Climate Change Impact on Water Resources of Pakistan

Transcription

1 Pakistan Water and Power Development Authority (WAPDA) Climate Change Impact on Water Resources of Pakistan Glacier Monitoring & Research Centre Muhammad Arshad Pervez Project Director (GMRC)

2 Outline of Presentation Introduction Significance of Upper Indus Basin GMRC and its Present Role in UIB Monitoring Activities of Glacier Monitoring & Research Centre Overall Progress and Future Plans 2

3 Introduction Pakistan is an agriculture based country and is highly reliant on the Indus irrigation system fed by melt water originating from large scale blue gold glaciers reserves. 3

4 Significance of Upper Indus Basin Glaciers melting under climate change is emerging as one of the biggest challenge for planners and managers of water resources and agriculture around the world The Indus basin in Pakistan contains the largest continuous irrigation system in the world, and millions of people are dependent on the food produced in this area The Karakoram mountain range plays a crucial role in sustaining the Indus basin s water resources through glacial and snow melt hydrological processes Upper Indus Basin (UIB) 4

5 Flows (MAF) Contribution of Snow and ice % Flows Ice & Snow Contributions Contribution of Snow & Ice in river inflows 70% for entire Indus Basin and 85% for Indus Main Stem Any changes in glaciers behavior will have direct impacts on agriculture and food security in Pakistan % 65% 50% Therefore it has become more important to have better knowledge about the status of cryosphere Indus at Tarbela Kabul at Nowshera Jhelum at Mangla Chenab at Marala

6 Role of GMRC-WAPDA in UIB Monitoring High-Altitude Hydro-met Network Hydrologic Modelling Field Investigations 20 AWS UBC Watershed Model Glacier field monitoring - Stake surveys - Snout surveys AWS 13 ARL GR4JSG & SRM Isotope analysis Permafrost monitoring GLOF Studies 6

7 Temperature Trend in Upper Indus Basin (Man Kendall) ( ) Month Shangla Rattu Rama Shogran Ushkore Hushey Kelash Zani Pass Yasin Khod Pass Shendure Ziarat Burzil Khunjerab January February March April May June July August September October November December ANNUAL

8 Temperature Change in UIB ( o C ) ( ) Month Shangla Rattu Rama Shogran Ushkore Hushey Kelash Zani Pass Yasin Khod Pass Shendure Ziarat Burzil Khunjerab January February March April May June July August September October November December ANNUAL

9 Conclusion of Temperature Analysis There is no significant change in the mean annual temperatures of the stations located in the Upper Indus Basin Most of the significant falling trends were seen in the months of July and August which are glacier melt periods, Similarly September also showed significant falling trends for most of the stations. For most of the stations, winter months showed rising trends in which some were significant for January and February.

10 Flow Trends of Indus River at Tarbela Month First year Last Year N Man-Kendall Statistic Total Change (MAF) January February March April May June July August September October November December Annual

11 Monthly Mean Annual Flow Volume Flow Trends of Indus River at Tarbela Year Data Sen's estimate

12 Conclusion of Flow Analysis The flow data of showed an insignificant falling trend in the mean annual analysis. The winter months showed a rising trend with November as significant. Summer months showed an insignificant falling trend. For the months of February, March and May, there was a significant rising trend for the flows

13 UIB Glaciers Selected for Mass Balance Studies 13

14 Ablation Gradient at Passu Glacier # Description August 1990 August 2011 August 2012 August 2013 Changes in Snout at Passu Glacier from 2011 to Net ablation at PS profile (NAS) cm/day 2 Net ablation at PG Profile (NAG) cm/day ABL = (NAS-NAG) cm/day Elevation PS (ES) m.a.s.l Elevation PG (EG) m.a.s.l ELV (EG-ES) m Ablation Gradient cm/day/100- m between the PS & PG profiles Findings Glacier has receded in 2012 relative to its position in 2011 A part of glacier at its terminus detached from the main body of the glacier and melted during 2012 The glacier snout position was unchanged in 2013 The comparison of the snout survey from to showed that terminus of the Passu glacier has advanced about 20 m 14

15 Ablation Rate (cm/day) Map of Barpu Glacier Melt Rates for Barpu Glacier (Jul-Sep, 2014) R² = Barpu Glacier Snout Barpu Glacier Data shows that the ablation rate drastically reduces with an increase in the thickness of the debris cover, especially over 2 cm R² = Debris Thickness (cm) Relationship between debris thickness and ablation rates 15

16 Melt Rates for Biafo Glacier (Jul-Sep, 2015) Net Ablation Sr. No. Profiles Month Rates 1 July (11-31) 6.8 Mango Profile 2 August July (11-31) 6.5 Baintha Profile 4 August 5.0 Findings Ablation rate at Baintha profile is same i.e., 6 cm/day, as compared with the ablation rate of the study in 1985 The spatial and temporal ablation rates didn t show any significant difference at both profiles instead of very higher difference in temperatures (on-ice) At Mango, for example, the average temperature (on-ice) was 25% higher but the ablation rate was only 4.5% more than the Baintha during July Similarly, the glacier velocity at Baintha also was same as measured during 1985 These latest results (i.e. from the data collected during 2015) reveals that no significant change in ablation rate and glacier velocity has occurred as compared with the results of

17 Hydrological modelling studies on Source Platform with collaboration of CSIRO,AUSTRALIA Correlation 0.83 Volume Bias Results of Flows calibration at Dainyor Bridge, Hunza River Basin 17

18 Elevation (m.a.s.l) m m 114 m Elevation (m.a.s.l) 81.8 m m 86.9 m Raikot Glacier Depth Profiles (2016) Profile 1 PR1-1 RC-3 PR Glacier Surface Glacier Bed Distance from Glacier's Left Edge (m) 3550 Profile 2 PR2-1 RC-6 PR Glacier Surface Series Distance from Glacier's Left Edge (m) 18

19 Glacier Snout Surveys Snout Surveys planned: 50 Conducted for 37 glaciers so far Monitoring and mapping of fluctuations in their terminus They will serve as a strong control points on the ground for the verification of remotely sensed and interpreted images 19

20 Isotope Study for Indus River above Tarbela Samples have been collected and will be sent to China for lab analysis 20

21 Permafrost Monitoring A permafrost monitoring equipment has been installed in Deosai DCP Station. 21

22 GLOF Study Glacier Monitoring Research Centre (GMRC) was continuously monitoring Khurdopin Glacier and the Lake area through field visits and RS analysis from 2015 and two reports were generated in this regard GMRC was the only entity to reach the lake physically. 22

23 1 st Visit Observations The Khurdopin Glacier has advanced and raised the river bed that has resulted the formation of glacial lake in the upstream side by blocking the flow of Virjerab Glacier Ice dammed lake was formed which was nearly 40-50m long, 8-10m wide 4-6m deep With the help of RS/GIS it was observed that due to further surging of glacier the length of lake was increased about 400m till mid of June The water continuously draining out through the snout of the glacier and the lake disappeared in July-August 2017 Recommendations Another assessment of Khurdopin glacier was suggested in the month of Sep 2017 so that the probable impact of newly developed lake may be predicted Ice blocks were falling from Khurdopin Glacier into the lake blocking location but the flow of the river overtopped these ice blocks and washed away them within hour or two. Awareness sessions can be helpful to reduce the mental stress of local people and calamity from the GLOF event If the Khurdopin Glacier continues to advance then there is a chance of the large glacial lake development that will be hazardous to downstream inhabitants, vegetated areas and public infrastructure 23

24 2 nd Visit Observations GMRC Team revisited the lake for the assessment in Sep-Oct 2017 The lake, developed due to surging of glacier as observed in May-June 2017, has been drained The Khurdopin Glacier was further advanced towards the opposite mountain as compared with the previous observations made in May-June 2017 and blocked the river path completely at some locations The water continuously draining out through the snout of the glacier and the lake disappeared in July-August 2017 Recommendations Drainage of the lake by controlled breaching for the formation of spill channel to increase the drainage rate thereby reducing the risk of high flow Dam Breach Study to assess the situation D/s in case of a GLOF event Safe evacuation of the inhabitants to avoid any loss of lives The advancement of Khurdopin Glacier continued in 2018 as well and due to complete blockage of the stream, the lake was again started developing in November It was apprehended that blockage of crevasses due to falling debris may block the flow subsequently may result in development of big lake which may cause high flood event in coming summer season As a result of glacier surge the process of deformation has been accelerated and large numbers of crevasses have been developed in the glacier Continuous monitoring of lake formation using RS/GIS and physical verification at lake site The breakage of glacier and water flow through crevasses may result in loss of mass at snout due to the detachment of lowermost portion of glacier snout Early Warning Arrangement 24

25 RS/GIS Analysis Development of Lake from to using Landsat 8 Satellite Images downloaded from an approximate length of lake Km and ~ 175m in width, which is very close to what the local of the area informed telephonically. 25

26 NDMA Initiative NDMA took initiative and form a ToE. Two experts Mr. Mujahid Tanveer Ahmed (Director Glaciology) and Mr. Syed Hammad Ali (Glaciologist) from GMRC WAPDA As a result of that meeting, a Heli visit was arranged by NDMA. observed that water level of the lake has been lowered due partial drainage from the lake but still there is every chance of increase of lake level as the upstream discharge increases. It will be useful to make arrangements on urgent bases to clear the path of water through controlled breaching at blocked positions, if Khurdopin glacier continue surge in the same direction it may result in formation of big Glacial Lake. In this regard April to June 2018 may be critical months and situation may face a GLOF event most probably in July-August,

27 Overall Progress and Future Plans High-Altitude Weather Stations It is planned to further enhance the AWS network at high altitude. ARL For Glacier Fed Streams 13 ARL are planned to install in the glacier fed streams for the estimation of future water availability Glacier Field Monitoring Three (3) of the major Glaciers have been investigated for stake ablation out of five (5) selected for the Mass-Balance studies and Thirty Seven (37) out of fifty (50) of them for the monitoring and mapping of fluctuations in their terminus. Hydrological Modeling Flows for Hunza River Basin has been calibrated. The flows for other sub-catchments will be calibrated and future climate scenarios will be used to estimate the availability of flows from the sub-catchments of UIB. (C-4 funding) 27

28 Existing and Proposed GMRC AWS and ARL Stations 28

29 THANKS 29