Transcript Rahman, S.
An Updated Inventory of Glacial Lakes in Hunza and Astore River Basins using Satellite Data By Said Rahman Hopper Glacier Pakistan Glaciers and Glacial Lake Inventory To know about glaciers & glacial lakes Natural Hazards Monitoring Baseline data for climate change research Pakistan Glaciers and Glacial Lake Inventory Develop a database of glacial lakes of northern Pakistan using satellite data To identify existing hot vulnerable glacial lakes Monitoring basis spots and potentially the GLOF phenomenon on a regular Introduction Glacial lake is a lake with origin in a melted glacier Northern Pakistan is home to 5218 glaciers, and 2420 glaciers lakes out of which 52 lakes have been classified as potentially dangerous Introduction Thirty-Five destructive outburst floods have been recorded for the Karakoram Range in the past 200 years Karakoram contains maximum of about 37% of the total glacial lakes followed by the Himalaya with about 34% lakes Introduction Satellite remote sensing plays a very important role in the identification of glacial lakes and potentially dangerous lakes SUPARCO conducted this study based on satellite remote sensing data and glacier lakes having an area more than 0.003 sq.km were mapped Perception about Climate change Bagrot Valley Awareness Level Questions Yes No Don’t Know 1. Climate change has occurred 29 0 0 2. Extreme weather events in the region have been increased 24 5 0 3. Climate change is changing the environment of the region 24 3 2 4. Snowfall events have been decreased 29 0 0 5. Glaciers are melting due to climate change and its size is reducing 28 1 0 73°-03’ to 74°-02’ E and latitudinal range 35°-54’ to 37°-05’ N 74º-24' to 75º-14' E 4º-45' to 35º-38N Data Used Landsat satellite data have been used for identification /mapping of glacial lakes • • • • • a)Jul-2013, path/row (150-35) b)Jul–2013, path /row(150-34) c)Oct-2013, path/row (149-34) d)Oct-2013, path/row (149-35) e) Oct-2013, path/row (149-36) Landsat Data & DEM Methodology Water index Classification Narrow river extraction Wide river extraction Shadow masking Area > 0.003 sq.km Glacial Lakes Map Attribute entry Slope Angle Elevation Lake Class Glacier ID Glacial Lakes Methodology Water class band combination of 5, 4, 2 was used. We used multiband technique, hence MIR (mid infrared), NIR (near infrared) and green band were selected to enhance water class Methodology Supervised classification has been used to classify satellite images for identification of glacial lakes Results of classification were converted into vector data where manual editing was done Spot satellite data were used for further correction. Criteria for Identification of Potentially Dangerous Glacier Lakes Moraine dammed lakes which are still in contact with the glacier Formation of new glacial lakes. With the passage of time the merging of closely spaced supraglacial lakes of smaller area forming bigger lakes this activity of Supra-glacier Lake is an indication that lakes are becoming potentially dangerous. Significant glacier retreat. Criteria for Identification of Potentially Dangerous Glacier Lakes The valley lakes with an area bigger than 0.05 sq.km are considered to be potentially dangerous The position of the lakes near to the ablation area of the glacier. Proximity of the glacial lakes to the parent glacial lakes which are at a distance less than 0.5 km from the mother glacier are considered to be potentially dangerous. Results: Hunza River Basin Total 170 glacier lakes are identified in Hunza river basin out of which 142 are Moraine dammed lakes, 2 are ice dammed lakes, 12 are erosional lakes trough valley , 9 are blocking lakes, 3 are Supraglacier lakes and 2 are other erosion lakes . Remote sensing techniques for the selection of potentially dangerous glacier lakes are ,lake area , slope of the lake greater than 45%(using Aster DEM) and finally we consider the surroundings of the lakes. There is only one potentially hazardous lake on the base of above mentioned criteria in Hunza River Basin. Hunza River Basin Glacial Lakes Hunza-2013 Terminus of Passu Glacier Hopper Glacier Results: Astore River Basin Total 135 glacial lakes are found in Astore river basin out of which 90 are erosion, 15 are Erosion (cirque), 3 are Ice dammed, 3 are blocking, 5 are moraine dammed and 19 are supraglacial glacial lakes. While according to our parameters selection Astore river basin has 4 potentially dangerous glacial lakes for glacial lakes outburst event. Astore River Basin Glacial Lakes Astore-2013 Glacial Lakes Glacial Lakes on Sachen Glacier Sachen-Attaabad Lake Potentially dangerous lakes of Astore River basin Position of potentially dangerous Lakes: 74.678777 75.198435 74.901586 74.902230 34.908647 35.04835 35.095988 35.094760 Table: Glacial Lakes - Hunza FID Shape * Area longitude latitude elevation Perimeter lakes_type 0Polygon 10.75073 74.8649 36.3572 2396 72.11548Erosion Lake(trough valley) 1Polygon 0.0171 75.0761 36.4249 3720 0.72Moraine dammed lake 2Polygon 0.010091 75.0669 36.1428 3399 0.409116Moraine dammed lake 3Polygon 0.009683 74.4944 36.4068 3537 0.469969Moraine dammed lake 4Polygon 0.017977 74.4934 36.4192 3670 0.584269Moraine dammed lake 5Polygon 0.012694 74.1067 36.2318 3222 0.561438Erosion Lake(trough valley) 6Polygon 0.010549 74.5145 36.4508 3900 0.465411blocking lake dis_from gl postion_la 0.664at the end of terminus 0on the mass of glacier associ_gl Glacier_ID PK5Q132F0001, Batura , PK5Q132D0003, Hasanabab, Passu K5Q132E0014 Momhil Yenguiz Har, Balocho PK5Q132k0189 PK5Q14000064 , 5Q132M0029 0medial moraine Hasanabad PK5Q132D0003 0medial moraine Hasanabad PK5Q132D0003 2.167lateral moraine 5.3191existing in the valley 0on the mass of glacier PK5Q132A0012 Hasanabad PK5Q132D0003 remmark s Table: Glacial Lakes - Astore FID Shape * Id Area Longitude Latitude Perimeter Elevation lake_type Position_o Associated 0Polygon 3 0.037898 75.0923 35.3716 0.719982 4629Erosion in glacier valley PK5Q17200057 1Polygon 2 0.042597 75.0905 35.3758 0.897604 4661Erosion in glacier valley PK5Q17200056 2Polygon 1 0.003454 75.0957 35.392 0.235163 4801Supraglacial on glacier mass PK5Q17200055 3Polygon 9 0.010728 75.1525 35.3336 0.418425 4626Moraine dammed end moraine PK5Q17200063 4Polygon 10 0.022775 75.1539 35.3139 0.663126 4706Supraglacial in glacier valley PK5Q17200064 5Polygon 11 0.012354 75.1594 35.3023 0.530353 4748Erosion in glacier valley PK5Q17200065 6Polygon 12 0.028744 75.1629 35.2986 0.879332 4670Erosion in glacier valley PK5Q17200065 7Polygon 13 0.02864 75.1547 35.2828 0.77355 4584Erosion in glacier valley PK5Q17200066 8Polygon 14 0.062431 75.1628 35.2714 1.30044 4787Moraine dam end moraine PK5Q17000080 9Polygon 18 0.015264 75.1608 35.2573 0.540915 4661Supraglacial on glacier mass PK5Q17200067 10Polygon 138 0.185476 74.7854 35.3303 2.07997 3474Moraine dammed in glacier valley PK5Q17200579 11Polygon 136 0.090081 74.616 35.1926 1.291 3599Morain dammed end moraine PK5Q17200564 12Polygon 133 0.003582 74.6118 35.1049 0.239407 4240blocking in glacier valley PK5Q17200157 13Polygon 26 0.016254 75.1938 35.1904 0.541569 4561Erosion(cirque) in b/w glaciers PK5Q17200116 14Polygon 25 0.013654 75.184 35.2012 0.541539 4635Erosion(cirque) in b/w glaciers PK5Q172000078 15Polygon 21 0.006873 75.1528 35.2283 0.346799 4575Erosion in glacier valley PK5Q17000079 16Polygon 17 0.020816 75.1499 35.2488 0.757689 4600Erosion in glacier valley PK5Q17200069 17Polygon 16 0.011685 75.1109 35.2538 0.478874 4486Erosion in b/w glaciers PK5Q17200070 18Polygon 7 0.0214 75.0745 35.2761 0.642649 4483Erosion in glacier valley PK5Q17200111 19Polygon 8 0.057574 75.0703 35.2713 1.46754 4326Erosion in glacier valley PK5Q17200110 20Polygon 6 0.009749 75.0698 35.2846 0.476939 4745Erosion(cirque) in glacier valley PK5Q17200111 Current Status Glacier Inventory of Chitral & Shigar Sub basin has been completed. Glacial lakes inventory of Hunza & Astore sub basin have been completed Future Work Field Expeditions/ Mass Balance Studies Hydrological Modeling Identify the hot spot area for regular monitoring of glaciers Thank You