«Regional forecasting service for rainfall-induced landslides in Norway» Graziella Devoli NVE/UiO Section for Forecast flood and landslide hazards Hydrology Department, NVE [email protected]
October 2017 Example of EWS for Norway Norway: Nordic country, high-income country • Climate: Artic and Continental climate • Geology: Caledonian metamorphic rocks and quaternary fluvial and glacier sediments • Type of landslides: debris flows, debris avalanches, debris slides, small and shallow soil slides along roads, railways, slush flows (also rock slides that can generate tsunamis, sensitive clay slides and rock falls) • Main triggering of landslides: • Rainfall (Large scale, low pressure systems, extra tropical cyclones; local summer convective rainfall) • Snowmelt • Type of landslide material: moraine 2 deposits, fluvial, colluvial deposits Rests of Hurricanes Maria and Nate, (Kristin), 14 sept. 2005 Norway
Many debris slides and debris flows in Western Norway. This landslide at Hatlestad, Bergen, killed 3 people, 14 september 2005 Forecasting services at NVE
Flood: 1989 ■ Flood forecasting ■ Landslide & debris flows ■ Snow avalanche ■ Monitoring and warning of large unstable rock slopes (..tsunamis or valley blockage)
Unstable rock Snow avalanche: Debris flows/debris slides: slopes: January January 2013 October 2013 2014
Norwegian Water Resources and Energy Directorate 4 Water stream flow, 10 June 2011 Photo NVE
Debris flow Eikesdalen, july 2014 Photo S. Tjelle
■ Type of landslides: Shallow soil slides, debris slides/avalanche and debris flows, slush flows Slush flow, Dovrefjell, Mai.2010 Snøhetta Foto: Adressa.no (runout 3-5 km; velocity 5m/s) ■ Triggered by rain, rapid snowmelt or a combination ■ Yearly severe economical losses along roads and railway Norwegian Water Resources and Energy Directorate 5 Snowmelt induced spring flood
Gudbrandsdalen, East Norway, summer 2011 Foto Scanpix
Norwegian Water Resources and Energy Directorate 6 Heavy rain induced flood
Flåm Foto vg.no
Odda, West Coast. October 2014 Foto NRK.no
Norwegian Water Resources and Energy Directorate 7 Summer showers induced Flash flood/Debris Flows
Notodden, South Norway - 23 juli 2011 Foto J. Simonsen
Norwegian Water Resources and Energy Directorate 8 Growing problem?
Compensations paid 1996-2015
Events in 2013: Debris flows Soil slides Clay Debris (unspec.) Snow avalanches
Millions NOK Norwegian Water Resources and Energy Directorate 9 Warning portal: varsom.no
Norwegian Water Resources and Energy Directorate 10 Use of landslide warning
Click in the Warning-area
Test message and susceptibility map (brown area)
Norwegian Water Resources and Energy Directorate 11 Examples of Warnings, May 2013
15th 16th-19th 20th 21st
th th 22nd 23rd 24 -30
Norwegian Water Resources and Energy Directorate 12 Extreme situation! Landslide awareness levels Be prepared! < 50 year flood
Be aware! < 5 year flood General safe conditions! 0-2 days 4-8 days Extreme situation Expected many landslide Sever situation events, several with Expected many landslide considerable consequences. events, some with considerable Extensive flooding, erosional About 30-60 days consequences. damage and flood damage to Extensive flooding, erosional buildings and infrastructure. Situation that requires About 300 days/year damage and flood damage monitoring Generally safe conditions Expected some landslide events, Man-made landslide certain large events may occur. Local flooding and/or erosional Number of days in period 2012-15 damage
Norwegian Water Resources and Energy Directorate 13 Hazard assessment: steps
1. identify and notify local emergency authorities and the public about potentially dangerous hydrological situations (for 3 days ahead); 2. information about an ongoing situation and expected development so that the situation can be handled best possible locally.
Norwegian Water Resources and Energy Directorate 14 Daily Weather forecast (Temperature and precipitation) is received from meteorological institute and used as input in hydrological models
Nedbør
Nedbør
Temperatur
interpolated 1x1 km2 grid in xgeo.no Weather forecast Norwegian Water Resources and Energy Directorate 15 Norwegian Water Resources and Energy Directorate 16 From the HBV model several simulated parameter are obtained every day
Norwegian Water Resources and Energy Directorate 17 Besides simulated parameters we use real-time observations
Norwegian Water Resources and Energy Directorate 18 Landslide data
From xgeo.no
Norwegian Water Resources and Energy Directorate 19 Who/where landslide data are registered?
Road maintainance - Regobs.no El Rapp!
Road authority intern Personnel on controll duty
Other Landslide database NSDB: institutions, skredregistrering.no Private Skrednett.no consultants… Limitations: double registrations
Norwegian Water Resources and Energy Directorate 20 Landslide thresholds
Water supply
Soil water content Based on empirical data over 209 landslide events, but regional corrections are in progress
Norwegian Water Resources and Energy Directorate 21 Representation of the thresholds (Hydmet), xgeo.no
20th May (morning)
21st May (morning)
22nd May (morning)
22nd
Landslide hazard assessment is based on the thresholds, other simulated hydrological parameters, real time observations, susceptibility maps and expert-knowledge
Norwegian Water Resources and Energy Directorate 22 Work in progress to increase precision in warnings: Forecasted hydro-meteorological index (soil saturation and rain & snowmelt) combined with a susceptibility maps at catchment level (geology, geomorphology, slope, yearly rainfall, various runoff variables)
Hydmet: Thresholds (only Landslide susceptibility map at Hydmet GEO: Thresholds hydrometeorological conditions) catchment level corrected with landslide susceptibility
Norwegian Water Resources and Energy Directorate 23 Norwegian Water Resources and Energy Directorate 24 Landslides, Eastern Norway May 2013
Bilde
Issued warning message
Observed landslides
Photo: RØ, NVE
Norwegian Water Resources and Energy Directorate 25 Weekly rainfall from 15th to 22nd may 2013
New thresholds for Observed landslides south-eastern Norway the 22th May 2013
Foto NTB scanpix
Norwegian Water Resources and Energy Directorate 26 Operational since 2013, after a period of test (2011-2012)
Flood/snow avalanche and landslide forecasting services
Synergy effects: Weather forecasts, hydrological models, observations. Development of common decision tools – warning portals, organisation/personal
27 Tools & apps to monitor/record events, evaluate and communicate natural hazards
Elrapp Road operation data base for contractors & road authority
regObs.no Observations registered by professionals and public (Crowdsourcing) Retriever: Media monitoring
xgeo.no : Expert tool to evaluate flood, landslide and avalanche hazards Senorge.no: Public version
varsom.no Warning portal on flood, landslide and avalanche hazards on regional scale
Norwegian Water Resources and Energy Directorate 28 Organization
■ 8:00-21:00 nationwide forecasting and warning service
■ About 12 forecasters from NVE and 2 from NPRA (Roads Administration) Multidisciplinary teams: Hydrologists, hydrogeologists, geologists
■ 1 forecaster on duty for one week (+ 1 second call in working time
■ Daily briefing at 9:00 with a meteorologist from MET Norway
Norwegian Water Resources and Energy Directorate 29 Management and economy $ ■ Estimated costs for landslide service (in 2016): ■ 14,7 mill. NOK (1.8 mill US$, but 1.2 millUS$ are in common with snow avalanche forecasting service) ■ Includes forecasters compensation, research & development, management, etc.
Norwegian Water Resources and Energy Directorate 30 • Few warnings and flood events in 2015 and 2016
Norwegian Water Resources and Energy Directorate 31 Evaluation of the system
HEC method
1 Between yellow/orange or orange/red level 32 International workshop October 2016
• reliable landslide data, • thresholds, • validation of warning, • communication
50 participants From Europe: BGS, INERIS, CNR, ARPA PIEMONTE, IMO, SGI, WLS, Wildbach Norway:NVE, MET, SVV, Bane NOR, NGU, NGI, UiO USA: USGS
Norwegian Water Resources and Energy Directorate 34 More information about the workshop: http://www.varsom.no/nytt /nyheter-flom-og- jordskred/better-landslide- warning-to-be-better- prepared/ http://www.varsom.no/nytt/nyheter- flom-og-jordskred/workshop-on- regional-landslide-early-warning- systems/
Norwegian Water Resources and Energy Directorate 35 References (Norway)
■ Piciullo L., Dahl M-P., Devoli G., Colleuille H., Calvello M. (2017). Adapting the EDuMaP method to test the perforamnce of the Norwegian early warning system for weather-induced landslides. Nat. Hazards Earth Syst. Sci., 17, 817-831. ■ Devoli G., Jorandli L., Engeland K., Tallaksen L.M. (2017), "Large-scale synoptic weather types and precipitation responsible for landslides in southern Norway". Proceedings of World Landslide Forum 4, 29 May-2 June 2017, Ljubljana ■ Devoli G. (2017) Workshop «regional early warning systems for rainfall- and snowmelt-induced landslides. Need for an international forum?» NVE rapport nr. 4/2017. Norges vassdrags- og energidirektorat, Oslo, Norge. ■ Bell R., Cepeda J., Devoli G. (2014). Landslide susceptibility modeling at catchment level for improvement of the landslide early warning system in Norway. Proceedings 3rd World Landslide Forum 3, 2-6 June 2014, Beijing. ■ Boje S, Colleuille H, Cepeda J, Devoli G (2014). Landslide thresholds at regional scale for the early warning system in Norway. Proceedings 3rd World Landslide Forum 3, 2-6 June 2014, Beijing. ■ Devoli G., Kleivane I., Sund M., Orthe N-K., Ekker R., Johnsen E., Colleuille H. (2014). Landslide early warning system and web tools for real-time scenarios and for distribution of warning messages in Norway. Proceeding IAEG 2014, 15-19 September, Torino, Italy
Norwegian Water Resources and Energy Directorate 36