Glacial Lake Outburst Flood (GLOF) hazards in the Upper Indus basin International Conference on Climate and environment change impacts on the Indus basin waters 16-19 February 2016 Samjwal Ratna Bajracharya, Sudan Bikash Maharjan and Finu Shrestha International Centre for Integrated Mountain Development ICIMOD Kathmandu, Nepal
Contents Past glacial lake outburst floods in Indus basin Status and change of glaciers in Indus basin Status and change of glacial lakes in Indus basin Potentially dangerous glacial lakes in Indus basin Conclusions
GLOF events in Himalaya 57 GLOF events have been reported from the Himalayas. Tibet Autonomous Region, China 30, 10 GLOF events trans-boundary to Nepal 9 GLOF events trans-boundary to Bhutan Nepal - 14 GLOF events Bhutan - 13 GLOF (including Lemthang Tso GLOF in 28 June 2015)
Some devastating GLOF events in UIB A total of 57 destructive outburst floods have been recorded in the Upper Indus Basin (UIB) including at least 11 surges are of exceptional scale. Thirteen GLOFs recorded from 2001 to date Forty-four GLOFs recorded from 1826 to 2000
Destructive outburst floods in Upper Indus basin SN Year River System Glacier/Glacial Lake Damage description 45 2001 Chitral 46 2005 Chitral At Yarkun Last village, situated at about 9000ft, GLOF killed a large number of livestock, damaged many houses, agricultural land with crops and fruit & forest trees, when a big block of glacier fell onto the lake. In the same year another GLOF even occurred in Wasum village Yarkhun, but there was no damage to the habitation. In Brep village, GLOF damaged the main irrigation channel, hydropower, demolished 32 houses, and killed a large number of livestock. 47 2007 Chitral In Snogar village, GLOF damaged agricultural land with crops, killed a large number of livestock and damaged many houses. 48 11-May-08 Hunza Gulkani and Passu, 49 21-May-08 Hunza Gulkani and Passu, Damaging properties and infrastructure 50 25-May-08 Hunza Gulkani and Passu Potao and wheat crops 51 31-May-08 Hunza Gulkani and Passu Crop fields and trees 52 14-Jun-08 Hunza Gulkani and Passu Infrastructure and properties 53 2009 Chitral Nine people were killed and 13 household displaced in Snogar village 54 2010 Booni Booni about 200 acres of private land and 4 bridges, water channels Govt School, Aga Khan School and Forest Office were damage 55 2010 Bindo Gol Glacier Bindo Gol Glacier Two human lives, damage to 10 houses, 13 water channels many fruit and forest trees and 5 bridges 56 Jul-13 Booni Booni 28 houses, almost all irrigation channels and crops were damaged. Many springs have dried out, a 500 ft deep ditch has formed due to landslide and about half a km slopping land near glacier is likely to slip down because of bank erosion. 57 2013 Chitral In Roi village many houses were damaged
SN Year Glacier/River System Glacial lake Description 1 1826 Upper Shyok river Khumdan Major flood wave, Serious flooding 2 1833a Upper Shyok river Khumdan Not serious 3 1833b? Yashkuk Yaz Glacier Yashkuk Yaz Gl on Chapursan Trib. of Hunza River, devastating flood 4 1835 Sultan Chhussku Glacier Chong Khumdan GL No noticeable rise 5 1839 Kumdang Much less extent than 1835 6 1842 Upper Shyok river Khumdan Small flood 7 1844 Ishkoman river serious floods in Gilgit area 8 1848 Khumdan 9 1850b? Chungphar Glacier, Astor valley Tarshing GL local devastation 10 1855a Upper Shyok ri ver Gol village innundated 11 1855b Upper Shyok river Khumdan? Major flood wave, originally large rise at Attock 12 1865 Ishkoman ri ver Ice dam brust bringing serious flooding in Gilgit 13 1879? Upper Shyok river Khumdan Major flood wave 14 1882 Upper Shyok river Khumdan Major flood wave 15 1884 Shimshall river Ice dam brurst considerable devastation at Ganesh and Altit in Hunza valley 16 1893a Shimshall river Glacial dam burst Shimshall valley 17 1893b Ishkoman ri ver flood reached Gilgit on 6th July, 23 ft above summer flood level 18 1901? Upper Shyok river (?) Khumdan dam burst Rise 20 ft 19 1903 Kichik Khumdan Glacier Kichik, Khumdan Serious damage 20 1905a Kichik Khumdan Glacier Khumdan Small flood 21 1905b Karambar Glacier Karambar Minor flood wave: Considerable damage at Gilgit area 22 1905c Khurdopin Glacier Khurdopin-Virjerab dam Shimshall valley; flood in Hunza valley; fllod wave 30 ft 23 1906 Khurdopin Glacier Khurdopin-Virjerab dam Shimshall valley; Askurdas, Tushot and Chamogah bridges washed awy 50 ft above highsummer flood in Hunza gorge 24 1907 Khurdopin Glacier Khurdopin-Virjerab dam Maximum rise at Bunji only 7 ft 25 1919/20 Bindo Gol Glacier GLOF continued for 3 years and many people migrated from their homes 26 1926b Chong Khumdan Glacier Chong Khumdan dam burst Minor flood damage at Attock; devastating flood 27 1927a Kaz Yaz Glacier, U Hunza Besk-i-Yeng GL Serious floods of local extent. Massive sediment movement 28 1927b Khurdopin Glacier Khurdopin dam burst 29 1928 Kilik river (U Hunza) Glacial dam burst local damage only 30 15-Aug-29 Chong Khumdan Glacier, Upper Shyok River Chong Khumdan Estimated volume released was about 13.5 106 m3 and peak discharge of 22,650 m3/s, which is considered as the largest discharges measured for the entire Upper Indus and at Attock 1,300 Km downstream with discharge greater than 15,000 m3/s. 31 1932 Chong Khumdan Glacier Chong Khumdam Smaller than 1929, considerable erosion 32 27-Aug-33 Chong Khumdan Glacier Chong Khumdan 33 1950 The death toll recorded was 2,900 34 1959 Shimshal valley 35 1971 Bindo Gol Glacier GLOF washed away 5 houses, 10 flourmills, 12 water channels, and 10 bridges 36 1973/74 Batura Removed a section of the Karakoram Highway embankment and destroyed a major bridge. 37 1977 Pasu Balt Bare Several houses were took away and one important bridge and a long stretch of roadway was buried. 38 0/8/1978 80 houses and a school were washed away., Lake that cause Darkot and Barandos hazard, 39 1979 Kyagar Glacier 40 1996 Bindo Gol Glacier Damaged 3 houses, 13 water channels, 3 human lives including a boy and girl 41 25/7/1997 Hushe River tributary of Shyok River Kande upstream Lake that cause Kande hazard The debris- flow crossed the Gupis to Shandur Road and blocked the Ghizer River, creating a lake about 1.5 km in 6/8/1999 Charti Glacier at Ghizer river Khalti length, now known as Khankhui Lake. The duration of blockage is not known, but the flow over the debris lobe is still
Catastrophic GLOFs 1929 GLOF: GLOF devastation during the period of 1925-33, out of which 1929 GLOF of Chong Kumdan Glacier in upper Shyok River was well monitored and recorded for over 1300 km downstream (Gunn, 1930, Mason et.al.1932). The estimated reservoir to have 1.1 million acre feet (x1233m 3 ) water drained in 48 hours indicating the water discharge of 800,000 cfs. 2008: Five GLOF events were reported during the first half of 2008 in the Gojal area of the Hunza valley and substantial damage to infrastructure and arable land was reported due to GLOF events in association with the Ghulkin and Passu glaciers. 2013: GLOF Disasters in Booni, Upper Chitral : In July 2013, 28 houses, almost all irrigation channels and crops were damaged. Moreover, many springs have dried out, a 500 ft deep ditch has formed due to landslide and about half a km slopping land near glacier is likely to slip down because of bank erosion. In past forests were sustainably managed by communities through the Gram System and rotation grazing (Sak) and control grazing (Sosari)
Impact of climate change Climate change, increased frequency and magnitude of associated extreme weather events, and shifts in monsoon patterns, especially at higher altitudes are playing a role in rapid glacier change, These changes impact the water availability and increased GLOF hazards It is critical to improve our understanding of the changes taking place in the Cryosphere
Status of Glaciers in the HKH basins Glacier Area in HKH: about 60,000Km 2 Glacier Cover in HKH: 1.43% Basins Number Area (km2) Amu Darya 3,277 2,566 Indus 18,495 21,193 Ganga 7,963 9,012 Brahmaputra 11,497 14,020 Irrawaddy 133 35 Salween 2,113 1,352 Mekong 482 235 Yangtze 1,661 1,660 Yellow 189 137 Tarim 1,091 2,310 Interior 7,351 7,535 Total 54,252 60,054 Bajracharya et al. 2011
35.5 0.1 2,566.2 4.3 1,351.8 2.3 234.6 0.4 1,659.9 2.8 137.4 0.2 2,310.3 3.8 Glacier area (km2) 9,011.5 15.0 7,534.6 12.5 23.3 Percentage (%) 14,019.8 35.3 21,192.7 Glacier Area percentage in HKH 25,000 20,000 Glacier area Glacier area percent 50 40 15,000 30 10,000 20 5,000 10 0 0
Elevation (masl) Area-Elevation (Hypsograph) 9,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000 Indus Ganga Brahmaputra 0 200 400 600 800 1000 1200 1400 1600 Glacier area (km 2 )
Debris Cover (DC) Area From the analysis of 32,000 km 2 glacier area (28,500 glaciers) Debris Cover in: Ganges - 12.6% Brahmaputra - 11.06% Indus - 9.3% HKH region - 9.7%
Glaciers in Indus basin Basins Glacier number Glacier area (sq km) Ice reserves (cu km) Kabul 1,601 1,722 183 U. Indus 11,413 15,062 2,174 Panjnad 5,481 4,409 340 Indus 18,495 21,193 2,697
Panjnad Upper Indus Kabul Summary of Glaciers in Indus basin SN Basin Sub Basin 1 Basin Area Highest Elev. Lowest Elev. Glacier area Ice reserves Glacier number (Km 2 ) (m) (m) (sq km) (cu km) Panjsh.-Ghorb 29823 88 5242 3857 14.63 0.442 2 AAN 6217 37 5284 4162 5.82 0.16 3 Kunar 25925 1149 7578 3114 1574 176.8 4 Swat 14728 327 5580 3772 127.4 5.296 Total 94290 1601 7578 3114 1722 182.7 5 Gilgit 13540 968 7730 2703 938.3 71.32 6 Hunza 13734 1384 7749 2409 2754 310.6 7 Shigar 7046 439 8566 2774 2374 601.9 8 Shyok* 33429 3357 7803 3231 5938 981.7 9 Zanskar 15856 1197 6368 3997 975.5 82.13 10 Shingo 10502 882 7027 3656 612.7 42.88 11 Astor 3988 372 8032 2991 239.6 16.88 12 Upper Indus* 75117 2814 7820 2760 1230 66.06 Total 173213 11413 8566 2409 15062 2174 13 Jhelum 50844 733 6285 3404 222.8 8.974 14 Chenab 44840 2039 7103 3001 2341 210.7 15 Ravi 30590 217 5824 3276 113.6 5.508 16 Beas 19500 384 6196 3079 416.6 31.78 17 Sutlej* 1E+05 2108 6652 3606 1315 82.89 Total 286383 5481 7103 3001 4409 339.9
Glacier area loss from 1980 to 2010 (in 30 years) Nepal - 24% Bhutan - 23% Bajracharya et al., 2014 ICIMOD Bajracharya et al., 2014 AoG
Status of Glaciers in Jhelum Basin in 1980, 1990, 2000 and 2010 Area Loss (%) 1980-1990 7.6 1990-2000 11.0 2000-2010 4.4 Year Glacier Number Highest Lowest Glacier Ice Elevation Elevation Diff Elv. Area Reserve (m) (m) (sq.km.) (cu.km.) 1980 817 6285 3520 2765 268.57 10.96 1990 823 6285 3520 2765 248.15 10.04 2000 845 6285 3520 2765 220.83 8.82 2010 846 6285 3527 2758 211.16 8.36 1980 to 2010 (in 30 years) Glacier number increased by 3.5% Glacier area decreased by 21.4%
Comparison of glacial lakes of 2005 and 2015 Upper Indus Basin 2005 Inventory 2015 Inventory Comparison of lakes Number Area (km 2 ) Number Area (km 2 ) Number Area_2005 (km 2 ) Area_2015 (km 2 ) Change Percent Per GL area change (km 2 ) Swat 256 15.401 270 16.445 210 14.444 15.068 4.32 0.003 Chitral 190 10.295 301 9.467 100 6.096 7.406 21.49 0.0131 Gilgit 603 36.293 698 38.464 501 31.664 35.377 11.73 0.0074 Hunza 81 2.640 141 2.974 20 1.229 1.297 5.53 0.0034 Shigar 54 1.038 105 2.332 18 0.401 0.837 108.73 0.0242 Shyok 66 2.539 233 6.774 35 1.835 2.761 50.46 0.0265 Shingo 241 10.955 264 13.413 188 10.215 12.053 17.99 0.0098 Astor 128 5.301 124 5.408 83 4.173 4.235 1.49 0.0007 Jhelum 200 11.393 252 12.912 178 10.894 11.854 8.81 0.0054 Indus 559 24.400 818 35.284 512 23.625 29.011 22.80 0.0105 Total 2378 120.26 3206.00 143.47 1845 104.576 119.899 14.65 0.0083 2005: Transverse Mercator Landsat images of 1999/2000 2015: Universal Transverse Mercator Landsat images of 2007/8
Potentially dangerous glacial lakes in Upper Indus basin Area change of Pot. GLOF Basin Number Max Change Min change Area changed Increase Decrease Astor 9 0.097-0.011 5 4 Chitral 1-0.006-0.006 0 1 Gilgit 8 0.051-0.031 5 3 Hunza 1 0.03 0.03 1 0 Indus 15 0.098-0.009 13 2 Jhelum 4 0.028-0.004 3 1 Shingo 5 0.041 0 5 0 Swat 2 0.036-0.016 1 1 Shyok 6 0.209 0.009 6 0 Total 51 0.209-0.031 39 12
A. Valley lakes are disappearing 1 3
9 B. Glacier fed lakes are growing 8
C. Number of supraglacial lakes are increasing 2 7
2003 2014 D. Surging of glaciers may form blocked lakes
Conclusions Glacier area is decreasing (particularly in mountain glaciers) Number and area of Glacier fed lakes are increasing Valley and erosional lakes are decreasing Out of 51 potentially dangerous glacial lakes, area of 39 lakes are increasing Blocked lakes may form due to surging of glaciers GLOF risk may increase in addition to surging of glaciers
Thanks