Improving Sentinel
Asia’s Emergency
Response Activities:
SAR Data Analysis
and Mobile App
Development
Syams Nashrrullah
Angsana Chaksan
Geoinformatics Center - AIT1Outline• Summary of Sentinel Asia Activations and Generated
Maps/Products by GIC in 2022 and 2023
• SAR Data Analysis, with focus on Flood and Earthquake• Disaster Survey Mobile App• Case Study: Thailand Flood in 2021
2

SA Activation List in 2022
No.

Activation ID

Occurrence Date

Activation DateCountry

Disaster TypeNo. of Product12345678910111213141516171819202122232425262728434
435
436
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458*
459*
460
461*
462

15-Jan-2210-Feb-22
24-Feb-22
12-Apr-22
15-May-22
23-May-22
5-Jun-22
15-Jun-22
18-Jun-22
22-Jun-22
7-Jul-22
12-Jul-22
12-Jul-22
27-Jul-22
17-Aug-22
23-Aug-22
23-Aug-22
5-Sep-22
17-Sep-22
25-Sep-22
28-Sep-22
2-Oct-22
13-Oct-22
19-Oct-22
29-Oct-22
21-Nov-22
4-Dec-22
27-Dec-22

16-Jan-2211-Feb-22
3-Mar-2211-Apr-22
20-May-22
27-May-22
13-Jun-2221-Jun-22
23-Jun-22
27-Jun-22
7-Jul-22
13-Jul-22
13-Jul-22
27-Jul-22
18-Aug-22
23-Aug-22
24-Aug-22
5-Sep-22
18-Sep-22
25-Sep-22
26-Sep-22
9-Oct-22
15-Oct-22
19-Oct-22
29-Oct-22
22-Nov-22
5-Dec-22
27-Dec-22

Tonga
ThailandThailandPhilippines
India
Indonesia
Philippines
India
Bangladesh
Afghanistan
VietnamIndia
India
Philippines
Pakistan
Philippines
India
China
TaiwanPhilippines
Vietnam
Nepal
India
ThailandPhilippines
Indonesia
Indonesia
Philippines

Volcano-Tsunami
Oil Spill
Flood
Flood-Landslide
Flood
Flood
Volcanic Eruption
Flood
Flood
Earthquake
Flood-Landslide-StormFlood
Flood
Earthquake
Flood
Flood-Landslide-Storm
Flood
Earthquake
Earthquake
Flood-Landslide-Storm
Flood-Landslide-Storm
Ice-Hazard
Flood
Flood
Flood-Landslide-Storm
Earthquake
Volcanic Eruption
Flood-Landslide

213221122131226111* Escalated to International Disaster Charter (IDC) and project management by GIC-AIT3

SA Activation Summary in 2022
Volcano-Tsunami
4%● 28 Activations● 8 Types of disaster● 34 VAPs
Disaster type

Volcanic Eruption
7%

Earthquake
18%

Oil Spill4%
Ice-Hazard
3%

Activation

Earthquake

5

Flood

11

Flood-Landslide2Flood-Landslide-Storm

5

Ice-Hazard

1

Oil Spill

1

Volcanic Eruption

2

Volcano-Tsunami

1

Flood-LandslideStorm
18%

Flood-Landslide
7%

Flood
39%

Earthquake
Flood-Landslide-Storm
Volcanic Eruption

FloodIce-Hazard
Volcano-Tsunami

Flood-Landslide
Oil Spill4

SA Activation by Country in 2022
● 12 countries
8776

Number of Activation

6543332

2
10

1

1

Afghanistan Bangladesh

1

China

India

Indonesia

1

1

Nepal

Pakistan

1

Philippines

Taiwan1

ThailandTonga

VietnamCountry5

SA Activation List in 2023
No.
123456789101112
13
1415
16
17

Activation ID
463
464
465
467*
468*
469
470
471
472
473
474
475
476
477
478
479
480

Occurrence Date
6-Feb-23
16-Feb-23
28-Feb-23
6-Mar-23
14-May-23
14-May-23
27-May-23
15-Jun-23
8-Jun-23
13-Jul-23
18-Jul-23
20-Jul-23
25-Jul-23
5-Aug-23
4-Aug-23
27-Aug-23
12-Sep-23

Activation Date
6-Feb-23
17-Feb-23
1-Mar-23
7-Mar-23
11-May-23
14-May-23
25-May-23
14-Jun-23
14-Jun-23
13-Jul-23
17-Jul-23
26-Jul-23
28-Jul-23
8-Aug-23
16-Aug-23
30-Aug-23
13-Sep-23

Country
TurkeyPhilippinesPhilippines
Indonesia
Myanmar (Burma)
Bangladesh
Philippines
India
Kazakhstan
India
VietnamBhutanPhilippines
VietnamVietnam
Tajikistan
VietnamDisaster Type
Earthquake
Earthquake

No. of Product11111121-Oil Spill
Landslide
Storm
Storm
Flood, Landslide
Flood
Forest Fire
Flood
Flood
Flood
Flood
Flood
Landslide
Landslide
Flood, Landslide* Escalated to International Disaster Charter (IDC) and project management by GIC-AIT6

SA Activation Summary in 2023
Storm
12%

● 17 Activations● 7 Types of disaster● 9 VAPs
Disaster type

Activation

Earthquake

2Flood6Flood-Landslide

2

Forest Fire1Landslide

3

Oil Spill

1Storm2

Earthquake
12%

Oil Spill
6%

Landslide
17%

Flood
35%

Forest Fire
6%
Flood-Landslide
12%

Earthquake

Flood

Flood-Landslide

Forest FireLandslide

Oil Spill

7stromSA Activation by Country in 2023
● 10 countries
54

Number of Activation

44

3
2

2

1

1

1

Bangladesh

Bhutan11

1

Indonesia

Kazakhstan

Myanmar(Burma)

11

Tajikistan

Turkey0IndiaPhilippines

Vietnam

Country8

Disaster Maps and Products
Flood

Landslide

CycloneForest Fire

Volcano eruption

Earthquake

9Flood Mapping (SAR Data)
Method 1(Step using Raster Function in ArcGIS Pro) Radiometric calibration, Speckle
filtering, Coordinate transformation, Image differencing and Thresholding ofbackscatter changes.

Post-processing- Majority filter- Permanent watermasking- Manual cleaning- Merge results

Image differencing

Workflow for Detected Flood from ALOS-2

Post-processing

10Thresholding

Flood Mapping (SAR Data)
Method 2
Automatic Flood Mapping
https://github.com/chathumal93/ALOS2-Flood-Mapping••This repository includes an automatic statisticalbased flood mapping approach for ALOS2 Level
2.1 data. (Geometrically corrected andorthorectified data in .tif format).The below chart
gives a brief overview of ALOS2 L2.1 data.
The flood extraction process is carried out in a local
machine Jupyter Notebook with the help ofadditional data from the Google Earth Engine.

Flood Mapping (SAR Data)
Method 3
HydroSAR Approachhttps://github.com/fjmeyer/HydroSAR

OpenSARLab Platform
https://opensciencelab.asf.alaska.edu/
https://github.com/ASFOpenSARlab/open
sarlab-notebooks

The workflow of the Sentinel-1-based
processing chain in HydroSAR:
1. Image Geocoding and Calibration(RTC Processing),
2. Automatic and adaptive thresholdcalculation,
3. Initial flood map product,
4. Post processing to remove false
alarms using fuzzy-logic-basedclassification refinement,
5. Final flood map product including
the use of auxiliary data,
6. Data and product dissemination.

Disaster Maps and Products(Floods)
Flood in Pakistan, August 2022

Flood in Myanmar, May 2023

Flood in Vietnam, Jul 2023

13

Ground Deformation (SAR Data)
Method 1
GMT5SAR••

Flow diagram of 2-pass processing beginning with raw
SAR and orbital data and a digital elevation grid(dem.grd) and ending with geocoded grids ofinterferometric products.
There is a set of preprocessing codes for each of thesatellites – currently ERS-1, ERS-2, Envisat, Sentinel1, ALOS, and ALOS-2.

14

Ground Deformation (SAR Data)
Method 2
Geohazard Exploitation Platform (GEP)

https://geohazards-tep.eu/

15

Ground Deformation (SAR Data)
Method 3
ASF DAAC HyP3 using GAMMA software

https://search.asf.alaska.edu/#/16

Disaster Maps and Products(Earthquake)
Afghanistan, 30 Jun 2022

Indonesia, 18 July 2019

Philippines, 2 Aug 2022

17

Disaster Survey Mobile App• To collect information on the ongoingdisasters and their impact on important
objects, properties, and infrastructures.
Access using a web
link or QR Codehttps://arcg.is/1HWGWX0• Collected information will be useful fordisaster response and post-disaster
activities, including validating thesatellite-based disaster mapping
products from Sentinel Asia.
• Rapid data collection for quick disaster
info and the option to collect data for
more detailed damage assessment.

18

Disaster Survey Mobile App
Collected Info - Required
Main Data Collection
Required information

Description

Date/Time

Automatically shows the current date and time

Disaster Type••••Geotagged Photo

Possible to take up to 4 photos

Survey Location

Click ‘Find my location’ iconFlood,Landslide,
Earthquake,
Cyclone,•••Volcanic Eruption,
Forest Fire,
Otheron the app.

19

Disaster Survey Mobile App
Collected Info - Optional
Additional information

Description

Disaster Information

Depend on the selected disaster type, additional information about
the specific disaster can be added.
Flood

Landslide

Earthquake

Flood Type• Riverine Flood• Flash Flood••

Urban Flood
Coastal FloodLandslide Type• Mudflows• Rock Falls•

Debris Flows

Secondary Hazard• Tsunami• Liquefaction• Flooding••

Landslides
Fires20

Disaster Survey Mobile App
Collected Info - Optional
Additional information

Description

Disaster Information

Depend on the selected disaster type, additional information about
the specific disaster can be added.
CycloneVolcanic
Eruption

Secondary Hazard• Storm Surges• Strong Wind••

Tornadoes
Flooding

Secondary Hazard• Lava Flows• Lahars• Volcanic Gasses•••

Volcanic Ashes
Fires
Pyroclastic Flow

Forest Fire21

Disaster Survey Mobile App
Collected Info - Optional
Additional information

Description

Damage Information

Damage to assets such as building, road, bridge, and agriculture.
Building••••Road••••Building Type: Residential, Commercial,
Industrial, School, Hospital, Government,Religious, Cultural Buildings
Construction Material: Concrete, Masonry,Wood, Bricks
Number of Floor
Damage Level: Slightly Damage, Heavily
Damage, Completely Damage/Collapse
Road Type: Main Road, Secondary Road,Local Road
Construction Material: Concrete, Asphalt,Gravel, Earthen/Dirt
Impassable Road: Yes, No
Damage Level: Slightly Damage, Heavily
Damage, Completely Damage/Collapse

22

Disaster Survey Mobile App
Collected Info - Optional
Additional information

DescriptionDamage Information

Damage to assets such as building, road, bridge, and agriculture.
Bridge••••Agriculture••Bridge Type: Main Road Bridge, Secondary
Road Bridge, Local Road Bridge
Construction Material: Concrete, Steel,
TimberImpassable Bridge: Yes, No
Damage Level: Slightly Damage, Heavily
Damage, Completely Damage/Collapse
Crop Type: Rice, Wheat, Millet, Pulses,Cotton, Sugarcane, Tea
Damage Level: Slightly Damage, Heavily
Damage, Completely Damage/Collapse

23

“Thailand flood(2021 October)According to the Thailand Department of Disaster Prevention and Mitigation,
32 of the country’s 76 provinces have been affected by flooding during amonsoon season that has brought heavy rains for nearly a month.

24

Damage of the Disaster
●

●
●
●
●

Between September 27 and October 19, 2021, more than 13,600 square kilometers of thecountry were inundated and an estimated 1.3 million people were affected by the flooding,according to the Thailand Flood Monitoring Dashboard (GISTDA).
Thailand’s Disaster Prevention and Mitigation Department (DDPM) reported flooding hasaffected 58,977 households across 27 provinces.
In the north, Sukhothai province is the worst hit area with 7,392 households affected, mostlyin Sri Samrong, Khirimas and Muang districts, according to DDPM.
In the central region, severe flooding struck in Lopburi Province where 37,451 households
have been affected.
In early October, historical sites in Phra Nakhon Si Ayutthaya Province, home to many
temples and ruins, were flooded by the Chao Phraya River.

25

Disaster Maps and Products

ALOS-2 PALSAR-2 Data provided through Sentinel Asia Initiative was used to detect flood inPhichit, Sukhothai, Ayutthaya and, Supanburi Provinces.

26

DataCollection
Disaster Survey
Mobile Application

Aerial Survey Using Drones

https://arcg.is/1HWGWX027

28

Ground view of some of the affected areas

29

Aerial View of some of the affected areas

30Ground Data Viewer

31

Web Portal

Thailand Flood: https://gicait.maps.arcgis.com/apps/MapSeries/index.html?appid=bad36c78e5de4b4bb9a058f974912895
Disaster Response Portal: https://portal.geoinfo.ait.ac.th/portal/apps/sites/#/gic-ait-disaster-response-portal

32

Disaster Survey
Mobile Application
developed forSentinel Asia.

THANK YOU
Geoinformatics Center, Asian Institute of Technology