Chapter 4
Testing and Validating Against Historic
Spills
Abstract To validate the predictive capability of ERA Acute, a study was carried
out using data from two well-studied historic oil spills, the Exxon Valdez Oil Spill
(EVOS) and the Deepwater Horizon Oil Spill (DHOS) incidents. Results from the
case studies with ERA Acute were compared to the impact estimates and recovery
observations that have been reported in the extensive research following the two
incidents. Resource data relevant for each of the two incidents were reconstructed
within the analysis area. Performance boundaries were set up for evaluating the ERA
Acute results, based on the ranges of the impact and recovery estimates reported in
the post-spill assessments. Validation of an oil spill ERA model against post-spill
assessments of historic spills is a challenging exercise due to scientific limitations of
both. ERA Acute performed satisfactorily compared to the performance boundaries
and the study gave useful insight into the predictive capabilities of ERA Acute. The
results from the study were used to evaluate between two different impact models
and to increase the individual vulnerability of cetaceans.
Keywords Model validation · ERA Acute validation · ERA Acute case studies ·
Impact validation · Exxon Valdez oil spill · Deepwater Horizon oil spill
4.1 Method of Validation Against Historic Spills
An ERA Acute assessment has been performed for two historic oil spill incidents. The
study was performed according to the standard procedure of a regular environmental
risk analysis (ERA) for exploration wells on the NCS (OLF 2007) using the ERA
Acute methodology (cf. Fig. 1.6). The aim of the assessment was to compare ERA
Acute results with damage estimates from post spill assessments from historic oil
spill incidents, where such estimates are derived from observed and reported impacts.
Required input data to perform the validation study were: (1) analysis areas and
grids, (2) damage assessment from field observations, (3) pre-defined performance
boundaries (4) oil drift statistics from stochastic modelling and field observation, (5)
VEC datasets.
© The Author(s) 2021
C. Stephansen et al., Assessing Environmental Risk of Oil Spills with ERA Acute,
SpringerBriefs in Environmental Science,
https://doi.org/10.1007/978-3-030-70176-5_4
59
Testing and Validating Against Historic
Spills
Abstract To validate the predictive capability of ERA Acute, a study was carried
out using data from two well-studied historic oil spills, the Exxon Valdez Oil Spill
(EVOS) and the Deepwater Horizon Oil Spill (DHOS) incidents. Results from the
case studies with ERA Acute were compared to the impact estimates and recovery
observations that have been reported in the extensive research following the two
incidents. Resource data relevant for each of the two incidents were reconstructed
within the analysis area. Performance boundaries were set up for evaluating the ERA
Acute results, based on the ranges of the impact and recovery estimates reported in
the post-spill assessments. Validation of an oil spill ERA model against post-spill
assessments of historic spills is a challenging exercise due to scientific limitations of
both. ERA Acute performed satisfactorily compared to the performance boundaries
and the study gave useful insight into the predictive capabilities of ERA Acute. The
results from the study were used to evaluate between two different impact models
and to increase the individual vulnerability of cetaceans.
Keywords Model validation · ERA Acute validation · ERA Acute case studies ·
Impact validation · Exxon Valdez oil spill · Deepwater Horizon oil spill
4.1 Method of Validation Against Historic Spills
An ERA Acute assessment has been performed for two historic oil spill incidents. The
study was performed according to the standard procedure of a regular environmental
risk analysis (ERA) for exploration wells on the NCS (OLF 2007) using the ERA
Acute methodology (cf. Fig. 1.6). The aim of the assessment was to compare ERA
Acute results with damage estimates from post spill assessments from historic oil
spill incidents, where such estimates are derived from observed and reported impacts.
Required input data to perform the validation study were: (1) analysis areas and
grids, (2) damage assessment from field observations, (3) pre-defined performance
boundaries (4) oil drift statistics from stochastic modelling and field observation, (5)
VEC datasets.
© The Author(s) 2021
C. Stephansen et al., Assessing Environmental Risk of Oil Spills with ERA Acute,
SpringerBriefs in Environmental Science,
https://doi.org/10.1007/978-3-030-70176-5_4
59