Duurlijnen

Duurlijnen, a Dutch term, translates to "duration lines" or "duration curves" and refers to graphical representations of how a quantity changes over time, specifically focusing on the duration for which a certain level is exceeded or maintained. These lines are commonly employed in fields such as hydrology, meteorology, and environmental engineering to analyze streamflow, rainfall, or pollutant concentrations.

A typical duurlijn plots the time duration on the x-axis and the corresponding value of the measured quantity on the y-axis. For instance, in hydrology, a streamflow duurlijn might show the number of days in a year that the river's discharge exceeded a specific flow rate. Conversely, it can also be used to show the duration for which the flow was below a certain threshold.

The primary utility of duurlijnen lies in their ability to provide a concise summary of extreme events and their frequency. They allow for quick comparisons between different time periods or different locations. For example, engineers might use duurlijnen to assess the risk of flooding by examining how long high flow rates persist. Similarly, environmental scientists might use them to understand the duration of drought periods or periods of elevated pollution. The interpretation of a duurlijn depends heavily on the context of the data being presented.