Preliminary Flood Risk Assessment in Relation to The Project of Flood Directive Marcin Jacewicz Regional Board for Water Management in Gdańsk

Introduction EU Flood Directive – flood risk management EU Flood Directive – flood risk management Conscious, planned decision making process for the purpose of flood risk decrease Conscious, planned decision making process for the purpose of flood risk decrease GIS – Geographic Information System – the tool for the analysis GIS – Geographic Information System – the tool for the analysis Flood Risk Maps Flood Risk Maps EXCIMAP (European exchange circle on flood mapping) to elaborate guide of good practices of flood mapping in Europe EXCIMAP (European exchange circle on flood mapping) to elaborate guide of good practices of flood mapping in Europe

Three Steps of Work Preliminary flood risk assessment maps Preliminary flood risk assessment maps Flood hazard maps Flood hazard maps Flood risk maps. Flood risk maps.

Preliminary flood risk assessment First step – three years First step – three years Objective – to indicate flood risk areas where further steps will be taken Objective – to indicate flood risk areas where further steps will be taken „Flood risk is the combination of the probability of a flood event and of the potential adverse consequences to human health, the environment and economic activity associated with a flood” (Flood Directive) „Flood risk is the combination of the probability of a flood event and of the potential adverse consequences to human health, the environment and economic activity associated with a flood” (Flood Directive)

Questions How to indicate flood risk areas? How to indicate flood risk areas? What information do we have? What information do we have? How can we collect dispersed information? How can we collect dispersed information? How to evaluate risk? How to evaluate risk? Who will do it? Who will do it? How much time do we have? How much time do we have? How much it will cost? How much it will cost?

How to indicate flood risk areas? Indicated areas will be further the subject of expensive studies for hazard and then risk maps elaboration Indicated areas will be further the subject of expensive studies for hazard and then risk maps elaboration Not indicated areas may implicate consequences of unexpected risk and flood impact to this areas Not indicated areas may implicate consequences of unexpected risk and flood impact to this areas Analysis shall consider cost and available time of preparation (3 years) Analysis shall consider cost and available time of preparation (3 years) We have to collect as much as possible of existing data and then make a decision where the risk is high, medium and low We have to collect as much as possible of existing data and then make a decision where the risk is high, medium and low

What information do we have? Information about historical floods Information about historical floods Studies for flood protection Studies for flood protection Archives Archives Long term prognosis Long term prognosis Research Projects Research Projects Information about current and future land use Information about current and future land use Special hazards Special hazards Topography Topography Another dispersed data Another dispersed data

Data sources Regional Boards of Water Mangement (RZGW) Regional Boards of Water Mangement (RZGW) Boards of Reclamation (ZMiUW) Boards of Reclamation (ZMiUW) Institutes of Meteorology and Water Management (IMGW) Institutes of Meteorology and Water Management (IMGW) Maritime Offices Maritime Offices Research Institutes (IBW PAN, PGI, …) Research Institutes (IBW PAN, PGI, …) Local governments Local governments Centra Zarządzania Kryzysowego (Prevention Management Centers) Centra Zarządzania Kryzysowego (Prevention Management Centers) Fire Brigades Fire Brigades Citizens Citizens Other Other

Conclusion Information is dispersed Information is dispersed It is not possible to manage such information It is not possible to manage such information This information shall be collected within one manageable GIS data base This information shall be collected within one manageable GIS data base One of the general objectives for the preliminary risk assessment is to establish unique geodatabase placing all available flood information on the map.

How can we collect dispersed information? First step is to inform and aware all stakeholders about advantages of flood risk management and engage them to collaboration. All shall understand their responsibility for data sharing. First step is to inform and aware all stakeholders about advantages of flood risk management and engage them to collaboration. All shall understand their responsibility for data sharing. Second is to establish a tool simple to use for making it. Second is to establish a tool simple to use for making it. The information can be collected easier by using well designed internet portal The information can be collected easier by using well designed internet portal This portal shall give opportunity for anyone, even inexperienced, to introduce to the GIS geodatabase any flood information by simple clicking This portal shall give opportunity for anyone, even inexperienced, to introduce to the GIS geodatabase any flood information by simple clicking Data sharing have to be obligatory for main institutional stakeholders and voluntary for another. Data sharing have to be obligatory for main institutional stakeholders and voluntary for another.

Historical Floods

Flood Protection Study

Data evaluation Then after we will have fragments of rivers and coast lines where flood is possible. Then after we will have fragments of rivers and coast lines where flood is possible. There is a question of data reliability criteria There is a question of data reliability criteria The source where data come from The source where data come from Data recurrence Data recurrence Data before changes Data before changes According this criteria we can produce flood probability According this criteria we can produce flood probability

How to evaluate risk? Risk = probability x consequences Risk = probability x consequences Consequences we can for this preliminary assessment evaluate on the basis of the map of land use Consequences we can for this preliminary assessment evaluate on the basis of the map of land use For example data from Corine Land Cover Project For example data from Corine Land Cover Project

Land use by Corine Land Cover

The result

Who will do it? The idea of multi branch Project with participation of stakeholders The idea of multi branch Project with participation of stakeholders Geodatabase location – Regional Boards for Water Management Geodatabase location – Regional Boards for Water Management Before, kick off meetings to establish Before, kick off meetings to establish Project definition, Project definition, Team Team Schedule Schedule Budget Budget

No time

No money

To be continued… Flood hazard maps Flood risk maps