FLOOD S AND FLASH FLOOD S

1. FLOODS AND FLASH FLOODS M.P.Singh Superintending Engineer Hydrological Observation Circle Central Water Commission, Guwahati

2. FLOODS FLOODS ARE NATURAL PHENOMENA.

3. FLOODS • FLOODS ARE WATER RELATED DISASTER • WATER RESOURCES MANAGEMENT INCLUDES MANAGEMENT OF THESE DISASTERS

4. CAUSES OF FLOODS • PRECIPITATION • INADEQUATE CAPACITY (WITHIN BANKS) • BANK EROSION AND SILTING • LAND SLIDES • TIDAL AND BACK WATER EFFECTS • POOR DRAINAGE • SNOW MELT AND GLACIAL OUT BURSTS

5. INDIA FLOOD MANAGEMENT AREA (M. Ha) GEOGRAPHICAL 328 FLOOD PRONE 40 12% PROTECTABLE 32 80% PROTECTED 16.4 45% FLOOD AFFECTED • AVERAGE 7.7 • MAXIMUM 17.5 (1978) • MINIMUM 1.5 (1965)

6. INDIA FLOOD MANAGEMENT FLOOD PRONE AREA - 40 M.Ha. WEST BENGAL 7.91% ASSAM 9.40% BIHAR 12.71% ORISSA 4.18% UTTAR PRADESH 21.90% OTHER STATES 43.9%

7. INDIA FLOOD MANAGEMENT AREA AFFECTED BY FLOODS - 1953-99 AREA IN M.Ha. 1999 YEAR

8. FLOOD DAMAGE IN INDIA DURING 1953-2000 RUPEES IN CRORE YEAR

9. INCREASED VULNERABILITY CAUSES • INDISCRIMINATE ENCROACHMENT • INCREASING ECONOMIC AND DEVELOPMENTAL ACTIVITIES IN FLOOD PLAINS • LACK OF REGULATIONS • INADEQUATE DRAINAGE SYSTEM • INADEQUATE MAINTENANCE • LACK OF DISASTER PREPAREDNESS

10. FLOOD MANAGEMENT APPROACH • FLOODS CAN NOT BE ABSOLUTELY CONTROLLED • FLOODS CAN ONLY BE MANAGED TO REDUCE FLOOD LOSSES

11. FLOOD MANAGEMENT STRATEGIES • MODIFY THE FLOODS • MODIFY THE SUSCEPTIBILITY TO FLOOD DAMAGE • MODIFY THE LOSS BURDEN • BEAR THE LOSS

12. FLOOD MANAGEMENTORGANISATIONS • STATE FLOOD CONTROL DEPARTMENTS • CENTRAL WATER COMMISSION • GANGA FLOOD CONTROL COMMISSION • BRAHMAPUTRA BOARD • MHA - NDM DIVISION

13. FLOOD MANAGEMENTMEASURES • STRUCTURAL : PHYSICAL WORKS FOR MEASURES MODIFYING FLOOD MAGNITUDE ( TO KEEP FLOODS AWAY FROM PEOPLE ) • NON-STRUCTURAL : PLANNED ACTIVITY TO MODIFYMEASURES SUSCEPTIBILITY TO FLOOD DAMAGE ( TO KEEP PEOPLE AWAY FROM FLOODS )

14. FLOOD MANAGEMENT STRUCTURAL MEASURES • DAMS & RESERVOIRS • EMBANKMENT • CHANNEL IMPROVEMENT • RIVER DIVERSION • INTER BASIN TRANSFER • ANTI EROSION WORKS

15. FLOOD MANAGEMENT NON STRUCTURAL MEASURES • FLOOD FORECASTING & WARNING • FLOOD PLAIN ZONING • FLOOD FIGHTING • FLOOD PROOFING • FLOOD INSURANCE • RELIEF & REHABILITATION

16. FLOOD PLAIN ZONING WATER SUPPLY III III II I II I FACTORY HOSPITAL GOVT. OFFICE POWER HOUSE PARK RESIDENTIAL AREA UNIVERSITY FREQUENT FLOOD FLOOD ONCE IN 25 YEARS NORMAL CHANNEL FLOOD ONCE IN 100 YEARS

17. FLOOD PLAIN ZONING WARNING RESTRICTIVE PROHIBITIVE RESTRICTIVE WARNING I II III II I RIVER CHANNEL

18. FLOOD FORECASTING INDIA BEGINNING • STARTED BYCENTRAL WATER COMMISSION • YEAR 1958 • RIVER YAMUNA • FORECASTING STATIONDELHI RAILWAY BRIDGE

19. FLOOD FORECASTING AND WARNING STEPS • DATA COLLECTION • DATA TRANSMISSION • DATA ANALYSIS & FORECAST FORMULATION • DISSEMINATION OF FORECAST

20. FLOOD FORECASTING DATA COLLECTION • HYDROLOGICALRIVER WATER LEVEL RIVER DISCHARGE • HYDROMETEOROLGICALRAINFALL OTHER RECIPITATIONeg. SNOW, HAIL ETC.

21. FLOOD FORECASTING DATA TRANSMISSION • WIRELESS • TELEPHONE • FAX • SATELLITE • TELEGRAPH • TELEX

22. FLOOD FORECASTING DATA ANALYSIS & FORECAST FORMULATION • CORRELATION • MATHEMATICAL MODELS

23. FLOOD FORECASTING DISSEMINATION CIVIL AUTHORITY FORECAST OTHER AGENCIES PRESS, A I R DOORDARSHAN OTHER USERS LOCAL REPRESENTATIVES

24. FLOOD FORECASTING AND WARNING PRESENT SYSTEM - SCHEMATIC DIAGRAM RIVER STAGE & DISCHARGE AT BASE STATION RIVER STAGE & DISCHARGE AT FORECASTING STATIONS WEATHER FORECASTS RAINFALL REGIONAL OFFICES OF I.M.D. REGIONAL OFFICES OF I.M.D. F.M.O OF I.M.D F.M. O. OF I.M.D FLOOD FORECASTING CENTRES & CONTROL ROOMS FORMULATION OF FORECAST C.E., S.E. MINISTRY OF WR CWC HQ CIVIL AUTHORITIES PRESS RADIO STATE GOVT. CONTROL ROOM ENGG. AUTHORITIES P & T DOORDARSHAN DEFENCE INDUSTRIES POLICE FLOOD COMMITTEE RAILWAYS

25. FLOOD MANAGEMENTscope • Use of Remote Sensing and GIS • Research and Development • Weather / Rainfall Forecasting • FF Modelling • Capacity Building • International Cooperation

26. FLOOD FORECASTING NETWORK INDIA • COVERS MAJOR AND INTER STATE RIVER BASINS. 166 STATIONS:- INFLOW 27 &STAGE 139

27. FLOOD FORECASTING STATIONS INDIA 85 27 17 15 9 8 3 2 GANGA B’PUTRA GODAVARI WEST FLOWING EASTERN RIVERS KRISHNA MAHANADI BARAK

28. FLOOD FORECASTING STATIONS INDIA 35 32 23 15 14 11 11 6 4 4 3 2 2 2 1 UP NCT DELHI BIHAR AP W. B. MP ASSAM ORISSA UTTAR ANCHAL D & NH GUJARAT HARYANA M’RASHTRA JHARKHAND KARNA TAKA

29. FLOOD MANAGEMENT ACTIVITIES During flood Pre flood Post flood

30. FLOOD PLAIN ZONING CONCEPT • AN IMPORTANT NON-STRUCTURAL MEASURE. • REGULATES LAND USE IN FLOOD PLAINS TO RESTRICT DAMAGE BY FLOODS. • INVOLVES DEMARCATION OF ZONES IN FLOOD PLAINS COMPATIBLE WITH FLOOD RISKS INVOLVED.

31. FLOOD PLAIN ZONING ZONE REGULATION PRIORITY - I ACTIVITY LIMITED TO WATER LEVELS CORRESPONDING TO 100 YEARS FLOOD FREQUENCY AND DRAINAGE CONGESTION FOR 50 YEARS RAINFALL.

32. FLOOD PLAIN ZONING ZONE REGULATION PRIORITY - II ACTIVITY LIMITED TO LEVELS CORRESPONDING TO 25 YEARS FLOOD FREQUENCY AND DRAINAGE CONGESTION FOR 10 YEARS RAINFALL FREQUENCY.

33. FLOOD PLAIN ZONING ZONE REGULATION PRIORITY - III LESS ECONOMIC AND COMMUNITY ACTIVITY IN AREAS VULNERABLE TO FREQUENT FLOODS.

34. FLOOD MANAGEMENTFUTURE STRATEGIES • Focused Approach • Basin Wise Action Plan • Flood Plain Zoning • Role of Central Government • Funding of Planned Flood Management Works • Adequacy of Flood Cushion in Reservoirs

35. THANK YOU