Flooding - probability of primary and regional floods (2020)

Description

Since 2019, the DPRA has been recommending the new map ‘Local Flood Probability’ for the Flood Consequence Reduction theme. The map provides insight into the probability of a flood occurring with a water depth > 20 cm and thus gives a better insight into flood risks than only the maximum water depth maps, which only present the ‘scarce image’ of the maximum water depths (the most extreme event). The ‘place-based flood probability’ will therefore help in the theme of Reducing the Effect of Floods. The primary barriers protect the hinterland from flooding. These barriers have a standard that indicates what the probability of failure may be per dike section. On the basis of these standards, the flood scenarios are derived and have an exceedance frequency that is equal to or less than the standard. It is possible that certain locations in the hinterland may be affected by more than one flooding scenario. When this happens, the chance increases that these specific locations will be affected by a flood. Hence the name localized flood probability. The site-specific flood probability map is made up of scenarios after the primary flood defences have been breached. This is compiled from the primary flood images from the National Flood Data Database (the source database for flood scenarios in the Netherlands). For this purpose, only ROR (Flood Risk Directive) scenarios were used with the frequency of exceedances that correspond to the standards of the corresponding standard of the dike sections. Some parts of the map do not correspond to the flood image of primary embankments. This is because some scenarios have been archived and could not be taken into account for the development of this map.

Resources

Name Format Description Link
34 https://geodata.zuid-holland.nl/geoserver/klimaat/wms?service=WMS&version=1.1.0&request=GetMap&layers=klimaat%253AOverstromingskans_primaire_en_regionale_keringen&bbox=43662.5%252C406692.0%252C130481.0%252C483120.0&width=768&height=676&srs=EPSG%253A28992&format=image%252Fpng

Tags

  • klimaateffectatlas
  • overstroming
  • primaire-waterkeringen

Topics

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