FLOOD ZONATION MAPPING USING GOOGLE EARTH ENGINE, A CASE STUDY OF ASSAM FLOOD 2022.

FLOOD ZONATION MAPPING USING GOOGLE EARTH ENGINE, A CASE STUDY OF ASSAM FLOOD 2022.

1. FLOOD ZONATION MAPPING USING GOOGLE EARTH ENGINE, A CASE STUDY OF ASSAM FLOOD 2022 Presented by - Bapan Basuli (UID-21143031024) Anurag Ghosh (UID-21143031026) Parth Mandal (UID-21143031038) Under the supervision of Ms. Payel Mani Dr. Arnab Kundu Department of Geoinformatics Pandit Raghunath Murmu Smriti Mahavidyalaya Bankura University Baragari, Jamboni, 722150 West Bengal Date 06.02.2023

2. CONTENT’S Introduction Research Object Study area Data required Methodology Software Using Result Conclusion

3. INTRODUCTION Floods are very serious, frequently occurring natural hazards that cause great damage to infrastructure, lives, and economies. Flood usually varies from place to place and depends on numerous factors such as its severity and time of occurrence. This study area flooded because heavy rainfall.

4. RESEARCH OBJECTIVE Analyzing and generating flood inundation map and calculating total affected areas. Estimataed crop affected flood extent and urban inundate areas. Estimate the total exposed population or suffferded people due to flood.

5. STUDY AREA This study area major river Brahmaputra. This area western part of assam. This area UTM location WGS 1984 46N. Lat 90 E TO 92 E & Lon 26N TO 27N. In June 2022 assam state floods affected some districts. The study area include at Bongaigon , Barpeta , Nalbari , Darrang , Goalpara , Kaprup and Marigona district in Assam.

6. DATA REQUIRED Sentinel 1 SAR Ground Range Detected VH polarization (10m) Hydro SHEDS DEM MODIS (Land use land cover 500m) Joint Research Center Surface water layer seasonality (30m) Joint Research Center Global Human Settlement Layer (250m )

7. METHODOLOGY WWF Hydro SHEDS DEM JRC Copernicus After flood Before flood Update mask (>5% slop area) Different threshold image Mask surface water Extra Refine Flood Pixel Resample pixel Update mask GHSL Update mask Crop Update mask urban Update mask population Calculated crop urban area Sum pixel population Sum pixels of affected crop & urban land Get number of people of effected MODIS LULC JRC POPULATION SENTINEL 1 SAR GRD DATA

8. SOFTWARE OF USING Microsoft office – this writing, graph, presentation. Google earth engine – Flood area mapping, pre & post SAR image analysis, modis landcover, GRC surface water, GRC Human Settlement Layer. ArcGIS – pre flood and post flood layout, Study area map.

9. IMAGE ACQUISITION INFORMATION AND SPECIFICATION Acquisition Time Acquisition Date Before Image 01 Jan 2022 to 30 Jan 2022 After Image 01 Aug 2022 to 30 Aug 2022 Observation Interferometric Wide Swath (IW) Mode Band C Swath 250 km Polarization VH Spatial resolution 5 m * 20 m

10. RESULT This research paper is all about the unpreceded and uncontrolled flood that occurred in East Assam due to heavy rainfall and all the dates are based on sentinel 1 GRD data, SAR image. Before-flood:01/01/2022 to 30/01/2022 & After flood:01/08/2022 to 30/08/2022.

11. SENTINEL-1 SAR IMAGE

12. DIFFERENCE LAYER

13. DISCUSSION Estimated flood extent area 188681 hectares. Estimated number of exposed people 1184451. Estimated affected urban areas 324 hectares. Estimated affected crop areas 61032. Estimated flood extent 188681 hectares. The storm in Assam caused massive damage to standing crops, vegetation, thousands of trees were uprooted, and power and water supply was interrupted in the Assam. Many in the district have lost their entire homes as well.

14. FLOOD EFFECT AREA

15. AFFECTED CROP LAND

16. CONCLUSION In this study area use SAR data. SAR data are collected from Copernicus using google earth engine. Flood monitor occurred in assam June 2022. SAR data polarization VH before flood and after flood. Flood area monitor using subtract after flood to before flood

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