Simulated output from SAVER

The data about time of each earthquake and the consequent emergency phases are omitted from the tables for clarity. DART data from the sensors is also omitted here but details are provided in Appendix G. For all scenarios, SAVER was able to link the incoming data to the expected descriptions from the domain ontology according to the rules and constraints defined for various phases and situations. The tables below show the simulated output from SAVER for each scenario. Situation awareness level 1 (SA1) in column 3, the comprehension of situation (SA2) in column 4, and the prediction (SA3) in column 5, are according to the SA requirements.

4.5.2.1 Scenario 1

Table 4.6 SAVER’s output from scenario 1 (Javed & Norris, 2011) Scenario

Number Emergency Phase SA1: Magnitude (M) Depth (D) Location (L) SA2 SA3 1 Pre- confirmation M = 8.1 D = 60 km L = 15N-115W High Magnitude Location is in water

Can generate tsunami!

1 Tsunami

confirmation Pre-decision

DART data from

sensor near source Wave height is very high near source Tsunami is generated

Potential tsunami threat!

1 Evacuation

decision DART data from all sensor until now Wave height is very high on all active sensors

Impact time:13hrs North-east of New Zealand

In Scenario 1, an earthquake of magnitude 8.1 is high enough to generate a tsunami and this magnitude data is simply classified as Level 1 SA data as it is a relevant piece of information for the understanding the situation. For SA Level 2, the magnitude data is interpreted as high enough to generate a tsunami. Similarly, data about the co-ordinates of the earthquake is also regarded as SA Level 1 since it is relevant to situation assessment in the current scenario, and SA Level 2 assessment interprets the co-

120 ordinates as an offshore or onshore location (offshore in this case). This information is combined using rules to generate Level 3 SA indicating that since the earthquake is high enough to generate a tsunami and the source is located offshore, it is likely to generate a tsunami. Therefore, SAVER’s suggestions on the first stage are accurate and promising. In the second stage of Scenario 1, data from the DART sensor close to the earthquake source confirms that there is a change in wave characteristics like height, amplitude etc., and this information qualifies as Level 1 SA since it is relevant to the understanding of the prevailing situation. This change in the wave information is interpreted as a tsunami generation and therefore tsunami generation is confirmed to provide Level 2 SA. Once, tsunami generation is confirmed, SAVER predicts a threat to the coastal areas as a Level 3 SA.

In the third stage of Scenario 1, data (SA Level 1) from DART sensors in the ocean shows how waves are propagating, i.e. direction and wave heights at different sensor locations that lead to an understanding of situations at those sensor locations providing Level 2 SA. This Level 2 SA, along with the knowledge of previous similar scenarios, becomes the basis for SA Level 3 SA to predict the expected arrival time of waves, height of largest waves and expected inundated areas.

4.5.2.2 Scenario 2

Table 4.7 SAVER’s output from Scenario 2 (Javed & Norris, 2011) Scenario

Number Emergency Phase SA1: Magnitude (M) Depth (D) Location (L) SA2 SA3 2 Pre- confirmation M = 6.8 D = 125 km L = 28S-107W Moderate Magnitude Location is in water

Can generate tsunami!

2 Tsunami

confirmation Pre-decision

DART data from

sensor near source Wave height is very high near source Tsunami is generated

Potential tsunami threat!

2 Evacuation

decision DART data from all sensor until now Wave height is very high on all active sensors

Impact time:11hrs North-east of New Zealand

121 In Scenario 2, earthquake magnitude data is Level 1 SA and once compared with rules, it generates SA Level 2 information i.e. earthquake magnitude is high and enough to generate a tsunami. Similarly, the source location co-ordinates of the earthquake comprise Level 1 SA data, which is transformed to Level 2 SA information that these co-ordinates point to an offshore location. Hence, all this information is combined and compared with rules to generate overall SA Level 3 information that the earthquake is of high magnitude and its source is located offshore and therefore it is able to generate a tsunami. Moreover, at the next stage of scenario simulation, DART data from the sensor closer to the earthquake source shows that there is a change in attributes of waves, therefore this change is interpreted as a tsunami to provide Level 2 SA. The confirmation of tsunami generation predicts the threat to the nearby coastal areas representing Level 3 SA information.

At the third stage of Scenario 2, data (level 1 SA) from DART sensors in the ocean shows a summary of the direction and height of waves at different sensor locations. The wave data is used to provide Level 2 SA i.e. understanding of the behaviour and propagation of waves at different sensor locations. To generate Level 3 SA, i.e. expected arrival time of waves, height of largest waves and expected inundated area, at different coastal areas information from Level 2 SA about direction of propagation, amplitude etc. is used along with the knowledge of previous similar scenarios.

4.5.2.3 Scenario 3

Table 4.8 SAVER’s output from Scenario 3 (Javed & Norris, 2011) Scenario

Number Emergency Phase SA1: Magnitude (M) Depth (D) Location (L) SA2 SA3 3 Pre- confirmation M = 3.9 D = 78 km L = 4N-171W Low Magnitude Location is in water Cannot generate tsunami! 3 Tsunami confirmation Pre-decision

DART data from

sensor near source Wave height is normal near source No tsunami threat!

3 Evacuation

decision DART data from all sensor until now Wave height is normal on all active sensors No impact, no threat!

In Scenario 3, earthquake attributes, i.e. magnitude, source location and depth are relevant to understand the tsunami situation (Level 1 SA data). The attributes perceived

122 in level 1 SA are compared using rules to generate SA Level 2 information i.e. earthquake magnitude is low and insufficient to generate a tsunami. Similarly, source location co-ordinates of earthquake are Level 1 SA data, which is transformed to level 2 SA information indicating that these co-ordinates point to an offshore location. All of this information is combined and compared with rules to generate overall SA Level 3 information i.e. although the earthquake source is located offshore; it has too low a magnitude to generate a tsunami.

Moreover, on the next stage of scenario simulation, DART data from the earthquake regions is still collected from the closest sensor to make sure that the tsunami is not generated declaring wave height is normal to present Level 2 SA. Therefore, no change in the DART data from the closest sensor infers that a tsunami has not been generated and so the Level 3 SA infers that there is no tsunami threat in the near future.

At the third stage of Scenario 3, data (SA Level 1) from all the DART sensors in the ocean provides a summary of wave attributes. Since no change in the behaviour of waves is observed, these DART sensors will remain inactive. This absence of activity is seen as no tsunami generation (level 2 SA) and therefore no possible threat (level 3 SA). 4.5.2.4 Scenario 4

Table 4.9 SAVER’s output from Scenario 4 (Javed & Norris, 2011) Scenario

Number Emergency Phase SA1: Magnitude (M) Depth (D) Location (L) SA2 SA3 4 Pre- confirmation M = 7.9 D = 60 km L = 21S-64W High Magnitude Location is on land Cannot generate tsunami! 4 Tsunami confirmation Pre-decision

DART data from

sensor near source Wave height is normal near source No tsunami threat!

4 Evacuation

decision DART data from all sensor until now Wave height is normal on all active sensors No impact, no threat!

In Scenario 4, incoming earthquake information is classified as Level 1 SA to give a summary of earthquake attributes i.e. magnitude, source location, and depth. These perceived attributes are compared using rules to develop Level 2 SA information i.e.

123 earthquake magnitude is high enough to generate a tsunami. In addition, the source location co-ordinates of earthquake (Level 1 SA data) are interpreted to develop Level 2 SA information that these co-ordinates point to an onshore location. Therefore, once this information is combined and compared using the rules, Level 3 SA is generated showing that the earthquake is located onshore, even though its magnitude is high; it cannot generate a tsunami.

On the second stage of scenario simulation, DART data from the earthquake regions is still collected from the closest sensor to make sure that a tsunami is not generated. In the current scenario, SAVER provides Level 2 SA that wave height is normal and no change in the DART data from the closest sensor infers that the tsunami has not been generated. Hence, at Level 3 SA, SAVER infers that there is no tsunami threat in the near future from the earthquake under consideration.

At the third stage of Scenario 4, data from all the DART sensors in the ocean provides a summary of wave attributes in the form of Level 1 SA. Like Scenario 3, since no change in the behaviour of waves is observed, these DART sensors remain inactive. This absence of activity is interpreted as no tsunami generation (Level 2 SA) by SAVER and therefore it is inferred that there is no possible tsunami threat (Level 3 SA).

In all the scenarios described above, SAVER has responded very well and as expected. It has successfully generated meaningful and useful interpretations of the incoming data. These interpretations are according to SA requirements and seem very promising to improve the decision making ability of emergency managers. More insight into the evaluation will be gained by the user evaluations in its actual use and are covered in the following chapters.

SAVER has effectively modelled situation information on two levels - 1) domain knowledge to infer what type of information is required to gain various levels of SA by considering the SA requirements, and, 2) transforming the actual information that is needed to achieve all levels of SA. Therefore, it has not only fruitfully classified incoming information but also provided accurate inferences. Since inference uses rules, these rules offer a reason for every classification or suggestion so that a user can understand how SAVER has reached its conclusions.

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