100årsflöde

100årsflöde refers to a flood event with a statistical probability of occurring once every 100 years. It is a term commonly used in hydrology and flood risk management. This does not mean that such a flood will happen exactly once every century, but rather that the probability of a flood of that magnitude occurring in any given year is 1%. The concept is based on statistical analysis of historical flow data for a particular river or water body.

Calculating the 100-year flood is crucial for infrastructure design, such as bridges, dams, and flood defenses, as well as for land-use planning in flood-prone areas. Engineers and planners use these estimates to ensure that structures can withstand extreme events and to minimize potential damage and loss of life. However, it's important to note that climate change and altered land use can affect historical flow patterns, potentially making past estimates less reliable.

The 100-year flood level is a benchmark for flood risk assessment. Exceeding this level implies a more severe event than typically anticipated. Understanding and communicating the implications of such flood events are vital for public safety and effective disaster preparedness. While a 100-year flood represents a significant event, it is not the absolute maximum possible flood, and even rarer, more extreme events can occur.