Entry Name: “CerebriAI-Wu-MC1”

VAST Challenge 2019
Mini-Challenge 1

Team Members:

Wenjie Wu, Cerebri AI, Inc, wenjie.jessie.wu@gmail.com PRIMARY

Zheng Zhou, Cerebri AI, Inc, zhengzhou.purdue@gmail.com

Yingjie Chen, Purdue University, victorchen@purdue.edu

Zhenyu Qian, Purdue University, qianz@purdue.edu

Student Team

No

Tools Used:

D3.js, React.js, Django, MySQL 

Approximately how many hours were spent working on this submission in total?

80

May we post your submission in the Visual Analytics Benchmark Repository after VAST Challenge 2019 is complete? 

Yes

Video

https://va.tech.purdue.edu/vast2019/mc1/HeatMosaic.mp4

URL

http://vast2019.zsazn.com/mc1

Questions

1.      Emergency responders will base their initial response on the earthquake shake map. Use visual analytics to determine how their response should change based on damage reports from citizens on the ground. How would you prioritize neighborhoods for response? Which parts of the city are hardest hit? Limit your response to 1000 words and 10 images.

If based on the earthquake shake map, the first responders would put higher priority on areas that are close to the epicenter. However, the provided earthquake shake map did not come with a timeline, so it failed to provide the changing patterns of three earthquakes and update the damages. Figure 1 clearly show the patterns and changes of the reported damage metrics from Safe Town (Area 4) in the three phases of the earthquake – fore-quake, main shock, and after-quake.

·        The first earthquake, a.k.a fore-quake, from April 6th 14:30 to April 6th 21:00, was light and it caused not much damage.

·        The second earthquake, main-quake, was the most serious one and it caused a number of damages and presumable casualties in most areas, happened between April 8th 8:30 to April 8th 17:00.

·        The third one was an after-quake also caused some damages and medical needs, happened approximate between April 9th 15:00 to 19:00, made condition worse in some area.

Figure 1 Report category heatmap from Safe Town (4) describing three earthquakes: fore-quake, main-quake, and after-quake

During the fore-quake period (April 6th, 14:30 ~ April 6th 21:00), from Figure 2 we can see that:

·        Area 3, 8, 9, 10, and 19 needed more urgent response for building damage.

·        Area 3, 5, 6, 9, and 11 needed higher priority of medical response.

·        Area 3, 9, and 11 needed higher priority power damage attention.

·        The road damage was reported high in area 3, 8, 9, 10 and highest in 13.

·        Sawyer and water leakage happened in area 3, 18, and 19.

Overall area 3 was the highest priority for first response during fore-quake period.

Figure 2 Reports aggregation for 19 locations during 1st earthquake (fore-quake) between 13:30 and 19:30 on April 6th

From Figure 3 (main-quake) we find that area 3, and 4 experienced strongest shake, followed by  7, 12, 14, and 18. The overall shake intensity appeared high in most areas and the reports were much more than from fore-quake.

Figure 3 Map view of the shake intensity during the main quake

 

Figure 4 Reports aggregation for 19 locations during 2nd earthquake (main-quake) between 08:00 and 14:00 on April 8th

It’s notable that power outage occurred in area 3, 8, 9, 10, and 11 because there has been no incoming report over a time span of ~12 hours for area 3, 8, and 9, ~20 hours for area 10, and ~2 hours for area 11, respectively (Figure 4).

Figure 5 Power outages in area 10, 11, 3, and 9 after 2nd earthquake (main-quake)

Meanwhile after these blank-report period we found a spike on the report values. We infer that such spike was due to the reports that people sent during these periods finally reached the server thanks power got restored (Figure 5).

For responding, the highest priority would be for area 10, 11, 3, then 8 and 9 as their power outage (10, 11, 3) started about 40 minutes (09:05 4/8) after the main-quake (~08:35 4/8) and the outage in area 8 and 9 began in ~4 hours (~12:30 4/8) after the main-quake. Except power outage, area 3 also had high severity reports on almost all other issues when it started. Besides, area 1, 7, 14, 17, 18 reported power issues but no outage (secondary priority).

Building-wise, all major areas reported damages. Area 9 and 8 was the most severe while several others (1, 3, 10, 11, 14, 18) also needed attention.

We received major medical reports from areas where hospitals are located (1, 3, 6, 9, 11, 16). We also assume there’s a medical facility in area 5 due to similar pattern, but the city’s introduction did not mention it. If no medical facility, area 5 would need immediate medical response. Area 8 has the most medical reports, followed by 4, 14, 15, 18. These areas would also need medical help as we can see a few serious reports. Medical team may need to send out to these areas with higher priority on area 8.

Area 8, 9 has the most road and bridge damages, followed by 3, 14, and 17.  Resources might need to repair these road damages.

Area 8, 9, and 14 reported serious water and sewer damages which would require prioritized response. Also 3, 16, 17 are the next ones need attention.

Overall area 8 would need highest priority of first response.

It’s also notable that the damage reports from area 1 were obviously diverted, including building, medical, power, and water. Considering area 1 is in a “not-felt” zone, as well as the doubtful uncertainties (see answer to question 2), we do not suggest list area 1 as top priority even it reported high values.

Figure 6 Reports aggregation for 19 locations during 3rd earthquake between 14:00 and 20:00 on April 9th

From Figure 5 above we can see after-quake caused area 3 and 8 lost power immediately. Area 3 experienced the longest 21-hour power outage from 15:00 April 9th to 12:00 April 10th. Area 8 and 14 also had a power outage. But at the middle there was a short period that power resumes supply in area 14 (see Figure 6).

Figure 7 Power outage pattern in Easton (14) after after-quake

 

From Figure 7 below we can also find area 14, then 4, then 12, then 17 experienced power outages starting ~02:00, ~7:00, ~10:00, and ~16:00 on April 10th, respectively.

Figure 8 Power outage in Easton (14), Safe Town (4), Pepper Mill (12), and Oak Willow (17) in hours after the after-quake

 

For the after-quake, area 16 has many reports at two modes. Many medium level reports as well as low severity reports. Area 13 appeared the same polarized pattern on power, road and bridge, and water and sewing.

 

Most areas had less severity reports during after-quake. But area 4’s condition got worse during after-quake. Therefore area 4 needed more resources during the after-quake period (see Figure 8).

 

Area 8, followed by 3, 9, and 11 experienced most severe water and sawing damage during after-quake, which would require higher attention (Figure 6).

 

For road and bridge, area 3, 8, 9, 10 had more damage during after-quake (Figure 6).

 

Building wise, area 3, 8, 9, 10 also had the most severe reports (Figure 6).

2.      Use visual analytics to show uncertainty in the data. Compare the reliability of neighborhood reports. Which neighborhoods are providing reliable reports? Provide a rationale for your response. Limit your response to 1000 words and 10 images.

 

For visualizing the uncertainty, we created a strip chart (Figure 9): the middle line of the strip is the mean value of each categories every hour, and the strips on the line are the reports. The height of the strips is twice of the standard deviation of that time calculated hourly. The color of each strip is a gradient heat color. Cool color means low severity, and warm color means high severity. The strips are semi-transparent (opacity: 0.1), so that when there are a lot of reports coming up in a short amount of time, the strips will overlay with each other and create a more solid area. Therefore, when we look at the strip chart, the wider the ribbon is, the larger the uncertainty is; solid area means large amount of reports, and the color of the ribbon indicate the severity.

Figure 9 expample of strip chart

Overall, area 2, 3, 6, 8, 9, and 15 have more wide and solid ribbons during all the categories and all the range during the peaceful time, which are recognized as high uncertainty. It seems that those are areas with larger population and their data have more noises. Figure 10 gives an example of large-population area 6 versus small-population area 13. Higher population might lead to higher density of buildings and more old buildings. We can observe that in area 3, 6, 8, and 15, the damages on the buildings during the aftershock were more severe than the mainshock.

Figure 10 6-downtown as an example of higher population and noises, and 13 – Cheddarford as an example of lower population and less noises

 

Areas 13 and 16 has polarized pattern through every category (Figure 6), which caused higher uncertainty during shake time. It may because the area cross two geological condition.

 

Area 1 is not reliable especially at the beginning time of the main earthquake. High severity reports suddenly disappeared. Also, these reports do not consistent with shake reports (Figure 11).

 

Figure 11 Palace hills has a pattern that a group of people reports high damage during the main earthquake, but not in the other two earthquakes

Due to power outage, area 3, 9, 10, 11 were not reliable at the time (Figure 5). It is possible to derive status during the power outage. But for area 3, it is impossible since the power outage was too long.

 

Areas 2, 5, 6, 15, 19 were complete and reliable. The values were not polarized, aligning with normal distribution (Figure 12 shows area 5).

Figure 12 Location 5 Southwest as an example of complete and reliable areas

 

Area 7 is not reliable since it has a small number of reports. Area 10 also has much less reports than other areas, but enough to present its conditions. Hence it is reliable (Figure 13).

Figure 13 Strip Chart of location 7 Wilson Forest and 10 Chapparal

Reporting period of area 12 is much longer (~6 hours) than other areas. When reports from other areas already calmed down, reports still arise from area 12 (see Figure 14).

Figure 14 Pepper Mill (12) reporting damage condition delayed

3.      How do conditions change over time? How does uncertainty in change over time? Describe the key changes you see. Limit your response to 500 words and 8 images.

 

Conditions in the area changed drastically over the time of the three earthquakes. Fore-quake was not severe, and it did not cause much damage. Main quake caused power outage in area 3, 8, 9, 10, and 11. After-quake caused less damage, for example, area 9 in Figure 15. But area 4 had more severe damage during after-quake (see Figure 16).

Figure 15 Damage condition in Broadview (9) less severe during after-quake than during main-quake

Figure 16 Damage level arisen in Safe Town between main-quake and after-quake

Uncertainty reduced over time, for example, in area 1, as the polarized pattern disappeared (see Figure 17).

Figure 17 Uncertainty changing over time in reports from Palace Hill (1)

In other areas, generally in the time periods between earthquakes (normal time), reports had a bigger variation range, but graduate decreased to a narrow range (in earthquake), for example, from Figure 18 we can see that in normal time the downtown area generates a lot of noisy reports which had large variance. During each earth quake, the noise got decreased for a great deal and reports’ reliability increased.

Figure 18 Overview Downtown (6) reports

For areas 4, 12, 13, 14, 15, 18, and 19 which has two or more poles on shaking reports, in the after-quake, they will switch to single mode and be more trustable. (Figure 19 shows the uncertainty condition change in East Parton (18))

Figure 19 East Parton uncertainty change

For a prolonged power outage, although all reports were collected at the end and can be used to derive the status during power outage, the temporal details are still missing. For example, in area 3, we cannot see when the report values decreased (the middle image in Figure 4).

 

4.      The data for this challenge can be analyzed either as a static collection or as a dynamic stream of data, as it would occur in a real emergency. Describe how you analyzed the data - as a static collection or a stream. How do you think this choice affected your analysis? Limit your response to 200 words and 3 images.

 

1.      Static collection allows us the see the whole picture. But from Dynamic stream, we cannot foresee data after current time.  The data after could help to check the reliability of current data. For example, in Area 1, at the beginning period of mainshock between 8:30am to 10:30am 04/08, there were a lot of severe reports happened. From a streaming report, we should send out first responder this area 1. But after a short while, these reports disappeared. We doubt these reports were sent out in panic.

 

Figure 20 Overview Palace Hills reports

2.      As static collection, we can see the max number of reports. We can easily use this number as a base to decide the color scale of heatmap. For stream analysis, we do not know the possible largest number. In our design, we adopted a dynamic color.

3.      For areas with power outage, in streaming mode, during the power outage period, we may assume their severity would remain the same as when they started to report. However, for some areas, e.g. area 3 and 8, when power came back, the accumulated messages have higher values. It seems the severity of the damage was increasing during the power outage period. Streaming mode may under estimate the severity.

Figure 21 Overview Old Town (3) and Scenic Vista (8)

4.      Typically, after-quake should be less than the mainshock and therefore less damage. Areas 15, 16, 17 etc. are in this pattern. However, for certain areas, e.g. 4 and 8, the damage is aftershock is severe than main-quake.  If we use the main-quake reports in streaming mode as a reference to predict the aftershock damage, we may underestimate the severity.

5.       

Figure 22 Condition worsen in Safe Town from main-quake to after-quake while condition better in Weston