THE UTARAKAHND FLOODS OF JUNE 2013 AND THE KEDARNATH TRAGEDY WHAT COULD HAVE HAPPENED?

Transcription

1 THE UTARAKAHND FLOODS OF JUNE 2013 AND THE KEDARNATH TRAGEDY WHAT COULD HAVE HAPPENED?

2 GEOGRAPHICAL SET UP

3 UTTARAKHAND STATE AREA - 53,484 sq.km FOREST AREA - 34,651 sq.km. (63.93%) HILLY AREA - 46,035 sq.km. (86.07%) PLAINS - 7,449 sq.km. (13.93%) DIVISIONS - KUMAON AND GARHWAL DISTRICTS IN KUMAON AND 7 IN GARHWAL

4 DISTRICTS OF UTTARAKHAND

5 MEAN ANNUAL RAINFALL

6 DRAINAGE OF UTTARAKHAND THE STATE IS DRAINED BY FOUR RIVER SYSTEMS THE KALI/SARDA RIVER SYSTEM THE RAMGANGA RIVER SYSTEM THE YAMUNA RIVER SYSTEM THE GANGA RIVER SYSTEM ALL THESE RIVERS ULTIMATELY JOIN THE RIVER GANGA

7 THE GANGA RIVER BASIN

8 DRAINAGE MAP OF UTTARAKHAND

9 THE KALI RIVER SYSTEM RIVER KALI CALLED SARDA IN THE PLAINS EMERGES AT AN ALTITUTDE OF 3600 m AT KALAPANI FORMS A CONTINUOUS BOUNDARY BETWEEN INDIA AND NEPAL GORI GANGA JOINS IT AT JAULJIBI DHAULI GANGA JOINS AT TAWAGHAT SARYU JOINS AT PANCHESWAR

10 THE RAMGANGA RIVER SYSTEM RIVER RAMGANGA ORIGINATES FROM ELEVATION 3200 m FED BY NAMIK GLACIER JOINS RIVER SARYU AT ELEVATION 456 m NEAR RAMESHWAR GHAT HAS A LOW TO MODERATE GRADIENT OF ABOUT 2% ENTERS THE PLAINS AT KALAGARH WHERE THE RAMGANGA DAM HAS BEEN CONSTRUCTED

11 THE YAMUNA RIVER SYSTEM RIVER YAMUNA ORIGINATES AT YAMUNOTRI GLACIER AT AN ELEVATION OF 6320 m IN THE SW SLOPES OF BANDARPOONCH PEAKS JOINS RIVER TONS WHICH BRINGS ALMOST 65% OF ITS DISCHARGE AT KALSI ENTERS PLAINS AT DAK PATHAR ENTERS HARYANA WHERE THE HATHINI KUND BARRAGE HAS BEEN CONSTRUCTED

12 GANGA RIVER SYSYEM TWO MAIN RIVERS ALAKNANDA AND BHAGIRATHI MEET AT DEVPRAYAG AND THEREAFTER KNOWN AS GANGA ALAKNANDA TRAVELS FOR ABOUT 190km FROM SOURCE TO DEVPRAYAG BHAGIRATHI TRAVELS FOR ABOUT 205km FROM SOURCE TO DEVPRAYAG

13 RIVER ALAKNANDA RISES AT CONFLUENCE AND FOOT OF SATOPANTH AND BHAGIRATH KHARAK GLACIERS MEETS DHAULIGANGA AT VISHNUPRAYAG NANDAKINI AT NANDPRAYAG PINDER AT KARNPRAYAG MANDAKINI AT RUDRAPRAYAG

14 RIVER BHAGIRATHI ORIGINATES FROM GOMUKH IN GANGOTRI GLACIER MEETS JADH GANGA AT BHAIRONGHATI KAKORA GAD AND JALANDHARI GAD NEAR HARSIL SIYAN GAD NEAR JHALA ASSI GANGA AT GANGOORI BHILANGANA NEAR OLD TEHRI

15 RIVER MANDAKINI ORIGINATES FROM THE CHORABARI GLACIER NEAR KEDARNATH KEDARNATH TEMPLE ELEVATION 3590m CHORABARI TAAL A GLACIAL LAKE FORMED AT ALTITUDE OF 3900m ABOUT 250 m LONG, 150 m WIDE AND m DEEP ONLY ABOUT 2 km FROM KEDARNATH

16 DARINAGE SYSTEM JADHGANGA KAKORI GAD JALANDHARI GAD SIYAN GAD ASSI GANGA KEDARNATH MANDAKINI VISHNUPRAYAG DHAULIGANGA NANDAKIN I BHILANGANA NANDPRAYAG BHAGIRATHI DEVPRAYAG RUDRAPRAYAG GANGA ALAKNANDA PINDER KARNPRAYAG

17 WEATHER CONDITIONS IN JUNE 2013

18 RAINFALL DURING JUNE EXTREMELY HEAVY RAINFALL RECORDED DURING JUNE 16, 17 AND 18 DEHRADUN JUNE 16/ mm/370 mm HARIDWAR JUNE 16/ mm/218 mm UTTARKASHI JUNE 16/ mm/207 mm MUKTESHWAR JUNE 17/ mm/183 mm NAINITAL JUNE 17/ mm/ 170 mm

19 RAINFALL DURING JUNE 13 19, 2013

20 WAS THERE A CLOUDBURST? CLOUBURST IS A HIGH INTENSITY RAIN (>100mm/h) OVER A LOCALISED AREA CAUSED BY CUMULONIMBUS CONVECTION CONDITION RAPID LIFTING OF CLOUDS BY STEEP OROGRAPHY OF A REGION THE CLOUDS CAN EXTEND UPTO 15 km ABOVE GROUND FORMATION OF TOWERING DENSE CLOUDS LIFTING CAUSES THERMODYNAMIC INSTABILITY RESULTING IN RAPID CONDENSATION

21 WAS THERE A CLOUDBURST? NONE OF THE IMD SELF RECORDING RAINGAUGES RECORDED CLOUDBURST TYPE OF RAIN (>100mm/h) MAXIMUM ONE HOUR RAIN RECORDED RISHIKESH 43.0 mm JUNE 16 DEHRADUN 40.0 mm JUNE 17 LOHAGHAT 34.0 mm JUNE 18 MUKTESHWAR 26.0 mm JUNE 17 TEHRI 22.0 mm JUNE 16

22 WAS THERE A CLOUDBURST? CLOUD TOP TEMPERATURE IS AN INDICATOR OF MAXIMUM CONVECTION LOWER THE TEMPERATURE, HIGHER THE RAINFALL INTENSITY CLOUD TOP TEMPERATURES DERIVED THROUGH SATELLITE DATA OF JUNE 16 SHOW A LOWEST OF K VERY CLOSE TO DEHRADUN OBSERVATORY NO OTHER PLACE MIGHT HAVE RECORDED A HIGHER RAINFALL INTENSITY THAN DEHRADUN

23 WAS THERE A CLOUDBURST? ALL THE ABOVE INDICATE THAT THERE WAS NO CLOUDBURST THE FLOODS WERE A RESULT OF PROLONGED AND WIDE SPREAD HEAVY TO VERY HEAVY RAINFALL OVER THE ENTIRE REGION

24 WHAT CAUSED THE RAINFALL? RAPID ADVANCE OF MONSOON WHICH COVERED THE ENTIRE NORTH INDIA BY JUNE 15 WESTERLY WINDS FROM ARABIAN SEA AT THE SAME TIME INTERACTION OF THESE APPEARS TO BE THE CAUSE OF SUCH HEAVY RAINS

25 COLLISON OF MONSOON AND WESTERLY DISTURBANCE

26 THE FLOOD SCENARIO

27 THE FLOOD SITUATION DURING THE PERIOD JUNE 15 18, MOST OF THE RIVERS IN THE STATE WERE IN SPATE MOST OF THE SITES ON RIVERS OTHER THAN MANDAKINI AND KALI DID NOT CROSS THEIR PREVOUS HIGH FLOOD LEVEL MANDAKINI AT RUDRAPRAYAG CROSSED THE PREVIOUS RECORDED HFL BY 5.3 m

28 THE FLOOD SITUATION SITES DOWNSTREAM OF RUDRAPRAYAG ON ALAKNANDA/GANGA EITHER CROSSED THE PREVIOUS HFL OR WERE VERY NEAR TO IT THE EFFECT STARTED GETTING MILDER DOWNSTREAM OF RUDRAPRAYAG THE RIVER KALI CROSSED ITS PREVIOUS HFL AT JAULJIBI AND PANCHESHWAR

29 THE FLOOD SITUATION THE MAXIMUM DISCHARGE AT BHIMGODA HEADWORKS, HARIDWAR WAS 5.25 lac cusecs (15000 cumecs) AT 19:00 hrs. ON JUNE 17 MAXIMUM INFLOW INTO TEHRI RESERVOIR AT 04:00 hrs ON JUNE 17 WAS 2.65 lac cusecs (7500 cumecs) WHILE THE OUTFLOW WAS 0.13 lac cusecs (368 cumecs) THUS 2.52 lac cusecs (7124 cumecs) WAS ABSORBED BY TEHRI RESERVOIR, WHICH WOULD HAVE OTHERWISE RAISED THE FLOOD AT BHIMGODA TO ABOUT 6.5 lac cusecs (18400 cumecs)

30 THE FLOOD SITUATION ALMOST ALL RIVERS IN NORTH INDIA EXPERIENCED HEAVY FLOODS YAMUNA RECORDED A FLOOD OF 8.06 LAC CUSECS (21,211.8 CUMECS) AT THE HATHINI KUND BARRAGE IN HARYANA ON THE MORNING OF JUNE 17, THE DISCHARGE RECORDED AT JOSHIYARA BARRAGE ON THE RIVER BHAGIRATHI WAS 74,590 CUSECS ( CUMECS).

31 THE FLOOD SITUATION THE PEAK DISCHARGE RECORDED AT THE SARDA BARRAGE ON RIVER KALI BETWEEN JUNE 17 AND 18 WAS 5,50,000 CUSECS (15,710 CUMECS) AS AGAINST A 100 YEAR DESIGN FLOOD OF 5,25,000 CUSECS (15,000 CUMECS)

32 THE KEDARNATH TRAGEDY

33 KEDARNATH TEMPLE AND THE GLACIER

34 THE KEDARNATH AREA

35 THE KEDARNATH AREA

36 THE KEDARNATH AREA

37 WHAT COULD HAVE HAPPENED? THE INTENSE RAINFALL CAUSED A MASSIVE LANDSLIDE ABOUT 75 m WIDE IN THE UPPER REACH TOWARDS NORTH EAST THE MELTING RATE OF GLACIERS WAS HIGH BECAUSE OF THE HIGHER TEMPERATURES IN MID JUNE THERE HAD BEEN FRESH SNOWFALL AND THE RAIN MELTED THIS SNOW ALSO CAUSING A LARGE RUNOFF

38 WHAT COULD HAVE HAPPENED? INFLOW TO THE CHORABARI LAKE WAS MORE THAN THE OUTFLOW - LEFT EMBANKMENT OVERTOPPED POSSIBILITY OF A SNOW AVALANCHE TRIGGERED FROM THE WESTERN SIDE OF THE LAKE THE WAVES RUPTURED THE LEFT EMBANKMENT ABOUT 10 5 m 3 OF WATER WAS RELEASED IN LESS THAN 10 minutes (GLOF)

39 WHAT COULD HAVE HAPPENED? THE FLOW APPROACHED KEDARNATH IN TWO CHANNELS DEBRIS LADEN FLOW FROM NORTH EAST AND GLACIAL FLOW FROM NORTH WEST THE FLOW ALSO ENTRAINED DEBRIS EN ROUTE AND THUS A MUD AND WATER WALL HIT KEDARNATH FLATTENING ALMOST EVERYTHING

40 PRE AND POST FLOOD IMAGES

41 WHAT COULD HAVE HAPPENED? IT CAN BE CONCLUDED THAT THE EXTREME FLOOD SITUATION WAS DUE TO A COMBINATION OF FACTORS SUCH AS UNPRECEDENTED EARLY RAINFALL LANDSLIDES LEADING TO DEBRIS LADEN FLOW HIGH MELTING RATE OF GLACIERS BECAUSE OF HIGHER TEMPERATURES IN MID JUNE FRESH SNOWFALL WHICH MELTS EASILY BREACHING OF GLACIAL LAKE

42 DAMAGE IN OTHER RIVER VALLEYS

43 THE KALI RIVER VALLEY THE LOSS OF HUMAN LIFE WAS MUCH LESS TIMELY EVACUATION OF PEOPLE LOSS TO LIVESTOCK AND PROPERTY CONSIDERABLE REPORTED AFFECT ON 32 VILLAGES 7 BRIDGES 6 HYDROPOWER PLANTS INCLUDING ONE MAJOR

44 OTHER EFFECTS LARGE NUMBER OF LANDSLIDES ALL OVER THE AREA DISRUPTION OF COMMUNICATION ROADS BLOCKED IN A LARGE PART OF THE STATE

45 LANDSLIDES GEOLOGICAL SURVEY OF INDIA CARRIED OUT SURVEY IN FIVE DISTRICTS OF THE STATE INTERIM SURVEY INDICATED 330 EROSION INCIDENCES INCLUDING NEW SLIDES AS WELL AS OLD ONES REACTIVATED

46 LANDSLIDES DISTRICTWISE BREAK UP BAGESHWAR 100 CHAMOLI 65 PITHORAGARH 63 RUDRAPRAYAG 54 UTTARKASHI 48

47 SOME COMMENTS

48 OTHER FACTORS THE RIVERS WERE CARRYING A LOT OF SEDIMENT PRIMARILY BECAUSE OF LARGE SCALE DEFORESTATION AND INADEQUATE SLOPE STABILISATION AND MUCK DISPOSAL DURING ROAD CONSTRUCTION LARGE SCALE LOSS OF PROPERTY WAS A RESULT OF ENCROACHMENT OF FLOOD PLAINS OF RIVERS FOR COMMERCIAL PURPOSES

49 WHAT CAN BE DONE? INSTALLATION OF EARLY FLASH FLOOD WARNING SYSTEMS IDENTIFICATION OF LANDSLIDE PRONE AREAS AND REACHES VULNURABLE TO BANK FAILURE AND TAKE ADEQUATE PROTECTION MEASURES MONITORING OF GLACIAL LAKE FORMATION AND WHEREVER POSSIBLE REMOVE SUCH BLOCKAGES IN A SAFE MANNER

50 WHAT CAN BE DONE? SOIL CONSERVATION MEASURES LIKE AFFORESTATION OF HILL SLOPES SELECTIVE REMOVAL OF DEBRIS FROM RIVER BED CONSTRUCTION OF STORAGES WHEREVER FEASIBLE FOR FLOOD MODERATION REGULATION OF COMMERCIAL ACTIVITY IN FLOOD PLAIN OF THE RIVERS PROPER CARE IN MUCK DISPOSAL FROM ROAD AND OTHER CONSTRUCTION ACTIVITIES

51 THANK YOU