangerous for towns and particularly dangerous for towns and rural areas. rural areas.

The threat is doubled due to the increase The threat is doubled due to the increase of the quantity of the hard sediment in of the quantity of the hard sediment in water and mudflow emergence. water and mudflow emergence.


• Today, having a powerful Today, having a powerful scientific- technical potential and scientific- technical potential and means, in particular, aerial space means, in particular, aerial space researches, photographing researches, photographing surveys, as well as geo-surveys, as well as geo-information system (GIS), man is information system (GIS), man is able not only to forecast but also able not only to forecast but also to prevent natural disasters.to prevent natural disasters.


All the factors which can cause flood formation and which we had discussed earlier can be classified into the following groups:

• climatic (C);climatic (C);

• physical (Ph);physical (Ph);

• biological (B);biological (B);

• geological (G);geological (G);

• chemical (Ch);chemical (Ch);

• anthropogenic (A) and others.anthropogenic (A) and others.


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.


Besides, if we establish a link between a natural disaster, in this case, flood (F) and influencing it factors:

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.

F = f (C; Ph; B; G; Ch; A; … n)


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.


ConclusionsConclusions

• It is necessary to form a It is necessary to form a synthesized sciencesynthesized science (Geography is (Geography is an example of such science),an example of such science), which would comprise all cause-which would comprise all cause-and-effect relations contributing and-effect relations contributing to forecasting of phenomena, and, to forecasting of phenomena, and, what is most important, would what is most important, would “enliven” the rigid mathematical “enliven” the rigid mathematical models used in studying these models used in studying these phenomena. phenomena.


• It is important to build a geo-It is important to build a geo-physical multi-factor physical multi-factor mathematical mathematical “live” model“live” model able able to operate. The model must have to operate. The model must have the following features:the following features:

• plasticity;plasticity;• flexibility;flexibility;• pulsation;pulsation;• reliability;reliability;• interrelation of links and feedback;interrelation of links and feedback;• cohesion with other models.cohesion with other models.

Solely in case of having these Solely in case of having these features the model will become features the model will become “live”.“live”.


• The model must be nourished The model must be nourished with the following information with the following information sources:sources:

manned satellites (geo-physical, climatic manned satellites (geo-physical, climatic data as well as maps and photographs)data as well as maps and photographs)

geo-information stationary observation geo-information stationary observation stations located on the Earth (data on stations located on the Earth (data on flow-forming and other factors and others)flow-forming and other factors and others)


• The model must work by means The model must work by means

of:of:

• data permanently received in the data permanently received in the geo-information systemgeo-information system

• differential series obtained from differential series obtained from the data and multi-factor links the data and multi-factor links formed between themformed between them


““Live” modelLive” model

Over flowOver flowX


The model must be very sensitive-to The model must be very sensitive-to be able to fix and analyze any slightest be able to fix and analyze any slightest change of any factor and possible change of any factor and possible consequences. consequences.

The model must be able to define The model must be able to define the factor or factors which for the the factor or factors which for the given time or space may be disastrous.given time or space may be disastrous.

This kind of models can be built This kind of models can be built not only for downpour overflows but not only for downpour overflows but also for any natural disaster (even for also for any natural disaster (even for earthquakes), with consideration of its earthquakes), with consideration of its peculiarities. peculiarities.


These models can give the These models can give the opportunity to forecast disasters opportunity to forecast disasters and undertake necessary means and undertake necessary means for their prevention.for their prevention.

• Any region must have its Any region must have its characteristic model, each of which characteristic model, each of which can be different, if not divergent. can be different, if not divergent.

Thank you for attentionThank you for attention

Contact address:Contact address:Department of Physical Department of Physical Geography,Geography,Yerevan State University, Yerevan State University, 1, Alek Manoukian Street, 1, Alek Manoukian Street, Yerevan,Yerevan,0025, Republic of Armenia0025, Republic of ArmeniaFax: (374-10) 55-46-41Fax: (374-10) 55-46-41Email: Email: [email protected]@ysu.am

Velingrad, October 21-25, 20061 WILL THE PRESENT-DAY SCIENTIFIC APPROACHES ENABLE TO FORECAST...

Documents

Transcript of Velingrad, October 21-25, 20061 WILL THE PRESENT-DAY SCIENTIFIC APPROACHES ENABLE TO FORECAST...