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IUKWC Workshop Nov16: Developing Hydro-climatic Services for Water Security – Session 4 – Item 1 Das

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IUKWC Workshop November 2016: Developing Hydro-climatic Services for Water Security
Session 4.1 Ashok Kumar Des

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IUKWC Workshop Nov16: Developing Hydro-climatic Services for Water Security – Session 4 – Item 1 Das

  1. 1. Operational Hydro-meteorological Services Dr. Ashok Kumar Das
  2. 2. HYDROMETEOROLOGY DIVISION New Delhi LAND MARKS  1890- Govt. of India passed the Rainfall Resolution of India which made India Meteorological Department as controlling authority for all rainfall measuring agencies.  1949 - A special hydrometeorological unit was established at Alipore, Kolkata to provide operational met service to Damoder Valley Corporation.  1963 – Storm Analysis Unit was established as per Khosala Committee’ s recommendations  1971 - The Hydromet Division is formally established to cater increasing demands of value added information to rainfall data as per users’ specific needs.
  3. 3. HYDROMET SERVICES Hydromet Activities Hydro met Design Rainfall Monitoring Hydro met Forecasting (QPF) for Flood Forecasting
  4. 4. HYDROMET DESIGN
  5. 5. RAINFALL IN INDIA  RAINFALL : 118.62 cm ( ANNUAL), 88.70 cm (SW Monsoon) 4.09 cm (Winter) 13.12 cm (Pre-Monsoon) 12.71 cm (Post-Monsoon) (Data 1951-2000 used for Normal RF)  HIGHLY VARIABLE IN SPACE 15% AREA OF INDIA > 150 CMS 64 % AREA OF INDIA 75 – 150 CMS 15% AREA OF INDIA 40 – 75 CMS 6% AREA OF INDIA < 40 CMS  HIGHLY VARIABLE IN TIME 75 % OF ANNUAL RAINFALL OCCURES DURING 4 MONTHS.  HENCE STORAGE STRUCTURES ARE NEEDED TO MANAGE BALANCE 8 MONTHS.
  6. 6. Hence we have to develop infra structure for full exploration of available potential. Water Availability in India Area of the country 32,87,263 Km2 Total utilizable water resources 1123 BCM Surface water potential 690 BCM per year Ground water potential 433 BCM Expected water demand 1050 BCM (by YEAR 2025 )
  7. 7.  At the end of 2011, there are more than 4845 large* dams, and 347 under construction to meet the demand of power generation and Flood Control.  The total storage capacity of these dams, is about 283 billion M3.  Because of the huge investment, safety of these structures, Requirement of Water Supply, Hydro-electrical power need to be insured.  The main cause of dam failures is over toppling by excess inflow.  Hence, spillway should have adequate out flow capacity for Dam safety (* height ≥ 15 M or storage Capacity > 1 Million M3) (Source: National Register of large dams, compiled by CWC, MoWR up to Feb. 2012) Requirement of Dam safety
  8. 8. FEW EXAMPLES OF DAM FAILURE DUE TO INADEQUATE SPILLWAY CAPACITY KADDAM DAM 1958 PANSHET & KHADAKWASLA DAM 1961 MACHHU PROJECT – II 1979 KOSI BARRAGE 2008 DAM FAILURE
  9. 9. Design Floods are estimated from Design storm studies. In order to cater this need, Hydromet Division of IMD undertakes the Design Storm studies comprising of “Estimation of Probable Maximum Precipitation (PMP)” with the help of isohyetal analysis of rainfall DESIGN STORM STUDIES
  10. 10. The Probable Maximum Precipitation is obtained from - Isohyetal Analysis of historic rain storms. - Transposition of artificially selected rainstorm to the project basin. - Further maximizing the rainstorm to extreme moisture condition etc. to arrive at PMP DESIGN STORM STUDIES
  11. 11. In case of minor structures like bridges, culverts, planning of water supply system & drainage systems, railway and road bridge construction etc., IMD provides  Estimates of short duration rainfall return period values  Isopluvial maps  Intensity Duration Frequency (IDF) curve For Govt. agencies, these studies are being carried out free of cost and for private / profit earning agencies on payment basis. DESIGN STORM STUDIES
  12. 12. RAINFALL MONITORING
  13. 13. Information Disseminated to USERS Prime Minister House Cabinet Secretary Agriculture Ministry State Agencies Finance Ministry Foreign Embassies Insurance Companies CWC, NCMRWF & NRSA Rain Recording Station Station R/F transmitted to R.M.C. / M. C. Regional / Met. Centre Districtwise R/F statistics is prepared Districtwise R/F is transmitted to Hydromet Division, New Delhi. HYDROMET Prepares R/F statistics for the Subdivisions, States, Regions and the Country DATA PROCESSING FOR RAINFALL SUMMARY REPORTS  In 1989 the Districtwise Rainfall Monitoring Scheme (DRMS) got approved for compiling rainfall summary for all the seasons and for Districts / met sub Divisions and Country as whole. IMD are compiling District / met sub divisional and Country’s realtime rainfall summary for appraisal of Rainfall situation on daily/ weekly/ monthly/ seasonal/ annual basis.  About 3500 stations data are being used for preparation of real time rainfall summary. The rainfall summary is thus updated on monthly basis after incorporating late data at RMC /MC level.
  14. 14. Scheme of computations.  The estimate of District rainfall is made by Arithmetic Mean Method RDist = ∑ Ri / N  It was then thought of estimating sub divisional average rainfall from Arithmetic Method considering all the stations’ rainfall in the sub Division in same way like district rainfall. But it was noticed that there is bias towards the area where density of rain gauges is higher than other parts.  Hence met sub Divisional rainfall estimates are made taking Area Weighted Average Rainfall of Districts of that met sub Division RsD = ∑ RDist*ADist / AsD  The rainfall summary for country as whole is compiled as area weighted average rainfall of met sub Divisions in similar way. Rcountry = ∑ RsD*AsD / Acountry
  15. 15.  For given week (period), the summary for dist., Met. Sub Division and Country comprises of - Actual Rainfall Estimate - Normal Rainfall for given period (based on 1951 -2000 rainfall data) - Departure from Normal = (Actual R/F – Normal R/F) / Normal R/F (expressed in terms of %) - Category Excess – When Departure > 19% Normal -19% ≤ Departure ≤ 19% Deficient -59% ≤ Departure < -19% Scanty -99% ≤ Departure < -59% No Rain Departure = -100% Scheme of computations.
  16. 16. Sub Division wise and State wise Maps
  17. 17. DISTRICTWISE RAINFALL MAP
  18. 18. DISTRICTWISE RAINFALL MAP
  19. 19. DISTRICTWISE RAINFALL MAP
  20. 20. DISTRICTWISE RAINFALL DISTRIBUTION
  21. 21. CRIS (CUSTOMISED RAINFALL INFORMATION SYSTEM) THE SYSTEM CRIS WHICH WAS MADE OPERATIONAL ON 15TH JANUARY, 2015 ON IMD WEBSITE PROVIDES REAL-TIME RAINFALL INFORMATION BY MEANS OF GIS BASED RAINFALL PRODUCTS FOR ANY PLACE IN INDIA. Rainfall Maps Rainfall Graphs Rainfall Statistics Rainfall Departures Spatial Analysis CRIS PRODUCTS
  22. 22. Computation of River basin wise rainfall statistics(actual, normal & % dep.) which is useful for flood forecasting and Water Resources management New Products on CRIS (River Basin wise information) RIVER BASIN-WISE SPATIAL ANALYSIS OF OBSERVED RAINFALL IS USEFUL FOR FLOOD FORECASTING AND WATER RESOURCE MANAGEMENT
  23. 23. Real time Hourly cumulative (one day) AWS/ARG rainfall data on Pan India. Useful for real time rainfall information, Urban flooding etc. REAL TIME STATIONWISE RAINFALL DATA ON CRIS
  24. 24. Products on CRIS Cumulative Rainfall distribution. Useful for real time rainfall information State-wise Rainfall map District wise rainfall map for a State (Available for all states) THE DISTRICT-WISE RAINFALL STATISTICS IS HELPFUL TO FARMERS FOR THEIR AGRICULTURAL ACTIVITIES.
  25. 25. Products on CRIS WEEK-BY-WEEK DEPARTURES OF RAINFALL FROM NORMAL HELP VARIOUS STAKE HOLDERS (LIKE GOVT. AGENCIES, FLOOD AND DROUGHT MITIGATING AGENCIES, INSURANCE AGENCIES ETC.) FOR ESTIMATING DROUGHT AND FLOOD CONDITIONS IN THE COUNTRY. SEASONAL & ANNUAL NORMAL RAINFALL (1951- 2000 ) MAPS OF STATE, MET SUB DIVISION AND RIVER BASINS
  26. 26. CUSTOMIZED RAINFALL INFORMATION SYSTEM (CRIS)
  27. 27. Hydro met Forecasting (QPF) for Flood Forecasting
  28. 28. NATURE OF FLOODS IN INDIA Maximum floods Occur in S-W MONSOON season. Flood is an ANNUAL FEATURE of major rivers. According to the estimate of the National Commission on Flood, the area prone to floods in the country was of the order of 40 million hectares, out of which it is considered that 80%, i.e., 32 million hectares could be provided with reasonable degree of protection. On an average75000 SQ. KMS of area & 33 million population faces FLOOD WRATH every year.
  29. 29. ......... . . . . PAKISTAN 88o 72o 76o 80o 84o 88o 92o 96o 36o 32o 28o 24o 20o 16o 12o 8o 92o88o84o80o76o72o 8o 12o0 16o0 20o 24o 28o 32o 36o HIMACHAL PRADESH UTTAR PRADESH HARYANA RAJASTHAN GUJRAT MADHYA PRADESH MAHARASHTRA BIHAR ORISSA TRIPURA MIZORAM MANIPUR NAGALANDASSAM CHINA TIBET BHUTAN Narmada Saraswati Mahi ANDHRA PRADESH TAMIL NADU KARNATAKA KERALALAKSHA DWEEP (INDIA) INDIAN SRI LANKA OCEAN MYANMAR Tasango BAY OF BENGAL ANDAMAN AND NICOBAR ISLANDS (INDIA) GOA ARABIAN SEA SRINAGAR NEW DELHI JAIPUR GANDHINAGAR BHOPAL MUMBAI HYDERABAD PANAJI CHENNAIBANGALORE KAVARATI THIRUVANANTHAPURAM PORTBLAIR BHUBANESHWAR AIZAWALAGARTALA IMPHAL KOHIMA SHILLONG DISPUR ITANAGAR GANGTOK MEGHALAYA KOLKATA ARUNACHAL PRADESH SIKKIM BANGLADESH FLOOD PRONE AREA Kilometres100 50 0 100 200 300 400 Kilometres Miles100 50 0 100 200 300 Miles SCALE JAMMU & KASHMIR SHIMLA CHANDIGARH WEST BENGAL PATNA NEPAL LUCKNOW PUNJA B Flood Prone areas in India ~ 40 million Ha (RBA,1980)  Major Flood Prone States: Assam, Bihar,West Bengal, UP,  Odisha & Andhra Pradesh  Major Flood Prone Basins: Ganga, Brahmaputra & Mahanadi
  30. 30. In past 50 years India had lost assets of more than RS 650000 million (@ US$ 14800 million) and loss of more than 75000 human lives due to floods alone. FLOOD DAMAGES
  31. 31. EXPERTS OPINION Though total immunity from floods is not feasible, the losses particularly of lives and movable property can be minimized by  Structural Measures  Non Structural Measures Structural Non Structural Construction of Dams, Embankments etc Flood Warnings Flood plain zoning etc Costly Relatively less costly Saves both movable and immovable property Saves only movable property.
  32. 32. CAUSES OF FLOOD  HEAVY RAINS IN SHORT PERIOD  LANDSLIDES AND AVALANCHES  CHANGE IN RIVER COURSE  FAILURE OF DAMS AND OTHER HYDRAULIC STRUCTURES  ENCROACHMENT IN FLOOD PLAIN AREAS  CYCLONES,THUNDERSTORMS, CLOUD BURSTS  GLACIAL OUT BURST However majority of floods occur due to Heavy rains in short period. Hence accurate QPF is a prime factor of reasonable Flood forecasting and warning.
  33. 33. BREACH IN KOSI BARRAGE IN AUGUST 2008 CAUSES OF FLOOD
  34. 34. Flood Forecasting MINISTERIAL COMMITTEE ON FLOODS &FLOOD RELIEF-1972 RECOMMENDED THAT  Flood Forecasting Centres should be established in all flood prone basins.  Flood Meteorological Offices should be established by India Meteorological Department to work in close co-operation with Flood Forecasting Centres FLOOD METEOROLOGICAL OFFICE (FMO) INDIA METEOROLOGICAL DEPARTMENT COORDINATION CENTARL FLOOD FORECASTING DIVISION (CFFD) CENTRAL WATER COMMISSION QUANTITATIVE PRECIPITATION FORECAST FLOOD FORECAST FLOOD FORECASTINGIn India Flood Forecasting activity is the joint responsibility of India Meteorological Department  Central Water Commission. IMD provides Hydromet Input through their Flood Forecasting Offices(FMOs). In hydromet input, Quantitative Precipitation Forecast (QPF) is the main input which is used in rainfall runoff models by CWC.
  35. 35. Sl. No. FMOs Date of Estt. River Basins 1 Agra 29-Mar-1985 Banganga, Chambal, Betwa, Ken, Yamuna 2 Ahmedabad Jan-1974 Narmada, Tapi, Daman-Ganga, Sabarmati, Banas, Mahi 3 Asansol Mar-1980 Ajoy, Mayurakshi, Kangsabati 4 Bhubaneswar 11-Jan-1974 Subarnarekha, Baitarni, Burhabalang, Vamsadhara, Brahmani, Mahanadi, Rushikulya 5 Guwahati Aug-1975 Brahmaputra, Barak, Dehung, Lohit, Buridihing, Subansiri, Dhansiri (N,S), Jiabharali, Kapili, Manas/ Beki, Sankosh 6 Hyderabad Apr-1977 Godavari, Krishna 7 Jalpaiguri 24-Jul-1974 Teesta, Jaldhaka, Raidak 8 Lucknow Sep-1974 Ghaghra, Rapti, Ramganga, Gomti, Sai, Sahibi, Chhatang, Bhagirathi, Alaknanda, Ganga 9 New Delhi 15-Jun-1974 Yamuna, Sahibi 10 Patna Dec-1973 Kosi, Mahananda, Adhwara, Bagmati, Gandak, Punpun, Sone, Kanhar, North Koel 11 MC Srinagar Jun-2015 Jhelum, Dah, Nimmo, Khalsi 12 RMC Chennai Jun-2016 Pennar, Lower Cauvery, Vaigai, Vellar 13 MC Bengaluru Jun-2016 Krishna, Cauvery, Tungabhadra 14 DVC 1949 Barakar, Damodar, Lower Valley
  36. 36. SYNOPTIC ANALYSIS SATELLITE PRODUCTS RADAR PRODUCTS ANALYSIS QPF Inputs for issuing of QPF SYNOPTIC ANALOGUE NWP MODEL
  37. 37. DURING FLOOD SEASON, FMOs send QPF Bulletin (9.30AM) and HYDROMET BULLETINS (12.30PM) to CFFD which includes following :  CATEGORICAL SUB BASIN WISE QUANTITATIVE PRECIPITATION FORECAST (QPF) FOR THE NEXT THREE DAYS AND OUTLOOK FOR FURTHER FOUR DAYS FOR THE CONCERNED CATCHMENTS/SUB-CATCHMENTS  PREVAILING SYNOPTIC SITUATIONS  SUB BASIN WISE AREAL RAINFALL OCCURRED DURING PAST 24-HOURS  STATIONWISE SIGNIFICANT RAINFALL DURING THE PAST 24-HOURS  HEAVY RAINFALL WARNING FOR THE NEXT 72-HOURS HYDROMET BULLETIN Other than flood season, QPF is to be issued to CFFD under following eventualities: During the period of ‘Flood Alert’ for specified basins as notified by CFFDs. If heavy rainfall is expected during non-flood season or in the event of formation of Cyclone, concerned FMO will issue QPF/HM Bulletins.
  38. 38. FMOs ALSO PERFORM FOLLOWING FUNCTIONS DURING NON FLOOD SEASON :  PREPARATION OF SYNOPTIC ANALOGUE MODEL FOR QPF  PREPARATION OF HYDROMETEOROLOGY OF RIVER BASINS  FMO STATIONS ARE BEING INSPECTED BY THE RESPECTIVE FMOs EVERY YEAR FOR ACCURATE AND EFFICIENT RECEPTION OF RAINFALL DATA ON REAL TIME BASIS FLOOD METEOROLOGICAL OFFICES
  39. 39. Flood Forecasting: Basic Structure . Hydrological ModelHydrological Observations Reception of Rainfall data from RCs/MCs/FMOs Weather Forecasts(QPF) SYNOPTIC CHART, SATELLITE& RADAR PRODUCTS, SYNOPTIC ANALOGUE & Weather Forecast Models FMO CFFD Flood Warnings
  40. 40. OUTPUT PRODUCTS OF WRF OUTPUT PRODUCTS OF MME OUTPUT PRODUCTS OF GFS Following sub basin wise model rainfall forecast products are uploaded in the IMD website; WRF(ARW) (9km x 9km) (00utc & 12 utc), Multi-Model Ensemble (27km x 27km) (00utc) GFS (22kmx22km) (00utc) SUB BASIN WISE OPERATIONAL WRF, MME AND GFS
  41. 41. QUANTITATIVE PRECIPITATION FORECAST The performance of operational QPF and dynamical NWP model forecast are verified during the monsoon season by computing different skill score tests viz. Percentage Correct Forecast(PC), Heidke Skill Score (HSS) and Critical Success Index (CSI) from 6X6 Contingency table.
  42. 42. QUANTITATIVE PRECIPITATION FORECAST  The POD, FAR, MR, C-NON, CSI, BIAS, PC, TSS and HSS for each category are computed by reducing the 6X6 contingency table into 2X2 contingency table for occurrence / non occurrence (YES/NO).  The computing procedure for various skill scores tests are as follows over sub basins.
  43. 43. DROUGHT MONITORING On the recommendations of the Planning commission, Drought Research Unit started functioning at Pune in 1967 in the office of the Additional Director General of Meteorology (Research). The salient activities of this Unit are as under:- i. Defining meteorological Drought and its intensity. ii. Delineation and identification of Drought Prone areas of the country iii. Study of past droughts and iv. Monitoring Agricultural drought conditions during Southwest and Northeast monsoons v. Issuing weekly aridity outlook and vi. Research on different aspects of drought.

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