Contents


Flood forecasting system
in the Czech Republic

 

 

lessons learned from floods over the past few years have
induced all those involved in flood protection in the Czech Republic to review the country‘s existing flood protection system and create measures to improve its operation

 

 

The lessons learned from floods over the past few years have induced all those involved in flood protection in the Czech Republic to review the country‘s existing flood protection system and create measures to improve its operation. The implementation of improved measures was supported by Decree No.185/1998 of the Czech Government and by a number of national and international projects.
Along the same lines, the Czech Hydrometeorological Institute, CHMI, has reviewed its flood forecast service and designed a set of measures for its improvement which - finances permitting – will be gradually implemented in the areas of meteorology, hydrology, dissemination of information and forecasts.

Credits: Archive

 

Precipitation forecasting

 

For operative information about precipitation, CHMI relies on:
• automatic collection of data from the system of reporting stations, and the supplement of the network according to the need of entries into hydrological models, especially in the mountainous regions;
• information from meteorological radars. With the recently built radars in Moravia and another one in central Bohemia, the radar system is now complete. A system of ongoing calibration of radar information about fallen precipitation is being developed and gradually implemented;
• outputs of numerical models operated by the meteorological services of some European countries and ALADIN regional model, which is computed in Prague;
• information produced by the European Centre for Medium-Range Weather Forecast based in Reading, U.K., which produces the forecast of meteorological elements including precipitation for 10 days ahead. CHMI gained access to these data in 2001.

 

Discharges and flood forecasting

 

For information on discharges and flood forecasting, CHMI depends on:
• its own and the catchment companies‘ current reporting watergauging network, which is sufficient for flood forecasting on the main streams and only in some regions will need to be supplemented;
• automatic collection of data from watergauging stations, which is currently being carried out by several transmission systems both at CHMI and the catchment companies;
• hydrological forecasting models calibrated for all main streams in the Czech Republic. In the year 2001 the models were experimentally operated daily by CHMI forecasters and as a standard produce forecast for 48 hours in advance.
CHMI’s central forecasting unit disseminates information to flood institutions and other national and regional-level users (including catchment companies), and the regional forecasting units do the same at the level of districts and large cities. After the large floods of the 1990s, the system of flood reporting service was overhauled by the Ministry of the Environment. It is now necessary to update the flood forecasting service.
Due to its simplicity, the usual way of expressing the extent of flood danger in degrees of flood activity is suitable for all levels of flood service. The legislative basis for flood forecasting and reporting service is provided by the new Water Law which ensures availability of information for flood institutions, crisis management institutions and the integrated rescue system. Although the relationship between flood institutions and institutions of crisis management is regulated by the relevant laws, the efficiency of the system has yet to prove itself in future large floods.

 

Evaluation of the response to August 2002 flood

 

Throughout the flood of August 2002, both CHMI’s meteorologists and hydrologists were busy preparing reports and forecasts for decision-taking bodies and the general public and supporting the rescue system. Overall, the flood protection and rescue system worked very well and many protective measures were carried out during the flood including the evacuation of people. In comparison, the system proved to be more effective than it was during the previous catastrophic flood in Moravia in 1997. Apparently, the experience gained from the flood in Moravia and the subsequent adoption of new laws about crisis management and the integrated rescue system (IRS) had a positive impact on institutional response to the flood of August 2002.
Crises management and IRS were functioning in the Czech Republic for the first time. Following a timely declaration of a state of emergency by the prime minister, the central crises management body swung into action and efficiently dealt with most problems by heavily relying on meteorological and hydrological information provided by CHMI. Regional crises bodies also worked very well with the exception of some problems in Prague. The projects for the research, development and application of modern methods to forecasting (in the case of CHMI the development of meteorological and hydrological modelling) should be supported by the government and so should a modernisation of the monitoring networks. Crises management laws in general should also be upgraded.


Author: Eva Soukalová
Further information: www.chmi.cz