High School Brno-Lisen, High School Brague-Vitezna Plan, Elementary School Liskovec, DDM Valasske Mezirici

Essay on natural disasters. Students: Eva Krajova, Lucie Stastova, Ludvik Hasal, Petr Podzemny, Mirek Tichy
Teachers: Jitka Dvorska, Lucie Zacharnikova

Time-edition: 1999


The presentation of „Big water in our small country" wants to show to the rest of the world the natural disaster which appeared in the Czech Republic in July 1997.

At the beginning of the presentation we show short TV shot which helps to imagine what was happening in those days.

Natural disasters cause big troubles to mankind. As many other ecological problems, we can help to avoid then or be ready and protected, only if we understand nature and how our actions effect it. In July 1997, a period of extraordinary continuous regional precipitation occurred on territory of the Czech Republic, especially in Moravia, Silesia and eastern Bohemia and caused floods with extraordinary impacts - big material damages (2 billion US dollars) and death of nearly 50 people (the fig. 1 shows territory affected by floods - almost one third of the Czech Republic, similar floods appeared at that time in Poland).

Daily rainfall during period 4 th - 8 th of July was sometimes as high as 234 mm (Lysa hora Mt., 6 th to 7 th of July) and the 4 days record 602 mm. Sance st). This is much greater rainfall than is usually measured in the capital city of Prague in the whole year. Rivers of Moravia could not take this amount of water and the flood wave was taking everything standing in its way. (The fig. 2 and 3 show the flow of flood waves on the rivers Becva and Morava).

Our Globe schools kept obtaining their data even during this hard time. On Presented graphs the rainfall for July is shown ( taken by Globe schools ZS Banov, ZS Vitkov, ISS Valasske Mezirici, DDM Valasske Mezirici (fig.4) and SPS Otrokovice). Their data correspondent with official measurements of Hydrological Institute. Always there is an extreme peak in the first third of July )or an other one at the and of July). The maximum of daily rainfall reaches here some 40, 85, 165, 160 mm. Some data are missing (SPS Otrokovice, 11. 7. - 27. 7. ) because the measuring sites were at that time under the water.

The proceeding of the floods can be seen from satellite pictures taken during that time. As well they correspond with maps obtained from Globe schools data. Globe students took many pictures of flooded areas.

Floods affected also our study sites for biometry and phenology - pixels. DDM Valasske Mezirici (pixel has code 0231 MUC classification) reports changes in canopy and ground cover (before floods being 94 % and 87 %, month after flood both 0 %, a year after 94 % and 21 %) and changes in species variability. Other schools report similar data (SPS Otrokovice - before flood canopy cover 84 % and ground cover 70 %, month after 68 % and 24 %, a year after 63 % and 67 %).

It was as well proved that the floods haven’t had only negative sides. In the view of ecologists it had revitalised the rivers ecosystem, allowed breeding of some endangered bird species and helped some fish species move with the water to new territories.

Though, most of the effects were disastrous and can be compared to the war front passage. Big floods cannot be avoided. But it is posible to have a better protection and thus reduce the danger and losses. Our Globe students can to contribute to that by providing data from their sites and understanding what happens with nature around them.