Disasters can be predicted
Photo by Vasyl Kyyashko
People suffer from floods because they fail to consider the natural
peculiarities of the region.
This year people suffered over 80 mln hrn in flood damage in the
Transcarpathians. Snyatynskyy region alone needs 5 mln hrn to fully clear damage
from the flood and fix the houses and farms.
Neighboring Chernivtsi oblast suffered flood damage estimated at 32 mln hrn. The
floods ruined river streams, washed away and damaged bridges, and flooded
people’s houses and farms.
Can such horrible from flood damage be predicted by scientists? We referred to
Olha Kynal, head of the physical geography and rational nature use
department, Chernivtsi National University.
(Continued on Page 4)
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Disasters can be predicted
Catastrophic floods can happen every 27-30 years
Olha Kynal, head of the physical geography and rational
nature use department, Chernivtsi National University
Hutsuly passed the information about floods from generation to
generation
- Can we predict floods with the help of science?
- The Transcarpathian region has its own peculiarities that have to be considered
all of the time when making predictions about new floods. When there is a lot of
rain in the mountains, the water, after flowing through narrow mountain river
streams, flows into bigger rivers with great speed. The water comes in a flooding
wave, like a wall, and as soon as it hits a plain, it floods it – if it is strong enough, it
goes beyond the banks. Mountain rivers are fed by numerous little tributaries that
very quickly fill up the main stream.
This has always happened and will continue happening. Human life,
however, is much shorter than the duration of the disaster cycle. These big floods
that happened in Europe in the 90s are repeated every 200-300 years and this has
been noted in written documents. Everybody just forgot about the big floods that
hit Czechoslovakia, Poland, and Germany. Less catastrophic floods hit every 20-30
years and there are also floods that repeat each 100 years or more.
- How often should we expect floods in our region?
- It has been noted that the cycle repeats every 30 years, but the repetition is not as
strict because the natural cycle is also affected and changes a couple of years back
and forth. The rainfall statistics on a time scale show that in the southeastern part
of the Transcarpathians the catastrophic floods happen once every 27-30 years.
Every 6-7 years, extensive rainfalls in June & July are possible, which also causes
floods like this year.
- Does the damage from human activity also cause disasters to come?
- Hydroclimate processes have a big influence on the surface – erosion, river
directional changes, appearance of landslides, land getting washed away, and the
formation of mountain slopes. There is a common opinion that the main reason for
floods is forest clearing in the mountains. They say that before forest clearing,
there were no floods. In fact, floods did happen. Forest clearing is not the only
reason – it’s just a supplementary one. Woods do perform the function of
controlling river flows. The roots of a well-developed 30-40 year old tree on a
mountain slope can control 1 ton of water. Waterfalls from a slope covered with
wood flow down must slower than from a “bald” slope, which shortens the time it
takes to create a flood. This also concerns gravel theft from the river banks. Often
times, it is the reason river banks get washed away. Moreover, if the forests are cut
from the mountains, all that is left afterward is remnants and branches, which is
washed by the water into the main river. Therefore, large obstructions are created
near bridges, so the water hits the poles and the bridge is ruined.
A flood wave can go a couple dozen kilometers in one hour. This is a current
that cannot be stopped and it washes everything in its way. The danger of the
floods in this district is that they are not necessarily formed along the entire river –
a flood can happen even in the upper river. At that time, in the lower river, the
water will be calm and weather will be sunny but because of the rainfall on the top
of the mountain, the flood will cover the whole plain. Right now the floods have
become especially dangerous because people have forgotten that it is dangerous to
settle above the water-meadow. In the 50s and 60s, the scientists went around to the
oldest people in the Carpathians to gather information about the floods. One of the
ways to predict floods is to mark the water level – marking the highest point that
the water reached during the flood. One old Hutsul says, “Oh, the water reached
this church. Even my grandfather told me about it.” Can you imagine that? Even
his grandfather told him about it. People remembered such information and never
settled in lower than that level. They passed the information from generation to
generation because for some people, it was a matter of life and death. People
would not settle in the Transcarpathian regions that were flooded often. During
Austrian rule, dams were built here. Soon these dams were taken apart and plains
were populated. Now people suffer damage and they have to be reimbursed.
In order to predict disasters we need scientists and money
- How can we predict a flood in order to have enough time to prepare for it?
- It is definitely possible to predict a flood; we can predict strong cyclones that are
moving toward us. There are ways of hydrological observation. We can install
recording equipment on mountain rivers that measure the water level. It doesn’t
take scientists, but even clever people can watch them: teachers, village
administration secretary or just a smart guy. The main task is to come everyday
and note the level to which the water in the river has risen. Then, when the rain
falls, one can see how fast this level increased. If the mark reaches a certain point,
one must immediately call somebody in the plain: to the hydrometeorologicalcenter in the region or oblast. If such calls or messages come from a couple of
different points, people in the plains
should start preparing for a flood.
They must use all possible
measures to decrease the damage and
consequences from the disaster. It is
very important for predictions to
broaden the net of observation points.
This is why we need to have a lot of
meteorological points and stations in
each problematic region.
Of course, to create such a
network it takes money and special
state programs to support it. In order
to control the flooding process in the region, the authorities must involve scientists
and practitioners to perform scientific soil analysis on the development of natural
processes in the region. The tests have to not only be on the rainfall, but also on
erosion, karst processes and changes in stream direction. Then we can compile
scientific recommendations according to which we will be able to predict the speed
at which all of the above processes Extensive rainfall that happened this
develop. For such research, we will summer can be repeated, according to
need
information
from
the scientific predictions, in another 6-7 years.
hydrometeorological center. We
cannot get it for free, but the authorities do have access to it. We have very
qualified scientists, but do not have enough information for scientific expertise.
Having learned the natural conditions in detail, a scientist can conclude whether or
not one can build housing on a given territory, put in a pipeline or anything else.
We need a complex map of the region, which would reflect all the complexity of
natural conditions and level of danger for disasters in particular regions. Each
community would make good use of such a map and the city head would always
know about the land that is dangerous for any activity. If everything above is done
and considered, we can avoid big losses and damages from natural disasters.
This publication is supported by the Investigative Journalism Project in Ukraine
(SCOOP), the Danish Association of Investigative Journalists (FUJ), and the
Ministry of Foreign Affairs of the Kingdom of Denmark.
Viktor Dudar