Tracer simulations for an Assessment of Risk Exposure
Interactive Representation of Simulated Risk Exposure (German Bight)
Graphical User Interface for the Assessment of Risk Exposure
A realistic drift statistics for the southern North Sea was established for the period 1958-2003. Assuming a constant frequency of illegal oil releases, a large number of simulations (hypothetical oil spills) at different locations was initialized with constant time lags between them. The resulting set of simulations describes both the mean risk exposure of different coastal areas and corresponding variability. An interactive graphical user interface was developed that allows for an interactive exploration of how simulated results depend on parameters like location of the spill, wind direction, wind speed, season of the year, or assumed half-life of the hypothetical pollutant.
Simulations for the Southern North Sea
Relative significance of hypothetical oil spills for the German North Sea coast (drift based).
The figure on the right illustrates threats that emanate from hypothetical oil spills in different southern North Sea regions.
Relative sizes of circles represent relative probabilities of the German coast being affected by an assumed release at the respective location. Pie charts resolve the allocation of risks among the five colour coded coastal areas.
The graph does not take into account that the probability of occurrence of an oil release will generally depend on ship density. If the probability of illegal oil dumping is assumed to be proportional to ship density, the regions off the Dutch coast or near the English Channel gain in importance for the analysis. The distribution of risk among different coastal regions, however, remains independent of such an assumption.
More details about the scientific study the figure comes from can be found in the two publications listed below.
- Chrastansky, A. and U. Callies, 2009: Model-based long-term reconstruction of weather-driven variations in chronic oil pollution along the German North Sea coast. Marine Pollution Bulletin 58, 967-975.
- Chrastansky, A., Callies, U. and D. M. Fleet, 2009: Estimation of the impact of prevailing weather conditions on the occurrence of oil-contaminated dead birds on the German North Sea coast. Environmental Pollution 157, 194-198.