SPOT

Applied regional & global plastic pollution hotspot modelling

 

The Spatio-temporal quantification of Plastic pollution Origins and Transportation (SPOT) model, is a fully integrated GIS-based model for highlighting key hotspots of plastic pollution across the world. The model has been applied on a global scale (publication to be released shortly) but can also be applied at higher resolution over any region with dedicated data inputs for enhanced reliability.

SPOT functions by dividing a large region into smaller areas reflecting the scale at which waste is typically managed (e.g. municipalities). The flows of plastic waste are then mapped within that area according to the waste management in place, including emissions of plastic ‘leaking’ to the environment. With provision of additional data, such as the locations of dumpsites, these emissions can be assigned to the specific positions to reflect reality.

Plastic waste left uncontrolled in the environment is then subject to comprehensive transportation processes involving factors such as wind speed, surface runoff, land use, terrain and river networks to temporally and spatially predict how the plastic moves. This is performed at an item-level so as to account for the critical relationships between the physical properties of an item and their likelihood of being transported by meteorological forces. Importantly, the SPOT model is uniquely able to model both the quantity of plastic entering oceans and therefore becoming marine litter, but also quantify the plastic which becomes entangled on route and accumulates within the environment. This is supplemented by other crucial outputs such as the levels of open burning within an area. The SPOT model therefore is able to provide spatial hotspot maps of an areas plastic pollution whether related to its origins (e.g. source), pathways (e.g. rivers) or fate (e.g. marine litter).

Case Studies

To date the SPOT model has been applied to identify plastic pollution hotspots across South Asia as part of a UN-Habitat project (details to be released soon). Additionally, the SPOT model is also currently being applied across the state of Kerala, India as part of a World Bank project. Further details of this project can be seen in the projects page.