Upgrade and development of flood alarm and forecast model of MURA

The scope of the project is the flood plain and foreshore of the river Mura that is the 48 km long section of Hungarian and Croatian common interest of the River Mura. Flood effects and risks along this section inseparably affect both areas and thus trigger a need for close cooperation in protection activities. Austria, Slovenia, Croatia and Hungary developed the international flood alarm and forecasting system in 2011 for the whole catchment area of the Mura. All countries participate in operation and maintenance of the system, which has been operational for 7,5 years, by supplying their own real-time data and by continuously monitoring and evaluating the complete system. This project aims at renewing and further developing this system on the HR-HU section of common interest of the Mura by upgrading the existing 1D forecast model with the latest data and further developing it by the use of stateof-the-art technology. The innovative content of the development is that, based on different meteorological forecasts (ensemble technology), different flood forecasts are prepared instead of the currently existing one. Temporary changes of the roughness of the flood plain, which significantly modify flood propagation, are also taken into consideration. Thus, with the 20-25 versions of forecast a more accurate picture showing the probability of the occurrence of expected flood events and more reliable forecasts are achieved. Compared to the previous model, a step forward is the ability to provide water level data at 4 new points of the flood plain (data assimilation) in order to achieve more exact forecast. The development is carried out within the state-of-the-art 1D modelling system, the developed model will then be integrated into the a new and modern forecast framework through which data processing, operation and access to data will be simplified. The development is carried out under close cooperation with Austria and Slovenia with respect to harmonising ongoing parallel developments and integrating model-parts. The overall objective is to develop efficient and real-time flood cooperation between Hungarian and Croatian bodies involved in flood protection. Flood risk assessment is greatly facilitated by joint and cross-border cooperation of the competent institutions (HU, HR), since the cross-border flood forecast model provides quick access to relevant information about the complete section of the Mura. Thus, developments are utilised by flood protection organisations and stakeholders and residents in areas at risk of flood on both side. The specific objective is to renew the existing Mura forecast model and to further develop it by means of ensemble forecasts and high-water river data assimilation on the joint section of the Mura and the areas that affect it. The direct target groups include flood protection organisations (HU, HR) and hydrographic services. Those indirectly affected are Hungarian and Croatian residents living in the area endangered and municipalities. Those further affected are stakeholders living in the area, a national park, waterworks suppliers, and the Hungarian Public Road KHT. Expected results: - Developed HU- HR flood management cooperation. - More accurate forecast of flood information. - A website in two languages to provide access to results. - Events and workshops to provide information about the project results. - A joint forecast simulation practice to practise joint usage of the new model. The results will be serviceable and accessible in the long term, similarly to the current system. The project forms an integral part of the flood alarm and forecast system of the Mura designed in 2011 and also the ongoing development work abroad. Project partners jointly carry out work and coordinate operation. In order to develop the model, data from the latest geodetic surveys conducted within the HAMURA project, the Mura High-Water Riverbed Management Plan and the already completed 2D flood results will be used.

The area the project focused on is the 48 km long border stretch on the Mura river, shared by the two countries. There is often flooding on this section and the water has caused significant damage on both sides in the past, this is why the partners came together to strengthen the cooperation between the water management authorities in order to minimize the potential damage to people and property. During the project the flood forecasting model, developed more than a decade ago by the four countries affected by it (Austria, Hungary, Slovenia and Croatia) has been upgraded by the freshest data, collected by the newly installed equipment in order to raise the level of preparedness in the Hungary-Croatia border section.