How to manage risk through integrated geohazard assessment Prof. John M. Reynolds Reynolds International Ltd, Mold, UK
Talk outline Introduction Types of disasters within the Himalayas Integrated Geohazard Assessment Disaster Risk Management action planning Recommendations 2
Types of natural disasters Event trigger Flooding events Scale Earthquake Landslides and Landslide- Dammed Outburst Floods Regional depending on the magnitude of the earthquake; multiple river catchments, thousands of km². Cloudburst or exceptionally prolonged heavy rainfall Landslide-Dam and Glacial Lake Outburst Floods, river and surface-water floods, debris flows, mudslides Regional depending on the volume, rate and duration of precipitation; multiple river catchments, thousands of km². Rock-/ice-avalanche/ landslide Landslide-Dam, Glacial Lake Outburst Flood Single catchment, run-out distances hundreds of km. 3
Earthquakes
Earthquakes in and around Nepal, 1900-2017 Source: USGS 190 events M 5 Equivalent to 1.63 earthquakes per year
Earthquake magnitude-frequency relationship: Nepal region Magnitude Number Frequency Total 5 190 1.6 per year 5-<6 163 1.4 per year 6-<7 23 1 every 4 years 7-<8 3 1 every 30 years 8 1 1 every century Data from USGS, 1 st January 1900 to 29 th December 2017 6
Valley-blocking earthquakes after 2015 earthquakes (USGS)
Latest recommendation from ICOLD It is not clear, if the many dams, which had been designed against earthquakes with the pseudo-static method, satisfy today's seismic safety criteria. Welldesigned and well-built dams would usually be safe but others may be deficient, especially those located in areas of moderate to high seismicity. Therefore, it has been my concern... to encourage all dam owners to check the seismic safety of their dams and to use modern methods for the dynamic analysis of dams. Dr Martin Wieland Chairman, Committee on Seismic Aspects of Dam Design, International Commission on Large Dams (ICOLD) 28 th December 2017 8
Reynolds International Ltd s experience: Active in earthquake preparedness for more than 10 years in South America and especially in the Himalayan Region Responsible for developing the earthquake response plan for the British Embassy, Kathmandu, in 2008, tested and proven in 2015 Undertaken research into seismicity and geomorphic responses, especially in relation to landslides and Glacial Lake Outburst Floods Can help hydropower developers/owners refine their seismic risk assessment especially in relation to geomorphic responses to earthquakes 9
Cloudburst: Uttarakhand disaster June 2013, northern India
Kedarnath Vishnuprayag HEP Vishnugad Pipalkoti HEP Uttarakhand, Northern India [background Landsat 8 imagery]
Kedarnath Cloudburst June 2013 Data from Giovanni database Accumulated precipitation 14-20 th June 2013
Events upstream of Vishnuprayag HEP Image date: 9 th November 2011
Events upstream of Vishnuprayag HEP Increase in sediment supply into river Embryonic landslide Image date: 27 th September 2014
400 MW Vishnuprayag HEP, June 2013
Photo courtesy of International Rivers 400 MW Vishnuprayag HEP, June 2013
Reynolds International Ltd s experience: Has recently undertaken forensic analysis of a number of major natural disasters in the Himalayan Region for The World Bank Has been researching the hydro-meteorological influences on hill slope stability Can help hydropower developers/owners in refining their Risk Register and Emergency Response Plans in relation to hydro-meteorological processes 17
Landslides
Jure landslide August 2014, Nepal Image courtesy of www.heraldsun.au 19 Landslide dam, Sun Kosi River
Jure landslide August 2014, Nepal Backwater flood from landslide dam 10 th August 2014 20
Jure landslide August 2014, Nepal Sun Koshi Powerhouse 7 th December 2017 21
Landslides Potential to form a landslide dam?
Active landslides Sun Koshi Valley Impact on access roads and transmission lines
Reynolds International Ltd s experience: Has recently undertaken detailed analysis of large-scale mountain flank stability for hydropower projects in Pakistan and pioneered the development of the Integrated Geohazard Assessment approach in Disaster Risk Management for The World Bank Has been researching the hydro-meteorological and geological influences on hill slope stability Can help hydropower developers/owners by undertaking an integrated overview of hill slope stability within catchments upstream of any hydropower scheme(s) 24
Glacial Lake Outburst Floods
Key locations in Nepal DigTsho
27 Dig Tsho GLOF, Nepal, 4 th August 1985 Westoby et al. (2013)
1984 28
1985 29
Residual lake Breach Houses Tsabai Tsho
Glacial Hazards Glacial Lake Outburst Floods (GLOFs) Reassurances Moraine-dammed glacial lakes are generally stable. GLOFs are NOT commonly triggered by earthquakes. GLOFs are NOT occurring more frequently as a direct result of Climate Change. There are many so-called experts who would like you to believe otherwise. 31
Glacial Hazards Glacial Lake Outburst Floods (GLOFs) For guidance on Glacial Hazard Assessment go to: www.reynolds-international.co.uk/dfid The only freely-available international guidelines 32
Phased approach to Glacial Hazard Assessment Phase 1: Initial catchment screening for glacial lakes Literature search Remote Sensing review of satellite imagery (e.g. Landsat, Google Earth) Phase 2: High Resolution Remote Sensing Assessment Use of UHR satellite imagery (e.g. <1 m ground resolution) Use of temporal series of UHR satellite images Use of stereo images to produce new high-resolution DEM Use of InSAR satellite imagery to detect surface movement Phase 3: Ground Investigation (can also be multi-phase) Reconnaissance Multi-discipline field surveys (e.g. geophysics, topography, bathymetry, etc.) 33
Reynolds International Ltd s experience: Unrivalled experience of working in Nepal since 1994 including: The successful mitigation of Tsho Rolpa in 2000 Many hydropower GLOF analyses Has pioneered the development of the science behind glacial hazard assessment over the last 30 years Responsible for the development of the only GLOF mitigation engineering works in the world to have been tested for real, recognised as having saved 5-6000 lives in 2010. Recognised independently as world leaders in glacial hazard assessment and mitigation. 34
Reynolds International Ltd s experience: No other organisation has the collective experience and expertise to undertake the most technically robust and thorough Glacial Hazard Assessments Contact Reynolds International Ltd for help with your Glacial Hazard Assessment 35
Disaster Risk Management
Timescales for physical processes Physical Processes Time scale Geophysical & Geological Geotechnical Geomorphic Glaciological Climate Change Meteorological Millions of years Orogenic & tectonic; movement & uplift Major slope instability & debuttressing Geomorphic processes Climate Change Thousands of years Deglaciation & rock glacier formation Hundreds of years Historic seismicity Short periods of re-advance & retreat Anthropogenic stimulus Tens of years Especially since 1970s; thawing permafrost Several years Landslides (slow onset) Glacier surges <1 year Landslides (slow onset) Glacier surges Seasons Sudden onset events Earthquakes Landslides, rock avalanches, etc. Geological Rock falls, debris flows, etc. Outburst floods Hydrological Weather, storms, cloudbursts
Timescales for physical processes Time scale Millions of years Thousands of years Hundreds of years Tens of years Several years Geophysical & Geological Orogenic & tectonic; movement & uplift Physical Processes Geotechnical Geomorphic Glaciological Climate Change Major slope instability & debuttressing Geomorphic processes Deglaciation & rock glacier formation Climate Change Historic seismicity Short periods of Anthropogenic Preconditioning re-advance & stimulus retreat Especially since 1970s; thawing permafrost Landslides (slow onset) <1 year Landslides (slow onset) Glacier surges Glacier surges Meteorological Seasons Sudden onset events Earthquakes Landslides, rock avalanches, etc. Geological Rock falls, debris flows, etc. Outburst floods Hydrological Weather, storms, cloudbursts
Association of HEP project studies with physical process types Physical Processes Existing discrete study type Geophysical & Geological Seismic Risk Analysis Geotechnical Geomorphic Glaciological Climate Change Geotechnical Baseline Reports GLOF Assessment Meteorological Hydrological Risk Assessment Recommended additional study Integrated Geohazard Assessment (IGA) By undertaking an Integrated Geohazard Assessment, you maximise your previous investment in Seismic Risk Analysis, Geotechnical Baseline Reports, and Hydrological Risk Assessment, especially when coupled with a Glacial Hazard Assessment. This can result in optimised Risk Register and Emergency Response Plans that can help to reduce the vulnerability of your hydropower scheme and could potentially save you and your investors tens of millions of dollars
Integrated Geohazard Assessment The World Bank guidelines (2017): and, Climate Change Resilience and Disaster Risk Management for the Hydropower Sector* Dam Safety in Nepal *In collaboration with ICOLD and IHA 40
Integrated Geohazard Assessment Event Mapping Incorporation of information from previous reports (GBR, HRA, etc.) Literature search of historic natural events Analysis of satellite imagery to identify geomorphic evidence of previous natural events (landslides, Glacial Lake Outburst Floods, etc.), whether previously reported or not. 41
Event Mapping Nanga Parbat region, northern Pakistan
Integrated Geohazard Assessment Event Mapping Incorporation of information from previous reports (GBR, HRA, etc.) Literature search of historic natural events Analysis of satellite imagery to identify geomorphic evidence of previous natural events (landslides, Glacial Lake Outburst Floods, etc.), whether previously reported or not. Process Identification Method by which physical processes are identified for events recognised by Event Mapping in terms of triggers, preconditioning, ambient environmental conditions, possible sensitivity to climate change, etc. 43
Process Identification Nanga Parbat region, northern Pakistan
Reynolds International Ltd has been: Developing Integrated Geohazard Assessment as part of Disaster Risk Management for The World Bank over the last four years Pioneered the first ever Integrated Geohazard Assessment in the Upper Indus Basin (Pakistan, India and China) in 2014 for USAID Publishing technical papers specifically for the hydropower sector since 2014 Contact Reynolds International Ltd for help with your Integrated Geohazard Assessment 45
Recommendations Undertake a review of your DRM provision and associated Risk Register(s). This can be achieved by: First pass screening of previous studies to see if a Glacial Hazards assessment and any catchment-wide geohazard assessment has been undertaken. If aspects need to be undertaken or updated, ensuring that these studies are commissioned; Updating your Project Risk Register and associated DRM action plans; Undertaking suitable remedial/mitigation work as necessary. Ensure that your Project Risk Register is updated regularly and as frequently as is required in the light of the screening process Contact Reynolds International Ltd NOW to discuss your needs for Integrated Geohazard Assessments and Glacial Hazard Assessments 46
Visit our Stand here at Himalayan Hydropower 2018 for your FREE consultation Suite 2, Broncoed House, Broncoed Business Park, Wrexham Road, Mold, Flintshire, CH7 1HP, UK Tel: +44-1352-756196 Email: info@reynolds-international.co.uk Web: www.reynolds-international.co.uk 47