Floods management
- 1. Flood Management Dr. Kailash Gupta M. Tech. (Disaster Assessment & Mitigation) class, November 12, 2013 Malaviya National Institute of Technology, Jaipur 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 1
- 2. Outline • Significance of Flood Management • Types of Floods • Causes of Floods • Vulnerability to Floods in India • Effect of Floods • Flood Management Plan • Flood Forecasting and Warning • Flood Mitigation • Case Studies • References 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 2
- 3. Significance of Flood Management • Floods always have been constant companion of humanity • Increasing trend of hydro-metrological disasters in numbers, intensity, and complexity • ~ 75% of deaths and property damages occur due to hydro-metrological disasters internationally • ~ 75% deaths occur due to drawing in floods internationally • ~ 75% deaths due to disasters occur in South-East Asia • Disasters have political significance, i.e. creation of Bangladesh • India is one of the most flood prone countries of the world 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 3
- 4. Significance of Flood Management (Cont.) • In India on an average 1,588 people died, 3 cr. affected, 12 lakh houses damaged, and Rs. 1805 cr. loss per year during 1953 to 2005 • Article 21 of the constitution, “No person shall be deprived of his life . . .” 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 4
- 5. Flood • A flood is an overflow of water that submerges land which is normally dry • Periodic floods occur on many rivers, forming a surrounding region known as the flood plain. 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 5
- 6. Types of Floods Areal (rainfall related) • Floods can happen on flat or low-lying areas when the ground is saturated and water either cannot run off or cannot run off quickly enough to stop accumulating. • Floods can also occur if water falls on an impermeable surface, such as concrete, paving or frozen ground, and cannot rapidly dissipate into the ground. Riverine • The increase in flow may be the result of sustained rainfall, rapid snow melt, monsoons, or tropical cyclones. • Localized flooding may be caused or exacerbated by drainage obstructions such as landslides, ice, or debris. 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 6
- 7. Types of Floods (Cont.) Flash floods Occur due to intense thunderstorms or sudden release from an upstream impoundment created behind a dam, landslide, or glacier. Snow-melt floods Monsoon floods Cyclone floods Floods due to dam burst/ failure Urban floods 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 7
- 8. Causes of Floods • Heavy rainfall • Inadequate capacity of rivers to carry the high flood discharge • Inadequate drainage to carry away the rainwater quickly to stream / rivers • Ice jams or landslides blocking streams • Cyclones • Poor permeability of the soil • Dam (including gate opening), levees, retention ponds, or any water retaining structure breakage • High accelerated snow melting 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 8
- 9. Causes of Floods (Cont.) • Highly silted river system • Steep and highly erodible mountains • Monsoon concentration in June – Sept. • Unusual high tides • Tsunamis • Exceeding of water flow rate compared to the capacity of the river channel, particularly at bends or meanders in the waterway 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 9
- 10. Vulnerability to Floods in India • 23 out of 35 states and union territories are vulnerable to floods • Major flood prone states are Assam, Bihar, West Bengal, UP, and Orissa • Major flood prone basins are Ganga, Brahmaputra, and Mahanadi • 40 m hectares, constituting 12% of land in India is vulnerable to floods and river erosion • Women and children are more vulnerable to floods • Most deaths occur due to drowning • (Govt. of India, 2012) 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 10
- 11. Effects of Floods Primary Effects • Loss of life • Infrastructure damage, including buildings, bridges, sewerage systems, transport, and electricity facilities, that affect relief, communication, and drinking water • Agriculture • Water born diseases Secondary and Long-term Effects • Post-traumatic stress disorder • Livelihood 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 11
- 12. Flood Management Plan • Flood management means methods to reduce or prevent the detrimental effects of flood • National Flood Control Program started in 1954 • Flood Management Program of Ministry of Water Resources, GOI is to assist states for river management, flood control, anti-erosion, drainage development, flood proofing, restoration of damaged flood management works, and anti-sea erosion • XI Plan (2007-12) had 406 schemes in 19 states with outlay of Rs. 8,000 crs. and 80% funding by GOI. Rs. 7,575 invested • Recommendation for XII Plan, Rs 16,000 crs. • Central Water Commission is the nodal agency • Indian Metrological Department • ISRO - sensors platform, provide satellite data, monitors real-time impact of extreme weather, R&D for improvement. Flood inundation mapping to MHA and states. In 2013, 109 maps were created 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 12
- 13. Flood Management Plan (Cont.) • Annual Conference of Relief Commissioners/ Secretaries of Disaster Management of States/ UTs to Review States of Preparedness for South-West Monsoon. This is year it was on May 14, 2013, in Vigyan Bhawan, New Delhi • In Rajasthan, CM chairs a (Video) conference with Secretaries of relevant departments and Collectors • In Rajasthan districts, Flood Control Cells are created during monsoon • In Jaipur, Flood Control Cells were created at Banipark, Ghat Gate, and Mansorver with sandbags, labor, mud pumps (12), earth-moving equipment. Officers were posted round the clock 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 13
- 14. Flood Forecasting and Warning • Indian Metrological Department forecasts rains • District level forecasts on the webpage for all 604 districts, including thunder storm warning • Every Friday 2 week qualitative outlook • 215 cities forecast for 7 days • Weather warning 3 days in advance • 15 Doppler weather radars are used, one of them at Jaipur • 10 Flood Metrological Offices 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 14
- 15. Flood Forecasting and Warning (Cont.) • CWC started flood forecasting in 1958 • About 6,000 flood forecasts issued during monsoon every year • 166 Flood Forecasting Centers of CWC (134 level forecasting & 32 inflow forecasting) • Flood forecast and warning dissemination on http://india-water. gov.in, apart from special messengers, telephone, Fax, wireless, emails, SMS, and media • IMD claims rain forecast is 95% accurate • CWC claim flood forecasting is 98% accurate (forecast water level is within 15 cm of actual water level of the inflow forecast and is within 20% of actual discharge) • Then why 1,588 people die every year due to floods? 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 15
- 16. Flood Mitigation • National Flood Risk Mitigation Project – “This project aims to mitigate consequences of floods by improving capacity for effective preparedness, promptness in response and to assess the risk and vulnerabilities associated with floods” (Government of India, 2011. p. 25). NDMA to prepare DPR 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 16
- 17. Flood Mitigation: Structural Measures Short Term • Inspection and maintenance of structures, embankments, and flood walls • Channel improvement • Drainage clearance • Diversion of flood water 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 17
- 18. Flood Mitigation: Structural Measures (cont.) Long Term • Adequate no. of raised platforms and shelters with amentias • Dams and reservoirs • Embankments, flood walls, sea walls • Natural detention basins • Channel improvement • Drainage improvement • Diversion of flood water • Flood-safe public utility installations 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 18
- 19. Flood Mitigation: Non-structural Measures Short Term • Insurance cover • Public awareness about health problems and illness Long Term • National Flood Atlas has been prepared by the CWC • Flood forecasting model of the Godavri Basin prepared and real-time simulation is done • Flood plain zoning • Removal of human encroachments from flood plains • Depopulating the flood plains • Afforestation 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 19
- 20. Flood Mitigation: Non-structural Measures (Cont.) • Early warning • Rainfall forecast with place, time, and intensity for stakeholders to take preparedness measures • Availability of forecast with ability to action by public. Last-mile connectivity • Coordination mechanism within states with CWC, IMD, ISRO . . . • Public awareness • Professional training • Floodplain Management Association, US has certificate program • In US all flood plains have been mapped. • In US it is compulsory to take flood insurance for mortgage 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 20
- 21. Case Studies • 1981 Jaipur Amanisha Nalah flood • 2004 Tsunami - floods • 2005 Vadodara floods • 2005 Mumbai floods • 2006 Barmer floods • 2013 Uttarakhand floods 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 21
- 22. References • Central Water Commission. (May 2013). Flood forecasting and warning mechanism. Presentation at the Annual Conference of Relief Commissioners/ Secretaries of Disaster Management of States/ UTs to Review States of Preparedness for South-West Monsoon. New Delhi: Government of India, Ministry of Home Affairs • Govt. of India, Ministry of Home Affairs. (2008). National disaster management guidelines: Management of floods. New Delhi: Author • Govt. of India, Ministry of Home Affairs. (2011). State level programmes for strengthening disaster management in India: Initiatives by Ministry of Home Affairs, GoI. New Delhi: Author • Govt. of India, Ministry of Home Affairs. (2012). Disaster management in India. New Delhi: Author • Gupta, A. K. (June 2013). Floods: causes, consequences and management. Presentation at the State Level Workshop on Flood Management. Jaipur: HCM Rajasthan State Institute of Public Administration • Indira Gandhi National Open University. (2005). Understanding natural disasters. MPA-001. New Delhi: Author • Kaushik, A. D. (2012). Flood risk mitigation and management: A training of trainers (TOT) module. New Delhi: National Institute of Disaster Management • Yadav, B. P. (May 2013). Forecasting of Southwest monsoon 2013, cyclone warning services and IMD’s future plans for enhancement of its forecasting capabilities. Presentation at the Annual Conference of Relief Commissioners/ Secretaries of Disaster Management of States/ UTs to Review States of Preparedness for South-West Monsoon. New Delhi: Government of India, Ministry of Home Affairs 27-Sep-14 Gupta, Flood Management, MNIT, Jaipur 22