Risk identification

To understand the linkage between hazardous event and consequence it is useful to consider the common adopted Source-Pathway -Receptor-Consequence model. It is a conceptual tool for representing systems and processes that lead to a consequence. (E.g.: during a intense rainfall (source) the flood may deluge across the flood plain (pathway) and inundate housing (receptor) which can cause material damage (harm or consequence).)


is synonymous with hazard and refers to a situation with potential harm. The identification of possible danger (e.g. a natural event) is a task that belongs to experts.

Possible sources in case of flood events are:

  • Groundwater flooding: does predominantly occur in areas of chalk or limestone aquifers. This type of flooding affects older buildings at hillsides or basements which are at risk by groundwater flooding.
  • Flooding from overland flow: - can be caused by intensive rainfalls on saturated ground or on tarmac or concrete paved areas with inadequate drainage. Especially properties located in areas where floodwater accumulate, can be effected by this type of flooding. 
  • Blocked or overloaded drainage systems: can occur during intensive rainfall. This type of flooding is unpredictable and often appears unexpected. A drainage system includes open drainage ditches, culverts, buried drains and sewers. If flooding is caused by full sewers floodwater will be contaminated with sewage. Also contaminated water can flow back though sewers causing flooding inside buildings.

Further information can be found in chapter "flood probability assessment".

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Flood Risk Assessment






Further Information