Questions and Answers
Why do we need new Flood Hazard and Risk Maps?
Flood hazard and risk maps (FHRM) are important information to raising population and authorities’ awareness, and to guide the urbanistic developments considering flood risk. These maps have been produced for 526 Areas of Potential Significant Risk (APSFR) scattered around the river courses within Romanian territory.
Romania developed a first set of maps in 2015, covering the most extreme flood prone areas in the country (499 APSFRs). In this second cycle, a new set of locations have been added to the initial ones, whose flood risk is also significant (526 APSFRs). New hazard and risk maps have been elaborated under this second cycle for all APSFRs, using sophisticated methods and tools. The result is a very good delineation of the potential flooded areas and the estimation of the damages generated by the floods, which gives an excellent foundation to make key flood risk management decisions.
What is a Flood Hazard?
Flood hazard refers to the physical effect of flooding, i.e., the extent of the flooded areas, the flood levels or the water velocities. The flood hazard is associated with a probability of occurrence. A flood that occurs very frequently usually has moderate damaging effects. An extreme flood, which occurs once in many years, can have large damaging effects, or high hazard.
What is a Flood Hazard Map?
The flood hazard maps represent the delimitation of areas that may be flooded for certain probabilistic scenarios. Flood hazard maps are spatial representations of water depths and velocities and are used in the assessment of potential damages and for the generation of flood risk maps.
Caution! The flood hazard maps do not represent extents of some flood events that have taken place in the past, but are based on results of probabilistic models.
What is a Flood Risk Map?
The risk maps indicate the assets that can potentially be flooded, by category: residential buildings, social, economic and cultural heritage features, transport infrastructure, agricultural land, etc, and the values of the estimated damages, associated to different AEPs, and the level of risk associated as result of combining hazard AEPs and the associated damages.
In order to create flood risk maps, it is necessary to know which areas can be flooded (information that is provided by the hazard maps), the economic value of the elements exposed in the flood zone and what damages and losses from this value we can expect, depending on the extent of flooding.
There are different types of damages, and damage estimation. In the Risk Maps, only Total Direct Tangible Damage (TDTD) and Annual Expected Damage (AED) are shown.
TDTD stands for the economic value of the material loses. TDTD can be associated to a certain AEP. The lower (more extreme) the AEP, the bigger the loses.
AED stands for the estimated annual damage, and it is a calculation based in the estimated damages for the different AEPs, by applying a weight. The AED can be understood as the damages that are caused by floods annually, as an average, in an APSFR. For example, if the damage expected by floods in the next 50 years in an area is aproximately 1 million euros, then the AED is 1M/50=20.000 €/year.
What do the probabilities mean?
Flood hazard maps for a specific APSFR are developed taking into account flows with a certain annual exceedance probability (AEP). In the second implementation cycle of the Floods Directive, several AEPs have been simulated, namely: 33%, 10%, 1%, 0.5% and 0.1%. In addition to the 5 AEPs, for all APSFRs, 1%CC has been calculated, which represents the climate change scenario. This has been done for 321 APSFRs. For the remaining APSFRs, results from the first cycle were used and the climate change scenario was calculated based on GIS methods.
As a general rule, these scenarios can be categorized into three main categories:
- - floods with a low probability of exceedance, 0.1% AEP representing the event with an average period of occurrence once every 1000 years (in some cases 0.2% have been developed instead);
- - floods with an average probability of exceedance, 1% AEP representing the event with an average occurrence period of once every 100 years. 0.5% AEP can be also included in this category;
- - floods with a high probability of exceedance, 10% AEP representing the event with an average period of occurrence once every 10 years. 33% AEP can be also included in this category;
What is a Flood Risk?
Flood risk is a combination of the flood hazard (physical characteristics of the flood) and its potential negative effects (damage) in terms of people's health, the environment, cultural heritage and economic activity.
Depending on the characteristics of the flood (eg. water depth, water speed, flood duration, etc.) and the exposed elements present in the area (e.g., residential buildings, industrial sites, roads, ports, arable land, population, etc.), the risk may vary. The damage will be significantly different if the water depth in the flood zone is 5 cm or 2 m, or if only a few exposed elements are affected or a higher number of exposed elements are affected.
Who is responsible for revising the maps?
The Ministry of the Environment, Waters and Forests (MMAP), together with the National Administration "Romanian Waters" (ANAR) and the National Institute of Hydrology and Water Management (INHGA) are the institutions responsible for the implementation of the EU Floods Directive on the territory of Romania and for the involvement of all parties relevant stakeholders in this process.
The Flood Hazard and Risk Maps were updated as part of the implementation of the "RO-FLOODS" Technical Assistance project: Strengthening the capacity of the central public authority in the field of water for the purpose of implementing the 2nd and 3rd stages of Cycle II of the Floods Directive (SIPOCA Code 734 MySmis Code 2014 130033.).
What are the benefits of the revised flood hazard and risk maps?
- The revision of the FHRM will benefit numerous stakeholders in different ways:
- - Community planners and local officials will gain a greater understanding of the flood hazards and risk that affect the communities located in the APSFRs and can therefore improve local planning activities
- - Insurance companies and lending institutions will have access to flood risk data for insurance and lending decision making
- - Home and business owners will have the ability to make better decisions about protecting or insuring their properties against floods
What is an APSFR and how do I determine if my property is located in this area?
In 2019, Romania defined Areas of Potential Significant Flood Risk (APSFR) for the second cycle in the entire country. These areas have been identified through different types of analysis and can be viewed by selecting the APSFR layer from the application that renders the flood hazard and risk maps. Alternatively, you can find out if you are in an APSFR by entering the name of your locality in the map search function and selecting the APSFR layer from the menu.
How will the new flood hazard maps affect me?
The revised maps in this second cycle of the Floods Directive will have new implications for Romanian stakeholders compared to the maps in the first cycle. There will be some properties that are not affected – their flood risk remains the same. Other properties will now be included in a higher risk zone or a lower risk zone than before. If they are in a higher risk area, a homeowner, business owner or local authority can take different steps to inform, prepare or protect themselves. See the Guides section of inundatii.ro for more information or contact the River Basin Administration in your area for more information on flood risk management measures and the actions you can take.
Where can I send my comments or reactions on the FHRMs?
The maps were reviewed and developed by a consortium of national and international experts over a period of several years, from data collection to processing and release of the public map viewer.
Efforts have been made to ensure that the maps reflect the most accurate and reliable flood hazard and risk information in the APSFRs. Institutional stakeholders were invited and involved in validating the FHRMs throughout this process. However, if upon viewing the maps you have comments or question, please contact contact-directivainundatii@inundatii.
Am I obliged by legislation to use the maps?
The FHRM are of general interest, for informational purposes. For investment activities, urban planning, etc. in-depth studies at the local level are needed. We also draw attention to the fact that these maps were developed only for certain areas/sectors called APSFR. The non-coverage of an area in our country does not mean that the said area cannot be exposed to the risk of flood.