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11 th International Symposium for GIS and Computer Cartography for Coastal Zones ManagementRecently, the Provincial Government of BC was criticised for its stance on imminent marine debris. According toa spokesperson for the Provincial Government who sent a statement to a news station: “Environment Canada confirmedthere are no “formal plans” for dealing with debris yet, nor has any money been identified to pay for thecleanup, adding the federal government is involved in ongoing discussions with the province and other levels ofgovernment through a Tsunami Debris Coordinating Committee” (Petrovich, 2012).In response, the provincial and federal government revised a two part strategy for debris anticipation. Phase I addressedthe potential impact marine debris can have on aquatic invasive species, radiation testing, marine mammalentanglement, human remains, offshore spills, and various debris (BC Tsunami Debris Management Plan, 2012).Part II of the report is a framework of management for the various government levels. While the Government’s involvementand acknowledgement of the problem is important for the purpose of funding and environmental assessmentwhich will aid clean-up organizations, neither the Provincial nor Federal Government is actively involved inthe mapping or modeling of the debris and the impact it can have on British Columbia’s coast.Building an interactive 3D marine debris visualization sandboxThough the quantification of marine debris is challenging in nature, it does not mean that the small communitieson the approximate 25,000 km (and 900 islands) of BC’s coastline should have to cope with an unknown quantity ofdebris due to the political manoeuvring summarized above.In response to this need, we designed and developed a 3D marine debris visualization ‘sandbox’ – to enable citizensand communities to understand how different quantities and buoyancies of marine debris might move throughand accumulate in bathymetric and beach environments.First we assembled a 3D scene of a well-known part of Vancouver Island’s West Coast – Tofino – combiningtopographic data with bathymetric data digitized from analogue charts. Contour topographic and bathymetric shapefiles were combined and converted into a Digital Elevation Model (DEM). This DEM was converted into a ‘heightmap’that could be imported into the Unity 3D gaming engine. Unity reads the file as elevation pixels and generatesa terrain based on these values, preserving the accuracy of elevation and other spatial properties we controlled inArcGIS.Thirty ‘debris primitives’ were built (i.e. 3D objects that could be assigned any combination of mass, buoyancy).Each object was assigned a mass of 5, 10, or 20 units and buoyancy. A world gravity model was applied to all objects.Lastly, a tidal force was assigned to each object in the z and y (or south-east) direction. The capsules wereplaced on the surface of the water throughout the sandbox. Each capsule was also given a trail property. This propertyreveals the path the object takes as it travels within the environment.When simulated, the physics acting on the objects began to move the capsules towards the shoreline. The capsulesassigned a greater mass dropped to the ocean floor and continued to slowly drift across the floor due to the constant‘tidal force’ and the objects buoyancy force. When the objects made contact with any barrier that overpowered thetidal and buoyancy properties, the capsule ceased to move. Lighter capsules were seen to travel near the surface ofthe water and at a higher speed.Unity 3D allows the user to adjust the visuals and physics within the environment. The purpose of our sandboxvisualization interface is to allow users to create hypothetical scenarios and adjust various properties of the objectsand the physics assigned to them. Additionally, the physics properties of the 3D scene (such as buoyancy, tidal andgravitational force) can be modified at will. Figure 1 provides three views of the objects interacting with the 3Dmarine debris environment.We gave some thought to the aesthetics of the simulation environment. Sand and grass were added to differentiateunderwater and land terrain, and a water mesh which generated waves and reflection further helped to create anenvironment that users could relate to, while still being analytical.71