Introduction to Underwater Acoustics Simulator Poul Kronborg Product Area Owner, Marine MIKE Software Products DHI pok@dhigroup.com
Module Overview for Marine MIKE Software: Release 2014 Hydrodynamics Sediments Environment Waves MIKE 21/3 HD MIKE 21/3 ST (Sand transport) MIKE 21/3 AD (Advection- Dispersion) MIKE 21 SW (Spectral Waves) MIKE 21/3 MT (Mud transport) MIKE 21/3 OS (Oil Spill) MIKE 21 BW (Boussinesq Waves) Others: MIKE C-Map MIKE Animator LITPACK MIKE 21/3 PT ECO Lab ABM Lab DHI
Module Overview for Marine MIKE Software: Release 2016 Hydrodynamics Sediments Environment Waves MIKE 21/3 HD MIKE 21/3 ST (Sand transport) MIKE 21/3 AD (Advection- Dispersion) MIKE 21 SW (Spectral Waves) MIKE 21 SM (Shoreline Morphology) MIKE 21/3 OS (Oil Spill) MIKE 21 BW (Boussinesq Waves) MIKE 21/3 MT (Mud transport) ECO Lab DHI Others: MIKE C-Map MIKE Animator LITPACK MIKE 21/3 PT ABM Lab UAS (Underwater Acoustics)
Module Overview for Marine MIKE Software: Release 2017 MIKE Operations for Forecasting Hydrodynamics Sediments Environment Waves Maritime MIKE 21/3 HD MIKE 21/3 ST (Sand transport) MIKE 21/3 AD (Advection- Dispersion) MIKE 21 SW (Spectral Waves) MIKE 21 MA (Mooring Analysis) MIKE 21 SM (Shoreline Morphology) MIKE 21/3 OS (Oil Spill) MIKE 21 BW (Boussinesq Waves) MIKE 21/3 MT (Mud transport) ECO Lab Others: MIKE C-Map MIKE Animator DHI Littoral Proc. (New Litpack) MIKE 21/3 PT ABM Lab UAS (Underwater Acoustics)
Marine MIKE software: Latest Developments Performance: Parallelization Linux porting Support of GPU s Remote Execution Facility SaaS (MIKE in the Cloud) Engine enhancements: Nearfield/Farfield integration New dike structure with overtopping Structure Improvements Flather boundary and Q/h boundaries Time-varying bathymetries Litpack Re-engineering New Oil Spill Module Agent Based Modelling Productivity tools: Scour Calculation Tool Enhancements of Climate Change Editor MIKE Animator enhancements Mesh Generation improvements Earthquake bathymetry adjustment New Cyclone Tool Fully Spectral Wave Boundary Generation Random Wave Generation Enhancements Software Development Kit US Units Easy data access: Introducing online WaterData Improvements in the Global Tide Model DHI
Water is an excellent medium for sound transmisson Sound is more than four times faster underwater compared to air and there is less attenuation
Sound is important for marine life 10
Senses underwater Smell - No receptors Taste - Limited Touch Short range Visual Short range Sound Effective, fast, long-range DHI
Marine mammal hearing 160 140 SPL (db re 1 µpa) 120 100 80 60 40 20 0.01 0.1 1 10 100 Frequency (khz) Bottlenose dolphin (Johnson 1967) Risso's dolphin (Nachtigall et al. 1995) Striped dolphin (Kastelein et al. 2003) Killer whale (Szymanski et al. 1999; Behaviour) Killer whale (Szymanski et al. 1999; ABR) Harbour porpoise (Kastelein et al. 2002)
Fish hearing 160 150 140 130 SPL (db re 1 µpa) 120 110 100 90 80 70 60 50 10 100 1000 Bass (Nedwell et al. 2004) Cod (Offut 1974) Cod (Hawkins & Myrberg 1983) Dab (Hawkins & Myrberg 1983)) Bass (Nedwell et al. 2004) Herring (Enger 1967) Pollack (Chapman 1973) Pollack (Chapman & Hawkins 1969) Atlantic Salmon (Hawkins & Johnstone 1978) Little Skate (Casper et al. 2003)
Marine sound sources Boyd et al. 2008
Risk based approach to noise assessment What is the problem? How far does the sound spread and how many animals are in range of the sound? How do they react to the sounds? How can we mitigate impacts? 6/29/2016 15
Detection Masking Response TTS-PTS Injury TTS = Temporary threshold shift PTS = Permanent threshold shift
Detection Depends on source strength, sound spread and different ambient noise conditions (Close range - > 100 km) 17
Masking Whales Fish Seals & Sea Lions Toothed Whales 200 k 1 Hz 10 Hz 100 Hz 1 khz 10 khz 100 khz Shipping (Southall & Hatch in OSPAR 2009)
Response Age Condition Source Channel Sex Social state Properties -duration -transient / continuous Behavioural state Season
Response Significant decline in catch rate during and after seismic exposure 5 days to recover Effects 20 nm Pearson et al. 1992; Engas et al. 1996; Slotte et al. 2004
Risk management Source mitigation (e.g. dampening) Channel mitigation (e.g. Bubble curtains, NMS, Helmholtz Res) Receiver mitigation (Wochner et al. 2015; Schiedek et al. 2015 ) Werner Piper 6/29/2016 23
Different approaches Simulate Sound Propagation: Underwater Acoustic Simulator (UAS) Undertake EIA: Underwater Acoustic Analyzer (UAA) Dynamic Risk Assesment: Agent Based Modelling (ABM Lab) 6/29/2016 24
Underwater Acoustic Simulator The UAS Engine a. Sound propagation b. Broad band noise source c. Range dependent d. Ambient conditions DHI
Underwater Acoustic Simulator in MIKE Accounting for ambient conditions a. Bathymetry b. Temperature c. Salinity d. Absorption in the seabed e. Volume attenuation in the water significant for high frequencies DHI
Bathymetry and Transects from MIKE HD DHI
Broad band noise source in 1/3 Octave DHI
Water phase DHI
Seabed Geological profile DHI Femern A/S
Specifying Outputs and resolution DHI
Work Flow - Noise Impact Assessment Marine species filter Noise maps Impact ranges (PTS/TTS) Pinnipeds High Freq. Cetaceans DHI
Some raw simulation results Results in 1/3 Octave bands: 20 Hz 5 khz DHI *Sound exposure lever (SEL) is a measure of the total energy of the noise normalised to 1 second.
Validation Lloyds Mirror case (the sea surface acts like a mirror for acoustic energy) Ideal Wedge (Jensen and Ferla,1990) DHI
Empirical UAS Validation: Measurements at Belwind OWF DHI 29 June, 2016 #37 (Degraer et al. (2010): Belwind Phase 1 windfarm, foundation B10)
UAA development (Underwater Acoustics Analyzer): On-going UAS: Model for the simulation of TL (CPU consuming) UAA: Tool for post-processing of UAS results (instantaneous): Scaling of source spectrum Apply mitigation spectrum Calculate relevant metrics (SEL, SPL-zp, etc.) Calculate cumulative impacts (noise dose, etc.) Make weighting of received spectrum e.g. M-weighting Calculate impact ranges based on various impact criteria for specific receptors Make transect plots, line plots, spectral plots In short: Prepare your Environmental Impact Asessment applying the UAA DHI 29 June, 2016 #38
Noise Dose Impacts TTS: acoustic dose TTS single strike = 700 m (SL = 207 db re 1µPa 2. s, N = 2400 strikes, TL = 15 log (r) 6/29/2016 42
TTS: acoustic dose TTS single strike = 700 m TTS 1 h = 12.5 km (SL = 207 db re 1µPa 2. s, N = 2400 strikes, TL = 15 log (r)) 6/29/2016 43
Beluga whale sound response modelling Dynamic Risk Assessment Model for Acoustic Disturbance DHI 29 June, 2016 #44
Marine Strategy Framework Directive Acute exposure to loud, low and mid frequency impulsive sounds Chronic exposure to continuous low frequency sound Gaps in distribution due to behavioural alterations (11.1.1) Communication difficulties caused by low frequency noise (11.2.1) (OSPAR 2009; Tasker et al. 2010)
Exposure criteria Update on Southall 2007 noise exposure criteria in preparation NOAA Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammals in preparation DHI 29 June, 2016 #46
Questions DHI