DEVELOPING A TRANSPORT MODEL FOR PLASTIC DISTRIBUTION

IN THE NORTH SEA

Dana Stuparu*, Myra van der Meulen, Frank Kleissen, Dick Vethaak, Ghada El Serafy

Outline

• Introduction

• Modeling approach

• Delft3D-PART module

• New modeling features

• Preliminary results

• Synthesis and first conclusions

Modelling approach

River

inputs

Data/

estimates

Multiple year

hydrodynamics

Floating

litter

Suspended

litter

Settling litter

Fragmentation/

decay

Transport

Description

of settling

Litter

characteristics Particle tracking

Observations

data Validation

• Model simulations

• Multiple years

• Accumulation

• Sensitivity

• Type of material

• Hot spots

Model

Results

Delft3D-PART module

Describes the particle transport in a detailed spatial pattern

Instantaneous (ex. from ships) or continuous (ex. river inflows) discharges

Vertical dispersion for well mixed systems

The North Sea

Models provide an important link to

understand the presence of plastic waste

in the environment and anticipate future

concerns.

How does particle modeling work?

The position of every individual particle can be influenced by:

advection

(transport by water flow)

diffusion/dispersion

(a random component)

settling

New features

Plastic Name Density [kg/m3]

Shape Factor Shape Mean Size Standard

Deviation

Polyamide Fibre 1200 0.3 Fibre 2.50E-04 5.00E-04

Polyethylene Fragment 930 0.5 Fragment 1.05E-03 5.00E-04

Polyethylene Pellet 930 1 Granular 3.00E-04 3.60E-04

Polyethylene terephthalate Fibre 1370 0.3 Fibre 2.50E-04 5.00E-04

Polypropylene Sphere 900 1 Sphere 1.25E-04 5.00E-04

Polypropylene Fragment 900 0.5 Fragment 1.15E-03 5.00E-04

Polystyrene Sphere 1000 1 Spheres 1.25E-03 5.00E-04

Polyvinylalcohol Fibre 1190 0.3 Fibre 2.50E-04 5.00E-04

Preliminary results

Different polyethylene sizes, spherical shape and mean diameter:

a) 10 µm, b) 330 µm and c) 5 mm.

• Mean concentration of particles at the water surface [kg/m3] calculated on last day of a simulation run of year 2008.

• Maximum range colour corresponds to a plastic concentration of

10-4 kg/m3 = 0.1 g/m3.

Dynamic visualization

Model validation

Synthesis. Preliminary conclusions

Simulations and multiple scenario analysis allows better understanding of the litter dynamics

Heavy versus light, floating versus sinking litter

Different sizes

Multiple release sources

Modeling can provide information on the areas where data is lacking or limited

Results differ per location (significant/not significant)

New hypotheses can be further explored

Support and advice for clear monitoring questions

Recommendations and follow-up research

Coupling of fresh- and marine modeling to map whole aquatic system

Sensitivity analysis of the river input concentration to model results

Reverse modeling: identifying sources with model

Environmental impact assessment (sediment and water column habitats)

Focus on the impact on particular species

Models can play role in determining regions for monitoring: continue the

validation with field data

Thanks for your attention!