Flood Mapping and Flood Hazard Mapping

Transcription

1 Flood Mapping and Flood Hazard Mapping P V Raju National Remote Sensing Centre Indian Space Research Organisation nrsc.gov.in

2 Flood Disaster Scenario: India nrsc Floods are the most frequent of all disasters that cripple India, in terms of loss of human lives, damage to property, annually. As per National Flood Commission estimates, about 40 million hectares of land is prone to floods. It is important to provide information during early warning, response, mitigation (hazard, bank erosion, etc) Satellite inputs are being used during all phases of flood management. Satellites helps in deriving precise information on extent of flooding, hazard, bank erosion, apart from flood forecasting and inundation modelling with other hydro-meteorological inputs. Kashmir Floods (2014), Uttarakhand Floods (2013), Assam Floods (2012), Bihar & Odisha Floods (2011), etc are some of the examples

3 Major Flood Events Ghaggar Floods-2010 Yamuna Floods-2010 Leh Flash Floods-2011 Jhelum Floods-2014 Kedarnath Floods-2013 Ganga Floods-2010 Kosi Breach Assam Floods-2012 Disasters cost India $10bn per year which includes more than $7 billion loss on account of floods. India has more of its annual GDP exposed to river flooding each year, on average, than any other country. Gujarat Floods-2005 Godavari Floods-2006 Krishna Floods-2009 Odisha Floods million hectares (mha) or nearly 1/8 of Indian geographical area is flood prone Annual average area affected by floods is about 7.57mha Affected crop area is about 3.5 mha. Average loss in financial terms is about Rs 13,000 millions. Indo-Gangetic & Brahmaputra river basins are most chronic flood prone areas.

4 Flood Disaster Management : Satellite Technology Near real time flood inundation mapping Flood hazard zonation: Assam, Bihar, Orissa & U.P Flood Forecast Modeling- Inundation Modelling Scientific assessment of Flood Prone Area River Morphological Studies & River Bank Erosion

5 Flood Response- Products State-Level Flood Map District-Level Flood Map Detailed Flood Map Flood Depth Maps Cumulative Flood Maps Flood Progr/Recess Maps Flood Persistence Maps

6 Dissemination nrsc DMS- VPN network NRSC website ( FTP process Bhuvan web portal (bhuvan.nrsc.gov.in) NDEM web portal (ndmcc.gov.in)

7 Floods

8 ASSAM FLOODS The first flood wave hit Assam on 02-June-2017 affecting Lakhimpur, Jorhat and Biswanath districts. NRSC analyzed Radarsat-2 SAR data of 03-June-2017 (0600hrs) and observed flood inundation in Lakhimpur, Jorhat, Biswanath, Cachar, Karimganj, Dhemaji and Hailakandi districts. About 91, 725 ha was observed to be inundated. The flood inundation information was disseminated to the concerned Nodal Ministries and Assam State Govt. departments. The following satellite images shows the flood situation in Assam. Dark signature denotes river and flood waters. Cyan color indicates the flood extent delineated from satellite data. Pre-flood situation Flood situation 03 Jun, 2017 Flooded Area Roads Railway Flood Inundation

9 MANIPUR FLOODS Floods were reported in Manipur on 02-June-2017 inundating low lying areas in Imphal, Thoubal and Bishnupur districts NRSC analyzed Radarsat-2 SAR data of 03-June-2017 (0600hrs) and observed flood inundation in Imphal, Thoubal and Bishnupur districts. About 8,714 ha is observed to be the inundated. The flood inundation information was disseminated to the concerned Nodal Ministries and Manipur State Govt. departments. The following satellite images shows the flood situation in Manipur. Pre-Flood Image Post-Flood Image Flood Map Imphal Flood Inundation Imphal Loktak Lake Loktak Lake

10 ASSAM FLOODS The first flood wave hit Assam on 02-June-2017 affecting Lakhimpur, Jorhat and Biswanath districts. NRSC analyzed Radarsat-2 SAR data of 03-June-2017 (0600hrs) and observed flood inundation in Lakhimpur, Jorhat, Biswanath, Cachar, Karimganj, Dhemaji and Hailakandi districts. The flood inundation information was disseminated to the concerned Nodal Ministries and Assam State Govt. departments. The following satellite images shows the flood situation in Assam.

11 Cyclone Phailin in Odisha Oct 2013 nrsc Daily Monitoring 12-hourly Monitoring

12 12-hourly Monitoring with RISAT-1 Baleswar, Odisha nrsc Severely affected districts like Balasore, were monitored on 12-hrly basis during peak floods and changes in inundated areas / village can be seen 13-Oct hours IST 14-Oct hours IST Baleswar Bay of Bengal Inundation 13-Oct hours IST Baleswar Baleswar Inundation Bay of Bengal Baleswar Bay of Bengal

13 Inundation as as on on 02nd 08Nov, 11Nov, 13 04Nov, Nov, Inundation recession during 2-4 Nov,1999 Inundation recession during 4-8 Nov,1999 Inundation recession during 8-11 Nov,1999 Inundation recession during Nov,1999

14 Severe floods were reported in Jammu & Kashmir during first week of September, Heavy rains coupled with rise in the water levels of Jhelum river had led to flooding in the districts of Anantnag, Pulwama, Badgam, Kulgam, Rajouri etc. DSC/ NRSC had mapped and monitored this event in near real time using satellite data from RISAT-1, RESOURCESAT-1 & 2, CARTOSAT-1 & 2 and other foreign satellite data. Value added products like flood inundation maps, persistence and recession maps, cumulative flood maps, annotated satellite image maps were generated and disseminated to MHA, NDMA, CWC, IMD and Govt. of J & K. The information was also uploaded on Bhuvan, NRSC and NDEM web portals. Floods in Jammu & Kashmir Sep 2014 nrsc n Pulwama Pampore Flood inundation as on 08-Sep-2014 overlaid on shaded relief map Galandhar Kakapora Awantipora Panjgam Flood Inundation River/Water Bodies Bijbehara

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17 Floods in Jammu & Kashmir IRS Resourcesat LISS-IV images showing flooding around Srinagar area Pre- Flood 3 During Flood 3 nrsc Inundation Mehjoor Nagar Ram Bagh Bund n Affected areas 1. Press colony; 2. Kothi Bagh; 3. Nohata; 4. Munshi Bagh; 5. Wazir Bagh; 6. Hazur Bagh; 7. Raj Bagh; 8. Maharajpur; 9. Jawahar Nagar ; 10. RamBagh; 11. Mehjoor Nagar; 12. K.P.Bagh ; 13. Padshahi Bagh

18 nrsc Floods in Jammu & Kashmir Bemina SDA colony Govt. Degree college CARTOSAT image showing flooding in Bemina area in Srinagar City as on 09-Sep-2014 Police Public school Housing colony Flooded River/Water n

19 Flood Forecasting & Flood Inundation Modeling FF & FIM constitutes important non-structural FM measures and given impetus by GOI during 12FYPEO derived inputs viz. LU-LC DEM/DTM, soil etc. are invaluable inputs for both flood forecasting & Flood inundation studies FF models: Godavari & Mahanadi developed, tested implemented in real-time Improved forecast lead-time, desirable accuracies in discharge estimation and the time of peak prediction at all critical points were demonstrated in real-time mode FF Development in progress for another critical 5 basins (Ghagra, Gandak, Kosi, Brahmini & Krishna) Paradigm shift from point to spatial flood early warnings -CWC is gearing towards development of spatial flood early warning systems NRSC, ISRO is planning to provide high resolution DEM s for all important & Critical flood prone areas and capacity building to states in HP-III project Capacity build at CWC through on the job training National and regional (state-wise) scientific assessment of flood prone area is underway with critical inputs from EO data.

20 Flood Early Warning Flood Inundation Modelling nrsc ALTM DTM Konta Kunavaram Simulation Results 23 Aug,2012 Time 06:00 Resoursesat-2 23 Aug,2012 Time 10:30 RESULT: Upto 90% accuracy Simulation Results 06-Aug-2013 Time 06:00 Radarsat-2 06-Aug-2013 Time 06:00

21 Flood Prone Area Assessment nrsc Flood Prone Area (Ver. 1.0) 1. Satellite Data - 10 years ( ) 2. Layer preparation (plains) based on 1. CWC HFL info for major rivers 2. NRSC Flood info for other areas Next Steps Hilly regions are to be included (which are not included in version 1.0) This will be addressed using Carto- DEM / ACE-SRTM and CWC HFLs Map showing the flood extent in various parts of the country Scientific assessment of Flood Prone Area Assessment in the country Apex Committee and Statewise Committees are formed Flood inundation extent Flood inundation (Kosi breach)

22 Flood Damage information system Flood inundation map... Road & Rail network Settlements Land use map Base map

23 Brahmaputra River Floods Villages affected in Marigaon district Flood damage statistics derived from RADARSAT SAR data of Jun, 2000 District No. of villages affected Area affected (Ha) Crop area affected (Ha) Dhemaji 73 5,658 3,611 Sibsagar ,000 7,436 Jorhat ,843 8,346 Lakhimpur ,857 16,636 Marigaon ,253 10,874 Darrang ,708 5,254 Nalbari 211 6,528 3,457 Goalpara ,668 10,510 Dhubri ,511 16, Flood inundation --- Pre-flood river course

24 Crop Area Submerged - Dhubri District, Assm Based on the analysis of RADARSAT SAR data of 10 th July 2002 LEGEND Cropped Area Submerged Crop

25 Flood Hazard Assessment Flood Hazard Atlas of Assam 10 years of satellite data ( ) Hazard based on frequency of flood occurrences 5 categories very low, low, moderate, high and very high Flood Risk Index for Nagaon District, Assam (Village as a unit) Village Flood Risk Index (VFRI) = Hazard Index * Vulnerability Index (VFRI ranges from 0 to 3) Hazard Index = Hazard Wt Vulnerability Index = (LU/LC Wt + Population Wt + Infrastructure Wt) Inputs and Weightages (Wt) Wt Flood Hazard No Hazard Low Very Low Moderate High Very High LU/LC Swampy, Marshy Others (plantations) - Cropped Population - < > 5000 Infrastruct ure - Other roads - Major roads

26 13 Years ( ) 128 satellite datasets Flood Mitigation Bihar Flood Hazard Atlas - Methodology Flood Hazard Map of Bihar nrsc Flood Hazard Index (Hazard Category (Hw) X Hazard Area (Aw)) X Intra Annual Variations (IAVw) Flood Hazard Index Top 10 Districts Hw = Weightage for Hazard Category Aw = Weightage for % Hazard Area IAVw = Weightage for intra annual variation

27 Data Used: 13 Years ( )- 128 satellite datasets. Approach: Based on Annual Frequency of Inundation and Intra Annual Flood Variations Bihar Flood Hazard Map Darbhanga Flood Hazard Map River/Water bodies River bank Major Roads

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29 Flood Mitigation: Flood Risk Assessment Flood Risk Index Map Flood Risk Index for Jagatsingpur District, Orissa Brahmaputra River Additional Inputs ALTM DTM Detailed census of :10K Database Flood Hazard. Nowgong Flood Frequency Flood Duration NEXT Flood Depth Legend River Low Risk (< 1) Moderate Risk (1-2) High Risk (2-3). Lankagaon Vulnerability Socio-Economic Info Infrastructure Land use / Land cover

30 Web Dissemination Flood Hazard Odisha State

31 Web Dissemination

32 Thank You