Flood Warning Map

Article 5 of the Rules on the methodology for the determination of areas threatened by floods and associated erosion of inland waters and the sea and on the method of classifying land in risk classes (Official Gazette of the Republic of Slovenia, No 60/07) defines the assessment of flood risks as the basis for determining flood zones and their classification. The results of the assessment shall be shown on the flood warning map containing information on topography and land use and shall also be marked within river basins and sub-basins (Article 8): — the boundary line of the potential flood range, or part of the flowing and standing waters or the part of the coast of the sea where flooding is known to occur, including an indication of the direction of flooding, — the boundary line of the possible extent of erosion phenomena or parts of liquid and standing waters or part of the coastline of the sea where erosion is known to occur, — spots of individual flood events with point markings, — point or line markings of individual water facilities where flooding and erosion may occur due to faulty operation or demolition. The flood and erosion warning map shall also contain a text section describing flood and erosion events, in particular those likely to recur in the future, and in particular the date, the source of the data, the description of the event and the consequences on human life and health, the environment, economic and non-economic activities, cultural heritage and other relevant information on the situation in a given area. The flood and erosion warning map may, where appropriate, also contain estimates of future floods and erosion and their consequences on people’s lives, the environment, the development of economic and non-economic activities, taking into account long-term planned developments and climate change. The coverage shall contain the flooding areas shown that have been recorded during flood events or modelled as part of the production of hydrological-hydraulic studies or referred to in other sources. Plot spatial objects represent the envelope of flood achievement in various events or event scenarios. The purpose of the data layer is to show spatially the possible locations, extent and frequency of flooding, which can serve to warn about flood risks in spatial planning and to raise public awareness of flood issues. The flood warning map in the water cadastre shall contain: — areas of very rare floods involving floods with a return period of 50 years or more, — rare flooding areas involving floods with a return period of 10 to 20 years, — areas of frequent flooding involving floods with a return period of 2 to 5 years. The displayed polygons shall be equipped with a reliability assessment (1...minimum, 10... maximum reliability of the display, covering both the material reliability and the accuracy of the data capture). The flood warning map in the water cadastre also contains: flooding events. Other data on flood risk assessment in accordance with Article 7 of the Rules on the methodology for determining areas threatened by floods and associated erosion of inland waters and the sea and on the method of classifying land into risk classes (Official Gazette of the Republic of Slovenia, No. 60/07) are: — functional spill-over surfaces (the data layer of functional spreading areas shows flood surfaces intended for controlled spillage of water peaks, based on the characteristic surface in the reservoir or angle of the top of the barrier, as well as the outline of the DMV5-based contours or the DOF or TTN 5000 drawings. The layer is made on the basis of data from the available documentation of the IzVRS, DRSV and its concessionaires, studies, publications, articles, etc.), — flooding sections (data layer shows sections of watercourses that flood but their extent to which flooding is unknown is not known. The layer is made on the basis of data from the available documentation of the IzVRS, DRSV and its concessionaires, studies, publications, articles, etc.), — directions of flooding (layer shows directions of flood flow. The direction of the flood flow is the direction where the water flows from the watercourse or where the flow of water in the flood area is directed. The layer is made on the basis of data from the available documentation of the IzVRS, DRSV and its concessionaires, studies, publications, articles, etc.), — flooding areas (data layer contains areas of very rare floods (floods with a return period of 50 years or more) of the fluvial and pluvial type, which have been determined using a simplified hydrological-hydraulic model and based on available data on relief, land cover, precipitation and flows. The use of the data layer is suitable for cartographic representations on a scale of 1:50,000), — hydrological-hydraulic modelling areas for flooding areas (the data layer determines the boundaries of the areas of simplified hydrological-hydraulic models produced by applying effective precipitation to a two-dimensional computational grid running along the border of the hydrographic areas of the fourth and third levels, the border of the national territory, the border of more detailed watersheds or the hand-drawn boundary of model areas), — maps of flooding areas and hydrological-hydraulic modelling areas in PDF format showing flooding areas by river basin; and — flood hazard assessment reports for flooding areas in PDF format describing how flood risks are assessed by river basin.