Hungary is particularly vulnerable to flooding compared to other European countries, largely due to its geographical and hydrological characteristics. Since the turn of the millennium, in a row, on our rivers have exceeded the highest flood water levels and the flood protection tasks meant an extraordinary challenge for the country and for the water management sector in their protection tasks. As a direct effect of climate change, the hydrological hazards have become more extreme and less predictable and therefore the preparedness, strengthening the effectiveness of response capacity and the enforcement of the “room for the rivers” principle gets more attention as before, in one word, on improving the conditions of flood conveyance.
In line with the increasing risks, the flood protection activities, the extraordinary efforts and the preparedness using traditional methods are such a burden on the budget and it has become to improve the early warning and forecasting systems, to focus on adaptive, preventive solutions and to use of modern, IT-based water management systems and operational decision support services. All these not only increase the efficiency of protection tasks but also enable the water management sector to implement its flood prevention improvements and measures in a prioritized and optimized manner.
Flood risk in Hungary
On one hand, flood risk and hazard mapping provides information on the areas of the country at risk of flooding and on the other hand, it helps, to estimate the magnitude and nature of risks that floods pose to local residents and the Hungarian budget. The hazard maps have been prepared using different numerical modelling methods to determine the areas at risk and the degree of vulnerability for each type of flooding.
The results show the spatial extent of the endangered areas by potential flood events in a pre-checking way nationally, by planning area unit and by planning sub-area. In the frame of the “KEHOP” project (No. 1.1.0-15-2016-00006), entitled “Preliminary flood risk assessment, hazard and risk maps, first revision of risk management plans”, the first revision of flood risk management plans were completed in 2022.
The completed documents and the detailed information are available at the following link: https://vizeink.hu/akk-elso-felulvizsgalata/
Temporary flood protection dike - heightening flood protection levees – protection against flood which exceed the dike crest
Examination of flooding from possible breaches of flood protection embankments – updating localization plans
In the context of the national flood hazard and risk mapping and strategic planning programme, an up-to-date localization plan of 73 flood plain areas covering almost a third of the country has been prepared, which provides information for alert, rescue, evacuation plans locals in case of a possible overtopping or dike breach.
According to the rules of protection against water damage determined under (1) section b) of 8 Article in the Government Decree no. 232/1996. (XII. 26.), entitled “Regulations about people obliged to protect against any water related damages and causing damages to waters”, the so-called localization plans must be prepared.
The localization plans should include all documents, data, records and other plans necessary for effective flood protection. Digital simulations were used to examined the spread and the depth of inundation, , the water flow velocity generated and the time taken to reach the populated areas or the rescue routes from the moment of the beginning of a dike breach (temporal and spatial of flooding).
The aim of all of these is to intervene immediately in case of a potential dike breach, in order to minimalize the damages caused by flooding and to protect the inhabitants.
The flood protection tasks
The purpose of flood protection is to maintain and improve the flood protection structures owned by the State and to carry out protection tasks on them. The flood defence actions can be divided into two, well separated groups. One of them focuses on the technical tasks of flood protection and the other one focuses on the arrangements, governance and performance of the administrative tasks.
The concept of flood safety varies in space and time, but also depends to a large extent on the stage of development and rate of tolerance of the individuals and the communities. In order for safety to be manageable (quantifiable, plannable, considerable), the first and the most important aspect is to formulate flood safety policy of flood protection security on the appropriate level. The declaration of the safety policy is a governmental task, which is implemented through institutional, regulatory and the budgetary means. On one hand, the technical side of safety is carried out by standards, technical guidelines and on the other hand, by regulations, which laying down methodological and procedural rules.
Forrás: Dr. Szlávik L, Tóth S., Nagy L., és Szél S., - Árvízi kockázatok elemzésének és térképezésnek irányelvei / Vízügyi Közlemények 2002. / 4
Source: Principles of examination and mapping of flood risks from the magazine called Water related Announcements, issue 4, year 2022 by Dr. Szlávik L, Tóth S., Nagy L., és Szél S., (Original titles: Árvízi kockázatok elemzésének és térképezésnek irányelvei / Vízügyi Közlemények 2002. / 4
Methods to prevent flood damage
In flood damage prevention – also known as flood management – we differentiate structural and non-structural flood protection measures. The extremes of flow regimes make it increasingly necessary to focus on the latter category.
Methods of structural measurements:
- Heightening the dikes according to the regulations
- Relocation of dikes to improve thereby increasing and improving the flood conveyance capacity of the floodplains
- Reducing the filling of flood plains by dredging, removing belt shaped sandbanks, increasing the channel capacity of flood plains
- Riverbank management and regulation, bank protection, proper maintenance of water regulatory structures
- Construction of emergency reservoirs and spillways
- Dredging the tributaries, revitalization and rehabilitation of tributaries and oxbows,
- Removing “summer dikes” from the floodplains
Methods of non-structural measurements:
- Changing and optimization of cultivation.
- Regulating the use of floodplains and riverbeds (land use restrictions, building bans and preferences)
- Flood hazard and risk mapping
- Preparation and raising awareness.
Checking the structures
In order to maintain adequate protection capacity, it is necessary and a legal obligation to carry out an annual review of the works under the management of the local water directorates.
According to the Article 6, (1) d) of KHVM regulation no. 10/1997 (VII. 17.), titled “Water directorates responsible for and carrying out flood and inland water protection” and the Article 8, (1) of Decree of the Government no. 232/1996. (XII. 26.), titled „ Rules for protection against water damage”, the annual inspections of the protection structures shall be carried out in the autumn period.
The purpose of the inspection is to review the preparations for floods and excess water protection. A report is prepared about the review, in which the findings are recorded by every protection section and covering the entire scope of the review. Measurement plans are prepared to remedy the shortcomings and deficiencies identified during the review.
National Technical Coordinating Body
In case of the protection tasks intensify and a national-wise coordination is needed (level III alert, or simultaneous protection by several water directorate or local water damage control covering parts of the country), the National Technical Body is set up.
The Chief of the Body is responsible for the tasks of OMIT
The leader of the regional water directorate, makes his proposal for the declaration of an emergency to the Minister through the Head of OMIT.
During the defence period, OMIT works 24-hour shifts, and maintains a technical standby service on weekends and public holidays.
National control of protection is exercised by the Minister through the Chief of Body in any flood protection or excess water section, for areas of water scarcity, protection preparedness ordered during an intervention in connection with ice protection or water quality damage, and the ordered interventions related to water quality prevention and in the local water damage control preparedness of the local water directorates’ standby.
Within the OMIT, there are different specialised expert groups, which operate and are responsible for a specific type of task. The OMIT consists of the Chief of Body, his/her Deputies, the technical 24/7 service, the Central Standby Service and their subordinated expert groups being responsible for technical issues and suppliance.
OMIT is the national technical lead and the decision support in all water damage and water quality protection situations:
- it nationally aggregate the data on protection activities, documents and evaluates the protection situations, prepares daily protection reports, other reports and briefings;
- supervises the activities of the territorially competent water directorates, the defence staff of Budapest and the Major is responsible for municipal flood protection activities through the local defence chief,
- it decides on technical, water related issues affecting more than one water directorates’ territories or parts of the whole country or gives orders for inventions in the frame of its own competency or for the local protection leader’s suggestion (including the Lord Major of Budapest),
- it coordinates the national human resources and it allows to carry out measurements or order resource-related measurements on its own competency or on the local protection chief’s proposal,
- it operates expert groups or involves other external resources to prepare decisions at national level;
- it provides information on protection national-wide.