Background to the PFRA European Overview UC10508

Transcription

1 Background to the PFRA European Overview UC10508 The individual Member State Reports reflect the situation as reported by the Member States to the European Commission in 2014 The situation in the MSs may have altered since then Assessment of Flood Hazard and Flood Risk Maps Member State Report: SI - Slovenia 26 November 2014 Information reported and assessed The schemas for electronically reporting/making information available to the Commission were filled in with a detailed level of information. Slovenia made available links to its national flood risk and flood hazard maps for its 2 units of management. Detailed summaries were provided on the methods used to prepare the maps and specific details of national maps for visualisation at the European level were also reported. No links to other relevant information on the preparation of the maps were provided. This report is structured according to a questionnaire that was completed for all Member States that reported on their flood hazard and risk maps. Questions 2 and 3 of the questionnaire were answered on the basis of a qualitative check of a subset of the Member State s flood hazard and flood risk maps located on national servers and/or web pages. All other questions (question 1 and questions 4 to 11) were answered on the basis of an assessment of numeric and summary information reported by the Member State on the methods used in the preparation of their maps. The report does not include indepth assessment of national background methodological reports which may have been referenced in the Member State s reports and/or provided with their electronic reports. This report includes information on what the Member State has included/considered or not included/considered in its flood risk and hazard maps and their development. This is a presentation of the facts on the electronic information reported to WISE by Member States and does not discuss which elements are mandatory according to the Directive and which are optional. Maps of flooding in Slovenia are available at two web portals: Atlas okolja and Atlas voda. This assessment is based on the maps provided via the web portal Atlas okolja. The maps on Atlas voda were also checked but, at the time, they were the same as those in the Atlas okolja. Main outcomes of the assessment a) Good practices adopted: The maps that are provided via the web portal, Atlas okolja, the governmental official database and an interactive map viewer, which is accessible to general public, is a great tool. The database is downloadable in different formats. One can view data and prepare maps of different kind and scale and print them directly from the application. It is intended for professional (e.g. by local authorities, environmental assessment studies, flood risk management planning) as well as general public use, as well as for public awareness. The topic of floods is generally covered by five types of maps (information) on a state level: Map of APSFRs (developed 2012, published 2013) with some numeric information on potential adverse consequences associated to the APSFR areas (Flood Risk elements). 1 of 25

2 Flood hazard maps (last update 2013 or 2014) 1 ; Flood hazard maps are very detailed and presented in two forms: (1) probability of flood events (for Q10, Q100, Q500) and (2) presenting classes of flood hazard (4 classes). Specific common methodology on a state level is decreed in 2007 and since that time, these maps are produced through different studies and placed on a common platform. Warning map of floods ( Opozorilna karta poplav ) - last update 2007; old general flood hazard map developed from information that was gathered from maps and various other sources. Flood event maps for floods from 1980 to 2010 Other maps: Infra-red aerial photo of floods in 2010 for Ljubljana b) Weaknesses: Flood hazard maps are prepared according to specific common methodology on a state level that is decreed in 2007 and, since that time, these maps are produced through different studies and placed on a common platform. Not all APSFRs are covered by these studies. This is because they are produced when there is a need for planning something in the flood area or close to it. So the level of accuracy differs from case to case, from study to study, but in general it is very good (minimum required scale is 1:5,000 and up to scale 1:1,000 or more). Besides that, each study has to be approved by the state office and then it is integrated into the state database. However, one APSFR can be covered by several such separate studies, or some parts of the APSFRs are not covered at all. Through time, this weakness will be dealt with. Numeric information on potential adverse consequences is associated with the APSFRs as part of the APSFR map (the layer showing only the extent of APSFR). Some of the required topics are missing. The SI Authorities subsequently indicated that the statistics on the number of inhabitants potentially affected were produced for the PFRA but not the mapping of flood risk. However the number of potentially affected inhabitants by medium probability floods was provided for some of maps reported to WISE for some but not all APSFR: for others the number was reported as yet to be measured. There is no distinction among different flood sources (fluvial, pluvial, sea-water, groundwater, etc.). They are all presented as one integral flood layer (with different return periods) in the maps. The SI authorities subsequently reported that the flood hazard maps sometimes include information about flood extent of other flood sources. c) Lessons to be learnt: Implementing a specific common methodology on a state level for preparing flood hazard maps (decreed in 2007), and making it mandatory for each development plan or project that can have an impact on floods, is a good way of optimising the available resources. 1 Subsequent to the assessment, the SI authorities commented that the maps were updated in early 2015 and that the integrated maps would be updated in summer The maps that were subject to the assessment were last updated in 2013 or of 25

3 Subsequent to the assessment, the SI authorities stated that more detailed and more accurate flood hazard maps and flood risk maps for certain APSFRs are under construction. d) Questions seeking clarification from Member State. Subsequent to the assessment, the SI authorities responded to the questions, as shown below: 1. "Source: 3030, 3021, 3067 and 3129" or some other numbers are written on hazard maps right after the title of a map. This seems to refer to the source of information. What are these codes? Do they refer to the separate studies? Please explain. SI response: These numbers refer to internal codes of individual hydrologic-hydraulic studies, which were allocated at the Institute for Water of the Republic of Slovenian Environment Agency (SEA/ARSO) in the process of reviewing the compliance of studies with methodological rules (in the process of obtaining the water consent). Studies represent a data source for preparing data layers with flood extent lines, depths classes, hazard classes and the area covered by the validated results. If any individual APSFR is overlapped by the areas covered by more than one study, the results for each study are combined according to uniform rules to derive the combined flood extent lines, depths and hazard classes. The hazard map also lists codes of individual studies, as through them it is possible to trace the emergence of individual lines of hazard classes. 2. One APSFR is covered by several separate areas where the calculated data is correct. (map provided in the LinkToMS schema). These areas refer to the results of different studies. Why isn t one APSFR entirely covered by one such study? SI response: Individual hydrologic-hydraulic (flood) studies are prepared in accordance with the provisions of the methodological rules (2007) and, since 2008, have been used in the procedures for obtaining the water consent as a basis for the conditions and limits for the implementation of activities and interventions in flood areas. The whole area of APSFR is therefore covered by the results of several studies that have been merged and coordinated in a joint map for each APSFR. 3. What are the differences among the layers (event scenarios with return period 10, 100, 500 years) that are used in the Flood Hazard maps presented through the LinkToMS schemas and the Flood Hazard maps presented through "Atlas okolja" via web portal which is available to general public? SI response: In principle, the difference is only in the digital format (charts (PDF format) and data layers (SHP format)). Data on Flood Hazard maps in PDF format are consistent with the data layers on Integrated Flood Hazard maps in SHP format, published on the Environmental Atlas and Water Management Atlas, of course taking into account the timing of producing the maps and updating the layers. 4. Are there any differences in numeric information between the Flood Risk maps in the LinkToMS schema and the numeric information on potential adverse consequences associated to the APSFR areas in the "Atlas okolja"? SI response: Statistics of people at risk of flooding in APSFRs obtained in the Preliminary flood risk assessment is made on the basis of methodological guidelines and data layers other than the ones used for preparing Flood Hazard maps for the years , so there are some differences in numerical information. Statistics in APSFRs were prepared 3 of 25

4 within a non-generalised polygon of network cell size of 75 m, where certain types of atrisk people were selected on the basis of data layers used in the preparation of classification of flood-risk areas maps. For flood risk maps a set of potential at-risk people was slightly modified, as shown in the legend on the map. In particular, the statistics of atrisk people refer to the whole area covered by the validated results of all studies that are at least partially located in the area of potentially significant flood risk, i.e. the area of flood risk is significantly expanded. 5. For Piran (APSFR SI5_42) and Dravograd (APSFR SI3_08) there is no other information available except for the Areas of Potentially Significant Flood Risk and associated numeric information on potential adverse consequences. Is that true and why? SI response: For APSFR SI5_42 Piran Flood Hazard maps and Flood Risk maps are prepared and available on the Water Management Atlas and on the Environmental Atlas (with a click to APSFR/OPVP, links to individual maps in a PDF file are opened). They are also available through an Excel spreadsheet on MESP s web site: A detailed Flood Hazard map Q100 for APSFR Piran is available on: KPO/ogrozenost_Q500_Piran.pdf In addition, links to maps for APSFR Piran are included in the updated reporting forms. For APSFR SI3_08 Dravograd, the estimated potential consequences of flooding (number of inhabitants, number of employees, number of cultural monuments, number of IPPC and SEVESO facilities, etc.) are within the layer APSFR/OPVP. Within the Flood Indication Map Flood Hazard is mapped with less precision. In the area of Dravograd construction and implementation work of EU cohesion project Drava is ongoing (for period ), which significantly alters the hydrologic and hydraulic situation in the area. 6. It seems that there is no distinction amongst the sources of floods (fluvial, pluvial, groundwater, sea water, etc.). Are there or will there be separate layers prepared for each relevant source of floods? SI response: Preparing separate data layers depending on the source of flooding is not foreseen; there are currently only divisions between the flooding of watercourses and flooding of the sea and lakes. In the case of overlapping of the flood extents from the two sources, a common area with validated results and combined flood extent lines, depths and hazard classes is prepared by the uniform rules (e.g. APSFR Izola and APSFR Koper). 7. How and when are the separate layers of information updated (in "Atlas okolja")? SI response: Integral maps on the Water Management Atlas and the Environmental Atlas (Integral flood hazard map, Integral flood hazard classes map and Integral map of water depth at Q100) are updated approximately every 6 months. Flood risk maps and Flood events maps are updated every 6 years; the same goes for Areas of potentially significant flood risk and Flood Risk maps. 4 of 25

5 8. The classes of Flood hazard are not explained in the "Atlas okolja". There is just a reference to the methodology that was decreed. Should there be an explanation of classes in terms of depth of water, etc.? SI response: Flood hazard classes are explained in more detail in the metadata of each layer (flood hazard class) under ikrpn Si (integrated flood hazard classes maps), so is, for example class of high flood hazard explained in metadata at the web address: where it is written in the abstract: On the basis of criteria which classify the strength of the flood flow at the same probability of occurrence of the event, flood hazard areas are graded into flood hazard classes, with the decisive criterion of one, which shows the greatest hazard class. The planar spatial objects represent volume of significant flood hazard areas class (Pv), where the water depth is same or greater than 1.5 m at the flow of Q100 or surface G100 or the product of depth and speed of water is same or greater than 1.5m 2 /s. In addition, flood hazard classes and the methodology of their determination are clearly defined in Rules on the methodology for determination of flood risk areas and, with them, associated erosion of inland and marine waters, and the method of classifying land into the risk classes (Official Journal of the Republic of Slovenia, No. 60/07): 5 of 25

6 Mapping of areas of potential significant flood risk Question 1: What are the reasons reported in the FHRM schema for the non-inclusion of some APSFRs, elements or aspects in the flood hazard and flood risk maps? SI reported links to maps of each of the APSFRs identified according to Article 5, and also details of the maps in the FHRM schema. The links were to maps that were at the time of the assessment (November 2014) not publicly available. However, there were flood hazard maps that were available to the public on a government web portal, and the content is basically the same (very small differences). They are presented as interactive maps where one can zoom in from the state level to the property. Areas of Potential Significant Flood Risk (APSFR) and other risk areas identified by the assessment of flood risk and those for which maps were prepared Unit of Management Number of Areas of Potential Significant Flood Risk (1) a) Identified according to Article 5 b) with links to national maps c) with details of maps provided to WISE FHRM information reported at Unit of Management scale (2) b) with links to national maps c) with details of maps provided to WISE Number of other areas with available national FHRM (3) b) with links to national maps SI_RBD_ No No 0 SI_RBD_ No No 0 Key: a) Article 5 requires the identification of areas of potential significant flood risk (APSFR) based on a new Preliminary Flood Risk Assessment or an existing one. b) Member States were asked to provide links to national web pages or viewers where maps of the flood hazard and flood risk associated with APSFRs could be viewed (column 1). Alternatively or additionally maps could be made available and reported at the level of the Unit of Management (column 2) or at other geographical scales (column 3), c) Member States were asked to provide numeric details (such as source of flooding, numbers of potentially affected inhabitants and types of potential adverse consequences) of the maps associated with the APSFR so that they could be depicted on a European map of flooding. The maps could be reported with the relevant APSFR code (column 1) and/or at the level of the Unit of Management (column 2). In some circumstances, (c) may be greater than (a), for example if additional APSFRs were identified after of 25

7 Content of flood hazard and flood risk maps Note: Not all of the maps prepared by Member States have been examined. Instead a subset was selected and reviewed by designated assessors. The maps for checking were selected on the basis of information provided by Member States with their Preliminary Flood Risk Assessments (PFRAs) in 2012 (where available) and the screening of the maps made available in the LinkToMS schema. The aim was to select a sufficient number of maps to reflect: Potential differences in methodologies, presentation and visualisation of maps between the Units of Management (UoM) within a Member State. Some Member States have a strong national approach, in others there are differences between administrative regions; Differences in sources of floods included in hazard and risk maps. Some APSFRs and UoM are associated with more than one source of flooding whereas others are not. The aim was to check maps associated with all possible types of flood associated with a Member State. For those Member States applying Article 4 and Article 13.1.a the selection of relevant flood types can be informed from the reporting of APSFR in March 2012; Differences in the Articles applied across a Member State and within UoMs. Whilst some Member States have applied only one Article across their whole territory and for all flood types, others have applied different Articles within a UoM and also according to flood types. The application of Article 13.1.b and Article 13.2 by some Member States in at least some of their UoMs. In these cases Member States may have provided UoM codes, other area codes or both: in these cases it was the flood maps associated with the areas that were checked. The objective was to check examples of maps within the linked areas in relation to all potential and relevant sources of flooding and that may have been mapped. Links to national web pages where examples of national maps can be viewed are given below. Question 2 Which types of flood, scenarios, hazard elements and potential adverse consequences have been mapped and visualised? Unit of Management SI_RBD_1 SI_RBD_1 SI_RBD_1 SI_RBD_1 SI_RBD_1 SI_RBD_2 SI_RBD_2 SI_RBD_2 APSFR code SI1_01 SI1_01 SI1_12 SI1_12 SI3_08 SI15_03 SI15_03 SI5_42 The provided link went straight to the APSFR Yes No Yes No No Yes No No Map located by searching for name of APSFR N/A Yes N/A Yes Yes N/A Yes Yes Source(s) of flooding mapped Not clear Not clear Not clear Not clear None Not clear Not clear None Mechanism(s) of flooding mapped None Not clear None Not clear None None Not clear None Characteristic(s) of flooding mapped None None None None None None None None Linked map available to public (1) No / Yes Yes No / Yes Yes Yes No / Yes Yes Yes Mapped scenarios Floods with a low probability mapped Yes Yes Yes Yes Yes Yes Yes No Floods with a medium probability mapped Yes Yes Yes Yes Yes Yes Yes No Floods with a high probability mapped Yes Yes Yes Yes Yes Yes Yes No 7 of 25

8 Unit of Management SI_RBD_1 SI_RBD_1 SI_RBD_1 SI_RBD_1 SI_RBD_1 SI_RBD_2 SI_RBD_2 SI_RBD_2 APSFR code SI1_01 SI1_01 SI1_12 SI1_12 SI3_08 SI15_03 SI15_03 SI5_42 Separate maps or layers for each probability scenario Yes Yes Yes Yes Yes Yes Yes No Separate maps or layers for each flood type No No No No No No No No More than one scenario shown on the same Map No Yes No Yes Yes No Yes No More than one source of flooding shown on the same Map Yes Yes Yes Yes Yes Yes Yes No Hazard Elements shown on map Flood extents Yes Yes Yes Yes Yes Yes Yes No Water depth (2) No No No No No No No No Water levels No No No No No No No No Flow velocities (3) No No No No No No No No Relevant water flow No No No No No No No No Flood Hazard and Flood Risk on the same map No No No No No No No No Separate maps of Flood Hazard and Flood Risk Yes Yes Yes Yes No Yes Yes No Potential adverse consequences shown on: Number of Inhabitants potentially affected Yes Yes Yes Yes Yes Yes Yes Yes Human health Yes Yes Yes Yes Yes Yes Yes Yes The community Yes Yes Yes Yes Yes Yes Yes Yes Type and sectors of economic activity No Yes No Yes Yes No Yes Yes Land use Yes No Yes No No Yes No No Point locations for storage of chemicals, vital networks and services Yes No Yes No No Yes No No Property Yes Yes Yes Yes Yes Yes Yes Yes Infrastructure Yes No Yes No No Yes No No Location of Industrial Emissions Directive installations Yes Yes Yes Yes Yes Yes Yes Yes WFD Protected Areas Yes No Yes No No Yes No No Status of water bodies No No No No No No No No Areas vulnerable to floods with high content of transported sediment and debris flow No No No No No No No No Other significant sources of pollution Yes No Yes No No Yes No No Cultural Heritage Yes Yes Yes Yes Yes Yes Yes Yes Other useful information No Yes No Yes Yes No No No Impacts of Climate Change No No No No No No No No Coastal protection defences in place No No No 8 of 25

9 (1) Areas marked No/Yes had links to maps reported in the schemas but those links were not publicly available at the time of the assessment. However, there were flood hazard maps that were available to the public on a government web portal, and the content is basically the same (very small differences). Subsequent to the assessment, the SI authorities clarified that the maps are available in an Excel spreadsheet on the MESP s web site or through the Water Management Atlas or the Environmental Atlas. (2) water depths were not found on the maps during the assessment. However, subsequent to the assessment, the SI authorities stated that Classes of water depths (0-0.5 m; m; above 1.5 m) are publicly available in an Excel spreadsheet on MESP s web site or through the Water Management Atlas or the Environmental Atlas. (3) Subsequent to the assessment, the SI authorities stated that, for some areas (where applicable), the speed of water (less than 1m/s and greater than 1m/s) are shown, for example, for APSFR Litija depths and speed for Q500 are shown on the map on the link: Links to national maps: Links provided via the LinkToMS schema (available to the public via an Excel spreadsheet on the website of the Ministry: SI1_01 nija_q500.pdf SI1_12 oplavna_linija_q10.pdf SI5_42 Atlas Okolja: 9 of 25

10 Contextual information provided with maps Question 3 What contextual information was generally provided with the maps? Unit of Management SI_RBD_1 SI_RBD_1 SI_RBD_1 SI_RBD_1 SI_RBD_1 SI_RBD_2 SI_RBD_2 SI_RBD_2 APSFR code SI1_01 SI1_01 SI1_12 SI1_12 SI3_08 SI15_03 SI15_03 SI5_42 Title: brief description of the map Yes Yes Yes Yes Yes Yes Yes Yes Explanation to the public on how to understand and interpret the flood maps No Yes No Yes Yes No Yes Yes Responsible authority (organisation responsible for the development and publishing of the maps, with contact details) Yes Yes Yes Yes Yes Yes Yes Yes Date of preparation / publication Yes Yes Yes Yes Yes Yes Yes Yes Legend (textual description of symbols, colours, line features, etc.) Yes Yes Yes Yes Yes Yes Yes Yes Purpose of development and intended use No Yes No Yes Yes No Yes Yes Method of development No Yes No Yes Yes No Yes Yes Limitations of map and / or assessment of uncertainty No Yes No Yes Yes No Yes No Disclaimer (to enforce explanatory information and limitations, and provide legal protection to the responsible authority against adverse consequences of misuse) No Yes No Yes Yes No Yes Yes North and scale: preferably using scale bar as this allows for changes in page size Yes Yes Yes Yes Yes Yes Yes Yes Scope and detail of the explanatory information: should be appropriate to the intended audience Intended audience & complexity: Maps intended for public use should be simple and selfexplanatory and include a clear legend, such that as little supporting or explanatory information as possible is required for correct interpretation. Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes 10 of 25

11 Summary of findings from questions 2 and 3. The same approach was used in both sub-units. There is a national approach with uniform methodology described in the Rules on methodology to define flood endangered areas and associated erosion of continental and sea waters, and classification of lands in classes of endangerment (Pravilnik o metodologiji za določanje območij, ogroženih zaradi poplav in z njimi povezane erozije celinskih voda in morja, ter o načinu razvrščanja zemljišč v razrede ogroženosti, Uradni list RS, št. 60/07). The maps provided with direct links in the LinkToMS schema are all in PDF form and were not publicly accessible at the time of the assessment, although the SI authorities have subsequently stated that the maps are available through an Excel spreadsheet on the MESP s website, on the Water management Atlas and on the Environmental Atlas (layer APSFR/OPVP). At the time of the assessment, maps were publicly available via a web viewer only for certain APSFRs; of those assessed, the following APSFRs were available in the web viewer: SI1_01; SI1_12; SI15_03. They are all prepared for each APSFR separately. For the other APSFRs that were assessed (SI3_08 and SI5_42), the LinkToMS schema provides a link to the official governmental Flood Directive web site. There is a link provided to Atlas okolja (Atlas of Environment) Atlas okolja is a governmental official database and an interactive map viewer which is accessible to the general public without any restrictions or limitations. The database is downloadable in different formats. One can prepare maps of different kind and scale and print them directly from the application. It is intended for professional as well as general public use, as well as for public awareness. The content of Flood Hazard maps (probability of flood events for return periods 10, 100 and 500 years) seems to be more or less the same in both the LinkToMS and the national portal (LinkToMS schema seems to provide a bit newer information). At the national portal Atlas okolja, there is another set of flood hazard maps available, which presents the content in four categories (please see below) of flood hazard that take into account not only the extent of flood at different return periods, but also water speed, water depth and water flow. With higher speed of water flow, the flood hazard category can be higher. Flood hazard maps are very detailed (minimum required scale 1:5,000 and up to scale 1:1,000 or more). At the time of the assessment, the Flood Risks maps were not available via the national portal Atlas okolja. However, numeric information on potential adverse consequences was associated with the Areas of Potentially Significant Flood Risk (APSFR) as part of the APSFR map (the layer showing only the extent of APSFR). The Flood risk information presented in the maps provided through the LinkToMS schema does not cover the following required topics: (1) Type and sectors of economic activity in potentially affected area such as manufacturing, construction, retail, services and other sources of employment; (2) Consequences on the status of water bodies; (3) Areas vulnerable to floods with a high content of transported sediment and debris flows. The Flood risk information presented at the national portal Atlas okolja associated to the APSFR does not present the following required topics: (4) Human health such as might arise from pollution or interruption of services related to water supply and treatment, and would include fatalities; (5) Land use (e.g. agricultural land); (6) Point locations for storage of chemicals, vital networks and services (highways, railways, airport, lifeline services like electricity, sewerage and drinking water, hospitals, etc); 11 of 25

12 (7) Infrastructure such as utilities, power generation, transport, storage and communication; (8) Location of potentially affected WFD protected areas; (9) Consequences on the status of water bodies; (10) Areas vulnerable to floods with a high content of transported sediment and debris flows; There is no distinction among different flood sources (fluvial, sea-water, groundwater etc) they are all presented as one integral layer in the maps. All the contextual information is provided in the web application. 12 of 25

13 Methodologies used to prepare flood hazard maps Question 4 What methods and relevant information have been used to identify, assess or calculate flooding hazards for the relevant scenarios, and are these compliant with the requirements of the Floods Directive? The sources of flood for which flood hazard maps have been published, or which have been assessed but flood hazard maps have not been published, were: Source of flooding Fluvial Pluvial Published SI_RBD_1, SI_RBD_2 Assessed but not published Neither published nor assessed Not relevant SI_RBD_1, SI_RBD_2 Coastal SI_RBD_2 SI_RBD_1 Groundwater Artificial water bearing infrastructure Sewerage systems Other (described below if applicable) SI_RBD_1, SI_RBD_2 SI_RBD_1, SI_RBD_2 SI_RBD_1, SI_RBD_2 Other: Not relevant Comments There are no differences between both UoMs in the Member State. There is no differentiation among different flood sources at presentation of flood hazard maps. All considered flood sources (namely fluvial and sea-water) are integrated into one flood map (presented in three scenarios for 10, 100 and 500 year return period). However, WISE Floods summery report (FD.9.0 FHRM A) provides the information on different methodology used to analyze floods from different sources (rivers, lakes and seawater). The sources of flooding that were included as fluvial are also lakes, artificial water bearing infrastructure, groundwater and pluvial. A) Fluvial floods Scenarios mapped or assessed Scenario Return period e.g. 100 years Percentage e.g. 1% Decimal e.g Other expression Low probability 500 four classes of flood hazard Medium probability 100 four classes of flood hazard High probability 10 four classes of 13 of 25

14 flood hazard Summary of the information found and in particular any differences between the UoMs in the Member State. The probability scenarios have been expressed in two different ways (two different sets of maps): (1) In terms of return period (10, 100 and 500 years), and (2) In terms of four classes of flood hazard at water flows at rivers and water levels at lakes corresponding to 100 year return period taking into account water depth and water speed. There are no differences between the UoMs in the MS because one common methodology is mandatory for the whole country. The sources of flooding that were included as fluvial are also lakes, artificial water bearings and pluvial. Elements mapped or assessed Scenario Flood extent Water Water/flow Other depth/level* velocities* Low probability Yes No No combination of water depth and speed at specific water flow Medium probability Yes No No combination of water depth and speed at specific water flow High probability Yes No No combination of water depth and speed at specific water flow * Subsequent to the assessment, the SI authorities stated that water depth classes for scenarios Q10, Q100 and Q500 are displayed on the maps and the same goes for velocity, where appropriate. Summary of the information found and in particular any differences between the UoMs in the Member State. The flood hazard maps are prepared according to decreed methodology, therefore, there are no differences between the UoMs in the MS. Flooding hazard maps are prepared in two different ways (two sets of maps). The first set of maps presents flood hazard as flood extent for return periods 10, 100 and 500 years. The second set of maps presents flood hazard in an integral way as four classes of flood hazard. Flood hazard classes where defined as combination of water depth and water speed (greater than 1 m/s) at water flows at rivers and water levels at lakes corresponding to 100 year return period is taking into account: (1) The class of high hazard: water depth 1,5 m or product of water depth and speed is 1,5 m 2 /s; (2) The class of medium hazard: water depth less than 1,5 m and 0,5 m or product of water depth and speed is less than 1,5 m 2 /s and 0,5m 2 /s; (3) The class of low hazard: water depth less than 0,5 m or product of water depth and speed is less than 0,5 m 2 /s; (4) The class of very low hazard: when flood is caused by exceptional natural or man-made causes (heavy rain, malfunction or destruction of flood defence and other water structures etc.); 14 of 25

15 Methods used What scenarios were considered and tested in the development of the published maps? What were the reasons for the exclusion or inclusion of certain scenarios for the final published maps? How were return periods and/or probabilities of flooding calculated, for example what was the length of measurement series used in the calculations? How was the most appropriate scale of the map determined? For example, flood maps intended to raise public awareness should enable anyone to find out where there are risks of flooding. Maps for this purpose may have a relatively larger scale e.g. 1: 10,000 to 1: 25,000 compared to those used for national or regional planning purposes (1:100,000 to 1: 500,000). Also the mapping of some hazard features such as flow velocity may require a more detailed scale such as 1:1,000 or 1:5,000. What was the resolution of digital terrain models used to calculate flood hazards? How were existing flood defences taken into account? How were existing infrastructure or buildings taken into account? Scenarios for high (10), medium (100) and low probability (500 year return period) were considered and tested in the development of the published maps. All included. No further explanation provided. (Not prepared for all the APSFRs.) The decreed methodology defines probabilities of certain flood risk with standard probabilities of the appearance of flows with return periods 10, 100 and 500 years. For defining the quantity of water flow with probability of 500 year return period the methodology allows also simplified calculation: - for river catchments larger than 1000 km 2 the equation Q500 = 1,2 * Q100 is used; - for catchments greater than 100 km 2 and smaller than 1000 km 2 the equation Q500 = 1,3 * Q100 is used; - for catchments smaller than 100 km 2 the equation Q500 = 1,4 * Q100 is used. In the case of lakes, the maximal measured water level is used. The methodology does not define the length of measurement series used in the calculations. This depends on best available information for each separate case. The minimal accuracy of the flood hazard maps is decreed and it is 1:5,000. The flood hazard maps presented in the PDF form via direct links in the LinkToMS are prepared in scale 1:5,000. The maps provided through governmental official database in the interactive map viewer Atlas okolja (Atlas of Environment) can be enlarged up to the scale 1:1, =Atlas_Okolja_AXL@Arso The resolution of digital terrain models used to calculate flood hazards was minimum 1:5,000 or larger (basic topographic maps). Besides that, data gathered with the use of LiDAR technique of capturing geodetic data have 7,5 cm accuracy for height and density of 10 points per m 2. For the river beds of the main rivers, bridges and other hydraulically important structures field geodetic measurements were prepared. Data gathered with the use of LiDAR technique captured existing flood defences. No further information is provided. In modelling, buildings are taken into account as high walls. Data gathered with the use of LiDAR technique captured existing infrastructure or buildings. No further information is provided. Subsequent to the 15 of 25

16 What other data sets were used? What are the key assumptions of the method? What were the identified uncertainties in the methods and resultant maps and assessments? What were the shortcomings of the method? What were the advantages of the method? assessment, the SI authorities stated that the buildings cadastre is taken into account in the modelling. For the modelling of pluvial runoff, all available pluvial data series were used. Key assumptions of the method are: (1) Climatic variability was considered with the analysis of all recorded pluvial and water flow values. (2)The low probability scenario (500 year return period) equals the extent of flooding in the case of malfunction of flood defence structures (as that they were not build). (3) The potential effects on flood risk of spatial planning policies such as those on land use and infrastructure development have not been considered in Slovenia, because protective measures are being carried out with the help of the Decree on conditions and limitations for constructions and activities on flood risk areas, which ensures that the mass of damaging potential from human activity is not increasing due to re-directing new developments outside of flooding areas. In the case of foreseen enlargements of existing infrastructure in the areas already endangered by floods, mitigation measures have to be implemented to reduce existent endangerment. There is no information on identified uncertainties in the methods and resultant maps and assessments except the observation,that calculated extents of floods does not necessarily match the observed extents of floods because of possible changes of water bed, obstructions of water flow, etc. There is no information on the shortcomings of the method. There is no information on the advantages of the method. B) Pluvial floods Note: Pluvial flooding was combined/mapped with fluvial flooding. C) Coastal floods Scenarios mapped or assessed Scenario Return period e.g. 100 years Percentage e.g. 1% Decimal e.g Other expression Low probability 500 four classes of flood hazard Medium probability 100 four classes of flood hazard High probability 10 four classes of flood hazard 16 of 25

17 Summary of the information found and in particular any differences between the UoMs in the Member State. The probability scenarios have been expressed in two different ways: (1) In terms of return period (10, 100 and 500 years), and (2) In terms of four classes of flood hazard at water levels of sea corresponding to 100 year return period taking into account water wave with return period 50 years. The methodology is relevant only in one UoM. Pluvial sources of flooding were also included as well as sea water flooding. There is no separate layer for sea water sources of flooding. Sea water flooding is integrated within fluvial flooding. Elements mapped or assessed Scenario Flood extent Water Water/flow Other depth/level* velocities* Low probability Yes No No combination of water level and water wave Medium probability Yes No No combination of water level and water wave High probability Yes No No combination of water level and water wave * Subsequent to the assessment, the SI authorities stated that water depth classes for scenarios Q10, Q100 and Q500 are displayed on the maps and the same goes for velocity, where appropriate. Summary of the information found and in particular any differences between the UoMs in the Member State. The flood hazard maps are prepared according to decreed methodology, therefore, there are no differences between the UoMs in the MS. Flooding hazard is presented in first set of maps as flood extent for each scenario (for return periods 10, 100 and 500 years). In the second set of maps, it is presented as four classes of flood hazard where combination of water levels at sea corresponding to 100 year return period and water wave with 50 year return period is considered: (1) The class of high risk: water depth 1,5 m; (2) The class of medium risk: water depth less than 1,5 m and 0,5 m; (3) The class of low risk: water depth less than 0,5 m; (4) The class of very low risk: when flood is caused by exceptional natural or man-made causes (heavy rain, malfunction or destruction of flood defence and other water structures etc.); Methods used What scenarios were considered and tested in the development of the published maps? What were the reasons for the exclusion or inclusion of certain scenarios for the final Scenarios for high (10), medium (100) and low probability (500 year return period) were considered and tested in the development of the published maps. All included. No further explanation provided. (Not prepared for all the APSFRs.) 17 of 25

18 published maps? How were return periods and/or probabilities of flooding calculated, for example what was the length of measurement series used in the calculations? How was the most appropriate scale of the map determined? For example, flood maps intended to raise public awareness should enable anyone to find out where there are risks of flooding. Maps for this purpose may have a relatively larger scale e.g. 1: 10,000 to 1: 25,000 compared to those used for national or regional planning purposes (1:100,000 to 1: 500,000). Also the mapping of some hazard features such as flow velocity may require a more detailed scale such as 1:1,000 or 1:5,000. What was the resolution of digital terrain models used to calculate flood hazards? How were existing flood defences taken into account? How were existing infrastructure or buildings taken into account? What other data sets were used? What are the key assumptions of the method? What were the identified uncertainties in the methods and resultant maps and assessments? What were the shortcomings of the method? What were the advantages of the method? The decreed methodology defines probabilities of certain flood risk with standard probabilities of the appearance of water level with return ages 10, 100 and 500 years. The methodology does not define the length of measurement series used in the calculations. This depends on best available information for each separate case. The minimal accuracy of the flood hazard maps is decreed and it is 1:5,000. The flood hazard maps presented in the PDF form via direct links in the LinkToMS (not publically accessible) are prepared in scale 1:5,000. Public accessible maps provided through governmental official database in the interactive map viewer Atlas okolja (Atlas of Environment) can be enlarged up to the scale 1: d=atlas_okolja_axl@arso The resolution of digital terrain models used to calculate flood hazards was minimum 1:5,000 or larger (basic topographic maps). Besides that, data gathered with the use of LiDAR technique of capturing geodetic data have 7,5 cm accuracy for height and density of 10 points per m 2. For hydraulically important structures field geodetic measurements were prepared. Data gathered with the use of LiDAR technique captured existing flood defences. No further information is provided. In modelling buildings are taken into account as high walls. Data gathered with the use of LiDAR technique captured existing infrastructure or buildings. No further information is provided. Subsequent to the assessment, the SI authorities stated that the buildings cadastre is taken into account in the modelling. For the modelling of pluvial runoff, all available pluvial data series were used. Key assumptions of the method are: (1) Climatic variability was considered with the analysis of all recorded pluvial and water flow values. There is no information on identified uncertainties in the methods and resultant maps. There is no information on the shortcomings of the method. There is no information on the advantages of the method. 18 of 25

19 D) Groundwater floods Note: Groundwater flooding is not specifically mapped and there is no explicit mention that groundwater flooding was considered to be a part of fluvial flooding. However, the recorded historic data that was taken into consideration did not make any distinction between groundwater and fluvial flooding. Slovenia also has large areas of karst where it is especially hard to distinguish between groundwater floods and fluvial floods. E) Floods from Artificial Water Bearing Infrastructure Note: Flooding from artificial water bearing infrastructure was combined/mapped with fluvial flooding. F) Floods from sewerage systems Note: No information was found on whether the hazard and risk of flooding from this source has been mapped. G) Other types of floods Note: No information was found on whether the hazard and risk of flooding from other sources have been mapped. 19 of 25

20 Methodologies used to prepare flood risk maps Question 5 What methods and relevant information have been used to prepare flood risk maps? Which potential adverse consequences are reported and how have they been identified and presented in flood risk maps? a) Risk to human health The indicative number of inhabitants potentially affected by each flooding scenario is determined by spatial data analyses of the central register of population (Ministry of the Interior of Republic of Slovenia, 2014) and data of register of spatial units records of house numbers (Geodesy Administration of the Republic of Slovenia, 2014). Permanent and temporary inhabitants are considered. The number of people at potential risk in each APSFR have then been rounded into a number of categories (e.g. 1-50, , , and more than 1000 inhabitants per km 2 ) and symbolically presented on Flood risk maps. There are no differences in the methods and criteria used within the Member State. b) Risk to economic activity Risk assessment to determine economic activity affected, for each flood scenario the location of economic activity was analyzed. Spatial data of actual land use using nomenclature of Corine Land Cover (European Environment Agency, 2006) was used since the national data layer of actual land use does not give a separate category for industrial, retail and transportation areas. The Corine Land Cover categories were reclassified into five categories (industrial, retail and transportation area, residential area, agricultural area, park area, water area) that are presented on flood risk maps. To increase the accuracy, for each of the categories, the number of businesses affected by floods was defined by spatial analysis of data from national business registry and national registry of house numbers. To present the influence of floods on transportation, spatial data on roads and railroads from national registry of economic infrastructure was used. There are no differences in the methods and criteria used within the Member State. The risk to economic activity is visualized on the maps (maps included into the LinkToMS shema) with five categories of land use (industrial, retail and transportation area, residential area, agricultural area, park area, water area) or as location of roads and railroads that area at risk. In the public viewer "Atlas okolja" the flood risk is provided as the number of working places and businesses in a particular APSFR that are at risk because of flooding, as well as a number of kilometers of roads and railroads that area at risk in a particular APSFR. A table with numeric information is associated with each APSFR. c) Risk to Installations covered by the requirements of the Industrial Emissions Directive (IED) or previously under the IPPC Directive Risk assessment to determine industrial installations affected, for each flood scenario, the location of installations covered by the requirements of the Industrial 20 of 25

21 Emissions Directive (IED) or previously under the IPPC Directive have been assessed on the base of spatial distribution and size. To increase the level of accuracy, communal wastewater purification plants, communal dumping sites and companies liable under the Seveso Directive were also assessed on the base of spatial distribution and size. Because these data layers are mostly given only by one geodetic point, the actual risk was determined by visual assessment of digital ortographic photographs in a scale 1:5,000 and data layers of flood risk categories. There was no special focus on activities or installations with a high pollution potential through the release of pollutants into water or land rather than those that potentially only release pollutants into the air. All chosen industrial installations were treated equally. The risk to installations covered by the requirements of the Industrial Emissions Directive (IED), communal wastewater purification plants, communal dumping sites and companies liable under the Seveso Directive are visualised on the maps with specific signs at the location (maps included into the LinkToMS schema). In the public viewer "Atlas okolja" the flood risk is provided in as number of installations (IED installations, communal wastewater purification plants, communal dumping sites and companies liable under the Seveso directive) in a particular APSFR that are at risk at flooding. There are no differences in the methods and criteria used within the Member State. d) Risk to WFD protected areas Risk assessments used to determine, for each flood scenario, the risk to the types of protected area in areas potentially at risk from flooding, were prepared using spatial analyses of data layers of water-protection areas, of bathing waters, of Natura 2000 sites, of ecologically important areas, and of natural heritage protected areas. The method that was used is simply the identification of such areas within the flooding areas. There are no differences in the methods and criteria used within the Member State. e) Other consequences considered The methodology defined in the Rules on methodology to define flood endangered areas and associated erosion of continental and sea waters, and classification of land in classes of endangerment (Pravilnik o metodologiji za določanje območij, ogroženih zaradi poplav in z njimi povezane erozije celinskih voda in morja, ter o načinu razvrščanja zemljišč v razrede ogroženosti, Uradni list RS, št. 60/07) considers also potential risk to sensitive buildings: (1) Where evacuation can be difficult (schools, kindergartens, hospitals, health centres, homes of elderly people and health resorts); (2) Where exceptional material, cultural or social damage can occur (libraries, museums, archives); (3) Where damages can cause large indirect economic loss (transport, supply); (4) Location of emergency services (fire fighting, rescue and police stations); 21 of 25